Red blood cell alloimmunization among sickle cell Kuwaiti Arab patients who received red blood cell transfusion

BACKGROUND: Sickle cell disease (SCD) is common in the Arabian Gulf region. Most cases require a red blood cell (RBC) transfusion, increasing the potential for RBC alloantibody development. The incidence of RBC alloimmunization among Kuwaiti Arab SCD patients is not yet known. This study retrospectively assessed the effect of using two different matching protocols on the incidence of alloimmunization among multiply transfused Kuwaiti Arab SCD patients.
STUDY DESIGN AND METHODS: A total of 233 Kuwaiti Arab SCD patients were divided into two groups: Group 1 (n = 110) received RBC transfusion through standard ABO- and D-matched nonleukoreduced blood; Group 2 (n = 123) received RBCs matched for ABO, Rh, and K1 poststorage-leukoreduced blood. Multivariate analysis was performed on the factors associated with RBC alloimmunization and antibody specificity.
RESULTS: Sixty-five percent of patients in Group 1 developed clinically significant RBC alloantibody with an increased prevalence in females; in patients in Group 2, 23.6% developed RBC alloantibodies (p = 0.01). In Group 1, 72 patients (65.5%) had alloantibodies directed against Rh and Kell systems (p = 0.01). Multivariate analysis further confirmed the results, showing that blood transfusion type and sex have significant effects on the rate of alloimmunizations.
CONCLUSION: This study confirms the importance of selecting RBCs matched for Rh and Kell to reduce the risk of alloimmunizations among Kuwaiti Arab SCD patients.     

Red blood cell alloimmunization in transfused patients with myelodysplastic syndrome or chronic myelomonocytic leukemia

BACKGROUND: Red blood cell (RBC) alloimmunization is a major problem in chronically transfused patients because of the risk of hemolytic reactions and limited availability of compatible blood. This study was aimed at determining the characteristics of RBC alloimmunization in transfusion‐dependent patients with myelodysplastic syndrome or chronic myelomonocytic leukemia (MDS/CMML). STUDY DESIGN AND METHODS: The transfusion and clinical records of all patients with MDS/CMML seen at our hospital from 1990 to 2009 were reviewed. The cumulative incidence of RBC alloimmunization was calculated by taking death as a competing risk. Incidence rates were compared by Poisson multivariate regression. RESULTS: A total of 272 patients were included. Median age was 74 years; 55% were men and had received a median of 33 (range, 4‐421) RBC units. Forty‐two (15%) patients formed 81 alloantibodies and seven autoantibodies. Three additional patients developed autoantibodies without alloantibodies. The incidence rate of RBC alloimmunization was 1 per 10.5 person‐years and was independent of sex, age, and MDS diagnostic category. The cumulative incidence of alloimmunization increased with the number of RBC transfusions, reaching a plateau at 19.5% after 130 RBC units. The most common antibody specificities were Kell (26 cases), E (19), c (5), and Jk^a (5). In 26 (62%) of the 42 alloimmunized patients, only the Rh system and Kell were involved. CONCLUSION: RBC alloimmunization occurs in 15% of MDS/CMML patients on chronic transfusion support and mostly involves the Rh system and Kell. Transfusing these patients with extended antigen‐matched blood, including Kell and CcEe antigens, would presumably reduce the RBC immunization rate.     

An acute hemolytic transfusion reaction due to anti-IH in a patient with sickle cell disease

BACKGROUND: A hemolytic transfusion reaction (HTR) due to anti-IH is reported in a patient with sickle cell disease (SCD). CASE REPORT: An 18-year-old woman with SCD and a complete phenotype on file had been identified as group B-positive with negative antibody-screening tests and had received 1 unit of packed RBCs. Ten days later, she was readmitted in painful crisis with a Hb of 4.2 g per dL. Antibody-screening tests and panel cells were positive at all test phases with a negative autocontrol, which suggested alloantibodies. Phenotypically matched group O RBCs were issued emergently. After the transfusion of 100 mL, the patient had an HTR with chills, fever, and tachycardia and laboratory findings of hemoglobinemia, hemoglobinuria, and negative DATs. A high-titer, IgM anti-IH with a high thermal amplitude (reactive with group O, but not group B RBCs at 37 degrees C) was identified. Autologous RBCs appeared to have normal I antigen expression, but less H antigen than pooled group B RBCs. She was given group B RBCs, uneventfully, by use of a blood warmer. CONCLUSIONS: This is a rare case of anti-IH as the cause of a HTR, as a serologic problem that may be seen in SCD, and as an autoantibody that may mimic an alloantibody. Ironically, this HTR resulted from the effort to provide phenotypically matched RBCs, which necessitated the selection of group O RBCs.     

