RESUMO
BACKGROUND AND AIMS: Alpha-1 antitrypsin deficiency is an inherited disorder caused by alpha-1 antitrypsin (AAT) mutations. We analysed the association between alcohol intake and liver-related parameters in individuals with the heterozygous/homozygous Pi*Z AAT variant (Pi*MZ/Pi*ZZ genotype) found in the United Kingdom Biobank and the European Alpha1 liver consortium. METHODS: Reported alcohol consumption was evaluated in two cohorts: (i) the community-based United Kingdom Biobank (17 145 Pi*MZ, 141 Pi*ZZ subjects, and 425 002 non-carriers [Pi*MM]); and (ii) the European Alpha1 liver consortium (561 Pi*ZZ individuals). Cohort (ii) included measurements of carbohydrate-deficient transferrin (CDT). RESULTS: In both cohorts, no/low alcohol intake was reported by >80% of individuals, while harmful consumption was rare (~1%). Among Pi*MM and Pi*MZ individuals from cohort (i), moderate alcohol consumption resulted in a <30% increased rate of elevated transaminases and ~50% increase in elevated gamma-glutamyl transferase values, while harmful alcohol intake led to an at least twofold increase in the abnormal levels. In Pi*ZZ individuals from both cohorts, moderate alcohol consumption had no marked impact on serum transaminase levels. Among Pi*ZZ subjects from cohort (ii) who reported no/low alcohol consumption, those with increased CDT levels more often had signs of advanced liver disease. CONCLUSIONS: Pi*MZ/Pi*ZZ genotype does not seem to markedly aggravate the hepatic toxicity of moderate alcohol consumption. CDT values might be helpful to detect alcohol consumption in those with advanced fibrosis. More data are needed to evaluate the impact of harmful alcohol consumption.
RESUMO
BACKGROUND: Circulating polymerized mutant Z-alpha-1 antitrypsin (Z-polymer) constitutes a characteristic feature in alpha-1 antitrypsin deficiency (AATD), but there is limited knowledge about its association with adverse clinical outcomes and liver fibrosis. We explored this association using data from a large cohort of adults with AATD. METHODS: A total of 836 (431 PiZZ, 405 PiMZ) adults with AATD and 312 controls (PiMM) from the European Alpha-1 Liver Cohort (2015-2020) were included. Time-to-event analyses were conducted for adults with the PiZZ genotype followed for adverse clinical outcomes (earliest occurrence of liver-related hospitalization, liver transplant or all-cause mortality). Cox proportional hazard models were used to describe the association between binary circulating Z-polymer levels and adverse clinical outcomes. Correlations between baseline circulating Z-polymer levels and baseline liver fibrosis (liver stiffness measurement [LSM] determined by transient elastography [FibroScan®]) were evaluated. The analyses were stratified by augmentation therapy status. RESULTS: Of 324 adults with the PiZZ genotype and longitudinal follow-up data, 28 reported adverse clinical outcomes. Higher baseline circulating Z-polymer levels were associated with an increased risk of adverse clinical outcomes in both crude (hazard ratio [95% confidence interval, CI], 2.88 [1.21, 6.87]) and age-adjusted (1.96 [0.78, 4.94]) analyses. In adults with the PiZZ genotype, circulating Z-polymer levels were weakly positively correlated with baseline LSM (Spearman's rho [95% CI]: 0.21 [0.11, 0.31]). Similar results were observed after stratification by augmentation therapy status. CONCLUSIONS: In adults with the PiZZ genotype, higher circulating Z-polymer levels were associated with a shorter time to adverse clinical outcome, and positively correlated with baseline LSM. Circulating Z-polymer levels may be a prognostic biomarker of clinically relevant disease in AATD.