Trends in antigen-negative red blood cell distributions by racial or ethnic groups in the United States

Optimizing transfusion management of multiple myeloma patients receiving daratumumab-based regimens

BACKGROUND

Daratumumab, a human anti-CD38 monoclonal antibody used to treat multiple myeloma, interferes with pretransfusion testing and can mask alloantibodies. Incidence of alloimmunization in patients on daratumumab has not been well characterized, and optimal transfusion guidelines regarding prophylactic antigen matching, accounting for both patient safety and efficiency, have not been well established for these patients.

METHODS

Records of patients who received daratumumab between January 1, 2014 and July 2, 2019 were reviewed. Daratumumab interference with pretransfusion testing was managed by testing with reagent red blood cells (RBCs) treated with 0.2 M dithiothreitol. When daratumumab was present during antibody testing, patients were transfused with RBC units prophylactically matched for D, C, c, E, e, and K antigens per hospital policy.

RESULTS

Out of 90 patients identified, 52 received a total of 638 RBC transfusions (average of 12.3 units per patient, SD 17.2, range 1-105, median 5 among those transfused). Alloantibodies existing before daratumumab initiation were identified in seven patients. No new alloantibodies were detected in any patients after starting daratumumab treatment.

CONCLUSIONS

The incidence of alloimmunization in patients receiving daratumumab is low. Whether this is due to the effect of daratumumab, underlying pathophysiology, or other factors, is unknown. Because these patients require a large number of RBC transfusions overall and have little observed alloimmunization, phenotype matching (beyond RhD) may be unnecessary. Since the use of dithiothreitol cannot rule out the presence of anti-K, we recommend transfusion of ABO-compatible units, prophylactically matched for the D and K antigens only.

Adapting to supply-and-demand emerging trends for antigen-negative red blood cell units

BACKGROUND

A global downtrend in blood usage has been observed by many countries, while the demand for antigen-negative red blood cell (RBC) units used in antigen-matched transfusions keeps increasing. The declining number of units collected exposes blood providers to a rapidly evolving supply challenge.

METHODS

This study was conducted retrospectively with use of internal data analysis to weigh Québec's situation regarding global and antigen-negative RBC demand, to measure the effects of community-directed recruitment and blood drives, and to evaluate the benefits of mass-scale RBC genotyping.

RESULTS

Our findings confirm a global RBC usage downtrend of over 20% total in the past 10 years with a steady antigen-negative usage and highlight the most requested negative antigen combinations. Our data also show our +39.5% progress regarding the number of Black donors recruited for antigen matching of patients with sickle cell disease in the past 3 years, as well as a constantly growing number of just-in-time blood collection for complex orders. Finally, our data summarize the efficiency of our mass-scale RBC genotyping efforts.

CONCLUSION

Altogether, this study confirms the demand trends for regular and antigen-negative RBC units in Québec and the efficient effects of our recruitment and typing strategies.

Red cell genotyping of rare blood donors: donation behaviour and data visualization

BACKGROUND

The continual identification of rare blood among donors is critical to support national programs like the American Rare Donor Program (ARDP). Some blood centres require consent from donors to be registered with a national registry. This situation provides an opportunity to determine whether a donor's willingness to register is associated with a change in donation behaviour.

METHODS

Rare donors were identified by molecular typing. The average number of donations per year was compared for each donor prior to and after receiving a consent letter. Donors were categorized as either accepting or declining the request. Non-parametric t tests compared the statistical significance within and between categories. Rare types were overlaid with consensus data to look for trends using data visualization techniques.

RESULTS

A total of 270 molecularly typed rare donors received letters over 4 years. Half of the donors (132, 49%) agreed to participate in the ARDP. Overall, donation frequency increased after the letter when enrolled. Both Caucasian and non-Caucasian donors increased their donations after enrolling providing an additional 159 red blood cell units over 3 years. Declining participation did not change donation frequency. Data visualization showed that enrolled donors were more affluent, high school and college educated, and lived in their home for longer periods of time.

CONCLUSION

A donor's willingness to enrol in the ARDP was associated with a post-response increase in donation frequency. New interventions to reach non-Caucasian donors may be a prerequisite to increase donation frequency and a willingness to be a rare blood donor.

Unrecognized Hemoglobin Variants in the Donor Blood Supply Are Detectable in the Transfused Population

OBJECTIVES

The US Food and Drug Administration requires donated blood to be tested for various infectious diseases to ensure safety and purity. However, testing for hemoglobin variants is not required, despite reported occurrences of hemoglobin variant transfusion and concerns about the safety of such transfusions. This study aimed to investigate the frequency of hemoglobin variants within the blood supply.

METHODS

We performed a 2-part study. First, we tested all RBC units in our blood bank by high-performance liquid chromatography for the presence of hemoglobin variants. Second, we performed a retrospective analysis of hemoglobin variant testing completed for routine management of sickle cell disease patients at our institution over a 5-month period to identify cases of hemoglobin variant transfusion.

RESULTS

We found that 2 of 476 (0.4%) RBC units in our blood bank contained a hemoglobin variant, and 5 of 563 (0.9%) sickle cell patients seen at our institution in a 5-month period were transfused with RBCs containing a hemoglobin variant.

