Micafungin-induced hemolytic anemia: a case report and investigation of anti-micafungin antibody prevalence.

Micafungin and other echinocandins are commonly used for the prophylaxis and empirical treatment of invasive fungal infections in neutropenic patients due to their broad-spectrum activity and favorable safety profile. Drug-induced hemolytic anemia (DIHA) is a rare condition, and micafungin-related cases are exceptionally uncommon. We describe a fatal case of intravascular hemolysis triggered by re-administration of micafungin in a patient receiving chemotherapy for peripheral T cell lymphoma. The patient experienced convulsions and shock within minutes of infusion of the drug, followed by severe hemolysis and disseminated intravascular coagulation. Subsequently, hemolytic mechanisms were evaluated using drug-adsorption and immune complex models. Additionally, we had sera from eight patients treated with micafungin between January 2019 and December 2022, including our index case, tested for anti-micafungin antibodies. Immune complex-mediated hemolysis was confirmed in the index case, supported by positive indirect antiglobulin tests and in vitro hemolysis. Anti-micafungin antibodies were only detected in this single patient, indicating an extremely rare immunologic reaction. Although rare, micafungin-induced DIHA can be life-threatening. Clinicians should remain vigilant, particularly when resuming or continuing administration of micafungin.