[EBER-1 expression in salivary glands of Sjögren's syndrome]

EB virus-encoded small nuclear RNAs (EBERs) which present in large numbers during persistent infection, are known to stably bind to SSB/La antigen, leading to speculation that EBV may be involved in the pathogenesis of primary Sjögren's syndrome (1 degree SjS). Although studied by many investigators serologically, immunohistochemically and molecular biologically, this remains controversial. In situ hybridization study for EBER-1 showed positive hybridization in ductal epithelial cells in nine of eighteen salivary glands (SGs). Hybridization was more intense in ducts surrounded by infiltrating mononuclear cells (MNCs). Positive hybridization was also seen in infiltrating MNCs in eight 1 degree SjS SGs. These results indicate that EBV plays some pathogenic roles in some cases of 1 degree SjS through induction of SSB/La antibody and impairment of lymphocytes.