Red blood cell alloimmunization in transfusion-dependent Egyptian patients with thalassemia in a limited donor exposure program

BACKGROUND: Thalassemia is considered the most common hemoglobinopathy in Egypt and is one of its major health problems. Lifelong red blood cell (RBC) transfusion remains the main treatment for severe forms; however, RBC alloimmunization results as a complication of regular transfusions due to repeated exposure to foreign antigens. The objective was to compare the frequency of alloantibodies in a group of patients in a limited donor exposure program (LDEP) with those receiving RBCs from multiple donors in Egyptian transfusion‐dependent patients with thalassemia. STUDY DESIGN AND METHODS: A total of 235 regularly transfused patients with thalassemia were studied, 36 of which were on LDEP. All patients were investigated for the presence of RBC autoantibodies and alloantibodies, followed by antibody identification for positive patients. RESULTS: Forty‐six (19.5%) patients developed RBC alloantibodies. The most common clinically significant alloantibodies were directed against antigens in the Kell and Rh systems. Development of alloantibodies was associated with older age, higher transfusion frequency, and splenectomy. A trend toward lower alloimmunization was elicited in the LDEP group, where 8.3% (3/36) patients were alloimmunized compared to 21.6% (43/199) in the non‐LDEP one (p = 0.057). CONCLUSIONS: Examination of donor RBCs for presence of Kell and Rh(E) antigens before transfusion can help decrease RBC alloimmunization. Further larger studies are required to assess the frequency of alloantibody production in patients on LDEP.     

Prestorage universal WBC reduction of RBC units does not affect the incidence of transfusion reactions

BACKGROUND: Febrile nonhemolytic transfusion reaction (FNHTR) has been identified as a pivotal reason for prestorage universal WBC reduction. A regional blood center implemented universal prestorage WBC reduction for RBCs on January 1, 2000. Whether prestorage universal WBC reduction of RBC units will affect FNHTR is not known. STUDY DESIGN AND METHODS: All reports of RBC transfusion reactions at Barnes-Jewish Hospital submitted for evaluation to the blood bank, before and after the implementation of WBC reduction of RBCs, were retrospectively evaluated. RESULTS: For the 36,303 allogeneic RBC transfusions administered in 1999, 85 reactions (0.23%) were reported. These reactions were classified as FNHTR in 43 cases, allergic in 13, delayed hemolytic in 19, and miscellaneous in 10. For the 31,543 non-WBC-reduced RBC transfusions performed in 1999, 78 reactions (0.25%) were reported. These reactions were classified as FNHTR in 39 cases, allergic in 13, delayed hemolytic in 19, and miscellaneous in 7. In the first half of 2000, 32 reactions (0.20%) were reported for 16,093 prestorage WBC-reduced RBC transfusions (p = 0.41). There were 13 FNHTRs and 10 allergic, 7 delayed hemolytic, and 2 miscellaneous reactions. The use of prestorage WBC-reduced RBCs did not significantly affect the rate of reactions classified as allergic (0.04% in 1999; 0.06% in 2000; p = 0.43) or as FNHTR (0.12% in 1999; 0.08% in 2000; p = 0.33). For all patients, universal WBC reduction in 2000 did not reduce the rate of FNHTR from the rate seen with selective bedside WBC reduction, the practice used in 1999 (0.12% in 1999; 0.08% in 2000; p = 0.36). CONCLUSION: No significant difference was found in the incidence of transfusion reactions in patients receiving prestorage WBC-reduced RBCs and non-WBC-reduced RBCs. In addition, no difference was found in transfusion reaction rates when periods of prestorage universal WBC reduction were compared to those of selective WBC reduction.     

