Activation of pulmonary T cells in corticosteroid-resistant and -sensitive interstitial pneumonitis in dermatomyositis/polymyositis

Abstract

To study the activation states and cytokine profiles of pulmonary T cells in corticosteroid-resistant and corticosteroid-sensitive interstitial pneumonitis (IP) in dermatomyositis (DM)/polymyositis (PM), we examined the activation markers and cytokine profiles of T cells in bronchoalveolar lavage fluids (BALF) from patients with IP in DM/PM before prednisolone therapy and then compared the activation states of T cells according to the therapeutic response of IP to prednisolone therapy. CD25+ CD4+ T cells in BALF were significantly increased in both corticosteroid-resistant and corticosteroid-sensitive IP in DM/PM as compared with those in controls without IP. Furthermore, CD25+ CD4+ T cells in BALF were significantly more increased in corticosteroid-resistant IP than those in cortico teroid- sensitive IP. Moreover, CD25+ CD8+ T cells in BALF were significantly increased only in corticosteroid-resistant IP, but not in corticosteroid-sensitive IP or controls without IP. IFN-gamma mRNA was detected in BALF T cells in corticosteroid-resistant and corticosteroid-sensitive IP but not in controls without IP, whereas IL-4 mRNA was virtually undetected in BALF T cells in both the IP groups. However, there were no significant differences in CD4/CD8 ratio of BALF T cells, HLA-DR+ BALF T cells or CD25+ and HLA-DR+ peripheral blood T cells between the two IP groups. These results indicate that activated Th1-type pulmonary T cells play an important role in the development of corticosteroid- resistant IP in DM/PM and that the increase in CD25+ CD8+ T cells in BALF is a useful indicator for corticosteroid-resistant IP in DM/PM and hence may be an indicator for early use of cyclosporin.

Fig. 1

Cellular components of bronchoalveolar lavage fluid (BALF) in dermatomyositis (DM)/polymyositis (PM) patients with corticosteroid-resistant and corticosteroid-sensitive interstitial pneumonitis (IP). Prior to corticosteroid therapy, BALF was obtained from DM/PM patients with corticosteroid-resistant IP (n = 6, ▪) and corticosteroid-sensitive IP (n = 16,) and from controls without IP including DM patients without IP (n = 12, □), and the number of total cells, lymphocytes, macrophages, neutrophils, and eosinophils in BALF was evaluated. Data are means ± SD in each group. Significant different from the mean values in controls without IP, *P < 0·05, **P < 0·005.

Fig. 2

CD4/CD8 ratio of BALF T cells in DM/PM patients with corticosteroid-resistant and corticosteroid-sensitive IP. BALF cells from DM/ PM patients with corticosteroid-resistant IP (n = 6) and corticosteroid- sensitive IP (n = 16) and from controls without IP (n = 12) were stained with anti-CD4-FITC, anti-CD8-PerCP, and anti-CD3-PE antibodies and analysed by FACS. • DM patients, ▪ PM patients, ▴ lung cancer patients without IP.

Fig. 3

Increase in CD25⁺ T cells in BALF in DM/PM patients with corticosteroid-resistant IP. BALF cells from DM/PM patients with corticosteroid-resistant IP (n = 6) and corticosteroid-sensitive IP (n = 16) and from controls without IP (n = 12) were stained with (a) anti-CD4-FITC and (b) anti-CD8-PerCP and anti-CD25-PE antibodies and analysed by FACS. • DM patients, ▪ PM patients, ▴ lung cancer patients without IP. *P < 0·005, **P < 0·001.

Fig. 3

Increase in CD25⁺ T cells in BALF in DM/PM patients with corticosteroid-resistant IP. BALF cells from DM/PM patients with corticosteroid-resistant IP (n = 6) and corticosteroid-sensitive IP (n = 16) and from controls without IP (n = 12) were stained with (a) anti-CD4-FITC and (b) anti-CD8-PerCP and anti-CD25-PE antibodies and analysed by FACS. • DM patients, ▪ PM patients, ▴ lung cancer patients without IP. *P < 0·005, **P < 0·001.

Fig. 4

Increase in HLA-DR⁺ T cells in BALF in DM/PM patients with corticosteroid-resistant and corticosteroid-sensitive IP. BALF cells from DM/PM patients with corticosteroid-resistant IP (n = 6) and corticosteroid-sensitive IP (n = 16) and from controls without IP (n = 12) were stained with (a) anti-CD4-FITC and (b) anti-CD8-PerCP, and anti-HLA-DR-PE antibodies and analysed by FACS. • DM patients, ▪ PM patients, ▴ lung cancer patients without IP. *P < 0·001.

Fig. 5

IFN-γ and IL-4 mRNA expression in BALF T cells from DM/PM patients with corticosteroid-resistant and corticosteroid- sensitive IP.IFN-γ and IL-4 mRNA expression was detected by PCR amplification of cDNA from BALF T cells in DM/PM patients with corticosteroid-resistant IP (n = 6) and corticosteroid-sensitive IP (n = 16) and controls without IP (n = 12). TCR Cβ mRNA expression was used as an internal control of PCR amplification of cDNA. The PCR products were run on 1·5% agarose gel, and visualized using ethidium bromide. The data shown are representative of corticosteroid-resistant IP (lanes 1–4), corticosteroid-sensitive IP (lanes 5–8), and controls without IP (lanes 9 and 10). P, activated peripheral blood T cells as a positive control.