Objective: To describe the effect of HAART on Kaposi sarcoma herpes virus (KSHV) antibody response and viremia among HIV-positive MSM.
Design: A follow-up study of 272 HIV-positive MSM (including 22 with Kaposi sarcoma) who first initiated HAART between January 1996 and July 2004 in the Swiss HIV Cohort Study.
Methods: For each individual, two serum samples, one at HAART initiation and another 24 months later, were tested for latent and lytic KSHV antibodies using immunofluorescence assays, and for KSHV viremia using PCR. Factors associated with changes in KSHV antibody titers and viremia were evaluated.
Results: At HAART initiation, 69.1 and 75.0% of patients were seropositive to latent and lytic KSHV antibodies, respectively. Seropositivity was associated with the presence of Kaposi sarcoma, older age, lower CD8+ cell count and higher CD4+/CD8+ ratio. Prevalence of KSHV viremia at HAART initiation was 6.4%, being significantly higher among patients with Kaposi sarcoma (35.0%), and those with HIV viral loads 100 000 copies/ml (11.7%) or higher. At 24-month follow-up, geometric mean titers (GMTs) among KSHV seropositive patients increased and antibody seroprevalence was higher. Having Kaposi sarcoma and/or CD4+ cell counts less than 50 cells/μl at HAART initiation was associated both with higher probability for antibody titers to increase (including seroconversion) and larger increases in GMTs. Only one of 17 viremic patients at HAART initiation had viremia at 24-month follow-up.
Conclusion: HAART increases KSHV-specific humoral immune response and clearance of viremia among HIV-infected MSM, consistent with the dramatic protection offered by HAART against Kaposi sarcoma.
aInternational Agency for Research on Cancer, Lyon, France
bDepartment of Epidemiology, University of California, Los Angeles (UCLA), Los Angeles, California, USA
cInstitute for Medical Microbiology, University of Basel, Basel, Switzerland
dGeneva University Hospital, Geneva, Switzerland
eDivision of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
fInstitute for Infectious Diseases, University of Bern, Bern, Switzerland
gCoordination and Data Centre, Swiss HIV Cohort Study, Lausanne, Switzerland.
*The members of the study are listed in the Acknowledgment section.
Received 1 February, 2010
Revised 22 April, 2010
Accepted 28 April, 2010
Correspondence to Dr Gary M. Clifford, International Agency for Research on Cancer, 150 cours Albert Thomas, 69372 Lyon cedex 08, France. Tel: +33 472738425; fax: +33 472738345; e-mail: email@example.com