The implication of interferon‐γ‐producing immunocompetent cells for evaluating disease activity and severity in adult‐onset Still's disease. (9th July 2021)

• Record Type: Journal Article
• Authors: Ichikawa, Takanori; Shimojima, Yasuhiro; Kishida, Dai; Ueno, Ken‐ichi; Sekijima, Yoshiki
• Is Part Of: International journal of rheumatic diseases. Volume 24:Number 9(2021)
• Page Start: 1176
• Page End: 1185
• Publication Date: 2021-07-09
• Subjects: adult‐onset Still's disease -- CD4+ cells -- interferon‐γ -- interleukin‐12 -- interleukin‐18 -- NK cells; Rheumatology -- Periodicals; Rheumatology -- Asia -- Periodicals; Rheumatology -- Pacific Area -- Periodicals; Rheumatic Diseases -- Periodicals; Connective Tissue Diseases -- Periodicals; Immune System Diseases -- Periodicals; 616.723
• DOI: 10.1111/1756-185X.14171
• Languages: English
• ISSNs: 1756-1841

Abstract

Abstract: Objective: To investigate the relationship between interferon‐γ (IFN‐γ), IFN‐γ‐producing immunocompetent cells, their related cytokines, and the clinical features in adult‐onset Still's disease (AOSD). Methods: Twenty‐five patients with AOSD before initiating treatment (acute AOSD), 9 patients after remission (remission AOSD), and 12 healthy controls (HC) were included. Circulating IFN‐γ‐producing CD4+ and CD8+ cells, natural killer (NK) cells, and IFN‐γ production in NK cells were evaluated by flow cytometry. Serum levels of IFN‐γ, interleukin (IL)‐6, IL‐12, IL‐15, and IL‐18 were also measured. The obtained results were statistically analyzed with clinical findings. Results: Serum levels of IFN‐γ, IL‐6, IL‐12, IL‐18, intracellular expression of IFN‐γ in CD4+, CD8+, and NK cells were significantly higher in acute AOSD than in HC. The proportion of NK cells was significantly lower in acute AOSD than in HC. Serum levels of IFN‐γ and IFN‐γ expression in CD4+ cells were significantly correlated with serum ferritin levels. The proportion of NK cells had a significant inverse correlation with serum IFN‐γ levels. A lower proportion of NK cells was significantly noted in patients refractory to initial immunosuppressive treatment. In remission AOSD, serum levels of IL‐6, IL‐12, and IL‐18 were significantly higher than in HC. Conclusion: Increased serum levels of IFN‐γ, increased expression of IFN‐γ in CD4+ cells, and decreased NK cell proportion correlate with disease activity in AOSD. Moreover, a lower proportion of NK cells may be useful for predicting a refractory clinical course. Meanwhile, increased serum levels of IL‐6, IL‐12, and IL‐18 may persist after clinical remission.