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Background Hemolysis following the administration of intravenous immunoglobulin (IVIG) is an important adverse event (AE). While the monocyte monolayer assay (MMA) has been used to predict in vivo hemolysis when serologically incompatible blood may be transfused, it has also been shown to correlate with IVIG-associated hemolysis. In this study, the MMA was examined for its utility in assessing the risk of hemolysis after IVIG. Study design and methods Forty-two non-blood group O patients receiving high-dose IVIG (≥2 g/kg) were examined using an autologous and allogeneic MMA. Hemolysis was defined by a drop in hemoglobin of ≥1 g/L, a positive direct antiglobulin test (DAT) and eluate, and a decrease in haptoglobin or increase in lactate dehydrogenase and/or reticulocytes. Results Forty-two patients provided 50 assessable postinfusion samples, with hemolysis observed in 20 (40%) of cases. Autologous MMA using post-IVIG red blood cells significantly correlated with clinical outcomes when compared to allogeneic MMA (P = .0320 vs .5806, t test). No significant difference in receiver operating characteristics was observed when comparing autologous MMA testing against DAT for the diagnosis of IVIG-associated hemolysis. However, when using samples collected 5 to 10 days after receipt of high-dose IVIG, the autologous MMA had higher sensitivity than the DAT. Conclusion MMA testing with autologous monocytes collected 5 to 10 days after receipt of high-dose IVIG can be used for the diagnosis of IVIG-associated hemolysis and may be of particular value in cases in which the Day 5 to 10 DAT is negative.

Background Platelet transfusions are used to prevent or control bleeding in patients with thrombocytopenia or platelet dysfunction. The pretransfusion platelet count threshold has been studied extensively in multiple patient settings yielding high-quality evidence that has been summarized in several comprehensive evidence-based platelet guidelines. Study design and methods A prospective 12-week audit of consecutive platelet transfusions using validated and evidence-based adjudication criteria was conducted. Patient demographic, laboratory, and transfusion details were collected with an electronic audit tool. Each order was adjudicated either electronically or independently by two transfusion medicine physicians. The aim was to determine platelet transfusion appropriateness and common scenarios with deviations from guidelines. Results Fifty-seven (38%) of 150 hospitals provided data on 1903 platelet orders, representing 90% of platelet usage in the region during the time period. Overall, 702 of 1693 adult (41.5%) and 133 of 210 pediatric orders (63.3%) were deemed inappropriate. The most common inappropriate platelet order was for prophylaxis in the absence of bleeding or planned procedure in patients with hypoproliferative thrombocytopenia and a platelet count over 10 x 109 /L (53% of inappropriate orders in adults and 45% in pediatrics). Platelet transfusions ordered with either a preprinted transfusion order set (odds ratio [OR], 1.97; 95% confidence interval [CI], 1.44-2.73) or technologist prospective screening (OR, 1.40; 95% CI, 1.10-1.78) were more likely to be appropriate. Conclusion There is a discrepancy between clinical practice and evidence-based platelet guidelines. Broad educational and system changes will be needed to align platelet transfusion practice with guideline recommendations.

Hemolytic anemia resulting from IV Immunoglobulin (IVIG) treatment can be a serious complication, especially for those with underlying conditions with a high level of inflammation and after administration of high IVIG dosages, such as Kawasaki disease (KD), a multisystem vasculitis affecting young children. This hemolysis is caused by antibodies against blood groups A and B, but the precise mechanism for hemolysis is not known. We performed a single center, partly retrospective, partly prospective study of a cohort of 581 patients who received IVIG for treatment of KD from 2006 to 2013. Factors associated with hemolysis were identified through univariable and multivariable logistic regression. Six IVIG preparations were assayed for their hemolytic effect with serological and cellular assays to clarify the mechanism of red cell destruction. During the study period, a sudden increase in the incidence of hemolysis was observed, which coincided with the introduction of new IVIG preparations in North America that contained relatively high titers of anti-A and anti-B. These blood-group–specific antibodies were of the immunoglobulin G2 (IgG2) subclass and resulted in phagocytosis by monocyte-derived macrophages in an FcγRIIa-dependent manner. Phagocytosis was increased in the presence of proinflammatory mediators that mimicked the inflammatory state of KD. An increased frequency of severe hemolysis following IVIG administration was caused by ABO blood-group–specific IgG2 antibodies leading to FcγRIIa-dependent clearance of erythrocytes. This increase in adverse events necessitates a reconsideration of the criteria for maximum titer (1:64) of anti-A and anti-B in IVIG preparations.

