Defibrotide for the Treatment of Hepatic Veno-Occlusive Disease: Final Results From the International Compassionate-Use Program

Post-allogeneic Hematopoietic Stem Cell Transplantation Portal Hypertension Not Associated with Liver Cirrhosis, Veno-occlusive Disease, or Graft-versus-host Disease

We herein report a rare case of idiopathic portal hypertension (IPH)-like disease that developed after allogeneic hematopoietic stem cell transplantation (allo-HSCT). A 53-year-old woman who underwent allo-HSCT for acute myeloid leukemia showed portal hypertension with radiological and histopathological findings consistent with IPH, distinct from veno-occlusive disease (VOD) and graft-versus-host disease (GVHD) of the liver. This case highlights the importance of considering IPH-like disease as a potential cause of portal hypertension after allo-HSCT. Awareness of this complication can aid in the early diagnosis and appropriate management of patients post allo-HSCT.

Clinical features and risk factors of hepatic sinusoidal obstruction syndrome in children after hematopoietic stem cell transplantation: A single-center experience

Hepatic sinusoidal obstruction syndrome (SOS) is an illness with serious life effects that develops after hematopoietic stem cell transplantation (HSCT). We investigated the risk factors and clinical features of hepatic SOS in children following HSCT in 210 children who underwent allogeneic or autologous HSCT between 2009 and 2021 were analyzed in the context of SOS. The syndrome developed in 22 (10.4%) patients:frequently in neuroblastoma [24% (5/21)], hemophagocytic lymphohistiocytosis [57% (4/7)], and thalassemia major [22% (7/31)]. The median time from HSCT to diagnosis was 16 (6-38) days. Severe disease occurred in 8 (36%) patients, and mild/moderate in 14 (64%) and 4 patients died (18%). In univariate analyses, patient's age ≤ 2 years [odds ratio (OR)= 3.043, P = 0.028], pretransplant AST and ALT levels > 100 U/L (OR=3.576, P = 0.045), and chemotherapy/radiotherapy to abdomen before transplantation (OR = 3.162, P = 0.044) were determined as risk factors. In multivariate analysis, pre-transplant AST and ALT levels > 100 U/L (OR = 16.04, P = 0.010) and ferritin levels over 1000 mg/dl (OR=5.15, P = 0.047) were significant. The only independent risk factor on mortality was the age ≤ 2 years (P = 0.001). Although our study confirmed several risk factors for SOS, we failed to achieve some well-known risk factors. Precautions should be taken considering the factors affecting liver function before transplantation and the risk of SOS in infants receiving chemotherapy and radiotherapy before transplantation, such as neuroblastoma in which comparable results in respect to the chemotherapy only. The risk factors should be fully elucidated in multicenter studies to improve preventive and therapeutic strategies.

Diagnosing and Grading of Sinusoidal Obstructive Syndrome after Hematopoietic Stem Cell Transplant of Children, Adolescent and Young Adults treated in a Pediatric Institution with Pediatric Protocols

Sinusoidal obstructive syndrome (SOS), or veno-occlusive disease, of the liver has been recognized as a complex, life-threatening complication in the posthematopoietic stem cell transplant (HSCT) setting. The diagnostic criteria for SOS have evolved over the last several decades with a greater understanding of the underlying pathophysiology, with 2 recent diagnostic criteria introduced in 2018 (European Society of Bone Marrow Transplant [EBMT] criteria) and 2020 (Cairo criteria). We sought out to evaluate the performance characteristics in diagnosing and grading SOS in pediatric patients of the 4 different diagnostic criteria (Baltimore, Modified Seattle, EBMT, and Cairo) and severity grading systems (defined by the EBMT and Cairo criteria). Retrospective chart review of children, adolescent, and young adults who underwent conditioned autologous and allogeneic HSCT between 2017 and 2021 at a single pediatric institution. A total of 250 consecutive patients underwent at least 1 HSCT at UCSF Benioff Children's Hospital San Francisco for a total of 307 HSCT. The day 100 cumulative incidence of SOS was 12.1%, 21.1%, 28.4%, and 28.4% per the Baltimore, Modified Seattle, EBMT, and Cairo criteria, respectively (P < .001). We found that patients diagnosed with grade ≥4 SOS per the Cairo criteria were more likely to be admitted to the Pediatric Intensive Care Unit (92% versus 58%, P = .035) and intubated (85% versus 32%, P = .002) than those diagnosed with grade ≥4 per EBMT criteria. Age <3 years-old (HR 1.76, 95% [1.04 to 2.98], P = .036), an abnormal body mass index (HR 1.69, 95% [1.06 to 2.68], P = .027), and high-risk patients per our institutional guidelines (HR 1.68, 95% [1.02 to 2.76], P = .041) were significantly associated with SOS per the Cairo criteria. We demonstrate that age <3 years, abnormal body mass index, and other high-risk criteria associate strongly with subsequent SOS development. Patients with moderate to severe SOS based on Cairo severity grading system may correlate better with clinical course based on ICU admissions and intubations when compared to the EBMT severity grading system.

Incidence and risk factors of early onset VOD/SOS differ in younger vs older adults after stem cell transplantation

ABSTRACT

Veno-occlusive disease (VOD) is a rare but potentially life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-SCT). Although increasing awareness and modern transplant techniques have mitigated risk, the interaction of historic risk factors in the current era with posttransplant cyclophosphamide (PTCy) is unknown. We performed a retrospective single-center analysis of adult patients aged ≥18 years undergoing allo-SCT (N = 1561) using predominately PTCy as graft-versus-host disease (GVHD) prophylaxis (72%). We found a higher rate of VOD at 16.8% (20 of 119) in those aged ≤25 years compared with 3.8% (55 of 1442) in those aged >25 years, with unique predictors of VOD within each cohort. Multivariate classification and regression tree (CART) analysis confirmed age as the primary independent determinant of the rate of VOD. Among patients aged 18 to 25 years, disease risk index (DRI; 31% with high/very high DRI vs 12% low/intermediate DRI; P = .03) and prior lines of chemotherapy (24% with >1 vs 6% with ≤1; P = .03) were the strongest predictors of VOD. Incidence of VOD in patients aged >25 years of age consistently ranged between 3% and 5% across most risk factors evaluated, with only hepatic factors (baseline elevation of bilirubin, aspartate transferase, alanine aminotransferase) or gemtuzumab exposure associated with increased rates of VOD. There was no significant difference in rates of VOD in those receiving PTCy compared with those receiving alternate GVHD prophylaxis. Our data highlight the differences in incidence and predictors of VOD between younger (≤25) and older (>25) adults undergoing allo-SCT.

Defibrotide modulates pulmonary endothelial cell activation and protects against lung inflammation in pre-clinical models of LPS-induced lung injury and idiopathic pneumonia syndrome

Introduction

A multiple organ dysfunction syndrome (MODS) workshop convened by the National Institute of Child Health and Human Development in 2015 identified acute respiratory distress syndrome (ARDS) and complications of allogeneic blood and marrow transplantation (allo-BMT) as contributors to MODS in pediatric patients. Pulmonary dysfunction also remains a significant complication of allo-BMT. Idiopathic pneumonia syndrome (IPS) defines non-infectious, acute, lung injury that occurs post-transplant. Injury and activation to endothelial cells (ECs) contribute to each form of lung inflammation.

Methods

Two murine models were employed. In an ARDS model, naïve B6 mice receive an intravenous (i.v.) injection of lipopolysaccharide (LPS). In the established model of IPS, naïve B6D2F1 mice receive lethal total body irradiation followed by BMT from either allogeneic (B6) or syngeneic (B6D2F1) donors. Lung inflammation was subsequently assessed in each scenario.

