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Background CMV infection can cause substantial morbidity and mortality in kidney transplant (KT) recipients due to an impairment in cell-mediated immunity (CMI) from immunosuppressive drugs. We investigated the role of CMI monitoring prior to and after transplant to predict CMV infection after KT. Methods A prospective study was performed between December 2020 and December 2021. All adult KT recipients underwent CMI measurement by investigating IFN-γ-producing T cells using enzyme-linked immunosorbent (ELISpot) assay before and one month post-transplant. The incidence of CMV infection within six months after transplant was reported, and predictors of CMV infection were analyzed using the Cox proportional hazard model. Results We included 93 KT recipients with a mean (SD) age of 44 (11) years; 59.1% were male, and 98.9% were CMV seropositivity. Twenty-two (23.7%) participants received anti-thymocyte globulin (ATG) for induction therapy. A median (IQR) of IFN-γ-producing T cells measured one month after transplant was significantly lower compared to before transplant (148 [54-389] vs. 763 [409-1,067] SFUs per 2.5 x 105 PBMCs, p < 0.001). Forty (42.9%) KT recipients who developed CMV infection appeared to have significantly less IFN-γ-producing T cells compared to those did not develop CMV infection (47.1%) (115 [33-237] vs. 238[76-492] SFUs/2.5x105 PBMCs, p=0.019). In univariate analysis, predictors for CMV infection included higher panel-reactive antibody (HR 1.02 [95%CI, 1.01-1.03], p< 0.001), receiving ATG for induction therapy (HR 3.45 [95%CI, 1.82-6.56], < 0.001) and lack of CMI one month after transplant defined as IFN-γ-producing T-cells of < 250 SFUs/2.5x105 PBMCs (HR 3.11 [95%CI, 1.36-7.10], p=0.007). In multivariate analysis, lack of CMI one month after transplant is the only predictor which remained independently associated with CMV infection (HR 3.1 [95%CI 1.2-7.80], p=0.019) (Table 1). Conclusion KT recipients with low IFN-γ-producing T cell responses are more likely to develop CMV infection post-transplant. Quantification of CMI using ELISpot assay could potentially predict those at risk of CMV infection after KT. Disclosures All Authors: No reported disclosures.

Background Patients with chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), are at risk of developing tuberculosis (TB). Due to their relatively immunosuppresses condition, reactivation from latent TB infection (LTBI) is the core pathogenesis in these populations. However, the prevalence of LTBI among Thai CKD patients, assessed by a high sensitivity and specificity test such as interferon-gamma release assay (IGRA), has never been thoroughly explored. We aimed to investigate the prevalence and predictors for LTBI among Thai CKD patients, including ESKD individuals receiving renal replacement therapy (RRT) either by hemodialysis (HD) or peritoneal dialysis (PD). Methods All CKD patients who underwent an investigation for LTBI status at Ramathibodi hospital were prospectively recruited from September 2020 to November 2021 and retrospectively reviewed from December 2020 to November 2021. Those with positive or borderline IGRA results using T SPOT®.TB without clinical or radiological findings compatible with active TB was diagnosed with LTBI. The LTBI prevalence was determined by CKD staging and type of dialysis. Predictors for LTBI were assessed by logistic regression analysis. Results A total of 199 CKD patients were enrolled; 102 prospectively and 97 retrospectively. There were 173 evaluable patients included with a mean (SD) age of 53 (16) years, and 44% were male. Of those, 95 (55%) had ESKD and maintained on RRT. Overall, 39 (22.5%) CKD patients had LTBI with the prevalence of 25%, 12.5%, 25%, 25% and 24.2% in those with CKD stage 1, 2, 3a, 3b and ESKD, respectively (p=0.89). Among ESKD patients, those who were maintained on HD had a higher proportion of LTBI than those on PD (28.9% vs. 5.3%, p=0.03). In multivariate analysis, drinking alcohol was significantly associated with LTBI (OR 8.51; [95%CI 1.24-58.38]; p=0.029), and HD therapy was marginally associated with LTBI (OR 8.14; [95%CI 0.95-69.91]; p=0.056) among ESKD patients. Conclusion In TB endemic settings, one-fifth of patients with CKD and a quarter of ESKD patients could carry LTBI status. Alcohol consumption and HD therapy could better identify high-risk ESKD patients and potentially screen for LBTI. Disclosures All Authors: No reported disclosures.

