Altogether, both B cell hyperactivity and striking abnormalities in peripheral B cell memory are indicated at the single-cell mRNA level in patients with primary SS. 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.

Objective. To assess whether abnormal chemokine receptor expression and/or abnormal responsiveness to the cognate ligands might underlie some of the disturbances in B cell homeostasis characteristic of primary Sjögren's syndrome (SS).Methods. Chemokine receptor expression by CD27؊ naive and CD27؉ memory B cells from patients with primary SS and healthy control subjects was analyzed using flow cytometry, single-cell reverse transcriptase-polymerase chain reaction (RT-PCR), and migration assays.Results. In contrast to healthy subjects, significantly higher expression of both surface CXCR4 and CXCR4 messenger RNA (mRNA) was seen in peripheral blood B cells from patients with primary SS. These differences were most prominent in CD27؊ naive B cells (P < 0.0006). In addition, significantly higher frequencies of CD27؊ naive B cells from patients with primary SS expressed mRNA for the inhibitory regulator of G protein signaling 13 (P ‫؍‬ 0

No abstract