Clinical predictors of alloimmunization after red blood cell transfusion

BACKGROUND: Development of new red blood cell (RBC) alloantibodies (alloimmunization) is one of the most frequent adverse reactions after an RBC transfusion. Few studies have investigated clinical risk factors for alloimmunization. STUDY DESIGN AND METHODS: In this case-control study, the characteristics of all patients in whom alloimmunization occurred for the first time after an RBC transfusion in two hospitals between January 1, 2003, and May 5, 2005, were examined and compared to a randomly selected control group who received RBC transfusions in the same hospitals during the same period without alloimmunization. Odds ratios (ORs) for the association between these characteristics and alloimmunization were calculated and analyzed with a logistic regression model. RESULTS: Eighty-seven cases were found, and 101 controls were selected. Female sex (OR, 1.89; 95% confidence interval [CI], 1.05-3.38), diabetes mellitus (OR, 2.15; 95% CI, 0.91-5.05), solid malignancy (OR, 2.07; 95% CI, 1.00-4.30), and previous allogeneic hematopoietic peripheral blood progenitor cell (PBPC) transplantation (OR, 2.24; 95% CI, 0.64-7.81) were associated most strongly with alloimmunization, whereas lymphoproliferative disorders (OR, 0.33; 95% CI, 0.13-0.81) and symptomatic atherosclerosis (OR, 0.52; 95% CI, 0.25-1.08) were associated with the absence of alloimmunization. All of these associations except for female sex became stronger after adjustment for possible confounders. CONCLUSION: Female sex, diabetes mellitus, solid malignancy, and previous allogeneic PBPC transplantation seem to be risk factors for alloimmunization, whereas lymphoproliferative disorders and symptomatic atherosclerosis seem to protect against it. Further studies are needed to confirm these associations and investigate underlying mechanisms.     

IgG red blood cell autoantibodies in autoimmune hemolytic anemia bind to epitopes on red blood cell membrane band 3 glycoprotein.

Red blood cell (RBC) autoantibodies from patients with IgG warm-type autoimmune hemolytic anemia were labeled with iodine 125 and their RBC binding behavior characterized. Epitope-bearing RBC membrane polypeptides were identified after autoantibody immunoprecipitation of labeled membranes and immunoblotting. Immunoaffinity isolation of labeled membrane proteins with 12 different IgG hemolytic autoantibodies with protein A-agarose revealed a major polypeptide at Mr 95 to 110 kd, which coelectrophoresed on sodium dodecylsulfate-polyacrylamide gel electrophoresis with a membrane component isolated with sheep IgG anti-band 3. Immunoprecipitation studies with chymotrypsinized RBCs resulted in the recovery of two labeled membrane polypeptides with molecular weights characteristically resulting from the chymotryptic fragmentation of band 3. Immunoblotting with sheep IgG anti-band 3 of the immunoprecipitated polypeptides confirmed that hemolytic autoantibody binding led to recovery of band 3 or its fragments. Two 125I-labeled IgG hemolytic autoantibodies showed binding behavior consistent with epitope localization on band 3. The labeled RBC autoantibodies bound immunospecifically to all types of human RBC tested, including those of rare Rh type (Rh-null, D--) at a site density of approximately 10(6) per RBC. The 125I-IgG in two labeled autoantibodies was 84% and 92% adsorbable by human and higher nonhuman primate RBCs. Antigen-negative animal RBC bound less than 10% (dog, 2.6%; rhesus monkey, 7.4%), consistent with immunospecific RBC binding. IgG-1 was the major subclass in five autoantibodies tested; one of six fixed complement; and autoantibody IgG appeared polyclonal by isoelectric focusing. We conclude that IgG eluted from RBCs of patients with autoimmune hemolytic anemia consists predominantly of a single totally RBC-adsorbable antibody population that binds to antigenic determinants on band 3. Unlike RBC autoantibodies from antiglobulin-positive normal blood donors, autoantibodies from patients with autoimmune hemolytic anemia did not show Rh-dependent properties as judged by antigen site density, absence of differential binding to RBC of different Rh phenotypes, failure to immunoprecipitate 30 kd Rh-epitope bearing membrane polypeptides, absence of multiple antibody populations, and the lack of a significant nonadsorbable IgG population that has been associated with the presence of antiidiotypic IgG. The absence of antiidiotypic IgG in hemolytic autoantibodies may be a contributory factor in the development of autoimmune hemolytic anemia.     