Background Polyomavirus-associated nephropathy (BKVAN) is one of the serious causes of allograft dysfunction and allograft loss in kidney transplant (KT) patients. Most of the patients were diagnosed with BKVAN within the first year after transplantation but some more cases of BKVAN occur later. A study focused on the differentiation between early and late-onset BKVAN is needed. Methods We conducted a retrospective cohort study among KT recipients at Ramathibodi Hospital between January 2010 – December 2020. The incidence of early-onset (diagnosed within 1 year) and late-onset (diagnosed after 1 year) BKVAN, as well as composite kidney allograft outcomes, were compared. Results From 1032 KT recipients, 645 (62.5%) were screened for BK viral infection. BKVAN was diagnosed in 83 (12.8%) patients. Of those, 46 (55.4%) and 37 (44.6%) were diagnosed with early-onset and late-onset BKVAN, respectively. Composite kidney allograft outcomes of GFR decline≥ 40% from baseline, graft loss or death were greater in early-onset BKVAN compared to late-onset BKVAN (7.5 vs 5.52 per 1000 person-months; hazard ratio 0.47; 95%CI, 0.23-0.95; P=0.037). In multivariate analysis, female gender and living-related kidney transplantation (LRKT) were independently associated with late-onset BKVAN compared to early-onset BKVAN. The more advanced the BKVAN diagnosis, the worse the allograft outcome occurs, even with optimizing immunosuppressive drugs and adjunctive therapy. Conclusion BKVAN could occur later after one-year post-transplantation, although relatively better composite kidney outcomes were observed compared to early-onset BKVAN. Female individuals who underwent living-related KT should be considered for BK virus preemptive monitoring beyond one year to detect this late-onset BK virus infection. Disclosures All Authors: No reported disclosures.

With an advance in therapy, there are increasing emerging and re-emerging opportunistic infections among patients with hematologic conditions and malignancy. Herein, we present a 56-year-old woman with primary myelofibrosis who developed combined tuberculosis (TB) and cryptococcosis with extensive pulmonary, pleural, and nodal involvement during ruxolitinib therapy. Marked clinical and radiologic improvements were undoubtedly evident after receiving anti-TB and antifungal therapies and pleural drainage. Hence, the presence of atypical clinical and radiologic manifestations and incomplete responses, despite receiving adequate antimicrobial treatment, should raise concerns regarding the combined emerging and re-emerging opportunistic infections and the possibility of unusual radiologic manifestations of cryptococcosis in a ruxolitinib-treated patient.

The case discussed involves a 69-year-old Thai woman who underwent orthotopic heart transplantation 9 months before this event. She presented with fever without localizing signs or symptoms. However, her chest images revealed mass-like consolidation in the left upper lobe. Blood culture and lung tissue identified Rhodococcus equi. She was successfully treated with a combination of antimicrobial therapy, optimization of immunosuppressants, and surgical resection.

Background: The association of influenza vaccination and heart failure (HF) hospitalization and mortality in Thai HF patients is unknown.Objective: To investigate associations between influenza vaccination and all-cause mortality or HF hospitalization in HF patients.Methods: We retrospectively reviewed medical records from two large tertiary care centers in Thailand (Ramathibodi hospital and Maharaj Nakorn Chiang Mai hospital) with newly diagnosed heart failure between 2013-2020 in an outpatient clinic. We examined the relationship between influenza vaccination and outcomes using a propensity-adjusted model.Results: Of 588 patients, 181 (31%) received influenza vaccination. During a mean follow-up of 57 months, influenza vaccination was associated with a 56% reduction in the risk of HF hospitalization or death (HF hospitalization or all-cause death: HR 0.44; 95% CI 0.31-0.63; ppConclusions: In patients with HF, influenza vaccination was associated with a reduced risk of HF hospitalization but not all-cause mortality.

Immunogenicity following an additional dose of Coronavirus disease 2019 (COVID-19) vaccine was investigated in an extended primary series among kidney transplant (KT) recipients. Eighty-five KT participants were randomized to receive either an mRNA (M group; n = 43) or viral vector (V group; n = 42) vaccine. Among them, 62% were male, with a median (IQR) age of 50 (43-59) years and post-transplantation duration of 46 (26-82) months. At 2 weeks post-additional dose, there was no difference in the seroconversion rate between the M and V groups (70% vs. 65%, p = .63). A median (IQR) of anti-RBD antibody level was not statistically different between the M group compared with the V group (51.8 [5.1-591] vs. 28.5 [2.9-119.3] BAU/ml, p = .18). Furthermore, the percentage of participants with positive SARS-CoV-2 surrogate virus neutralization test results was not statistically different between groups (20% vs. 15%, p = .40). S1-specific T cell and RBD-specific B cell responses were also comparable between the M and V groups (230 [41-420] vs. 268 [118-510], p = .65 and 2 [0-10] vs. 2 [0-13] spot-forming units/10

