Prevalence of secondary Sjögren's syndrome in Indian patients with rheumatoid arthritis: a single-center study

To assess the prevalence of secondary Sjögren's syndrome (sSS) and its association with joint damage in patients with rheumatoid arthritis (RA) from northern India.

Patients included had RA, fulfilling the 1987 American College of Rheumatology criteria, with disease duration of more than 1 year. They were administered a sicca questionnaire that included six questions from subjective criteria of American European Consensus Group (AECG) criteria. Those who answered affirmatively to at least one question underwent Schirmer I test (ocular function) and salivary scintigraphy (salivary gland involvement). Patients with involvement of both were classified as having sSS as per AECG criteria. A damaged joint count was done using Norfolk Arthritis Register Damaged Joint Count (NOAR-DJC).

This study included 199 patients with RA, with mean (SD) age and disease duration of 44 (9.9) and 6.8 (5.5) years, respectively. The prevalence of sicca symptoms and sSS was 14.6% and 5.5%, respectively. Those having sSS had a longer (mean ± SD) disease duration (9.2 ± 4.0, 6.8 ± 5.5 years, P = 0.07) and were significantly older in age (50.8 ± 6.8, 43.6 ± 9.9 years, P = 0.005) than those without sSS. There was no significant difference in the median (interquartile range) damaged joint count (0 (0-2), 0 (0-2), P = 0.75).

The prevalence of sSS in northern Indian RA patients was 5.5%, and it was significantly associated with older age but not damaged joint count.