Triggering of suicidal erythrocyte death by amphotericin B

Amphotericin B is widely used as antifungal drug. Side effects include anemia. A variety of drugs and diseases associated with anemia has recently been shown to trigger suicidal erythrocyte death or eryptosis, i.e. cell membrane scrambling and cell shrinkage. Eryptosis may be triggered by increased cytosolic Ca2+ activity and by lack of ATP. The present study explored whether amphotericin B stimulates eryptosis. Cell membrane scrambling was estimated from annexin V-binding to phosphatidylserine exposed at the cell surface, cell shrinkage from forward scatter in FACS analysis, cytosolic Ca2+ activity from Fluo3 fluorescence and the cytosolic ATP concentration from a luciferase-based assay. Exposure to amphotericin B (0.1-1 microg/ml) within 48 hours significantly increased annexin V-binding, decreased forward scatter, increased cytosolic Ca2+ activity and decreased cytosolic ATP content. In conclusion, amphotericin B stimulates suicidal cell death of erythrocytes, which may in turn contribute to the clearance of circulating erythrocytes and thus to anemia.