Multi-drug resistant organisms have been emerging among kidney transplant (KT) recipients with bloodstream infections (BSI). The investigation for epidemiology, risk factors and outcome of these infections following KT was initiated.A retrospective study of all adult KT recipients who developed a BSI within the first year after KT in 2016 at a single transplant center was conducted. The cumulative incidence of BSI was estimated with Kaplan-Meier methodology. Clinical characteristics and outcome were extracted. Risk factors were analyzed with Cox proportional hazards models.Among 171 KT recipients, there were 26 (15.2%) episodes of BSI. Fifty-nine percent were men and the mean ± SD age was 43 ± 12 years. The cumulative incidence of BSIs was 10.1% at 1 month, 13.5% at 6 months, and 15.2% at 12 months. Gram-negative bacteria were responsible for 92% of BSIs, Escherichia coli was the most common pathogen (65%) followed by Klebsiella pneumoniae (11%). Among those, 71% were resistant to extended-spectrum cephalosporins. The genitourinary tracts were the predominant source of BSIs (85%). The second kidney transplantation (HR, 4.55; 95% CI, 1.24-16.79 [P = 0.02]) and receiving induction therapy (HR, 3.05; 95% CI, 1.15-8.10 [P 0.03]) were associated with BSI in a multivariate analysis. One patient (4%) developed allograft rejection, allograft failure and death from septic shock.One out of six KT recipients could develop BSI from gram-negative bacteria within the first year after transplant, particularly in those that received the second transplantation or induction therapy.

Introduction Knowing the epidemiology of acute meningitis may guide physicians to promptly administer appropriate empirical therapy, thereby minimizing morbidity and mortality. We aimed to determine the etiology, clinical manifestations, cerebrospinal fluid (CSF) findings, and outcomes of patients with acute meningitis. Methods We conducted a retrospective cohort study among a total 89 adult (age ≥15 years) patients with acute meningitis. Results Among them, 48 (53.9%) patients were men; the median age (interquartile range; IQR) was 49 (32.1–63.8) years. The most common coexisting conditions were HIV infection (30%), prednisolone therapy (16.9%), and diabetes mellitus (15.7%). Common clinical presentations were fever (74%), headache (70.8%), and confusion (31.5%). Causes of acute meningitis were Cryptococcus neoformans (37%), bacteria (31.5%), Mycobacterium tuberculosis (27%), and viruses (4.5%). In multivariate logistic regression, predicting factors of acute bacterial meningitis were higher white blood cells (WBCs) in a complete blood count [odds ratio (OR) 1.01 per increase of 100 cells/mm3; 95% confidence interval (CI) 1.00–1.02, p = 0.031], no HIV infection (OR 0.08; 95% CI 0.01–0.72, p = 0.023), and higher serum sodium (OR 1.13; 95% CI 1.01–0.23, p = 0.029). Overall, the median (IQR) duration of hospitalization was 23 (11–29) days. A total 26 (29%) patients had complications, such as septic shock, hydrocephalus, seizure, and brain edema. The in-hospital mortality rate was 7.9%. Conclusions In this setting, the most common cause of acute meningitis in adults was cryptococcosis followed by tuberculosis. Awareness of local epidemiology and patients’ risk factors are important to initiate appropriate antimicrobial therapy.

Antimicrobial stewardship (AMS) is a coherent set of actions to optimize antimicrobial use, improve patient outcomes, and reduce antimicrobial resistance (AMR). Thailand's national strategic plan has included AMS since 2017. Due to an increased risk of infection and AMR, solid organ transplant (SOT) recipients can benefit from antimicrobial stewardship programs (ASPs). However, the AMS in SOT has not been well defined. Balancing ASPs with the need for early and frequent antimicrobial treatment in this population is challenging. This review assesses the barriers and potential strategies of AMS in SOT in the setting of Thailand.We used PubMed to identify published articles on AMS in organ transplantation in Thailand from January 2013 to January 2022. We also searched local literature and local data from Google Scholar and Google. Finally, we described the AMS experience at Ramathibodi hospital as a proxy for transplant centers in Thailand.There was no specific article on AMS in SOT in Thailand. At our hospital, ASPs have been part of the hospital's routine patient care, including the practice in the transplant unit. Modifiable challenges to AMS in SOT include prescriber opposition, diagnosis uncertainty, and lack of high quality. Both systems and individualized approaches should be implemented to overcome these barriers. The potential interventions include shortening antibiotic time-out, updating clinical guidelines, continuing education, handshake ASP, adopting new technology, and further research.There are limited data on AMS in organ transplantation in Thailand. Strategic priorities should focus on modifiable barriers tailored to organ transplantation. Quality improvement should be ensured by process and outcome measures.