Results

Intravenous injection of LPS to B6 mice resulted in enhanced mRNA expression of TNFα, IL-6, Ang-2, E-, and P-selectin in whole lung homogenates. The expression of Ang-2 in this context is regulated in part by TNFα. Additionally, EC activation was associated with increased total protein and cellularity in broncho-alveolar lavage fluid (BALF). Similar findings were noted during the development of experimental IPS. We hypothesized that interventions maintaining EC integrity would reduce the severity of ARDS and IPS. Defibrotide (DF) is FDA approved for the treatment of BMT patients with sinusoidal obstruction syndrome and renal or pulmonary dysfunction. DF stabilizes activated ECs and protect them from further injury. Intravenous administration of DF before and after LPS injection significantly reduced mRNA expression of TNFα, IL6, Ang-2, E-, and P-selectin compared to controls. BALF showed decreased cellularity, reflecting less EC damage and leak. Allogeneic BMT mice were treated from day -1 through day 14 with DF intraperitoneally, and lungs were harvested at 3 weeks. Compared to controls, DF treatment reduced mRNA expression of TNFα, IL6, Ang-2, E-, and P- selectin, BALF cellularity, and lung histopathology.

Conclusion

The administration of DF modulates EC injury in models of ARDS and IPS. Cytokine inhibition in combination with agents that stabilize EC integrity may be an attractive strategy for patients in each setting.

Molecular Advances in Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease

Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) detected in the liver has been considered a severe complication of hematopoietic stem cell transplantation (HSCT). SOS/VOD is characterized by hepatomegaly, right upper quadrant pain, jaundice, and ascites. The severe forms of the disease may result in multi-organ dysfunction (MOD) with a high mortality rate (>80%). The development of SOS/VOD can be rapid and unpredictable. Therefore, early identification and severity assessment is crucial in facilitating prompt diagnosis and timely treatment. Effective treatment and potential prophylaxis with defibrotide highlight the need for characterizing a sub-group of patients at high risk for SOS/VOD. Moreover, antibodies that are conjugated with calicheamicin, gemtuzumab, and inotuzumab ozogamicin, have led to renewed interest in this syndrome. Evaluation and management of serious adverse events associated with gemtuzumab and inotuzumab ozogamicin are recommended. We review hepatic-, transplant- and patient-related risk factors, criteria for diagnosis and grading classification, and SOS/VOD potential biomarkers. Furthermore, we examine pathogenesis, clinical presentation, diagnostic criteria, risk factors, prophylaxis, and treatment of SOS/VOD occurring post HSCT. Moreover, we aim to provide an up-to-date summary of molecular advances in the diagnosis and management of SOS/VOD. We performed a comprehensive review of the literature and examined the recently available data, mostly using the PubMed and Medline search engines for original articles published over the last decade. In the era of precision medicine, our review provides up-to-date knowledge of genetic or sera markers for SOS/VOD with the goal of identifying a subset of high-risk patients.

Hepatobiliary disease after bone marrow transplant

INTRODUCTION

Bone marrow transplantation (BMT) is the standard treatment for several hematologic pathologies. Post-BMT patients may develop hepatobiliary complications that impact morbidity and mortality. The differential diagnosis may include drug-induced liver injury (DILI), sepsis-associated liver injury (SALI), sinusoidal obstruction syndrome (SOS), graft-versus-host disease (GVHD), viral hepatitis, ischemic and fulminant hepatitis, among others.

AREA COVERED

Defining the etiology of hepatobiliary injury is challenging due to the overlapping symptoms. Thus, it is necessary to be aware of and understand the clinical characteristics of these hepatobiliary complications and provide adequate management with possible better outcomes. We reviewed the scientific literature focused on early hepatobiliary complications associated with BMT. We searched the PubMed database using the following descriptors: hepatic complications, drug-induced liver disease, graft-versus-host disease, cholestasis, sepsis, sinusoidal obstruction syndrome, cytomegalovirus, viral hepatitis, bone marrow transplantation, and hematopoietic stem cell transplantation.

EXPERT OPINION

Post-BMT hepatobiliary complications comprise several differential diagnoses and are challenges for the hepatologist's clinical practice. When evaluating these patients, it is necessary to consider the temporality between the use of certain medications, the increase in liver enzymes, and the presence of infection, in addition to applying diagnostic criteria and complementary tests for a specific diagnosis.

Clinically relevant model of oxaliplatin-induced sinusoidal obstruction syndrome

AIM

Sinusoidal obstruction syndrome (SOS) induced by oxaliplatin-including chemotherapies (OXCx) is associated with impaired hepatic reserve and higher morbidity after hepatic resection. However, in the absence of an appropriate animal experimental model, little is known about its pathophysiology. This study aimed to establish a clinically relevant reproducible model of FOLFOX-induced SOS and to compare the clinical/histopathological features between the clinical and animal SOS settings.

METHODS

We performed clinical/pathological analyses of colorectal liver metastasis (CRLM) patients who underwent hepatectomy with/without preoperative treatment of FOLFOX (n = 22/18). Male micro-minipigs were treated with 50% of the standard human dosage of the FOLFOX regimen.

RESULTS

In contrast to the monocrotaline-induced SOS model in rats, hepatomegaly, ascites, congestion, and coagulative necrosis of hepatocytes were absent in patients with CRLM with OXCx pretreatment and OXCx-treated micro-minipigs. In parallel to CRLM cases with OXCx pretreatment, OXCx-challenged micro-minipigs exhibited deteriorated indocyanine green clearance, morphological alteration of liver sinusoidal endothelial cells, and upregulated matrix metalloproteinase-9. Using our novel porcine SOS model, we identified the hepatoprotective influence of recombinant human soluble thrombomodulin in OXCx-SOS.

CONCLUSIONS

With distinct differences between monocrotaline-induced rat SOS and human/pig OXCx-SOS, our pig OXCx-SOS model serves as a preclinical platform for future investigations to dissect the pathophysiology of OXCx-SOS and seek preventive strategies.

Endothelial Dysfunction Syndromes after Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only therapy with a curative potential for a variety of malignant and non-malignant diseases. The major limitation of the procedure is the significant morbidity and mortality mainly associated with the development of graft versus host disease (GVHD) as well as with a series of complications related to endothelial injury, such as sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD), transplant-associated thrombotic microangiopathy (TA-TMA), etc. Endothelial cells (ECs) are key players in the maintenance of vascular homeostasis and during allo-HSCT are confronted by multiple challenges, such as the toxicity from conditioning, the administration of calcineurin inhibitors, the immunosuppression associated infections, and the donor alloreactivity against host tissues. The early diagnosis of endothelial dysfunction syndromes is of paramount importance for the development of effective prophylactic and therapeutic strategies. There is an urgent need for the better understanding of the pathogenetic mechanisms as well as for the identification of novel biomarkers for the early diagnosis of endothelial damage. This review summarizes the current knowledge on the biology of the endothelial dysfunction syndromes after allo-HSCT, along with the respective therapeutic approaches, and discusses the strengths and weaknesses of possible biomarkers of endothelial damage and dysfunction.

Medical emergencies in pediatric blood & marrow transplant and cellular therapies

Hematopoietic stem cell transplant (HCT) is used for many pediatric malignant and non-malignant diseases. However, these patients are at a high risk for emergencies post-transplant, related to prior comorbidities and treatments for the underlying disease, high dose chemotherapy regimen related toxicities, prolonged myelosuppression, and opportunistic infections due to their immunocompromised state. Emergencies can be during preparative regimen and hematopoietic progenitor cell (HPC) infusion, acute post-transplant (pre-engraftment) and late during post engraftment. Infectious complications are the most common cause of morbidity and mortality in the peri-transplant period. Sinusoidal obstructive syndrome is another life-threatening emergency seen in children undergoing HCT, especially in infants. Timely recognition and administration of defibrotide with/without steroids is key to the management of this complication. Another complication seen is transplant associated thrombotic microangiopathy. It can cause multiorgan failure if left untreated and demands urgent identification and management with complement blockade agents such as eculizumab. Cytokine release syndrome and cytokine storm is an important life-threatening complication seen after cellular therapy, and needs emergent intervention with ICU supportive care and tocilizumab. Other complications in acute period include but are not limited to: seizures from busulfan or other chemotherapy agents, PRES (posterior reversible encephalopathy syndrome), diffuse alveolar hemorrhage, idiopathic pulmonary syndrome and allergic reaction to infusion of stem cells. Acute graft versus host disease (GvHD) is a major toxicity of allogeneic HCT, especially with reduced intensity conditioning, that can affect the skin, liver, upper and lower gastrointestinal tract. There has been major development in new biomarkers for early identification and grading of GvHD, which enables application of treatment modalities such as post-transplant cyclophosphamide and JAK/STAT inhibitors to prevent and treat GvHD. Myelosuppression secondary to the chemotherapy increases risk for engraftment syndrome as well as coagulopathies, thus increasing the risk for clotting and bleeding in the pediatric population. The purpose of this article is to review recent literature in these complications seen with pediatric hematopoietic cell transplant (HCT) and cellular therapies and provide a comprehensive summary of the major emergencies seen with HCT.

