Altered T-cell subtypes in spondyloarthritis, rheumatoid arthritis and polymyalgia rheumatica

The objective of the present study was to assess the prevalences of naive, memory, memory/effector, regulatory and activated T-cells in peripheral blood (PB) and synovial fluid (SF) of patients with spondyloarthritis (SpA), rheumatoid arthritis (RA), polymyalgia rheumatica/giant cell arteritis (PMR/GCA) and healthy controls (HC). Twenty-two patients with SpA, 15 patients with RA, 38 patients with PMR/GCA and 17 HC were prospectively enrolled. The expression of differentiation and activation markers (CD3, CD4, CD8, CD25, CD28, CD45RA, CD45RO) characterizing T-cell subsets were analyzed by flow cytometry. The frequency of CD3⁺CD4⁺CD28⁻ memory/effector T-cells was increased in PB of patients with SpA (median 1.1%, range 0.1–69.6), RA (2.5%, 0–42.9) and PMR/GCA (2.7%, 0–49.5) when compared with HC (0.7%, 0–38.0) and tended to be higher in SF of SpA patients (4.5%, 0.2–7.2, P = 0.084). CD28⁺CD45RA⁺CD4⁺ (9.6%, 4.1–10.3) and CD28⁺CD45RA⁺CD8⁺ naive T-cells (15.0%, 12.9–26.2) were reduced and CD28⁺CD45RO⁺CD4⁺ (93.5%, 51.0–99.0), CD28⁺CD45RO⁺CD8⁺ memory (81.2%, 38.9–83.5), CD8⁺CD25⁺ activated T-cells (10.9%, 2.7–13.8) and CD4⁺CD25^hi TREGs (10.2%, 7.0–13.3) were increased in SF compared to PB (P < 0.05 each). These findings demonstrate altered T-cell subsets in patients with immune-mediated disease, particularly at sites of inflammation.