Contributor: Gordon K. Klintworth
Sjögren syndrome (sicca syndrome, Gougert-Sjögren syndrome) is a slowly progressive autoimmune disease that primarily affects exocrine glands, such as the salivary gland and lacrimal gland. Occasionally the thyroid gland, lung, and kidney are also involved. The disease occurs in all ages and both genders, but is most common in women aged 40-60 years. The clinical triad consists of keratoconjunctivitis sicca, xerostomia, and a connective tissue disease (most commonly rheumatoid arthritis), but the syndrome may occur in isolation (40%). The disorder is characterized by an intense lymphocytic infiltration of the lacrimal glands (autoimmune dacryadenitis) and salivary glands. There is an infiltration of activated T-cells and B-cells and tissue destruction of the involved salivary and lacrimal glands. In lacrimal glands with Sjögren syndrome and graft-versus-host disease CD4+ cells predominate (in the normal lacrimal gland CD8+ cells are more abundant than CD4+ cells). The lymphoid tissue often forms germinal centers. In addition to the lymphocytic infiltration, ductal epithelial hyperplasia occurs and there is a luminal destruction of the lacrimal glands and salivary glands. This progresses to atrophy, destruction, and fatty replacement of the glands. Other features include hypergammaglobulinemia and the presence of autoantibodies (particularly autoantibodies directed against intranuclear DNA, histones or non-histone proteins). Sjögren syndrome is accompanied by lacrimal insufficiency with decreased lacrimal fluid secretion and is one of the causes of dry eye syndrome. Decreased tear production results in red, burning, itching eyes and photophobia. Thick strands of mucus can be seen at the inner canthus. Insufficient lacrimal secretions causes the conjunctiva and cornea to become extremely dry. A destruction of Meibomian glands results in diminished tear lipid and increased tear evaporation. The cornea develops keratitis sicca and there may be corneal inflammation, erosion, and ulceration. Sjögren syndrome can be divided into primary Sjögren syndrome [Sjögren syndrome - primary] and secondary Sjögren syndrome [Sjögren syndrome - secondary]. Patients with Sjögren syndrome have a 40-fold increased risk of malignant lymphoma. Affected individuals commonly develop a pseudolymphoma [lymphoid hyperplasia] (>5%) or B-cell lymphoma [lymphoma- B-cell] (~5%). Individuals with Sjögren syndrome sometimes develop chronic thyroiditis [thyroiditis - chronic].