BACKGROUND AND AIMS Patients with end-stage kidney disease (ESKD) are at risk of coronavirus disease 2019 infection and its associated complications. A previous study demonstrated that patients with ESKD on dialysis generated suboptimal humoral immune response (HIR) and lower seroconversion rate after two-dose inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination as compared to healthy individuals. In this study, we examined HIR of the additional dose of ChAdOx1 nCoV-19 vaccine following a standard two-dose inactivated whole-virus SARS-CoV-2 vaccination in patients on dialysis, and compared to those of healthy controls. METHOD We recruited 59 patients with ESKD [31 patients on haemodialysis (HD) and 28 on peritoneal dialysis (PD)) and 16 healthy controls who received two doses of inactivated SARS-CoV-2 vaccine (V2) from Ramathibodi hospital and Banphaeo General Hospital, Bangkok, Thailand, from July 2021 to September 2021. All participants were administered a third dose of the ChAdOx1nCoV-19 vaccine (V3) with a 6-week interval between the V2 to V3. HIR was measured 2 weeks after V2 and V3 using SARS-CoV-2 immunoglobulin G (IgG) assay, which detects antibodies against the S1 receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Median anti-RBD IgG titer and seroconversion rate, defined as anti-RBD IgG titre ≥ 7.1 BAU/mL, were compared among ESKD patients and to those of healthy controls using the Kruskal–Wallis H test and the chi-squared test, respectively. RESULTS Baseline characteristics of patients on HD, PD and healthy controls are shown in Table 1. Demographic characteristics and baseline laboratory parameters were comparable between the HD and PD groups, except for a lower mean serum albumin level in the PD group (P At 2 weeks after V3, the median anti-RBD IgG titres were significantly increased in all groups compared to those levels after V2 (85[33–412] versus 1566 [861–3083] BAU/mL for patients on HD, 81 [15–144] versus 913 [293–1359] BAU/mL for patients on PD and 250 [92–603] versus 2210 [1531–2782] BAU/mL for healthy controls; P CONCLUSION We suggest that an additional ChAdOx1 nCoV-19 vaccine after a primary two doses inactivated SARS-CoV-2 vaccination could improve seroconversion rate and magnitude of humoral immune response in patients on dialysis. The durability of the immune response to this vaccination regimen requires further study.

Molecular testing has been utilized for cytomegalovirus (CMV) pneumonitis (CMVP) diagnosis, although its validity and optimal cut-off values remain limited.A prospective study of CMVP diagnosis among immunocompromised patients was conducted by measuring quantitative CMV DNA polymerase chain reaction in plasma and bronchoalveolar lavage fluid (BALF).Forty-five adult immunocompromised patients were investigated. Thirty-two patients (71%) received immunosuppressive therapy. Eleven patients (24%) were confirmed to have CMVP. Of those, three and eight patients were classified as proven and probable CMVP, respectively. Median (IQR) plasma CMV DNA loads in CMVP and non-CMVP were 41,939 (4,424-122,608) and 0 (0-44) IU/mL, respectively (p0.001). Median (IQR) BALF CMV DNA loads in CMVP and non-CMVP were 379,652 (163,800-1,254,000) and 0 (0-1,348) IU/mL, respectively (p0.001). A significant correlation was observed between plasma and BALF CMV DNA loads (r=0.887, p0.001). Plasma CMV DNA load of 831 IU/mL was established as a cut-off value for diagnosing CMVP (AUC 0.9987, sensitivity 100%, specificity 94.1%, positive predictive value 84.5%, negative predictive value 100%).A strongly positive correlation was observed between CMV DNA loads measured in plasma and BALF. CMV DNA load quantification could potentially assist in diagnosing CMVP in immunocompromised patients, although bronchoscopy remains encouraged for a definitive diagnosis.

Cytomegalovirus (CMV) challenges physicians who care for immunocompromised transplant recipients. Antiviral drugs are the cornerstone in the prevention and treatment of CMV disease, but they have t...