Plasma exchanges do not increase red blood cell transfusion efficiency in severe autoimmune hemolytic anemia: a retrospective case-control study

Severe autoimmune hemolytic anemia (AIHA) can cause life-threatening hemolysis requiring red blood cell transfusions (RBT). The efficiency of RBT could be improved with the use of plasma exchanges (PEx) before RBT. The objective of this study was to assess the effectiveness of PEx in severe AIHA of adults. All adult patients with severe AIHA requiring RBT were included in this single center retrospective case-control study. The end point was change in hemoglobin (Hb) level after RBT, depending on whether PEx was done (experimental group) or not (control group). Thirty-one sessions of RBT following PEx were performed on the 5 patients of the experimental group and were compared with the 7 sessions of BT without PEx performed on the 4 patients of the control group. Despite a lower mean Hb value before the session of RBT (5.7 g/dl vs. 7.2 g/dl, P = 0.04) in the control group, the mean Hb value 5 (4-7) days following RBT (8.7 g/dl vs. 8.6 g/dl, P = 0.85) was not different in the experimental and in the control group, respectively. In a second analysis in which each patient was his own control (31 sessions of RBT following PEx vs. 51 sessions of RBT alone), the gain in Hb was not different (1.4 g/dl vs. 1.9 g/dl, P = 0.67). When RBT are required in severe AIHA of adults, the use of a single PEx before BT does not increase the efficiency of RBT based on day 5 evaluation.     

自体外周血干细胞移植联合利妥昔单抗治疗自身免疫性溶血性贫血——附1例报告

目的:探讨自体外周血干细胞移植(autologous peripheral blood stem cell transplantation, APBSCT)联合抗CD20单克隆抗体利妥昔单抗治疗自身免疫性溶血性贫血(autoimmune hemolytic anemia,AIHA)的疗效.方法:对1例激素依赖的AIHA患者进行APBSCT同时联合使用利妥昔单抗.采用环磷酰胺4g/m2联合非格司亭5μg/(kg·d)动员患者的外周血干细胞,然后予环磷酰胺50 mg/(kg·d)共4日,预处理后回输保存的外周血干细胞,共回输单个核细胞2.12×108/kg,CD34 细胞1.48×106/kg,回输后分别于第1日及第8日予利妥昔单抗375 mg/m2行体内净化.结果:移植后患者造血恢复顺利,于第8日中性粒细胞绝对数超过0.5×109/L,第9日血小板超过20×109/L.患者在移植过程中血红蛋白最低降至82g/L,于第16日升至90g/L,网织红细胞降至正常,胆红素恢复正常.随访13个月,造血功能恢复良好,血红蛋白为127g/L,网织红细胞正常,胆红素正常,抗人球蛋白试验转阴,仍在继续随访中.结论:APBSCT联合利妥昔单抗是治疗激素依赖的AIHA的有效方法之一.     

Delayed hemolytic transfusion reaction with hyperhemolysis after first red blood cell transfusion in child with β‐thalassemia: challenges in treatment

BACKGROUND: Delayed hemolytic transfusion reaction (DHTR) can manifest with hyperhemolysis, a serious complication of red blood cell (RBC) transfusions. This has mostly been described in sickle cell anemia but occasionally in β‐thalassemia. Treatment is challenging; immunosuppressive medication has been reported to be useful by some but not others. CASE REPORT: A 1.5‐year‐old girl with homozygous β‐thalassemia was put on a regular RBC transfusion program because of anemia with stunted growth and abnormal bone development. After the first transfusion she developed DHTR with hyperhemolysis. Further RBC transfusions could not be avoided. Despite treatment with prednisone, immunoglobulins, rituximab, and azathioprine hemolysis continued. She received an allogeneic bone marrow transplantation after conditioning using cyclophosphamide, treosulfan, melfalan, and ATG. The transplantation was followed by treatment with cyclosporin A, methotrexate, and prednisone. Because of poor engraftment and later rejection, she received a retransplantation after conditioning using fludarabine instead of cyclophosphamide and was subsequently treated with prednisone, but hemolysis continued. Only after splenectomy did she no longer need RBC transfusions and the direct antiglobulin test turned negative. DISCUSSION AND CONCLUSION: Treatment of DHTR remains challenging. The role of immunosuppressive medication such as azathioprine, cyclosporin A, and rituximab remains to be seen. Splenectomy may be helpful. Mainstay is to minimize RBC transfusions as much as possible.     

