Detection of human herpesvirus 8 and human T-cell lymphotropic virus type 1 sequences in Kaposi sarcoma

Background: Ultrastructural studies have shown retroviral particles in Kaposi sarcoma (KS) unrelated to infection with the human immunodeficiency virus (HIV). Recently, DNA sequences from a new herpesvirus, human herpesvirus 8 (HHV-8), were detected in KS tissues. Objectives: To screen for the presence of HHV-8 sequences in patients with KS not related to HIV infection and correlate HHV-8 sequence detection and clinical staging and to screen for the presence of human T-cell lymphotropic virus type 1 (HTLV-1) sequences in the peripheral blood mononuclear cells (PBMCs) of such patients. Design: Tumor and normal skin samples and PBMCs were investigated by polymerase chain reaction using primers for HHV-8 and HTLV-1 pX gag, pol, and env sequences. Setting: Ambulatory or hospitalized patients from a university hospital associated with a research laboratory. Patients: Thirty-one patients with KS not related to HIV infection (21 classic cases, 3 endemic cases, 1 case associated with Castleman disease, 4 homosexual men, 1 posttransplantation patient, and 1 patient taking corticosteroids). Stages involved included I (13 patients), II (8 patients), III (7 patients), and IV (3 patients). Results: Human herpesvirus 8 sequences were found in 100% of KS specimens, 70% of distant normal skin specimens, and 42% of PBMC samples. The percentage of HHV-8 detection in PBMCs was higher in patients with KS stage III or IV than in patients with stage I or II. Human T-cell lymphotropic virus type I pX sequences were detected in 2 of 19 patients while gag, pol, and env-test results were negative using polymerase chain reaction analysis. Conclusions: Our data suggest no significant association between HTLV-1 infection and KS. Detection of HHV-8 infected cells in normal skin samples from the majority of KS tissues, regardless of clinical staging, can be paralleled to the multifocal pattern of the disease. Human herpesvirus 8 detection in PBMCs could be related to the tumor burden.