摘要:Background Today few studies have focused on using calprotectin as an effective biomarker for monitoring the exacerbation of pulmonary complications in cystic fibrosis (CF). Thus, the present study aimed to assess the diagnostic value of the changes in the calprotectin level of patient's serum and sputum during responding to the therapy of exacerbated CF in children. Materials and Methods: The cross-sectional study was conducted among 21 CF patients, which received required supportive and therapeutic procedures based on the protocol related to pulmonology ward in the Children Medical Research and Training Center of Tabriz University of Medical Sciences. The sputum and serum samples of all patients were collected to evaluate calprotectin level at 1-2 days after starting therapy with routine antibiotics such as cephalosporin and macrolides, and they were again gathered at the end of therapy process. Results: Assessing outcome in 21 patients under study represented complete and partial recovery in 12 (57.2%), and 9 (42.8%) ones, respectively. The mean decrease in calprotectin level in the serum and sputum of the patients was respectively obtained as 40.72 89.08 μg/ml and 99.03 225.94 μg/ml. The calprotectin decrease in serum with the cutoff point of 15.70 μg/ml possessed the sensitivity of 66.7% and specificity of 55.6% in predicting complete recovery outcome; while that of sputum with the cutoff point of 26.20 μg/ml had the sensitivity and specificity of 66.7 and 22.2%, respectively. Conclusion The mean age of participants were 8.61±4.19 years. It can be concluded that serum and sputum calprotectin decrease with cutoff point of 15.70 μg/ml and 26.20 μg/ml, respectively in have high sensitivity for determining response to treatment in cystic fibrosis exacerbation.