Immunohistochemical detection of insulin-like growth factor-I in the labial salivary glands of patients with Sjögren's syndrome.

OBJECTIVE: The purpose of the present study was to investigate the presence of insulin-like growth factor-I (IGF-I) in the labial salivary glands of patients with Sjögren's syndrome and healthy controls and to determine if there are any differences between these two groups.

DESIGN: An immunohistochemical study.

SUBJECTS AND METHODS: Twenty-five patients with Sjögren's syndrome, 20 healthy controls and 20 patients with mucoceles of the lip were used in this study. All individuals underwent a systemic evaluation and a lip biopsy. Sections from the lip biopsies were stained with haematoxylin and eosin (H&E). Immunohistochemical staining was also performed using a three-step indirect immunoperoxidase for IGF-I.

RESULTS: The light microscopic examination revealed the presence of a mononuclear infiltration in the labial salivary glands of patients with Sjögren's syndrome. Most of the infiltrates were lymphocytes. Immunohistochemically an intense staining result was apparent in the same group. In contrast sections of labial salivary glands of healthy individuals and of patients with mucoceles revealed very weak staining.

CONCLUSIONS: The above findings and the fact that both lymphocytic infiltration and IGF-I were predominantly seen in ductal regions, suggest that IGF-I may be a target of autoimmunity in Sjögren's syndrome.