Analysis of age-associated B cells (ABCs) in Systemic Lupus Erythematosus (SLE) patients

Abstract

Abstract SLE is an autoimmune disease which is characterized by the formation of auto-antibodies and loss of tolerance. In addition to the production of auto-antibodies, certain sub-populations of B cells may play a critical role in the resolution or severity of the disease. Recently, a novel CD11c+, CD21low, and T-bet+ expressing B-cell subset has been identified as critical for the development of autoimmune diseases; the transcriptional program that develops this phenotype is induced in response to signaling by IFN-γ, TLR-9 and the costimulatory molecule CD40 and is linked to the induction of IgG2a, IgG2b, IgG3 and repression of IgG1 and IgE. However, the relationship between the presence of these cells and autoimmunity development is not yet well understood. In this study, we analyzed blood samples from a cohort of 15 patients with SLE through flow cytometry. The frequency of this ABCs sub-population was correlated with clinical and laboratory variables such as C3, C4, antidsDNA antibodies, anti-nucleosomes antibodies, serum creatinine and total urine proteins. These data were subjected to Spearman’s correlation analyses. Interestingly, we found a positive correlation with ABCs percentages and anti-dsDNA antibodies (r=0.604, p=0.028). These results suggest that circulating ABCs number can be potentially used as a diagnostic/prognostic marker for this autoimmune disease.