6-Mercaptopurine-Associated Sinusoidal Obstructive Syndrome During Interim Maintenance I: A Case Report

Katie Voelz; Gwendolyn Miller; Cathy Lee-Miller

doi:10.1097/MPH.0000000000002883

6-Mercaptopurine-Associated Sinusoidal Obstructive Syndrome During Interim Maintenance I: A Case Report

J Pediatr Hematol Oncol. 2024 May 23. doi: 10.1097/MPH.0000000000002883. Online ahead of print.

Authors

Katie Voelz^{1

2}, Gwendolyn Miller³, Cathy Lee-Miller^{1

2}

Affiliations

¹ Department of Pediatrics.
² Division of Pediatric Hematology, Oncology and Bone Marrow Transplant.
³ University of Wisconsin School of Medicine & Public Health, Madison, WI.

PMID: 38775421
DOI: 10.1097/MPH.0000000000002883

Abstract

Thiopurine-methyltransferase (TPMT) and nudix-hydrolase-15 (NUDT15) are enzymes relevant to the metabolism of thiopurine medications, used to treat immunologic disorders and malignancies. Standard dosing administered in the setting of TPMT/NUDT15 dysfunction can cause excessive cytotoxic metabolites and life-threatening complications. We describe an adolescent with high-risk B-cell acute lymphoblastic leukemia (ALL) whose TPMT/NUDT15 status was unknown due to lack of insurance approval for genetic testing. He subsequently developed myelosuppression and severe veno-occlusive disease (VOD) after receiving 6-mercaptopurine (6-MP). Our patient provides an example of a very rare 6-MP-related toxicity and the potential benefit of TPMT/NUDT15 screening before initiating thiopurine therapy.