Immunohistological analysis of tumour growth factor β1 expression in normal and inflamed salivary glands

Aim. To determine whether transforming growth factor-β1 (TGF-β1) has a pathogenetic role in disease of the salivary glands. Methods. An indirect immunohistochemical technique was used to analyse TGF-β1 expression in six specimens of normal salivary gland and 23 surgical specimens. Results. TGF-β1 was strongly expressed in the ductal epithelial cells of normal salivary gland tissues (six of six cases) and in inflammatory conditions (eight of 11 cases). In contrast, TGF-β1 was not detectable in ductal epithelial cells expressing HLA-DR around infiltrating CD4+ CD45RO+ activated T cells, in the salivary gland tissue of patients with Sjogren's syndrome, Conclusion. Because TGF-β1 has an essential role in the mucosal immunity of salivary glands, abnormal expression of this cytokine must be regarded as a candidate in the pathogenesis of Sjogren's syndrome.