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A novel anti-cytomegalovirus (CMV) agent, letermovir (LMV), could reportedly improve the outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) recipients because of its high potential to prevent CMV reactivation. Therefore, 685 Japanese allo-HCT recipients, of whom ~80% had a high risk of CMV reactivation, were retrospectively analyzed to assess the impacts of prophylactic LMV on the incidence of clinically significant CMV (csCMV) infection as well as their transplant outcome. By comparing 114 patients who received LMV prophylaxis for a median 92 days to 571 patients without prophylaxis, we observed that prophylactic LMV could significantly (1) reduce the 180-day cumulative incidence of csCMV infection (44.7 vs. 72.4%, p

Herpesviruses such as herpes simplex virus (HSV) type 1 and 2, varicella-zoster virus (VZV), and cytomegalovirus (CMV) maintain lifelong latency in the host after primary infection and can reactivate periodically either as asymptomatic viral shedding or as clinical disease. Immunosuppression, including biologic therapy, may increase frequency and severity of herpesvirus reactivation and infection. Licensed biologics are reviewed regarding their risks of potentiating HSV, VZV, and CMV reactivation and infection. Approaches to prophylaxis against HSV, VZV, and CMV infection or reactivation are discussed.

Cytomegalovirus (CMV) reactivation has been described in adults with critical illness caused by diverse etiologies, especially severe sepsis, and observational studies have linked CMV reactivation with worse clinical outcomes in this setting. In this study, we review observational clinical data linking development of CMV reactivation with worse outcomes in patients in the intensive care unit, discuss potential biologically plausible mechanisms for a causal association, and summarize results of initial interventional trials that examined the effects of CMV prevention. These data, taken together, highlight the need for a randomized, placebo-controlled efficacy trial (1) to definitively determine whether prevention of CMV reactivation improves clinical outcomes of patients with critical illness and (2) to define the underlying mechanism(s).

T-cell prolymphocytic leukemia (T-PLL) is a rare, aggressive hematologic malignancy with a poor prognosis. Alemtuzumab (Campath) remains the cornerstone for treatment, with an 80% complete response (CR). Hematopoietic stem cell transplant (HSCT) is considered the standard of care as consolidative therapy in eligible patients. However, allogeneic stem cell transplant is also complicated by increased rates of infections from chemotherapy, acute graft-versus-host disease (GVHD), and chronic GVHD. This review aims to report the available literature on the efficacy and complications of consolidative HSCT. It also discusses the importance of patient selection and pre- and post-transplant complications including atypical infections and GVHD.

Cytomegalovirus (CMV) viral load after liver transplantation (LT) is controlled by cell mediated immune responses (CMI). Quantification of CMV-specific T-cells may identify patients who control CMV spontaneously and avoid expensive and potentially toxic antiviral therapies. Prospective post-LT clinical, virological and immunological monitoring was carried out up to 1-year post-LT in a cohort of adult recipients. The CMV-specific T-cell response was characterized using flow cytometry intracellular cytokine staining in 49 LT recipients-R (79.6% R+, 20.4% R-). CMV infection occurred in 24 patients (18 D+/R+ and 6 D+/R-). Only patients with undetectable polyfunctional CMV-specific CD4+ T-cells developed CMV infection. Predictive models showed that polyfunctional CMV-specific CD4+ T-cells pre-existing before LT are protective for CMV reactivation posttransplantation. Quantitation of CD4+ T-cell responses to CMV may be a useful marker for spontaneous control of viral replication to tailor antiviral prophylaxis after LT.

Key Points CMV reactivation was associated with the maturation of reconstituting NK cells from BM, but not PB, unrelated donor grafts. CMV reactivation was associated with CD8+, but not CD4+, T-cell recovery, more so after BM than PB unrelated donor grafts.

International audience; Background: Co-infections may represent substantial diagnostic and treatment challenges. Aim: To the better of our knowledge, we describe the first case in the literature of congenital Cytomegalovirus (CMV) infection following maternal CMV non primary infection contemporary to varicella during pregnancy. Case Presentation: A pregnant woman had a varicella during her pregnancy. Congenital CMV infection was fortuitously discovered in the neonate owing to a universal CMV screening. Retrospective analysis of maternal serums during pregnancy showed CMV reactivation. We aim to highlight that CMV reactivation could be due to varicella and discuss if it could facilitate the transplacental transmission of CMV. Conclusion: This case report emphasizes neonatal CMV screening, and warns against dual maternal infection especially because this may be at particular risk of transmission to the fetus.

Cytomegalovirus (CMV) reactivation in allogeneic hematopoietic stem cell transplantation (allo-HSCT) causes significant morbidity and mortality. This study aimed to investigate the clinical characteristics of children diagnosed with CMV GI disease after allo-HSCT. This was a retrospective cohort study of patients19 years old that underwent allo-HSCT during an 11-year period. Of the 756 patients, 55.5% (n = 420) experienced post-transplant CMV DNAemia, 2.9% (n = 22) were diagnosed with proven CMV GI diseases, and the highest incidence was found in familial mismatched donors (5.6%, P = 0.029). CMV GI disease was diagnosed100 days of transplant in 68.2% (n = 15/22), and 13.6% (n = 3/22) did not have concurrent CMV DNAemia. Patients were divided into five groups based on the patterns of CMV viremia initiation and duration post-HSCT. At 3 months post-transplant, lower CD4+ (P = 0.006) and CD8+ (P = 0.011) T-cell counts were observed in patients with waxing and waning CMV viral load titers100 days post-transplant (groups 1-3) compared to those with CMV DNAemia only prior to 100 days post-transplant and those without concurrent CMV DNAemia (groups 4-5). A higher 1-year all-cause mortality was observed in groups 1-3 compared to groups 4-5 (42.8% vs. 0%; P = 0.051). Active surveillance and aggressive management of CMV reactivation is crucial, especially in children with delayed CD4+ and CD8+ T-cell reconstitution after allo-HSCT.

Long term erythropoietic reconstitution after allogeneic hematopoietic stem cell transplantation (alloHSCT) has not been extensively studied. We aimed to describe erythropoietic reconstitution as an indicator of long-term graft function by modeling hemoglobin levels during the first 3 years post HSCT in pediatric patients. We retrospectively included 414 patients and 11,957 measurements. The largest hemoglobin increase was at day 45 and levels reached a steady state at day 648 with a level of 7.48 mmol/L. In patients transplanted for hematological malignancies hemoglobin levels normalized faster (p < 0.0001). Increasing patient age correlated with faster recovery (p < 0.0001), while donor age had no influence. Conditioning, donor type and graft source did not influence recovery significantly. In the ABO mismatched group there was a transient negative effect on hemoglobin levels, and a delay in reticulocyte recovery (21 vs. 19 days; p = 0.012). In contrast, hemoglobin levels reached a higher plateau beyond 9 months in these patients (p < 0.0001). After alloHSCT, experiencing a CMV reactivation negatively affected reconstitution (p = 0.034), while EBV reactivations and acute graft vs. host disease did not. In summary, erythropoietic recovery was mainly influenced by patient factors and primary disease, and less influenced by donor factors.

We performed multivariable analysis of potential risk factors (including cytomegalovirus [CMV] reactivation) for clinical outcomes by day 28 (death or continued hospitalization, ventilator-free days, intensive care unit (ICU)-free days, hospital-free days) from pooled cohorts of 2 previous prospective studies of CMV-seropositive adults with sepsis. CMV reactivation at any level, >100 IU/mL, >1000 IU/mL, peak viral load, and area under the curve were independently associated with the clinical outcomes. We identified the potential effect size of CMV on outcomes that could be used as end points for future interventional trials of CMV prevention using antiviral prophylaxis in ICU patients with sepsis.

Key Points Vancomycin exposure in the pre-engraftment period was associated with an increased risk for CMV reactivation after allogeneic HCT. Some gram-positive bacteria may protect against CMV reactivation.

