Background Transfusion is a cornerstone of the management of sickle cell disease but carries a high risk of hemolytic transfusion reaction, probably because of differences in erythrocyte antigens between blood donors of Western descent and patients of African descent. cases of delayed hemolytic transfusion reactions between 2006 and 2009 in the database of the Necker Hospital, France. All patients experienced received cross-matched reddish cell models compatible in the ABO, RH, and KEL systems. We examined the medical charts in the computerized blood transfusion databases. All patients were admitted to the rigorous care unit. We progressively adopted the following strategy: intravenous immunoglobulins, and darbopoietin alpha when the reticulocyte count was below 150109/L, without further blood transfusion during the acute episode unless absolutely necessary. Results The median time between the transfusion and the diagnosis of delayed hemolytic transfusion reaction was six days. All patients experienced severe bone pain; all but one experienced a high-grade fever. Five patients experienced hemoglobin levels less than than 4g/dL and 3 experienced reticulocytopenia. In 5 BMY 7378 patients, no new antibody BMY 7378 was found; one individual experienced weakly reactive antibodies. Only 2 patients experienced new allo-antibodies possibly responsible for the delayed hemolytic reaction. Conclusions The initial symptoms of delayed hemolytic transfusion reaction were complex and mimicked other complications of sickle cell disease. In most of our cases, no new antibody was recognized, which underlines the complexity of the pathophysiology of this syndrome. variant allele, producing a partial C antigen. Blood group evaluation in the RH system showed no decrease in the expression of this variant antigen. Patient 5 experienced a serum anti-M antibody before the transfusion and received M-negative cross-matched models. After onset of the DHTR, only weak reactions were evidenced, with no detectable specificity. BMY 7378 The DAT was unfavorable. Patient 6 experienced no prior history of DHTR but experienced a weakly reactive screening test with no Rabbit polyclonal to AKAP5. detectable specificity. The RH phenotype was normal. The post-DHTR screening test showed anti-D and anti-S antibodies, and the DAT was IgG-positive. This individual experienced received D+, S+ RBC models. In this case, anti-S and anti-D antibody production could be the cause of the DHTR. Molecular analysis showed a partial D antigen (DAR variant). Finally, patient 8 experienced experienced a DHTR in 2008. Her phenotype was D+C-E-c+e+, K-, Fya-Fyb-, S-s+, Lea-Leb-. The DHTR in 2008 occurred after a transfusion of 5 models, one of which was Leb+ and another S+. All models were D-, E-, C-, and Fya-. The only antibody detected after the DHTR was anti-Leb. In 2010 2010, before a tonsillectomy, she received 3 models including two Fya+, BMY 7378 Fyb+ models and one D+ unit. She developed new antibodies (anti-D, anti-C, anti-e, anti-Fy3, and anti-Kpa) during this second DHTR episode. Molecular analysis showed poor D type 4, which could be considered a partial D antigen. Treatments and outcomes (Table 3) Table 3. Treatments and outcomes. The first 3 patients experienced DHTRs in 2006, when we experienced no standardized protocol for managing DHTRs in SCD patients. Given that the minimal Hb levels were not very low (4.5 to 5.9 g/dL), no specific treatment was given. A spontaneous favourable end result was seen in all 3 patients. The next 5 cases occurred in 2009 2009 and 2010. Diagnosis was rapid, and the Hb levels at diagnosis ranged from 3.7 to 8.6 g/dL. Treatment for DHTR was started immediately and consisted of corticosteroids in one patient (patient 6), IVIg in 3 patients (patients 4, 5 and 7), and both in one patient (patient 8). Three patients (patients 4, 5 and 8) experienced reticulocytopenia (100109/L, 86109/L, and 36109/L) and received erythropoietin. Hb levels continued to decrease in 6 patients in the days following diagnosis and reached a median minimum value of 3.60 g/dL (1.9C5.9) after a median of two days (range 1C5). In individual 4, the Hb level plateaued at about 4 g/dL before dropping abruptly to 1 1.9 g/dL. Usually, the drop in Hb level halted one day after the end of the clinical hemoglobinuria. A further transfusion was considered BMY 7378 indispensable in patients 4 and 5, whose Hb levels just before the repeat transfusion were 1.9 g/dL and 3.5 g/dL, respectively. Both patients received IVIg before the new transfusion which was well tolerated with no further hemolytic reaction. The patients who experienced a fever received intravenous cefo-taxime (n=6) or ceftriaxone (n=1). The antibiotics were usually started after the.