Gene expression analysis of anti-TNF-treated rheumatoid arthritis patients reveals the links between NADPH oxidase expression profile and immunophenotypic changes in peripheral blood mononuclear cells

Abstract

Objectives The aim of this research was to prospectively evaluate the impact of NOX2 gene expression profile (including NCF1, NCF2 and NCF4 genes) in peripheral blood mononuclear cells (PBMCs) on immune signatures, clinical characteristics and responsiveness to anti-TNFα treatment in RA patients. Methods Blood specimens were collected from rheumatoid arthritis (RA) patients and healthy control pairs before anti-TNF treatment and 16 RA patients were followed at two timepoints (months 3 and 6) populations were determined based on mRNA expression of nine selected genes (NCF1, NCF2, NCF4, TNFα, CD14, FCGR3A, CXCR3, CXCR4, CX3CR1). Four immunoregulatory cytokines concentrations during anti-TNF treatment. NADPH oxidase profile and immunophenotypic characteristics of monocytes and lymphocytes (IFN-alpha, IFN-beta, IL-17A, IL-10) were measured by ELISA. Differences between RA patients before and during anti-TNF treatment as well as between responders and non-responders were assessed. Results We observed the significant upregulation of NCF4 and CD14 expression in RA group. After anti-TNFα treatment, we demonstrated a significant association between mRNA levels of NCF1 and TNFα. The mRNA levels of NCF1 and CD14 positively correlated both in RA patients before anti- TNFα treatment (p = 0.03) and healthy controls (p = 0.014). Although no associations were found between NOX2 gene expression profile and anti-TNF responsiveness, we found that CXCR3 is significantly overexpressed in non-responders at month 3 (p = 0.004). Conclusions In contrary to previous reports we observed no relationships between NOX2-related genes expression and RA activity. TNFα inhibition has not influenced NOX2 expression either. Notably, this study indicate the novel links between expression levels of NCF1, monocyte differentiation antigen CD14 and TNFα. The additional finding of the study was the potential predictive value of CXCR3 expression for clinical response to anti-TNFα agents.