Clinical and pathological features of antinuclear antibody-positive drug-induced liver injury compared with autoimmune hepatitis: A retrospective study

Drug-induced liver injury (DILI) and autoimmune hepatitis (AIH) often present with overlapping clinical and pathological features, which makes the differential diagnosis particularly challenging in antinuclear antibody-positive (ANA-positive) cases. This study aims to provide new insights into addressing this diagnostic challenge and improving the distinction between ANA-positive DILI and AIH. A total of 87 DILI and 82 AIH cases who underwent liver biopsy at The First Affiliated Hospital of Nanchang University between January 2013 and December 2023 were enrolled. Among them, 42 cases were ANA-positive DILI. A retrospective observational study was conducted on the above patients. We observed that the detection rate of antinuclear antibodies was significantly higher in female patients. Compared to the AIH group, the ANA-positive DILI group exhibited lower levels of the S index, serum globulin, activated partial thromboplastin time, immunoglobulin G, immunoglobulin A, and immunoglobulin M, while presenting higher levels of total bilirubin and blood platelets (all P <.05). Both the DILI and AIH groups predominantly exhibited ANA positivity. Notably, the anti-smooth muscle antibody positivity rate was significantly higher in the AIH group compared to the ANA-positive DILI group. The AIH group exhibited more severe liver inflammation and fibrosis compared to the ANA-positive DILI group. Neutrophil infiltration was predominant in the ANA-positive DILI group, whereas lymphocytic and plasma cell infiltration was more pronounced in the AIH group. When DILI patients tested positive for antinuclear antibodies, significant differences in liver function, complete blood count, immunoglobulin levels, and liver histopathological characteristics remained between them and AIH patients. For cases in which a definitive diagnosis is difficult, early liver biopsy and long-term follow-up are recommended to monitor disease progression.