Recombinant ADAMTS13 for Immune Thrombotic Thrombocytopenic Purpura.

In patients with immune thrombotic thrombocytopenic purpura (iTTP), autoantibodies against the metalloprotease ADAMTS13 lead to catastrophic microvascular thrombosis. However, the potential benefits of recombinant human ADAMTS13 (rADAMTS13) in patients with iTTP remain unknown. Here, we report the clinical use of rADAMTS13, which resulted in the rapid suppression of disease activity and complete recovery in a critically ill patient whose condition had proved to be refractory to all available treatments. We also show that rADAMTS13 causes immune complex formation, which saturates the autoantibody and may promote its clearance. Our data support the role of rADAMTS13 as a novel adjunctive therapy in patients with iTTP.

Severe autoimmune hemolytic anemia following receipt of SARS-CoV-2 mRNA vaccine.

BACKGROUND: Large clinical trials have demonstrated the overall safety of vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, reports have emerged of autoimmune phenomena, including vaccine-associated myocarditis, immune thrombocytopenia, and immune thrombotic thrombocytopenia. CASE PRESENTATION: Here we present a novel case of a young woman who developed life-threatening autoimmune hemolytic anemia (AIHA) after her first dose of a SARS-CoV-2 mRNA vaccine. Notably, initial direct antiglobulin testing was negative using standard anti-IgG reagents, which are "blind" to certain immunoglobulin (IgG) isotypes. Further testing using an antiglobulin reagent that detects all IgG isotypes was strongly positive and confirmed the diagnosis of AIHA. The patient required transfusion with 13 units of red blood cells, as well as treatment with corticosteroids, rituximab, mycophenolate mofetil, and immune globulin. CONCLUSION: As efforts to administer SARS-CoV-2 vaccines continue globally, clinicians must be aware of potential autoimmune sequelae of these therapies.

An open-source python library for detection of known and novel Kell, Duffy and Kidd variants from exome sequencing.

BACKGROUND AND OBJECTIVES: Next generation sequencing (NGS) has promising applications in transfusion medicine. Exome sequencing (ES) is increasingly used in the clinical setting, and blood group interpretation is an additional value that could be extracted from existing data sets. We provide the first release of an open-source software tailored for this purpose and describe its validation with three blood group systems. MATERIALS AND METHODS: The DTM-Tools algorithm was designed and used to analyse 1018 ES NGS files from the ClinSeq® cohort. Predictions were correlated with serology for 5 antigens in a subset of 108 blood samples. Discrepancies were investigated with alternative phenotyping and genotyping methods, including a long-read NGS platform. RESULTS: Of 116 genomic variants queried, those corresponding to 18 known KEL, FY and JK alleles were identified in this cohort. 596 additional exonic variants were identified KEL, ACKR1 and SLC14A1, including 58 predicted frameshifts. Software predictions were validated by serology in 108 participants; one case in the FY blood group and three cases in the JK blood group were discrepant. Investigation revealed that these discrepancies resulted from (1) clerical error, (2) serologic failure to detect weak antigenic expression and (3) a frameshift variant absent in blood group databases. CONCLUSION: DTM-Tools can be employed for rapid Kell, Duffy and Kidd blood group antigen prediction from existing ES data sets; for discrepancies detected in the validation data set, software predictions proved accurate. DTM-Tools is open-source and in continuous development.

Secondary bacterial culture of platelets to mitigate transfusion-associated sepsis: A 3-year analysis at a large academic institution.

