PTX3 and chronic obstructive pulmonary disease: Furthermore, it has been suggested that plasma PTX3 levels could act as a biomarker in various lung diseases, such as lung carcinoma43, chronic obstructive pulmonary disease (COPD)48, and acute lung injury (ALI)49, while sputum PTX3 levels represent a candidate biomarker for the evaluation of airway inflammation and remodeling in children with asthma50.