The measurements of plasma cytokines in radiation-induced pneumonitis in lung cancer patients

To investigate whether changes in plasma concentrations of transforming growth factor-β 1(TGF-β 1), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (lL -6) could be used to identify the development of radiation-induced pneumonitis in the lung cancer patients. Seventeen patients with lung cancer (11 NSCLC. 6 SCLC) were enrolled in a prospective study designed to evaluate clinical and molecular biologic correlation of radiation-induced pneumonitis. The study began in May 1998 and completed in July 1999. All patients were treated with radiotherapy with curative intent: 1.8 Gy per day, 5 fractions per week. Serial measurements of plasma TGF-β1, TNF--α and IL -6 were obtained in all patients before, weekly during radiotherapy and at each follow-up visits after completion of treatment. These measurements were quantified using enzyme linked immunosorbent assay (ELISA). All patients were evaluated for signs and symptoms of pneumonitis at each follow-up visits after completion of radiotherapy. High resolution CT (HRCT) scans were obtained when signs and symptoms of pneumonitis were developed after completion of radiotherapy. Thirteen patients eventually developed signs and symptoms of clinical pneumonitis while four patients did not. TGF- P 1 levels were elevated in - all 13 patients with pneumonitis, which showed characteristic pattern of elevation (38.45 ng/ml at pretreatment, 13.66 ng/ml during radiotherapy, then 60.63 ng/ml at 2-4 weeks after completion of radiotherapy). The levels of TNF--α and IL -6 were also elevated in the group of patients who developed pneumonitis but the pattern was not characteristic. Changes in plasma TGFβ-1 levels before, during and after radiotherapy appears to be a useful means by which to identify patients at risk for the development of symptomatic pneumonitis. Other cytokines like TNF--α and IL-6 shows no meaningful changes in association with radiation pneumonitis