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Azathioprine-related myelosuppression in a patient homozygous for TPMT*3A
Pooja Budhiraja1, Mordecai Popovtzer
1Southern Arizona Veterans Affairs Health Care System, 3601 South 6th Avenue, Tucson, AZ 85723, USA. budhirajap@yahoo.com
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 B(12) 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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