Prevention and treatment of veno-occlusive disease

Recent advances in use of fresh frozen plasma, cryoprecipitate, immunoglobulins, and clotting factors for transfusion support in patients with hematologic disease

Hematologic diseases include a broad range of acquired and congenital disorders, many of which affect plasma proteins that control hemostasis and immune responses. Therapeutic interventions for these disorders include transfusion of plasma, cryoprecipitate, immunoglobulins, or convalescent plasma-containing therapeutic antibodies from patients recovering from infectious diseases, as well as concentrated pro- or anticoagulant factors. This review will focus on recent advances in the uses of plasma and its derivatives for patients with acquired and congenital hematologic disorders.

Brazilian Nutritional Consensus in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease

The Brazilian Consensus on Nutrition in Hematopoietic Stem Cell Transplantation: Graft- versus -host disease was approved by Sociedade Brasileira de Transplante de Medula Óssea , with the participation of 26 Brazilian hematopoietic stem cell transplantation centers. It describes the main nutritional protocols in cases of Graft- versus -host disease, the main complication of hematopoietic stem cell transplantation.

Monocyte-predominant engraftment, cytokine levels and early transplant-related complications in pediatric hematopoietic stem cell recipients

Myeloablative conditioning is a well‐established procedure that precedes hematopoietic stem cell transplantation (HSCT), particularly in pediatric patients. In the period directly following transplantation, several factors may contribute to complications that lead to the activation or damage of endothelial cells, involved in the pathogenesis of vascular endothelial syndromes (VES). However, to date, sufficiently specific and sensitive diagnostic markers for the various forms of VES have not been identified. This was a retrospective single‐center study of patients who underwent allogeneic HSCT. For this cohort of patients, parameters including type of engraftment, donor characteristics, and cytokine production were measured and correlated with a high prevalence of short‐term complications after HSCT. The aim of this study was to identify specific parameters useful for improving diagnostics and predicting adverse effects in VES. We confirmed that monocyte‐predominant engraftment was related to a higher risk for an early transplant‐related complication termed sinusoidal obstruction syndrome (SOS). The increased production of specific cytokines, in particular RANTES, represents a marker associated with prevalent engraftment. In addition, patients undergoing prophylaxis with defibrotide had “classical” engraftment, a common cytokine profile and a lower incidence of life‐threatening transplant‐related complications. The beneficial effect of defibrotide might be a starting point for developing selective prophylaxis for patients with monocyte engraftment to prevent severe early transplant‐related complications.

The onset of vascular endothelial syndromes after hematopoietic stem cell transplantation is significantly associated with monocyte‐predominant engraftment (P < 0.0001). The increased production of specific cytokines, in particular RANTES, represents a marker associated with monocyte‐predominant engraftment. There is close association between the prophylactic administration of defibrotide, a powerful endothelial protector, and the incidence of vascular endothelial syndromes (P < 0.0001). Given the high cost of defibrotide, selective prophylaxis may be considered for patients with extremely high values of RANTES or with monocyte engraftment.

Drug safety evaluation of defibrotide

INTRODUCTION

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of chemotherapeutic conditioning used in preparation for hematopoietic stem-cell transplantation (SCT). Defibrotide (DF) has been shown in Phase II and III trials to improve complete response in patients with severe VOD (sVOD). None of the articles, to date, provide a comprehensive review of the safety of DF in VOD and/or a range of other conditions.

AREAS COVERED

This article reviews current clinical findings on DF, primarily in terms of safety for use in treatment and prophylaxis of VOD, and relevant safety data for its use in other diseases. The literature review was conducted using a PubMed search with the fixed term 'defibrotide' in combination with ≥ 1 of 'safety', 'veno-occlusive disease' (with and without 'treatment', 'prevention'), 'oncology', 'myeloma', 'microangiopathy', 'anti-thrombotic' and 'peripheral vascular disorder'. Related articles from the EBMT and ASH conference websites were also included.

EXPERT OPINION

DF was well tolerated in majority of the studies. The safety profile of DF is largely favourable with toxicities comparable to control populations in the setting of SCT complicated by sVOD.

