Azathioprine-induced Veno-occlusive Hepatotoxicity in a Patient with Myasthenia Gravis.

Introduction: Myasthenia gravis (MG) is an autoimmune disorder of post-synaptic neuromuscular junction characterised by fatigable muscle weakness and is treated with prednisolone with or without other immunosuppressants, including azathioprine (AZA). Veno-occlusive hepatotoxicity of AZA is a rare complication in MG.

Case report: We report a 35-year-old man with MG who was treated with pyridostigmine, prednisolone, and AZA for 5 years. He presented with abdominal pain and increased fatiguability for 7 days. His serum bilirubin and liver enzymes were elevated, and ultrasound revealed a dilated hepatic vein and portal vein suggestive of veno-occlusive liver disease. The clinical symptoms, liver functions, and ultrasound of the hepatobiliary system normalized after withdrawal of AZA.

Conclusion: A possibility of AZA veno-occlusive hepatoxicity should be considered in an MG patient if presented with abdominal pain, elevated bilirubin and transaminases and ultrasound showing dilatation of hepatic veins. Physicians should be aware of this complication because this toxicity is reversible following dose reduction or withdrawal of AZA.