Adding contrast to shed some light-a case of acute thrombocytopenia due to iohexol-dependent antibodies to glycoprotein IIb/IIIa.

Thrombocytopenia due to iodine contrast media is a rare complication, only sporadically reported in the medical literature. The mechanism for thrombocytopenia is not known, but the platelet count dynamics in the reported cases suggest an immunological mechanism, and it is reasonable to clinically diagnose it as drug-induced immune thrombocytopenia. However, no contrast media-dependent platelet-associated antibodies have ever been detected. Herein, we describe an elderly male who experienced severe thrombocytopenia following a contrast-enhanced computed tomography. As this was the third episode of sudden onset, severe, self-limiting thrombocytopenia following radiological examinations, drug-induced immune thrombocytopenia was suspected. Through laboratory work-up, we confirmed platelet-reactive drug-dependent antibodies in the presence of iohexol. The drug-dependent antibodies showed specificity for the glycoprotein IIb/IIIa complex (gpIIb/IIIa). Thus, iohexol can cause severe drug-induced immune thrombocytopenia through an antibody-mediated mechanism, and we now have the first laboratory confirmation of iodine contrast medium-dependent platelet-reactive antibodies.