There is limited information about blood biomarkers in AATD. Therefore the aim of our study was to identify the possible associations between serum biomarkers and the severity of lung disease.

Retrospective study performed from the database of EARCO (European Alpha-1 Research Collaboration) International registry of patients with AATD Pi*ZZ.  Serum biomarkers and forced expiratory volume in the first second (FEV1) were collected. Neutrophil/lymphocyte ratio (NLR), eosinophil/lymphocyte ratio (ELR) and platelet/lymphocyte ratio (PLR) were calculated. Data were analyzed to establish possible associations between biomarkers and lung function and clinical phenotypes.

A total of 861 Pi*ZZ patients were included. 50% were men with a mean age of 55.5 (13.5) years. 57.3% were former smokers with a mean FEV1% of 67.3 (30.5) %.  We observed significant associations between FEV1% and GGT, hemoglobin, leucocytes, neutrophils and NLR (p<0.05 for all). Patients with emphysema presented significantly higher levels of GGT, FIB-4, hemoglobin, leucocytes, neutrophils (%) and NLR. Patients with bronchiectasis had higher levels of liver enzymes, FIB-4 and hemoglobin. In asthma patients, we observed higher concentrations of FIB-4 and platelets (p<0.05).

Several biomarkers were associated with the severity of FEV1% impairment. Different phenotypes of respiratory disease were associated with elevated levels of different biomarkers. The predictive value of these biomarkers must be confirmed in prospective studies.