Objective: The aims of this study were to describe the clinical presentation of primary SS (pSS) in a large cohort of patients by assessing the prevalence of the patient subgroups at high risk for severe extraglandular manifestations and to explore the influence of the patients' serological profile on disease severity and on immunosuppressive drug utilization.
Methods: Cumulative demographic, clinical, serological, histological and therapeutic data of 1115 pSS patients were retrospectively evaluated. Independent serological markers for glandular and extraglandular disease manifestations were identified by logistic regression.
Results: The cohort included 1115 (1067 female, 48 male) pSS patients. Severe extraglandular manifestations were detectable in 15% of the patients and were represented by active synovitis (11%), axonal sensory-motor neuropathy (2%), severe leucocytopenia (14%), cutaneous vasculitis (6%) and non-Hodgkin's lymphoma (4.5%). We found that low C3/C4, hypergammaglobulinaemia, RF and cryoglobulinaemia were markers of severity for pSS. According to the number of serological variables, the patients were subdivided into three distinct groups: favourable (no serological markers), intermediate (one serological marker) and poor (two or more serological markers). In comparison with the other two patient groups, pSS patients presenting with two or more adverse determinants had a higher frequency of severe visceral disease complications and required more aggressive therapeutic interventions.
Conclusion: This study confirmed that the prevalence of the pSS high-risk subset for severe systemic manifestations is ∼15%. Serological markers might help in the early identification of patients who are candidates to receive more aggressive treatments.
Keywords: Sjögren’s syndrome; disease severity; epidemiology.