Fig. 1

The frequency of NKT cells is increased in the lung of CTD-IP patients. Representative hematoxylin and eosin (HE) stained lung sections from healthy control (a, b) and enrolled CTD-IP patients (n = 6) (d, e) showing areas of sub-acute alveolar damage accompanied by capillary remodeling (d, e) and lymphoid follicle formation (d, e) in CTD-IP. Lung sections stained with Masson trichrome (MT) and immunostaining showed increased collagen deposition (blue, g), combined with enhanced expression of α-SMA (brown, f) in capillaries and interstitial cells compared with healthy control (brown, c). Positive CD3 immunostaining was located in the lymphoid follicles (brown, h). The arrows indicate myofibroblast infiltration with α-SMA-positive staining or T cells with CD3-positive staining. (a, d) 100× magnification, (b), (c), (e) to (h) 400× magnification. i Flow cytometric analysis of BALF cells, percentage of CD3⁺, CD3⁺ CD4⁺, CD3⁺ CD8⁺, CD3⁺ CD56⁺ cells gating on leucocytes and CD8⁺/CD4⁺ are presented, and the means ± SD of six cases are shown. α-SMA α-smooth muscle actin, BALF bronchoalveolar lavage fluid