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Background: Post-transfusion survival of donor red blood cells (RBCs) is important for effective chronic transfusion therapy in conditions including sickle cell disease (SCD). Biotin labeling RBCs allows direct in vivo measurement of multiple donor RBC units simultaneously post-transfusion., Study Design and Methods: In an observational trial of patients with SCD receiving monthly chronic transfusion therapy, aliquots of RBCs from one transfusion episode were biotin-labeled and infused along with the unlabeled RBC units. Serial blood samples were obtained to measure RBC survival. Donor units were tested for RBC indices, hemoglobin fractionation, and glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. For microcytic donor RBCs (MCV < 70 fL), HBA1 and HBA2 genetic testing was performed on whole blood., Results: We present one recipient, a pediatric patient with SCD and splenectomy who received two RBC units with aliquots from each unit labeled at distinct biotin densities (2 and 18 μg/mL biotin). One donor unit was identified to have microcytosis (MCV 68.5 fL after biotinylation); whole blood sample obtained at a subsequent donation showed 2-gene deletion alpha-thalassemia trait (ɑ- 3.7kb /ɑ- 3.7kb ) and normal serum ferritin. G6PD activity was >60% of normal mean for both. The RBCs with alpha-thalassemia RBC had accelerated clearance and increased surface phosphatidylserine post-transfusion, as compared with the normocytic RBC (half life 65 vs. 86 days, respectively)., Discussion: Post-transfusion RBC survival may be lower for units from donors with alpha-thalassemia trait, although the impact of thalassemia trait donors on transfusion efficacy requires further study., (© 2024 AABB.)

Background: Red blood cell (RBC) antibodies are common in multiply transfused patients with sickle cell disease (SCD). Unlike RBC alloantibodies, the potential of autoantibodies to cause post-transfusion hemolysis may be uncertain. Biotin-labeling provides a direct measurement of red cell survival (RCS) over time, thus can be used to assess the clinical significance of RBC antibodies. Antibodies to biotinylated RBC (B-RBC) occasionally are detected after exposure, which may impact B-RBC survival in subsequent RCS studies., Study Design and Methods: Pediatric patients with SCD receiving monthly chronic transfusions underwent RCS studies, receiving aliquots of allogeneic RBC labeled at distinct densities of biotin (2-18 μg/mL). B-RBC survival was followed for 4 months post-transfusion, and B-RBC antibody screening for 6 months. Patients with warm autoantibodies (WAA) or B-RBC antibodies are reported here., Results: RBC antibodies were detected during RCS in four patients: one with WAA, one with WAA followed by B-RBC-specific antibodies, and two with transient B-RBC antibodies within the first 5 weeks of exposure. B-RBC half-lives (T 50 ) ranged 37.6-61.7 days (mean 47.8 days). There was no evidence of increased hemolysis or accelerated B-RBC clearance in the presence of WAA or B-RBC antibodies., Discussion: Biotinylation of allogenic RBC can be used to assess the possible effects of RBC antibodies on transfusion survival in individual cases, particularly when it is uncertain if the detected antibodies may result in hemolysis. In the cases presented here, neither WAA nor B-RBC antibodies were associated with significant shortening of B-RBC survival in individuals with SCD., (© 2024 AABB.)