Background Intravenous Immune Globulin (IVIG) is used to treat numerous immune-mediated and inflammatory conditions. There is growing awareness of hemolysis, occasionally severe, as a side-effect of this therapy. While most cases are associated with anti-A and/or anti-B isoagglutinins, the frequency and mechanism of hemolysis remain poorly characterized. Study design and methods A prospective observational study was conducted to determine incidence, natural history and risk factors for IVIG-mediated hemolysis. A total of 99 infusions of high-dose IVIG (2 g/kg or higher) administered to 78 non-group O patients were monitored and graded according to Canadian IVIG Hemolysis Pharmacovigilance Group. Serum ferritin and C3/C4 levels were monitored as indicators of macrophage activation and complement consumption, respectively. Supplementary investigations included assessment for ABO zygosity, Secretor status, FcR polymorphisms, eluate IgG subclass, monocyte monolayer assay, and a panel of cytokines. Results Hemolysis was observed in 32 of 99 (32%) of infusions, with 19 of 99 (19%) grade 2 or higher. Hemolysis was only apparent 5-10 days after a completed IVIG infusion in 84% of cases and was associated with increases in serum ferritin without complement-consumption. In univariate analysis, increased risk was observed in group AB patients, first-time IVIG recipients, those not taking immuosuppressive medications, or patients treated with a specific IVIG brand; however, in multivariate analysis, product association was no longer observed. No other patient- or practice-related risk factors were identified. Conclusion IVIG-mediated hemolysis is common and frequently severe. Monitoring for 5-10 days following an infusion should be considered in non-O patients receiving high-dose IVIG with known risk factors.

BACKGROUND Alloantibodies to the low-frequency antigen Scianna-2 (Sc2) have been implicated in cases of hemolytic disease of the fetus and newborn but never in hemolytic transfusion reactions (HTRs); thus, the clinical significance of anti-Sc2 has yet to be fully addressed. STUDY DESIGN AND METHODS A 26-year-old woman with thalassemia presented rigors, fever, nausea, abdominal pain, and hemolytic biochemistry after exposure to 75 mL of plasma-reduced red blood cells (RBCs). The RBC unit was issued by electronic crossmatch but was 3+ incompatible on recrossmatch by gel indirect antiglobulin test (IAT). The patient had anti-Sc2 previously identified, but considered to be clinically insignificant. The transfusion history was reviewed and a monocyte monolayer assay (MMA) was performed. RESULTS The patient was investigated for a RBC reaction 9 years prior, when she developed symptoms of HTR. The RBC unit was crossmatched by immediate spin due to consistent screen negativity. Full crossmatch found the RBC 1+ incompatible by gel IAT with both pre/post samples, while direct antiglobulin test was negative (pre) and 1+ immunoglobulin G positive (post). The antibody remained unidentified and she was committed to gel IAT crossmatch. Two-years later, the specificity to Sc2 was deduced when one RBC unit was found 3+ incompatible. Finally, the transfusion reaction reported herein occurred when she received by happenstance RBCs from the same donor who was associated with the remote reaction 9 years earlier. MMA yielded highly positive phagocytic indices only for Sc2+ RBCs, including the donor's RBCs that triggered the severe HTR. CONCLUSION This is the first case of HTR caused by anti-Sc2 confirmed by clinical findings and MMA.

TO THE EDITOR: Although frequently effective[1][1],[2][2] and usually benign, high-dose (2 g/kg) intravenous immunoglobulin (IVIG) therapy can result in marked red blood cell (RBC) hemolysis, which in some cases is life threatening in severity.[3][3][⇓][4]-[5][5] The mechanism by which this