Severe delayed hemolytic transfusion reaction secondary to anti-Ata

BACKGROUND: Anti-At(a) is a rare red cell (RBC) alloantibody found in the black population. It has been described as causing one case of mild hemolytic disease of the newborn, but its ability to cause hemolytic transfusion reactions is uncertain. CASE REPORT: The patient was a 60-year-old black female with a history of three uneventful pregnancies but no transfusions. On admission, her direct and indirect antiglobulin tests were negative, total bilirubin was 0.5 mg per dL, and lactate dehydrogenase was 224 IU per L. She received nine units of compatible RBCs in the perioperative period of a hemicolectomy. Her hemoglobin rose appropriately and stabilized at 12.6 g per dL by the 6th postoperative day. By Day 10 after surgery her hemoglobin had dropped to 6.8 g per dL, and her total bilirubin and lactate dehydrogenase had risen to 1.4 mg per dL and 783 IU per L, respectively. The direct and indirect antiglobulin tests were now newly positive with strengths of 3+. A warm hemolytic autoantibody was suspected. She was transfused two units of incompatible RBCs for a rapidly falling hemoglobin and symptomatic anemia. On Day 11, the total bilirubin rose to 3.5 mg per dL, and the lactate dehydrogenase was 1154 IU per L with a hemoglobin of 7.6 g per dL. Corticosteroids were begun. Studies of serum and an acid eluate revealed anti-At(a), but no other RBC antibodies. The patient stabilized, and further transfusion was avoided. CONCLUSION: Although anti-At(a) was previously described as being of uncertain clinical significance, this patient demonstrated the ability of the antibody to cause a severe delayed hemolytic transfusion reaction.     

Potassium-adsorption filter for RBC transfusion: a phase III clinical trial

BACKGROUND: Within the past 2 years, three cases of cardiac arrest just after rapid transfusion of RBCs preserved for over 7 days after 15-Gy irradiation were found. This severe complication caused transient hyperkalemia. To prevent potassium (K(+)) overload by RBC transfusion at the bedside, a K(+)-adsorption filter made of sodium polystyrene sulfonate was developed. STUDY DESIGN AND METHODS: After in vitro and animal safety and efficacy tests, a Phase III clinical trial was conducted with 65 patients given transfusions via the newly developed filter (filter group) and 37 patients in whom the filter was not used (control group) and transfusions were given at twice the usual flow rate (20 mL/min). RESULTS: More than 85-percent (94.4+/-3.8%) removal of K(+) in RBCs in mannitol-adenine-phosphate (MAP) that had been preserved for more than 14 days or that were used 3 days after 15-Gy irradiation (calculated K(+): 3.8+/-1.3 mEq/bag) was achieved in 82 of 83 bags of MAP RBCs in the filter group, with 79.6 percent removed in the other, even in rapid transfusions. RBC recovery 1 day after transfusion, determined by increments in RBCs, Hb, and Hct, were 24 and 0.4 x 10(4) per microL, 0.7 and 0.3 g per dL, and 1.6 and 0 percent, respectively, in the filter and control groups. No adverse transfusion reactions, such as hypotension, anaphylactoid reactions, or asthma-like attacks, were observed, except for one case of urticaria in the filter group. Mild fever (within 1 degrees C) after transfusion was observed in both groups. Serologic markers of hemolysis rose slightly in both groups, but there was no significant difference between the two groups. CONCLUSION: The newly developed K(+)-adsorption filter is useful, especially in a rapid transfusion setting.     