Background: Children are at increased risk from transfusion-related medical errors. Clinical decision support (CDS) can enhance pediatric providers' decision-making regarding transfusion practices including indications, volume, rate, and special processing instructions. Our objective was to use CDS in a pediatric health system to reduce:blood product-related safety events from ordering errors;special processing ordering errors for patients with T-cell dysfunction, sickle cell disease (SCD), or thalassemia;transfusions administered faster than 5 mL/kg/h., Materials and Methods: In this single-center before and after quality improvement study, we evaluated how user-centered design of pediatric blood product orders influenced pediatric transfusion practices and outcomes. Safety events were identified through active and passive surveillance. Other clinically relevant outcomes were identified through electronic health record queries., Results: Blood product-related safety events from ordering errors did not change significantly from the baseline period (6 events, 0.4 per month, from 1/1/2018-3/27/2019) to the intervention period (1 event, 0.1 per month, from 3/28/2019-12/31/2019; rate ratio: 0.27 [0.01-2.25]). Packed red blood cell (PRBC) and platelet orders for patients with T-cell dysfunction that did not specify irradiation decreased significantly from 488/12,359 (3.9%) to 204/6,711 (3.0%, risk ratio: 0.77 [0.66-0.90]). PRBC orders for patients with SCD or thalassemia that did not specify phenotypically similar units fell from 386/2,876 (13.4%) to 57/1,755 (3.2%, risk ratio: 0.24 [0.18-0.32]). Transfusions administered faster than 5 mL/kg/h decreased from 4,112/14,641 (28.1%) to 2,125/9,263 (22.9%, risk ratio: 0.82 [0.78-0.85])., Discussion: User-centered design of CDS for pediatric blood product orders significantly reduced special processing ordering errors and inappropriate transfusion rates. Larger studies are needed to evaluate the impact on safety events.

Background: Resistance to malaria infection may be conferred by erythrocyte genetic variations including glucose-6-phosphate dehydrogenase (G6PD) deficiency and lack of Duffy antigens. In red blood cell (RBC) transfusion, G6PD deficiency may shorten transfusion survival. Because Duffy-null units are commonly transfused in sickle cell disease (SCD) due to antigen matching protocols, we examined whether Duffy-null donor RBC units have a higher prevalence of G6PD deficiency., Materials and Methods: Pediatric patients with SCD on chronic transfusion therapy were followed prospectively for multiple transfusions. RBC unit segments were collected to measure G6PD activity and RBC genotyping. The decline in donor hemoglobin (ΔHbA) following transfusion was assessed from immediate posttransfusion estimates and HbA measurements approximately 1 month later., Results: Of 564 evaluable RBC units, 59 (10.5%) were G6PD deficient (23 severe, 36 moderate deficiency); 202 (37.6%) units were Duffy-null. G6PD deficiency occurred in 40 (19.8%) Duffy-null units versus 15 (4.5%) Duffy-positive units (p < .0001). In univariate analysis, the fraction of Duffy-null RBC units per transfusion was associated with greater decline in HbA (p = .038); however, in multivariate analysis, severe G6PD deficiency (p = .0238) but not Duffy-null RBC (p = .0139) were associated with ΔHbA., Conclusion: Selection of Duffy-null RBC units may result in shorter in vivo survival of transfused RBCs due to a higher likelihood of transfusing units from G6PD deficient donors., (© 2022 AABB.)

Background: Chronic automated red cell exchange (RCE) is increasingly employed for sickle cell disease (SCD). There is a paucity of data on the incidence of RCE adverse events (AEs) and potential patient and procedural risk factors for AEs., Methods: A retrospective review of pediatric SCD patients receiving chronic RCE over 3 years was performed to determine the frequency of AEs and identify procedural and patient AE risk factors. AE incidence, AE rate, incidence rate ratios (IRRs), and relative risks (RRs) were calculated based on various procedural and patient characteristics by univariable (UV) and multivariable (MV) analyses., Results: In 38 patients receiving 760 procedures, there were 150 (19.7%) AEs, 36 (4.7%) were symptomatic AEs. AE rates were 20.2 [95% CI 17.2, 23.6] and 4.8 [95% CI 3.49, 6.70] per 100 person months for AEs and symptomatic AEs, respectively. AE incidences were: hypocalcemia (117; 15.4%), dizziness (22; 3.0%), hypotension (15; 2.0%), and nausea (14; 1.8%). Patients with baseline Hct ≥30% experienced more total AEs and symptomatic AEs. Patients with pre-procedure systolic BP <50th percentile, severe CNS vasculopathy, and non-SCA genotype (HbSC or Sβ + thalassemia) exhibited more total AEs. IHD depletion was not associated with an increased incidence of AEs or symptomatic AEs., Conclusion: SCD patients with Hct ≥30%, systolic BP <50th percentile, severe CNS vasculopathy, and possibly non-SCA genotype may be at higher risk for RCE-related AEs. The effect of IHD on AE risk is likely minimal. Individualized AE risk assessment should be performed in all SCD patients undergoing chronic automated RCE., (© 2022 AABB.)

