Troxis necrosis, a novel mechanism for drug-induced hepatitis secondary to immunomodulatory therapy

Abstract

Objectives: A case of drug-induced hepatitis mediated by troxis necrosis, a form of autoimmune hepatitis, is described.

Methods: Clinical data, light and electron microscopy of an ultrasound-guided core needle liver biopsy specimen, were examined to investigate the cause of transaminitis in a 26year old male patient on Cellcept and Plaquenil for the treatment of lupus erythematosus. A systematic PUBMED review of troxis necrosis as the underlying mechanism for drug-induced hepatitis was performed.

Results: Liver function tests (LFTs) were significant for elevated AST (305) and ALT (174); the autoimmune workup was significant for anti-ANA positivity and α-SMA negativity. On light microscopy, the liver biopsy shows focal areas of lymphocytic infiltrates surrounding and forming immunologic synapses with lobular hepatocytes, indicating lobular hepatitis of autoimmune nature. Electron microscopy confirmed the presence of immunologic synapses. Upon cessation of the offending medications, the LFTs returned to baseline with no further intervention. Literature search yielded 7 previously reported cases of drug-induced hepatitis mediated by troxis necrosis.

Conclusion: Troxis necrosis is a novel mechanism for drug-induced hepatitis, including immunomodulatory medications including a monoclonal anti-TWEAK antibody and Cellcept and Plaquenil, two widely used immunosuppression/anti-rejection medications.

Keywords: Drug induced hepatitis; Immunologic synapse; Troxis necrosis.