Chen X, et al. - Researchers assessed progranulin, a pleiotropic glycosylated protein precursor that plays an important role in inflammation, as a circulating biomarker of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Participants were patients with AECOPD (n = 52), patients with stable COPD (n = 56) and healthy controls (n = 36). Higher plasma progranulin levels were observed in patients with AECOPD vs both stable COPD patients and healthy controls. Patients with AECOPD had significantly decreased plasma progranulin levels on the last day of hospitalization vs those on the first day of hospitalization. In multivariate logistic regression and ROC analysis, progranulin was identified as an independent predictor of AECOPD, with an area under the curve of 0.82. Overall, they concluded progranulin to be a possible valuable blood biomarker of AECOPD and to be implicated in the pathogenesis of AECOPD by disturbing inflammatory responses.