BACKGROUND The optimal method of providing transfusion medicine (TM) education has not been determined. Transfusion Camp was established in 2012 at the University of Toronto as a centrally delivered TM education program for postgraduate trainees. The impact of Transfusion Camp on knowledge, attitudes, and self-reported behavior was evaluated. METHODS Didactic lectures (delivered locally, by webinar, or recorded) and locally facilitated team-based learning seminars were delivered over 5 days during the academic year to 8 sites: 7 in Canada and 1 in the United Kingdom. Knowledge assessment using a validated 20-question multiple-choice exam was conducted before and after Transfusion Camp. Attitudes and self-reported behavior were collected through a survey. RESULTS Over 2 academic years (July 2016 to June 2018), 390 trainees from 16 different specialties (predominantly anesthesia, 41%; hematology, 14%; and critical care, 7%) attended at least 1 day of Transfusion Camp. The mean pretest score was 10.3 of 20 (±2.9; n = 286) compared with posttest score of 13.0 (±2.8; n = 194; p < 0.0001). Lower pretest score and greater attendance (4-5 days compared with 1-3 days) were associated with larger improvement in posttest score; delivery format, specialty, and postgraduate year were not. Trainees reported an improvement in self-rated abilities to manage TM scenarios; 95% rated TM knowledge as very or extremely important in providing patient care; and 81% indicated that they had applied learning from Transfusion Camp into clinical practice. CONCLUSIONS Transfusion Camp increased TM knowledge, fostered a positive attitude toward TM, and enabled a self-reported positive impact on transfusion practice in postgraduate trainees. It is a novel and scalable approach to delivering TM education.

Aim To quantify circulating fibroblast activation protein (cFAP) and dipeptidyl peptidase 4 (cDPP4) protease activities in patients with rheumatoid arthritis (RA), systemic sclerosis (SSc), and a control group with mechanical back pain and to correlate plasma levels with disease characteristics. Methods Plasma was collected from patients with RA (n = 73), SSc (n = 37) and control subjects (n = 26). DPP4 and FAP were quantified using specific enzyme activity assays. Results Median cDPP4 was significantly lower in the RA group (P = 0.02), and SSc group (P = 0.002) compared with controls. There were no significant differences in median cFAP between the three groups. DPP4 and FAP demonstrated a negative correlation with inflammatory markers and duration of disease. There were no associations with disease subtypes in RA, including seropositive and erosive disease. Decreased cDPP4 was found in SSc patients with myositis. Plasma FAP was lower in RA patients receiving prednisone (P = 0.001) or leflunomide (P = 0.04), but higher with biologic agents (P = 0.01). RA patients receiving leflunomide also had decreased cDPP4 (P = 0.014). SSc patients receiving prednisone (P = 0.02) had lower cDPP4 but there was no association with cFAP. Conclusions No association was found between cFAP and RA or SSc. Plasma DPP4 was decreased in RA and SSc when compared with controls. cDPP4 and cFAP correlated negatively with inflammatory markers and there were no significant correlations with disease characteristics in this RA cohort.

The presence or absence of core fucose in the Fc region N-linked glycans of antibodies affects their binding affinity toward FcγRIIIa as well as their antibody-dependent cell-mediated cytotoxicity (ADCC) activity. However, the quantitative nature of this structure-function relationship remains unclear. In this study, the in vitro biological activity of an afucosylated anti-CD20 antibody was fully characterized. Further, the effect of fucose reduction on Fc effector functions was quantitatively evaluated using the afucosylated antibody, its "regular" fucosylated counterpart and a series of mixtures containing varying proportions of "regular" and afucosylated materials. Compared with the "regular" fucosylated antibody, the afucosylated antibody demonstrated similar binding interactions with the target antigen (CD20), C1q and FcγRIa, moderate increases in binding to FcγRIIa and IIb, and substantially increased binding to FcγRIIIa. The afucosylated antibodies also showed comparable complement-dependent cytotoxicity activity but markedly increased ADCC activity. Based on EC 50 values derived from dose-response curves, our results indicate that the amount of afucosylated glycan in antibody samples correlate with both FcγRIIIa binding activity and ADCC activity in a linear fashion. Furthermore, the extent of ADCC enhancement due to fucose depletion was not affected by the FcγRIIIa genotype of the effector cells.

OBJECTIVE. Anecdotal reports have suggested differences in children's tolerance to different intravenous immunoglobulin products; however, there has been little research on this issue. We sought to determine whether different intravenous immunoglobulin products used in the treatment of juvenile dermatomyositis are equally well tolerated by patients and, if not, whether differences in tolerance are linked to immunoglobulin A content. PATIENTS AND METHODS. The intravenous immunoglobulin infusion history (product given and history of adverse events) of patients who were attending the juvenile dermatomyositis clinic at the Hospital for Sick Children from 1986 to 2005 was reviewed. Products with an immunoglobulin A content of >15 μg/mL were classified as “high immunoglobulin A.” Data were analyzed by using logistic regression models adjusted for repeated measures. RESULTS. Thirty-eight patients with juvenile dermatomyositis received 1056 infusions at the Hospital for Sick Children. Adverse events were reported on 92 occasions (9%), affecting 25 patients (66%), a frequency that is higher than that usually reported in adult patients ( CONCLUSIONS.Intravenous immunoglobulin was found to be safe and well tolerated by most children with juvenile dermatomyositis. However, in contrast to adult studies, we found that significant differences existed in tolerance to different intravenous immunoglobulin products, most likely because of immunoglobulin A concentration. This study confirms anecdotal reports that a high level of immunoglobulin A in intravenous immunoglobulin is less well tolerated by children and provides evidence that product choice is important in pediatrics.

