GPT and Autoimmunity: For this reason, the American College of Gastroenterology clinical guidelines strongly recommend that all patients with abnormal aspartate aminotransferase (AST) and alanine transaminase (ALT) levels, and particularly patients with autoimmune conditions, should be screened for autoimmune hepatitis (AIH) with anti-nuclear antibody (ANA), anti-smooth muscle antibody (SMA), and globulin level tests (IgG) [10].