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Effectiveness of defibrotide in the prevention of hepatic venooclusive disease among adult patients receiving allogeneic hematopoietic cell transplantation: A retrospective single center experience
Abstract
Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is one of the most life-threatening early complications following hematopoietic cell transplantation (HCT). Due to the high mortality rate of severe VOD/SOS accompanied with multiorgan failure, there is a great interest in preventive strategies. The efficacy of defibrotide (DF) on the prevention of VOD/SOS has been clearly shown in high-risk pediatric patients, but evidence-based data on adults is scarce. In this report, we aimed to assess the impact of DF on the incidence of VOD/SOS in our center by posttransplant day 30 among patients who were treated with allogeneic HCT (allo-HCT). The study included a total of 56 patiens (28 males, 28 females). The median age of the study cohort was 43 (20-68). The daily dose of DF was 10 mg/kg and 25 mg/kg in 53 (94.6%) and 3 (5.3%) patients, respectively. Patients also recieved oral ursodeoxycolic acid (UDCA) 250 mg three-times daily started with conditioning until D + 90. Twenty-three (41.1%) patients had at least one major EBMT-defined risk factor for development of VOD/SOS. One patient who belonged to a very high-risk group (with at least two major risk factors) developed very-severe VOD/SOS at posttransplant D + 20 and died as a result of multiorgan failure. The cumulative incidence of VOD/SOS at D + 30 was 1.9%. Our findings indicate that 10 mg/kg daily intravenous DF combined with UDCA is quite effective in prevention of VOD/SOS in patients who underwent first allo-HSCT.
... The inter-study variance may be due to the different dosing regimens used (including occasional co-medication with UDCA) and different intervals between diagnosis and DF treatment initiation. Greater success has been reported using initiating DF earlier [128] after SOS diagnosis or combining it with UDCA [129]. ...
Danaparoid sodium is an antithrombotic isolated from porcine mucosa. Its main constituent is a mixture of heparan sulphates that inhibits thrombin generation and also possesses anti-inflammatory and immune-modulatory activity. It has shown safety and efficacy in its main indications of deep venous thrombosis prophylaxis, heparin-induced thrombocytopenia treatment and disseminated intravascular thrombosis treatment. In addition, there are reports of its off-label use for the treatment of portal vein thrombosis in adults and for prevention of the hepatic thrombotic microangiopathies haematogenous that complicate recovery after stem cell transplantation in adults and children. The results of these studies provide further support for its safety and efficacy even in subjects with cirrhosis and/or severe hepatic dysfunction. In this chapter the rationale for danaparoid use is presented and the collated results of comparative studies and case reports are compared with those of other pharmaceutical options for managing these hepatic thrombotic disorders.
This work aims to review the role of endothelial dysfunction underlying the main complications appearing early after autologous and allogeneic hematopoietic cell transplantation (HCT). The endothelial damage as the pathophysiological substrate of sinusoidal obstruction syndrome (SOS) is well established. However, there is growing evidence of the involvement of endothelial dysfunction in other complications, such as acute graft-versus-host disease (aGVHD) and transplant-associated thrombotic microangiopathy (TA-TMAs). Moreover, HCT-related endotheliopathy is not only limited to the HCT setting, as there is increasing evidence of its implication in complications derived from other cellular therapies. We also review the incidence and the risk factors of the main HCT complications and the biological evidence of the endothelial involvement and other linked pathways in their development. In addition, we cover the state of the art regarding the potential use of the biomarkers of endotheliopathy in the prediction, the early diagnosis, and the follow-up of the HCT complications and summarize current knowledge points to the endothelium and the other linked pathways described as potential targets for the prevention and treatment of HCT-complications. Lastly, the endothelium-focused therapeutic strategies that are emerging and might have a potential impact on the survival and quality of life of post-HCT-patients are additionally reviewed.
