Anti-dsDNA specific antibody secreting cells are increased in both frequency and abundance in Chronic Rhinosinusitis with Nasal Polyps

Abstract

Abstract Background We have previously found that anti-dsDNA IgG autoantibodies are increased in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) patients. Recent studies find that B cells with the Epstein-Barr virus-induced protein 2(EBI2), is critical to the extrafollicular response. We have described elevated numbers of EBI2+ B cells in NP and they were more frequently antibody secreting cells (ASCs). In this study we evaluate whether dsDNA-specific ASCs are increased in NP and further compared the EBI2+ and EBI2− compartments. Methods To investigate this problem, flow cytometry and ELISpot assays were utilized to compare the frequency of total IgG and dsDNA specific IgG ASCs and cells were sorted into EBI2+ and EBI2− B cells from human NP and tonsils. Results Flow cytometry results (n=10 tonsil, 4 NP) found that although tonsils had significantly more B cells than NP, a significantly smaller proportion were CD27+CD38+ plasmablasts (PB). Further ELISpot analysis found NP B cells were more frequently IgG ASCs than tonsil (0.06% and 0.43% in tonsil (n=9) and NP (n=5) respectively, p<0.001). Anti-dsDNA specific ASCs were two-fold more in NP representing 0.95% of IgG ASCs compared with 0.4% in tonsil ASCs (p<0.05). In analysis of ASCs sorted from tonsils (n=3) and NP (n=2), we found anti-dsDNA IgG ASCs were more frequent among EBI2+ compared to EBI2− cells with 10- and 14-fold increases in dsDNA reactivity (p<0.01). Conclusions Although B-cells are significantly more abundant in tonsils, NP derived B-cells more frequently secrete total- and dsDNA-specific IgG. These differences appear to be driven by extrafollicular EBI2+ B-cells suggesting that EBI2+ B cells represent the major pool of autoreactive B-cells observed in CRSwNP and tonsils.