Background: The success of hematopoietic stem cell transplantation (HSCT) depends upon donor stem cell harvest. Conventionally CD34 has been considered as marker of hematopoietic stem cells; however, the association of CD34+ cells with post-transplant outcomes has not been consistent. Current efforts are focused on identification of new markers that serve as potential predictors of post-transplant clinical outcome. Methods: This study includes donor harvests collected from twenty-three allogeneic donors during period 2008-2009 and respective transplant recipients followed for clinical outcomes till March 2019. Percent CD26+ and CD34+ cells in PBSC harvest were analyzed using flow cytometry. Infused dose of CD26+ and CD34+ cells was evaluated for its association with various clinical outcomes. Findings: Median donor and patient age was 28 and 24 years, respectively; 13 and 17 were males, respectively. Median CD34br CD45lo HSC expression was 0·57% (IQR 0·24-1·03) while median CD26 expression was 19·64% (IQR 8·96-33·56) of all nucleated cells. Lower CD26 expression correlated with lower risk of developing aGvHD (p=0·056). Higher infused CD26+ cell dose was associated with early WBC engraftment (p=0·004), higher risk of CMV reactivation (p=0·020) and a tendency to lower overall survival (p=0·066). There was no correlation between infused CD26+ and CD34+ cell dose. Interpretation: This forms the first study suggesting CD26 expression on donor harvest and CD26+ cell dose may serve as potential markers for transplant outcomes. If validated further in larger studies, it may be helpful in management of GvHD prophylaxis and improving survival with risk-based tailored therapeutics. Funding Statement: This study was funded by Indian Co-operative Oncology Network- Academic Research Organization, Mumbai, India. Declaration of Interests: Authors declare no potential financial conflicts of interest. Ethics Approval Statement: The study was approved by the institutional ethics committee. All patients and donors provided consent for study participation.

development of cytomegalovirus (CMV)-specific CD8+ T cell response is crucial in preventing symptomatic CMV infection specially, in stem cell transplant (SCT) patients. The aim of this study was to evaluate CMV-specific CD8+ T cell reconstitution in allogeneic SCT recipients and to study the possible association between CMV-specific CD8+ T cell recovery with protection from CMV reactivation and persistency.Human leuKocyte antigen (HLA)-tetramers were used for CMV-specific CD8+ cell quantitation by Flow cytometry in twenty post-allogeneic SCT patients.Nine patients (45%) developed rapid recovery of CMV-specific CD8+ cells, among them; 7 patients (78%) had no CMV reactivation in the first 95 days post-transplant. Five patients had developed persistent CMV viremia; all of them had not developed CMV-specific CD8+ recovery till day 95 post-transplant. Patients with persistent CMV viremia had a statistically significant lower means of CMV-specific CD8+ percent and absolute count compared to those without persistent viremia (p = .001, .015), respectively.The incidence of CMV reactivation and persistency was higher among patients with delayed CMV-specific CD8+ reconstitution in the first 95 days post-transplant.CMV-specific CD8+ cells can help in categorizing patients into risk groups: (early recovery/low risk) and (delayed recovery/increased risk), this tool may guide clinicians in the selection of patients who may profit from prophylactic antiviral therapy and frequent viral monitoring.

Cytomegalovirus (CMV) infection remains a major cause of morbidity/mortality after allogeneic hematopoietic cell transplantation (HCT). Preemptive antiviral therapy is associated with drug-induced toxicities, and prophylactic therapy with letermovir is associated with late reactivations and delayed antiviral immune reconstitution. Therefore, substituting antivirals with a vaccine that harnesses the native immune response to CMV may improve outcomes for HCT recipients. Our group has developed a peptide vaccine, CMVPepvax, composed of an HLA-A*0201 restricted pp65 495-503 CD8 T cell epitope, covalently linked to a universal tetanus T helper epitope and co-administered with PF-03512676 adjuvant. CMV PepVax was safe and immunogenic in a healthy volunteer study (La Rosa et al. PMID: 22402037;) and a phase Ib HCT recipient trial (Nakamura, et al. PMID: 26853648) with the latter demonstrating a promising sign of efficacy in reducing CMV viremia. In this double blind, placebo-controlled, randomized phase 2 trial (NCT02396134), HCT recipients were enrolled at four USA transplant centers. Eligible patients were CMV seropositive, HLA A*0201-positive, 18-75 years, receiving HCT from a matched related/unrelated donor. T-cell depleting agents (i.e. ATG) or recipients of ex-vivo T-cell-depleted grafts were excluded. Prophylactic antiviral therapy was not allowed. Patients were enrolled prior to day 0 of HCT and reassessed on day +28 for eligibility and randomization to the vaccine (VA) or placebo arm (PA), stratified by donor CMV serostatus. PepVax was administered subcutaneously on days +28 and +56 post-HCT. The primary endpoint of the trial was CMV viremia ≥1250 IU/m or CMV disease through 100 days post-HCT. A total of 96 patients were planned to be randomized at 1:1 ratio, providing 90% power to detect a reduction of viremia from 40% to 15%. CMVpp65-specific immune reconstitution was monitored by measuring levels of CD8 T cells binding to MHC class I pp65 495-503 and HIVgag 77-85 (as control) multimers (Immudex Dextramers), as well as CD28 and CD45 memory markers (BD Biosciences). The intensity of the fluorescent labels was measured using a Gallios flow cytometer with Kaluza software (Beckman Coulter). Enrollment started in June 2015 but was stopped in November 2017 when a planned interim analysis suggested futility for the primary efficacy endpoint. By that time, 76 subjects had been consented, of whom 61 met the day 28 eligibility criteria and were randomized to the VA (n=32) or PA (n=29). The unblinded data were released when the planned one-year follow up was completed for these 61 subjects. The two groups were overall balanced in their demographics and HCT characteristics. There was no difference in the primary endpoint of CMV reactivation/disease between VA (25.1%) and PA (13.8%, p=0.15). The incidence of preemptive therapy was similar between the two arms. PepVax was well tolerated with no increase in adverse events. Transplant outcomes were also similar between the two groups with regards to 1-year overall survival, relapse-free survival, non-relapse mortality, relapse, and acute GVHD. In subjects in VA who reached the primary endpoint (n=8), CMV viremia occurred at a median of 20 days (interquartile range: 15-23 days; range, 0-48) after the first vaccine, suggesting that there was insufficient time for the vaccine-induced T cell expansion. Significantly higher levels of long lasting pp65-specific T cells with effector memory phenotype were measured in non viremic participants in the VA compared to those in the PA; this effect was driven by differences observed late after vaccination (p = 0.004 by GEE analysis; Figure, panel A). In patients who controlled viremia, robust expansion of functional pp65-specific CD8 T cells was observed following PepVax injections (Figure, panels B-C). Our results confirm safety and immunogenicity of PepVax in CMV seropositive HCT recipients. However, the trial failed to demonstrate a clinical efficacy of PepVax in reducing CMV viremia/disease despite favorable CD8 T cell responses. Early CMV reactivation/disease detected before receipt of the second vaccine may have reduced the ability of PepVax to elicit a protective T cell response. Transfer of vaccine-induced immunity through donor CMV immunization combined with recipient booster immunization may overcome this issue and lead to faster immune reconstitution post-HCT. Figure 1 Figure 1. Disclosures Hill: Amplyx: Consultancy; OptumHealth: Consultancy; CRISPR therapeutics: Consultancy; Gilead: Consultancy, Research Funding; Allogene therapeutics: Consultancy; Octapharma: Consultancy; Allovir: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; CLS Behring: Consultancy; Karius: Research Funding. Al Malki: Hansa Biopharma: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; Neximmune: Consultancy; Rigel Pharma: Consultancy; CareDx: Consultancy. Pullarkat: Amgen, Dova, and Novartis: Consultancy, Honoraria; AbbVie, Amgen, Genentech, Jazz Pharmaceuticals, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees. Aribi: Seagen: Consultancy. Devine: Tmunity: Current Employment, Research Funding; Magenta Therapeutics: Current Employment, Research Funding; Sanofi: Consultancy, Research Funding; Johnsonand Johnson: Consultancy, Research Funding; Orca Bio: Consultancy, Research Funding; Be the Match: Current Employment; Vor Bio: Research Funding; Kiadis: Consultancy, Research Funding. Verneris: Novartis: Other: advisory board; jazz: Other: advisory board; Fate Therapeutics: Consultancy. Miller: Fate Therapeutics, Inc: Consultancy, Patents & Royalties, Research Funding; GT Biopharma: Consultancy, Patents & Royalties, Research Funding; Vycellix: Consultancy; ONK Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Magenta: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Wugen: Membership on an entity's Board of Directors or advisory committees. Forman: Allogene: Consultancy; Lixte Biotechnology: Consultancy, Current holder of individual stocks in a privately-held company; Mustang Bio: Consultancy, Current holder of individual stocks in a privately-held company. Diamond: Pfizer Inc: Other; Helocyte Inc: Membership on an entity's Board of Directors or advisory committees, Other, Patents & Royalties.

