A prospective study on the causes of notably raised alanine aminotransferase (ALT).

Objective: High levels of alanine aminotransferase (ALT) can be a marker of severe liver disease with variable aetiologies and prognosis. Very few prospective studies have been undertaken on the aetiology and prognosis of patients with high ALT levels. No population-based prospective study has systematically evaluated drug-induced liver injury (DILI) among these patients. The objective was to determine the aetiology and prognosis of patients with high ALT.

Materials And Methods: In a catchment area of 160,000 inhabitants, a population-based prospective study identified all adult patients with serum level of ALT >500 U/L during a 12-month period. All underwent thorough diagnostic work-up and follow-up. In suspected DILI, causality was assessed with Roussel Uclaf Causality Assessment Method.

Results: A total of 155 patients were identified with ALT >500 U/L, 12 children and one with ALT of non-liver-related origin, leaving 142 patients for the analysis: 73 (51%) males, median age 52 (IQR 36-68, range 19-89 years). The most common causes were choledocholithiasis 48/142 (34%), ischaemic hepatitis 26 (18%), viral hepatitis 16 (11%) and DILI 15 (11%), hepatobiliary malignancy (n = 6), surgery/interventions (n = 8) and other aetiologies (n = 23). No specific aetiology was found in 6% of cases. In the total study cohort 99 (70%) required hospitalisation, 78 (55%) had jaundice and 22 (16%) died, liver-related death in 10%, 35% in IH and 7% in DILI.

Conclusions: The most common cause of notably high ALT was choledocholithiasis. Ischaemic hepatitis was a common aetiology with approximately 35% liver-related mortality. Viral hepatitis and DILI were important aetiologies among these patients.