IMMUNOHISTOCHEMISTRY OF MINOR SALIVARY-GLAND BIOPSY SPECIMENS FROM PATIENTS WITH SJOGRENS-SYNDROME WITH AND WITHOUT HEPATITIS-C VIRUS-INFECTION

Objectives-To characterise phenotypically the minor salivary glands of patients with clinical and histological features of Sjogren's syndrom e (SS) infected with hepatitis C virus (HCV). Patients and Methods-75 consecutive patients with SS (31 primary SS, 44 secondary SS) diagnose d by preliminary classification criteria. The of anti-HCV antibodies w as detected by commercial third generation ELISA and by a second gener ation immunoblot assay. Presence of HCV genome in serum was determined by polymerase chain reaction analysis. Expression of CD3, CD4, CD8, C D20, HLA-DR, and CD25 molecules in lymphocytic and epithelial cells on minor salivary glands was detected by immunohistochemical assays. Exp ression of interferon gamma and interleukin 4 cytokines was determined by in situ hybridisation. Results-Six of 31 primary SS (19%) and one of 44 secondary SS (2%) serum samples were positive for anti-HCV by EL ISA. Three samples were positive, three indeterminate, and one sample corresponding to a secondary SS patient was negative by immunoblot. Th e three immunoblot positive serum samples were also HCV-RNA positive b y PCR assay. The study of lymphocytic cells in the diffuse infiltrate of minor salivary glands showed a predominance of the CD3 lymphocytic population. A predominance of CD4 over CD8 T cells (ratio 2:1) was obs erved in HCV and non- HCV infected patients. The analysis of the lymph ocytic focus showed that the HCV infected patients had a predominance of CD20 positive cells. Activation molecules ( CD-25 and HLA-DR) were expressed in HCV and non-HCV infected patients in lymphocytic and epit helial cells, however epithelial cell expression of CD25 was low in HC V infected patients. As expected, a pronounced Th1 response was observ ed in the lymphocytic foci of HCV patients. Conclusions-HCV infected p atients may develop an autoimmune sialadenitis, similar to that descri bed in primary SS.