| Abstract: | A patient was found to have a positive direct antiglobulin test and thrombocytopenia while on a moderate dose of intravenous penicillin. Serological evaluation of the patient's red cells demonstrated that the positive antiglobulin test was due to antipenicillin antibody. This antibody also was demonstrated in the patient's serum. The patient's platelets had increased quantities of IgG; an eluate from her platelets gave positive test results with platelets treated with penicillin but not normal platelets. Her serum also reacted only with penicillin- treated platelets. Multiple absorptions of her serum with red cells treated with penicillin reduced reactivity against both fresh red cells and platelets treated with penicillin. This patient demonstrated the coexistence of drug-induced immune phenomena directed against both red cells and platelets. |