Use of haematopoietic cell transplantation (HCT) in the treatment of haematologic and neoplastic diseases may lead to life‐threatening complications that cause substantial morbidity and mortality if untreated. In addition to patient‐ and disease‐related factors, toxicity associated with HCT puts patients at risk for complications that share a similar pathophysiology involving endothelial cells (ECs). Normally, the endothelium plays a role in maintaining homeostasis, including regulation of coagulation, vascular tone, permeability and inflammatory processes. When activated, ECs acquire cellular features that may lead to phenotypic changes that induce procoagulant, pro‐inflammatory and pro‐apoptotic mediators leading to EC dysfunction and damage. Elevated levels of coagulation factors, cytokines and adhesion molecules are indicative of endothelial dysfunction, and endothelial damage may lead to clinical signs and symptoms of pathological post‐HCT conditions, including veno‐occlusive disease/sinusoidal obstruction syndrome, graft‐versus‐host disease, transplant‐associated thrombotic microangiopathy and idiopathic pneumonia syndrome/diffuse alveolar haemorrhage. The endothelium represents a rational target for preventing and treating HCT complications arising from EC dysfunction and damage. Additionally, markers of endothelial damage may be useful in improving diagnosis of HCT‐related complications and monitoring treatment effect. Continued research to effectively manage EC activation, injury and dysfunction may be important in improving patient outcomes after HCT.
To address limitations of the currently used reduced-intensity/myeloablative conditioning (RIC/MAC) classification scheme we aimed to develop a tool that can capture more standardized the conditioning intensity of allogeneic hematopoietic cell transplantation (HCT). We assigned intensity weight scores for frequently used conditioning regimen components and used their sum to generate the transplant conditioning intensity (TCI) score. We retrospectively tested the impact of TCI on 8255 adult (45–65 years) acute myeloid leukemia patients who underwent HCT in first complete remission. A Cox model for early nonrelapse mortality (NRM) yielded a 3-group TCI risk scheme (low, intermediate, high) with respective TCI scores of [1–2], [2.5–3.5] and [4–6]. On multivariate modeling, TCI grouping was highly and better predictive for early (day 100 and 180) NRM, 2-year NRM and relapse (REL) as compared with the RIC/MAC classification. Validation was done on 200 bootstrap samples. Moreover, TCI scoring enabled the identification of a distinct subgroup of RIC and MAC conditioning regimens with an intermediate TCI [2.5–3.5] score that had identical outcomes and which are frequently referred as “reduced toxicity conditioning”. TCI scheme provides an improvement of the RIC/MAC classification. We propose TCI as a new tool to define and measure the conditioning regimen intensity.
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.
Background:
A risk score identifying patients at high risk for veno-occlusive disease (VOD) may aid efforts to study preventive strategies for this uncommon complication of hematopoietic cell transplantation (HCT).
Methods:
Patients receiving a first allogeneic HCT between 2008-2013 as reported to the Center for International Blood & Marrow Transplant Research (N=13,097) were randomly divided into training and validation sets. Independent prognostic factors for development of VOD by day+100 post HCT were identified with a multivariate logistic regression model. A risk score was constructed in the training set using the significant factors and confirmed in the validation set.
Results:
Baseline characteristics of the training and validation sets were balanced. In total, 637 patients (4.9%) developed VOD by day+100. Younger age, positive hepatitis B/C serology (HBV, HCV), lower Karnofsky performance score (KPS), use of sirolimus, disease, disease status at transplant, and conditioning regimen were independent prognostic factors. Myeloablative (MAC) regimens were associated with higher risk of VOD. Busulfan-based MAC regimens guided by pharmacokinetic monitoring (PK) were associated with higher risk than those without PK. The patients were stratified into 4 distinct, statistically significantly different groups by their risk score percentile.
Conclusion:
This pre-transplant risk score successfully stratified allogeneic HCT patients by risk of developing VOD, was validated in an independent set, and demonstrated strong discriminatory ability to identify a high-risk cohort.
Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life threatening complication that can develop after hematopoietic cell transplantation. Although SOS/VOD progressively resolves within a few weeks in most patients, the most severe forms result in multi-organ dysfunction and are associated with a high mortality rate (>80%). Therefore, careful attention must be paid to allow an early detection of SOS/VOD, particularly as drugs have now proven to be effective and licensed for its treatment. Unfortunately, current criteria lack sensitivity and specificity, making early identification and severity assessment of SOS/VOD difficult. The aim of this work is to propose a new definition for diagnosis, and a severity-grading system for SOS/VOD in adult patients, on behalf of the European Society for Blood and Marrow Transplantation.Bone Marrow Transplantation advance online publication, 16 May 2016; doi:10.1038/bmt.2016.130.
Veno-occlusive disease (VOD) is an early and serious complication of hematopoietic cell transplantation (HCT) that is associated with inferior survival, particularly when it is complicated by multi-organ failure (severe VOD). We evaluated the efficacy of defibrotide in the treatment of severe VOD using observational data from the Center for International Blood and Marrow Transplant Research (CIBMTR). Eight thousand three hundred forty-one patients treated by HCT between 2008 and 2011 were identified from the CIBMTR clinical database; 3.2% met criteria for VOD and 1.2% met criteria for severe VOD. Patients with a diagnosis of VOD as reported to the CIBMTR by their transplanting centers, who had no prior history of cirrhosis, and who had a maximum total bilirubin >2.0mg/dl by day +100 post-HCT were selected for study. Severe VOD was defined as VOD occurring in the setting of renal impairment requiring dialysis or any non-infectious pulmonary abnormality. Patients with severe VOD were divided into two groups for analysis: those treated with defibrotide (n=41) and those not treated with defibrotide (n=55). Patients in the non-defibrotide group were older, were more likely to be male, were more likely to have a history of previous fungal infection, and had a higher proportion of clinically significant pre-existing disease or organ impairment. Survival at day +100 was 39% (95% CI: 24.8-54.3%) in patients receiving defibrotide and 30.9% (95% CI: 19.5% - 43.6%) in those not receiving defibrotide. Resolution of VOD at day +100 was 51% in the defibrotide group, and 29% in the non-defibrotide group (difference 22.1%, 95% CI: 2.6% - 42%). The results of our study are consistent with previously reported experiences with defibrotide, confirm the poor outcome of this syndrome, and suggest defibrotide is effective in the treatment of severe VOD.
Purpose:
Age has long been used as a major factor for assessing suitability for allogeneic hematopoietic cell transplantation (HCT). The HCT-comorbidity index (HCT-CI) was developed as a measure of health status to predict mortality risk after HCT. Whether age, comorbidities, or both should guide decision making for HCT is unknown.
Patients and methods:
Data from 3,033 consecutive recipients of HLA-matched grafts from five institutions contributed to this analysis. Patients were randomly divided into a training set to develop weights for age intervals and a validation set to assess the performance of prognostic models.
Results:
In the training set, patients age 20 to 39 years, 40 to 49 years, 50 to 59 years, and ≥ 60 years had hazard ratios for nonrelapse mortality (NRM) of 1.21 (P = .29), 1.48 (P = .04), 1.75 (P = .004), and 1.84 (P = .005), respectively, compared with those age younger than 20 years. Consequently, age ≥ 40 years was assigned a weight of 1 to be added to the HCT-CI to constitute a composite comorbidity/age index. In the validation set, the composite comorbidity/age score had statistically significantly higher c-statistic estimates for prediction of NRM (0.664 v 0.556; P < .001) and survival (0.682 v 0.560; P < .001) compared with age, respectively. Patients with comorbidity/age scores of 0 to 2 had comparable mortality risks regardless of conditioning regimens. Patients with scores of 3 to 4 and ≥ 5 had statistically significant higher mortality risks after high-dose versus nonmyeloablative regimens.
Conclusion:
Age is a poor prognostic factor. The proposed composite measure allows integration of both comorbidities and age into clinical decision making and comparative-effectiveness research of HCT.
