IMMUNOLOCALIZATION OF AROMATASE IN HUMAN MINOR SALIVARY-GLANDS OF THELOWER LIP WITH PRIMARY SJOGRENS-SYNDROME

The enzyme aromatase is involved in the conversion of androgens to est rogens and in the modulation of various androgenic and estrogenic acti ons. Abnormalities of estrogen metabolism have been postulated to play roles in the development and/or pathophysiology of Sjogren's syndrome . In the present study, aromatase was immunolocalized in 75 cases of i nflammatory disorders of human minor salivary glands of the lower lip. These included cases of primary Sjogren's syndrome (19 cases), of chr onic sialadenitis (34 cases) and of mucous extravasation cysts (22 cas es), in order to clarify the possible involvement of in situ estrogen production in primary Sjogren's syndrome. Aromatase immunoreactivity w as detected in myoepithelial cells of acini and in interstitial cells adjacent to acini and ducts in 13/19 (68%) cases of primary Sjogren's syndrome. In contrast, aromatase expression was detected in only six o f 34 (18%) cases of chronic sialadenitis and in seven of 22 (32%) case s of mucous extravasation cyst. These results suggest that increased a romatase expression in minor salivary glands with primary Sjogren's sy ndrome in premenopausal women may be involved in the biological featur es of primary Sjogren's syndrome through the production of estrogens i n situ and possibly through the aggravation of the inflammatory reacti on.