Clinical significance of RBC alloantibodies and autoantibodies in sickle cell patients who received transfusions

BACKGROUND: The clinical significance of alloimmunization to RBC antigens in sickle cell patients was analyzed by a retrospective review of the records of pediatric and adult sickle cell patients who received transfusions and who were followed over a 10-year period. STUDY DESIGN AND METHODS: Charts of pediatric and adult sickle cell patients followed at Schneider Children's Hospital (SCH) and Long Island Jewish Medical Center between 1989 and 1999 were retrieved. Patients followed at SCH were classified as pediatric, regardless of age. Data on transfusion history, alloimmunization, and transfusion reactions from 1990 were retrieved from computerized blood bank records. Transfusion history, development of alloantibodies and autoantibodies, and transfusion reactions were correlated with clinical evidence of hemolysis or other adverse reactions from the charts. All patients received ABO- and Rh-compatible blood transfusions for which a partial or extended antigen match was not performed. RESULTS: Among pediatric patients, 29 percent developed clinically significant alloantibodies, and 8 percent developed autoantibodies. Seven patients developed delayed hemolytic and/or serologic transfusion reactions, two with hyperhemolysis, two with clinical evidence of hemolysis, and three with serologic evidence only. The two patients with hyperhemolysis had received extended antigen-matched RBC transfusions to provide blood compatible with their existing antibodies. Among adult patients, 47.0 percent developed significant alloantibodies, and 9.7 percent developed autoantibodies. Five incidences of delayed hemolytic and/or serologic transfusion reactions occurred, one with hyperhemolysis and four with serologic evidence only. CONCLUSION: The alloimmunization rate is 29 percent in pediatric and 47 percent in adult sickle cell patients when partial or extended RBC antigen match is not performed. However, the delayed serologic and/or hemolytic transfusion reactions did not result in severe clinical outcome in most instances. The most important adverse event was hyperhemolysis, which may be triggered by a transfusion, but was not prevented by matching for RBC antigens. In most instances, the cause of hyperhemolysis was multifactorial.     

WBC reduction in RBC concentrates by prestorage filtration: multicenter experience

BACKGROUND: As universal leukocyte (WBC) reduction (ULR) is being considered as a new standard, few data are available on the performance of WBC-reduction filtration in routine practice. The performance of WBC-reduction in RBCs, using varied filtration practices, in meeting the current FDA requirement (<5 x 10(6)), Council of Europe (EC) recommendation, the proposed FDA requirement (<1 x 10(6)), and a more stringent proposal (<5 x 10(5)) for residual WBCs per RBC unit was assessed and compared. STUDY DESIGN AND METHODS: Participating facilities were the 11 sites of the Viral Activation Transfusion Study (VATS), a prospective study of the impact of transfusion with and without WBC-reduction on survival and HIV viral load in HIV-1-infected patients. Patients randomly assigned to undergo WBC reduction were required to receive RBCs < or =14 days old that had undergone prestorage (within 72 hours of collection) WBC-reduction filtration by a method devised to achieve a postfiltration WBC count of <5 x 10(6). Residual WBC quantitation was performed by PCR in the central VATS laboratory by using frozen WBC-reduced RBC samples obtained at issue for transfusion. RESULTS: A total of 1869 WBC-reduced RBC units were studied. Filtration practices varied within and between sites. There were significant differences in mean residual WBC counts at the 11 sites (p<0.001). Among the WBC-reduced RBC units, 0.8 percent exceeded 5 x 10(6) WBCs per unit, 8.3 percent exceeded 1 x 10(6) WBCs per unit, and 14.3 percent exceeded 5 x 10(5) WBCs per unit. CONCLUSION: Residual WBCs in WBC-reduced RBC units vary within and between sites. WBC reduction was successful, in that over 99 percent and 91 percent of VATS WBC-reduced RBC units met US and EC thresholds, respectively. However, the small but measurable failure rate indicates that not every unit will meet these guidelines.     