Immune-related generalised oedema - A new category of adverse events with immune checkpoint inhibitors

BACKGROUND

Generalised oedema was occasionally reported associated with immune checkpoint inhibitors (ICPIs). The purpose of this study is to investigate immune-related generalised oedema (ir-GE) drug related to ICPI, through frequency, clinical and pathological characteristics, and patient's outcome.

PATIENTS AND METHODS

Objectives of the study were to report on ir-GE associated with ICPI to define frequency, associated signs and symptoms, pathological characteristics, severity, and response to corticosteroids. To be included in the study, adult patients had to have ir-GE related to ICPI with certain or likely link, without any other known causes of generalised oedema. The study design was observational, over the period 2014-2020, from pharmacovigilance databases in France, including the prospective Registre des Effets Indésirables Sévères des Anticorps Monoclonaux Immunomodulateurs en Cancérologie (REISAMIC) registry. Calculation of the frequency of ir-GE was restricted to the prospective REISAMIC registry.

RESULTS

Over 6633 screened patients, 20 had ir-GE confirmed drug related to ICPI. Based on the prospective REISAMIC registry, the frequency of ir-GE was 0.19% of ICPI-treated patients (3 cases out of 1598 screened patients). The 20 patients with ir-GE had a median (range) age of 62 (26-81) years, most frequent tumour types were melanoma (n = 9; 45%) and lung cancer (n = 6; 30%). The most frequent localisations of oedema were peripheral (n = 17; 85%), pleural (n = 13; 65%), and peritoneal (n = 10; 50%). Polyserositis was observed in 11 (55%) patients. The median (range) weight gain per patient was 9 (2-30) kg. Associated signs and symptoms met criteria for capillary leak syndrome (n = 4; 20%), sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) (n = 3; 15%), or subcutaneous autoimmune syndrome (n = 2; 10%). Corticosteroids were administered to 15 patients; of them, 10 (67%) improved clinically after corticosteroids. Based on CTCAEV5.0, the highest severity of ir-GE was grade ≥4 in 11 (55%) patients and four (20%) patients died due to ir-GE.

CONCLUSIONS

Generalised immune system-related oedema is a new category of adverse event with immune checkpoint inhibitors and is often associated with a life-threatening condition. The pathophysiology may in some cases be related to endothelial dysfunctions, such as SOS/VOD or capillary leak syndrome.

Real-world use of defibrotide for veno-occlusive disease/sinusoidal obstruction syndrome: the DEFIFrance Registry Study

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of haematopoietic cell transplantation (HCT) conditioning. The DEFIFrance post-marketing registry study evaluated effectiveness and safety in patients who received defibrotide. It collected retrospective/prospective patient data from 53 French HCT centres from July 2014 to March 2020. Primary endpoints were survival and complete response (CR; total serum bilirubin <2 mg/dL, multiorgan failure resolution) at Day 100 post-HCT among patients with severe/very severe VOD/SOS. A secondary endpoint was evaluation of treatment-emergent serious adverse events (TESAEs) of interest. Of 798 patients analysed, 251 and 81 received defibrotide treatment for severe/very severe VOD/SOS and mild/moderate VOD/SOS post-HCT, respectively; 381 received defibrotide for VOD/SOS prophylaxis. In patients with severe/very severe VOD/SOS post-HCT, Kaplan-Meier-estimated CR at Day 100 was 74% (95% confidence interval [CI]: 66%, 81%). At Day 100, 137/251 (55%) were alive and in CR. Kaplan-Meier-estimated Day 100 post-HCT survival was 61% (95% CI: 55%, 67%) in patients with severe/very severe VOD/SOS. TESAEs of interest occurred in 29% of these patients; VOD/SOS-related mortality at 12 months was 15%. DEFIFrance represents the largest collection of real-world data on post-registration defibrotide use, supporting the real-world utility of defibrotide for patients with severe/very severe VOD/SOS post-HCT.

Interest of the preventive and curative use of defibrotide on the occurrence and severity of sinusoidal obstruction syndrome after hematopoietic stem cell transplant in children

Defibrotide (DF) is indicated for the treatment of severe sinusoidal obstruction syndrome (SOS) following hematopoietic stem cell transplantation (HSCT), but its prophylactic use against SOS is not recommended yet. This study describes the impact of the preventive and curative use of DF on reducing the incidence and severity of SOS in children. Patients aged 0-19 years, who received allogenic HSCT after myeloablative conditioning regimen with busulfan or total body irradiation in our comprehensive cancer center, between 2013 and 2017, were included. The Baltimore or modified Seattle criteria were used for SOS diagnosis. SOS was graded using the 2017 European Society for Blood and Marrow Transplantation classification defining severity criteria of SOS in children. SOS occurrence tended to decrease with prophylactic DF, but no significant difference was observed in terms of severity. When not treated with preventive DF, 50% (19/38) of the patients with SOS were graded severe to very severe, but only 37% (7/19) had organ dysfunction. Curative DF was administered at a median of 2 days post-HSCT, for a median of 6.5 days. The absence of fatal SOS supports the use of early curative DF with acceptable toxicities and questions the optimal duration of DF treatment.

Abdominal Complications During Treatment for Pediatric Acute Myeloid Leukemia

Acute myeloid leukemia (AML) accounts for 15% to 20% of childhood leukemias. Because of high-intensive therapy, up to 5% of patients suffer from treatment-related mortality (TRM). Abdominal complications are frequent, however, literature on this subject is sparse. We aimed to characterize severe abdominal pain (AP) and hyperbilirubinemia experienced by pediatric AML patients treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO)-AML 2004 protocol (n=313). Patients were censored at hematopoietic stem cell transplantation and relapse. Toxicity information was collected prospectively. Additional information was requested retrospectively from the treating centers. Sixteen episodes of hyperbilirubinemia and 107 episodes of AP were reported. The treating centers deemed infection (30%) and typhlitis (18%) as the most frequent causes of AP. Six patients developed appendicitis (2%). Patients experiencing concurrent AP and sepsis had a high risk of TRM (36%, n=4). Eighty percent of episodes with hyperbilirubinemia fulfilled the European Society for Bone and Marrow Transplantation criteria for sinusoidal obstruction syndrome. In conclusion, abdominal complications were frequent with infection considered the predominate cause. Most patients with hyperbilirubinemia fulfilled the criteria for sinusoidal obstruction syndrome. AML treatment might be associated with appendicitis. Patients suffering from concurrent AP and sepsis had a high risk of TRM indicating that high awareness of abdominal complications is essential to reduce mortality, especially during sepsis.

Defibrotide Prophylaxis of Sinusoidal Obstruction Syndrome in Adults Treated With Inotuzumab Ozogamicin Prior to Hematopoietic Stem Cell Transplantation

Sinusoidal Obstruction Syndrome (SOS) is a life threatening HSCT complication and it can rapidly evolve in Multiple Organ Dysfunction Syndrome, with a mortality exceeding 80%. Early treatment with defibrotide is the leading factor for efficacy. Its prophylactic use is recommended in the pediatric setting, but its value isn’t validated for adults, although factors for individual risk assessment are debated. We here present a real-world experience of Defibrotide prophylaxis in adults at very high risk of SOS. We treated with prophylactic Defibrotide and Ursodeoxycholic Acid seven patients receiving allogeneic HSCT for high risk B-ALL, previously treated with single agent Inotuzomab-Ozogamicin. They all had other high risk factors for SOS such as previous hepatotoxicity, previous allo-HSCT, double alkylating conditioning. All patients received Treosulfan-Fludarabine conditioning, Thiotepa was added in 4 patients and 4GyTBI in 2 patients. GvHD prophylaxis included post-transplant cyclophosphamide, rapamycin and mycophenolate. Donor source was PBSC. Five patients received family MMRD transplant, 1 patient a MRD transplant and 1 patient a MUD transplant. Non-severe gastrointestinal bleeding occurred in two patients requiring defibrotide temporarily discontinuation. SOS occurred in 3/7 cases within 21 days after HSCT and no late-onset SOS were diagnosed. SOS caused death in all cases. All three patients were characterized by a common pattern of very high risk factors by prior HSCT, they all received a myeloablative conditioning with Treosulfan-Thiotepa and a MMRD transplant. Defibrotide prophylaxis apparently failed to protect against the development of SOS in those patients treated with a double alkylator-based conditioning regimen, while a possible efficacy for the other high-risk patients is debatable.