Background: Patients with sickle cell disease (SCD) may require chronic transfusion therapy (CTT) for prevention of stroke or other complications. Limited health literacy (HL) is common and is associated with poor health-related knowledge and outcomes in chronic disease. We sought to assess HL and transfusion knowledge in patients with SCD on CTT and their caregivers., Methods: A cross-sectional study of patients was conducted in outpatient hematology clinics. Forty-five pairs of adolescent patients and caregivers and 20 caregivers of pre-adolescent patients completed the Newest Vital Sign HL assessment and answered questions assessing SCD and transfusion knowledge. Community-level median income and unemployment rates were estimated from Census data. We computed the correlation of HL with knowledge and compared each to Census variables, payor status, educational attainment, and stroke., Results: HL was inadequate in 22 (34%) caregivers and 31 (69%) adolescents. Adequate caregiver HL was associated with higher educational attainment but not community-level socioeconomics or payor status. Mean knowledge score was lower in adolescents than in caregivers and correlated with age in adolescents (r = 0.42, P = .004). HL correlated with knowledge (r = 0.46, P < .0001). There were no significant correlations of HL or knowledge between adolescents and their caregivers. Neither HL nor knowledge was associated with prior stroke. The greatest knowledge was demonstrated for iron overload and SCD genotype, whereas knowledge gaps existed in alloimmunization, indication for CTT, and SCD curative therapy., Conclusions: Enhanced educational resources in transfusion therapy, alloimmunization, and curative therapy are needed for patients with SCD and caregivers of all HL levels., (© 2019 Wiley Periodicals, Inc.)

Objectives: To assess current knowledge of National Heart, Lung and Blood Institutes (NHLBI) and Thalassemia International Federation (TIF) recommendations, blood banking practices and perceived challenges among transfusion services in the management of patients with haemoglobinopathies., Background: Previous reports have demonstrated variations in transfusion practices for sickle cell disease (SCD) and thalassemia patients. Recently, NHLBI/TIF have provided transfusion recommendations for patients with haemoglobinopathies., Methods: A cross-sectional survey was conducted of transfusion services from the state of Georgia previously identified as having SCD/thalassemia populations. The survey assessed transfusion service practices in pre-transfusion testing and blood product selection; awareness/implementation of NHLBI/TIF transfusion-based recommendations and perceived challenges in transfusing haemoglobinopathy patients., Results: Responses were received from 35 of 49 (71%) institutions. Only institutions indicating transfusing SCD or thalassemia patients (32) were included in analysis. Seventy-one percent of non-sickle cell treatment centres (SCTCs) and 20% of non-thalassemia treatment centres follow NHLBI and TIF recommendations to perform a red blood cell phenotype beyond ABO/Rh(D) and provide Rh and Kell prophylactically matched units for SCD and thalassemia patients, respectively. Forty percent of institutions (33% of non-SCTCs) employ RBC genotyping to evaluate the red cell phenotype for SCD patients. Over 77% of institutions do not utilise a reliable method to identify SCD patients prior to transfusion, such as a required question/answer field on type/screen or crossmatch orders., Conclusion: Many healthcare systems' transfusion practices for haemoglobinopathy patients are discordant with NHLBI/TIF recommendations. Efforts are needed to increase awareness and implementation of current recommendations among all transfusion services seeing these patients., (© 2019 The Authors. Transfusion Medicine published by John Wiley & Sons Ltd on behalf of British Blood Transfusion Society.)

