EGF AND EGF-R IMMUNOEXPRESSION IN SJOGRENS-SYNDROME SECONDARY TO RHEUMATOID-ARTHRITIS - CORRELATION WITH EBV EXPRESSION

Minor labial salivary gland biopsies from 25 patients with secondary S jogren's syndrome (SS) suffering from rheurnatoid arthritis and from 1 1 patients complaining of ocular dryness associated with rheumatoid ar thritis without proven SS, were studied for the immunohistochemical ex pression of Epidermal Growth Factor (EGF) and its receptor (EGF-r). Mi nor labial salivary glands from 11 healthy individuals were used as th e control. Furthermore, the results were correlated with data retrieve d from a previous study on EBV expression by the in situ hybridization method in the same specimens. In 16/25 cases of secondary SS the epit helial duct cells expressed both EGF and EGF-r, particularly in the ar eas of lymphoepithelial lesion and tissue destruction. Eleven of these cases expressed a positive EBV hybridization signal In contrast, only 3/11 patients with ocular dryness and 2/11 cases from the group of he althy individuals showed immunoreactivity for EGF/EGF-r. A positive EB V signal was detected in 3/11 and 1/11 of these cases, respectively. T hese results indicate that EGF and EGF-r may play a crucial role in th e evolution of the disease under the constant influence of EBV, which seems to up-regulate the expression of the EGF/EGF-r system.