INTRODUCTION: Unexplained abnormal liver function tests in a patient are a common reason for referral to a hepatologist. Patients may often have coexisting liver diseases, and require a liver biopsy for definitive diagnosis to guide treatment. We present a patient with celiac disease, fatty liver disease, and a delayed diagnosis of autoimmune hepatitis, highlighting the need to recognize anchoring bias. CASE DESCRIPTION/METHODS: A 55 year-old male, with a history of eosinophilic esophagitis and obesity, was referred a hepatologist for elevated liver enzymes. The patient was asymptomatic and consumed two units of alcohol per week. His BMI was 30, and he did not have stigmata of chronic liver disease and hepatomegaly. Labs showed total bilirubin 2.0mg/dL, ALP 59U/L, AST 132U/L, ALT 392U/L, albumin 4.3g/dL, and INR 1.3. Complete serologic evaluation for secondary causes of liver disease including viral hepatitis and autoimmune screen, alpha 1 antitrypsin, iron studies and ceruloplasmin were negative. Tissue transglutaminase (tTG) antibody was greater than 150U/mL and EGD revealed Modified-Marsh 3 pathologic changes suggestive of celiac disease. Liver ultrasound showed steatosis without cirrhosis and transient hepatic elastography suggested mild fibrosis (6.7kPa). Transaminases and tissue tTG antibody increased to more than 10 times the upper limit of normal despite adherence to a gluten-free diet. Liver biopsy confirmed evidence of autoimmune hepatitis with mild fibrosis and steatosis. The patient was commenced on immunosuppression with significant improvement in liver function tests. DISCUSSION: Liver involvement in celiac disease accounts for 9% of patients with unexplained, mildly elevated transaminases and has the potential to impact the clinical course of established liver disease. Primary biliary cholangitis and autoimmune hepatitis are also associated with celiac disease. Due to the high prevalence of elevated liver enzymes in celiac disease, it is reasonable to delay liver biopsy and monitor for improvement of liver enzymes with exclusion of dietary gluten. A liver biopsy to rule out coexisting liver diseases is warranted in patients with celiac disease with severely elevated transaminases or failure to respond to a gluten free diet. Clinicians must maintain a high index of suspicion for concurrent autoimmune liver disease especially in patients with a history of other autoimmune diseases. 1) Rubio-Tapia, A., Murray, JA. Liver involvement in celiac disease. Minerva Medica, 2008 Dec; 99(6): 595–604.