Diagnostic and prognostic values of Club cell protein 16 (CC16) in critical care patients with acute respiratory distress syndrome

BACKGROUND Acute respiratory distress syndrome (ARDS) is a critical condition characterized by bilateral pulmonary infiltrates and severe hypoxemia. This study aimed to evaluate the diagnostic and prognostic values of Club cell protein 16 (CC16) in critical care patients with ARDS. METHODS In this retrospective observational study, 83 patients with ARDS and 129 non-ARDS patients on ICU admission were enrolled. The differences in serum CC16 and other laboratory indicators between two groups were analyzed. The sensitivity, specificity, positive and negative predictive values, and accuracy of CC16 as a diagnostic marker on ICU admission were determined by receiver operating characteristic (ROC) curve analysis. The correlation between serum CC16 levels and the severity of ARDS as quantified by PaO2 /FiO2 ratio were further assessed. CC16 levels were compared between survivors and non-survivors. The relationships between CC16 levels and duration of ICU and hospitalization were evaluated. RESULTS The serum CC16 levels in ARDS patients were significantly higher than that in non-ARDS patients (54.44±19.62 vs 24.13±12.32 ng/mL, P=.001). ROC analysis showed that the sensitivity, specificity, positive predictive value, and negative predictive value were 90.4%, 79.8%, 74.2%, and 92.8%, respectively, when the cut-off value was set at 33.3 ng/mL. CC16 levels were correlated with the severity of ARDS. The serum CC16 levels were significantly greater in non-survivors than in survivors from the ARDS group. CC16 levels were associated with ICU stay but not hospital stay. CONCLUSIONS CC16 may serve as a diagnostic and stratification marker for ARDS. However, it provided limited prognostic information for ARDS.