CYTOKINE CONCENTRATIONS IN SPUTUM FROM PATIENTS WITH CYSTIC-FIBROSIS AND THEIR RELATION TO EOSINOPHIL ACTIVITY

To evaluate whether concentrations of cytokines supposed to be involve d in eosinophil recruitment and activation were elevated in cystic fib rosis (CF), we assessed interleukin-3 (IL-3), IL-5, IL-8, regulated on activation, normal T-cell expressed and secreted (RANTES); and granul ocyte-macrophage colony stimulating factor (GM-CSF) in sputa from 32 p atients with CF, eight patients with atopic bronchial asthma, and six patients with bacterial pneumonia. In addition, eosinophil cationic pr otein (ECP) and eosinophil protein X (EPX) were measured as markers of eosinophil activation. In patients with CF, sputum levels of IL-8 wer e elevated (p < 0.01) as compared with asthmatic patients. Concentrati ons of IL-3, ECP, and EPX were not different in the two groups. Howeve r, IL-5 (p < 0.0001), RANTES (p < 0.003), and GM-CSF (p < 0.0001) were significantly lower in the CF group than in subjects with asthma. IL- 5 was detected only in sputum samples from CF patients with Aspergillo s sensitization. In patients with pneumonia, IL-8 levels only were inc reased. In CF sputum, ECP levels were significantly correlated with th e levels of IL-8 (r = 0.626, p < 0.0001) and IL-3 (r = 0.642; p < 0.00 01), whereas in asthmatic patients IL-5, IL-8, and RANTES concentratio ns were significantly related to ECP in sputum. These findings suggest that different cytokine profiles are responsible for eosinophil activ ation in patients with CF as compared with asthmatic patients. In CF, IL-8 and IL-3 appear to be responsible for increased degranulation of eosinophils.