Because the outcome of allogeneic hematopoietic cell transplantation (HCT) is predominantly influenced by disease type and status, it is essential to be able to stratify patients undergoing HCT by disease risk. The Disease Risk Index (DRI) was developed for this purpose. In this study, we analyzed 13,131 patients reported to the Center for International Blood and Marrow Transplant Research who underwent HCT between 2008 and 2010. The DRI stratified patients into 4 groups with 2-year overall survival (OS) ranging from 64% to 24% and was the strongest prognostic factor, regardless of age, conditioning intensity, graft source, or donor type. A randomly selected training subgroup of 9849 patients was used to refine the DRI, using a multivariable regression model for OS. This refined DRI had improved prediction ability for the remaining 3282 patients compared with the original DRI or other existing schemes. This validated and refined DRI can be used as a 4- or 3-group index, depending on the size of the cohort under study, for prognostication; to facilitate the interpretation of single-center, multicenter, or registry studies; to adjust center outcome data; and to stratify patients entering clinical trials that enroll patients across disease categories.
Hepatic veno-occlusive disease is a leading cause of morbidity and mortality after haemopoietic stem-cell transplantation (HSCT). We aimed to assess whether defibrotide can reduce the incidence of veno-occlusive disease in this setting.
In our phase 3 open-label, randomised controlled trial, we enrolled patients at 28 European university hospitals or academic medical centres. Eligible patients were younger than 18 years, had undergone myeloablative conditioning before allogeneic or autologous HSCT, and had one or more risk factor for veno-occlusive disease based on modified Seattle criteria. We centrally assigned eligible participants on the basis of a computer-generated randomisation sequence (1:1), stratified by centre and presence of osteopetrosis, to receive intravenous defibrotide prophylaxis (treatment group) or not (control group). The primary endpoint was incidence of veno-occlusive disease by 30 days after HSCT, adjudicated by a masked, independent review committee, in eligible patients who consented to randomisation (intention-to-treat population), and was assessed with a competing risk approach. Patients in either group who developed veno-occlusive disease received defibrotide for treatment. We assessed adverse events to 180 days after HSCT in all patients who received allocated prophylaxis. This trial is registered with ClinicalTrials.gov, number NCT00272948.
Between Jan 25, 2006, and Jan 29, 2009, we enrolled 356 eligible patients to the intention-to-treat population. 22 (12%) of 180 patients randomly allocated to the defibrotide group had veno-occlusive disease by 30 days after HSCT compared with 35 (20%) of 176 controls (risk difference -7·7%, 95% CI -15·3 to -0·1; Z test for competing risk analysis p=0·0488; log-rank test p=0·0507). 154 (87%) of 177 patients in the defibrotide group had adverse events by day 180 compared with 155 (88%) of 176 controls.
Defibrotide prophylaxis seems to reduce incidence of veno-occlusive disease and is well tolerated. Thus, such prophylaxis could present a useful clinical option for this serious complication of HSCT.
Gentium SpA, European Group for Blood and Marrow Transplantation.
Defining conditioning regimen intensity has become a critical issue for the hemopoietic stem cell transplant (HSCT) community. In the present report we propose to define conditioning regimens in 3 categories: (1) myeloablative (MA) conditioning, (2) reduced-intensity conditioning (RIC), and (3) nonmyeloablative (NMA) conditioning. Assignment to these categories is based on the duration of cytopenia and on the requirement for stem cell (SC) support: MA regimens cause irreversible cytopenia and SC support is mandatory. NMA regimens cause minimal cytopenia, and can be given also without SC support. RIC regimens do not fit criteria for MA or NMA regimens: they cause cytopenia of variable duration, and should be given with stem cell support, although cytopenia may not be irreversible. This report also assigns commonly used regimens to one of these categories, based upon the agents, dose, or combinations. Standardized classification of conditioning regimen intensities will allow comparison across studies and interpretation of study results.
