Objectives The aim of this study was to evaluate into a cohort of patients assessed for sicca syndrome the prevalence of secondary Syogren's syndrome (sSS) in patients affected by spondyloarthritis (SpA), considering SpA a possible cause of sSS.
Methods We evaluated,from December 2009 to December 2014 a total of 221 consecutive patients affected by sicca syndrome for suspected Sjogren's syndrome (SS), 208 females and 13 males aged between 23 and 89 years(mean age 50.94 years). Each patient underwent minor salivary glands biopsy, anti-nuclear antibodies detection, anti-Ro and anti-La antibodies detection, Schirmer test, salivary gland scintigraphy and anti-HCV serology. The acute phase reactants,the C3 and C4 complement fractions were also simultaneously evaluated and ultrasonography of both the parotid and submandibular glands was performed and assessed with the grading proposed by Salaffi et al. (range 0-4). The classification of the patients affected by primary SS (pSS) and sSS was made according to the American-European Consensus Group criteria considering SpA, arbitrarily, among the other diseases cause of sSS. The classification of the patients with SpA was made only on patients that meet the modified New York criteria or the CASPAR criteria or the Amor criteria or the ESSG criteria or the ASAS criteria for the axial or the peripheral spondyloarthritis. The statistical analysis was carried out using the Kolmogorov-Smirnov test to check the distribution, the Student's t-test for the comparison between the groups and the χ2-test to compare the categorical variables and the proportions; a p value <0.05 was considered statistically significant.
Results 141 patients were classified as affected by SS and in particular 84 with pSS and 57 with sSS; the data were inadequate in 80 patients for the definition of SS (46 patients with essential sicca syndrome and 34 with UCTD). 21 of the 57 patients with sSS were affected by spondyloarthritis (36.84%) and the SS resulted secondary to rheumatoid arthritis in 20 patients (RA; 35.08%). The two groups of patients, one with sSS and SpA and the other one with sSS and RA were not reporting substantial differences in the average age, sex and in the Schirmer test positivity (51,76±12,5 vs 47,60±15,9 years, p=0.35; 20/21 vs 18/20 females, p=0.5; 90.47 vs 90.00%, p=0.66); the anti-nuclear antibodies, the anti-Ro/anti-La antibodies, the anti-CCP antibodies and the rheumatoid factor detection (61.90 vs 90.00%, p>0.05; 14.28 vs 50.00%, p=0.016; 19.04 vs 75.00%, p=0.001; 9.52 vs 80.00%, p<0.000) in the SpA group were less frequently positive; further the finding of the histological focus score ≥1 (57.14 vs 90.00%, p=0.06) and of a more advanced grading (2-4) at the ultrasography evaluation of the parotid and submandibular glands (52.38 vs 70.00%, p=0.34) resulted less frequently in the SpA group.
Conclusions Since SpA were considered a possible cause of sSS,these patients represent in our series 9.50% of all the patients assessed for sicca syndrome, 14.89% of the patients with SS and 36.84% of the patients with sSS.Comparing sSS-SpA patients and sSS-RA patients the only statistically significant differences resulted in the lower frequency of anti-Ro/anti-La antibodies, anti-CCP antibodies and rheumatoid factor positive detection in patients with SpA.The data reported suggest the evaluation of the sicca symptoms in patients with spondyloarthritis in agreement with other studies in the literature.
Disclosure of Interest None declared