Favorable outcome without corticosteroids during post-artesunate delayed hemolysis with positive direct antiglobulin test in severe imported Plasmodium falciparum malaria, France.

OBJECTIVES: Positive direct antiglobulin tests (DATs) have been reported in cases of post-artesunate delayed hemolysis (PADH), but the causal role of auto-immune hemolysis remains unclear. We aimed to analyze a cohort of patients with PADH and DAT during severe malaria. METHODS: We describe PADH and DAT results in a 7-year multi-center retrospective cohort of patients receiving artesunate for severe imported malaria. RESULTS: Of 337 patients treated with artesunate, 46 (13.6%) had at least one DAT result within 30 days of treatment initiation, and 25/46 (54.3%) had at least one positive DAT. Among 40 patients with available data, 17 (42.5%) experienced PADH. Patient characteristics were similar for patients with a positive or negative DAT, and DAT positivity was not associated with PADH occurrence (P = 0.36). Among patients, 5/13 (38.5%) with a positive DAT after day 7 experienced PADH, compared to 10/13 (76.9%) of those with a negative DAT after day 7 (P = 0.11). Overall, 41% of patients required blood transfusions, and outcome was favorable without corticosteroids, even in cases of PADH. CONCLUSIONS: DAT does not appear to be a marker of PADH, but rather an indirect marker of an immune-mediated mechanism. DAT positivity should not lead to the administration of systemic corticosteroids during PADH.

Favorable Outcome of an Exclusively Posttransplant Prophylactic Strategy After Heart Transplantation in Recipients With High Immunological Risk.

BACKGROUND: Management of the increasing number of sensitized heart transplant candidates has become a recurrent issue. Rather than using pretransplant desensitization therapies, we used a posttransplant prophylactic strategy. Our aim was to describe outcomes in transplant recipients with preformed donor-specific anti-HLA antibodies (pfDSA) managed with this strategy. METHODS: A posttransplant protocol was applied to patients transplanted with pfDSA, consisting of perioperative management of DSA (polyvalent immunoglobulins +/- perioperative plasmapheresis sessions, according to DSA level, as well as induction therapy) and systematic treatment of subsequent antibody-mediated rejection (AMR), even when subclinical. We performed a retrospective analysis of this prospective protocol. The study included all consecutive first recipients of a noncombined heart transplant performed between 2009 and 2015 at our center. The primary endpoint was all-cause mortality. Secondary endpoints included primary graft dysfunction, early posttransplant bleeding, rejection, and cardiac allograft vasculopathy-free survival. RESULTS: A total of 523 patients were studied, including 88 (17%) and 194 (37%) transplanted with DSA mean fluorescence intensity (MFI) of 500 to 1000 and greater than 1000, respectively. The median follow-up period was 4.06 years. Survival was not significantly different between groups. Rejection-free survival was worse in patients with pfDSA MFI >1000, evidenced by a fourfold increase in the risk of antibody-mediated rejection. The incidence of primary graft dysfunction and cardiac allograft vasculopathy-free survival did not significantly differ between groups. Perioperative plasmapheresis increased the risk for transfusion of packed red blood cells. CONCLUSIONS: This exclusively posttransplant prophylactic strategy achieved favorable outcomes in heart transplant recipients with pfDSA.

Severe hemolysis after plasma transfusion in a neonate with necrotizing enterocolitis, Clostridium perfringens infection, and red blood cell T-polyagglutination.

BACKGROUND: Red blood cell (RBC) Thomsen-Friedenreich antigen exposure (T activation) in infants with necrotizing enterocolitis (NEC) has occasionally been associated with posttransfusional intravascular hemolysis thought to be due to anti-T antibodies in the donor plasma. STUDY DESIGN AND METHODS: We describe an infant with NEC and Clostridium perfringens infection complicated by severe hemolysis after plasma transfusion. After this case, infants with confirmed NEC were prospectively evaluated for T activation. We checked for hemolysis in patients with T activation receiving plasma-containing blood products. RESULTS: The infant had received 80 mL of fresh-frozen plasma (FFP). His RBCs displayed strong T activation, and agglutination was observed with four of six ABO-compatible FFP units. A direct antiglobulin test was negative. IgM-class anti-T antibodies were present in small amounts (titer of 8) in the transfused FFP. Anti-T antibodies from the blood donor were not hemolytic in vitro. In the prospective study, T activation was observed in three of 28 infants with NEC (11%). One infant presented moderate T activation and two infants presented very strong T activation but only moderate decreases in sialic acid expression on the RBC membrane. These three infants presented no signs of hemolysis after transfusion with unwashed blood products or FFP. CONCLUSION: Anti-T antibodies are unlikely to be the etiologic factor for the hemolytic reactions observed in infants with NEC and T activation. Massive RBC desialylation and the direct action of bacterial toxins are more probable causes. Strict avoidance of plasma-containing blood products does not seem justified in these infants.

Immunohematologic tolerance of chronic transfusion exchanges with erythrocytapheresis in sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) has become a major public health issue. Hydroxyurea and red blood cell (RBC) transfusion are the cornerstone treatments. Erythrocytapheresis (ECP) is an automated method for transfusion exchange. Given that ECP requires more blood than conventional transfusion, there is concern about alloimmunization and hemolytic transfusion reactions. We evaluate the incidence of hemolytic transfusion reactions and alloimmunization rates in patients receiving conventional blood transfusions and in patients participating in long-term blood exchange programs with ECP. STUDY DESIGN AND METHODS: All hemolytic transfusion reactions and alloimmunizations in SCD patients were recorded over the period 2006 to 2011. Conventional transfusions and ECP were compared. RESULTS: The cohort consisted of 188 SCD patients. The median (±SD) age was 23 (±14) years. The ECP and conventional transfusion groups comprised 49 and 139 patients, respectively. The prevalence of alloimmunization was 33% in the ECP group and 22% in the conventional transfusion group (p = 0.1797). The alloimmunization/RBC unit (RBCU) ratio was lower in the ECP group than in the conventional transfusion group (1.6 and 11.6 per 1000, respectively; p < 0.0001). Although patients in the ECP group received more than 10 times more RBCUs than patients in the conventional transfusion group (206 vs. 19 RBCUs per patient, respectively; p < 0.0001), none of the four recorded hemolytic transfusion reactions (n = 4) occurred. CONCLUSION: Regarding alloimmunization, ECP exhibits a good immunohematologic safety profile relative to conventional transfusion in a large SCD mainly adult cohort.