Background: Cytomegalovirus (CMV) is a common cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT) despite major advances in diagnostic techniques and antiviral prophylactic strategies. The relative impacts of donor/recipient CMV serologic status, disease-specific and transplant-related prognostic factors on the risk of CMV reactivation and survival are undefined. Methods: We studied the outcome of 199 patients (median age, 46 years; range 17-71 years) receiving allogeneic HCT at National University Cancer Institute of Singapore (NCIS) between January 2016 and December 2020. Their hematologic diseases included AML (n=92), ALL (n=46), MDS (n=19), lymphomas (n=19), MPN (n=7) and others (n=16) such as refractory myelomas and aplastic anemias. The conditioning regimens used were either myeloablative (n=80) or reduced intensity conditioning (n=119) prior to an allograft from different donor sources. T-cell depletion (TCD) was used for GVHD prophylaxis in 124 patients; and this included post-transplant cyclophosphamide (PTCy, n=31), ex-vivo T-cell receptor alpha-beta / CD45RA depletion (TCRab/CD45RA) (ex-vivo TCD, n=31) for haploidentical HCT, or thymoglobulin (ATG, n=62) for matched unrelated donor (MUD) HCT. Results: With a median follow-up duration of 15.6 months (range, 0.2-63.6 months), 136 (68.3%) patients had CMV reactivation (median onset, 27.5 days) while 6 (3.0 %) patients developed clinically significant CMV disease, such as colitis, retinitis and encephalitis. The cumulative incidences of CMV reactivation within the first 100 days among the recipients of matched unrelated donor (MUD) (n=60), mismatched related donor or unrelated donor (MMRD/MMUD) (n=60), umbilical cord blood (UCB) (n=18) and matched related donor (MRD) (n=61) HCT were 71.6 %, 61.7 %, 50.0 % and 32.7 %, respectively (p There were no statistically significant differences in overall survival (OS, p=0.830) and disease-free survival (DFS, p=0.983) at 5 years between CMV-seropositive (D+/R+ or D-/R+, n=181) and CMV-seronegative recipients (D-/R- or D+/R-, n=18). There were also no significant differences in the cumulative incidences of CMV reactivation within 100 days (p=0.879), CMV end-organ disease (p=0.522) and non-relapse mortality (NRM, p=0.202), respectively. HCT-CI score of ≥1 (p=0.005) and the use of reduced intensity conditioning regimen (p The secondary objective of this study was to determine the risk factors associated with CMV reactivation within the first 100 days post-transplant. There was no statistically significant impact of the donor or recipient CMV serostatus (p=0.790) on the risk of CMV reactivation. In multivariable analysis, the use of any T-cell depletion (p Conclusions: Our study concluded that CMV serologic status did not affect the incidence of CMV reactivation, NRM, OS and DFS in patients undergoing allogeneic HCT. The use of PTCy and ATG for GVHD prophylaxis, remains the most important risk factor for CMV reactivation in the era of pre-emptive therapy and hence, the need for aggressive prevention strategies in this vulnerable group of patients. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Background: Cytomegalovirus (CMV) is a major cause of morbidity in allogeneic hematopoietic stem cell transplant (HSCT) patients. Marty et al. 2017 showed that letermovir is effective in preventing CMV reactivation in high-risk HSCT patients, though only 16% were haplo-identical. Recently, Karam et al. 2019 showed decreased rates of CMV reactivation in haplo-identical HSCT using letermovir in unselected high-risk patients. The effects of letermovir on other transplant-related outcomes including overall survival (OS), relapse free survival (RFS), and Graft-versus-host-disease (GVHD)-free-/relapse-free survival (GRFS), however, are not as well-known. With the increased use of post-transplant cyclophosphamide (PTCy) as GVHD prophylaxis in all transplant types, letermovir use may need to be broadened as those that are T-cell depleted are also at increased risk of CMV reactivation. Methods: We retrospectively analyzed adult patients at USC Norris Cancer Hospital (age ≥ 18) who received allo-HSCT from 2018 to 2020. Recipients who were CMV positive, received T-cell depleting therapies such as PTCy for GVHD prophylaxis and/or ATG in the conditioning regimen, and those who fulfilled the criteria in Marty et al. 2017 were categorized as high-risk. Patients were considered to have CMV reactivation if they had clinically significant serum CMV viremia or organ involvement by day+100. Letermovir was initiated on day+21 for high-risk patients. The primary end-point assessed was day+100 CMV reactivation. Secondary end-points included 1-year OS, 1-year RFS, 1-year transplant-related mortality (TRM), and 1-year GRFS, defined as grade 3-4 acute GVHD, systemic therapy-requiring chronic GVHD, relapse, or death in the 1-year post-HSCT period. Results: A total of 116 adult HSCT recipients were reviewed. 51% were male and 49% were female. The donor sources comprised of 27% match related, 28% match-unrelated, and 49% haplo-identical. Most common diseases included AML (38%), ALL (38%) and MDS (8%). 64% received myeloablative conditioning regimens while 36% received reduced intensity regimens. Furthermore, 92% of patients received peripheral blood with 8% receiving bone marrow. 70% of patients at time of transplant were in CR1 or had stable disease. 61% of patients received letermovir prophylaxis (n=71), all high-risk, and 39% did not (n=45). 13 high-risk patients did not receive letermovir due to insurance limitations and were included in the non-letermovir group. 85% (n =60) received T-cell depleting therapies in the letermovir group compared to 51% (n=23). 90% (n=64) were CMV positive in the letermovir group and 64% (n= 29) were positive in the non-letermovir group. Both groups were similar in regard to the incidence of GVHD. The only factors significantly associated with CMV reactivation were haplo-HSCT, CMV recipient positivity, use of PTCy as GVHD prophylaxis and/or ATG in conditioning regimen, risk status, and GVHD (p = 0.054, p = .017, p = 0.003, p = 0.050, and p = 0.024 respectively). In a subset analysis of all high-risk patients, CMV reactivation was 32% in the letermovir group and 69% in the non-letermovir group (p = 0.03). All other factors were not significantly associated with outcomes. CMV reactivation in the letermovir group was (32%) compared to the non-letermovir group (29%). 1-year OS, 1-year TRM, 1-year RFS, and 1-year GRFS were 85%, 13.2%, 87%, and 60% respectively in the letermovir group compared with 88%, 10%, 90%, and 56% in the non-letermovir group, though not statistically significant. Discussion: Our study confirms improved CMV reactivation outcomes with use of letermovir in high-risk patients. Furthermore, all end-points were similar between both groups, despite increased usage of myeloablative conditioning overall and more high-risk patients in the letermovir group, indicating improved 1-year OS, TRM, and GRFS compared with historical outcomes. Although the primary and secondary end-points were not statistically significant, it may be clinically meaningful, as our center has demonstrated similar outcomes amongst those who were high-risk and received letermovir and those who were low-risk and did not. This suggests broadened use of letermovir may be needed in the prevention of CMV reactivation and the improvement in overall outcomes. Further studies using letermovir in low risk patients may be necessary to investigate improved outcomes in the allo-HSCT setting. Disclosures Yaghmour: Jazz: Consultancy, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Consultancy, Speakers Bureau; Alexion: Consultancy, Speakers Bureau.

Report from the 43rd Annual Meeting of the European Society for Blood & Marrow Transplantation 2017, 26–29 March 2017, Marseille, France Cytomegalovirus (CMV) reactivation is a potentially life-threatening complication in immunocompromised recipients of hematopoietic cell transplantation (HCT). Its management was therefore a key topic for over 5000 delegates from 85 countries attending the 43rd Annual Meeting of the European Society for Blood & Marrow Transplantation 2017. The currently available anti-CMV armamentarium is seldom used to prevent CMV reactivation due to the associated myelosuppression and renal toxicity. Following HCT, CMV reactivation is generally managed pre-emptively using sensitive assays for early detection of viral DNA (and to a lesser extent antigenemia) and, where necessary, treatment with antiviral drugs with the aim of preventing CMV disease. However, any degree of CMV reactivation increases the risk of mortality, and novel antiviral therapies may offer the possibility of prophylaxis to prevent CMV reactivation and improve survival after HCT.

Background Children receiving an allogeneic hematopoietic cell transplant (HCT) are at risk for cytomegalovirus (CMV) infection in the post-transplant period, necessitating routine surveillance for CMV. Some patients will not have CMV detected while others will have intermittent or persistent CMV detection. Prior analyses assessing the association of CMV infection on hospitalization in the post-transplant period have been limited by methods that did not consider the time-varying nature of the exposure (CMV reactivation) and its confounders or aim to obtain causal effect estimates. We aimed to assess the causal effect of CMV reactivation on hospitalization using a causal modeling approach. The Effect of CMV Infection on Hospitalization Using Generalized Estimating Equations and Marginal Structural Models Methods A cohort of allogeneic HCT patients transplanted at Children’s Hospital of Philadelphia January 2004–April 2017 was assembled and followed for 100 days after transplant. Eligible patients included those under CMV surveillance, defined as having ≥2 CMV whole blood polymerase chain reaction tests in the first month after HCT. All information was abstracted from medical charts. The association of CMV reactivation on the rate of hospitalization was estimated using traditional generalized estimating equations and repeated using a marginal structural model that accounted for time-varying exposure, confounders and non-random drop-out and obtained effects with causal interpretations. Results The study cohort included 340 pediatric allogeneic HCT recipients under CMV surveillance testing. 46.5% were female and the median age was 9 (range: 0 to 26). The CMV infection rate was 33.9%, with a median time to CMV detection of 23.5 days (range: 4-100). CMV infection was common in Donor+/Recipient+ (58.9%) and Donor-/Recipient+ (34.6%) patients. A traditional model estimates an additional week of CMV infection was associated with a 22% increase in average weekly hospitalization (Incidence rate ratio: 1.22, 95%: 1.12 -1.34). A marginal structure model estimates an additional week of CMV infection is associated with 3% increase in average weekly hospitalization incidence (Incidence rate ratio: 1.03, 95%: 0.91-1.16). Conclusion Our research showed the effect of CMV on hospitalization diminished after properly considering the time-varying nature of the CMV infection status and its confounders. Disclosures Brian T. Fisher, DO, MPH, MSCE, Astellas (Advisor or Review Panel member)Merck (Grant/Research Support)Pfizer (Grant/Research Support)