Hyperhemolysis syndrome in anemia of chronic disease

BACKGROUND: Occasional cases of delayed hemolytic transfusion reaction (DHTR) demonstrate severe and persistent hemolysis and are referred to as hyperhemolysis syndrome. This syndrome usually occurs in patients with sickle cell disease and possibly thalassemia who receive multiple transfusions. There are few such clinical reports in patients without hemoglobinopathies. CASE REPORT: A 67-year-old woman with anemia and a history of four previous transfusions was admitted with shortness of breath and a hematocrit (Hct) level of 27 percent. The patient was group O with a negative antibody screen. She received 1 unit of electronically cross-matched red blood cells (RBCs) and was discharged. Thirteen days later she returned to hospital with weakness and a Hct level of 23 percent. The antibody screen now demonstrated anti-K alloantibody. The direct antigloblulin test (DAT) was positive with both anti-immunoglobulin G and anti-complement (C3). Anti-K was recovered in the eluate. The previously transfused RBC unit was positive for presence of the K antigen. The patient's RBCs were negative for the presence of K antigen. Other laboratory data confirmed ongoing hemolysis, and a diagnosis of DHTR was made. She continued to display findings of active hemolysis for 9 more weeks requiring 19 units of RBCs. Thirty-four days after the original transfusion, her DAT remained positive and both the plasma sample and a RBC eluate demonstrated anti-K. CONCLUSION: The delayed hemolytic transfusion reaction with hyperhemolysis can occur among patients without hemoglobinopathies.     

Red blood cell alloimmunization in sickle cell disease: prevalence in 2010

BACKGROUND: Transfusion of red blood cells (RBCs) is frequently required for care of individuals with sickle cell disease (SCD). Alloimmunization rates are high and may be reduced by matching for RBC antigens that can cause alloimmunization. STUDY DESIGN AND METHODS: During the PROACTIVE Feasibility Study, patients with SCD age 2 years or older admitted for pain without acute chest syndrome were enrolled for possible randomization to preventive blood transfusion or standard care. Transfusion and antibody histories were obtained at each site, and antibody screening was done, to assess transfusion burden and alloimmunization prevalence. Participating sites were surveyed regarding antigen matching practice. RESULTS: A total of 237 patients (169 SS, 42 SC, 15 Sβ⁰‐thalassemia, 11 Sβ⁺‐thalassemia), 118 males and 119 females, were enrolled. Mean age was 19.3 years (range, 2.0‐68.0); there were 122 children and 115 adults. A total of 75.8% had received at least a single transfusion of RBCs before the study. Thirty‐four patients (14.4%) had a history of at least one alloantibody and 17 of these had more than one. When surveyed, 19 sites (83% of responders) reported antigen matching to at least include C, E, and K for transfusion of all patients with SCD. CONCLUSION: Though antigen typing before transfusion of people with SCD and providing antigen‐negative units is now widely employed by sickle cell centers, the alloimmunization rate remains quite high in contemporary sickle cell populations and may be due in large part to transfusions received at institutions not providing extended matching.     

Alloimmunization to transfused HOD red blood cells is not increased in mice with sickle cell disease

BACKGROUND: Increased rates of red blood cell (RBC) alloimmunization in patients with sickle cell disease may be due to transfusion frequency, genetic predisposition, or immune dysregulation. To test the hypothesis that sickle cell pathophysiology influences RBC alloimmunization, we utilized two transgenic mouse models of sickle cell disease. STUDY DESIGN AND METHODS: Transgenic sickle mice, which express human α and β^S globin, were transfused with fresh or 14‐day‐stored RBCs containing the HOD (hen egg lysozyme, ovalbumin, and human Duffy^b) antigen; some recipients were inflamed with poly(I : C) before transfusion. Anti‐HOD alloantibody responses were subsequently measured by enzyme‐linked immunosorbent assay and flow crossmatch; a cohort of recipients had posttransfusion serum cytokines measured by bead array. RESULTS: Both Berkeley and Townes homozygous (SS) and heterozygous (AS) mice had similar rates and magnitude of anti‐HOD RBC alloimmunization after fresh HOD RBC transfusion compared with control animals; under no tested condition did homozygous SS recipients make higher levels of alloantibodies than control animals. Unexpectedly, homozygous SS recipients had blunted cytokine responses and lower levels of anti‐HOD alloantibodies after transfusion of 14‐day stored RBCs, compared with control animals. CONCLUSIONS: In sum, homozygous β^S expression and the ensuing disease state are not alone sufficient to enhance RBC alloimmunization to transfused HOD RBCs in two distinct humanized murine models of sickle cell disease under the conditions examined. These data suggest that other factors may contribute to the high rates of RBC alloimmunization observed in humans with sickle cell disease.     

