Risk of infections and their role on subsequent mortality in biopsy-proven alcohol-related liver disease

Background and aims: The risk for infection in alcohol-related liver disease (ALD) has rarely been investigated at a population level, nor if the underlying liver histopathology is associated with infection risk. We examined the rate of hospital-based infections in a nationwide cohort of biopsy-proven ALD, and the subsequent risk of death.

Methods: Population-based cohort study in Sweden comparing 4028 individuals with an international classification of disease (ICD) code for ALD and a liver biopsy from 1969 to 2017 with 19,296 matched general population individuals. Swedish national registers were used to ascertain incident infections in secondary or tertiary care and subsequent mortality until 2019. We used Cox regression, adjusted for sex, age, education, country of birth, diabetes, and number of hospitalizations in the year preceding liver biopsy date, to estimate hazard ratios (HRs) in ALD and histopathological subgroups compared to reference individuals.

Results: Median age at ALD diagnosis was 59 years, 65% were men and 59% had cirrhosis at baseline. Infections were more common in patients with ALD (84 cases/1000 person-years [PY]) compared to reference individuals (29/1000 PYs; adjusted hazard ratio [aHR] 3.06, 95% CI = 2.85-3.29). This excess risk corresponded to one additional infection per 18 ALD patients each year. The rate of infections was particularly high in individuals with cirrhosis (aHR = 3.46) and in those with decompensation (aHR = 5.20). Restricting our data to those with an infection, ALD (aHR = 3.63, 95%CI = 3.36-3.93), and especially ALD cirrhosis (aHR = 4.31, 95%CI = 3.89-4.78) were linked to subsequent death.

Conclusions: Individuals with biopsy-proven ALD have a three-fold increased rate of infections compared with the general population. The risk of death after an infection is also considerably higher in individuals with ALD.