Objective: To identify whether the helper T lymphocyte 1 (Th1)/helper T lymphocyte 2 (Th2) of patients' serum and bronchoalveolar lavage fluid (BALF) at admission could represent the severity of idiopathic pulmonary fibrosis (IPF) and whether its change at six months could predict the progression of the disease.
Methods: Eighty-three patients with IPF were subjected to pulmonary function tests (PFTs), dyspnea scores, arterial blood gas analysis, six-minute walk test (6MWT) and high-resolution computed tomography (HRCT). The serum and BALF specimen of these patients were obtained as well as 20 control serum and 10 control BALF specimen. A total of 55 patients were followed up, and their BALF and serum levels of interferon γ(IFNγ) and IL-4 were detected by enzyme-linked immunoadsorbent assay (ELISA). The correlation between the IFNγ/IL-4 levels (at admission and the change of that at six months follow-up) and the clinical, physiological and image features in the IPF patients were analyzed.
Results: The baseline serum and BALF level of IFNγ/IL-4 (0.8 ± 0.3) in the IPF patients was lower than that in the control group (1.4 ± 0.2), which showed significant correlation with the course of disease, dyspnea scores, FEV1%, FVC%, TLC%, maximum desaturation, 6MWD and CT-fib (all P values<0.05). The serum level of IFNγ/IL-4 showed positive correlation with CT-alv (r = 0.340, P<0.01). During follow-up, no statistic difference was found in the serum levels of IFNγ, IL-4 and IFNγ/IL-4 between the IPF patients with or without glucocorticoids treatment. There were significant aggravation in the dyspnea scores, FEV₁%, FVC%, CT-alv, CT-fib, IFNγ and IL-4 at six months follow-up. Significant correlation had been showed between the change of the serum IFNγ/IL-4 level with the changes of the dyspnea scores, FVC%, TLC%, DLCO%, 6MWD and CT-fib in the IPF patients (P < 0.05).
Conclusions: There are disequilibrium of the Th1/Th2 in the serum and the BALF of the IPF patients. The Th1/Th2 level could represent severity of the disease, and the serum level change of Th1/Th2 in the follow-up could predict the progression of the diseases in the IPF patients.