Antibody incidence and red blood cell transfusions in patients on daratumumab.

BACKGROUND: Daratumumab (Dara), an anti-CD38 monoclonal antibody for hematologic malignancies, interferes with routine blood bank testing, specifically affecting the antibody screen and identification panels. In 2016, the AABB recommended performing a baseline phenotype or genotype before a patient (Pt) begins taking anti-CD38 to avoid this interference and potential problems with transfusion. The objective of this study was to assess red blood cell (RBC) utilization and subsequent incidence of alloimmunization to the transfused RBCs in patients receiving Dara. METHODS AND MATERIALS: We monitored 244 patients taking Dara to determine their red blood cell transfusions and incidence of clinically significant antibody formation before and following administration of Dara. Poisson generalized estimating equations with log link were used comparing the post-Dara incidence and prevalence to those prior, with significance defined as p < .05. RESULTS: From September 1, 2015 to December 22, 2018, 244 patients on Dara were identified, of which 145 patients (59.4%) received a red blood cell transfusion. Antibody screens were performed on 97 of the 145 patients at least 2 weeks following RBC transfusion. Four of the total transfused patients (2.8% total, 4.1% patients with follow-up antibody screen testing) formed new clinically significant alloantibodies, which was not significantly different from Asare's hematologic incidence (p = .98/p = .49). CONCLUSIONS: This study showed our patients on Dara did not form alloantibodies following RBC transfusion at a higher incidence than similar patient populations.

In from the cold: M-protein light chain glycosylation is positively associated with cold agglutinin titer levels.

BACKGROUND: Primary cold agglutinin disease (CAD) is a monoclonal antibody (M-protein) and complement-mediated chronic hemolytic disease process. Antibody glycosylation can play a role in both antibody half-life and complement fixation. Recently, M-protein light chain (LC) glycosylation has been shown to be associated with AL amyloidosis. We hypothesized that M-protein LC glycosylation is also associated with cold agglutinin (CA) titers and CA-mediated hemolysis. STUDY DESIGN AND METHODS: A cross-sectional study of patients undergoing CA titer evaluation underwent mass spectrometric analysis for M-proteins and M-protein LC glycosylation. A subset of serum samples also underwent evaluation for the ability to trigger cold hemolysis in vitro. M-protein and M-protein LC glycosylation rates were compared across CA titer groups, clinical diagnosis, direct antiglobulin testing (DAT) results, and cold in vitro hemolysis rates. RESULTS: Both M-protein and M-protein LC glycosylation rates significantly differed across CA titer groups with the highest rates in those with elevated CA titers. M-protein LC glycosylation occurred almost exclusively on IgM kappa M-proteins and was significantly associated with positive DAT results and a clinical diagnosis of CAD. Cold in vitro hemolysis was demonstrated in two patients who both had a CA titer of more than 512 but there was no significant association with CA titer group or M-protein LC glycosylation status. CONCLUSION: M-protein LC glycosylation is significantly associated with higher CA titer levels. Given the role that antibody glycosylation can play in antibody half-life and complement fixation, further studies are needed to clarify the effects of LC glycosylation within the context of CAD.

Hemolytic disease and reticulocytopenia of the newborn attributable to maternal immunoglobulin G anti-M reacting optimally at cold temperatures.

BACKGROUND: Hemolytic disease of the fetus and newborn (HDFN) attributable to anti-M is rare, although case reports implicate anti-M in varying severities of HDFN, including fetal hydrops and intrauterine death. CASE DESCRIPTION: We describe the case of a newborn with HDFN associated with an atypical immunoglobulin (Ig) G anti-M that reacted best at cold temperatures. The maternal antibody detected in pregnancy was not reactive at 37°C, and a direct antiglobulin test (DAT) on red blood cells (RBCs) from the newborn was negative, suggesting an anti-M that should not have been clinically relevant. However, the infant developed hyperbilirubinemia (bilirubin level, 17.6 mg/dL), hemolytic anemia (hemoglobin nadir, 5.5 g/dL), and reticulocytopenia. Laboratory testing demonstrated the presence of an IgG anti-M in maternal and neonatal samples reacting best at 4°C. This passively acquired IgG anti-M provoked hemolytic anemia in the infant and likely suppressed erythropoiesis, resulting in reticulocytopenia with prolonged anemia. He was treated for IgG anti-M HDFN with 10 intravenous Ig infusions and 10 days of oral prednisone followed by a taper. He required seven transfusions with M- RBCs. His hemoglobin level normalized at 3 months of age. Follow-up at 2 years revealed no hematologic or neuro-developmental concerns. CONCLUSION: To our knowledge, this is the second report of HDFN attributable to an IgG anti-M reacting preferentially at cold temperature with no 37°C reactivity. Clinically relevant IgG anti-M may elude standard testing. Early recognition and testing for cold-reacting IgG anti-M should be considered for newborns with hemolysis, a negative DAT, and prolonged anemia.

