Introduction There are many potential causes for an ALT>1000 IU/L, the commonest being ischaemia, drug induced liver injury (DILI) and viral hepatitis. There are however many other potential causes, and, more recently, acute endemic hepatitis E (HEV) has been identified in some of these patients.

Aims/Background Our aim was to establish the causes of ALT>1000 IU/L in patients in a large teaching hospital. We also wanted to determine the number of patients in whom a cause was not found, and how many of these had been checked for HEV.

Method All ALT values over a two-year period (2010/11) were examined. Those with an ALT>1000 IU/L were identified and their investigations/notes reviewed. All data was annonymised and recorded in a dedicated electronic database.

Results 182 patients (57% male and 43% female) with an ALT>1000 IU/L were identified. The mean age for males versus females was 47+/−18 years versus 62+/−18 years (p=0.001). The most common causes of an ALT>1000 IU/L were ischaemic hepatitis, (n=111, (61%)), DILI, (n=30, (16.5%)) and viral hepatitis, (n=22, (12.1%)). The remaining causes included choledocholithiasis (n=8) and autoimmune hepatitis (n=3). No cause was identified for 8 patients. Of these, none had HEV IgM checked. 35.7% (n=65) died during this admission, 54.9%(n=100) were discharged home and 9.3% (17) were not admitted.

Conclusion This review confirms that ischaemic liver injury is the commonest cause of ALT>1000 IU/L in hospital inpatients. Ischaemia, DILI and viral hepatitis account for almost 90% of presentations. Only 5% of patients had no aetiology identified. This number may be significantly lower if all had had HEV IgM checked.