Introduction Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) causes an ongoing outbreak of respiratory illness called coronavirus disease 2019 (COVID‐19). The clinical course could be ranging from mild to severe illness especially the individuals with an immunocompromised condition such as solid organ transplant recipients. Method We described a family cluster of COVID‐19 patients who were admitted during 3rd April 2020 to 30th April 2020. COVID‐19 was confirmed by a presence of SARS‐CoV‐2 ribonucleic acid in the respiratory specimens detected by a qualitative, real‐time reverse transcription‐polymerase chain reaction. The study focused on the clinical course and management of our cases. Results A family cluster of four laboratory‐confirmed COVID‐19 patients, one of those carried an underlying kidney transplant (KT) receiving immunosuppressants. Clinical presentation and severity of our case series are variable depending on each individual immune status. By far, a KT recipient seems to develop more severity despite antiviral therapy, cessation of immunosuppressant, and aggressive intensive care support. Conclusion Our case series plausibly affirmed a person‐to‐person transmission and potentially severe disease in the transplant population. Clinicians who are encountering with transplant recipients should be aware of possible transmission among family members., A family cluster of four laboratory‐confirmed COVID‐19 patients. Our case series plausibly affirmed a person‐to‐person transmission and potentially severe disease in the transplant population. Clinicians who are encountering with transplant recipients should be aware of possible transmission among family members.

Background Cytomegalovirus (CMV) infection is one of the leading causes of morbidity and mortality in kidney transplantation (KT) recipients. We investigated the association of CMV serostatus and patient outcomes within the first year after KT. Methods All KT recipients between January 1, 2007 and December 31, 2017 were identified from the Thai Transplant Registry. The prevalence rates of allograft loss and mortality within the first year after KT were estimated by the Kaplan-Meier method. The CMV serostatus in donors (D) and recipients (R) was assessed as a prognostic factor for allograft loss and mortality within the first year by the Cox proportional hazards model. Results During the 10-year study period (2007-2017), there were 4556 KT recipients with a mean ± standard deviation age of 43 ± 14 years, and 63% of the recipients were male. Deceased-donor KT and induction therapy were performed in 52% and 58% of the recipients, respectively. Among the 3907 evaluable patients, the rates of cases with D+/R+, D+/R−, D−/R+, and D−/R− as the CMV serostatus were 88.9%, 6.1%, 2.9%, and 1.9%, respectively. The estimated prevalence rates of allograft loss and mortality within the first year were 3.8% and 2.8%, respectively. In univariate analysis, CMV D+/R− serostatus was significantly associated with mortality (hazard ratio [HR], 2.10; 95% confidence interval [CI], 1.18-3.75; P = .01) but not with an allograft loss (HR, 1.51; 95% CI, 0.85-2.66; P = .16) within the first year after KT. In multivariate analysis, CMV D+/R− serostatus of D+/R− was associated with mortality within the first year after KT (HR, 2.04; 95% CI, 1.05-3.95; P = .04). Other independent prognostic factors for mortality were old recipient age, deceased-donor KT, and hemodialysis after KT. Conclusions In a national setting with predominant CMV seropositivity in both D and R, CMV seromismatch was associated with poor patient survival within the first year after KT.

Background: Persistent anemia has been described in kidney transplant (KTx) recipients with parvovirus B19 virus infection. However, the epidemiology of parvovirus B19 and parvovirus B19-related anemia after KTx remains unclear. We conducted this systematic review (1) to investigate the incidence of parvovirus B19 infection after KTx and (2) to assess the incidence of parvovirus B19 among KTx patients with anemia. Materials and Methods: A systematic review was conducted in EMBASE, MEDLINE, and Cochrane databases from inception to March 2019 to identify studies that reported the incidence rate of parvovirus B19 infection and/or seroprevalence of parvovirus B19 in KTx recipients. Effect estimates from the individual studies were extracted and combined using random-effects, generic inverse variance method of DerSimonian and Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42019125716). Results: Nineteen observational studies with a total of 2108 KTx patients were enrolled. Overall, the pooled estimated seroprevalence of parvovirus B19 immunoglobulin G was 62.2% (95% confidence interval [CI]: 45.8%–76.1%). The pooled estimated incidence rate of positive parvovirus B19 DNA in the 1st year after KTx was 10.3% (95% CI: 5.5%–18.4%). After sensitivity analysis excluded a study that solely included KTx patients with anemia, the pooled estimated incidence rate of positive parvovirus B19 DNA after KTx was 7.6% (95% CI: 3.7%–15.0%). Among KTx with anemia, the pooled estimated incidence rate of positive parvovirus B19 DNA was 27.4% (95% CI: 16.6%–41.7%). Meta-regression analysis demonstrated no significant correlations between the year of study and the incidence rate of positive parvovirus B19 DNA (P = 0.33). Egger's regression asymmetry test was performed and demonstrated no publication bias in all analyses. Conclusion: The overall estimated incidence of positive parvovirus B19 DNA after KTX is 10.3%. Among KTx with anemia, the incidence rate of positive parvovirus B19 DNA is 27.4%. The incidence of positive parvovirus B19 DNA does not seem to decrease overtime.