Protective effects of polydeoxyribonucleotides on cartilage degradation in experimental cultures

The capacity of cartilage self-regeneration is considered to be limited. Joint injuries often evolve in the development of chronic wounds on the cartilage surface. Such lesions are associated with articular cartilage degeneration and osteoarthritis. Re-establishing a correct micro/macro-environment into damaged joints could stop or prevent the degenerative processes. This study investigated the effect of polydeoxyribonucleotides (PDRNs) on cartilage degradation in vitro and on cartilage extracted cells. The activities of matrix metalloproteinases 2 and 9 were measured in PDRN-treated cells and in controls at days 0 and 30 of culture. Human nasal cartilage explants were cultured, and the degree of proteoglycan degradation was assessed by measuring the amount of glycosaminoglycans released into the culture medium. The PDRN properties compared with controls were tested on cartilage tissues to evaluate deposition of extracellular matrix. Chondrocytes treated with PDRNs showed a physiological deposition of extracellular matrix (aggrecan and type II collagen: Western blot, IFA, fluorescence activated cell sorting, Alcian blue and safranin O staining). PDRNs were able to inhibit proteoglycan degradation in cartilage explants. The activities of matrix metalloproteinases 2 and 9 were reduced in all PDRN-treated samples. Our results indicate that PDRNs are suitable for a long-term cultivation of in vitro cartilage and have therapeutic effects on chondrocytes by protecting cartilage.

Blood and marrow transplantation and nutritional support

INTRODUCTION

Undernourishment on hospital admission has been considered as risk factor for complications and increased relapse/nonrelapse mortality in hematopoietic stem cell transplantation (HSCT) patients.

MATERIALS AND METHODS

All patients undergoing HSCT are at an increased risk for malnutrition. The changes in these patients affect mainly protein, energy, and micronutrient metabolism. Nutrition support recommendations are now based on the nutritional status of the individual patient, and total parenteral nutrition is no longer indicated for all HSCT patients. As long as it is possible, an oral route should be use in feeding to avoid complications. When total parenteral nutrition (TPN) should be started is one of the most controversial issues. The following indications for TPN are now generally accepted: severe malnutrition at admission (BMI < 18.5) or weight loss > 10% during treatment or impossibility of oral feeding or failing to meet 60-70% of the requirements over 3 days. Specialized nutritional support containing glutamine or immunomodulatory formulas such as arginine, ω3 polyunsaturated fatty acids, purine/pyrimidines (RNA) may be useful.

RESULT

The complications of TPN are divided into metabolic and those related to central venous catheter. TPN should be progressively decreased while increasing feedings by the oral route. When the patients can cover ≥50% of the daily energy requirements orally (for greater than 5 days), withdrawal of TPN may be appropriate. In patients who have suffered from graft-versus-host disease (GvHD) with intestinal involvement, TPN should be used until the stool volume decreases to <500 ml/day for at least 2 days.

CONCLUSION

Parenteral nutrition allows better modulation of fluid, electrolytes, and nutrient administration which can be of critical importance when complications such as GvHD or VOD arise.

Management of chemotherapy-associated hepatotoxicity in colorectal liver metastases

Effective systemic drugs are increasingly used to treat patients with colorectal liver metastases. Recent trials have shown that chemotherapy can reduce the size of metastases that are unresectable rendering them resectable, and decrease postoperative recurrence rates in patients with initially resectable tumours. The increasing use of chemotherapy for colorectal liver metastases has raised awareness of the potential hepatotoxicities induced by systemic drugs and the effects of these drugs on outcome after hepatic resection. In this Review, we outline the rationale for the use of perioperative chemotherapy for colorectal liver metastases, associations between specific agents and patterns of liver injury, and strategies to treat patients with suspected or known chemotherapy-associated hepatotoxicity.

Angiogenesis alteration by defibrotide: implications for its mechanism of action in severe hepatic veno-occlusive disease

Defibrotide (DF) is a mixture of porcine-derived single-stranded phosphodiester oligonucleotides (9-80-mer; average, 50-mer) that has been successfully used to treat severe hepatic veno-occlusive disease (sVOD) with multiorgan failure (MOF) in patients who have received cytotoxic chemotherapy in preparation for bone marrow transplantation. However, its mechanism of action is unknown. Herein, we show that DF and phosphodiester oligonucleotides can bind to heparin-binding proteins (eg, basic fibroblast growth factor [bFGF] but not vascular endothelial growth factor [VEGF] 165) with low nanomolar affinity. This binding occurred in a length- and concentration-dependent manner. DF can mobilize proangiogenic factors such as bFGF from their depot or storage sites on bovine corneal endothelial matrix. However, these molecules do not interfere with high-affinity binding of bFGF to FGFR1 IIIc but can replace heparin as a required cofactor for binding and hence cellular mitogenesis. DF also protects bFGF against digestion by trypsin and chymotrypsin and from air oxidation. In addition, DF binds to collagen I with low nanomolar affinity and can promote human microvascular endothelial cell-1 (HMEC-1) cell mitogenesis and tubular morphogenesis in three-dimensional collagen I gels. Thus, our data suggest that DF may provide a stimulus to the sinusoidal endothelium of a liver that has suffered a severe angiotoxic event, thus helping to ameliorate the clinical sVOD/MOF syndrome.