Veno-occlusive disease (VOD) of the liver occurs in 10% to 50% of patients after allogeneic stem cell transplantation, ranging from mild reversible disease to severe disease, with a mortality rate almost always close to 100%. Recently, promising results in the treatment of established VOD with defibrotide were reported. Therefore, defibrotide may be used as a prophylactic regimen for hepatic VOD in stem cell transplantation for hematologic malignancies. Fifty-two successive patients who underwent transplantation between October 1999 and June 2002 received defibrotide prophylaxis intravenously from day -7 to day +20 after transplantation in addition to heparin and were compared with historical controls who underwent transplantation successively between February 1997 and September 1999. In the defibrotide group, the maximum total bilirubin levels and the number of patients with serum levels exceeding 50 micromol/L were significantly lower than in the control group (5 of 52 versus 18 of 52, respectively; P =.004). None of the 52 patients developed VOD (Baltimore criteria), and no side effects occurred. These results were significantly different (P =.001) from controls (10/52 [19%] with VOD, 3 of whom died of severe VOD). In addition, day 100 event-free survival was significantly higher in the study group (P =.02), with a trend toward better day 100 overall survival (P =.07). These results suggest that defibrotide given in addition to heparin may be an efficient prophylaxis for VOD.
We previously reported that the Charlson Comorbidity Index (CCI) was useful for predicting outcomes in patients undergoing allogeneic hematopoietic cell transplantation (HCT). However, the sample size of patients with scores of 1 or more, captured by the CCI, did not exceed 35%. Further, some comorbidities were rarely found among patients who underwent HCT. Therefore, the current study was designed to (1) better define previously identified comorbidities using pretransplant laboratory data, (2) investigate additional HCT-related comorbidities, and (3) establish comorbidity scores that were suited for HCT. Data were collected from 1055 patients, and then randomly divided into training and validation sets. Weights were assigned to individual comorbidities according to their prognostic significance in Cox proportional hazard models. The new index was then validated. The new index proved to be more sensitive than the CCI since it captured 62% of patients with scores more than 0 compared with 12%, respectively. Further, the new index showed better survival prediction than the CCI (likelihood ratio of 23.7 versus 7.1 and c statistics of 0.661 versus 0.561, respectively, P < .001). In conclusion, the new simple index provided valid and reliable scoring of pretransplant comorbidities that predicted nonrelapse mortality and survival. This index will be useful for clinical trials and patient counseling before HCT.
Hepatic veno-occlusive disease (HVOD) is a serious life-threatening complication of hematopoietic stem cell transplantation (HSCT). Currently, there is no optimal therapeutic strategy and preventive measures are ill-defined. Ursodeoxycholic acid (UA) is well-tolerated oral medication that has been associated with possible benefit as a prophylactic agent. We sought to summarize and quantify the clinical effects of prophylactic UA in the context of HSCT. We undertook a systematic review of studies addressing the use of UA as monotherapy or in combination with other agents in patients undergoing HSCT. The Search Strategy included MEDLINE (1966 to fourth week of March 2006), EMBASE (1980 to fourth week of March 2006), all EBM Reviews (fourth quarter of 2005), Ovid Healthstar (1966 to fourth week of March 2006), and Google Scholar on March 20, 2006. Six studies, 4 randomized clinical trials and 2 historically controlled studies, representing 824 patients were included in the review. Three randomized clinical trials comparing prophylactic UA with no treatment demonstrated reduced proportion of HVOD (relative risk [RR], 0.34; 95% confidence interval [CI], 0.17-0.66). When the analysis was limited to higher-quality studies, the beneficial effect of UA remained significant (RR, 0.36; 95% CI, 0.15-0.90). Transplant-related mortality was also reduced with the prophylactic use of UA (RR, 0.58; 95% CI, 0.35-0.95). UA did not significantly attenuate the outcomes of acute graft-versus-host disease (RR, 0.76; 95% CI, 0.53-1.09), relapse (RR, 0.77; 95% CI, 0.46-1.31), or overall survival (RR, 1.22; 95 % CI, 0.96-1.54). UA appears effective for HVOD prophylaxis in patients undergoing HSCT and should be considered as a prevention strategy by HSCT centers to reduce HVOD.
