Coexisting or Underlying Risk Factors of Hepatic Veno-Occlusive Disease in Pediatric Hematopoietic Stem Cell Transplant Recipients Receiving Prophylaxis
ABSTRACT To evaluate the characteristics of veno-occlusive disease in pediatric hematopoietic stem cell transplant recipients, and their effect as a prophylactic regimen on severity and outcome.
This study included 204 allogeneic hematopoietic stem cell transplants performed on 187 children whose data retrospectively described the risk factors, prophylaxis, and treatment modalities of veno-occlusive disease. A prophylactic regimen composed of enoxaparin versus ursodeoxycholic acid and vitamin E was given to 167 of 204 patients.
Veno-occlusive disease developed in 22 patients (10.8%). Nineteen patients experienced veno-occlusive disease despite this prophylactic regimen. The prophylaxis seemed ineffective in preventing veno-occlusive disease (P = .657). Regarding risk factors, oral busulphan use, liposomal amphotericin B vancomycin treatment, and total parenteral nutrition were associated with an increased risk of veno-occlusive disease. Conversely, renal impairment also was associated with increased mortality in patients with veno-occlusive disease. The mortality rate in the first 100 days after a hematopoietic stem cell transplant was higher in the patients with veno-occlusive disease than it was in those without the disease.
Our prophylactic regimen may have played a role in the fairly low incidence of veno-occlusive disease in a pediatric population with high-risk features.
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ABSTRACT: Hepatic sinusoidal obstruction syndrome (SOS) is an obliterative venulitis of the terminal hepatic venules, which in its more severe forms imparts a high risk of mortality. SOS, also known as veno-occlusive disease (VOD), occurs as a result of cytoreductive therapy prior to hematopoietic stem cell transplantation (HSCT), following oxaliplatin-containing adjuvant or neoadjuvant chemotherapy for colorectal carcinoma metastatic to the liver and treated by partial hepatectomy, in patients taking pyrrolizidine alkaloid-containing herbal remedies, and in other particular settings such as the autosomal recessive condition of veno-occlusive disease with immunodeficiency (VODI). A central pathogenic event is toxic destruction of hepatic sinusoidal endothelial cells (SEC), with sloughing and downstream occlusion of terminal hepatic venules. Contributing factors are SEC glutathione depletion, nitric oxide depletion, increased intrahepatic expression of matrix metalloproteinases and vascular endothelial growth factor (VEGF), and activation of clotting factors. The clinical presentation of SOS includes jaundice, development of right upper-quadrant pain and tender hepatomegaly, ascites, and unexplained weight gain. Owing to the potentially critical condition of these patients, transjugular biopsy may be the preferred route for liver biopsy to exclude other potential causes of liver dysfunction and to establish a diagnosis of SOS. Treatment includes rigorous fluid management so as to avoid excessive fluid overload while avoiding too rapid diuresis or pericentesis, potential use of pharmaceutics such as defibrotide, coagulolytic agents, or methylprednisolone, and liver transplantation. Proposed strategies for prevention and prophylaxis include reduced-intensity conditioning radiation for HSCT, treatment with ursodeoxycholic acid, and inclusion of bevacizumab with oxaliplatin-based chemotherapeutic regimes. While significant progress has been made in understanding the pathogenesis of SOS and in mitigating against its adverse outcomes, this condition remains a serious complication of a selective group of medical treatments.