Cancer chemotherapy II: atypical hepatic injuries

Although chemotherapy generally is accompanied by regular testing for liver enzyme abnormalities, atypical reactions may occur that escape ordinary detection, because hepatocyte injury is not the primary event. The presence of fatty liver, mitochondrial changes, and even biliary abnormalities can be associated with normal or nearly normal liver enzyme levels. This article discusses unique aspects of liver damage associated with cancer chemotherapy. These unique reactions merit special attention and a special vigilance from clinicians.

Hepatic complications of hematopoietic cell transplantation

Acute and chronic liver disease contributes significantly to morbidity and mortality following hematopoietic cell transplantation (HCT). The best prognostic indicator for the development of severe liver dysfunction is an early rise in liver function test results after HCT. The leading causes soon after HCT are acute graft-versus-host disease (GVHD), sinusoidal obstruction syndrome, drug and total parenteral nutrition hepatotoxicity, sepsis, and viral infection. Hepatic herpesvirus and fungal infections after HCT, though uncommon, can be life-threatening and warrant immediate diagnosis and treatment. Hepatitis B, hepatitis C virus, iron overload, and chronic GVHD are among the most common causes for chronic liver disease after HCT. Because treatments are directed at the underlying etiology of liver disease, prompt diagnosis by means of laboratory tests, hepatic imaging, and often liver biopsy is required after HCT.

Defibrotide, a polydisperse mixture of single-stranded phosphodiester oligonucleotides with lifesaving activity in severe hepatic veno-occlusive disease: clinical outcomes and potential mechanisms of action

Veno-occlusive disease of the liver (VOD) remains a troubling and potentially fatal complication of high-dose chemotherapy and hematopoietic stem cell transplantation conditioning regimens. No effective therapy has been available for these patients to date, and the best supportive care measures remain woefully inadequate. Defibrotide (DF) (Gentium, S.p.A., Como, Italy), a polydisperse mixture of all the single-stranded phosphodiester oligodeoxyribonucleotides that can be obtained from the controlled depolymerization of porcine intestinal mucosal genomic DNA, seems to offer a safe and effective treatment for some patients suffering from severe VOD, a condition for which no accepted standard therapy currently exists. Early clinical studies evaluating the efficacy of DF for the treatment of severe VOD in patients undergoing hematopoietic stem cell transplantation have been very encouraging. Approximately 45% of the patients treated in multiple initial phase II clinical trials achieved a complete response at day +100, demonstrating normalization of serum bilirubin and resolution of the clinical syndrome. However, although multi-institutional, these represented single arm studies. A large, FDA-approved, pivotal, prospective, multi-institutional, global phase III trial of DF vs. historical controls (best available therapy) commenced in the first quarter of 2006 and should provide further validation of DF's efficacy. The drug seems to have few significant side effects, and almost all test subjects who have received this treatment have tolerated it well. Although the mechanism of action remains unclear, the drug exerts minimal systemic anticoagulant effects yet appears to induce numerous antithrombotic and profibrinolytic effects both in vitro and in vivo. It may function as an adenosine receptor agonist and causes increased concentrations of endogenous prostaglandins, which modulate thrombomodulin, platelets, and fibrinolysis. It also appears to block lipopolysaccharide (LPS)-induced tissue factor (TF) expression. However, despite the fact the DF is composed of oligonucleotides, its mechanism of action, which at the present time is unclear, is not related to Watson-Crick base pair-dependent downregulation of gene expression but is rather likely a result of its polyanionic nature.

