Prevalence and clinical characteristics of alpha-1 antitrypsin deficiency in liver explants in a Mexican cohort

•α1 antitrypsin deficiency is an unrecognized cause of liver disease.•α1 antitrypsin deficiency was found unexpectedly in 4.5% of liver explants.•Heterozygous variants were found in all patients with α1 antitrypsin deficiency.•Coexistent α1 antitrypsin deficiency/fatty liver raises the risk of liver fibrosis. Alpha-1 antitrypsin deficiency (AATD) is a risk factor for liver disease. PASD-positive inclusions have been found unexpectedly in approximately 10% of liver explants in patients with no previous diagnosis of AATD, particularly, in patients with non-alcoholic steatohepatitis (NASH), supporting a synergistic mechanism of liver injury between AATD and environmental factors. We aimed to determine the clinical characteristics of mestizo patients in which AATD was diagnosed before or after liver transplantation. Liver explants of patients with cryptogenic, alcoholic, and NAFLD/NASH cirrhosis undergoing orthotopic liver transplantation (OLT) were included. Liver histopathology was assessed by two expert pathologists. Hematoxylin and eosin staining, PASD staining, and confirmatory AAT immunohistochemistry were performed. In explants with positive histopathology, genotyping for SERPINA1 was performed. A total of 180 liver transplants were performed during the study period. Of these, 44 patients with cryptogenic cirrhosis, NASH, and alcoholic cirrhosis were included. Of these patients, two liver explants (4.5%) had PASD-positive inclusions stain and confirmatory immunochemistry. During the period evaluated, another two patients with a diagnosis of AATD before the OLT were also included. The four patients had overweight or obesity, three had type 2 diabetes mellitus, and two developed liver steatosis after the OLT. AATD was found to be an infrequent finding in patients with cryptogenic, NASH/NAFLD, and alcoholic cirrhosis in our population. However, it is important to consider this entity as it may represent an additional factor in the appearance and progression of liver fibrosis in patients with metabolic syndrome.