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.