Follicular Helper T Cells in Peripheral Blood of Patients with Rheumatoid Arthritis

San Francisco

Encuentro; 2015 ACR/ARHP Annual Meeting; 2015

American College of Rheumatology (ACR)

Background/Purpose: RA is an autoimmune, inflammatory and chronic disease which aetiology is unknown. It presents different autoantibodies such as RF and ACPA. A population of CD4 T cells expressing CXCR5, Bcl6, PD-1, ICOS, CD40L and IL-21, named Follicular helper T cells (Tfh), collaborates with B cells to produce antibodies. Increased levels of peripheral blood Tfh cells have been implicated in the development of systemic autoimmunity. Differential expression of CXCR3 and CCR6 whitin CD4+CXCR5+ T cells defines three mayor subset: CXCR3+CCR6- (Tfh1), CXCR3-CCR6- (Tfh2) and CXCR3-CCR6+ (Tfh17). The aim is to ascertain if differents subsets of CD4+CXCR5+ T cells are alterated in RA patients and if their percentages correlate with disease activity.Methods: In this study participated RA patients (n=24), healthy controls (HC) (n=22) and undifferentiated arthritis (UA) patients (n=16) (Table 1). Percentage of CD4+CXCR5+ T cells and their subsets CXCR3+CCR6-, CXCR3-CCR6- and CXCR3- CCR6+ from PBMCs were analysed by flow cytometry. Pearson or Spearman correlation coefficients were used for statistics. Results: Figure 1 shows flow cytometry analysis. No differences were found in the % of CD4+CXCR5+ T cells between RA vs HC or RA vs UA (mean±SD, RA 12,89±7,73; HC 10,48±3,9; UA 11,71±5,04). Either in the % of Tfh1 (12,75 ± 9,72; 11,22 ± 7,48; 12,81 ± 6,13), or Tfh2 (32,66 ± 11,46; 39,53 ± 12,12; 27,56 ± 11,25), or Tfh17 subsets (37,94 ± 11,34; 40,79 ± 8,17; 37,34 ± 7,16) between previous groups (Figure 2). There was not correlation between CD4+CXCR5+ T cells (r=-0,19 p=0,37 ), or Tfh1 (r=0,09 p=0,68 ), or Tfh2 (r=0,36 p=0,09 ), or Tfh17 (r=-0,20 p=0,35 ) vs DAS-28, like either between each subset and ESR ( r=-0,18 p=0,39, r=-0,08 p=0,71, r=-0,01 p=0,97, r=-0,25 p=0,23, respectively). Unexpectedly, there was positive correlation between Tfh17 cells and CRP r=0,47 p=0,021. Finally, there was not correlation between CD4+CXCR5+ T cells vs mutated citrullinated vimentin (MCV) r= 0,38 p=0,07, either between Tfh1, Tfh2 and Tfh17 subsets vs MCV( r=-0,04 p=0,84, r=-0,14 p=0,51, r=-0,19 p=0,37, respectively) or all of them vs RF (r=0,30 p=0,15, r=-0,18 p=0,39, r= -0,15 p=0,46, r=0,01 p=0,98, respectively). Conclusion: In concordance with our results, CD4+CXCR5+ T cells and their subsets would not be involved in the RA development.