Adult Still's disease, a systemic inflammatory disorder of unknown etiology, shows few specific laboratory markers and histological features. We investigated T cell subsets in peripheral blood lymphocytes (PBL) of patients with adult Still's disease to elucidate immunological features of the disease.
We studied T cell subsets in PBL of 12 patients with adult Still's disease by flow cytometric analysis. T cell subsets were also investigated for more than 6 months in PBL of 3 patients with adult Still's disease.
Both the percentage and absolute number of T cell receptor gamma delta positive (TCR gamma delta +) T cells in active adult Still's disease (n = 6) were significantly (p < 0.05) higher than those in inactive adult Still's disease (n = 6), inactive rheumatoid arthritis (n = 8), or healthy controls (n = 20). An increase of TCR gamma delta + T cells was observed in 5 of 6 patients with adult Still's disease at the active phase. TCR gamma delta + T cells also increased for a considerable period in all the patients tested. In contrast, there were no significant differences in the other T cell subsets (CD3, CD4, CD8, TCR alpha beta) between all the patients and healthy donors. Levels of TCR gamma delta + T cells in PBL correlated well with those of serum ferritin and C-reactive protein in one of the 3 patients whose PBL could be serially investigated. These increased TCR gamma delta + T cells mostly consisted of a V gamma 9/V delta 2 subset.
TCR gamma delta + T cells in PBL are significantly increased in the active phase in patients with adult Still's disease.