Two Cases of Veno-occlusive Disease/Sinusoidal Obstruction Syndrome After Thioguanine Treatment for Acute Lymphoblastic Leukemia

Defibrotide for the Treatment of Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome in Paediatric Patients Who Did Not Receive Haematopoietic Stem Cell Transplantation: Case Reports of Patients From a German Academic Hospital

Introduction

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening condition characterised by obstruction of the small veins of the liver. Although typically associated with haematopoietic stem cell transplantation, VOD/SOS may also occur following intensive multimodal chemotherapy regimens. In children, symptoms of VOD/SOS are refractory thrombocytopaenia, weight gain, hepatomegaly, ascites and fluid retention, hyperbilirubinaemia and sometimes right upper quadrant pain.

Methods

Here, we present a case series of six paediatric patients with acute lymphoblastic leukaemia who developed severe VOD/SOS while receiving standard AIEOP-BFM ALL protocol treatment.

Results/Conclusions

All patients responded promptly to defibrotide treatment and exhibited favourable clinical outcomes.

Trial Registration

The authors have confirmed clinical trial registration is not needed for this submission.

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

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.