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.