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

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation conditioning or high-dose chemotherapy. The underlying pathogenesis involves toxic injury to hepatocytes and sinusoidal endothelial cells. Presenting symptoms include ascites, weight gain, hepatomegaly, and hyperbilirubinemia. Severe VOD/SOS with multiorgan failure has a mortality rate of >80% if left untreated. Thioguanine, a chemotherapy drug used to treat acute lymphoblastic leukemia, has been shown to cause VOD/SOS. Here, we describe cases of 2 patients who developed very severe VOD/SOS after starting thioguanine for acute lymphoblastic leukemia; both achieved complete remission with defibrotide and experienced no defibrotide-related adverse events.

Influence of creatinine levels on survival in patients with veno-occlusive disease treated with defibrotide

BACKGROUND/AIMS

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is one of the most fatal complications of hematopoietic cell transplantation (HCT), and defibrotide is the only curative drug. We conducted this study to confirm the survival rate of VOD/SOS patients diagnosed in Korea and assess the efficacy of defibrotide.

METHODS

Patients diagnosed with VOD/SOS after allogenic HCT between 2003 and 2020 were enrolled. We investigated day +100 survival rates and associated risk factors in patients who satisfied the modified Seattle criteria within 50 days of HCT.

RESULTS

A total of 110 patients satisfied the modified Seattle criteria, of which 65.5% satisfied the Baltimore criteria. Thirty-seven patients were treated with defibrotide. The day +100 survival rate of the 110 patients was 65.3%. The survival rates in patients who did not meet the Baltimore criteria and in those who did were 86.8% and 53.7%, respectively (p = 0.001). The day +100 survival rate of patients treated with defibrotide was 50.5%. Among the patients receiving defibrotide, those whose creatinine levels were more than 1.2 times the baseline had a significantly lower survival rate at 26.7% (p = 0.014). On multivariate regression analysis, the hazard ratio of satisfaction of the Baltimore criteria was 4.54 (95% confidence interval [CI], 1.69 to 12.21; p = 0.003). In patients treated with defibrotide, the hazard ratio was 8.70 (95% CI, 2.26 to 33.45; p = 0.002), when creatinine was more than 1.2 times the baseline on administration.

CONCLUSION

The day +100 survival rate was significantly lower when the Baltimore criteria were satisfied, and when there was an increase in creatinine at the time of defibrotide administration.

Endothelial cell dysfunction: a key determinant for the outcome of allogeneic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (alloSCT) carries the promise of cure for many malignant and non-malignant diseases of the lympho-hematopoietic system. Although outcome has improved considerably since the pioneering Seattle achievements more than 5 decades ago, non-relapse mortality (NRM) remains a major burden of alloSCT. There is increasing evidence that endothelial dysfunction is involved in many of the life-threatening complications of alloSCT, such as sinusoidal obstruction syndrome/venoocclusive disease, transplant-associated thrombotic microangiopathy, and refractory acute graft-versus host disease. This review delineates the role of the endothelium in severe complications after alloSCT and describes the current status of search for biomarkers predicting endothelial complications, including markers of endothelial vulnerability and markers of endothelial injury. Finally, implications of our current understanding of transplant-associated endothelial pathology for prevention and management of complications after alloSCT are discussed.

Progressive endothelial cell damage in correlation with sepsis severity. Defibrotide as a contender

BACKGROUND

The vascular endothelium plays a key role in sepsis pathophysiology and the associated organ dysfunction.

METHODS

We evaluated endothelial function in an experimental in vitro model of sepsis, using endothelial cells grown in the presence of serum from patients with septic syndromes (sepsis, severe sepsis, and septic shock), noninfectious systemic inflammatory response syndrome (NI-SIRS) and healthy volunteers. Experiments were performed in the absence and presence of defibrotide (DF) (100 µg/ml) to evaluate its potential protective effect.

RESULTS

After exposure to patients' sera, there was a progressive endothelial cell activation in correlation with sepsis severity, with a proinflammatory and prothrombotic phenotype, exhibiting significantly increased expression of adhesion receptors at the surface (intercellular adhesion molecule-1, p < .05 and vascular cell adhesion molecule-1, p < .05); higher production and release to the extracellular matrix (ECM) of von Willebrand factor (p < .001); augmented thrombogenicity of the ECM toward platelets (p < .001); and increased phosphorylation of intracellular p38MAPK. DF prevented these changes in all groups.

CONCLUSIONS

Markers of endothelial damage increased progressively in association with the severity of septic syndromes. The endothelium is therefore an important therapeutic target to prevent complications of sepsis. DF shows promising potential to modulate the endothelial damage associated with sepsis and may constitute a pharmacological tool to decrease its sequelae including multiorgan failure.

Analysis of risk factors for hepatic sinusoidal obstruction syndrome following allogeneic hematopoietic stem cell transplantation in pediatric patients

Purpose

Hepatic sinusoidal obstruction syndrome (SOS) represents a serious complication following hematopoietic stem cell transplantation (HSCT). Our study aimed to investigate important risk factors of SOS in a pediatric population.

Methods

This retrospective study analyzed 105 children, adolescents and young adults who underwent allogeneic HSCT at our pediatric HSCT center in Jena. The observation period was 12 years and SOS was defined by the pediatric criteria of the European Society for Blood and Marrow Transplantation (EBMT).

Results

15 out of all 105 patients developed SOS (14.3%). The median time from HSCT to SOS diagnosis was 12 days. The mortality rate of SOS was 20.0%. In univariate analyses, we identified the significant risk factors of patient age < 1 year [odds ratio (OR) = 7.25, p = 0.037], prior treatment with gemtuzumab ozogamicin (OR = 11.00, p = 0.020), high pretransplant ferritin levels above 1500 ng/mL (OR = 4.00, p = 0.033), 2000 ng/mL (OR = 4.69, p = 0.016), and 2400 ng/mL (OR = 5.29, p = 0.005) as well as international normalized ratio (INR) ≥ 1.3 (OR = 5.91, p = 0.009). The following risk factors could be confirmed in multivariate analysis: treatment with gemtuzumab ozogamicin (OR = 9.24, p = 0.048), ferritin > 2400 ng/mL (OR = 5.74, p = 0.023), and INR ≥ 1.3 (OR = 8.02, p = 0.007).

Conclusion

Our study confirms several risk factors from the current literature. Additionally, this is the first report on the risk factor of high pretransplant INR.

A multicentre, multinational, prospective, observational registry study of defibrotide in patients diagnosed with veno-occlusive disease/sinusoidal obstruction syndrome after haematopoietic cell transplantation: an EBMT study

Severe hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of haematopoietic cell transplantation (HCT). This multinational, prospective, observational study (NCT03032016), performed by the EBMT, enrolled patients treated with defibrotide from April 2015 to July 2018. This analysis focused on defibrotide-treated patients with VOD/SOS post-HCT. The primary endpoint was incidence of serious adverse events (SAEs) of interest up to 12 months post-HCT in patients with severe VOD/SOS. Overall, 104 defibrotide-treated patients with VOD/SOS post-HCT were enrolled: 62 had severe VOD/SOS and comprised the primary study population, including 36 with multi-organ dysfunction/failure (MOD/MOF). SAEs of interest occurred in 20 of 62 (32%) severe VOD/SOS patients; the most common by category were infection (24%) and bleeding (13%). In patients with severe VOD/SOS, the Kaplan-Meier-estimated Day 100 survival rate was 73% (95% CI: 60%, 82%) with VOD/SOS resolution by Day 100 in 45 of 62 (73%) patients. MOD/MOF resolved in 19 of 36 (53%) patients with MOD/MOF at VOD/SOS diagnosis. Results from this multicentre registry study build on prior defibrotide studies supporting the utility of defibrotide for the treatment of VOD/SOS post-HCT. These results provide additional real-world evidence of the effectiveness and safety of defibrotide in patients with VOD/SOS post-HCT.

