Detection significance of Th17 cells in peripheral blood of patients with rheumatoid arthritis in clinical remission

Abstract

To explore the significance and evaluate the early structural erosion through the expressions of Th17 cells in peripheral blood of patients with rheumatoid arthritis (RA) in clinical remission. A total of 41 active RA patients without structural erosion were selected. Intracelluar flow cytometric detection of Th17 cells in peripheral blood was performed. And the supernatant level of interleukin (IL)-17A was determined simultaneously in RA patients and control groups at baseline and endpoint of 24-month therapy. The correlations were analyzed between Th17 cells and RA disease activity index DAS28. They were classified into radiographic progression (P, n = 10) and radiographic non-progression groups (NP, n = 26) by the Sharp/van der Heijde score (SHS) at the endpoint. The differences of Th17 cells and IL-17A levels were analyzed between P (SHS > 0.5) and NP groups (SHS ≤ 0.5). The expression of Th17 cells in active RA patients was significantly higher than that of controls [(1.63 ± 0.45)% vs (0.91 ± 0.26)%, P < 0.01]. And the results of IL-17A level were similar [1510 ± 280) vs (320 ± 31) ng/L, P < 0.05]. The expression of Th17 cells was positively correlated with DAS28 score (r = 0.87, P < 0.01). Thirty-six RA patients were followed up at the endpoint and all of them stayed in clinical remission (DAS28 < 2.6). The peripheral blood expressions of Th17 cells of P group were significantly higher than those of NP group . At the same time, no differences of IL-17A levels existed between two groups. Structural erosion still progresses in some RA patients despite an apparent clinic remission. And a high-level peripheral expression of Th17 hints at structural erosion.