Longitudinal Evaluation of Individuals With Severe Alpha-1 Antitrypsin Deficiency (Pi∗ZZ Genotype)

Abstract

Background & Aims: Homozygous Pi∗Z mutation in alpha-1 antitrypsin (Pi∗ZZ genotype) predisposes to pulmonary loss-of-function and hepatic gain-of-function injury. To facilitate selection into clinical trials typically targeting only 1 organ, we systematically evaluated an international, multicenter, longitudinal, Pi∗ZZ cohort to uncover natural disease course and surrogates for future liver- and lung-related endpoints. Methods: Cohort 1 recruited 737 Pi∗ZZ individuals from 25 different centers without known liver comorbidities who received a baseline clinical and laboratory assessment as well as liver stiffness measurement (LSM). A follow-up interview was performed after at least 6 months. Cohort 2 consisted of 135 Pi∗ZZ subjects without significant liver fibrosis, who received a standardized baseline and follow-up examination at least 2 years later, both including LSM. Results: During 2634 patient-years of follow-up, 39 individuals died, with liver and lung being responsible for 46% and 36% of deaths, respectively. Forty-one Pi∗ZZ subjects who developed a hepatic endpoint presented with significantly higher baseline liver fibrosis surrogates, that is, LSM (24 vs 5 kPa, P < .001) and aspartate aminotransferase–to-platelet ratio index (1.1 vs 0.3 units, P