Increased frequency of Sjögren's syndrome in patients with spondyloarthropathy

To determine the prevalence of sicca symptoms and Sjögren's syndrome (SS) in spondyloarthropathy (SpA) patients with ankylosing spondylitis (AS) and undifferentiated SpA (uSpA).

Patients with SpA with inflammatory back pain and/or peripheral arthritis presenting to the university outpatient clinic were diagnosed as AS (n = 40) and uSpA (n = 65) according to established criteria. Patients with SpA with sicca symptoms and/or positive antinuclear antibody (ANA) were investigated for SS by minor salivary gland biopsy and/or sialography. To assess sicca symptoms in this cohort systematically we mailed a validated questionnaire with 6 questions on dryness of eyes and mouth to all 105 SpA patients and 150 healthy controls, a positive answer to > or = 3 questions was taken as suggestive of SS. There was no significant difference in baseline characteristics between patients and controls.

In 8/105 SpA patients (5 uSpA, 3 AS; 6 female, 2 male) SS diagnosis by the European criteria indicated a frequency of 7.6%. Of 105 SpA patients, 12 were ANA+ (11.4%), of whom 7 had SS; thus, ANA were detected in 7/8 SpA patients with SS (88%). Of the 84 SpA patients responding to the questionnaire (80%), 10 gave a positive answer to > or = 3 questions (11.9%) compared to 2 of 131 (1.5%) controls (87.3%) (odds ratio = 8.7, 95% CI 2.3-32.5, p < 0.01).

The data suggest increased prevalence of sicca symptoms and SS in SpA patients with AS and uSpA. The occurrence of a secondary SS in a variety of inflammatory diseases suggests that salivary gland involvement in these conditions results from as yet unidentified shared pathogenic mechanisms resulting in nonspecific inflammation in this location.