Abnormalities of B cell phenotype, immunoglobulin gene expression and the emergence of autoimmunity in Sjögren's syndrome

Abstract

Primary Sjögren's syndrome (pSS) is an autoimmune disorder characterized by specific pathologic features and the production of typical autoantibodies. In addition, characteristic changes in the distribution of peripheral B cell subsets and differences in use of immunoglobulin variable-region genes are also features of pSS. Comparison of B cells from the blood and parotid gland of patients with pSS with those of normal donors suggests that there is a depletion of memory B cells from the peripheral blood and an accumulation or retention of these antigen-experienced B cells in the parotids. Because disordered selection leads to considerable differences in the B cell repertoire in these patients, the delineation of its nature should provide important further clues to the pathogenesis of this autoimmune inflammatory disorder.

Figure 1

Analysis of the distribution of peripheral CD19⁺ B cell subsets demonstrates that patients with primary Sjögren's syndrome (pSS) have reduced frequencies of CD27⁺ memory B cells in the peripheral blood compared with normal donors. In addition, patients with pSS with secondary non-Hodgkin lymphoma exhibited an increase in CD27⁺ B cells in the blood.

Figure 2

Schematic distribution of B cell subsets in peripheral blood of normals compared with patients with systemic lupus erythematosus and Sjögren's syndrome.