Veno-occlusive disease (VOD) is a common and high-risk complication of allogeneic stem cell transplantation (SCT). Defibrotide has recently been used successfully to treat the disorder. We report on 58 patients who received defibrotide prophylaxis without concurrent heparin. No patients fulfilled the Baltimore criteria for VOD or died of the condition within 100 days of SCT. None of this group developed haemorrhagic complications secondary to defibrotide. These observations suggest that prophylaxis with defibrotide alone may reduce the incidence of VOD post-SCT although a randomised controlled trial is warranted to further evaluate its role.
Background:
Now there are no efficient prophylactic or treatment strategies for hepatic veno-occlusive disease (VOD). Therefore, it is critical to early identify patients at high risk of VOD.
Aim:
To analyze the risk factors of VOD in the hematopoietic stem cell transplantation (HSCT) patients.
Methods:
A comprehensive search of the population was conducted.
Results:
Twenty-one studies with 27 679 HSCT patients were eligible. The incidence of VOD was 15% [95% confidence interval (CI) 13-17%]. The following were the risk factors for VOD: mismatched HLA [odds ratio (OR) 2.34, 95% CI 1.20-4.57, P = 0.01], history of liver disease (OR 2.72, 95% CI 2.03-3.64, P < 0.00001), elevated AST before transplant (OR 2.49, 95% CI 1.49-4.15, P = 0.0005), months from diagnosis to HSCT > 12 months (OR 1.76, 95% CI 1.15-2.69, P = 0.009), previous radiation (OR 1.86, 95% CI 1.49-2.31, P < 0.00001), busulphan (OR 3.69, 95% CI 2.58-5.29, P < 0.00001) and MTX (OR 1.81, 95% CI 1.22-2.69, P = 0.003). There were no significant differences for VOD presentation in the patients with regards to sex, number of HSCT, Karnofsky score <90%, unrelated donor, autologous HSCT, CYA and heparin prophylaxis.
Conclusion:
Mismatched HLA, liver disease (history of liver disease, elevated AST), months from diagnosis to HSCT >12 months, previous radiation and use of hepatotoxic drugs (BU and MTX) are the independent risk factors for VOD in the HSCT patients.
Hepatic sinusoidal obstruction syndrome (HSOS) is a potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively evaluated the incidence, risk factors, treatment and survival for HSOS after allo-HSCT in Turkey. We also reported our experience of defibrotide (DF) for HSOS prophylaxis in high-risk (HR) patients. Across Turkey, 1153 patients from 10 centers were enrolled in the study. We evaluated the medical records of patients who were treated with allo-SCT between January 2012 and December 2015. The study included 1153 patients (687 males/466 females) with median age of 38 (15-71) years. The incidence of HSOS was 7.5% (n = 86). The incidences of HSOS in the HR/DF+, HR/DF- and standard risk (SR) group were 8%, 66.7% and 6.2%, respectively. The rate of HSOS development was not statistically different between HR/DF + and SR group (p = 0.237). HSOS prophylaxis (defibrotide) was significantly decreased HSOS-related mortality (p = 0.004). The incidence of HSOS was found similar to literature in this large Turkish cohort. Defibrotide prophylaxis appears to be associated with low incidence of HSOS development and reduced HSOS-related mortality. Although these results are promising, future studies are needed to support the efficacy of defibrotide prophylaxis in patients with risk of HSOS.
Introduction: Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is an unpredictable condition associated with endothelial-cell damage due to conditioning for hematopoietic stem-cell transplantation (HSCT) or chemotherapy without HSCT. Mortality in patients with VOD/SOS and multi-organ dysfunction (MOD) may be >80%.
Areas covered: Defibrotide is the only approved drug for the treatment of severe hepatic VOD/SOS after HSCT in the European Union and hepatic VOD/SOS with renal or pulmonary dysfunction in the United States. Its efficacy in patients with VOD/SOS with MOD post-HSCT was demonstrated in a clinical-trial program that included a historically controlled treatment study, a phase 2 trial, and a large T-IND expanded-access program that also included patients without MOD and who received chemotherapy without HSCT.
