588   A Prospective Study of the Effects of Antiretroviral Therapy on Kaposi's Sarcoma andHuman Herpesvirus 8.

J. Wilkinson*¹, A. Cope², D. Bourmpoulia², J. Gill¹, N. Imami¹, R. Weiss², B. Gazzard¹, C. Boshoff², and F. Gotch¹.¹Imperial Coll. Sch. of Med., Chelsea and Westminster Hosp. and²Univ. Coll. London, UK.

Background:There have been many reports of AIDS-related Kaposi's sarcoma (KS) resolving with highly active antiretroviral therapy (HAART). Human herpesvirus 8 (HHV8) is thought to be the causative agent of KS. The effects of HAART on plasma HHV8 were prospectively studied in HIV-positive subjects with and without KS.

Methods:21 subjects with AIDS-KS were assessed prior to and during treatment with HAART. Patients were staged for KS using ACTG criteria. Serial samples were taken for HHV8 serology by IFA and quantitative real-time PCR (TaqMan). 15 HIV-positive individuals without KS also had serial HHV8 serology and PCR samples taken before and during HAART.

Results:All but one of the subjects are homosexual men (mean age 36 years, range 23—64 years). 71.4% of subjects with KS were seropositive for HHV8 by IFA and 76.2% had detectable plasma HHV8 by PCR prior to initiating HAART. The median baseline CD4 cell count and HIV viral load were 81 cells/mm³and 292,634 copies/ml, respectively. In contrast, 53.3% of subjects without KS were HHV8 seropositive and 33.3% were PCR positive. In this group the median baseline CD4 cell count and HIV viral load were 135 cells/mm³and 115,439 copies/ml, respectively. Subjects were followed up for a median of 36 weeks (range 4—75 weeks). 10 of the patients with KS demonstrated either partial or complete resolution of KS with HAART alone, 7 required additional chemotherapy, 3 subjects had progression of their KS but have not received additional KS therapy and 1 subject died of pulmonary KS. Of the KS subjects with plasma HHV8 detectable by PCR, there was a 1.29-log drop in HHV8 viral load between baseline and 30 weeks of treatment with HAART. Subjects without KS who had detectable plasma HHV8 were found to have a 2-log drop in the HHV8 viral load between baseline and 30 weeks of HAART.

Conclusions:47.6% of subjects with AIDS-KS demonstrated a clinical response to HAART alone. In addition, HIV/HHV8 co-infected individuals have a fall in HHV8 viral load following HAART.