49

Introduction: Common Variable Immunodeficiency (CVID) is the most common symptomatic form of primary immunodeficiencies. Current research data show altered B cells, TLRs, and cytokine profile in CVID patients. The aim of this study was to determine levels of IL-1β and IL-6 in CVID patients in response to TLRs stimulation and the association of these cytokines with subtypes of B cells and response to Pneumovax-23 vaccination. Method: Peripheral blood mononuclear cells of CIVD patients were stimulated with and without TLR2 and TLR4 agonist and specific inhibitors including lipopolysaccharide (LPS), lipoteichoic (LTA), and OxPAPC. The levels of IL-1β and IL-6 were assessed by ELISA in different treatment groups. Finally, association of cytokines levels was assessed among different subtypes of B cells and types of response to Pneumovax-23 vaccine. Results: Secretion of IL-6 and IL-1β was significantly diminished in CVID patients (p = 0.015 and p = 0.019), but ligand engagement of TLR2 and TLR4 leads to significant increase in IL-6 and IL-1β production. IL-6 was significantly lower in Pneumovax-23 hypo responder patients (p = 0.05) and significant correlations between the concentration of IL-6 and the number of switched memory and CD21low expressing B cells were found. Conclusion: Secretion of IL-6 and IL-1β is abolished in CVID patients. However, TLR2 and TLR4 are hyper responsive to stimulation with their cognate ligands resulting in the secretion of higher levels of proinflammatory cytokines. This characteristic of CVID TLRs leads to an improvement of cytokine secretion compared to baseline levels. Also, our novel findings about the association concentrations of serum IL-6 and the frequency of with switched memory and CD21low expressing B cells as well as the poor response to Pneumovax-23 should be substantiated by the use of a higher sample size in future studies.