Background CMV reactivation is associated with significant morbidity and mortality in allo-HCT recipients and could be a resource intensive condition to manage. Limited data are available on the economic ramification of CMV reactivation in allo-HCT. Therefore, we aimed to examine healthcare cost and length of hospital stay (LOS) among allo-HCT recipients treated for CMV infection. Methods We performed a retrospective cohort study that included 56 consecutive allo-HCT recipients who were diagnosed with CMV infection within 100 days post-transplant and admitted to two medical centers, University of Texas MD Anderson Cancer Center and University of Chicago, Department of Infectious Disease between January 2016 and December 2017. CMV-related hospitalization was determined as an inpatient admission with or for CMV reactivation within 100 days post-transplant. Data were limited to only the first CMV-related hospitalization. Descriptive statistics were reported on patient characteristics, first CMV-related hospitalization and costs. Results Most patients were 40 years or older (64%), female (55%), Caucasian (66%), CMV seropositive recipients (87%), received a matched unrelated donor HCT (49%) and had a myeloablative or reduced intensity conditioning regimen (65%) (Figure 1). The median duration of CMV episode was 40 days. Seventy-one percent of the patients were treated with foscarnet for CMV infection. Acute kidney injury was the most frequent CMV treatment-related complication (67%) followed by myelosuppression (55%) and end-stage renal disease (36%). Of 56 encounters, 16% required admission to intensive care unit with a median duration of 9 days. The median length of stay for hospitalization was 23 days and healthcare cost for CMV-related hospitalization was $71,840. The median hospitalization cost and LOS varied by reason for hospitalizations, type of anti-CMV therapy and treatment-related complications (Figure 2). Figure 1. Baseline characteristics, CMV episodes, outcomes, and cost. Figure 2. CMV Outcomes among allo-HCT recipients Conclusion Our study showed even a single episode of CMV-related hospitalization led to significant resource use and hospitalization costs. This study highlights the need for interventions to prevent of CMV-related hospitalization, thereby reducing associated cost and resource use. Disclosures Kathleen Mullane, DO, Pharm D, FIDSA, FAST, MERCK (Advisor or Review Panel member, Research Grant or Support, Speaker’s Bureau) Ella Ariza Heredia, MD, Merck Sharp & Dohme (Grant/Research Support)Oxford Immunotec (Grant/Research Support) Yuexin Tang, PhD, Merck and Co., Inc. (Employee) Amit D. Raval, PhD, Merck and Co., Inc (Employee) Roy F. Chemaly, MD, MPH, FACP, FIDSA, Chimerix (Consultant, Research Grant or Support)Clinigen (Consultant)Merck (Consultant, Research Grant or Support)Novartis (Research Grant or Support)Oxford Immunotec (Consultant, Research Grant or Support)Shire/Takeda (Research Grant or Support)Viracor (Research Grant or Support)

Introduction: Vertical transmission of Cytomegalovirus (CMV), resulting in congenital CMV (cCMV) infection could have disabling and potentially fatal effects on the foetus or neonate. Although primary infection probably has a higher risk of leading to cCMV, in highly seropositive populations, a significant risk of vertical transmission is thought to be due to CMV reactivation and or reinfection during pregnancy. In this narrative review, we summarise the prevalence of CMV infection and associated risk factors among pregnant African women, in a setting where primary CMV infection usually occurs during infancy. Methodology: A systematic search of literature published between January 2000 and January 2019, retrieved on five bibliographic databases was performed. Search for relevant articles was performed using the following keywords: cytomegalovirus, CMV, infection, antenatal infections, pregnancy, pregnant women, gravidity, developing countries and Africa, with appropriate qualifiers such as OR, AND. Results: Systematic searching retrieved 11 relevant original research papers. Prevalence of anti-CMV IgG and IgM antibodies ranged from 60-100% and 0-15.5%, respectively. Prevalence of CMV DNA ranged from 0-29%, depending on the specimen used. However, there was no geographic trend for CMV seroprevalence or CMV DNA prevalence across the African continent. Overall, a substantial percentage of women of reproductive-age were CMV seronegative and at risk of primary infection. Associations of sociodemographic factors with CMV infection were inconsistent across all reviewed studies. Conclusions: The limited data and inconsistency of findings from the few studies carried out in Africa calls for prospective studies comparing prevalence and outcomes of cCMV in infants born to women with both primary and reactivated CMV in Africa.

Introduction: Cytomegalovirus (CMV) reactivation occurs in seronegative patients after solid organ transplantation (SOT) particularly from seropositive donors and can be lethal. Generation of CMV-specific T cells helps to prevent CMV reactivation. Therefore, we initiated a clinical phase I CMVpp65 peptide vaccination trial for seronegative end-stage renal disease patients waiting for kidney transplantation. Methods: The highly immunogenic nonamer peptide NLVPMVATV derived from CMV phosphoprotein 65(CMVpp65) in a water-in-oil emulsion (Montanide™) plus imiquimod (Aldara™) as an adjuvant was administered subcutaneously four times biweekly. Clinical course as well as immunological responses were monitored using IFN-γ ELISpot assays and flow cytometry for CMV-specific CD8+ T cells. Results: Peptide vaccination was well tolerated, and no drug-related serious adverse events were detected except for Grade I–II local skin reactions. Five of the 10 patients (50%) mounted any immune response (responders) and 40% of the patients presented CMV-specific CD8+ T cell responses elicited by these prophylactic vaccinations. No responders experienced CMV reactivation in the 18 months post-transplantation, while all non-responders reactivated. Conclusion: CMVpp65 peptide vaccination was safe, well tolerated, and clinically encouraging in seronegative end-stage renal disease patients waiting for kidney transplantation. Further studies with larger patient cohorts are planned.

A previously well and immunocompetent 64-year-old woman presented with fever of unknown origin and acute hepatitis. Besides headache and nausea, she had no other symptoms. Her clinical examination was unremarkable with no clear focus of infection. She was thoroughly investigated and her biochemical profile suggested a viral or autoimmune aetiology. Multiple imaging modalities gave no further insight. Her serology and subsequent nucleic acid amplification indicated reactivation of latent cytomegalovirus (CMV). Her symptoms resolved with supportive care and no anti-viral therapy was needed. This case report highlights CMV reactivation leading to acute hepatitis in a well, immunocompetent patient.

Allogeneic hematopoietic cell transplantation (HCT) may be curative for patients with marrow and immune disorders, but graft-vs-host-disease (aGVHD) and infections cause significant morbidity and non-relapse mortality. We have conducted a multicenter, double blind, placebo-controlled phase II trial of costimulation blockade with abatacept (Aba) combined with standard GVHD prophylaxis with a calcineurin inhibitor and methotrexate (CNI + MTX) following HLA matched unrelated donor transplant (n=142). In order to assess the effects of Aba on immune reconstitution, and to assess whether this reconstitution is influenced during CMV reactivation, we longitudinally evaluated post-transplant whole blood samples with multiparameter flow cytometry using markers for CD3, CD4, CD8, CD197 and CD45RA to measure reconstitution of CD4 and CD8 T cell populations and their respective memory subsets over time. Results: We observe that post-transplant CMV reactivation induces a marked expansion of CD8 effector memory (EM) cells, which is similar in magnitude for Aba vs placebo patients. We found that development of moderate (gr 2-4) or severe (gr 3-4) GVHD was not associated with an increased frequency of CMV reactivation, but patients with moderate GVHD showed a blunted expansion of CD8 EM cells compared to those without GVHD, and CD8 EM expansion was essentially absent among CMV reactivating patients with severe aGVHD. Clinical correlates will be presented. Conclusions: Our results suggest that adding abatacept to CNI/MTX does not materially affect reconstitution of T cell immunity in the presence or absence of CMV reactivation, but aGVHD remains a major driver of compromised immune recovery after HCT. Disclosures Watkins: Bristol Myers Squibb: Research Funding. Qayed:Mesoblast: Consultancy; Novartis: Consultancy. Horan:Bristol Myers Squib: Honoraria, Research Funding. Kean:gilead: Research Funding; bluebird bio: Research Funding; fortyseven: Consultancy; magenta: Research Funding; regeneron: Research Funding; hifibio: Consultancy; kymab: Consultancy; Bristol Meyers Squibb: Research Funding; novartis: Consultancy. Langston:Kadmon Corporation: Research Funding; Bristol Myers Squib: Research Funding; Incyte: Research Funding; Chimerix: Research Funding; Takeda: Research Funding; Astellas Pharmaceuticals: Research Funding; Jazz Pharmaceuticals: Research Funding.

