Validation of Clara Cell Protein as a Novel Diagnostic Biomarker for the Differentiation of Cardiogenic Pulmonary Edema From Non-Cardiogenic Pulmonary Edema

Club cells or Clara cells (CCs) were first described in 1881 but their importance was forgotten until Max Clara's 1937 study identifying these bronchiolar exocrine cells. CCs constitute up to 44% of proliferating small airway cells, functioning as epithelial progenitors during lung regeneration and repair of injury.

CC16 can be useful in distinguishing between cardiogenic pulmonary edema (CPE), caused by increased pressure in the heart's left ventricle, and non-cardiogenic pulmonary edema, such as acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), which are not related to heart failure. Patients with ALI/ARDS tend to have lower levels of CC16 in their plasma and pulmonary edema fluid compared to those with CPE, suggesting a potential diagnostic role for CC16 in these conditions.