Pulmonary Manifestations of Sjögren's Syndrome

Sjögren's syndrome, a chronic autoimmune inflammatory disease, is one of the most common systemic rheumatic diseases, affecting 0.1% of the general population and 3% of older adults32; women are more commonly affected than men (9:1, female:male). Affected patients typically present in the fourth or fifth decade of life, the common presenting symptoms being the classic triad of: dry mouth (xerostomia), dry eyes (keratoconjunctivitis sicca or xerophthalmia), and arthritis.72 Heinrich Sjögren, whose name the syndrome bears, was not the first to describe this condition, but he recognized that the disease was a systemic disorder and described the pathology of the xerophthalmia, thereby introducing the term keratoconjunctivitis sicca. Sjögren's syndrome is now known to be an autoimmune exocrinopathy67 and autoimmune epithelitis.50 The syndrome is characterized pathologically by lymphoproliferation and lymphocyte infiltration of glandular and nonglandular tissue. In most patients, lymphocyte infiltration is confined to the salivary and lacrimal glands, but extraglandular infiltration occurs in 5% to 10% of affected patients.72 Lymphocyte infiltration has been identified in the lungs, pancreas, gastrointestinal tract, hepatobiliary system, kidneys, skin, and bone marrow.44 Lymphoproliferation in Sjögren's syndrome is usually benign, but malignant transformation occurs in some cases. Typically, the cellular infiltrate is predominantly CD4-positive T cells1 and also may contain B lymphocytes, plasma cells, and large reticulum cells.72 The lymphocytes may form nonmalignant, tumor-like aggregates, a condition termed pseudolymphoma. If the infiltrative process is frankly malignant it is typically a non-Hodgkin's lymphoma or less frequently Waldenström's macroglobulinemia. Sjögren's-associated lymphoma may arise years after the diagnosis of Sjögren's syndrome. Therefore, a pathologic diagnosis of the cellular infiltrate should be obtained at the time of disease onset and if there is evidence of disease progression.