7541 Background: Cytomegalovirus seropositive (CMV+) recipients of CMV seronegative (CMV-) hematopoietic cell allografts are at the highest risk for CMV reactivation. Inspired by the recently described effect of antibiotic (abx)-induced dysbiosis on anti-viral immunity, we retrospectively evaluated whether antibacterial abx exposures influence the risk of CMV reactivation after CMV- to CMV+ cord blood (CB) or matched sibling donor (MSD) transplantation, the serologic setting with highest risk of CMV reactivation. Methods: We identified 213 eligible patients (pts; 146 CB, 67 MSD, mean age 50, range 18-73). Exposures to fluoroquinolones (FQN), 3rd or higher generation cephalosporins (CPN3+), intravenous vancomycin (Vanc), piperacillin-tazobactam (Pip-Tazo), carbapenems, and metronidazole/clindamycin (Metro/Clinda) from day (D) -7 to D +14 (binary variables) or until CMV reactivation (or D +100, whichever occurred first; time-varying variables) were included in multivariable Fine-Gray regression models with competing risk for non-CMV death to estimate the risk of CMV reactivation by D +100. Other pre-defined covariates were ATG use during conditioning, anti-CMV abx exposure for other viruses, and acute GVHD. Results: 91% of pts received FQN, 67% CPN3+, 56% Vanc, 21% Pip-Tazo, 22% carbapenems, and 28% Metro/Clinda until D +14. These numbers increased to 94%, 81%, 76%, 31%, 38%, and 39% by D +100 (or CMV reactivation), respectively. 83 pts (39%: 66 CB, 17 MSD) had CMV reactivation by D +100. Vanc exposure by D +14 almost doubled the risk of CMV reactivation (HR 1.96, 95%CI 1.11-3.46, P = 0.02). With abx exposures up to D +100 modeled as time-varying covariates, Vanc exposure predicted a higher risk for CMV reactivation (HR 1.86, 95%CI 0.99-3.52, P = 0.06). The table below summarizes the results, excluding non-abx covariates for brevity. Conclusions: Our results suggest that vancomycin-sensitive bacteria may protect against CMV reactivation. Identifying the specific taxa and their location (intestinal vs. extraintestinal) requires more research. Microbiota considerations and abx exposure patterns can help personalize CMV prophylaxis. [Table: see text]

e18062 Background: Cytomegalovirus (CMV) is a common infection associated with increased inflammation (c-reactive protein (CRP) upon reactivation during immunosuppression. CMV infection has been associated with a subset of NK cells (adaptive) that are long-lived, have enhanced cytotoxicity, and thought to contribute to cancer control. Previous evaluation of a retrospective study showed CMV+CRP+ patients had significantly worse RFS and OS compared to CMV+ CRP− patients who had the longest OS. These findings suggest CMV may be immunomodulatory and, without immunosuppressive effects of inflammation, may be protective. We are further evaluating for the presence of adaptive NK cells in the patients to evaluate if these populations of cells are drivers for the changes in outcomes. Methods: Serum and ascites (22 samples each) collected in a prospective study at the time of surgery for HGSOC were evaluated for CMV and inflammation. CMV status and systemic inflammation were measured by immunoassay for CMV immunoglobulin G (IgG), dPCR for CMV DNA and C-reactive protein (CRP). Samples were categorized as reactive or non-reactive for CMV and positive or negative for CRP (≤10, > 10 mg/L). Adaptive NK cell percentages were analyzed using GraphPad Prims 8 and p-values ≤ 0.05 were considered statistically significant. Proteomic techniques to quantify adaptive NK cells, differences in NK cell maturation and cytotoxicity are in process for an additional 80 samples. Results: CMV reactive patients showed increased percentages of adaptive NK cells (NKG2C+CD57+) in the blood and peritoneal cavity compared to CMV negative patients. There is a trend in the presence of adaptive NK cells in patient samples that are CMV reactive and CRP positive compared to CMV nonreactive and CRP positive. Conclusions: Preliminary analysis shows a trend in presence of adaptive NK cells in both the blood and peritoneal cavity of these patients but analysis is ongoing.

Nepal is a low income country in Asia with 38M inhabitants. In August 2016 a Blood & Marrow Transplant (BMT) Center was opened at Civil Service Hospital in Kathmandu initially performing autologous HSCT and since August 2017 also allogeneic HSCT. University of Illinois at Chicago (UIC) has been collaborating with Civil Hospital since 2012 to provide training for staff, advice on infrastructure and stem cell lab operations, clinical protocols, and implementation of a quality program. Until September 2019, a total of 46 HSCT were performed for patients (29 males and 17 females) with hematologic malignancies or aplastic anemia. Of 46 transplants, 26 were autologous (median age: 48 years, range: 15-63) and 20 allogeneic HSCT (median age: 20 years, range: 9-38), including 15 from a matched related (MRD) and 5 from a haploidentical donor. The median time of follow-up for autologous and allogeneic HSCT was 24 mo (4-37) and 6.5 mo (3.5-18), respectively. In all transplants the stem cell source was mobilized peripheral blood stem cells (PBSC). In allogeneic HSCT, all the patients received GVHD prophylaxis including post-transplant cyclophosphamide (PTCY) regardless of type of donor. Overall D100 mortality was 7%. At the last follow-up, 24 of 26 (92%) patients who received an autologous HSCT and 13 of 19 (68%) who received an allogeneic HSCT were alive, while 1 patient was lost at follow-up at d140. CMV reactivation was detected in 45% of patients. Acute GVHD grade 2 was observed in 5% of patients and no grade 3 or 4 was detected. Chronic GVHD (mouth) was observed in 3% of patients. Access to transplant was only possible to patients who could: travel to the hospital, afford the cost of transplant and lodging, and have a caregiver. The average distance from home to hospital was 296 km (184 miles) and family members and patients after discharge stayed mostly at a hotel close to the hospital. In all 46 cases, the caregiver assisting the patient either had to stop working or, in 3 cases of minors In conclusion, the collaboration between UIC and Civil Service Hospital in Kathmandu has been successful in building capacity for the establishment of the first BMT program in Nepal. Socio-economic determinants affecting access to HSCT such as financial costs, availability of a caregiver and transportation from long distance locations remain often a challenge for BMT in a low income country.

Cytomegalovirus (CMV) reactivation is one of the most common infections affecting allogeneic hematopoietic cell transplant recipients. Although available anti-CMV therapies have been evaluated for the prevention of CMV reactivation, their toxicity profile makes them unfavorable for use as primary prophylaxis; thus, they are routinely reserved for the treatment of CMV viremia or CMV end-organ disease. Pre-emptive CMV monitoring strategies have been widely accepted, and although they have been helpful in early detection, they have not affected the overall morbidity and mortality associated with CMV. Letermovir is a novel agent that was approved for primary prophylaxis in CMV-seropositive adult allogeneic hematopoietic cell transplant recipients. This review focuses on letermovir’s novel mechanism; clinical trials supporting its United States Food and Drug Administration (FDA) approval and subsequent follow-up analyses; clinical considerations, with an emphasis on pharmacology; and lessons learned from solid organ transplant recipients, as well as potential future directions.

Background Cytomegalovirus (CMV) is a major source of morbidity and mortality after hematopoietic cell transplantation (HCT). A recent adult trial comparing letermovir to placebo, found this agent to be efficacious in preventing CMV reactivation with limited toxicity. Additional investigation of letermovir in pediatric HCT recipients is needed. To inform the feasibility of a pediatric trial, we surveyed bone marrow transplant (BMT) centers registered with the Children’s Oncology Group (COG) regarding their CMV management practices and interest in a pediatric trial for CMV prevention. Methods A brief 6-item questionnaire was created using REDCap™ and distributed by email to all COG-approved BMT Centers. The initial email request was sent on March 26, 2018 to the BMT physician representative listed in the COG member roster. A follow-up request was sent on April 2, 2018. The questionnaire requested information about CMV prophylaxis strategies, including antiviral agent(s) employed, and interest in a pediatric trial of CMV prophylaxis. Results The questionnaire was emailed to 89 BMT centers and was completed at 57 (64%). Of these, 23 (40%) reported giving prophylaxis to all or a subset of allogeneic/haploidentical HCT recipients. The most common indication for CMV prophylaxis (21/23) was a CMV recipient-positive, donor-negative allogeneic/haploidentical HCT recipient. Two centers provided prophylaxis to all cord blood recipients regardless of CMV status. Among these 23 prophylaxis centers, there were 10 different reported prophylaxis regimens. Fifty-one (89%) respondents confirmed an interest in a randomized trial to assess the efficacy of letermovir prophylaxis against CMV reactivation. The preferred comparator for such a trial was placebo/nothing (55%) followed by high dose acyclovir (24%). Conclusion A significant proportion (40%) of pediatric BMT centers in the United States administer CMV prophylaxis to at least a subset of their HCT recipients. The variation in prophylaxis regimens highlights the lack of comparative effectiveness data to guide clinical decisions. Nearly all centers, regardless of whether they currently provide prophylaxis, reported an interest in a trial assessing the utility of letermovir prophylaxis in children. Disclosures B. T. Fisher, Merck: Grant Investigator, Grant recipient and Research grant. C. L. K. Boge, Merck: Grant Investigator, Research grant.

