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

Importance of NUDT15 Polymorphisms in Thiopurine Treatments

Thiopurines, mercaptopurine, and azathioprine are used as immunosuppressants in the treatments of inflammatory bowel disease, rheumatoid arthritis, and organ transplantation and as chemotherapeutic drugs for the treatment of acute leukemia and chronic myeloid leukemia. This drug class sometimes causes severe adverse reactions, including bone marrow suppression and hair loss. Genetic polymorphisms of the metabolizing enzyme thiopurine S-methyltransferase have been used for predicting these reactions in Caucasians, but these allele frequencies are less frequently observed in Asian populations. Recently, nudix hydrolase 15 (NUDT15) polymorphisms have been shown to play an important role in thiopurine-induced adverse reactions in Asians. In this review, we summarize the NUDT15 studies, mainly in Asian countries, and their implementation in several countries.

Azathioprine-induced toxoplasma gondii infection in a patient with Crohn's disease with NUDT15 variation: A case report

INTRODUCTION

Azathioprine (AZA) has been widely used for the treatment of various immune-related diseases and has become a mainstay in the treatment of inflammatory bowel disease. However, patients with genetic mutations may experience severe adverse events when treated with azathioprine. Most of the previous literature focused on the TPMP gene-related adverse reactions, herein, we report a case of Crohn's disease patient with nucleoside diphosphate-linked moiety X motif 15 gene (NUDT15) variation and wild-type TPMP gene who developed toxoplasma gondii infection after azathioprine treatment.

PATIENT CONCERNS

A 56-year-old Crohn's disease patient developed toxoplasma gondii infection within 2 months after the administration of azathioprine; however, he had no relevant high-risk factors.

DIAGNOSIS

Subsequent genetic testing revealed that the patient was heterozygous for NUDT15. Therefore, it was reasonable to consider that the patient's genetic mutation resulted in reduced tolerance to azathioprine, leading to low immunity and eventually toxoplasma infection.

INTERVENTIONS

AZA was then discontinued; after anti-infection, antipyretic and other supportive treatments were administered, the patient's condition gradually improved.

OUTCOMES

The patient was followed up at 1, 3, and 6 months after discharge; fortunately, he was in good health.

CONCLUSION

We report a case of Crohn's disease in a patient who developed severe pneumonia caused by toxoplasma gondii infection due to the administration of AZA, with normal TPMP gene but NUDT15 gene mutation. This indicates that NUDT15 variation may contribute to severe adverse events in patients treated with azathioprine, and we suggest that NUDT15 genotype be detected before the use of azathioprine in order to provide personalized therapy and reduce side effects.

Rituximab associated necrosis: A case report

BACKGROUND

Rituximab is a B-cell-depleting unconjugated monoclonal IgG1 antibody that targets the transmembrane protein CD20. This article reports on a case with the rare complication known as Rituximab-associated mucosal necrosis.

CASE PRESENTATION

The present case report addresses, for the first time, a patient affected by Devic's syndrome presenting with oral manifestations of palatal necrosis after rituximab treatment.

CONCLUSION

The present case raises the possibility of anti-CD20 antibody contributing to the development of palatal mucosal necrosis in some patients. Given the increasing administration of rituximab as a result of its efficacy against several diseases, a report on the potential iatrogenic effects of this drug is essential.