Initial observations on the efficacy of highly active antiretroviral therapy in the treatment of HIV-associated autoimmune thrombocytopenia.

BACKGROUND

Immune thrombocytopenic purpura (ITP) occurs in as many as 40% of patients infected with the human immunodeficiency virus (HIV). We sought to evaluate the effect of highly active antiretroviral therapy (HAART) on platelet counts in such patients.

METHODS

Data collected from 11 homosexual men with HIV-associated ITP and < or = 50 x 10(9) platelets were analyzed after they were placed on HAART. At initial evaluation, 7 patients were antiretroviral naive, 2 were taking zidovudine alone, and 2 were receiving combination antiretroviral therapy for known HIV infection. For 6 patients with <30 x 10(9) platelets, prednisone was initially coadministered with HAART. The primary outcome measure was the platelet count response to HAART, which was measured weekly until counts had normalized on 3 consecutive occasions, then every 3 months while on HAART. Secondary outcome measures were HIV-viral RNA levels and CD4+ cell counts.

RESULTS

One month after the initiation of HAART, 10 evaluable patients had an increase in mean platelet count. This improvement was sustained at 6 and 12 months' follow-up for 9 of 10 evaluable patients. Increases in mean platelet count at 6 and 12 months of the 9 responders were statistically significant. The range of follow-up in the 9 responders is 21 to 46 months (median, 30 months), with no thrombocytopenic relapses. The 9 long-term platelet responders have been maintained on HAART and at 12 months had a mean reduction of > 1.5 log10 in HIV viral RNA serum levels and a marked improvement in CD4+ T-lymphocyte cell count.

CONCLUSION

HAART seems to be effective in improving platelet counts in the setting of HIV-associated ITP, enhancing CD4+ cell counts, and reducing HIV viral loads.