Predicting adverse outcomes in primary Sjogren's syndrome: identification of prognostic factors

Abstract

Objective. To identify features present at diagnosis that were prospectively associated with adverse outcomes in a large cohort of patients with primary Sjögren's syndrome (SS). Methods. Two hundred and sixty-six patients diagnosed with primary SS in our department between 1984 and 2002 were consecutively included and followed up. Outcomes measured were vasculitis, B-cell lymphoma and death. Cox regression analysis was used to evaluate the effect of variables at diagnosis on outcomes. Results. Twenty-five (9%) patients developed vasculitis. Multivariate analysis identified parotid scintigraphy grades III or IV (HR 3.55, P = 0.05) and C4 levels P < 0.001) as variables predicting the development of vasculitis. Nine (3%) patients developed B-cell lymphoma. Multivariate analysis identified C3 levels P = 0.016) as a predictive factor of lymphoma development. Twenty-five (9%) patients died during follow-up. Systemic involvement (HR 4.51, P = 0.022), vasculitis (HR 4.58, P = 0.042), C4 levels P = 0.027) and cryoglobulins (HR 4.58, P = 0.013) were independently associated with death. The presence of at least two of the above-mentioned predictive factors (parotid scintigraphy, vasculitis, hypocomplementaemia and cryoglobulinaemia) was associated with a lower survival in comparison with patients with no factor (log rank and Breslow tests Conclusion. The main prognostic factors for an adverse outcome identified in our cohort of patients with primary SS were vasculitis, severe involvement in parotid scintigraphy, hypocomplementaemia and/or cryoglobulins at diagnosis. Patients with at least two of these factors need a closer follow-up.