Predominance of Th1 cytokine in peripheral blood and pathological tissues of patients with active untreated adult onset Still's disease

Abstract

Objective: To determine the type 1 T helper (Th1)/type 2 T helper (Th2) balance in the peripheral blood (PB) and pathological tissues of patients with active untreated adult onset Still's disease (AOSD).

Methods: The percentages of interferon gamma (IFNgamma)- and interleukin (IL)4-producing Th cells in the PB of 20 patients with active untreated AOSD, 20 patients with active rheumatoid arthritis (RA), and 20 healthy controls were determined by intracellular staining and flow cytometry. Serum levels of IL18 and soluble IL2 receptor were measured by enzyme linked immunosorbent assay. Levels of IFNgamma and IL4 messenger (m) RNA expression were examined by real time quantitative polymerase chain reaction in biopsy specimens of evanescent rash and synovitis from 8 patients with AOSD.

Results: Significantly higher IFNgamma-producing Th cells and Th1/Th2 ratio in PB were found in patients with AOSD than in healthy controls. Percentages of IFNgamma-producing Th cells and Th1/Th2 ratio in PB correlated significantly with clinical activity score and serum IL18 levels in patients with AOSD. Increased ratio of Th1/Th2 cytokine transcripts was seen in the biopsy specimens of evanescent rash and synovitis from patients with AOSD compared with normal skin controls and patients with OA. Th cell cytokine pattern in PB and cytokine mRNA expression in synovium were similar for patients with AOSD and with RA. After 3 months' treatment, clinical remission was associated with a marked decrease in the percentages of cytokine-producing Th1 cells, but not of the Th2 cells.

Conclusion: A predominance of Th1 cytokine may precipitate the pathogenesis of AOSD.

Figure 1

Flow cytometric dot plots of intracellular cytokine production in Th cells obtained from PB of (A) one represented patient with active untreated AOSD; (B) one patient with active RA; and (C) one HC after stimulation with PMA/ionomycin in the presence of brefeldin A. The figure in the quadrants denotes the percentage of cells expressing IFNγ or IL4 in CD4+ T cells. Mean percentages of (D) IFNγ-; (E) IL4-producing Th cells; and (F) the Th1 (IFNγ)/Th2 (IL4) ratio in Th cells obtained from the PB of patients with active untreated AOSD, active RA, and the HC. Horizontal bars indicate means. The p values are provided for comparison of these three groups.

Figure 2

The ratio of Th1 (IFNγ)/Th2 (IL4) mRNA expression in the biopsy skin (A) of evanescent rash from patients with AOSD (n = 8) and from normal controls (NC, n = 4), and in the biopsy synovium (B) of active synovitis from patients with AOSD (n = 6), of active synovitis from patients with RA (n = 6) and OA controls (n = 4) was analysed by the real time TaqMan PCR method. Data are presented as mean (SEM). The p values are provided for comparison of different groups.

Figure 3

Serum levels of IL18 in patients with active untreated AOSD, active RA, and healthy controls (HC). Horizontal bars indicate means. The p values are provided for comparison of the three groups.

Figure 4

Serial changes in (A) the levels of IL18 and sIL2R in serum, and in (B) the mean percentage of IFNγ-and IL4-producing Th cells in PB of 12 patients with AOSD before treatment and at 1 and 3 months after treatment with GC, NSAIDs, and methotrexate. Data are presented as mean (SEM).