Azathioprine-induced myelosuppression in a pemphigus patient with a heterozygous mutation in the NUDT15 gene

Abstract

A 49-year-old male patient presented with repeated oral erosions for 1 year, as well as cutaneous erythema and blisters for 1 month. According to histopathological examination and detection of specific antibodies of pemphigus, the patient was diagnosed with pemphigus vulgaris. After the treatment with oral prednisone and azathioprine for 1 month, the white blood cell count and segmented neutrophilic granulocyte count both decreased. After withdrawal of azathioprine, the patient was subcutaneously injected with 150 μg recombinant human granulocyte colony-stimulating factor for 1 session. Then, the white blood cell count became normal. Genotyping test revealed that the patient carried a heterozygous mutation in the NUDT15 gene (JZ274) , and was homozygous for wild-type TPMT*2, TPMT*3C and ITPA genes. The patient was diagnosed with azathioprine-induced myelosuppression. Key words: Azathioprine; Pemphigus; Heterozygote; Bone marrow; NUDT15