A combination of fluorescence-activated cell sorting and interphase fluorescence in situ hybridization (FISH) techniques was used to detect a clonal chromosomal marker in blasts, granulocytes, and T and B lymphocytes of the peripheral blood from a patient with Down syndrome and acute megakaryoblastic leukemia (AMKL) associated with trisomy 8 as a karyotypic abnormality. Immunophenotypic studies with flow cytometry showed two populations of leukemic blasts distinguished by their expression of the CD34 antigen. Interphase FISH studies revealed clonal trisomy 8 FISH signals in almost all blast cells, regardless of CD34 expression, as well as in a small subpopulation of granulocytes. Normal chromosome 8 signal patterns were detected in T and B cells and in a great majority of granulocytes. The present study provides evidence for the clonal involvement of leukemic blasts in AMKL of Down syndrome, indicating that a trisomy 8 abnormality may be a primary event in leukemogenesis. The transformation occurs in progenitor cells with limited myeloid differentiation and without involvement of lymphoid lineage cells.

Abstract 3021 Umbilical Cord Blood (UCB) is frequently used as a source of stem cells for children undergoing allogeneic hematopoietic stem cell transplant (HSCT) for both benign and malignant disorders. Despite algorithms using both nucleated cell numbers and HLA typing, the rate of engraftment failure remains higher than rates observed using other stem cell products. We conducted a retrospective review of our centre's experience with HSCT with UCB to evaluate the impact of herpesvirus viremia on the rate of engraftment. Children who underwent allogeneic HSCT with UCB between 06/2005 and 05/2010 inclusive were identified from the program database. Engraftment was defined as the first day of three consecutive absolute neutrophil counts of > 0.5 × 10[exp 9]/L within 42 days of UCB infusion and evidence of donor DNA on chimerism testing. Blood samples were sent for qualitative herpesvirus polymerase chain reaction (PCR) weekly (HHV-6, HHV-7, EBV, CMV, HSV or VZV). If either CMV or EBV results were positive, a quantitative assay was performed as well. Viremia was considered to have occurred if the qualitative assay became positive. Anti-viral therapy was initiated for measurable amounts of either CMV or EBV DNA or selectively for HHV-6 DNA. Eighty-one HSCT utilizing UCB were performed during this period. One child was unevaluable (NRM at day +15) so the analysis was performed using the remaining 80 patients. Thirty HSCT (37.5%) were performed for non-malignant indications and 50 (62.5%) for malignant disorders. Ninety per cent were performed using unrelated UCB; 27 were 6/6 HLA matched UCB, 42 were 5/6 HLA matches and 11 were 4/6 matches. Four children were recovering counts at day +42 but had not reached the threshold neutrophil value. They were considered as delayed engraftment rather than engraftment failure. Eleven (14%) failed to engraft. Forty-two (52.5%) of the transplants were complicated by the detection of 1 or more herpesviruses (24 for only 1 virus, 15 for 2 viruses and 3 for 3 viruses). None of gender, ABO matching, recipient CMV pre-HSCT serostatus, disease category, use of ATG or TBI in the conditioning regimen, use of methotrexate as GVHD prophylaxis or positivity for any single herpesvirus was associated with engraftment failure. Numbers of viable nucleated cells and CD34+ cells were not different between those that engrafted and those that failed to engraft. Transplants complicated by viremia of more than 1 herpesvirus had a significantly poorer engraftment rate than others (0.667 vs 0.933, P=0.007); more specifically viremia due to CMV and any other herpesvirus was associated with a worse engraftment rate than others (0.643 vs 0.921, P=0.006) (table). Notably viremia due to HHV-6 and others or EBV and others were not related to engraftment failure.PCR resultEngraftedFailed to engraftNo CMV516CMV positive185CMV alone90CMV plus: HHV-632 HHV-721 EBV22 HHV-6 & HHV-710 HHV-6 & EBV10 Conclusion: A significantly poorer engraftment rate in children undergoing HSCT using UCB was seen in those with CMV viremia in the presence of another herpesvirus. Further research is needed to define cause and effect and the therapeutic strategies to prevent it. Disclosures: No relevant conflicts of interest to declare.