BACKGROUND: In 2019, the United States Food and Drug Administration published its final recommendations to mitigate bacterial contamination of platelets. We sought to evaluate our secondary bacterial culture (SBC) strategy in light of those recommendations. STUDY DESIGN AND METHODS: A retrospective analysis was conducted of SBC data (October 2016-2019) at our institution. SBC was performed upon receipt (Day 3 after collection); 5 mL of platelet product was inoculated aseptically into an aerobic bottle and incubated at 35°C for 3 days. For 8 months, a 10-mL inoculum was trialed. No quarantine was applied. All positive cultures underwent Gram staining and repeat culture of the platelet product (if available). A probable true positive was defined as concordant positive culture between the initial and repeat culture. The incidence of probable true- and false-positive cultures were reported descriptively and differences evaluated by sampling volume. RESULTS: Over 3 years, 55 896 platelet products underwent SBC, yielding 30 initial positive results (approx. 1/1863 platelets); 25 (83.3%) signaled within 24 hours of SBC. The rates of probable true positive, false positive, and indeterminate for 5 mL were 0.027% (1/3771), 0.002% (1/45 251) and 0.018% (1/5656), respectively. The respective rates for 10 mL were 0.018% (1/5323), 0.07% (1/1521), and 0%. Seven of eight (87.5%) false-positive SBCs occurred with a 10-mL inoculum. No septic transfusion reactions were reported. CONCLUSION: SBC continues to interdict bacterially contaminated units of platelets. Our findings suggest higher rates of false positivity using large-volume inocula.

Banking with precision: transfusion medicine as a potential universal application in clinical genomics.

PURPOSE OF REVIEW: To summarize the most recent scientific progress in transfusion medicine genomics and discuss its role within the broad genomic precision medicine model, with a focus on the unique computational and bioinformatic aspects of this emergent field. RECENT FINDINGS: Recent publications continue to validate the feasibility of using next-generation sequencing (NGS) for blood group prediction with three distinct approaches: exome sequencing, whole genome sequencing, and PCR-based targeted NGS methods. The reported correlation of NGS with serologic and alternative genotyping methods ranges from 92 to 99%. NGS has demonstrated improved detection of weak antigens, structural changes, copy number variations, novel genomic variants, and microchimerism. Addition of a transfusion medicine interpretation to any clinically sequenced genome is proposed as a strategy to enhance the cost-effectiveness of precision genomic medicine. Interpretation of NGS in the blood group antigen context requires not only advanced immunohematology knowledge, but also specialized software and hardware resources, and a bioinformatics-trained workforce. SUMMARY: Blood transfusions are a common inpatient procedure, making blood group genomics a promising facet of precision medicine research. Further efforts are needed to embrace transfusion bioinformatic challenges and evaluate its clinical utility.

Sociodemographic and behavioral characteristics associated with blood donation in the United States: a population-based study.

BACKGROUND: Contemporary population-based data on characteristics associated with blood donation in the United States (U.S.) are limited. STUDY DESIGN AND METHODS: A cross-sectional analysis was performed among 28,739 persons aged 18 years and older who participated in the 2016 National Health Interview Survey, a household survey of the noninstitutionalized U.S. civilian population. Analyses were weighted and accounted for the complex survey design. Adjusted prevalence ratios (aPR) were estimated by multivariable log-binomial regression. RESULTS: The percentage of individuals reporting a past-year history of blood donation was 5.7% (95% confidence interval [CI], 5.3%-6.1%) and was highest in the youngest age group (18-24 years, 8.4%). A past-year history of blood donation was more common in males compared to females (6.3% vs. 5.1%; aPR, 1.12 [95% CI, 0.99-1.27]) and those born in the U.S. compared to individuals born outside the U.S. (6.4% vs. 2.4%; aPR, 1.92 [95% CI, 1.49-2.47]). The percentage of individuals with a past-year history of blood donation was significantly lower in blacks (3.9%; aPR, 0.60 [95% CI, 0.47-0.75]) and Hispanics (3.0%; aPR, 0.63 [95% CI, 0.48-0.83]) in comparison to whites (6.9%). Being a college graduate, being employed, being physically active, and never being a cigarette smoker were factors positively associated with blood donation. The percentage of individuals with a past-year history of blood donation varied by geographic census region, with prevalence being higher in the Midwest (7.3%) and South (6.0%) compared to the Northeast (4.7%) and West (4.4%). CONCLUSION: Continued differences in the blood donor population with reference to the U.S. population underscore the need to understand barriers or deterrents to blood donation. Evidence-based donor recruitment and related policies remain imperative to ensure that there is a sustainable blood supply.

