Systemic lupus erythematosus with Sjögren syndrome compared to systemic lupus erythematosus alone: a meta-analysis

This study aimed to compare the difference of the clinical and laboratory features of the patients between the combined systemic lupus erythematosus (SLE) and Sjögren syndrome (SLE-SS) and SLE only.

A systematic literature search was performed to identify the articles as to SLE with SS between 1970 and May 2011. The demographics, pertinent clinical, and laboratory data were extracted from 6 publications, and a meta-analysis was performed. The pooled odds ratios and 95% confidence interval were computed for the variability of these parameters between SLE-SS and SLE.

A total of 6 studies were included, consisting of 2489 patients with SLE and 444 with SLE-SS, and the estimated prevalence of the latter was 17.8%. Patients with SLE-SS were older and more often had associated oral ulcers and arthritis. In contrast, proteinuria (odds ratio = 1.77; 95% confidence interval, 1.39-2.25; P < 0.0001) was more common in SLE alone than SLE-SS, and central nervous system involvement tended to be more common. Anti-double-stranded DNA antibodies were equally prevalent in both groups. Anti-SSA/Ro and anti-SSB/La antibodies were more frequent, and anti-Sm and anti-cardiolipin antibodies were less prevalent in SLE-SS than SLE alone.

There are significant variances in certain clinical and laboratory aspects between SLE-SS and SLE. This combined disease of SLE-SS has distinct features with relatively less major internal organ involvement but has more specific autoantibody profile and favorable clinical outcome.