Background BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) could cause allograft dysfunction among kidney transplant (KT) recipients. Intact BKPyV-specific immunity is correlated with viral containment, therefore clinical and immunological characteristics related to BKVAN after KT needs to be explored. Methods We prospectively investigated an association between clinical baseline characteristics, BK polyomavirus (BKPyV)-specific immunity, and BKPyV-associated nephropathy (BKPyVAN) in KT recipients. BKPyV-specific immunity, measured with intracellular cytokine assays, is reported as the percentage of IFN-γ-producing CD4+ T, CD8+ T, natural killer (NK), and NKT cells after large-T antigen and viral capsid protein 1 (VP1) stimulation. Results Among 100 KT patients, BKPyVAN occurred in 18% within one-year post-KT. There were 70 patients (70%) who received an induction immunosuppressive therapy. Diabetic nephropathy was significantly associated with BKPyVAN. Among 40 patients who were eligible for the immunological study. In a multivariate analysis, pre-KT %VP1-specific NK cells were independently associated with BKPyVAN (HR, 1.209; 95%CI, 1.055–1.386; P = 0.006). In those with BKPyVAN, the mean %NK (coefficient, 1.202; 95%CI, 0.033–2.371; P = 0.04), %VP1-specific NK (coefficient, 2.602; 95%CI, 1.083–4.121; P = 0.001), and %NKT (coefficient, 0.199; 95%CI, 0.051–0.348; P = 0.008) cells at 1-month post-KT were significantly higher than those pre-KT. Thus, increasing NK, VP1-specific NK, and NKT cell proportions were observed among KT recipients who developed BKPyVAN within the first year. Conclusion KT recipients with underlying diabetes and the presence of BKPyV-specific NK- and NKT-cell immunity could be at risk of BKPyVAN after KT. BKPyV-specific innate immune monitoring could potentially stratify those at risk of BKPyVAN among KT recipients. (Thai Clinical Trials Registry, TCTR20190404004)

Vaccination with inactivated SARS-CoV-2 virus produces suboptimal immune responses among kidney transplant (KT), peritoneal dialyzed (PD), and hemodialyzed (HD) patients. Participants were vaccinated with two-dose inactivated SARS-CoV-2 vaccine (V2) and a third dose of ChAdOx1 nCoV-19 vaccine (V3) at 1–2 months after V2. We enrolled 106 participants: 31 KT, 28 PD, and 31 HD patients and 16 controls. Among KT, PD, and HD groups, median (IQR) of anti-receptor binding domain antibody levels were 1.0 (0.4–26.8), 1092.5 (606.9–1927.2), and 1740.9 (1106–3762.3) BAU/mL, and percent neutralization was 0.9 (0–9.9), 98.8 (95.9–99.5), and 99.4 (98.8–99.7), respectively, at two weeks after V3. Both parameters were significantly increased from V2 across all groups (p p 90% in PD, HD, and control groups, which was higher than that in KT recipients (74%, p

Background: Black kidney transplant recipients have worse allograft outcomes compared to White recipients. The feature importance and feature interaction network analysis framework of machine learning random forest (RF) analysis may provide an understanding of RF structures to design strategies to prevent acute rejection among Black recipients. Methods: We conducted tree-based RF feature importance of Black kidney transplant recipients in United States from 2015 to 2019 in the UNOS database using the number of nodes, accuracy decrease, gini decrease, times_a_root, p value, and mean minimal depth. Feature interaction analysis was also performed to evaluate the most frequent occurrences in the RF classification run between correlated and uncorrelated pairs. Results: A total of 22,687 Black kidney transplant recipients were eligible for analysis. Of these, 1330 (6%) had acute rejection within 1 year after kidney transplant. Important variables in the RF models for acute rejection among Black kidney transplant recipients included recipient age, ESKD etiology, PRA, cold ischemia time, donor age, HLA DR mismatch, BMI, serum albumin, degree of HLA mismatch, education level, and dialysis duration. The three most frequent interactions consisted of two numerical variables, including recipient age:donor age, recipient age:serum albumin, and recipient age:BMI, respectively. Conclusions: The application of tree-based RF feature importance and feature interaction network analysis framework identified recipient age, ESKD etiology, PRA, cold ischemia time, donor age, HLA DR mismatch, BMI, serum albumin, degree of HLA mismatch, education level, and dialysis duration as important variables in the RF models for acute rejection among Black kidney transplant recipients in the United States.

