Drug-induced liver injury in hospitalized patients with notably elevated alanine aminotransferase

AIM： To identify the proportion, causes and the nature of drug-induced liver injury （DILI） in patients with no- tably elevated alanine aminotransferase （ALT）. METHODS： All the inpatients with ALT levels above 10 times upper limit of normal range （ULN） were ret- rospectively identified from a computerized clinical laboratory database at our hospital covering a 12-mo period. Relevant clinical information was obtained from medical records. Alternative causes of ALT eleva- tions were examined for each patient, including bili- ary abnormality, viral hepatitis, hemodynamic injury, malignancy, DILI or undetermined and other causes. All suspected DILI cases were causality assessed usingthe Council for International Organizations of Medical Sciences scale, and only the cases classified as highly probable, probable, or possible were diagnosed as DILI. Comments related to the diagnosis of DILI in the medical record and in the discharge letter for each case were also examined to evaluate DILI detection by the treating doctors. RESULTS： A total of 129 cases with ALT 〉 i0 ULN were identified. Hemodynamic injury （n = 46, 35.7%）, DILl （n = 25, 19.4%） and malignancy （n = 21, 16.3%） were the top three causes of liver injury. Peak ALT val- ues were lower in DILI patients than in patients with hemodynamic injury （14.5 5.6 ULN vs 32.5 ：I： 30.7 ULN, P = 0.001）. Among DILI patients, one （4%） case was classified as definite, 19 （76%） cases were clas- sified as probable and 5 （20%） as possible according to the ClOMS scale. A hepatocellular pattern was ob- served in 23 （92%） cases and mixed in 2 （8%）. The extent of severity of liver injury was mild in 21 （84%） patients and moderate in 4 （16%）. Before discharge, 10 （40%） patients were recovered and the other 15 （60%） were improved. The improved patients tended to have a higher peak ALT （808 ＋ 348 U/L vs 623 ＋ 118 U/L, P = 0.016） and shorter treatment duration before discharge （8 ＋ 6 d vs 28 ~ 12 d, P = 0.008） compared with the recovered patients. Twenty-two drugs and 6 herbs were found associated with DILl. Antibacterials were the most common agents causing DILI in 8 （32%） cases, followed by glucocorticoids in 6 （24%） cases. Twenty-four （96%） cases received treatment of DILl with at least one adjunctive drug. Agents for treatment of DILI included anti-inflammatory drugs （e.g., glycyr- rhizinate）, antioxidants （e.g., glutathione, ademetionine 1,4-butanedisulfonate and tiopronin）, polyene phospha- tidyl choline and herbal extracts （e.g., protoporphyrin disodium and silymarin）. Diagnosis of DILl was not mentioned in the discharge letter in 60% of the cases. Relative to prevalent cases and cases from wards of internal medicine, incident cases and cases from surgi- cal wards had a higher risk of missed diagnosis in dis- charge letter [odds ratio （OR） 32.7, 95%CI （2.8-374.1）,CONCLUSION： DILI is mostly caused by use of anti- bacterials and glucocorticoids, and constitutes about one fifth of hospitalized patients with ALT 〉 10 ULN. DILI is underdiagnosed frequently.