Cytomegalovirus (CMV) is a member of the herpesviridae family and remains latent in the host cells after primary infection. The virus reactivates in the immunosuppressed host and is a leading cause of morbidity following allogeneic hematopoietic stem cell transplant (allo-HSCT). Natural killer (NK) cells provide the first-line defence against viruses and a subset of NK cells expressing NKG2C have been shown to play a role in the immune surveillance of human CMV. Deletion of the NKG2C gene has been reported as a risk factor for viral infections including CMV and HIV, but current data on the influence of NKG2C gene-copy number variations in the donor graft on the risk of CMV reactivation after allo-HSCT is limited. Following cord blood transplantation (CBT), where the T-cell compartment is functionally naïve, the NKG2C genotype may have an even more pronounced impact on the risk of CMV reactivation. Therefore, we studied NKG2C copy number in the donor graft and the risk of CMV reactivation after double umbilical cord blood transplantation (DUCBT) in 100 CMV seropositive DUCBT recipients and their corresponding cord blood grafts (n=200). The gene encoding NKG2C is present at different copy numbers in the genomes of different individuals, with possible genotypes including 2 copies (wt/wt), 1 copy due to heterozygous deletion (wt/del) or 0 copies due to homozygous deletion (del/del). Among the donor CB units, approximately 2/3 had both copies of the gene (wt/wt), 1/3 had only one copy (wt/del) and only a minority of units had 0 copies with both alleles deleted (del/del). In the setting of DUCBT, the combined graft may contain 0 to 4 functional copies of NKG2C gene. In our cohort, patients whose combined grafts contained only 1 or 2 NKG2C gene copies had a significantly higher probability of CMV reactivation than patients whose combined grafts had 3 or 4 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the 4 groups was 100%, 92.9%, 60.5% and 55.9% respectively (p=0.005). No patient received a graft with zero gene copies. For the rest of the analysis we divided the patients into two groups, namely the 84 patients who received a combined graft with 3 or 4 NKG2C copies and the 16 patients who received two units with 1 or 2 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the two groups was 58.4% and 93.7% respectively (p=0.0003). In a multivariate analysis, receiving a combined graft with low NKG2C copy number (1 or 2 copies) (HR=2.72, CI=1.59-4.64; p Disclosures Oran: ASTEX: Research Funding; AROG pharmaceuticals: Research Funding; Celgene: Consultancy, Research Funding. Champlin:Sanofi: Research Funding; Otsuka: Research Funding. Shpall:Affirmed GmbH: Research Funding.

BACKGROUND: Cytomegalovirus (CMV) infections in hematopoietic cell transplant (HCT) recipients cause substantial morbidity and mortality. CMV cell-mediated immunity (CMV-CMI) can be determined by levels of interferon gamma (IFN-γ) production using an enzyme-linked immunospot (ELISPOT) CMV assay (T-SPOT.CMV assay). In this study, we evaluated the ability of this assay to predict the outcome of low-level CMV reactivation in HCT recipients. METHODS: We followed 55 HCT recipients with low-level CMV reactivation up to 8 weeks from enrollment. Progression to clinically significant CMV infection (CS-CMVi) was defined as a CMV load >1000 IU/mL or > 500 IU/mL in patients receiving matched related/autologous or matched unrelated transplants, respectively, and initiation of antiviral treatment. RESULTS: Progression to CS-CMVi occurred in 31 (56%) of the HCT recipients. Spot counts of CMV-specific pp65 and IE1 antigens were significantly lower in patients who had CS-CMVi than in patients who did not. On multivariate analysis, the ELISPOT CMV responses and steroids use were the only predictors of progression to CS-CMVi. CONCLUSIONS: A strong association between low CMV-CMI and progression to CS-CMVi was observed in HCT recipients. The implementation of serial monitoring of CMV-CMI may identify patients at risk of progression to CS-CMVi that require antiviral therapy.

Although it has been recommended to perform sigmoidoscopy to screen for cytomegalovirus (CMV) reactivation in acute severe colitis, the frequency of CMV reactivation in children with inflammatory bowel disease (IBD) is unknown. The aim of this study was to determine the frequency and management of CMV detection in colonic mucosa of children with IBD.In a retrospective study, consecutive IBD patients,17 years old, with moderate to severe colitis who had sigmoid biopsy specimens evaluated for CMV by hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), and polymerase chain reaction (PCR) were included.A total of 90 sigmoid biopsies were collected from 67 patient encounters from 58 patients with colitis: 61 patient encounters (91%) with UC/IBD-U including biopsy samples from colectomy specimens of eight patients who had colectomy during the study period. Medication exposure included corticosteroids for 40 (69%) patients, and immunosuppressive agents for 31 (53.4%) patients. Four of 61 patient encounters (6.6%) with UC/IBD-U, two with corticosteroid refractory disease, had positive biopsies for CMV by PCR but negative HE and IHC. They responded to escalated medical therapy, without needing anti-viral therapy, and none required colectomy over a median duration of follow up of 1.1 year (IQR 1-1.6).CMV presence is uncommon in colonic mucosa of children with IBD. Studies examining the underlying sero-prevalence of CMV and its role of reactivation of colitis are required to determine if the current recommendation for routine sigmoidoscopy to exclude CMV infection in corticosteroid-refractory acute severe colitis is justified.

Background The prognosis of drug-induced hypersensitivity syndrome (DiHS)/drug reaction with eosinophilia and systemic symptoms (DRESS) is highly unpredictable. Severe complications, either related or unrelated to cytomegalovirus (CMV) reactivation, are a highly probable cause of death. Objectives The aim was to establish a scoring system for DiHS/DRESS that can be used to monitor severity, predict prognosis, and stratify the risk of developing CMV disease and complications. Methods A retrospective analysis of 55 patients with DiHS/DRESS was performed. A composite score was created using clinical data. DiHS/DRESS patients were also stratified into 3 groups based on the scores to predict the risk of CMV reactivation and complications. Results This scoring system made it possible to predict CMV disease and complications. Scores ≥4 were associated with the later development of CMV disease and complications, while no patients with scores Limitations This was a single-institution study with a relatively small patient cohort that lacked a validation cohort. Conclusions Our scoring system may be useful for predicting CMV-related complications, and early intervention with anti-CMV agents should be considered in patients with scores ≥4 or with evidence of CMV reactivation.

Background Assays detecting CMV-specific cell-mediated immunity (CMI) may support the current management of CMV infection in solid-organ transplant (SOT) recipients, by allowing a better risk assessment and adjusting antiviral treatment. Objectives The primary endpoint was the performance of two tests measuring CMV-specific interferon-gamma production, both approved for commercial use in clinical settings. Secondarily, we determined a cut-off for the cellular immune response, which protects against CMV reactivation/infection. Study design Thirty kidney transplant (KTx) patients were stratified according to their CMV-IgG status pre-transplantation (Tx) and were divided into two groups: pre-emptive (donor-/recipient+, donor+/recipient+) and prophylaxis (donor+/recipient−). An ELISpot (T-Track-CMV) was performed at month 1 post-Tx (pre-emptive group) and end of prophylaxis and one month thereafter (prophylaxis group). An ELISA (QuantiFERON-CMV) was performed every 2–4 weeks (pre-emptive) or monthly (prophylaxis), in parallel to the CMV viral load (PCR). Results A good positive agreement was obtained between the QuantiFERON-CMV or T-Track-CMV and the CMV-IgG (kappa = 0.839 and 0.824, respectively). A cut-off of 19.5 spot forming units (SFU)/200,000 lymphocytes for the T-Track-CMV IE-1 (AUC = 0.802, sensitivity 45%, specificity 100%) and 495 SFU/200,000 lymphocytes for the T-Track-CMV pp65 (AUC = 0.617, sensitivity 11%, specificity 100%) was defined to assess protection against reactivation. The QuantiFERON-CMV performed modestly (AUC = 0.477, cut-off 85.1 IU/ml). Conclusions The QuantiFERON-CMV and T-Track-CMV enable the functional assessment of CMV-specific CMI in KTx recipients. In combination with CMV viral load monitoring, T-Track-CMV results could stratify patients at risk of CMV reactivation/infection.

The recent increase in zoonotic avian influenza A(H7N9) disease in China is a cause of public health concern. Most of the A(H7N9) viruses previously reported have been of low pathogenicity. We report the fatal case of a patient in China who was infected with an A(H7N9) virus having a polybasic amino acid sequence at its hemagglutinin cleavage site (PEVPKRKRTAR/GL), a sequence suggestive of high pathogenicity in birds. Its neuraminidase also had R292K, an amino acid change known to be associated with neuraminidase inhibitor resistance. Both of these molecular features might have contributed to the patient's adverse clinical outcome. The patient had a history of exposure to sick and dying poultry, and his close contacts had no evidence of A(H7N9) disease, suggesting human-to-human transmission did not occur. Enhanced surveillance is needed to determine whether this highly pathogenic avian influenza A(H7N9) virus will continue to spread.

