BACKGROUND: Alpha1 anti-trypsin (α1-AT), a serine protease inhibitor synthesized in the liver, is a major circulating antiprotease that provides defense against proteolytic damage in several tissues. Its deficiency is associated with airflow obstruction. The present study aimed to explore the role of α1-AT as a biomarker of airflow performance in chronic liver disease (CLD).

MATERIAL AND METHODS: Serum α1-AT levels and lung function (spirometry) were evaluated in non-primary α1-AT-deficient, alcoholic CLD patients without evident respiratory limitations.

RESULTS: Thirty-four patients with airflow obstruction (n=11), airflow restriction (n=12), and normal airflow (n=11, age-matched controls) were eligible. α1-AT was decreased in the airflow obstruction group. ROC-cutoff α1-AT=24 mg/dL effectively discriminated airflow obstruction (AUC=0.687) and was associated with a 10-fold higher risk (p=0.0007).

CONCLUSIONS: Lower α1-AT increased the risk of airflow obstruction in CLD patients without primary α1-AT deficiency.

Keywords: Biomarkers - blood, Case-Control Studies, Cross-Sectional Studies, Liver Diseases, Alcoholic - physiopathology, Lung Diseases, Obstructive - physiopathology, Pulmonary Disease, Chronic Obstructive - physiopathology, Risk Factors, Spirometry, alpha 1-Antitrypsin - blood, alpha 1-Antitrypsin Deficiency - physiopathology