CONCLUSIONS

We confirmed that hemoglobin variants are present within the blood supply, and the frequency of hemoglobin variant transfusion is elevated for patients with sickle cell disease given the increased prevalence of hemoglobin variants in the population of matched donors.

Interventions to Increase Blood Donation among Ethnic/Racial Minorities: A Systematic Review

Ethnic/racial minorities are under-represented in blood donor populations in most developed countries. This is of particular concern where minorities differ from a country's majority population in terms of blood or tissue typing, especially where type matching is required for effective management of rare disorders such as sickle-cell disease that require multiple transfusions. This systematic review assessed the effectiveness of interventions to increase blood donation among ethnic/racial minority populations in developed countries. We searched MEDLINE, EMBASE, CINAHL, and ProQuest on 20 March 2017 with no date restrictions and supplemented this with searches on Google Scholar, blood collection agency websites, reference lists of included studies, and a forward search of citations of included studies. We included intervention studies designed to increase recruitment and/or retention of adult, ethnic/racial minority blood donors in developed countries. The review identified eight studies reported in nine publications. Six were conducted in the USA with African Americans. Four studies reported on multifaceted, community-based interventions; three reported on one-off information and educational video interventions, presented face-to-face, or delivered via post or e-mail. The level of evidence for efficacy was low, and the majority of studies were assessed as having some risk of bias related to one or more methodological issues. All eight studies reported positive outcomes in blood donation and/or intention to donate. Seven trials found that the intervention increased presentation for donation, and three found an increase in the percentage of new donors from the ethnic minority targeted. The review findings demonstrate that it is possible to design and implement effective interventions to motivate individuals from ethnic/racial minority groups to donate blood. One-off interventions may be as effective as multifaceted, community-based interventions. There was insufficient evidence to recommend particular interventions, and future research should empirically assess alternative interventions using robust study designs.

Red cell transfusion in paediatric patients with thalassaemia and sickle cell disease: Current status, challenges and perspectives

Notwithstanding the high safety level of the currently available blood for transfusion and the decreasing frequency of transfusion-related complications, administration of labile blood products to paediatric patients still poses unique challenges and considerations. The incidence of thalassaemia and sickle cell disease in the paediatric population may be high enough under specific racial and geographical contexts. Red cell transfusion is the cornerstone of β-thalassaemia treatment and one of the most effective ways to prevent or correct specific acute and chronic complications of sickle cell disease. However, this life-saving strategy comes with its own complications, such as additional iron overload, alloimmunization and haemolytic reactions, among others. In paediatrics, the dependency of the transfusion outcome upon disease and other recipient characteristics is more prominent compared with the adults, owing to differences in developmental maturity and physiology that render them more susceptible to common risks, exacerbate the host response to transfused cells, and modify the type or the clinical severity of the transfusion-related morbidity. The adverse branch of red cell transfusion is likely the overall effect of several factors acting synergistically to shape the clinical phenotype of this therapy, including inherent donor/blood unit variables, like antigenicity, red cell deformability and extracellular vesicles, as well as recipient variables, such as history of alloimmunization and inflammation level at time of transfusion. This review focuses on paediatric patients with β-thalassaemia and sickle cell disease as a recipient group with distinct transfusion-related characteristics, and introduces new concepts for consideration, not adequately studied and elucidated so far.

Glucose-6-phosphate-dehydrogenase deficient red blood cell units are associated with decreased posttransfusion red blood cell survival in children with sickle cell disease

Chronic transfusion therapy (CTT) for sickle cell disease (SCD) reduces disease morbidity by suppressing the amount of circulating hemoglobin S (HbS)-containing red blood cells (RBC). The effectiveness of CTT depends on the rate of RBC clearance. Glucose-6-phosphate dehydrogenase (G6PD) deficient donor RBC may exhibit increased hemolysis, but it is unknown if transfusion of these units results in less effective transfusion outcomes in SCD. Children with SCD on CTT were followed prospectively for multiple transfusions. G6PD activity of transfused units was measured prior to expiration date. HbA clearance (ΔHbA) was calculated as the difference of estimated posttransfusion HbA to the pretransfusion HbA of the subsequent transfusion episode. Sixty-two patients received 388 transfusions. Of 755 RBC units, 687 (91%) had normal G6PD (>60% activity), 38 (5%) had moderately low G6PD (10-60% activity), and 30 (4%) had severely low G6PD (<10% activity). Of 358 evaluable transfusions, 54 (15%) included ≥1 G6PD deficient units, and 22 (6%) had ≥1 severely deficient units. The proportion of the transfusion episode consisting of G6PD deficient units was associated with increased ΔHbA for all G6PD deficient units (P = .05) and for severely G6PD deficient units (P = .0070). In multivariate mixed effects modeling, ΔHbA was positively associated with severely G6PD deficient units (P = .0074) and RBC alloimmunization (P = .03) and negatively associated with recipient splenectomy (P = .015). Higher ΔHbA was associated with higher HbS and reticulocyte counts at the subsequent transfusion episode. In conclusion, G6PD deficient RBC transfusions may have shorter in vivo survival and adversely affect the suppression of sickle erythropoiesis.