1. ¹Department of Pathology, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
2. ²Department of Dermatology, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
3. ³Department of Dermatology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain

Correspondence: María-Teresa Fernández-Figueras, Department of Pathology, Hospital Universitari Germans Trias i Pujol, Ctra. del Canyet, s/n, 08916 Badalona, Spain.

Accepted 27 September 1999.

Abstract

Expression of Bcl-2, Bcl-x, and Mcl-1 was immunohistochemically evaluated in 33 cases of Kaposi's sarcoma (KS) of the skin. Of these, classic KS (C-KS) accounted for 17 cases (10 in plaque stage and 7 in tumor stage) and acquired immunodeficiency syndrome–associated KS (AIDS-KS) accounted for 16 cases (8 in plaque stage and 8 in tumor stage). In both C-KS and AIDS-KS, Bcl-2 immunoreaction correlated with progression stage, its average score intensity being more than 2-fold in tumors than in plaques. In contrast, Bcl-x and Mcl-1 staining intensity was unrelated to progression stage but was dependent on human immunodeficiency virus infection status. Thus, whereas Bcl-x expression was stronger in C-KS cases, Mcl-1 immunostaining was more intense in AIDS-KS instances. These findings indicate that in cutaneous KS, some Bcl-2 family proteins exhibit differential expressions that are dependent on either progression stage or human immunodeficiency virus infection status.