To investigate the role of herpes viruses in Sjogren's syndrome, minor (labial) salivary gland tissues from Sjogren's syndrome and from non-specific sialadenitis were examined for Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) DNA by the polymerase chain reaction. Almost half of all salivary glands studied contained EBV and/or HCMV. There was, however, no significant difference between the detection of EBV or HCMV in salivary glands from patients with Sjogren's syndrome or non-specific sialadenitis. The findings are consistent with the persistence of EBV and HCMV in minor salivary glands following primary infection, but do not indicate a direct role for either virus in the aetiology of Sjogren's syndrome, and do not exclude reactivation of the viruses in this disease. [ABSTRACT FROM AUTHOR]