Abstract
Diffuse interstitial lung disease (DILD) is a heterogeneous group of disorders, in pathophysiology and pathogenesis of which, certain immunological processes are highly suggested. To determine which immunological reaction is mainly concerned, activated T and B cells in peripheral blood and in BALF were evaluated for various types of DILD: sarcoidosis (SAR), chronic beryllium disease (CBD) hypersensitivity pneumonitis (HP), idiopathic interstitial pneumonia (TIP), and interstitial pneumonitis associated with collagen-vascular disorder (IP-CVD).
Activated T cells were calculated by counting the number of lymphocytes which formed stable rosettes with non-neuraminidase treated SRBC at 37°C (E 37°C), and activated B cells by counting the spontaneous immunoglobulin secreting cells (IgSC) detected by reverse hemolytic assay.
Activated T cell levels were significantly higher in SAR, CBD, and HP, with moderate increase in IgSC. While activated T cells also increased in TIP and IP-CVD, the increase in IgSC, i.e., activated B cells was even more marked in these diseases. Activated lymphocyte levels were always higher in BALF than in the blood.
These findings suggest that DILD might more effectively be classified into two groups, i.e., T Lymphocyte Alveolitis: sarcoidosis, chronic beryllium disease, and hypersensitivity pneumonitis, and B Lymphocyte Alveolitis: idiopathic interstitial pneumonia and interstitial pneumonitis associated with collagen-vascular disorder.