The anti-CD52 monoclonal antibody alemtuzumab is a highly active treatment for multiple sclerosis (MS) causing rapid depletion of B and T lymphocytes with nadir one month after last infusion. Opportunistic Cytomegalovirus (CMV) infections have been reported in MS patients treated with this drug. We report one patient who developed a CMV reactivation with hepatic involvement three weeks after the first cycle of alemtuzumab. This patient, promptly diagnosed and treated, achieved a complete recovery with valganciclovir. The possibility of this treatable opportunistic infection should be considered by neurologists in febrile patients with hepatic markers alteration after treatment with alemtuzumab.

We previously demonstrated a lower rate of CMV reactivation and disease among seropositive umbilical cord blood transplant (CBT) recipients receiving an intensive prophylaxis strategy consisting of ganciclovir on days -8 to -2 pre-transplant, high-dose valacyclovir post-transplant, and twice-weekly serum CMV PCR testing. We hypothesized that a modified intensive strategy excluding pre-transplant ganciclovir would be similarly effective. We compared the risk of CMV reactivation, occurrence of CMV disease, and duration of anti-CMV therapy by day 100 post-CBT in patients receiving the modified intensive and intensive strategies. Forty patients received the modified intensive strategy, and 43 received the intensive strategy. There was no difference in the hazard for CMV reactivation (HR, 1.1; p = 0.77). No patients developed CMV disease in the modified intensive cohort compared to 2 patients in the intensive cohort ( p = .53). There was no difference in the hazard for early (≤30 days post-CBT; p = .76) or high-level (>1000 IU/ml; p = .37) CMV reactivation. Patients in the modified intensive cohort had marginally higher CMV viral loads and percentages of days of CMV detection and treatment, although the contribution of pre-transplant ganciclovir to these changes is unclear. The overall percentage of treatment days was 32% in both cohorts after accounting for pre-transplant ganciclovir. In conclusion, exclusion of prophylactic ganciclovir before CBT did not impact the risk for CMV reactivation or disease, although CMV kinetics appeared to differ by prevention strategy. Best practices for CMV prevention will need further study as new prophylactic strategies become available.

Aim: Although allogeneic stem cell transplant (alloSCT) remains the only curative option for myelofibrosis, novel therapeutic agents, the application of new prognostic scoring systems and the emergence of molecular genetic analysis have lead to a new management landscape in myelofibrosis. In view of these recent advances, we aimed to review national practice in transplanting myelofibrosis patients and its outcomes. Methods: A retrospective study was conducted using the Australasian Bone Marrow Transplant Registry (ABMTRR) data on patients who underwent alloSCT for myelofibrosis at Australian/New Zealand transplant centres between 2006 and 2017. Participating centres completed an online questionnaire and responses were reviewed centrally by the ABMTRR. Results: 142 patients underwent alloSCT for myelofibrosis, primary (n=94) or secondary (n=48) (Table 1). 52% had HLA-identical sibling donors and 45% had matched unrelated donors (UD). Median follow-up was 51.8 months (range: 3.1-148). Cytogenetic abnormalities were identified in 29% of 120 patients who were tested pretransplant. JAK2 mutation testing was performed in 74% of patients whilst other mutations (CALR, MPL, EZH2, IDH, SRSF2, ASXL1) were rarely tested (1.4-8.4%). Only 4.2% of patients had next generation sequencing. Before transplant, 16% had splenectomy or splenic irradiation and 54 patients (38%) received JAK 1/2 inhibitors (JAKi), of whom 92.5% had Ruxolitinib. Median time to neutrophil engraftment was 20 (range: 10-43) days whereas median platelet recovery time was 28 (range: 13-230) days. 9 patients (6.3%) had primary graft failure and 11 patients (7.7%) had secondary graft failure. 60% had chimerism studies using cytogenetic or molecular techniques at 3 months post transplant; 63% of those assessed achieved complete (≥95%) donor chimerism. CMV reactivation was detected in 32% and 10% had sinusoidal obstruction syndrome. The cumulative incidence of grade II-IV acute GvHD was 21.4% and grade III-IV acute GvHD was 8.7%. The cumulative incidences of limited and extensive chronic GvHD at 5 years were 11.1% and 18.1% respectively. Overall survival (OS) was 67% at 1 year and 57% at 5 years. GvHD free progression free survival was 54% at 1 year and 42% at 5 years (Figure 1). The cumulative incidence of non-relapse mortality (NRM) was 16% at 100 days and 25% at 1 year. In multivariate analysis, use of an UD was a significant independent unfavourable risk factor for OS (HR 2.26, 95%CI 1.17- 4.33, p=0.015) and NRM (HR 3.02, 95%CI 1.36-6.71, p=0.007), while splenic irradiation/splenectomy resulted in shortened neutrophil (HR 1.88, 95%CI 1.00-3.54, p=0.05) and platelet recovery time (HR 2.13, 95%CI 1.12-4.05, p=0.02). Use of UD significantly increased the incidence of grade II-IV acute GvHD in multivariate analysis (HR 5.66, 95%CI 1.99-16.11, p=0.001) whereas use of antithymoglobulin or alemtuzumab significantly reduced it (HR 0.27, 95% CI 0.09-0.79, p=0.017). Neither use of JAKi prior to alloSCT nor presence of JAK2 mutation had a significant impact on OS or NRM. 9 patients underwent a second alloSCT for myelofibrosis and median length of time from the first transplant was 22 (range: 1-132) months. 4 patients were transplanted for disease relapse and 3 patients for graft failure. For the second transplant cohort, NRM at day 100 and 1 year were 11.1% (95% CI, 0.4%-40.6%) and 33.3% (95% CI, 6.6%-64%) respectively, while 1-year and 5-year OS were 66.6% (95% CI, 42%-100%) and 44.4% (95% CI, 21.4%-92.2%). Conclusion: Survival rates in alloSCT for myelofibrosis in this Australasian cohort were comparable to international studies. There is a rise in the numbers of patients treated with JAKi pretransplant (Figure 2). Although this does not appear to have any effect on transplant outcomes, reduced symptom burden associated with increasing use of pre-transplant JAKi may increase the numbers of patients considered eligible for alloSCT. Although splenectomy/splenic irradiation had a positive impact on engraftment, it did not improve the survival outcomes. Our results show a negative influence of UD on OS and NRM, possibly related to an increased incidence of acute GVHD in the UD group. In light of the rise in utilization of alloSCT in the management of myelofibrosis, there is a need for further prospective studies incorporating molecular testing and the new comprehensive clinical-molecular myelofibrosis transplant scoring system. Disclosures Spencer: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Haemalogix: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Secura Bio: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Specialised Therapeutics Australia: Consultancy, Honoraria. Purtill:MSD: Honoraria; Novartis: Honoraria, Other: Travel for speaking and advisory boards; Gilead: Honoraria, Other: Travel for speaking and advisory boards; Janssen: Honoraria. Browett:Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees; Achillion: Research Funding; Beigene: Research Funding. Szer:Sanofi: Honoraria, Other: Travel, Research Funding; Takeda: Honoraria, Other: Travel, Research Funding; Pfizer: Honoraria, Other: Travel, Research Funding; Alexion: Honoraria, Other: Travel, Research Funding; Amgen: Honoraria, Other: Travel, Research Funding; Celgene: Honoraria, Other: Travel, Research Funding; MSD: Honoraria, Other: Travel, Research Funding; Novartis: Honoraria, Other: Travel, Research Funding; Prevail Therapeutics: Honoraria, Other: Travel, Research Funding. Ritchie:Amgen: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy; BMS: Research Funding; Takeda: Research Funding; Beigene: Research Funding; Imago: Research Funding; Novartis: Honoraria; Sanofi: Honoraria. Greenwood:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Gottlieb:Merck: Consultancy; AbbVie: Consultancy; Gilead: Consultancy; Novartis: Consultancy; University of Sydney: Employment; Haemalogix P/L: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Background: Cytomegalovirus (CMV) reactivation still represents a common complication after allogeneic stem cell transplantation and is associated with increased non-relapse mortality (NRM) and reduced overall survival (OS). Patients receiving T cell-replete haploidentical stem cell transplantation (haplo-SCT) with high dose post-transplant cyclophosphamide (PT-Cy) are considered at higher risk of developing CMV reactivation due to their particular immuno-suppressed status. Letermovir was recently shown to significantly reduce the frequency of CMV reactivation in a phase 3 clinical trial. We decided to perform a retrospective analysis among patients treated with haplo-SCT with PT-Cy in order to identify whether every patients should receive CMV prophylaxis with letermovir or it is possible to identify a particular subgroup that may benefit more of prophylactic treatment. Methods: We retrospectively analyzed 513 consecutive patients receiving Haplo-SCT with PT-Cy at our institutions between April 2009 and December 2018. Median age was 56 years old (range 15-77), main diagnosis was represented by acute myeloid leukemia (31%), Hodgkin lymphoma (22%), non-Hodgkin lymphoma (21%) and myelodisplastic syndrome (12%). Donor/recipient CMV serostatus was as follows: neg/neg (G1) 16%, pos/pos (G2) 50%, pos/neg (G3) 12% and neg/pos (G4) 22%. Conditioning regimen was non-myeloablative/reduced intensity in 90% of the cases, graft source was represented by bone marrow for 25% of the patients. Results: With a median follow-up of 35 months, 3-year OS was 57%, 3-year NRM 24% and 3-year graft-versus-host-disease (GVHD)/relapse free survival (GRFS) 43%. 180-days cumulative incidence of grade 2-4 acute GVHD was 23% and 2-year moderate-severe chronic GVHD was 9%. Median day of CMV reactivation was 41 days (range 10-275), 100-days and 1-year cumulative incidence of CMV reactivation was 43% and 48%, respectively. Cumulative incidence of CMV reactivation was more common among seropositive recipients: G1 1% vs G2 60% vs G3 32% vs G4 67% (Table I, p Conclusion: Recipient positive CMV serostatus is associated with increased risk of CMV reactivation, increased rate of NRM and worse GRFS. CMV reactivation is associated with increased risk of developing grade 2-4 acute GVHD and higher NRM. We conclude that also in the platform of haplo-SCT with PT-Cy, letermovir prophylaxis should be given not to all patients, but mainly to CMV seropositive recipients, that probably may benefit the most in terms of CMV reactivation, acute GVHD incidence and NRM. Disclosures Chabannon: Gilead: Other: speaker's fees, hospitalities; Sanofi SA: Other: research support, speaker's fees, hospitalities; Novartis: Other: speaker's fees; Celgene: Other: speaker's fees; Terumo BCT: Other: speaker's fees; Miltenyi Biotech: Other: research support; Fresenius Kabi: Other: research support; EBMT: Other: Working Party Chair, Board member. Carlo-Stella:Boehringer Ingelheim: Consultancy; Rhizen Pharmaceuticals: Research Funding; Celgene: Research Funding; Genenta Science srl: Consultancy; F. Hoffmann-La Roche Ltd: Honoraria, Other: Travel, accommodations, Research Funding; ADC Therapeutics: Consultancy, Other: Travel, accommodations, Research Funding; Servier: Consultancy, Honoraria, Other: Travel, accommodations; Novartis: Consultancy, Research Funding; MSD: Honoraria; Sanofi: Consultancy, Research Funding; Amgen: Honoraria; AstraZeneca: Honoraria; Janssen Oncology: Honoraria; BMS: Honoraria; Janssen: Other: Travel, accommodations; Takeda: Other: Travel, accommodations. Santoro:Bayer: Consultancy, Speakers Bureau; MSD: Speakers Bureau; Sandoz: Speakers Bureau; Eisai: Consultancy, Speakers Bureau; BMS: Consultancy; Novartis: Speakers Bureau; Lilly: Speakers Bureau; Arqule: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; AstraZeneca: Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Servier: Consultancy, Speakers Bureau; Celgene: Speakers Bureau; Amgen: Speakers Bureau; Abb-Vie: Speakers Bureau; Roche: Speakers Bureau; Takeda: Speakers Bureau; BMS: Speakers Bureau. Blaise:Pierre Fabre medicaments: Honoraria; Molmed: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria; Sanofi: Honoraria.

