Cross-reactivity between piperacillin-tazobactam and cefoperazone-sulbactam in drug-induced immune thrombocytopenia

Beta-lactam antibiotics commonly cause immune thrombocytopenia. Cross-reactivity in patients with drug-induced immune thrombocytopenia has rarely been reported. In this study, we describe the case of a 79-year-old man who developed thrombocytopenia after receiving piperacillin-tazobactam for an acute exacerbation of chronic obstructive pulmonary disease, and he was successfully treated with meropenem and cefotiam. However, thrombocytopenia recurred after cefoperazone-sulbactam administration. This indicated that cross-reactivity of platelet-specific antibodies occurred between piperacillin-tazobactam and cefoperazone-sulbactam. However, the responsible drug structures remain unknown, requiring further investigation. Likewise, chemical structure similarities among beta-lactam antibiotics must be examined to determine the risk of immune thrombocytopenia in the clinical setting.