Effect of recombinant human IFNγ in the treatment of chronic pulmonary complications due to sulfur mustard intoxication.

Pulmonary problems are among the most common chronic complications of sulfur mustard (SM) intoxication and adversely affect patients' quality-of-life. The present trial investigated the impact of immunotherapy with interferon (IFN)-γ on quality-of-life, respiratory symptoms, and circulating immunologic and oxidative parameters in patients suffering from chronic SM-induced complications. Patients (n = 15) were administered IFNγ (100 μg) every other day for a period of 6 months. Assessment of quality-of-life [using St. George respiratory Questionnaire (SGRQ) and COPD Assessment Test (CAT) indices], the severity and frequency of respiratory symptoms, and serum levels of immunologic [including interleukin (IL)-2, IL-4, IL-6, IL-10, IFNγ, calcitonin gene related peptide (CGRP), matrix metallopeptidase (MMP)-9, and tumor necrosis factor (TNF)-α], oxidative stress [malondialdehyde (MDA) as well as total and reduced glutathione, and catalase and superoxide dismutase (SOD) activity], and fibrogenic [transforming growth factor (TGF)-β] parameters were performed at baseline and at trial end. The results indicated that IFNγ therapy is associated with improvements in SGRQ (p < 0.001) and CAT (p < 0.001) scores, decreased severity of cough (p = 0.001), dyspnea (p < 0.001), and morning dyspnea (p < 0.001), reduced frequency of sputum production (p < 0.001) and hemoptysis (p < 0.001), and elevated FEV1 (p = 0.065). Serum levels of IL-4 (p < 0.001), IL-6 (p < 0.001), IL-10 (p < 0.001), CGRP (p < 0.001), MMP-9 (p = 0.001), TNFα (p < 0.001), TGFβ (p < 0.001) and MDA (p = 0.001) were decreased while those of IL-2 (p < 0.001), IFNγ (p < 0.001), and both total (p = 0.005) and reduced glutathione (p = 0.061) increased by the end of the trial. It was concluded that IFNγ has favorable effects on the quality-of-life and alleviates respiratory symptoms in patients suffering from chronic SM-induced pulmonary complications. A modulation of cytokines and oxidative stress appears responsible for the clinical efficacy of IFNγ.