SERPINA1 and pyogenic liver abscess: Disease progression, infection (e.g., bacterial cholangitis, pyogenic liver abscess), obstruction (malignant or non-malignant aetiology such as gallstone disease), primary biliary cirrhosis, primary sclerosing cholangitis, alpha-1 antitrypsin deficiency, IgG4 disease, bile duct stricture, thromboembolic disease, secondary cholangitis, alcohol use, other systemic illnesses or infections, other causes of drug induced liver injury.