To Give or Not to Give: RhD Immunoglobulin for an RHD *39 Pregnant Woman with Sickle Cell Disease.

INTRODUCTION: Patients with sickle cell disease (SCD) have repeated episodes of red blood cell (RBC) sickling and microvascular occlusion that manifest as pain crises, acute chest syndrome, and chronic hemolysis. These clinical sequelae usually increase during pregnancy. Given the racial distribution of SCD, patients with SCD are also more likely to have rarer RBC antigen genotypes than RBC donor populations. We present the management and clinical outcome of a 21-year-old pregnant woman with SCD and an RHD*39 (RhD[S103P], G-negative) variant. CASE PRESENTATION: Ms. S is B positive with a reported history of anti-D, anti-C, and anti-E alloantibodies (anti-G testing unknown). Genetic testing revealed both an RHD*39 and homozygous partial RHCE*ceVS.02 genotype. Absorption/elution testing confirmed the presence of anti-G, anti-C, and anti-E alloantibodies but could not definitively determine the presence/absence of an anti-D alloantibody. Ms. S desired to undergo elective pregnancy termination and the need for postprocedural RhD immunoglobulin (RhIG) was posed. Given that only the G antigen site is changed in an RHD*39 genotype and the potential risk of RhIG triggering a hyperhemolytic episode in an SCD patient, RhIG was not administered. There were no procedural complications. Follow-up testing at 10 weeks showed no increase in RBC alloantibody strength. DISCUSSION/CONCLUSION: Ms. S represents a rare RHD*39 and partial RHCE*ceVS.02 genotype which did not further alloimmunize in the absence of RhIG administration. Her case also highlights the importance of routine anti-G alloantibody testing in women of childbearing age with apparent anti-D and anti-C alloantibodies.

How we provide thawed plasma for trauma patients.

Almost 50% of trauma-related fatalities within the first 24 hours of injury are related to hemorrhage. Improved survival in severely injured patients has been demonstrated when massive transfusion protocols are rapidly invoked as part of a therapeutic approach known as damage control resuscitation (DCR). DCR incorporates the early use of plasma to prevent or correct trauma-induced coagulopathy. DCR often requires the transfusion of plasma before determination of the recipient's ABO group. Historically, group AB plasma has been considered the "universal donor" plasma product. At our facility, the number of AB plasma products produced on an annual basis was found to be inadequate to support the trauma service's DCR program. A joint decision was made by the transfusion medicine and trauma services to provide group A thawed plasma (TP) for in-hospital and prehospital DCR protocols. A description of the implementation of group A TP into the DCR program is provided as well as outcome data pertaining to the use of TP in trauma patients.

Defining a reference range for cold agglutinin titers.

BACKGROUND: The cold agglutinin (CAGG) titer is offered at our institution to aid in diagnosing cold agglutinin disease (CAD). Our goal was to create a seasonally adjusted reference range using prospective samples and compare it to a reference range generated retrospectively. STUDY DESIGN AND METHODS: Prospective CAGG titer testing was performed on healthy blood donors. Retrospective electronic analysis was performed on patients in two groups defined by current and historical testing methods. Blood donor testing was performed in January and July to determine if seasonal variation existed. Retrospective patients with conditions associated with CAD were excluded from analysis. Additional prospective CAGG testing using reference range program volunteers was performed to verify blood donor and patient result differences. RESULTS: Titers from the blood donor and patient cohorts had no age association (p > 0.44). Titers from those same cohorts did not show winter/summer variation (p > 0.11). No sex association was found with titer reference ranges in the blood donor and historical patient cohort. A sex association was found with titers in the current method patient cohort (male 64 to 512 and female ≤64; p < 0.0001). Blood donor CAGG titer lower 95% reference range was not more than 4 while historical and current patient cohorts ranges were not more than 32 and not more than 64, respectively. Reference range volunteers confirmed the narrow reference range in healthy individuals when compared to patients and blood donors. CONCLUSION: Prospective blood donor CAGG titers were lower than retrospective patient cohorts. This may be due to blood donors representing a healthier population than the patient cohorts.

Clinically significant anti-A(1) in a presumed ABO-identical hematopoietic stem cell transplant recipient: a case report.