Association of blood donation with iron deficiency among adolescent and adult females in the United States: a nationally representative study.

BACKGROUND: Blood donation results in a loss of iron stores, which is particularly concerning for young female blood donors. This study examines the association of blood donation and iron deficiency among adolescent and adult females in the United States. STUDY DESIGN AND METHODS: A cross-sectional analysis was performed using data from the 1999-2010 National Health and Nutrition Examination Survey (NHANES). Females who reported their blood donation history in the preceding year and had serum ferritin (SF) measurements were included. Analyses were weighted and stratified by adolescents (16-19 years; n = 2419) and adults (20-49 years; n = 7228). Adjusted prevalence ratios (aPRs) were estimated by multivariable Poisson regression. Standard errors were estimated by Taylor series linearization. RESULTS: Geometric mean SF levels (ng/mL) were lower in blood donors compared to nondonors among adolescents (21.2 vs. 31.4; p < 0.001) and among adults (26.2 vs. 43.7; p < 0.001). The prevalence of absent iron stores (SF < 12 ng/mL) was higher in blood donors compared to nondonors among adolescents (22.6% vs. 12.2%; aPR = 2.03 [95% confidence interval (CI) = 1.45-2.85]) and among adults (18.3% vs. 9.8%; aPR = 2.06 [95% CI = 1.48-2.88]). Additionally, the prevalence of iron deficiency anemia (SF < 26 ng/mL and hemoglobin < 12.0 g/dL) was also higher in blood donors compared to nondonors among adolescents (9.5% vs. 6.1%; aPR = 2.10 [95% CI = 1.13-3.90]) and among adults (7.9% vs. 6.1%; aPR = 1.74 [95% CI = 1.06-2.85]). Similar results were observed in a sensitivity analysis restricted to adolescents aged 16 to 18 years. CONCLUSIONS: Blood donation is associated with iron deficiency among adolescent and adult females in the United States. These national data call for further development and implementation of blood donation practices aimed toward mitigating iron deficiency.

An update on the Scianna blood group system.

CONCLUSIONS: This update of the Scianna blood group system (Brunker PA, Flegel WA. Scianna: the lucky 13th blood group system. Immunohematology 2011;27:41-57) provides the recent work on the genetic variation of ERMAP across more world populations, the elucidation of the molecular basis of an historical serologic case, new cases of antibodies in the system, the development of new serologic reagents, and new discoveries in the biology of the erythroid membrane associated protein (ERMAP). Although genetic variation in ERMAP has been extensively cataloged, nonsynonymous variants associated with alloantigens have remained limited, and no new antigens have been identified. The first case of a severe hemolytic transfusion reaction to anti-Sc2 has recently been reported, highlighting the importance of pursuing the possibility of antibodies to low-prevalence antigens via indirect antiglobulin testing as a routine component of all transfusion reaction investigations. The expanding use of molecular testing in blood centers and transfusion services has uncovered a wider population distribution of Scianna antigens and heightened the awareness of this blood group system. The International Society of Blood Transfusion recognizes seven antigens in the Scianna blood group system 13.

Hemostatic profile and safety of pooled cryoprecipitate up to 120 hours after thawing.

