Misdiagnosis in patients with diclofenac-induced hemolysis: new cases and a concise review.

Diclofenac has been implicated in many cases of life-threatening immune hemolytic anemia (IHA). Nevertheless, confusion still occurs at the bedside and in the laboratory. Herein we report nine new patients and summarize all published cases (total, n = 61). Direct and indirect antiglobulin tests were performed according to standard procedures. Tests for drug-dependent antibodies were performed in the presence and absence of the target drugs and their ex vivo antigens (in the urine of patients treated with the drug). Diclofenac- and/or ex-vivo-antigen-dependent red cell antibodies were detected in all new cases. We identified nine new cases with diclofenac-dependent IHA. All cases were initially suspected to have an abdominal illness and/or autoimmune hemolytic anemia of warm type. Acute renal failure was present in three of the 9 new patients and in 20 of 37 published patients. Seven of the 46 patients died (15%), and clinical information is lacking in 15 other published cases. Diclofenac-dependent and/or ex-vivo-antigen-dependent IHA should always be considered when a patient on diclofenac develops acute renal failure and/or IHA. 2006 Wiley-Liss, Inc.