Clinical evolution, and morbidity and mortality of primary Sjogren's syndrome

Objectives: To study the clinical and laboratory profile evolution, as well as morbidity and mortality impact, of primary Sjogren's syndrome (pSS), in a large cohort of patients followed-up longitudinally. Methods: We studied the evolution of the clinical picture and laboratory pr ofile of pSS, the incidence and predictors for systemic sequelae, and the i mpact of pSS on overall survival in a prospective cohort study of 261 patie nts with pSS. Analyses included calculation of incidence rates, Cox proport ional hazards predictive models, and estimation of standardized mortality r atios (SMRs) compared with the general Greek population, adjusting for age and sex. Results: Glandular manifestations of the syndrome were typically present at the time of diagnosis. Systemic manifestations such as arthritis, Raynaud' s phenomenon, purpura, interstitial nephritis, and liver involvement, as we ll as the serological profile, also did not change substantially during sub sequent follow-up. Incidence rates for peripheral neuropathy, glomeruloneph ritis, and lymphoproliferative disorders were 3.3, 6.6, and 12.2 per 1,000 person-years, respectively. Glomerulonephritis and lymphoma tended to co-ex ist in the same patients (relative risk, 34.0; P<.0001). The development of lymphoproliferative disorders was associated with low levels of C4 complem ent (relative risk, 7.5; P=.0016), the presence of mixed monoclonal cryoglo bulins (relative risk, 7.9; P=.0012), and purpura (relative risk, 3.9; P=.0 37). Low levels of C4 was the strongest predictor for mortality after adjus ting for age (relative risk, 6.5; P=.0041). Patients with pSS had an SMR of 2.07 (95% CI, 1.03 to 3.71). However, when patients with adverse predictor s were excluded, the mortality rate was identical to that of the general po pulation (SMR 1.02). Conclusions: The initial presentation of pSS determines subsequent outcome. Purpura, decreased C4 complement levels, and mixed monoclonal cryoglobulin emia are adverse prognostic factors. The overall mortality of patients with pSS compared with the general population is increased only in patients wit h adverse predictors. Copyright (C) 2000 by W.B. Saunders Company.