INTRODUCTION Patients with end-stage kidney disease (ESKD) are at risk of severe coronavirus disease and mortality. Immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated whole-virus vaccine in patients with ESKD has never been explored. METHODS We conducted a prospective cohort study of 60 patients with ESKD and 30 healthy controls. All participants received two doses of an inactivated whole-virus SARS-CoV-2 vaccine (Sinovac Biotech Ltd) 4 weeks apart. SARS-CoV-2-specific humoral and cell-mediated immune responses were investigated and referenced with healthy controls. RESULTS After two doses, an anti-receptor-binding domain immunoglobulin G of 50 AU/ml or greater was present in 53 of 60 patients (88%) in the ESKD group and all participants (100%) in the control group (P = 0.05). The percentage of patients with ESKD and controls with neutralizing antibodies of 35% threshold or greater was 58% and 88%, respectively (P = 0.01). Furthermore, the proportion of patients with ESKD and S1-specific T cell response was comparable with controls (82% vs. 77%, P = 0.45). Old age, high ferritin level, and low absolute lymphocyte count were independently associated with poor humoral immune responses. CONCLUSIONS Patients with ESKD could develop similar SARS-CoV-2-specific cell-mediated immune responses compared to healthy controls, although suboptimal humoral immune responses were observed following two doses of SARS-CoV-2 vaccination. Therefore, patients with ESKD and the abovementioned factors are at risk of generating inadequate humoral immune responses, and a vaccine strategy to elicit greater immunogenicity among these relatively immunocompromised patients is warranted. (Thai Clinical Trials Registry, TCTR20210226002).

We presented an initial pilot study report focused on immunogenicity and safety following an inactivated whole-virus severe acute respiratory syndrome coronavirus 2 vaccination among kidney transplant (KT) recipients. At four weeks after the first dose of vaccine, the level of anti–receptor-binding domain IgG antibody was not significantly different compared to before vaccination in 30 KT recipients (p = 0.45). Moreover, a significant lower mean (95% CI) anti–receptor-binding domain IgG antibody was observed compared to 30 immunocompetent controls (2.4 [95% CI 1.3-3.5] vs. 173.1 [95% CI 88.3-2,457.9] AU/mL, p < 0.001). Mild adverse events included fever (17%) and localized pain at the injection site (14%) were observed after vaccination.

Background In the United States, increasing ethnic diversity has been apparent. However, the epidemiology and trends of BKV genotypes remain unclear. This meta-analysis was conducted with the aim to assess the prevalence of BKV genotypes among kidney transplant (KTx) recipients in the United States. Methods A comprehensive literature review was conducted through October 2018 utilizing MEDLINE, Embase, and Cochrane Database to identify studies that reported the prevalence of BKV subtypes and/or subgroups in KTx recipients in the United States. Pooled prevalence rates were combined using random effects, generic inverse variance method. The protocol for this study is registered with PROSPERO (no. CRD42019134582). Results A total of eight observational studies with a total of 193 samples (urine, blood, and kidney tissues) from 188 BKV-infected KTX recipients were enrolled. Overall, the pooled estimated prevalence rates of BKV subtypes were 72.2% (95% confidence of interval [CI]: 62.7-80.0%) for subtype I, 6.8% (95% CI: 2.5-16.9%) for subtype II, 8.3% (95% CI: 4.4-15.1%) for subtype III, and 16.1% (95% CI: 10.4-24.2%) for subtype IV, respectively. While metaregression analysis demonstrated a significant positive correlation between year of study and the prevalence of BKV subtype I (slopes = +0.1023, P = .01), there were no significant correlations between year of study and percentages of BKV subtype II-IV (P > .05). Among KTx recipients with BKV subtype I, the pooled estimated percentages of BKV subgroups were 22.4% (95% CI: 13.7-34.5%) for subgroup Ia, 30.6% (95% CI: 17.7-47.5%) for subgroup Ib1, 47.7% (95% CI: 35.8-59.9%) for subgroup Ib2, and 4.1% (95% CI:1.2-13.3%) for subgroup Ic, respectively. Conclusion BKV subtype I is the most prevalent subtype among KTx recipients in the United States and its prevalence seems to increasing overtime. Subgroup Ib2 is the most common subgroup among BKV subtype I.