Background CMV reactivation in seropositive, non-immunosuppressed adults with sepsis has been associated with worse clinical outcomes. To inform rational design of interventional trials determining whether CMV prevention improves outcomes, it is critical to identify the independence and strength of the association of CMV reactivation measures with clinically-relevant endpoints. Identification of patient factors associated with CMV reactivation would allow for optimization of the study population. Methods We performed a secondary pooled analysis of two prospective cohorts with sepsis: an observational cohort of ICU patients (n = 40) and the placebo cohort from a randomized, double-blind trial of ganciclovir to prevent CMV reactivation in acute critical illness (n = 66). Personnel blinded to the PCR results assessed clinical variables; CMV DNAemia was measured by quantitative plasma PCR twice weekly. Multivariable modeling using logistic and linear methods was used to examine the associations of CMV with clinical outcomes and between baseline patient factors and measures of CMV reactivation (adjusted for age, race, gender, transfusion status, study cohort, and APACHE score). Results CMV reactivation occurred at any level in 38/106 (36%), at >100 IU/mL in 25/106 (24%), and at >1,000 IU/mL in 14/106 (13%). In a multivariate model, CMV reactivation at any level, >100 IU/mL, or >1,000 IU/mL was associated with fewer days alive and not requiring ventilation: mean difference of −3.5 days ([95% CI −7.0, 0], P = 0.057), −5.1 days ([−8.9, −1.2], P = 0.012), and −6.1 days ([−10.9, −1.2], P = 0.016), respectively. Multiple measures of CMV reactivation were associated with other clinically-relevant outcomes, even after adjustment for baseline factors (Table 1). The association of APACHE score with CMV reactivation measures was inconsistent and with small effect size. We did not identify other patient variables associated with subsequent CMV reactivation. Conclusion CMV reactivation in seropositive adults with sepsis is independently and quantitatively associated with clinically-important outcomes, including death or continued hospitalization by day 28, ventilator-, ICU-, and hospital-free days. These effect sizes provide key data to inform design parameters of future interventional trials. Disclosures All authors: No reported disclosures.

Background Letermovir is a novel antiviral that was approved for cytomegalovirus (CMV) prophylaxis after allogeneic hematopoietic stem cell transplant (allo-HSCT). The objective was to assess the real-world outcomes of CMV prophylaxis with letermovir compared with preemptive therapy (PT) alone. Methods This retrospective pre- and post-study evaluated the clinical impact of using letermovir prophylaxis in CMV-seropositive allo-HSCT recipients at our institution. The electronic medical record was used to identify patients that received PT alone from July 2016 to November 2017 and letermovir prophylaxis from November 2017 to March 2019. The primary endpoint was the proportion of patients with CMV infection requiring PT through week 24 after transplant. Secondary endpoints included the proportion of patients with CMV infection requiring PT through week 14 after transplant, time to CMV infection requiring PT, incidence of CMV disease, CMV-related hospitalization and all-cause mortality through week 14 and 24 after transplant. Safety data included incidence and time to engraftment and adverse effects due to letermovir. Chi-squared and t-test were utilized for categorical and continuous data respectively. Results The baseline characteristics were similar (Table 1) and 78.7% of patients were high risk for CMV. Fewer patients in the letermovir group (n = 50) than in the historic control group (n = 100) had CMV infection requiring PT through week 24 after transplant (9 [18%] vs. 63 [63%], P < 0.001). The mean time to CMV infection requiring PT through week 24 after transplant was 93.4 days (28–161) in the letermovir group vs. 37.4 days (11–126) in the historic control group (P < 0.001). The all-cause mortality and incidence of CMV-related hospitalization were not statistically different between the two groups through week 24 after transplant (Table 2). The incidence and time to engraftment were not statistically different between the two groups (Table 3). Conclusion Letermovir prophylaxis in the real-world setting resulted in less CMV infection requiring PT when compared with a historic control of patients receiving PT alone. The majority of patients in the letermovir group experienced delayed-onset CMV reactivation. Letermovir was well-tolerated with no apparent myelosuppressive toxicities. Disclosures All authors: No reported disclosures.

e18533 Background: Post transplant cyclophosphamide (PTCY) has been shown to be an effective treatment for prevention of graft versus host disease (GVHD). However, this increased immune suppression rates may increase the risk of CMV reactivation. There is limited published data addressing CMV reactivation in this patient population. Additionally there is no data on the efficacy of prophylactic letermovir in the patients who have received PTCY. In this study we analyzed the incidence of CMV reactivation in patients treated with PTCY and those not treated with PTCY, as well as the efficacy of letermovir in preventing CMV reactivation in the PTCY population. Methods: We conducted a retrospective review of MUD, MRD, and haploidentical stem cell transplant patients at our institution from 1/1/2014 until 12/10/2018. We analyzed the incidence of CMV reactivation (PCR > 137 DNA IU/ml), peak of CMV PCR titer and time to reactivation within the first 100 days post-transplant. Results: There were 150 patients with at least 60 days of follow-up that were included in this study. These patients were split into three groups: No post-transplant cyclophosphamide (NPTCY) (N = 64), received post-transplant cyclophosphamide (PTCY) (N = 70), and received PTCY and letermovir prophylaxis. (L-PTCY) (N = 15). The incidence of CMV reactivation was increased in the PTCY patients when compared to the NPTCY (44% vs 29%). In the NPTCY patients the donor (D) serostatus increased the risk of CMV reactivation (Recipient (R)+ D+ 73% vs R+D-36%) conversely in the PTCY group the donor CMV status did not influence reactivation rates (R+D+ 52% vs R+D- 81%). The CMV reactivation rate in the L-PTCY patients was lower when compared to the PTCY patients (21% vs 44%), additionally the L-PTCY patients had much lower peak CMV titers compared to PTCY group (445 vs 2112 IU/ml). Conclusions: This study demonstrates that there is an increased incidence of CMV reactivation in patients who receive PTCY. Additionally, the donor CMV serostatus does not appear to influence the incidence of CMV reactivation in patients receiving post-transplant CY. Although the number of patients in the L-PTCY group is small, it does appear to be an effective prophylactic treatment in patients receiving PTCY.