Drug-induced Coombs-negative autoimmune hemolytic anemia in a patient undergoing maintenance hemodialysis

A 61-year-old man with chronic renal failure undergoing maintenance hemodialysis was admitted for arteriovenous access thromboses. Piperacillin (PIPC) was administered after surgical fistula revision. Severe hemolysis was developed after 12 days of this surgery. Hematocrit decreased from 26.1% on admission to 13.8%. Laboratory findings were consistent with autoimmune hemolytic anemia (AIHA) except for negative direct Coombs'test. Although PIPC and other drugs were discontinued anemia did not abate. Oral prednisolone was initiated based on a diagnosis of Coombs-negative AIHA and five days later, the hematocrit rose to 28.4%. Using an immunoradiometric assay (IRMA), IgG on the red cells was quantitated. Eventually, we diagnosed drug-induced Coombs-negative AIHA, for which low dose prednisolone was very effective. There have not been any recurrences for 9 months while on tapered doses of prednisolone.