Thiopurine-Induced Myelosuppression with Severe Sepsis in a Patient with Crohn's Disease: A Case Report

A 17-year-old patient with Crohn's disease experienced severe hematological toxicity, including pancytopenia, neutropenic sepsis, and alopecia, after 3 weeks of azathioprine treatment. Despite having a wild-type TPMT genotype, the patient was homozygous for the NUDT 15 C415T variant, which is associated with increased risk of thiopurine-induced myelosuppression. Azathioprine was discontinued, and broad-spectrum antibiotics were administered, leading to initial clinical improvement. However, the patient later developed intestinal obstruction and postoperative complications, resulting in death. This case underscored the importance of pharmacogenomic testing, particularly for the NUDT 15 variant, before initiating azathioprine therapy, especially in Asian populations.