Red blood cell (RBC) transfusion support represents a critical component of sickle cell disease (SCD) management. However, as with any therapeutic intervention, RBC transfusion is not without risk. Repeat exposure to allogeneic RBCs can result in the development of RBC alloantibodies that can make it difficult to find compatible RBCs for future transfusions and can directly increase the risk of developing acute or delayed hemolytic transfusion reactions, which can be further complicated by hyperhemolysis. Several prophylactic and treatment strategies have been employed in an effort to reduce or prevent hemolytic transfusion reactions. However, conflicting data exist regarding the efficacy of many of these approaches. We will explore the challenges associated with predicting, preventing and treating different types of hemolytic transfusion reactions in patients with SCD in addition to describing future strategies that may aid in the management of the complex transfusion requirements of SCD patients., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Objectives: To present the recommendations and supporting evidence for RBC transfusions in critically ill children with hematologic and oncologic disease from the Pediatric Critical Care Transfusion and Anemia Expertise Initiative., Design: Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children., Methods: The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations and research priorities for RBC transfusions in critically ill children. The hematologic/oncologic subgroup included seven experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method., Results: The hematologic/oncologic subgroup developed 14 recommendations (seven clinical, seven research); all achieved greater than 80% agreement. In patients with sickle cell disease, Transfusion and Anemia Expertise Initiative recommends: 1) RBC transfusion to achieve a target hemoglobin concentration of 10 g/dL rather than hemoglobin of less than 30% prior to surgical procedures requiring general anesthesia and 2) exchange transfusion over simple (nonexchange) transfusion if the child's condition is deteriorating (based on clinical judgment), otherwise a simple, nonexchange RBC transfusion is recommended. There is insufficient evidence to make recommendations on transfusion thresholds for patients with sickle cell disease prior to minor procedures, with acute stroke or with pulmonary hypertension. For patients with oncologic disease or undergoing hematopoietic stem cell transplant, a hemoglobin concentration of 7-8 g/dL is recommended. Due to lack of evidence, research is needed to clarify the appropriate transfusion thresholds in these patients., Conclusions: Transfusion and Anemia Expertise Initiative developed specific pediatric recommendations regarding RBC transfusion management in critically ill children with sickle cell disease, oncologic disease, and hematopoietic stem cell transplant and recommendations to help guide future research priorities.

Background: Fever accompanying vaso-occlusive crisis is a common presentation in patients with sickle cell disease (SCD) and carries a broad differential diagnosis. Here, we report a case of transfusion-transmitted malaria in a patient with SCD presenting with acute vaso-occlusive crisis and rapidly decompensating to multisystem organ failure (MSOF)., Case Report: An 18-year-old African American male with SCD was admitted after multiple days of fever and severe generalized body pain. He received monthly blood transfusions as stroke prophylaxis. A source of infection was not readily identified, but treatment was initiated with continuous intravenous fluids and empiric antibiotics. The patient developed acute renal failure, acute hypoxic respiratory failure, and shock. He underwent red blood cell (RBC) exchange transfusion followed by therapeutic plasma exchange and continuous veno-venous hemodialysis. A manual peripheral blood smear revealed intraerythrocytic inclusions suggestive of Plasmodium, and molecular studies confirmed Plasmodium falciparum infection. Intravenous artesunate was given daily for 1 week. A look-back investigation involving two hospitals, multiple blood suppliers, and state and federal public health departments identified the source of malaria as a unit of RBCs transfused 2 weeks prior to admission., Conclusions: Clinical suspicion for transfusion-related adverse events, including hemolytic transfusion reactions and transfusion-transmitted infections, should be high in typically and atypically immunocompromised patient populations (like SCD), especially those on chronic transfusion protocols. Manual blood smear review aids in the evaluation of patients with SCD presenting with severe vaso-occlusive crisis and MSOF and can alert clinicians to the need for initiating aggressive therapy like RBC exchange and artesunate therapy., (© 2018 AABB.)