Exacerbation of autoimmune hemolytic anemia associated with pure red cell aplasia after COVID-19: A case report

Autoimmune hemolytic anemia (AIHA) and pure red cell aplasia (PRCA) are rare complications of coronavirus disease 2019 (COVID-19). Herein, we report the case of a 28-year-old Japanese man who showed severe AIHA exacerbation associated with PRCA after COVID-19. AIHA was diagnosed and maintained for 5 years. Approximately 4 weeks after COVID-19, the patient developed severe anemia (hemoglobin level, 3.4 g/dL). Laboratory test results confirmed hemolytic exacerbation of IgG-mediated warm-type AIHA. Despite the hemolysis phase, the bone marrow revealed extreme hypoplasia of erythroblasts with a decreased reticulocyte count, similar to that observed in patients with PRCA. During oral prednisolone treatment, the patient recovered from anemia and showed increased reticulocyte count and reduced hypoplasia of marrow erythroblasts. Exacerbation of AIHA and PRCA was triggered by COVID-19 because other causes were ruled out. Although this case report highlights that COVID-19 could lead to hematological complications such as AIHA and PRCA, the exact mechanisms remain unclear.     

Plasmapheresis treatment in 3 simultaneously occurring autoimmune diseases: Hashimoto thyroiditis with hyperthyroidism, autoimmune thrombopenia and autoimmune hemolytic anemia

A 49 year-old women with a 2-year history of a Coombs-positive autoimmune haemolytic anaemia was hospitalized with Hashimoto's thyroiditis and thyrotoxic crisis. The clinical course was further complicated by an autoimmune thrombocytopenia. Primary resection of the thyroid thus seemed to be too risky, so we decided to perform therapeutic plasma exchange. This led to clinical improvement, enabling us to perform a thyroidectomy. The present investigation reveals the high efficiency of plasmapheresis in the treatment of combined autoimmune diseases. Therapeutic plasma exchange resulted in a reduction of both the relevant autoantibodies and the level of circulating thyroid hormones.     

Coombs' negative immune hemolytic anemia with anti-E occurring in the red blood cell eluate of an E-negative patient

A previously untransfused 20-year-old man presented with a seven day history of malaise, fatigue, jaundice, dark urine and splenomegaly. Hemolytic anemia was indicated by a hemoglobin of 8.7 mg/dl, reticulocyte count 8 per cent, Lactic dehydrogenase 389 iu/L, bilirubin 4.3 mg/dl (direct 0.1 mg/dl), and undetectable haptoglobins. Tests for nonimmunologic mediated hemolytic anemia were negative. The direct antiglobulin test (DAT) was repeatedly negative with polyspecific, anti-IgG, -IgA, -IgM and anti-C3 antisera. The patient's serum contained a weak anti-I, anti-E strongly reactive by indirect antiglobulin test (IAT) and an antibody reactive against all cells tested. The latter antibody reacted weakly by the IAT but strongly against enzyme-treated cells (Titer 160). Eluates from the patient's red blood cells only reacted with E+ red blood cells. The patient typed E negative. He was treated for warm autoimmune hemolytic anemia (AIHA) with high doses of prednisone. By the twelfth day his response allowed the medication to be tapered and by one month from the onset of treatment laboratory studies had returned to normal. The DAT remained negative, however, following recovery, anti-E could not be eluted from the red blood cells. Anti-E remained in his serum and the titer of the enzyme reactive antibody had decreased to 16. It is suggested that the anti-“E-like” antibody may represent auto anti-Hr preferentially reacting with E+ red blood cells. A unique feature in the case is the presence of a specific antibody eluted from cells that appear to lack that antigen in a DAT-negative patient with AIHA.     

Studies of in vitro red cell autoantibody production in normal donors and in patients with autoimmune hemolytic anemia

