BackgroundRheumatoid arthritis (RA) is a significant global health issue. Early diagnosis remains clinically challenging, particularly in patients with inflammatory arthritis who do not yet fulfill 2010 ACR/EULAR classification criteria (undifferentiated arthritis, UA).MethodsThis retrospective study enrolled 83 treatment-experienced RA (TE-RA), 49 treatment-naïve RA (TN-RA), and 51 seropositive UA patients, as well as 60 healthy controls.
Peripheral lymphocyte subsets and serum cytokines were profiled using flow cytometry and bead arrays. Least absolute shrinkage and selection operator (LASSO) regression was utilized to develop an immune-based derivation-stage classifier for distinguishing TN-RA from UA, with internal validation by bootstrap resampling (B = 1000).ResultsImmunophenotypic analysis identified distinct immune profiles between TN-RA and UA at initial presentation.
TN-RA was characterized by IL-2 signaling exhaustion (elevated sIL-2R, decreased IL-2), systemic inflammation (elevated IL-6, IFN-γ, and TNF-α), and compensatory memory Treg expansion (increased CD45RO+ Tregs). In contrast, UA exhibited a Th17/Treg imbalance with relatively preserved Th2 and Th17 responses.
Frontiers in Immunology published a clinical update in Infectious Disease on 09 Jun 2026.
The item focuses on Soluble IL-2 receptor and memory Treg profiles differentiate early rheumatoid arthritis from undifferentiated arthritis at initial presentation.
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