Expert commentary: Defibrotide appears to protect endothelial cells and restore the thrombolytic–fibrinolytic balance. It addresses a significant clinical need and has demonstrated favorable Day +100 survival and overall adverse-event rates that seem similar to control groups receiving supportive care alone. Currently, defibrotide is under investigation for the prevention of VOD/SOS in high-risk pediatric and adult patients.
Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) of the liver is a serious, early complication of haematopoietic stem cell transplantation (HSCT), severe and very severe forms of which are associated with a high mortality rate. A wide variety of patient, disease and treatment-related risk factors for VOD/SOS have been identified. Several bodies have published recommendations for the diagnosis, prevention and management of VOD/SOS following HSCT. A group of regional experts have developed a consensus statement on the diagnosis, prevention and management of VOD/SOS in the Middle East and North Africa region to help in the management of HSCT patients in the region. Risk factors of particular relevance in the region include iron overload in thalassaemia patients, some hereditary metabolic disorders due to consanguinity and infection with hepatitis virus B or C. Recommendations include diagnosis of VOD/SOS based on established clinical criteria, prophylaxis with defibrotide and/or ursodeoxycholic acid in patients at increased risk of VOD/SOS, and treatment with defibrotide for patients with severe/very severe VOD/SOS (and, if clinically indicated, in those with moderate or rapidly progressing VOD/SOS, as per the new European Society for Blood and Marrow Transplantation classification).
Prophylactic use of defibrotide (DF) to prevent veno-occlusive disease (VOD), a relatively common and high-risk complication of hematopoietic stem cell transplantation (HSCT), may be an encouraging modality to reduce morbidity and mortality from VOD. However, conclusions remain unclear. We carried out a systematic review to summarize the state of knowledge. One randomized controlled trial (RCT), four cohort studies and eight case series studies were found, including a total of 1230 patients. The overall mean incidence of VOD in patients using DF was 4.7% (95% CI, 3.3-6.1) which was significantly lower than the data 13.7% (95% CI, 13.3-14.1) across 135 studies using no VOD prophylaxis (p < 0.005). The meta-analysis of the incidence of VOD in controlled trials revealed a statistical reduction in VOD incidence in the DF group (RR = 0.47, 95% CI, 0.31-0.73). The overall mean incidence of severe VOD was 0.8% (95% CI, 0.2-1.4). The RR was 0.31 (95% CI, 0.09-1.06). However, the lack of RCTs and the methodological weaknesses of the studies may preclude making generalizable conclusions. Our review described that DF appears promising for VOD prevention and large RCT is needed for further confirmation.
Hepatic veno-occlusive disease (VOD) is a common complication of haematopoietic stem cell transplantation (HSCT), with reported incidences of 5-40% in children. Recently, defibrotide (DF) has been successfully used as prophylaxis and treatment of VOD. This study reports data on 63 human leucocyte antigen-matched HSCT performed in 57 children affected by beta thalassemia at very high risk for developing VOD (liver fibrosis, iron overload, hepatitis C virus infections, busulphan-based conditioning, methotraexate + ciclosporine). All patients received a busulphan-based conditioning regimen, either orally (four HSCT) or intravenously (59 HSCT). All patients received oral DF (40 mg/kg per day, final dose) as VOD prophylaxis from median day -9 to median day +29. In order to overcome the lack of oral paediatric formulations, a galenic formulation was administered. DF was well tolerated. Only one patient fulfilled Seattle Criteria for VOD diagnosis. This patient had discontinued DF 6 d prior to VOD onset, due to high risk of haemorrhage. We concluded that oral defibrotide prophylaxis and i.v. busulphan safely abated VOD incidence in high-risk patients who had undergone HSCT. A galenic preparation of oral DF also permits this treatment in low-weight patients. Costs of DF prophylaxis are acceptable considering the reduced incidence of VOD.