Epidemiology and outcomes of alpha-1 antitrypsin deficiency in Sweden 2002-2020: A population-based cohort study of 2286 individuals.

Objective: To estimate the incidence, prevalence, and outcomes of patients with diagnosed alpha-1-antitrypsin deficiency (AATD) in Sweden, 2002-2020.

Study Design And Setting: The Swedish National Patient Registry was utilized to identify patients with a first diagnosis of AATD between 2002 and 2020. Each patient was matched with up to 10 comparators from the general population. AATD incidence and prevalence were estimated. Causes of death and rates of mortality, transplantation, lung disease, liver cirrhosis, and previous neonatal cholestasis were estimated.

Results: The incidence rate of AATD was 1.83 (95% confidence interval [CI] 1.58-2.11) per 100,000 person-years and the total prevalence was 21.04 (95%CI = 20.17-21.94) per 100,000 persons at the end of 2020. Mortality was 3.55 times higher (95%CI = 3.15-3.99) for patients with AATD. Rates of liver-(hazard ratio [HR] = 22.95, 95%CI = 12.61-41.75), lung-(HR = 12.09, 95%CI = 8.87-16.47), and cardiovascular (HR = 1.90, 95%CI = 1.45-2.90) related death were higher in patients with AATD. The cumulative incidence after 10 years of follow-up was 1.69% (95%CI = 1.15-2.41) for liver transplantation and 4.14% (95%CI = 3.20-5.26) for lung transplantation. About 20% of patients were estimated to be alive without lung disease or liver cirrhosis 20 years after an AATD diagnosis. Neonatal cholestasis codes were found in 3.0% of AATD patients and 0.5% of comparators (odds ratio 6.28, 95%CI = 3.81-10.36).

Conclusions: In this population-based cohort study on AATD in Sweden, an increasing incidence was observed, and significantly higher rates of death from liver, lung, and cardiovascular causes compared to the general population were found. Only a minority of diagnosed AATD patients were estimated to be free of liver cirrhosis and lung disease after 20 years.