Alpha-1 Antitrypsin PiMZ Heterozygosity in the Setting of Alcohol-Associated Cirrhosis: A Case Report.

Alpha-1 antitrypsin deficiency (AATD) is classically associated with the PiZZ genotype, while PiMZ heterozygosity has historically been considered a benign carrier state. Emerging evidence, however, suggests PiMZ status functions as a clinically significant cofactor for liver fibrosis when combined with metabolic or environmental stressors such as alcohol use. We present the case of a 57-year-old woman with a diagnosis of cirrhosis of unclear etiology and a remote history of alcohol use, who was admitted with jaundice and profound hyponatremia. Workup for viral, autoimmune, and hereditary hemochromatosis etiologies was unrevealing. Transjugular liver biopsy demonstrated periodic acid-Schiff-positive, diastase-resistant (PAS-D) intrahepatocytic globules with mild siderosis; subsequent testing revealed a low serum alpha-1 antitrypsin (A1AT) level and PiMZ genotype. This case illustrates the diagnostic value of liver biopsy in identifying AATD-pattern globules and prompting confirmatory serum and genotypic testing. Although this patient's serum AAT was notably reduced - a diagnostically helpful but not universal finding, as many PiMZ carriers have levels near the normal range - the case underscores that biopsy and genotyping remain essential for diagnosis regardless of serum AAT level. It further reflects the growing recognition that PiMZ heterozygosity, particularly in the presence of alcohol exposure, may meaningfully contribute to progression toward decompensated cirrhosis.