Transfusion and postoperative pneumonia in coronary artery bypass graft surgery: effect of the length of storage of transfused red cells

BACKGROUND: Various bioactive substances are released from white cell (WBC) granules into red cell (RBC) components in a time-dependent manner during blood storage. Some of these substances may have immunosuppressive effects and may contribute to transfusion-induced immunomodulation. RBCs transfused after prolonged storage may be associated with a higher incidence of postoperative infections than fresh RBCs. This hypothesis does not seem to have been investigated in a clinical study. STUDY DESIGN AND METHODS: The records of 416 consecutive patients undergoing coronary artery bypass graft operations at the Massachusetts General Hospital were reviewed. The association between the length of storage of the transfused RBCs, as well as the number of units of non-WBC-reduced allogeneic RBCs and/or platelets transfused, and the occurrence of postoperative pneumonia was calculated by logistic regression analyses adjusting for the effects of confounding factors. Among these were the numbers of days of intubation, days of impaired consciousness, and units of RBCs transfused. RESULTS: By Centers for Disease Control and Prevention criteria, pneumonia developed in 54 patients (13.0%). Among 269 patients given RBCs, the risk of pneumonia increased by 1 percent per day of increase in the mean storage time of the transfused RBCs (p<0.005). In an analysis of all patients, the risk of pneumonia increased by 5 percent per unit of non-WBC-reduced allogeneic RBCs and/or platelets received (p = 0.0584). CONCLUSION: After adjustment for the effects of the risk factors for pneumonia and the number of transfused RBCs, an association was observed between the length of storage of transfused RBCs and the development of postoperative pneumonia. This association should be investigated further in future studies of the outcomes of blood transfusion.     

Red Blood Cell Alloimmunization Mitigation Strategies

Hemolytic transfusion reactions due to red blood cell (RBC) alloantibodies are a leading cause of transfusion-associated death. In addition to reported deaths, RBC alloantibodies also cause significant morbidity in the form of delayed hemolytic transfusion reactions. These alloantibodies may also cause morbidity in the form of anemia, with compatible RBC units at times being unable to be located for highly alloimmunized patients, or in the form of hemolytic disease of the newborn. Thus, preventing RBC alloantibodies from developing in the first place, or mitigating the dangers of existing RBC alloantibodies, would decrease transfusion-associated morbidity and mortality. A number of human studies have evaluated the impact on RBC alloimmunization rates of providing partially phenotypically or genotypically matched RBCs for transfusion, and a number of animal studies have evaluated the impact of single variables on RBC alloimmunization. The goal of this review is to take a comprehensive look at existing human and animal data on RBC alloimmunization, focusing on strategies that may mitigate this serious hazard of transfusion. Potential factors that impact initial RBC alloimmunization, on both the donor and recipient sides, will be discussed. These factors include, but are not limited to, exposure to the antigen and an ability of the recipient's immune system to present that antigen. Beyond these basic factors, coexisting “danger signals,” which may come from the donor unit itself or which may be present in the recipient, also likely play a role in determining which transfusion recipients may become alloimmunized after RBC antigen exposure. In addition, to better understanding factors that influence the development of RBC alloantibodies, this review will also briefly discuss strategies to decrease the dangers of existing RBC alloantibodies.     

Transfusion-related sepsis due to Serratia liquefaciens in the United States

BACKGROUND: Severe, often fatal, transfusion reactions due to bacterial contamination of blood components continue to occur. Serratia liquefaciens, an unusual human pathogen, is a recently recognized potential cause of transfusion-related sepsis. CASE REPORTS: Five episodes of transfusion-related sepsis and endotoxic shock due to S. liquefaciens were reported to the CDC from July 1992 through January 1999. One episode has been described. The remaining four, all fatal, are described here: three associated with RBC transfusion and one associated with transfusion of platelets. In each instance, the source of contamination could not be found. The implicated units tended to be older (mean RBC age 28 days), and visual discoloration was noted in each RBC unit, although usually in retrospect. CONCLUSION: S. liquefaciens is an increasingly recognized cause of transfusion-related sepsis and is associated with a high mortality rate. S. liquefaciens can contaminate both RBCs and platelets, but the mechanism(s) of contamination remain unknown. Increased attention to pretransfusion visual inspection may avert the transfusion of some S. liquefaciens-contaminated RBC units. However, more sensitive rapid diagnostic tests are needed to further reduce the risk of transfusion-related sepsis and endotoxic shock.     