Background: Chronic transfusion therapy for sickle cell anemia reduces disease complications by diluting sickle-erythrocytes with hemoglobin A (HbA)-containing erythrocytes and suppressing erythropoiesis. Minor antigen mismatches may result in alloimmunization, but it is unknown if antigen mismatches or recipient characteristics influence HbA clearance posttransfusion., Study Design and Methods: Children with sickle cell anemia on chronic transfusion therapy were followed prospectively for 12 months. All patients received units serologically matched for C/c, E/e, and K; patients with prior red blood cell (RBC) antibodies had additional matching for Fy a , Jk b , and any previous alloantibodies. Patients' RBC antigen genotypes, determined by multiplexed molecular assays (PreciseType Human Erythrocyte Antigen, and RHCE and RHD BeadChip, Immucor) were compared to genotypes of transfused RBC units to assess for antigen mismatches. Decline in hbA (ΔHbA) from posttransfusion to the next transfusion was calculated for each transfusion episode., Results: Sixty patients received 789 transfusions, 740 with ΔHbA estimations, and 630 with donor Human Erythrocyte Antigen genotyping. In univariate mixed-model analysis, ΔHbA was higher in patients with past RBC antibodies or splenomegaly and lower in patients with splenectomy. RBC antigen mismatches were not associated with ΔHbA. In multivariate linear mixed-effects modeling, ΔHbA was associated with RBC antibodies (2.70 vs. 2.45 g/dL/28 d, p = 0.0028), splenomegaly (2.87 vs. 2.28 g/dL/28 d, p = 0.019), and negatively associated with splenectomy (2.46 vs. 2.70 g/dL/28 d, p = 0.011)., Conclusions: HbA decline was increased among patients with sickle cell anemia with prior immunologic response to RBC antigens and decreased among those with prior splenectomy, demonstrating that recipient immunologic characteristics influenced the clearance of transfused RBCs., (© 2018 AABB.)

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., (© 2018 Wiley Periodicals, Inc.)

Background: Red blood cell (RBC) alloimmunization occurs at a high frequency in sickle cell anemia (SCA) despite serologic matching for Rh (C/c, E/e) and K antigens. RBC minor antigen genotyping allows for prediction of antigens and RH variants that may lead to alloimmunization., Study Design and Methods: RBC antigen genotyping was performed on chronically transfused pediatric SCA patients, using PreciseType human erythrocyte antigen (HEA), RHCE, and RHD BeadChip arrays. All patients received C/c, E/e, and K serologically matched units (Category 1); patients with prior RBC antibodies were also matched for Fy a , Jk b , and any antibodies (Category 2). The RBC genotypes of all leukoreduced (LR) units transfused over a 12-month period were determined by the prototype HEA-LR BeadChip assay., Results: There were 2320 RBC units transfused to 90 patients in 1135 transfusion episodes. Thirty-five (38.9%) patients had homozygous or compound heterozygous RH variants. Seven new alloantibodies were detected, with alloantibody incidence of 0.706 in 100 units for Category 2 transfusions and 0.068 in 100 units for Category 1 (p = 0.02). Three patients on Category 2 transfusions formed new anti-Js a and had a higher rate of exposure to Js a than those who did not form anti-Js a (20.4 vs. 8.33 exposures/100 units, p = 0.02). The most frequent mismatches were S (43.9%), Do a (43.9%), Fy a (29.2%), M (28.4%), and Jk b (28.1%)., Conclusions: Alloimmunization incidence was higher in those with prior RBC antibodies, suggesting that past immunologic responders are at higher risk for future alloimmunization and therefore may benefit from more extensive antigen matching beyond C/c, E/e, K, Fy a , and Jk b ., (© 2017 AABB.)

