High seroprevalence of human herpesvirus 8 infection in patients with systemic lupus erythematosus.

AIM: Systemic lupus erythematosus (SLE) is an autoimmune disease that is associated with genetic and environmental factors and microbial infection. With respect to microbial infection, the Epstein-Barr virus (EBV) has been a widely discussed issue in recent decades. Human herpesvirus 8 (HHV-8) belongs to the same γ-herpesvirus subfamily as EBV and is closely related to it. Until now, only one paper has reported the prevalence of HHV-8 infection in SLE patients. The goal of this study was to detect the prevalence of HHV-8 infection in SLE patients to elucidate the relationship between HHV-8 and SLE.

METHODS: We assessed the seroprevalence of HHV-8 in SLE patients by immunofluorescence assay. In addition, we quantified the HHV-8 DNA in peripheral blood mononuclear cells (PBMCs) from SLE patients by real-time polymerase chain reaction (PCR).

RESULTS: The prevalence of HHV-8 antibodies in SLE and normal controls was 57.8% (26/45) and 19.2% (5/26), respectively. These data were highly significant (P = 0.001). No HHV-8 DNA was detected by real-time PCR in SLE patients' PBMCs. In addition, we analyzed the prevalence of HHV-8 infection in patients with rheumatoid arthritis and ankylosing spondylitis. There was no significant difference between the patients and normal controls.

CONCLUSION: A high seroprevalence of HHV-8 infection was found in patients with SLE. The negative DNA load and high seropositive rate indicate that most patients might have latent infection.