Veno-occlusive Disease in HSCT Patients: Consensus-based Recommendations for Risk Assessment, Diagnosis, and Management by the GITMO Group

Variation in clinical practice affects veno-occlusive disease management, mainly in patients who undergo allogeneic hematopoietic stem cell transplantation. Disputes about diagnostic criteria, treatment, and prophylaxis, due to the lack of high-quality data, are at the base of this variability. With the aim of limiting inconsistency in clinical care, thus improving both patient outcomes and data collection reliability, the Italian Society of Stem cell transplant (Gruppo Italiano Trapianto Midollo Osseo e Terapia Cellulare) launched a collaborative effort to formulate recommendations based on integration of available evidence and expert's consensus. A systematic method, according to US National Institute of Health guidelines and Italian National System for Guidelines, was used. Twenty-nine recommendations were approved with a strong (20) or weak (9) level of agreement, while 26 were rejected. In particular, the panel pointed out the need to achieve an early diagnosis, encouraging the adoption of European Society for Blood and Marrow Transplantation criteria and the prompt use of ultrasonography. Moreover, our experts strongly recommended in favor of prophylactic use of ursodeoxycholic acid. As soon as a veno-occlusive disease diagnosis is established, treatment with defibrotide should be started for at least 21 days. A number of areas of uncertainty, particularly concerning risk stratification and use of diagnostic tools such as elastography has been identified and discussed.

Defibrotide in hematopoietic stem cell transplantation: A multicenter survey study of the Spanish Hematopoietic Stem Cell Transplantation Group (GETH)

BACKGROUND

Defibrotide is approved in European Union for the treatment of severe sinusoidal obstruction syndrome (SOS) after HSCT. However, it has also been used for SOS prophylaxis, moderate SOS and in other complications such as transplant-associated thrombotic microangiopathy (TAM). The objective of this study was to evaluate current uses, effectiveness and safety of defibrotide in patients with HSCT.

METHODS

This multicenter, retrospective study included patients treated with defibrotide for any indication at 28 HSCT centers of the Grupo Español de Trasplante Hematopoyetico (GETH) including the pediatric subgroup Grupo Español de Trasplante de Medula en Niños (GETMON).

RESULTS

Three hundred and eighty eight patients treated with defibrotide between January 2011 and December 2018 were included. 253 patients were children, and 135 patients were adults. In total, 332 transplants were allogeneic, and the remainder were autologous. Main indications for defibrotide use were severe/very severe SOS in 173 patients, SOS prophylaxis in 135 patients, moderate SOS in 41 patients, TAM in six patients and suspected SOS in 33 patients. Overall survival (OS) at day +100 in the SOS prophylaxis group was 89% (95% CI, 87%-91%). In the group of patients with moderate and severe/very severe SOS, the OS at day +100 was 80% (95% CI, 74%-86%) and 62% (95% CI, 59%-65%), respectively (P = .0015). With a longer follow-up, median of 2 years (4 months-7 years), OS was 63% (95% CI, 59%-67%) in the SOS prophylaxis patients. OS for patients with moderate and severe/very severe SOS groups was 53% (95% CI, 47%-61%) and 26% (95% CI, 22%-30%), respectively (P = .006). 191 patients died, and SOS was the main cause of death in 23 patients (12%).

CONCLUSIONS

Defibrotide has an acceptable safety profile with an improved response in severe/very severe SOS compared with historical controls, mainly in pediatric patients. Use of defibrotide for prophylaxis may improve prognosis of patients at high risk of complications due to endothelial damage such as those who receive a second transplant. SOS has an important impact on the HSCT long-term survival, as can be concluded from our study.

Early and late-onset veno-occlusive disease/sinusoidal syndrome post allogeneic stem cell transplantation - a real-world UK experience

Classical veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a serious complication post allogeneic hematopoietic stem cell transplantation (HSCT). Before the recently revised EBMT criteria, the Baltimore and modified Seattle criteria failed to recognize the syndrome of late-onset VOD. We present real-world experience from a large UK transplant center reporting on VOD/SOS in consecutive HSCT adult patients (n = 530), transplanted for hematological cancers. We identified 27 patients treated with Defibrotide for VOD/SOS diagnosis, where detailed data were available for final analysis. Using standard definitions including EBMT criteria, around 30% (n = 8/27) of cases classified as late-onset VOD presenting at median of 46 (22-93) days but with D100 survival (63% vs 58%, Log-rank; P = 0.81) comparable to classical VOD. Hazard ratio for D100 mortality was 2.82 (95% CI: 1.74-4.56, P < .001, Gray test) with all VOD/SOS events. Twenty percent (n = 2/8) of late-onset VOD patients were anicteric and 42% (n = 8) classical VOD patients presented with refractory thrombocytopenia, while less than half met EBMT criteria for classical VOD in adults, highlighting gaps in real-world diagnostic limitations using EBMT criteria. However, challenges remain about underrecognition and difficulties related to early defibrotide access for treatment of late-onset VOD in current treatment guidelines. Our report strongly supports early Defibrotide for the treatment of severe VOD/SOS in adults regardless of time of onset.

Cost-effectiveness analysis of defibrotide in the treatment of patients with severe veno-occlusive disease/sinusoidal obstructive syndrome with multiorgan dysfunction following hematopoietic cell transplantation in Spain

AIMS

This study evaluated cost-effectiveness of defibrotide vs best supportive care (BSC) for the treatment of hepatic veno-occlusive disease/sinusoidal obstructive syndrome (VOD/SOS) with multiorgan dysfunction (MOD) post-hematopoietic cell transplantation (HCT) in Spain.

MATERIALS AND METHODS

A two-phase Markov model, comprising a 1-year acute phase with daily cycles and a lifetime long-term phase with annual cycles, was adapted to the Spanish setting. The model included a cohort of patients with severe VOD/SOS (defined as VOD/SOS with MOD) post-HCT. For the acute phase, efficacy and VOD/SOS-related length of stay were obtained from a phase 3 defibrotide study (NCT00358501). VOD/SOS-related hospital stays were 7.5 and 23.2 days in defibrotide-treated and BSC patients, respectively. Defibrotide-treated patients spent 30% of their stay in the intensive care unit vs 60% in BSC patients. Assumptions for the long-term phase and utility values were obtained from the literature. Costs were from the Spanish Health System perspective (€2019). Defibrotide cost was based on 25 mg/kg/day over 17.5 days, using local expert opinion. Life-years (LYs), quality-adjusted LYs (QALYs), and costs were estimated over a lifetime horizon, applying a 3% discount rate for costs and outcomes. Sensitivity analyses assessed the robustness of the results.

RESULTS

Defibrotide produced an additional 1.214 QALYs and 1.348 LYs vs BSC, with a total cost of €33,708 more than BSC alone. However, defibrotide resulted in savings up to €16,644/patient for cost of hospital stay. Difference between costs and effective measures led to ratios of €27,757/QALY and €25,007/LY gained. Additional hospital stays had the greatest influence on base-case results. Probabilistic analysis confirmed the robustness of the deterministic results.

LIMITATIONS

Limitations include use of historical controls and assumptions extrapolated from the literature.

CONCLUSIONS

This cost-effectiveness model, adapted to the Spanish setting, showed that defibrotide is a cost-effective alternative to BSC alone in patients with severe VOD/SOS post-HCT.

