Is the blood B-cell subset profile diagnostic for Sjogren syndrome?

OBJECTIVE: To evaluate the relevance of the blood B-cell subset profile for the diagnosis of Sjögren syndrome. METHODS: The distribution of mature blood B cells from Bm1 through Bm5 was determined in 161 patients, of whom 25 fulfilled the American-European Consensus Group criteria for primary SS (pSS), and 136 served as disease controls. RESULTS: The percentage of Bm2 and Bm2' cells was increased in the patients with pSS compared with 54 patients with rheumatoid arthritis (RA) and 18 with systemic lupus erythematosus (SLE) (p<0.001 for the two comparisons). In contrast, those of early Bm5 (eBm5) and Bm5 were decreased in patients with pSS, compared with patients with RA and with SLE (p<0.001 for the two comparisons). The receiver operating characteristic curves allowed for an optimising cut-off value of Bm2+Bm2' cells at 71.1% for 88.0% sensitivity and 83.1% specificity, that of eBm5+Bm5 cells at < or =13.5% for 84.0% sensitivity and 83.1% specificity, and, consequently, that of Bm2+Bm2'/eBm5+Bm5 at > or =5 for 88.0% sensitivity and 84.6% specificity. CONCLUSION: Given its presentation as a signature for pSS, relative to RA and SLE, such a distribution of B-cell subsets might provide a useful diagnostic tool.

[B lymphocytes in Sjögren's syndrome]. / Les lymphocytes B dans le syndrome de Gougerot-Sjögren.

INTRODUCTION: Sjögren's syndrome (SS) is an autoimmune epithelitis hallmarked by a disruption of epithelial cells, the subsequent lymphocytic infiltration of lachrymal and salivary glands (SGs), and their ensuing dryness. One may posit that SS is triggered by viruses, and/or modulated by sex steroid hormones, and there is indeed a consensus that its aetiology is multifactorial, with genetic factors interacting with environmental agents. CURRENT KNOWLEDGE AND KEY POINTS: T-cells have long occupied central stage of the debate on the type of lymphocytes involved in the pathogenesis of SS. The relevance of B cells has, however, been emphasized over the past five years and new insights into their functions revealed. Furthermore, increased levels of the B-cell activating factor (BAFF) may be responsible for quantitative and qualitative anomalies of B-cells found in SS such as emergence of self reactive B-cells. This review reports compelling evidence that B-cells are involved in the pathophysiology of SS. PROSPECTS: Since SS may thus be conceived as a model for B-cell-induced autoimmunity, it is no surprise that B-cell ablative-treatment has proven to be relatively effective in SS.