Severe vitamin D deficiency is a prognostic biomarker in autoimmune hepatitis

Background Vitamin D deficiency has been implicated in the outcome of chronic liver disease. Aim To determine the frequency of severe vitamin D deficiency in autoimmune hepatitis (AIH), assess its association with treatment non-response, and evaluate the relationship between vitamin D status and liver-related mortality and need for transplantation. Methods Two hundred and nine patients were evaluated by liver tissue examination at presentation. Serum vitamin D levels were determined, and serum levels <25 nmol/L (10 ng/mL) were considered severely deficient. Treatment non-response was defined as non-normalised aspartate aminotransferase/alanine aminotransferase and immunoglobulin G levels during conventional immunosuppressive therapy. Univariate and multivariate analyses were performed using binary logistic regression and Cox proportional hazards model. Results The mean vitamin D level was 60 +/- 38 nmol/L (range, 3-263 nmol/L), and 42 patients (20%) had severe vitamin D deficiency. Treatment non-response was more common in patients with severe vitamin D deficiency than in patients without (59% vs 41%, P = 0.04). Severe vitamin D deficiency was also independently associated with a higher risk of developing cirrhosis (HR 3.40; 95% CI 1.30-8.87, P = 0.01) and liver-related mortality or requirement for liver transplantation (LT; HR 5.26, 95% CI, 1.54-18.0, P = 0.008). Patients with persistent severe deficiency following vitamin D supplementation continued to have poor outcomes. Conclusions Severe vitamin D deficiency is associated with treatment non-response, progression to cirrhosis, and liver-related death or need for LT. Severe vitamin D deficiency is a prognostic biomarker in AIH.