Drug‐induced liver injury (DILI) ascribed to non‐steroidal anti‐inflammatory drugs (NSAIDs) in the USA—Update with genetic correlations

Objective To describe patients with NSAID‐DILI, including genetic factors associated with idiosyncratic DILI. Methods In DILIN, subjects with presumed DILI are enrolled and followed for at least 6 months. Causality is adjudicated by a Delphic approach. HLA sequencing of multiethnic NSAID‐DILI patients and HLA allele imputation of matching population controls were performed following overall, class and drug‐based association analysis. Significant results were tested in a non‐Hispanic White (NHW) case–control replication cohort. Results Between September 2004 and March 2022, causality was adjudicated in 2498, and 55 (41 [75%] women) were assessed as likely due to NSAIDs. Median age at onset was 55 y (range 22–83 y). Diclofenac was the causative drug in 29, celecoxib in 7, ibuprofen in 5, etodolac and meloxicam each in 4. Except for meloxicam and oxaprozin (n = 2), the liver injury was hepatocellular with median R 15–25. HLA‐DRB1*04:03 and HLA‐B*35:03 were significantly more frequent in NSAID‐DILI patients than in non‐NSAID DILI controls. Interestingly, 85% of the HLA‐DRB1*04:03 carriers developed DILI due to the use of acetic acid derivative NSAIDs, supporting the hypothesis that HLA‐DRB1*04:03 could be a drug and/or class risk factor. HLA‐B*35:03 but not HLA‐DRB1*04:03 association was confirmed in the independent NHW replication cohort, which was largely driven by diclofenac. Conclusions Despite prevalent use, NSAID‐DILI is infrequent in the United States. Diclofenac is the most commonly implicated, and adherence to warnings of risk and close observation are recommended. The increased frequency of HLA‐B*35:03 and DRB1*04:03, driven by diclofenac, suggests the importance of immune‐mediated responses.