Abnormal B cell differentiation in primary Sjögren's syndrome results in a depressed percentage of circulating memory B cells and elevated levels of soluble CD27 that correlate with Serum IgG concentration.
Detection of multiple Ig heavy-chain transcripts in peripheral CD19+,CD27+ memory B cells of patients with SS may represent the abnormal retention of pre-switch mRNA transcripts in circulating post-switch B cells.
Finally, compared with controls, peripheral reduction but glandular accumulation of CXCR4+,CXCR5+,CD27+ memory B cells was identified in patients with primary SS.
CD70, a B cell costimulatory molecule that interacts with CD27 during B-T cell contact, is overexpressed due to demethylation of its promoter regulatory elements in CD4+ T cells from patients with the following autoimmune diseases, namely systemic lupus erythematosus (SLE), subacute cutaneous lupus erythematosus (SCLE) and primary Sjögren's syndrome (pSS).