1. ¹Laboratory of Pharmacology, INSERM U716, Saint-Louis Hospital, Paris, France
2. ²Department of Dermatology, Saint-Louis Hospital, Paris, France
3. ³Laboratory of Immunology and Histocompatibility, Saint-Louis Hospital, Paris, France
4. ⁴Laboratory of Pathology, Saint-Louis Hospital, Paris, France
5. ⁵Department of Internal Medicine, Saint-Louis Hospital, Paris, France
6. ⁶INSERM U553, Hôpital Saint-Louis, Paris, France
7. ⁷INSERM U429, Hôpital Necker, Paris, France

Correspondence: Professor Céleste Lebbé, Policlinique de Dermatologie, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75475 Paris cedex 10, France. E-mail: celeste.lebbe@sls.ap-hop-paris.fr

Received 7 June 2005; Revised 30 September 2005; Accepted 21 October 2005; Published online 12 January 2006.

Abstract

In order to gain further insight on the role of Kaposi's sarcoma-associated herpesvirus (KSHV) in classic and endemic Kaposi's sarcoma (KS) pathogenesis, we aimed to determine (i) whether KSHV is detectable in peripheral blood mononuclear cells (PBMCs), (ii) which PBMCs subpopulation harbor the virus, (iii) which clinical, histologic, and immunologic parameters are associated with KSHV viremia in a population of classic and endemic KS. KSHV viremia and various immunologic parameters were screened on 81 patients. KSHV viremia was positive in 58% of the patients. KSHV was detected in B cells, T cells, and monocytes. CD34+ cells depleted in circulating endothelial cells (CECs) were never infected and 50% of the patients tested had CECs infected by KSHV. We observed a significant increase of IL-2 and IFN- production by CD4 T cells and an increase of IFN- production by CD8 T cells compared to control patients. KS progression (P=0.001) and KS staging (P=0.03) were significantly and independently associated with positive KSHV viremia. Our results show that there is no specific immunosuppression in classic or endemic KS. We showed that KSHV can be detected within CECs and that KSHV viremia could be an indicator of circulating mature or precursor spindle cells.