Serologic characteristics of ceftriaxone antibodies in 25 patients with drug-induced immune hemolytic anemia.

BACKGROUND: Ceftriaxone, a third-generation cephalosporin, is commonly used to prevent and treat infections. Since 1987, it has been the second most common cause of drug-induced immune hemolytic anemia (DIIHA) investigated in our laboratory. STUDY DESIGN AND METHODS: Samples from 79 patients (1987-2010), suspected of having DIIHA caused by ceftriaxone, were studied for the presence of ceftriaxone antibodies. Direct antiglobulin tests (DATs) and tests with ceftriaxone-treated red blood cells (RBCs) or untreated and enzyme-treated RBCs in the presence of ceftriaxone were performed. RESULTS: Twenty-five (32%) of the 79 patients had antibodies to ceftriaxone detected. Seventeen (68%) of the 25 patients were children; reactions in children were usually dramatic and severe. Nine (36%) of the 25 patients had fatal DIIHA. Nineteen of the 25 samples had DATs performed by our laboratory; 100% of samples were reactive with anti-C3 and 47% were reactive with anti-IgG. All 25 sera had ceftriaxone antibodies detected when testing untreated or ficin-treated RBCs in the presence of ceftriaxone (resulting in agglutination, hemolysis or sensitization of test RBCs). These antibodies were primarily IgM and reactivity was enhanced by testing ficin-treated RBCs. Sixteen (64%) of the 25 sera reacted with test RBCs when no ceftriaxone was added in vitro; this was most likely due to the transient presence of drug or drug-immune complexes in the patient's circulation at the time that the blood samples were drawn. CONCLUSION: Ceftriaxone antibodies can cause severe intravascular hemolysis. Complement can usually be detected on the patient's RBCs and IgM antibodies are usually detected in the patient's serum.