Response of severe HIV-associated thrombocytopenia to highly active antiretroviral therapy including protease inhibitors

Objective: To investigate the response of HIV-associated severe thrombocyto penia (STP) to highly active antiretroviral therapy (HAART) including prote ase-inhibitors. Methods: In this retrospective study, IS patients with HIV-associated STP ( platelet count < 50 x 10(9)/l), mostly antiretroviral experienced (13/15), underwent HAART for at least 6 months (median 21; range 6-41 months) during which the platelet (PIT) count and plasmatic HIV-RNA were monitored. The P LT response was compared to that observed in 19 patients previously treated with zidovudine (AZT) monotherapy. Results: HAART induced a significant increase in the PLT count (chi (2) = 1 0.53, P = 0.01) within the third month which was sustained up to the sixth month of therapy. No STP relapse was observed among eight PLT responders fo llowed for longer than 6 months (median 27; range 7-41 months). The PLT inc rease after HAART was similar to that observed with AZT monotherapy, but a greater number of HAART patients were antiretroviral-experienced. HAART det ermined a PIT response in 10/13 subjects whose thrombocytopenia had not imp roved after previous AZT monotherapy. After 6 months of HAART, a complete p latelet response occurred more frequently in patients with undetectable pla sma HIV-RNA levels (P = 0.01). Conclusions: HAART induces a sustained PLT response in HIV-associated STP, even in antiretroviral-experienced subjects and in those with AZT-resistant thrombocytopenia. An undetectable plasma HIV viraemia induced by HAART is necessary for STP recovery. (C) 2001 The British Infection Society.