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AT-A-GLANCE
A chronic, multisystem autoimmune disease, characterized by chronic inflammation involving the exocrine glands.
Salivary and lachrymal glands are affected predominantly, leading to dry mouth and dry eyes.
May occur alone (primary Sjögren syndrome, pSS), or may coexist with other systemic connective tissue disorders (secondary Sjögren syndrome).
Extraglandular manifestations of primary Sjögren syndrome include fatigue, Raynaud phenomenon, purpura, arthritis, vasculitis, interstitial pulmonary disease, peripheral or central neuropathy, and autonomic nervous dysfunction.
Patients with systemic manifestations are at higher risk of developing lymphoma.
Treatment of sicca symptoms is mainly symptomatic, whereas management of extraglandular manifestations is similar to that of other autoimmune diseases.
Both innate and adaptive immunity contribute to pSS pathogenesis and pSS is associated with upregulation of the Type 1 interferon signaling pathway.
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Sjögren syndrome (SS) is a chronic systemic autoimmune disorder characterized by lymphocytic infiltration and destruction of exocrine glands and epithelia leading to dry mouth, dry eyes, and B lymphocyte hyperreactivity. SS can occur as an isolated disorder; primary Sjögren syndrome (pSS); it also may occur in association with other autoimmune condition such as rheumatoid arthritis, systemic lupus erythematosus (SLE) and other collagen disease; secondary SS. Disease may be localized to the salivary and lachrymal glands, but more than one-third of patients develop systemic manifestations. The clinical presentation can vary from mild sicca symptoms, fatigue, and arthralgias to severe systemic symptoms involving multiple organ systems. A small but definitely number of patients of the pSS develop lymphoma with higher incidence than that of the general population or patients with other autoimmune diseases (Fig. 68-1).
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SS is one of the most common rheumatic autoimmune diseases. SS predominantly affects women, with a female to male ratio of 9:1. Patients are most commonly diagnosed in their fourth and fifth decades of life, but it can affect any age, including the elderly and children. SS has a worldwide distribution. The estimated annual incidence rate of pSS ranged from 3.9 to 5.3 per 100,000 in several studies.1 The prevalence rates can vary considerably, depending on the classification criteria used. The estimated prevalence rate in the adult general population from previous studies, mainly in whites, was between 0.2% and 2.7%, whereas the estimated prevalence rate from Asian studies was 0.03% to 0.77%.2,3
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ETIOLOGY AND PATHOGENESIS
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Although the precise pathogenesis of SS remains largely unknown, genetic and epigenetic disposition, various environmental factors, including viral and other pathogenic infections, and hormones have been implicated in the pathogenesis of the disease. Recent studies have shown that both innate and adaptive immunity contribute to the development of pSS; the Type 1 interferon (IFN) signaling pathway plays a central role in the pathogenesis of the disease. ...