BACKGROUND: AABB standards state that cryoprecipitate should be transfused within 4 to 6 hours after thawing. We evaluated coagulation factor levels and sterility of thawed pooled cryoprecipitate to assess whether shelf life can be safely extended. STUDY DESIGN AND METHODS: Donor cryoprecipitate pools (n = 20, 10 group A, 10 group O) were held at ambient temperature and sampled at 0, 4, 8, 24, 48, 72, 96, and 120 hours post-thawing for fibrinogen, Factor (F)VIII, and von Willebrand factor (vWF) levels. Samples were tested at 0 and 120 hours for sterility (BacT/Alert system). Sixty additional cryoprecipitate pools were evaluated after 72 hours. Longitudinal differences in component levels were determined by linear fixed-effects regression. RESULTS: Group O cryoprecipitate had significantly lower FVIII (p = 0.002) and vWF activity (p = 0.006) compared to group A at 0 hours, but were not statistically different in fibrinogen levels (p = 0.33). Fibrinogen levels were stable over 5 days: 501 ± 81 mg/unit (mean ± standard deviation) at 0 hours to 506 ± 102 mg/unit at 120 hours (p = 0.73). Similarly, there was no decline in vWF activity: 200 ± 53 IU/unit at 0 hours to 209 ± 57 IU/unit at 120 hours (p = 0.084). The FVIII activity significantly declined on average by 9.6 IU (95% confidence interval, 5.5-13.8) between 0 hours (111 ± 33 IU/unit) and 120 hours post-thaw (101 ± 33) (p < 0.001). No organisms were detected when cryoprecipitate pools were cultured at 0 hours, but at 120 hours Staphylococcus epidermidis was identified from one pool, potentially a contaminant introduced during repeated sampling. No cultures were positive among the 60 additional cryoprecipitate pools assessed at 72 hours. CONCLUSION: Extended cryoprecipitate storage at ambient temperature did not affect fibrinogen levels over 120 hours. Sterility of products held at ambient temperature for an extended period of time could be assessed by secondary culture.

Modeling alloantibody formation to high-incidence red blood cell antigens in immune responders using genotypic data.

CONCLUSIONS: Alloimmunization to red blood cell antigens is unpredictable and poorly understood. Patients who are negative for high-incidence antigens (HIAs) are at risk for developing the corresponding antibodies. Molecular methods can easily predict the lack of an antigen and thus, the risk of an individual to become immunized. We examined the prevalence and risk factors for HIA alloimmunization in patients at risk based on genotyping results. Genotyping using a molecular method (HEA BeadChip™, Immucor, Warren, NJ) was performed on all patient specimens referred for molecular testing over 45 months; serologic and clinical data were analyzed. We used simple and multiple logistic regression to model the risk factors for alloimmunization to an HIA. Of the 2591 patients genotyped, 32 (1.2%) were homozygous for at least one variant predicting absence of an HIA. Of these 32 patients, prior transfusion or pregnancy history was available for 29 (91%). Four susceptible patients made an antibody to an HIA (12.5% of all, 13.8% of those with a documented exposure). Two of these four patients (50%) had made an alloantibody to another antigen. The odds of forming an antibody to an HIA were not related to the total number of transfusions (p = 0.47), the total number of alloantibodies (p = 0.61), or diagnosis of sickle cell disease (p = 0.77) in simple logistic regression. Adjustment for the other two variables in a multiple logistic regression was also not significant for each variable (p = 0.6, p = 0.7, and p = 0.7, respectively). Although they had a known exposure to alloantigens through transfusion or pregnancy, 86.2 percent of patients (25 of 29) at risk for alloantibody formation to an HIA in fact did not mount an immune response to that antigen. Possible risk factors including the number of transfused units or the total number of alloantibodies made were not predictors of making an alloantibody to an HIA in our sampling. Our results suggest that other patient-specific risk factors for alloimmunization exist.

Auditing plasma transfusion in intensive care: Use of decision time interval analysis.

OBJECTIVES: To present a new method for displaying blood utilization data based on analysis of decision time intervals (DTIs). METHODS: Retrospective study of patients treated in a medical intensive care unit (ICU), surgical ICU, or postcardiac surgery ICU at an academic hospital between January 2018 and June 2023. Each patient's episode of care was divided into a series of DTIs. Transfusions during each time interval were recorded. RESULTS: In total, 16,562 patients received 6980 units of plasma and 21,034 units of red blood cells during 111,557 time intervals of care. Patients had international normalized ratio (INR) values ranging from less than 1.0 to more than 4.0. Data on plasma transfusion at different INR values were displayed as the number of transfusion episodes, number of units given, or the proportion of DTIs with transfusion. Clinicians transfused plasma on 1.5% of occasions when the INR was 1.5 or less and on 2.2% of occasions when the INR was less than 2.0. Plasma was transfused without red blood cells in only 0.75% of DTIs. Transfusion practice was statistically different among the 3 ICUs. CONCLUSIONS: Compared with traditional methods of displaying the results of blood audits, DTI analysis displays information regarding the decision both to transfuse and to not transfuse. Utilization reviews that display data based on decision time analysis reveal clinical practice patterns very different from those suggested by traditional displays of plasma audit data.

