Manon-Jensen T, Langholm LL, Rønnow SR, et al. - In view of the fact that plasma fibrinogen affords the only FDA approved biomarker for the prediction of death and COPD exacerbations in COPD cases, researchers investigated if the additional characterization of disease phenotype and COPD progression can be offered by alterations in the processing of fibrinogen. They used The Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) cohort to select a subpopulation of people with COPD, (n = 983) smoker (n = 205) and non-smoker controls (n = 98). Measurements were obtained for two biomarkers that particularly target the thrombin-mediated transformation of fibrinogen into fibrin (PRO-FIB), and plasmin-mediated degradation of cross-linked fibrin (X–FIB), and comparison with fibrinogen measurements was performed. Two-year mortality was predicted by X–FIB, with an adjusted hazard ratio of 1.48 per SD, this was comparable to the fibrinogen hazard ratio of 1.59 per SD. Symptomatic COPD (mMRC ≥ 2) vs asymptomatic COPD was characterized by significantly elevated X–FIB, fibrinogen and PRO-FIB. The link of X–FIB with emphysema and of plasma fibrinogen with exacerbations was observed. The requirement for biomarkers to characterize the heterogeneity of COPD was highlighted. Different aspects of COPD can be better understood with the help of information offered by each of the three fibrinogen biomarkers examined, such knowledge may help characterize disease endotypes and to evaluate death risk in COPD.