Report on a 3-year follow-up zidovudine (AZT) treatment in a group of HIV-positive patients with congenital clotting disorders.

Eleven (50%) of 22 HIV-seropositive patients suffering from congenital coagulation defects and followed at the Hemophilia Center of Padua met the eligibility criteria for zidovudine (AZT) therapy. A 3-year clinical and laboratory follow up is described. Mean length of AZT treatment was 14.3 +/- 11 months. Three patients were enrolled at the latest stages (CDC stage IV) of HIV disease. They showed no clinical improvement after AZT administration and died with AIDS. One CDC stage III patient died from a high-grade non-Hodgkin's lymphoma (NHL) which suddenly developed 3 months after starting AZT. Seven patients began antiretroviral treatment when they were mild or asymptomatic for HIV infection (CDC stage II and III). None developed any sign of HIV disease progression on the basis of CDC criteria. Moreover, AZT administration induced an improvement of the humoral markers related to HIV disease, as CD4 T-lymphocyte count, serum beta 2-microglobulin (B2M) and, although only for few months, neopterin (Np) levels. A mild thrombocytopenia due to HIV infection was detected in 5 patients. In all cases AZT treatment was effective in increasing and/or normalizing the platelet count. Reduced daily dose AZT (600-500 mg/day) appeared to be well tolerated and of minimal toxicity as compared to the higher dose (1200 mg/day). In our study, the zidovudine-induced bone marrow suppression, namely severe anemia or pancytopenia, was the major side-effect limiting tolerance of the higher dose AZT.