Background: A multi-organ donor seronegative for hepatitis C virus (HCV) by 1st generation enzyme immunoassay (EIA) supplied 5 solid organs and 2 corneas to 7 recipients. This donor was retrospectively shown to be 2nd generation HCV EIA-positive and polymerase chain reaction (PCR)-positive. All 5 solid organ recipients but none of the corneal recipients developed HCV infection. Objectives: To demonstrate the discordance between serological and PCR-based HCV detection in solid organ transplant recipients and the lack of transmission of HCV to the two corneal transplant recipients. Study design: All 5 solid organ recipients were retrospectively shown to be HCV PCR-negative and -seronegative pre-transplant and HCV PCR-positive post-transplant. Serial serum samples on 3 recipients were evaluated by 2nd generation EIA, a prototypic structural and non-structural dual bead assay (EIA-SA, Abbott), the Chiron Recombinant Immunoblot Assay, 2nd generation (RIBA-2), and the Chiron RIBA HCV Test System Strip Immunoblot Assay 3.0 (RIBA-3, Chiron). Results: The dual bead EIA-SA and RIBA-3 were able to detect HCV seroconversion approximately 6 months earlier than the 2nd generation EIA in 2 recipients, and in 1 recipient only PCR detected infection within the first 10 months. There was no evidence of HCV transmission to the corneal recipients. Conclusions: Although third generation assays such as the RIBA-3 and EIA-SA narrowed the window of HCV seronegativity in transplant recipients compared with the 2nd generation EIA, PCR was the most sensitive method of detecting acute HCV infection. Despite transmission of HCV to all of the solid organ recipients HCV was not transmitted to the corneal transplant recipients.

Between June 1994 and December 2003, 31 patients with haematological disorders presenting at the Hospital for Sick Children, Toronto, Canada, received a stem cell transplant (SCT) from a mismatched related donor. Diagnoses included ALL (15), AML (10), CML (1), JMML (1), SAA (2), de novo MDS (1) and Fanconi anaemia (1). Patients were aged between 0.9 to 17.8 years (mean 8.5 years). There were 20 males and 11 females. HLA typing included A, B and DRB1 on all patients (Class 1 alleles by low resolution molecular technique and Class 2 by high resolution technique). 22 patients had 1 major mismatch and 9 had 2–3 major mismatches. The source of stem cells was bone marrow in 15 patients (mean total nucleated cell dose 4.44 x 108/kg, range 1.89–6.63), peripheral blood (PBSC) in 15 patients (mean CD34 dose 11.80 x 106/kg, range 3.19–42.18) and one patient received both BM and PBSC. Of those who received PBSC, 9 had CD34 selection, 3 had CD34 selection and T-cell depletion, and 3 received an unmodified product. Conditioning regimens included cyclophosphamide and total body irradiation (TBI) (15), etoposide and TBI (6), busulfan and cyclophosphamide (6), etoposide and cyclophosphamide (1), fludarabine, cyclophosphamide and TBI (1), fludarabine and cyclophosphamide (1) and fludarabine, melphalan and thiotepa (1). Graft versus host disease (GvHD) prophylaxis included combinations of cyclosporine A, methotrexate, anti-thymocyte globulin and methylprednisolone. There was one primary graft failure and 3 secondary graft failures. Mean time to neutrophil engraftment was 17 days (range 9–36). The incidence of acute and chronic GvHD was 48% and 51% respectively. Of the 31 patients, 15 are alive (12 in complete remission (one of these with a secondary brain tumour) and 3 with relapsed disease) and 16 are dead (3 of relapsed progressive disease, 12 from transplant related mortality (TRM - 9 of these were in CR) and in one the cause is not known). Three year actuarial OS and EFS for the entire group were 50±9% and 45±9%, OS and EFS for those matched at 5/6 loci were 56±11% and 44±11% and OS and EFS for 3/6 and 4/6 matched were 38±16% and 36±16%. The mean follow-up time for survivors is 5.6 years (range 11.6 months to 9.7 years). In this series, there was no significant difference in survival when comparing BM vs. PBSC harvests; in one vs. 2–3 mismatch donors; and in the presence vs. absence of acute or chronic GvHD. These results confirm the feasibility and efficacy of using mismatched related donors for paediatric haematological disorders. Steps should be taken to decrease the TRM to achieve a better survival rate.