Azathioprine-induced Agranulocytosis and Severe Alopecia After Kidney Transplantation Associated With a NUDT15 Polymorphism: A Case Report

Background. Azathioprine (AZA) is the drug recommended for the continuation of immunosuppressive treatment after renal transplant in women during pregnancy. Case Report. A 37-year-old Japanese female developed agranulocytosis and severe alopecia after initiation of AZA (50 mg), used as an alternative to mycophenolate mofetil (MMF, 1000 mg) therapy in anticipation of a planned pregnancy. Within 4 days of the initiation of AZA therapy, the patient developed a high fever, leucopenia, and cranial alopecia. Genetic testing revealed a homozygous polymorphism of NUDT15 (rs116855232, NM_018283.3:c.415C>T: p.Arg139Cys), which has previously been identified as a risk factor for AZA-related complications in patients with inflammatory bowel disease. Conclusion. Genetic screening for NUDT15 could contribute to the prevention of serious adverse reactions to AZA and provide the opportunity for personalized medicine. Identification of a safe alternative to MMF during pregnancy after a renal transplant is a problem to be resolved in the future.