BACKGROUND: Subgroups of the blood group A (ABO) are generally not considered ABO incompatible for hematopoietic progenitor cell (HPC) transplant. CASE REPORT: A 54-year-old female presented for HPC transplantation for acute leukemia. No HLA-matched donor was identified, so she received a peripheral blood stem cell graft from an HLA-mismatched unrelated donor. On pretransplant testing, both the donor and the recipient typed as blood group A. On Day +67 after transplant, the recipient had a transfusion reaction consisting of an increase in temperature, rigors, and shaking chills during infusion of a unit of group A red blood cells (RBCs). A transfusion reaction workup revealed an ABO discrepancy with both anti-A (1+) and anti-B (3+) identified in the patient's serum as well as a positive direct antiglobulin test with monoclonal anti-IgG antisera. Anti-A(1) were identified serologically and in an eluate. Hemolysis was clinically significant, requiring blood transfusion. No ABO typing discrepancies were found on pretransplant testing in either the recipient or the donor. DNA sequencing for blood group A subgroups performed after the transfusion reaction on blood collected before the transplant showed the donor to be type A(1) and the recipient as A(2) . Unfortunately, the patient experienced graft failure requiring reconditioning and reinfusion of additional cells from the original HPC donor. On Day +94 after the second transplant, the patient died with severe acute gastrointestinal graft-versus-host disease. CONCLUSION: This report describes a blood group A(2) patient who developed an anti-A(1) causing clinically significant hemolysis after HPC transplant from an A(1) donor.

Polyethylene glycol antiglobulin tube versus gel microcolumn: influence on the incidence of delayed hemolytic transfusion reactions and delayed serologic transfusion reactions.

BACKGROUND: Our institution has reported on delayed hemolytic transfusion reaction (DHTR) and delayed serologic transfusion reaction (DSTR) incidence changes. From January 1993 to June 2003, a polyethylene glycol (PEG) tube-based technique was used for red blood cell (RBC) antibody screen. In June 2003, a gel microcolumn technique was implemented. Impact of this on antibody detection and DHTR and DSTR incidence was investigated. STUDY DESIGN AND METHODS: Positive antibody screen frequency and antibody specificity from January 2002 to March 2003 and July 2003 to September 2004 were compared. Overall incidence of DHTR and DSTR as well as the number and identity of the RBC antibodies implicated from August 1999 through June 2003 (PEG) and July 2003 through July 2007 (gel) were compared. The mean length of hospital stay (LOS) and number of RBC units transfused per patient were compared. RESULTS: Equivalent numbers of antibody screens were performed with equivalent numbers of positive screens. Significant differences were not seen in the detection of clinically significant antibodies but significantly fewer clinically insignificant antibodies were detected with gel. Ninety-six DHTRs and DSTRs were diagnosed. The LOS and number of transfused RBC units were not statistically different. A significantly higher incidence of DHTRs and DSTRs was seen with PEG compared to the gel. CONCLUSION: The gel microcolumn method is similar to the PEG in detecting clinically significant antibodies but detects fewer clinically insignificant antibodies. The implementation of gel resulted in a lower incidence of DHTRs and DSTRs compared to PEG.

Toward extended phenotype matching: a new operational paradigm for the transfusion service.

BACKGROUND: Conventional pretransfusion testing uses hemagglutination to ensure donor-recipient compatibility for ABO/D status and recipient alloantibodies. While screening large numbers of donor units for multiple antigens by hemagglutination is impractical, novel methods of DNA analysis permit the rapid determination of an extended human erythrocyte antigen (xHEA) phenotype. A prospective observational study was conducted at four hospital transfusion services to test an alternative paradigm of identifying xHEA-typed units for patients in three cohorts by utilizing DNA analysis and a novel inventory management model. STUDY DESIGN AND METHODS: xHEA typing of recipient samples and donor units of known ABO/D status was performed by HEA analysis (BeadChip, BioArray Solutions). xHEA-typed units were assigned to pending transfusion requests using an inventory management system designed to simulate blood order processing. The fraction of requests fulfilled, or "fill fraction" (FF) was determined at four levels of matching stringency. RESULTS: For alloimmunized patients, all but one participating site observed an FF of more than 95% when matching for ABO, D, and known alloantibodies and an FF of more than 90% when additionally matching for C, c, E, e, and K; the site handling the most challenging requests still observed FFs of 62 and 51%, respectively. FF was found to correlate positively with the ratio of available donor units to units requested and negatively with the degree of recipient alloimmunization. CONCLUSION: This study demonstrates that substantial fill fractions can be achieved by selecting existing donor units for xHEA analysis and operating an inventory management system for efficient allocation of units to recipients.

Does Transfusion of Red Blood Cells Impact Germline Genetic Test Results?