Acquired hemoglobin variants and exposure to glucose‐6‐phosphate dehydrogenase deficient red blood cell units during exchange transfusion for sickle cell disease in a patient requiring antigen‐matched blood

Red blood cell exchange (RBCEx) is frequently used in the management of patients with sickle cell disease (SCD) and acute chest syndrome or stroke, or to maintain target hemoglobin S (HbS) levels. In these settings, RBCEx is a category I or II recommendation according to guidelines on the use of therapeutic apheresis published by the American Society for Apheresis. Matching donor red blood cells (RBCs) to recipient phenotypes (e.g., C, E, K‐antigen negative) can decrease the risk of alloimmunization in patients with multi‐transfused SCD. However, this may select for donors with a higher prevalence of RBC disorders for which screening is not performed. This report describes a patient with SCD treated with RBCEx using five units negative for C, E, K, Fya, Fyb (prospectively matched), four of which were from donors with hemoglobin variants and/or glucose‐6‐phosphate dehydrogenase (G6PD) deficiency. Pre‐RBCEx HbS quantification by high performance liquid chromatography (HPLC) demonstrated 49.3% HbS and 2.8% hemoglobin C, presumably from transfusion of a hemoglobin C‐containing RBC unit during a previous RBCEx. Post‐RBCEx HPLC showed the appearance of hemoglobin G‐Philadelphia. Two units were G6PD‐deficient. The patient did well, but the consequences of transfusing RBC units that are G6PD‐deficient and contain hemoglobin variants are unknown. Additional studies are needed to investigate effects on storage, in‐vivo RBC recovery and survival, and physiological effects following transfusion of these units. Post‐RBCEx HPLC can monitor RBCEx efficiency and detect the presence of abnormal transfused units. J. Clin. Apheresis 28:325–329, 2013. © 2013 Wiley Periodicals, Inc.     

Length of storage of transfused red cells and postoperative morbidity in patients undergoing coronary artery bypass graft surgery

BACKGROUND: The transfusion of old red cells (RBCs) may be associated with reduced delivery of oxygen to tissues and an increased risk of transfusion complications. The association of postoperative morbidity with the length of storage of perioperatively transfused RBCs was studied in 268 consecutive patients receiving a blood transfusion for coronary artery bypass graft surgery. STUDY DESIGN AND METHODS: The postoperative length of hospitalization, the postoperative length of stay in the intensive care unit, and the length of endotracheal intubation after the day of the operation were used as surrogate measures of global postoperative morbidity. The length of storage of the oldest transfused RBC unit, the mean length of storage of the oldest and second oldest RBC units, and the mean length of storage of all RBC units transfused to each patient were tested for association with the three outcome variables. Multiple linear regression analysis and Cox proportional-hazard analysis were used to adjust for the effects of confounding factors that pertained to each patient's severity of illness and the difficulty of each operation. RESULTS: There were no significant associations after adjustment for the effects of confounding factors. CONCLUSION: This study did not corroborate the previously reported association between transfusion of old RBCs and increased morbidity. However, there is surprisingly little research on the clinical outcomes of the transfusions of old RBCs, and this hypothesis should be investigated further.     