Prognostic factors for pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome: a multicenter study in China

Background

In China, one of the major causes of hepatic sinusoidal obstruction syndrome (HSOS) is the intake of herbals containing pyrrolizidine alkaloid (PA). However, prognostic factors for PA-induced HSOS are poorly understood. The aim of this study was to identify the independent prognostic factors for PA-induced HSOS using a multi-center study.

Methods

A total of 117 PA-induced HSOS patients were enrolled for data collection in three university hospitals from November 2003 to September 2018. Univariate and multivariate Cox proportional hazards analysis were used to determine prognostic factors for PA-induced HSOS.

Results

The median age of the PA-induced HSOS patients was 61 years (range, 21–88 years), and 64% of them were male. The survival rates at 1, 3, and 36 months were 89.71%, 72.60%, and 69.19%, respectively. Significant differences in prothrombin time (PT), international normalized ratio, total bilirubin, severity grading [new criteria for severity grading of hematopoietic stem cell transplantation (HSCT)-related HSOS in adults] were found between patients who survived and those who died. Univariate and multivariate survival analysis using Cox’s regression model demonstrated low serum albumin (<35 g/L), elevated serum urea (>8.2 mmol/L) and severe or very severe HSOS (European Society for Blood and Marrow Transplantation 2016 criteria) were independent prognostic factors of survival.

Conclusions

Serum albumin, serum urea, and severity grading were independent prognostic factors for patients with PA-induced HSOS, and can contribute to identifying potentially high-risk patients for early effective intervention.

Trial registration

ChiCTR-DRD-17010709 (www.chictr.org.cn).

Role of endothelial-microparticles and the tissue factor pathway in ginsenoside Rb1-mediated prevention of umbilical vein endothelial cell injury

Hepatic veno-occlusive disease (VOD) is a life-threatening complication of hematopoietic stem cell transplantation, which urgently requires effective prevention and treatment. Endothelial damage is recognized as the first event in patients with hepatic VOD. However, the mechanism by which endothelial injury induces thrombosis in hepatic VOD is still not clear. In the present study, monocrotaline (MCT) was used to induce endothelial cell injury in EA.hy926 cells to imitate in vitro hepatic VOD. MCT significantly increased apoptosis in EA.hy926 endothelial cells and the secretion of endothelial microparticles (EMPs) which can be used to reflect the level of endothelial injury. Additionally, MCT significantly enhanced the expression of soluble tissue factor (TF) and EMP-bound TF protein, suggesting that EMPs may participate in the development of hepatic VOD by regulating coagulation. Ginsenoside Rb1, a major constituent and effective ingredient of Panax ginseng, was found to significantly decrease MCT-induced endothelial injury and release of EMPs. Moreover, Ginsenoside Rb1 decreased soluble TF released by EA.hy926 cells and EMP-bound TF protein induced by MCT. These data suggest that ginsenoside Rb1 may serve as a potent prophylactic and/or as a treatment of hepatic VOD by protecting endothelial cells and preventing microthrombosis induced by endothelial injury.

Insulin-like growth factor-I predicts sinusoidal obstruction syndrome following pediatric hematopoietic stem cell transplantation

Sinusoidal obstruction syndrome (SOS) is a potentially fatal complication of hematopoietic stem cell transplantation (HSCT) initiated through damage of sinusoidal endothelium and inflammation. Insulin-like growth factor-l (IGF-l) maintains and repairs endothelium and intestinal mucosa. We hypothesized that low IGF-l levels may increase the risk of inflammatory complications, such as SOS, in HSCT-patients. We prospectively measured IGF-l concentrations in 121 pediatric patients before, during, and after allogeneic HSCT. Overall, IGF-l levels were significantly reduced compared with healthy sex- and age-matched children. IGF-I levels pre-HSCT and at day 0 were inversely associated with C-reactive protein levels, hyperbilirubinemia, and number of platelet transfusions within the first 21 days post-transplant. Low levels of IGF-I before conditioning and at day of transplant were associated with increased risk of SOS diagnosed by the modified Seattle criteria (pre-HSCT: OR = 1.7 (95% CI: 1.2-2.6, p = 0.01), and the pediatric EBMT criteria (pre-HSCT: 1.7 (1.2-2.5, p = 0.009) and day 0: 1.7 (1.3-2.5, p = 0.001)/SDS decrease in IGF-1). These data suggest that IGF-I is protective against cytotoxic damage and SOS, most likely through trophic effects on endothelial cells and anti-inflammatory properties, and may prove useful as a predictive biomarker of SOS.

Transjugular Intrahepatic Portosystemic Shunt for Very Severe Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome (VOD/SOS) after Unmanipulated Haploidentical Hematopoietic Stem Cell Transplantation with Post-transplantation Cyclophosphamide

Hepatic veno-occlusive disease or sinusoidal obstruction syndrome (VOD/SOS) is a threatening complication after both autologous and allogeneic hematopoietic stem cell transplantation (HSCT), with high mortality rates despite early medical treatment, including the use of defibrotide (DF). We retrospectively analyzed 185 unmanipulated haploidentical (haplo-) HSCT with post-transplantation cyclophosphamide as graft-versus-host disease prophylaxis performed consecutively between 2011 and June 2019 in a single center. Seventeen patients (9.2%) were diagnosed with VOD/SOS. Based on revised European Society for Blood and Marrow Transplantation severity criteria, the VOD/SOS cases were classified as mild in 2 patients (11.7%), moderate in 2 (11.7%), severe in 2 (11.7%), and very severe in 11 (64.9%). Thirteen patients (76%) were treated with DF, including all patients with severe or very severe VOD/SOS, except 1 patient with CNS hemorrhage. Sixteen patients (94%) were alive at day +100 after HSCT. Seven patients (41%) with very severe VOD/SOS were treated with transjugular intrahepatic portosystemic shunt (TIPS) owing to rapid clinical or analytical deterioration or refractory hepatorenal syndrome despite medical treatment, including DF. TIPS insertion was performed at a median time since VOD/SOS diagnosis of 4 days (range, 1 to 28 days) without technical complications in any case. The median hepatic venous pressure gradient before and after TIPS treatment was 24 mmHg (range, 14 to 29 mmHg) and 7 mmHg (range, 2 to 11 mmHg), respectively, with a median drop of 16 mmHg (range, 9 to 19 mmHg). Following TIPS insertion, all patients showed clinical improvement with hepatomegaly, ascites, and renal failure resolution, and all showed analytical improvement with reduced alanine aminotransferase (ALT), creatinine, and international normalized ratio values, except for patient 2, whose indication for TIPS was refractory hepatorenal syndrome with a normal ALT level. The 6 patients who had initiated DF before TIPS insertion completed 21 days of treatment. All patients met the criteria for complete remission (CR) at a median of 8 days after TIPS insertion (range, 2 to 82 days). The 100-day overall survival was 100%. For patients with rapid progressive VOD/SOS, early TIPS insertion allowed completion of DF therapy. The use of TIPS together with DF resulted in CR and no associated complications with no VOD/SOS-associated mortality despite high severity. In our experience, timely and individualized use of TIPS significantly improves outcomes of very severe VOD/SOS after haplo-HSCT. Therefore, TIPS should be promptly considered in rapidly progressive cases.

Defibrotide inhibits donor leucocyte-endothelial interactions and protects against acute graft-versus-host disease

Allogeneic hematopoietic stem cell transplantation (allo‐HCT) is an effective therapy for the treatment of high‐risk haematological malignant disorders and other life‐threatening haematological and genetic diseases. Acute graft‐versus‐host disease (aGvHD) remains the most frequent cause of non‐relapse mortality following allo‐HCT and limits its extensive clinical application. Current pharmacologic agents used for prophylaxis and treatment of aGvHD are not uniformly successful and have serious secondary side effects. Therefore, more effective and safe prophylaxis and therapy for aGvHD are an unmet clinical need. Defibrotide is a multi‐target drug successfully employed for prophylaxis and treatment of veno‐occlusive disease/sinusoidal obstruction syndrome. Recent preliminary clinical data have suggested some efficacy of defibrotide in the prevention of aGvHD after allo‐HCT. Using a fully MHC‐mismatched murine model of allo‐HCT, we report here that defibrotide, either in prophylaxis or treatment, is effective in preventing T cell and neutrophil infiltration and aGvHD‐associated tissue injury, thus reducing aGvHD incidence and severity, with significantly improved survival after allo‐HCT. Moreover, we performed in vitro mechanistic studies using human cells revealing that defibrotide inhibits leucocyte‐endothelial interactions by down‐regulating expression of key endothelial adhesion molecules involved in leucocyte trafficking. Together, these findings provide evidence that defibrotide may represent an effective and safe clinical alternative for both prophylaxis and treatment of aGvHD after allo‐HCT, paving the way for new therapeutic approaches.

