Immunohistopathology of Sjögrenʹs syndrome

Sjögrenʹs syndrome (SS) is characterized by keratoconjunctivitis sicca and xerostomia, which occur in an autoimmune lacrimal and salivary gland disease characterized by lymphocyte infiltrates of exocrine glands and/or Sjögrenʹs syndrome autoantibody production. It has been reported that aquaporin-5 distribution is abnormal in SS, perhaps as a result of paracrine effect of TNF-α. Also the neurogenic regulation of the salivary gland is impaired in SS. Apart from functional changes, the syndrome is also characterized by structural abnormalities of the secretory acinar apparatus. The acinar basement membrane is abnormal as it lacks laminin α1 chain, which may impair its capability to induce the progenitor cells to differentiate to acinar cells. CRISP-3 and TMPRSS-2 can be used as androgen markers and LIV-1 and Cyr61 as estrogen markers to study the sexual dimorphism of the salivary glands. Patients with SS seem to have low concentrations of dehydroepiandrosterone, which may predispose women and the exocrine glands to this syndrome.