Rifabutin-Induced Thrombocytopenia in a Patient With Uncontrolled HIV: A Case Report.

Uncontrolled HIV is associated with a wide range of hematologic abnormalities through direct suppressive effects, opportunistic infections, tumor marrow infiltration, or antiretroviral, antimicrobial, or antitumor therapy. We present a patient with a history of uncontrolled HIV presenting with acute severe thrombocytopenia shortly after starting treatment for disseminated Mycobacterium avium complex (MAC). While the thrombocytopenia was resistant to transfusion and intravenous immunoglobulin (IVIG), it mildly improved with dexamethasone after holding home medications. Etiologies for this patient's thrombocytopenia include uncontrolled HIV infection and medication-induced, likely secondary to rifabutin. We propose a possible combined effect of both factors. Clinicians should be aware of the increased risk of severe, acute medication-induced thrombocytopenia in patients with uncontrolled HIV, given their baseline susceptibility to hematologic abnormalities.