Detection of anti-D in D- recipients transfused with D+ red blood cells

BACKGROUND: The D antigen is highly immunogenic, requiring only a small quantity of transfused red blood cells (RBCs) to cause alloimmunization in D- immunocompetent recipients. The relatively low sensitization rate in oncology patients transfused with D+ platelets is well documented. A study of the alloimmunization rate of primarily nononcology D- recipients transfused with D+ RBCs was undertaken. STUDY DESIGN AND METHODS: Transfusion service records were examined to identify D- recipients who were not alloimmunized to the D antigen and who had a follow-up antibody screen performed at least 10 days after the initial D+ RBC transfusion(s). The age and sex of the recipients, date and number of D+ RBC transfusion(s) and their leukoreduction status, all subsequent serologic investigations, and the hospital ward where the units were issued were recorded. RESULTS: There were 98 study-eligible recipients identified who received a total of 445 D+ RBC units. The mean follow-up length was 182 days. Most recipients (87%) had antibody screens performed more than 21 days after the initial D+ RBC transfusion. In total, 24 recipients made 44 new alloantibodies: 22 anti-D (22%), 11 anti-E, 5 anti-C, 2 anti-K, and 1 each of anti-Kp(a), anti-Jk(a), anti-Bg, and anti-Fy(b). The rate of anti-D alloimmunization among recipients of entirely leukoreduced D+ units was 13 percent (1/8). Reexposure to D+ RBCs after the initial bleeding episode did not increase the rate of alloimmunization. CONCLUSIONS: The 22 percent rate of anti-D alloimmunization in patients requiring urgent RBC transfusion was intermediate between the rates previously reported for D- oncology patients transfused with D+ RBCs and that in immunocompetent volunteer recipients.     

Alloimmunization in transfused patients with constitutional anemias in Norway

Background and ObjectivesThe status of red blood cell alloimmunization in patients with constitutional anemias including hemoglobinopathies is not known in Norway. The study objective was to investigate the impact of a strategy based on phenotype-matching for C, c, E, e, K, Jka, Jkb, Fya, Fyb, S and s on alloimmunization.Materials and MethodsWe reviewed transfusions of 40 patients retrospectively using the computerized blood bank management system and medical records; including diagnosis, age at start of transfusion therapy, gender, number and age of packed red blood cell units transfused, follow-up time, phenotypes of the donors and patients, antigen-negative patients exposed to antigen-positive packed red blood cell units, transfusion reactions and alloantibody specificities.ResultsForty patients received 5402 packed red blood cell units. Alloimmunization frequency was 20 % for the whole group, being 7%, 25 % and 30 % in patients with sickle cell disease (n = 14), thalassemia (n = 16) and other conditions (n = 10), respectively. The alloantibodies detected were anti-E, -c, -C, -Cw, -K, -Jka and -Lua.ConclusionGood communication between the clinicians and the transfusion services is essential for successful management of patients with constitutional anemias. Providing full phenotype-matched units was not always possible. Extended pheno-/genotyping before the first transfusion and providing antigen-negative units for antigen-negative patients for at least C, c, E and K in every red cell transfusion would probably have reduced the alloimmunization rate. Non-phenotype-matched transfusions seem to be the main reason for alloimmunization. Finding markers for identifying responders prone to alloimmunization will ensure targeted transfusion strategies.     

Additional red blood cell alloantibodies after blood transfusions in a nonhematologic alloimmunized patient cohort: is it time to take precautionary measures?

BACKGROUND: Red blood cell (RBC) alloimmunization is common in transfused patients. Most studies report on the rate of alloimmunization in chronically transfused patients, which can be as high as 60 percent. Less is known on the incidence of clinically relevant antibodies in accidentally transfused patients. Because the probability of repeat transfusion increases with longer life expectancy, it was wondered to which extend non-chronically transfused alloimmunized patients are prone to form additional antibodies after repeat transfusion events. STUDY DESIGN AND METHODS: A 20-year retrospective multicenter study was performed analyzing additional alloantibody formation, against the RH, KEL, FY, JK, and MNS blood group systems. RESULTS: After additional transfusions, 21.4 percent of 653 patients produced additional antibodies, resulting in 157 new antibody specificities. At the end of the study 33.4 percent of patients had multiple antibodies. Eighty of 140 patients (57%) who formed additional antibodies did so after one transfusion episode of a median of 2 units of RBCs. Based on the antigen profile of 316 patients, 83 percent of antibodies could have been prevented by extended matching for the C, E, c, K, Fy(a), and Jk(a) antigens. Considering the current available donors in our region, 1 to 10 percent of potential donors would be available for 39 percent of patients and greater than 10 percent of potential donors for 61 percent of patients. CONCLUSION: It has been shown that nonhematooncologic alloimmunized patients are high antibody responders, with a more than 20 times increased risk to form antibodies compared to first-time alloimmunization risk. If extended matching for C, c, E, K, Fy(a), and Jk(a) antigens in the future is considered, this group should be taken into account.