Currently, research on biopsy-proven acute drug-induced liver injury (DILI) remains limited. This study aimed to identify clinical characteristics and risk factors for significant hepatic inflammation in patients with acute DILI.

An ambispective cohort study was conducted on biopsy-proven acute DILI patients admitted to our hospital from 2012 to 2018. Using the Scheuer scoring system, patients were categorized into G0-2 or G3-4 groups and followed up for 12 months after first admission. Clinical characteristics and outcomes were retrieved from medical records.

The median age of the 157 enrolled patients (65.6% female) was 40.4 (interquartile range (IQR), 31.9–49.1) years. The median latency and length of hospitalization were 30.0 (IQR, 5.0–60.0) and 18.0 (IQR, 12.0–26.0) days. The proportions of patients in the G0-2 and G3-4 groups were 54.8% and 45.2%, respectively. Logistic regression analysis revealed that females (odds ratio (OR): 2.623, 95% confidence interval (CI): 1.169–5.887, p = 0.019), higher body mass index (OR: 1.168, 95% CI: 1.029–1.325, p = 0.016), higher total bilirubin (OR: 1.004, 95% CI: 1.000–1.007, p = 0.047), and lower prothrombin activity (OR: 0.976, 95% CI: 0,957–0.995, p = 0.013) were associated with significant hepatic inflammation. The predominance of the hepatocellular injury pattern (60.5%) at admission transformed into a predominance of the cholestatic pattern (60.5%) at discharge. During follow-up, 23 patients (14.6%) developed chronic DILI, with nine patients (5.7%) progressing to cirrhosis. Moreover, 15 female patients (9.6%) developed autoimmunity (3cases in the G0-2 group vs 12 cases in the G3-4 group, p < 0.05).

Acute DILI patients with high-risk factors were more likely to develop significant hepatic inflammation, and females with significant inflammation were at a higher risk of developing autoimmunity during follow-up.