Antiglobulin-tests for detection of auto-immunohaemolytic anaemia during long-term treatment with ibuprofen

Auto-immunohaemolytic anaemia is a very unusual complication during long-term treatment with ibuprofen. In order to detect the haemolytic antibodies involved, serum and erythrocytes from 87 patients were investigated after continuous treatment with an average daily dose of 1337 mg ibuprofen for some 6-47 months. Eight patients showed a weak or medium-positive antiglobulin test result with polyspecific anti-human serum. With monospecific anti-human serum, complement C3c and/or C3d were detected on the surface of 8 patients' erythrocytes, but none had biochemical parameters indicating haemolysis. None of the 87 patients had IgG, IgM or IgA on their erythrocytes. The findings neither indicated haemolysis present nor early stages in any of the four types of drug-induced auto-immunohaemolytic anaemia. The frequency of a positive antinuclear factor test (ANF) among patients treated with ibuprofen did not differ from that of healthy subjects in the same age group. The type of haemolysis associated with ibuprofen is discussed, but available data do not permit any definite classification. It is concluded that ibuprofen is a safe drug which rarely causes haemolysis and does not seem to cause induction of ANF.