The in vitro production of red cell autoantibodies (RBC AuAbs) has been investigated for better understanding of the pathogenesis of autoimmune hemolytic anemia (AIHA). Peripheral blood mononuclear cells (PBMNCs) were isolated and cultured for 14 days with or without added pokeweed mitogen (PWM), autologous RBCs, methyldopa, procainamide, and alpha-methylnorepinephrine. Also, isolated B cells were infected with Epstein-Barr virus (EBV) to produce polyclonal B-cell lines. Supernatants were tested for IgG and IgM RBC AuAbs by use of 125I-staphylococcal protein A (SPA). RBC AuAbs were detected in PBMNC cultures without additives to the culture medium of four of eight patients who had warm-antibody AIHA or a positive direct antiglobulin test (DAT) without hemolytic anemia. In two of these patients, RBC AuAb production was augmented by the addition of PWM, and in two additional patients, RBC AuAbs were detected only after the addition of PWM. Supernatants from PBMNC cultures from three of four normal donors produced RBC AuAbs independent of the presence of PWM; in two of these subjects, PWM augmented production of RBC AuAbs. PBMNC cultures from three DAT-negative patients with systemic lupus erythematosus produced RBC AuAbs, one in the presence of PWM and two in its absence. With one exception, there was no augmentation of AuAb production by the addition to the culture system of autologous RBCs or drugs. EBV infection of B cells from four patients with AIHA and four normal persons yielded B-cell lines secreting RBC AuAbs. The quantity of RBC AuAb after a 24-hour culture of EBV-transformed B cells was significantly greater in cultures from four patients who had AIHA than in cultures from four normal persons.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microvascular response to red blood cell transfusion in patients with severe sepsis

OBJECTIVES: Microvascular alterations may play a role in the development of multiple organ failure in severe sepsis. The effects of red blood cell transfusions on microvascular perfusion are not well defined. We investigated the effects of red blood cell transfusion on sublingual microvascular perfusion in patients with sepsis. DESIGN: Prospective, observational study. SETTING: A 31-bed, medical-surgical intensive care unit of a university hospital. PATIENTS: Thirty-five patients with severe sepsis requiring red blood cell transfusions. INTERVENTIONS: Transfusion of one to two units of leukocyte-reduced red blood cells. MEASUREMENTS AND MAIN RESULTS: The sublingual microcirculation was assessed with an Orthogonal Polarization Spectral device before and 1 hr after red blood cell transfusion. Red blood cell transfusions increased hemoglobin concentration from 7.1 (25th-75th percentile, 6.7-7.6) to 8.1 (7.5-8.6) g/dL (p < .01), mean arterial pressure from 75 (69-89) to 82 (75-90) mm Hg (p < .01), and oxygen delivery from 349 (278-392) to 391 (273-473) mL/min.M (p < .001). Microvascular perfusion was not significantly altered by transfusion, but there was considerable interindividual variation. The change in capillary perfusion after transfusion correlated with baseline capillary perfusion (Spearman-rho = -.49; p = .003). Capillary perfusion was significantly lower at baseline in patients who increased their capillary perfusion by >8% compared with those who did not (57 [52-64] vs. 75 [70-79]; p < .01), while hemodynamic and global oxygen transport variables were similar in the two groups. Red blood cell storage time had no influence on the microvascular response to red blood cell transfusion. CONCLUSIONS: The sublingual microcirculation is globally unaltered by red blood cell transfusion in septic patients; however, it can improve in patients with altered capillary perfusion at baseline.     

Doppler assessment of renal blood flow velocity waveforms in the anemic fetus before and after intravascular transfusion for severe red cell alloimmunization.

Image-directed pulsed Doppler ultrasonography demonstrated a decrease in the pulsatility index of the renal artery in 9 anemic fetuses (less than 30 weeks, menstrual age) soon after intravascular transfusion. The pulsatility index returned to pretransfusion values the day following the transfusion. End diastolic blood velocity in the renal artery could not be measured before the transfusion, was detectable immediately after the procedure, and was again nonmeasurable one day after the transfusion. These data suggest an increase in renal blood flow in the anemic fetus soon after intravascular transfusion to eliminate excess fluid.     

Fatal disseminated intravascular coagulation and pulmonary thrombosis following blood transfusion in a patient with severe autoimmune hemolytic anemia and human immunodeficiency virus infection

BACKGROUND: Autoimmune hemolytic anemia (AIHA) has rarely been reported in association with human immunodeficiency (HIV) infection and never as a presenting manifestation. Similarly, disseminated intravascular coagulation (DIC) is a very infrequent complication of HIV infection. CASE REPORT: An unusual patient is described who at the time of presentation with severe AIHA was found to be HIV positive. Shortly thereafter, he developed DIC, pulmonary thrombi, and right heart failure that proved fatal, in spite of intensive supportive measures. CONCLUSION: Although the etiology of the DIC and pulmonary thrombi could not be established, they are most likely related to aggressive transfusion therapy, with associated intravascular hemolysis.