Jung D, Dong K, Jang J, et al. - Since the underdiagnosis of cystic fibrosis (CF) pulmonary exacerbations (PEx) by CF clinicians has been reported and serum C-reactive protein (CRP) and calprotectin represent inflammatory biomarkers that hold the potential to assist in the diagnosis of PEx, researchers examined the diagnostic performance of absolute as well as fold-change CRP and calprotectin cut-offs to distinguish stable and PEx visits in this study with 19 participants (56 stable, 46 PEx visits) from a longitudinal study. To detect PEx, optimal absolute and fold-change thresholds, based on Youden's index, were identified to be 9.5 mg/L and 2.2-fold for CRP and 8.1 mg/L and 1.3-fold for calprotectin. Improved diagnostic performance was achieved with a step-wise algorithm. Findings revealed the good performance of CRP and calprotectin in discriminating stable vs PEx visits and these seemed to hold promise for use as diagnostic biomarkers but these diagnostic thresholds can not be implemented until further validation studies are not performed.