Serious Hemorrhagic Complications After Successful Treatment of Hematopoietic Stem Cell Transplantation-Associated Thrombotic Microangiopathy With Defibrotide in Pediatric Patient With Myelodysplastic Syndrome

Background: Transplant-associated thrombotic microangiopathy (TAM) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT). There is some evidence of endothelial injury playing a significant role in TAM development. The efficacy of defibrotide was demonstrated for prophylaxis and treatment of another HSCT-associated endothelial damage syndrome-liver veno-occlusive disease. The data for defibrotide usage in TAM are limited. Case Description: A 9-year old boy underwent HSCT from a matched unrelated donor for monosomy seven-associated myelodysplastic syndrome treatment. A myeloablative preparative regimen and post-transplant immunosuppression with cyclophosphamide on days +3 and +4 and a combination of tacrolimus with mycophenolate mofetil from day +5 were used. From day +61, sustained fever with progressive neurologic impairment and no evidence of infection was observed. On day +68, the patient developed severe TAM with acute kidney injury requiring renal replacement therapy (RRT). Defibrotide therapy 25 mg/kg/day was administered for 7 days with resolution of TAM symptoms. It was followed by multiple hemorrhagic episodes-epistaxis, hemorrhagic cystitis, and renal hemorrhage, which are presumed to be the complications of defibrotide therapy. Conclusion: Defibrotide could be an effective therapy for TAM, but adequate doses, duration of therapy, and drug safety profile both for pediatric and adult patients need to be evaluated by randomized prospective studies.

Diagnosis and Treatment of VOD/SOS After Allogeneic Hematopoietic Stem Cell Transplantation

Hepatic veno-occlusive disease (VOD) or sinusoidal obstruction syndrome (SOS) is a rare complication characterized by hepatomegaly, right-upper quadrant pain, jaundice, and ascites, occurring after high-dose chemotherapy, hematopoietic stem cell transplantation (HSCT) and, less commonly, other conditions. We review pathogenesis, clinical appearance and diagnostic criteria, risk factors, prophylaxis, and treatment of the VOD occurring post-HSCT. The injury of the sinusoidal endothelial cells with loss of wall integrity and sinusoidal obstruction is the basis of development of postsinusoidal portal hypertension responsible for clinical syndrome. Risk factors associated with the onset of VOD and diagnostic tools have been recently updated both in the pediatric and adult settings and here are reported. Treatment includes supportive care, intensive management, and specific drug therapy with defibrotide. Because of its severity, particularly in VOD with associated multiorgan disease, prophylaxis approaches are under investigation. During the last years, decreased mortality associated to VOD/SOS has been reported being it attributable to a better intensive and multidisciplinary approach.

Modified diagnostic criteria, grading classification and newly elucidated pathophysiology of hepatic SOS/VOD after haematopoietic cell transplantation

Sinusoidal obstruction syndrome (SOS), previously known as hepatic veno-occlusive disease (VOD), remains a multi-organ system complication following haematopoietic cell transplantation (HCT). When SOS/VOD is accompanied by multi-organ dysfunction, overall mortality rates remain >80%. However, the definitions related to the diagnosis and grading of SOS/VOD after HCT are almost 25 years old and require new and contemporary modifications. Importantly, the pathophysiology of SOS/VOD, including the contribution of dysregulated inflammatory and coagulation cascades as well as the critical importance of liver and vascular derived endothelial dysfunction, have been elucidated. Here we summarise new information on pathogenesis of SOS/VOD; identify modifiable and unmodifiable risk factors for disease development; propose novel, contemporary and panel opinion-based diagnostic criteria and an innovative organ-based method of SOS/VOD grading classification; and review current approaches for prophylaxis and treatment of SOS/VOD. This review will hopefully illuminate pathways responsible for drug-induced liver injury and manifestations of disease, sharpen awareness of risk for disease development and enhance the timely and correct diagnosis of SOS/VOD post-HCT.

What the Intensivist Needs to Know About Hematopoietic Stem Cell Transplantation?

Hematopoietic stem cell transplantation (HSCT) is a potential curative therapy for some patients with hematologic conditions. There are two main types of HSCT. This includes autologous HSCT, for which the stem cells are obtained from the patient, and allogeneic HSCT, for which the stem cells are obtained from a related or unrelated donor. The most common indications for autologous stem cell transplant are multiple myeloma and relapsed/refractory lymphoma, whereas leukemia and bone marrow failure syndromes remain the most common indications for allogeneic stem cell transplant. This chapter will review the different types, indications, processes, and main complications of HSCT. This chapter will also discuss end-of-life issues that patients and providers face when transplant patients are admitted for the intensive care unit.

Is there a role for immunosuppression in antiphospholipid syndrome?

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombosis, pregnancy morbidity, or nonthrombotic manifestations in patients with persistently positive antiphospholipid antibodies (aPL). Conventional APS treatment focuses on antithrombotic strategies, which are usually ineffective for the microvascular and nonthrombotic manifestations of aPL. Using a case-based presentation, this review focuses on the role of immunosuppression in nonobstetric APS, including B-cell inhibition (rituximab, belimumab, and bortezomib), complement inhibition (eculizumab), mechanistic target of rapamycin inhibition (sirolimus), vascular endothelial cell modulation (defibrotide), statins, and traditional rheumatologic disease-modifying agents (hydroxychloroquine, mycophenolate mofetil, azathioprine, and cyclophosphamide).

Defibrotide for the treatment of severe hepatic sinusoidal obstruction syndrome: a single-centre experience

Objectives

Determine the effectiveness and cost of defibrotide in patients with severe hepatic sinusoidal obstruction syndrome following haematopoietic stem cell transplantation in a tertiary hospital.

Methods

A retrospective observational study. Adults or children treated with defibrotide at a mean dose of 6.8 mg/kg every 6 hours, until the total bilirubin levels are normalised, were included. Main endpoint was complete response, defined as normalised total serum bilirubin levels and resolution of multiple organ failure. Secondary endpoints were survival by 100 days post-transplant, influence of risks factors in effectiveness and cost of treatment.

Results

51 patients (36 adults and 15 children) received defibrotide; median dose of defibrotide administered was 25.19 mg/kg/day (10.0-100.3). Complete response was achieved in 19 (37.3%) patients. By 100 days post-transplant complete response was achieved in 18 (35.3%) patients and the survival rate was 29 (56.9%) patients. There were no significant differences in effectiveness between adults versus paediatrics and between patients who presented risk factors. The mean cost of treatment per patient was €32 916, mean costs in adults was €104 292 and €17 394 in children.

Conclusion

Regarding the results of our study, it is convenient to identify the patients who will be able to benefit from this treatment according to clinical conditions, medical history and prognosis. Given the great economic impact of defibrotide, we consider that more cost-effectiveness studies are required.

Trial registration number

EPA-OD, number LBM-DEF-2016-01.

Systematic review of defibrotide studies in the treatment of veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS)

Veno-occlusive disease (VOD), also called sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT) conditioning or high-dose nontransplant chemotherapy. VOD/SOS with multi-organ dysfunction (MOD) is associated with a mortality rate of > 80%. Defibrotide (25 mg/kg/day) is approved to treat hepatic VOD/SOS with renal or pulmonary dysfunction post HSCT in the United States and to treat severe hepatic VOD/SOS in patients > 1 month of age in the European Union. A random effects model was used for pooling data from 17 systematically chosen defibrotide studies. For patients in these reports (n = 2598), and those in the subset of 10 reports of patients treated with ~ 25 mg/kg/day (n = 1691), estimated Day + 100 survival rates were 54% and 56%, respectively. Among those patients treated with ~ 25 mg/kg/day, estimated Day + 100 survival was 44% among patients with MOD and 71% in patients without MOD; survival was 41% and 70%, respectively, for the population of patients receiving any dose of defibrotide. Safety results were not pooled owing to differences in reporting methodology but were generally consistent with the known tolerability profile of defibrotide. This analysis provides the largest assessment of survival in patients treated with defibrotide for VOD/SOS with or without MOD.

