Background T cell subset dys-regulation was previously shown to predict the ability to achieve remission in early rheumatoid arthritis (RA), independently of the treatment received. Naïve cells frequency were the most discriminative circulating T cells although cytokine activated T cells (IRC) were informative. The aim of the current study is to determine whether T cell subset analysis performed within 4 h of blood collection can discriminate early between patients that will evolve towards UA or RA.
Methods 70 patients with <12 months IA were enrolled; age, DAS, CRP, symptom duration, RF and ACPA were included in the analysis. 6 colour flowcytometry was performed using standard protocols. 55 healthy controls (HC) were included to calculate age-corrected expected naïve cell frequency.
Results Using newly developed 2010-RA criteria for diagnostic, 49 of the 70 patients evolved to RA, 11 remaining unclassified (UA). RA was associated with younger age (p=0.05, median 46 years compared to UA 65 years), higher DAS28 (p=0.008) compared to UA. There was no difference in symptom duration or RF. Naïve T cells are difficult to measure in the sixth decade as they decrease with age (R=−0.672, p<0.001 using HC) therefore, we accounted for this by calculating the deviation from normal expected naive cell frequency in patients. UA patients showed minimal deviation (median variation +8%) from expectation, whereas RA patients showed loss of naïve T cells (median -5%, p=0.037). Symptom duration and reduction of naïve cell were also correlated in RA (R=−0.528, p=0.020) in patients <6th decade of age. IRC were significantly increased in both UA and RA (p<0.006) compare to HC. Treg were reduced in the UA group compared to HC (p=0.028) but not RA in whom Treg were very variable. Binary logistic confirmed 4 parameters identifying RA: age<48 (p=0.0126), DAS28>3.2 (p=0.022), CRP>10 mg/l (p=0.026) and reduced naïve T cells (p=0.041). Patients fulfilling these three clinical RA parameters were all RA. In the 32 patients failing one or two of these three parameters, reduced naïve T-cells identified 94% of these patients as RA. UA patients showed normal naïve T-cells in 87% patients analysed.
Conclusion There is clear immunological difference between UA and RA diagnosed using the new 2010-criteria: loss of naïve T cells appear particularly important with the appearance of IRC. Treg appear to have limited predictive value.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.