PURPOSE: molecular testing is often indicated for recently transfused patients. However, there are no guidelines regarding the potential interference from donor DNA or whether it is necessary to wait for a period of time post-transfusion prior to genetic testing. While the majority of patients are transfused in the non-trauma setting using leukoreduced (LR) red blood cell products, the degree of leukoreduction varies among centers and is not universally practiced. METHODS: whole blood units collected from anonymous donors were used in an in vitro transfusion model. One unit was split: half being leukoreduced simulating a leukopenic recipient and half left untreated. Donors were simulated by leukoreduced, partially leukoreduced (PLR), or non-leukoreduced units, transfused in 2, 5, or 16 unit equivalents. DNA from the combinations were subjected to short tandem repeat (STR) analysis for chimerism detection. RESULTS: donor DNA was not detectable in any of the LR combinations, but detected in the PLR combinations, ranging from 0.1 to 1.5% donor DNA in the immunocompetent recipient and 6.3-27.8% in the leukopenic recipient. Non-LR donor DNA was also detected (13-95%). CONCLUSION: donor-derived DNA from leukoreduced blood products is unlikely to interfere with the interpretation of germline genetic testing in immunocompetent recipients but may interfere in immunocompromised recipients.

Eluate testing following microscopically positive direct antiglobulin tests with anti-IgG.

The direct antiglobulin test (DAT) demonstrates the presence of immunoglobulin (eg, IgG) or complement on the surface of red blood cells (RBCs). Immunoglobulin can be removed from RBCs by elution. The liquid end-product of elution procedures, the eluate, can be evaluated by antibody identification procedures. Antibody identification studies following acid/EDTA elution and DATs performed in our immunohematology laboratory during 2005 were evaluated to determine the usefulness of eluate testing following a microscopically positive IgG DAT. In total, 310 eluates were prepared during the year 2005; 146 of these eluates were derived from RBC samples with a microscopically positive DAT. The remaining eluates were derived from RBC samples with macroscopically positive IgG DATs (85 were weakly +; 32 were 1+; 40 were 2+; and 7 were 3+). Data were collected for the number and types of new antibodies (warm autoantibodies or alloantibodies) that were identified as a consequence of eluate testing. The incidence of new alloantibodies in the microscopically positive group (0.7%) was significantly lower than the combined incidence in the macroscopically positive groups (5.5%, p = 0.02). Based on these results, the authors conclude that performing antibody identification procedures on acid/EDTA eluates derived from RBC samples with microscopically positive IgG DATs has limited utility.

Non-O blood type is associated with an increased risk of venous thromboembolism after radical cystectomy.

OBJECTIVE: To evaluate the association of blood type (non-O vs O) with venous thromboembolism (VTE) risk after radical cystectomy (RC) for bladder cancer. METHODS: From 1980 to 2005, we identified 2076 consecutive patients with RC for whom blood type was available in 2008 (96.7%). We evaluated the association of blood type with postoperative VTE using logistic regression, controlling for patient age, tumor, and nodal stage, Eastern Cooperative Oncology Group (ECOG) performance status, body-mass index (BMI), and number of lymph nodes removed at surgery. RESULTS: A total of 865 of 2076 patients (41.7%) had O blood type, 1143 (55.0%) were non-O, and 68 (3.3%) were missing. Median follow-up was 11.1 years, during which time VTE developed in 216 patients (10.4%). No significant differences were noted between those with O vs non-O blood type regarding patient age (median 69 years vs 69, P = .87), ECOG (P = .69), BMI (median 27.5 vs 28.1, P = .12), tumor stage (P = .97), pN+ status (15.6% vs 15.2%, P = .79), or number of nodes removed (median 9 vs 8, P = .43). On multivariate analysis, non-O blood type was associated with a nearly two-fold increased risk of VTE (odds ratio [OR] = 1.85, P = .007). CONCLUSION: Non-O blood type was independently associated with an increased risk of VTE after RC. These patients should be counseled accordingly, and may benefit from increased perioperative prophylaxis.

Red blood cell phenotype matching for various ethnic groups.

Patients requiring chronic transfusion support are at risk of alloimmunization after red blood cell (RBC) transfusion because of a disparity between donor and recipient antigen profiles. This research explored the probability of obtaining an exact extended phenotype match between blood donors randomly selected from our institution and patients randomly selected from particular ethnic groups. Blood samples from 1,000 blood donors tested by molecular method were evaluated for the predicted phenotype distribution of Rh, Kell, Kidd, Duffy, and MNS. A random subsample of 800 donor phenotypes was then evaluated for the probability of obtaining an exact match with respect to phenotype with a randomly selected patient from a particular ethnic group. Overall, there was a greater than 80 percent probability of finding an exact donor-recipient match for the K/k alleles in the Kell system. The probability ranged from 3 percent to 38 percent, depending on the ethnicity and disparities in phenotypic profiles, for the Rh, Kidd, Duffy, and MNS systems. A significant donor-recipient phenotype mismatch ratio exists with certain blood group antigens such that, with current routine ABO and D matching practices, recipients of certain ethnic groups are predisposed to alloimmunization.