Increased IL-6 and TGF-β1 concentrations in bronchoalveolar lavage fluid associated with thoracic radiotherapy

Abstract

PurposeTo assess, in lung cancer patients, the effects of thoracic radiotherapy (RT) on the concentrations of transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6) in the bronchoalveolar lavage (BAL) fluid. Methods and materialsEleven patients with lung cancer requiring RT as part of their treatment were studied. BAL was performed bilaterally before, during, and 1, 3, and 6 months after RT. Before each BAL session, the patient's status was assessed clinically using pulmonary function tests and an adapted late effects on normal tissue-subjective, objective, management, analytic (LENT-SOMA) scale, including subjective and objective alterations. The National Cancer Institute Common Toxicity Criteria were used to grade pneumonitis. The TGF-β1 and IL-6 levels in the BAL fluid were determined using the Easia kit. ResultsThe TGF-β1 and IL-6 concentrations in the BAL fluid recovered from the irradiated areas were significantly increased by thoracic RT. The increase in TGF-β1 levels tended to be greater in the group of patients who developed severe pneumonitis. In the BAL fluid from the nonirradiated areas, the TGF-β1 and IL-6 concentrations remained unchanged. ConclusionThe observed increase in TGF-β1 and IL-6 concentrations in the BAL fluid recovered from the irradiated lung areas demonstrated that these cytokines may contribute to the process leading to a radiation response in human lung tissue.