Human immunodeficiency virus associated with thrombotic thrombocytopenic purpura: successful treatment with zidovudine. Thrombocytopenia associated with human immunodeficiency virus (HIV) is well described, and two recent reports show a beneficial effect with the antiretroviral agent zidovudine (ZDV). HIV-associated thrombotic thrombocytopenic purpura (TTP) has recently been observed, but the use of ZDV for it has not been previously described. We have reported a case of relapsing TTP in an HIV-positive man who achieved remission with plasmapheresis and antiplatelet therapy initially, but multiple relapses necessitated the addition of vincristine and ZDV to induce a sustained remission. 