Data on the impact of biological therapies, especially of IL6-blocker treatment, on the T-cell phenotype in rheumatoid arthritis (RA) are limited, inconclusive, and mainly involve short-term follow-up.

Here, the investigator prospectively measure the percentages of 15 circulating T-cell subtypes using flow cytometry. The investigators aim to obtained transversal and longitudinal data in 30 anti-TNF responders, 19 secondary anti-TNF-non-responders, 43 IL6R-antagonist-responders before, 8 weeks and, after, at least, 6 months of biological therapy. These are then compared with results obtained in early, untreated RA patients and gender-and-age matched healthy controls.

Inclusion Criteria for patients:

• Diagnosis of rheumatoid arthritis classified according to the 2010 ACR/EULAR classification criteria for RA
• Biological treatment with anti-TNF therapy (adalimumab or certolizumab pegol or etanercept or infliximab or golimumab) or anti-IL-6R agent (tocilizumab)

Inclusion Criteria for healthy controls:

• negative history of RA symptoms
• negative status upon detailed physical and laboratory examination including normal CRP and ESR values

Exclusion Criteria:

• other autoimmune comorbidity
• lack of informed consent

In the cross-sectional analysis, 92 RA patients (who had been treated with biological therapy for more than six months) were evaluated.

As a further control group (healthy controls), we enrolled 30 age- and gender-matched healthy volunteers.

Upon request