The epidemiology of Sjögren’s syndrome

Abstract

Sjögren’s syndrome is a chronic systemic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. It can present as an entity by itself, primary Sjögren’s syndrome (pSS), or in addition to another autoimmune disease, secondary Sjögren’s syndrome (sSS). pSS has a strong female propensity and is more prevalent in Caucasian women, with the mean age of onset usually in the 4th to 5th decade. Clinical presentation varies from mild symptoms, such as classic sicca symptoms of dry eyes and dry mouth, keratoconjunctivitis sicca, and xerostomia, to severe systemic symptoms, involving multiple organ systems. Furthermore, a range of autoantibodies can be present in Sjögren’s syndrome (anti-SSA/Ro and anti-SSB/La antibodies, rheumatoid factor, cryoglobulins, antinuclear antibodies), complicating the presentation. The heterogeneity of signs and symptoms has led to the development of multiple classification criteria. However, there is no accepted universal classification criterion for the diagnosis of Sjögren’s syndrome. There are a limited number of studies that have been published on the epidemiology of Sjögren’s syndrome, and the incidence and prevalence of the disease varies according to the classification criteria used. The data is further confounded by selection bias and misclassification bias, making it difficult for interpretation. The aim of this review is to understand the reported incidence and prevalence on pSS and sSS, the frequency of autoantibodies, and the risk of malignancy, which has been associated with pSS, taking into account the different classification criteria used.

Pregnancy and autoimmune connective tissue diseases

“…However, it can occur at any age, and indeed, a pregnancy resulting in neonatal lupus (NL, discussed below) may be the earliest indication of PSS associated with anti-Ro/La antibodies [65]. Pregnancy outcomes beyond cardiac NL have not been studied as extensively as in SLE or APS, but from small case control studies, it appears that PSS may be associated with lower mean birthweights in offspring, older maternal age, and more common delivery by Cesarean section or vacuum extraction than in the background population [66].…”

Klinefelter's syndrome (47,XXY) is in excess among men with Sjögren's syndrome

“…Additionally, SS has a female-to-male sex bias that ranges from 20:1 to 9:1 [2]. Researchers speculate the contributing factor for the observed sexual dimorphism in the pathogenesis of SS can be attributed to the obvious difference in male and female sex steroids.…”

Finite Element Model of the Knee for Investigation of Injury Mechanisms: Development and Validation

“…1). The attachment site and matedal properties of each simulated ligament (except those simulated as 3D structures) were obtained from the literattire [19,22,35,[68][69][70][71][72][73]. Eurther, 12 uniaxial truss-connector elements were used to simulate trans-knee muscles (Eig.…”