BACKGROUND Late-onset cytomegalovirus (CMV) infection (LCI) has been emerging mong solid-organ transplant recipients. We explored clinical characteristics, risk factors, and outcomes of LCI in kidney transplantation (KT) recipients. METHODS A retrospective study of all adult KT recipients with LCIs (that occurred >6 months after transplant) from 2016 to 2018 was conducted. Clinical characteristics and outcomes were extracted. Risk factors of LCI were analyzed using Cox proportional hazards models. RESULTS A total of 518 KT recipients were included. Ninety-eight percent had donor CMV-seropositive and recipient CMV-seropositive status (D+/R+). Ten (2%) KT recipients developed LCI with a median onset of 14 (interquartile range, 8-15) months. Those included asymptomatic CMV infection (40%) and tissue-invasive disease (60%). CMV D+/R- serostatus and a prior episode of rejection within 6 months were associated with LCI (hazard ratio, 17.35; 95% confidence interval, 3.60-83.63; P < .001) and (hazard ratio, 38.15; 95% confidence interval, 6.15-236.72; P < .001), respectively. There was no difference in the rate of allograft failure and mortality in those with LCI compared with those with early-onset CMV infection. CONCLUSION LCI is uncommon after KT. Those with CMV seromismatch and a prior episode of rejection were more likely to develop LCI. Clinical and allograft outcomes were not different among each group.

Background High plasma cytomegalovirus (CMV) DNA load is generally associated with CMV tissue-invasive disease in solid organ transplant recipients. However, some tissue-invasive diseases, especially CMV gastrointestinal (GI) disease, have undetectable to very low plasma CMV DNA loads. Highly sensitive nucleic acid amplification testing (NAAT) has been increasingly used to quantify low-level CMV DNA loads. Our primary objective was to investigate the epidemiology of CMV GI disease and evaluate the validity of plasma CMV NAAT for the diagnosis of CMV GI disease in kidney transplant (KT) recipients. Methods We conducted a retrospective study of all KT recipients who developed CMV GI disease from January 2016 to December 2018. Plasma CMV DNA load was measured using real-time PCR. The cut-off value of plasma CMV DNA load for diagnosing and risk factors of CMV GI disease were analyzed. Results A total 17 (3.4%) cases of CMV GI disease occurred in 494 KT recipients. Fifteen (88%) patients had CMV D + /R + serostatus. Fourteen (82%) patients developed CMV GI disease within 6 months after KT. Plasma CMV DNA loads were detectable in all (100%) patients with a median load 11,102 (IQR 2,935-107,160) IU/mL. A plasma CMV DNA load of 4,063 IU/mL was established as al cut-off for diagnosing CMV GI disease (AUC 0.74, sensitivity 76.5%, specificity 70%, PPV 68, NPV 78). In multivariate analysis, prolonged cold ischemic time (HR 1.14, 95%CI 1.05-1.23, p=0.002) and CMV D + /R - serostatus (HR 9.31, 95%CI 2.12-40.74, p=0.003) were associated with CMV GI disease. Conclusions Using highly sensitive NAAT could potentially assist in the diagnosis of CMV GI disease in a CMV D + /R + serostatus setting. KT recipients with CMV seromismatch and prolonged cold ischemic time are at higher risk of CMV GI disease.

Background Although cytomegalovirus (CMV)-seropositive solid organ transplant recipients have a relatively lower risk of CMV infection than CMV-seronegative recipients who receive allograft from CMV-seropositive donors, some patients remain at risk of CMV infection after transplant. We investigated the pretransplant CMV-specific humoral immunity (CHI) and other CMV infection predictors in CMV-seropositive kidney transplant (KT) recipients. Methods This retrospective study was conducted on adult CMV-seropositive KT recipients during 2017 and 2018. The cumulative incidence of CMV infection was estimated using the Kaplan-Meier method. CHI, measured with an enzyme-linked fluorescent immunoassay and other predictors for CMV infection, was analyzed using Cox proportional hazards models. Results Of the 340 CMV-seropositive KT recipients (37% female; mean ± SD age, 43 ± 11 years), 69% received deceased-donor allograft and 64% received induction therapy. During a mean follow-up of 14 months, the cumulative incidence of CMV infection was 14.8%. In multivariate analysis, low pretransplant CHI (defined as anti-CMV immunoglobulin [IgG] titer Conclusions A low pretransplant CHI is independently associated with post-transplant CMV infection in CMV-seropositive KT recipients. A quantitative anti-CMV IgG assay could potentially stratify CMV-seropositive patients at risk of CMV infection after KT.