Background: Although red blood cell (RBC) transfusion represents an integral component of sickle cell disease (SCD) care, transfusion support for some patients can result in alloimmunization to RBC antigens. Alloimmunized patients with SCD appear to experience worse survival compared to nonalloimmunized patients. While this difference in mortality may in part be due to underlying immunologic differences related to disease severity, it may also reflect direct clinical consequences of RBC alloimmunization. Alloimmunized patients have an increased risk of serious hemolytic transfusion reactions (HTRs) and may not receive adequate RBC transfusion support due to lack of compatible RBC units., Case Report: This study reports on five RBC alloimmunized patients with SCD who died, to illustrate the concept that RBC alloimmunization itself contributes to premature death., Results: The clinical course for each of the reported patients provides insight into the direct and indirect consequences of RBC alloimmunization, where patients experienced delayed HTRs or did not receive needed RBC transfusions., Conclusion: Future work examining the clinical impact of RBC alloimmunization should not only consider HTRs but should also address the potential consequences associated with difficulties in obtaining compatible blood., (© 2015 AABB.)

Alloimmunization against red blood cell (RBC) antigens is a cause of morbidity and mortality in transfused patients with sickle cell disease (SCD). To investigate distinguishing characteristics of patients who develop RBC alloantibodies after transfusion (responders) versus those who do not (non-responders), a cross-sectional study of 90 children with SCD on chronic RBC transfusion therapy at a single institution was conducted in which 18 immune parameters (including T and B cell subsets) were tested via flow cytometry, and medical records were reviewed. RBC alloimmunization was present in 26/90 (29%) patients, with anti-E, K, and C among the most commonly detected alloantibodies despite prophylactic matching for these antigens at the study institution. In addition, RBC autoantibodies had been detected in 18/26 (69%) of alloimmunized versus 7/64 (11%) of non-alloimmunized patients (P < 0.0001). Alloimmunized patients were significantly older (median 13.0 years vs. 10.7 years, P = 0.010) and had more RBC unit exposures (median 148 U vs. 82 U, P = 0.020) than non-alloimmunized patients. Sex, age at initiation of chronic transfusion, splenectomy, stroke, and transfusion outside of the study institution were not significantly associated with RBC alloimmunization. Alloimmunized patients had a significantly increased percentage of CD4+ T memory cells compared to non-alloimmunized patients (57% vs. 49%, P = 0.0047), with no other significant differences in immune cell subsets or laboratory values detected between these groups. Additional research of RBC alloimmunization is needed to optimize transfusion therapy and to develop strategies to prevent alloimmunization., (© 2015 Wiley Periodicals, Inc.)

The Atlanta Sickle Cell Consortium represents more than 2600 pediatric and adult patients with sickle cell disease (SCD) in the metropolitan Atlanta, Georgia, area receiving care at four major locations, each providing comprehensive care 24 hours a day, 7 days a week. Both transfusion services that support these sites use two levels of prospective phenotype matching to decrease the rates of alloimmunization. Although exact rates are unknown and are currently under investigation, alloimmunization occurs infrequently with the exception of chronically transfused SCD patients, who represent the minority of active SCD patients. With increasing availability, red blood cell genotyping will be used in the near future both for determination of predicted patient phenotypes and for provision of genotypically matched donor units.