Publisher Correction: Systematic review of defibrotide studies in the treatment of veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS)

The original version of this article included some minor typesetting errors in Table 1-a corrected version of which is provided in this correction article and has been corrected in the original article-and one error in text, which has been corrected in the original article. Furthermore, the article was erroneously published with the copyright holders as 'Springer Nature Limited', however, since the article is Open Access, the copyright holders should in fact be 'The Author(s)'. This has also been corrected in the original article.

Hepatic Sinusoidal Obstruction Syndrome in a Patient With Multiple Myeloma Treated With CyBorD

Hepatic sinusoidal obstruction syndrome (SOS) is a life-threatening state generally occurring as a complication of conditioning regimens used for hematopoietic stem cell transplant. Hepatic SOS after a standard dose of chemotherapy in malignancies is rare, and there are only a few cases in pediatric literature. We report a 56-year-old man with multiple myeloma who experienced SOS after being initiated on chemotherapy including cyclophosphamide, dexamethasone, and bortezomib and who experienced a delay in treatment with defibrotide, because it is currently approved by the Food and Drug Administration for only patients who develop SOS after hematopoietic stem cell transplant.

Prophylactic, preemptive, and curative treatment for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a position statement from an international expert group

Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation (HCT). While SOS/VOD may resolve within a few weeks in the majority of patients with mild-to-moderate disease, the most severe forms result in multiorgan dysfunction and are associated with a high mortality rate (>80%). Therefore, careful surveillance may allow early detection of SOS/VOD, particularly as the licensed available drug is proven to be effective and reduce mortality. The aim of this work is to propose an international consensus guideline for the treatment and prevention of SOS/VOD in adult patients, on behalf of an international expert group.

Current approach to early gastrointestinal and liver complications of hematopoietic stem cell transplantation

The gastrointestinal (GI) system is one of the most commonly affected sites during a hematopoietic stem cell transplantation (HSCT) due to toxicities of preparative regimens, the accompanying immunodeficiency, and organ damage caused by graft versus host disease. In this review, we focus on early GI and liver complications following autologous (auto-) and allogeneic (allo-) HSCT and clarify both the risk factors and therapeutic strategies. Early GI and liver complications associated with HSCT remain challenging issues. Despite the improvements in this field during the last decade, treatments for these complications still place a significant burden on both patients and the physicians treating these patients. GI and liver complications remain some of the causes of mortality associated with HSCT. For practicing hematologists, oncologists, and gastroenterologists in this field, the awareness and early diagnosis of the GI complications remain important factors to obtain optimal outcomes in this patient population.

The use of defibrotide in blood and marrow transplantation

Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of conditioning during hematopoietic stem cell transplantation (HSCT) or chemotherapy without HSCT, with a historically reported mean incidence of 13.7% post-HSCT. Typical symptoms of VOD/SOS may include hyperbilirubinemia, painful hepatomegaly, weight gain, and ascites. Defibrotide, a polydisperse mixture of predominantly single-stranded polydeoxyribonucleotides, is currently the only therapy approved to treat hepatic VOD/SOS with pulmonary/renal dysfunction (ie, multiorgan dysfunction/multiorgan failure [MOD/MOF]) following HSCT in the United States and to treat severe hepatic VOD/SOS post-HSCT in the European Union. In preclinical and human studies, defibrotide has demonstrated profibrinolytic, antithrombotic, anti-inflammatory, and angio-protective actions, thus promoting an anticoagulant phenotype of the endothelium that protects and stabilizes the function of endothelial cells. In a phase 3, historically controlled, multicenter trial in adults and children with VOD/SOS and MOD/MOF (defibrotide: n = 102; controls treated before defibrotide availability: n = 32), defibrotide resulted in significantly greater day +100 survival following HSCT (38.2%) vs controls (25.0%; propensity analysis-estimated between-group difference: 23%; P = .0109). The most common adverse events (AEs) were hypotension and diarrhea; rates of common hemorrhagic AEs were similar in the defibrotide and historical control group (64% and 75%, respectively). In a phase 3 prophylaxis trial, defibrotide was found to lower incidence of VOD/SOS in children (not an approved indication) and reduce the incidence of graft-versus-host disease. This review describes the development and clinical applications of defibrotide, focusing on its on-label use in patients with VOD/SOS and MOD/MOF after HSCT.

Treatment of hepatic veno-occlusive disease in children with N-acetylcysteine

In our institution, hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) has been treated with N-acetylcysteine (NAC) since 2008-a loading dose of 150 mg/kg, followed by 12 doses of 70 mg/kg 6 hourly. Nine children were diagnosed with hepatic VOD/SOS. Hepatic VOD/SOS occurred in seven children after stem cell transplantation and two were receiving chemotherapy for Wilms tumor. Their clinical severity was classified as moderate in two and severe in seven by the European Society for Blood and Marrow Transplantation criteria. All children recovered and were discharged from 4 to 16 days after diagnosis. No side effects were observed. Intravenous NAC is an effective treatment for hepatic VOD/SOS.

Assessment of the proposed EBMT pediatric criteria for diagnosis and severity grading of sinusoidal obstruction syndrome

Sinusoidal obstruction syndrome (SOS) is a potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT). We assessed the proposed pediatric EBMT criteria along with the Baltimore and modified Seattle criteria in a population-based cohort. Eighty-seven children (1.1–17.3 years) undergoing myeloablative HSCT from 2010 to 2017 were consecutively included at the Danish National Transplantation Center. In total, 39 (44.8%) patients fulfilled the EBMT criteria and 30 patients (35%) fulfilled the criteria for severe or very severe SOS. Nine (10.3%) patients fulfilled the modified Seattle criteria while none met the Baltimore criteria. Patients fulfilling the EBMT criteria for SOS had longer primary admission (31 days (23–183) vs. 27 days (17–61), p = 0.001), were treated more intensively with diuretics within the first 3 months (29 days (0–90) vs. 3.5 days (0–90), p < 0.0001), and had a longer time to stable platelet counts >50 × 10⁹/L (32 days (16–183) vs. 23 days (14–101), p < 0.0001). Two patients, fulfilling neither Baltimore nor Seattle criteria, but selectively fulfilling EBMT criteria, died of treatment-related acute inflammatory complications within 1 year post-HSCT. In conclusion, application of the pediatric EBMT diagnostic and severity criteria may be helpful in identifying patients at increased risk of severe treatment-related complications and mortality, although with a risk of over-diagnosing SOS.

New Ultrasound Techniques Challenge the Diagnosis of Sinusoidal Obstruction Syndrome

Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation. Clinically, SOS/VOD is characterized by hepatomegaly, right upper quadrant pain, jaundice and ascites, most often occurring within the first 3 wk after hematopoietic cell transplantation. Early therapeutic intervention is pivotal for survival in SOS/VOD. Thus, a rapid and reliable diagnosis has to be made. Diagnosis of SOS/VOD is based on clinical criteria, such as the Seattle, Baltimore or recently issued European Society for Blood and Marrow Transplantation criteria, to which hemodynamic and/or ultrasound evidence of SOS were added for the first time. However, to rule out major differential diagnoses and to verify the diagnosis, a reliable imaging method is needed. Ultrasound techniques have been proposed in SOS/VOD. Nevertheless, the sensitivity and specificity of transabdominal ultrasound and Doppler techniques need to be improved. Innovative ultrasound methods such as a combination of Doppler ultrasound with shear wave elastography and contrast-enhanced ultrasound techniques should be evaluated for diagnosis and follow-up of SOS/VOD. The goals of this review are to discuss currently available ultrasound techniques and to identify areas for future studies in SOS/VOD.