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Azathioprine-related myelosuppression in a patient homozygous for TPMT*3A

Nature Reviews Nephrology volume 7, pages 478–484 (2011)Cite this article

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Abstract

Background. A 50-year-old man who had received a simultaneous pancreas and kidney transplant 9 years earlier developed pancytopenia 3 weeks after starting azathioprine therapy to treat worsening proteinuria suspected to be caused by sirolimus.

Investigations. Laboratory tests, including complete blood counts, measurement of serum levels of vitamin B12 and folate, liver function tests, virological assays, and thiopurine S-methyltransferase (TPMT) genotyping.

Diagnosis. Severe myelosuppression as a consequence of azathioprine therapy in a patient homozygous for the TPMT*3A allele.

Management. Discontinuation of azathioprine, treatment with an erythropoiesis-stimulating agent, red blood cell transfusions, filgrastim (a granulocyte colony-stimulating factor analogue) and folic acid.

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Figure 1: Trend in complete blood counts after starting (green arrows) and stopping (purple arrows) azathioprine therapy.
Figure 2: Azathioprine metabolism.
Figure 3: Role of folate, MTHFR and S-adenosylmethionine in azathioprine metabolism.

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  1. P. Budhiraja budhirajap@yahoo.com

Authors and Affiliations

  1. Southern Arizona Veterans Affairs Health Care System, 3601 South 6th Avenue, Tucson, 85723, AZ, USA

    Pooja Budhiraja & Mordecai Popovtzer

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  1. Pooja Budhiraja
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P. Budhiraja and M. Popovtzer contributed equally to researching data for this article, discussion of content, writing, and reviewing and editing of the manuscript before submission.

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Budhiraja, P., Popovtzer, M. Azathioprine-related myelosuppression in a patient homozygous for TPMT*3A. Nat Rev Nephrol 7, 478–484 (2011). https://doi.org/10.1038/nrneph.2011.74

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