Tumor cell-based liquid biopsy using high-throughput microfluidic enrichment of entire leukapheresis product.

Circulating Tumor Cells (CTCs), interrogated by sampling blood from patients with cancer, contain multiple analytes, including intact RNA, high molecular weight DNA, proteins, and metabolic markers. However, the clinical utility of tumor cell-based liquid biopsy has been limited since CTCs are very rare, and current technologies cannot process the blood volumes required to isolate a sufficient number of tumor cells for in-depth assays. We previously described a high-throughput microfluidic prototype utilizing high-flow channels and amplification of cell sorting forces through magnetic lenses. Here, we apply this technology to analyze patient-derived leukapheresis products, interrogating a mean blood volume of 5.83 liters from patients with metastatic cancer, with a median of 2,799 CTCs purified per patient. Isolation of many CTCs from individual patients enables characterization of their morphological and molecular heterogeneity, including cell and nuclear size and RNA expression. It also allows robust detection of gene copy number variation, a definitive cancer marker with potential diagnostic applications. High-volume microfluidic enrichment of CTCs constitutes a new dimension in liquid biopsies.

Blood Group Serology and "Race": Looking Back to Move Forward.

Less than a decade after the discovery of the ABO antigens as a Mendelian inherited trait, blood group antigen frequencies were first used to define racial groups. This approach, known as seroanthropology, was the basis for collecting large amounts of blood group frequency data in different populations and was also sometimes used for racist purposes. Ultimately, population geneticists used these data to disprove race as a biological construct. Through understanding the history of seroanthropology, and recognizing the harms of its lingering presence, healthcare providers can better practice race-conscious, as opposed to race-based, transfusion medicine.

Convalescent transfusion for pandemic influenza: preparing blood banks for a new plasma product?

Due to the potential of a severe pandemic to limit efficacy or availability of medical countermeasures, some researchers have begun a search for new interventions that could complement the planned antiviral- and vaccine-based response to an influenza pandemic. One such countermeasure-the transfusion of pandemic influenza-specific antibodies from surviving patients to the clinically ill-is the focus of this commentary. Passive immunotherapy, which includes the use of monoclonal antibodies (MoAbs), hyperimmune globulin, or convalescent plasma, had been used before the advent of antibiotics and has recently reentered the limelight due to the accelerating development of MoAb therapies against cancer, a number of microbes, allograft rejection, and a host of other conditions. After the plausible biologic mechanism and somewhat limited data supporting the efficacy for this modality against influenza are reviewed, safety and logistical concerns for utilization of this potential new product (fresh convalescent plasma against influenza [FCP-Flu]) are discussed. FCP-Flu could indeed prove useful in a response to a pandemic, but two necessary items must first be satisfied. Most importantly, more research should be conducted to establish FCP-Flu efficacy against the current and other pandemic strains. Second, and also importantly, blood banks and donor centers should examine whether offering this new product would be feasible in a pandemic and begin planning before a more severe pandemic forces us to respond without adequate preparation.

Chimerism in transfusion medicine: the grandmother effect revisited.

Transfusion therapy is complicated by the production of alloantibodies to antigens present in the donor and lacking in the recipient through the poorly-understood but likely multi-factorial process of alloimmunization. The low prevalence of alloimmunization in transfused patients (6.1%) (1) suggests that processes central to immunologic tolerance may be operating in the vast majority of transfused patients who do not produce alloantibodies. Using RhD as a prototype, evidence is reviewed that the ability to make antibodies to red blood cell (RBC) antigens may result in part from immunologic tolerance acquired in utero. These ideas are extended to other examples of maternal microchimerism (MMc) of other non-inherited maternal antigens (NIMA). An evolutionary argument is offered that multi-generational immunity supports the hypothesis that MMc may partly explain the "non-responder" phenotype in RBC alloimmunization.