Background: Alloimmunization to minor red blood cell (RBC) antigens occurs commonly in sickle cell disease (SCD). Patients with alloimmunization demonstrate increased risk for new alloantibody formation with subsequent transfusion. Alloimmunization to human leukocyte antigens (HLA) can occur with RBC transfusion and may result in graft rejection during stem cell or organ transplantation. The prevalence and risk factors for HLA alloimmunization in multiply transfused pediatric SCD patients are unknown., Procedure: A cross-sectional study of HLA alloimmunization in SCD patients aged 3-21 years with a history of >or=3 RBC transfusions was performed to test the hypothesis that HLA alloimmunization is associated with RBC alloimmunization. Antibodies to class I and class II HLA were measured by Flow Panel Reactive Antibody (FlowPRA)., Results: Seventy-three SCD patients (30 with RBC antibodies) were tested. HLA antibodies were detected in 25/73 (34%) patients; class I HLA antibodies occurred in 24/73 (33%) and class II HLA antibodies occurred in 3 (4%). Among patients with RBC antibodies, 16/30 (53%) had HLA antibodies, while 9/43 (21%) patients without RBC antibodies had HLA antibodies (OR 4.32 [1.6-12.1]). In a multivariate analysis, antibodies to RBC antigens were an independent predictor of HLA alloimmunization (P = 0.041). The association of RBC and HLA immunization was strongest among patients with no history of chronic transfusion therapy., Conclusions: This analysis is the first description of HLA alloimmunization in pediatric SCD patients who receive primarily leukoreduced RBC transfusions and demonstrates that HLA alloimmunization tendency is associated with antibodies to RBC antigens.

Background: Sickle cell disease (SCD) patients have unique transfusion considerations during bone marrow transplantation (BMT), including prophylaxis against stroke and alloimmunization. Characterization of transfusion requirements is important for blood bank and clinician patient management., Study Design and Methods: A retrospective analysis of red blood cell (RBC) and platelet (PLT) transfusion of SCD patients during myeloablative matched sibling donor (MSD) BMT at one institution from 1993 to 2007 was performed. Patient characteristics (RBC blood group antibodies, ABO-incompatible donor, BMT-related morbidity) and transfusion practices (RBC phenotype matching, transfusion threshold, and blood age) were assessed for effect on total RBC transfusion volumes., Results: Twenty-seven patients received MSD BMT with 96% survival and 0% rejection. Six alloimmunized patients received RBCs with extended phenotype matching (C, c, E, e, K, Fy(a), Jk(b)), 14 nonalloimmunized received limited matching (C, c, E, e, K), and 7 did not have phenotype matching. Among 26 survivors, a median seven RBC transfusions (range, 3-15) and 13.5 PLT transfusions (range, 4-48) per patient were administered, equivalent to 64 mL/kg RBCs (range, 22-122 mL/kg) and 106 mL/kg PLTs (range, 26-343 mL/kg). BMT-related morbidity predicted increased RBC transfusions (p = 0.006). Venoocclusive disease was associated with greater RBC (p = 0.016) and PLT transfusion volumes (p = 0.016). Greater phenotype matching was associated with decreased RBC transfusions (p = 0.0247)., Conclusions: SCD patients have high transfusion support during MSD BMT. Communication of BMT complications to the blood bank is essential for transfusion inventory management. Phenotype matching decreased RBC transfusions in this cohort and warrants further investigation in SCD transfusion therapy.

Anti-CD36 antibodies are known to cause a platelet refractory state. We describe a previously unreported case of a 16-year-old female sickle cell disease patient with anti-CD36 antibodies, detected on routine screen prior to hematopoietic stem cell transplantation (HSCT). CD36 platelet antigen typing was negative for both the patient and her HLA-identical donor sibling. Patient plasma was compatible with 48 of 49 apheresis platelets, which were untested and presumably positive for the CD36 antigen. The patient responded adequately to transfusion of crossmatch compatible platelets and successfully underwent HSCT. The presence of anti-CD36 antibodies does not exclude potential candidates from HSCT., ((c) 2007 Wiley-Liss, Inc.)

The clinical outcomes of sickle cell disease (SCD) have vastly improved over the years in great part as a result of advanced medical technologies, improved patient education, and multidisciplinary care. A key component in the successful management of patients with SCD is red blood cell transfusion therapy used in the treatment and prevention of sickle cell complications. However, although the successful application of transfusion therapy has significantly improved the morbidity and mortality of patients with SCD, the literature that addresses the appropriate selection and use of blood products continues to evolve with no clear universal standard of care. Our objectives were to provide an in-depth review of the current literature on transfusion therapy in SCD and to provide a set of guidelines for the transfusion management of patients with SCD.