Chemotherapy-related secondary acute myeloid leukemia in patients diagnosed with osteosarcoma

Secondary acute leukemia (SAL) after treatment of osteosarcoma has been seldom reported in children. Two main mechanisms that can induce SAL have been described. The authors describe two patients who developed SAL after treatment with multiagent therapy. The first patient developed a secondary acute leukemia after treatment with alkylating agents and platinum compounds. The second patient had the clinical and molecular features of a secondary acute leukemia due to topoisomerase II inhibitors. The authors also discuss the data regarding cisplatin-associated SAL. Different molecular and pathogenic agents may be implicated in the development of second malignant neoplasms in long-term survivors of osteosarcomas.

Early graft failure due to a veno-occlusive disease after a pediatric living donor liver transplantation

A 10-month-old boy with biliary atresia after Kasai procedure underwent a living donor liver transplantation (LDLT). Five days after the LDLT, high fever and increased ascites followed by poor bile drainage was accompanied by elevation of serum liver enzymes. Liver biopsy showed occlusion of the central veins by fibro-edematous endothelium and submassive necrosis of the parenchyma. Veno-occlusive disease (VOD) was suspected, and re-LDLT was urgently performed because of deterioration of hepatic failure. There are few cases of VOD after liver transplantation and this is the first one in an infant after LDLT.

Anti-thrombin III in the management of hematopoietic stem-cell transplantation-associated toxicity

OBJECTIVE

To describe the evidence assessing the use of anti-thrombin III (AT-III) in the management of toxicity associated with hematopoietic stem-cell transplantation (HSCT)-conditioning regimens.

DATA SOURCES

Clinical literature was accessed through conference proceedings, EMBASE, the Cochrane database, and MEDLINE (1966-December 2003).

STUDY SELECTION AND DATA EXTRACTION

Case reports, small case series, case-control and cohort studies, and randomized controlled trials of AT-III in HSCT were evaluated. Publications examining AT-III use in the non-HSCT setting were also explored. Key search terms included AT-III, transplantation, and veno-occlusive disease (VOD).

DATA SYNTHESIS

Severe VOD and ensuing multiple organ dysfunction is associated with high mortality in HSCT. A low AT-III level has been shown to correlate with the development of organ dysfunction. Phase II trials, case series, and one small, randomized, placebo-controlled study suggest a benefit when AT-III therapy is instituted early in the course of VOD/multiple organ dysfunction syndrome. In all of these reports, AT-III use was devoid of adverse events.

CONCLUSIONS

Although further studies are needed to ascertain the optimal target level, method, and duration of administration, AT-III is still a viable alternative for the treatment of severe VOD and ensuing multiple organ dysfunction.

Hepatic venoocclusive disease in blood and bone marrow transplantation in children and young adults: incidence, risk factors, and outcome in a cohort of 241 patients

PURPOSE

To describe recent characteristics of incidence, risk factors, treatment, and outcome of venoocclusive disease (VOD) in children and young adults undergoing blood and bone marrow transplantation (BMT).

METHODS

All children and young adults (n = 241) undergoing first myeloablative transplant at the UCSF Pediatric BMT unit between 1992 and 2000 were included. Retrospective chart review was done. Descriptive statistics and univariate and multivariate analyses of risk factors are presented.

RESULTS

Venoocclusive disease developed in 65 patients (27%); it was severe in 13/65 patients (20%). Matched unrelated donor transplantation, advanced-stage malignancies, and transplantation in the recent period (1998-2000) were identified as significant risk factors for VOD in univariate and multivariate analyses. Heparin prophylaxis did not decrease the incidence of VOD. Venoocclusive disease was diagnosed at a median day 8 after BMT. Five of 13 patients with severe VOD (38%) survived for more than 1 year after BMT, even after renal and respiratory failure and high total bilirubin levels up to 35 mg/dL. Nine of the 13 patients received fibrinolytic treatment with tissue plasminogen activator, anti-thrombin 3, or defibrotide. The survival rate at day 100 after BMT for children with VOD was 77%; it was 94% for those without VOD.

CONCLUSIONS

The persistently high incidence of VOD, its significant impact on posttransplant survival, and the demonstration of recovery from even severe VOD underscore the importance of early diagnosis and initiation of specific therapy. The use of Bearman's model of prediction of severity of VOD and the application of fibrinolytic drugs when adequate are highly recommended.

Veno-occlusive Disease

Therapy for veno-occlusive disease of the liver (VOD) occurring after bone marrow transplantation should be directed at those with moderate or severe disease who will not recover on their own. Thrombolytic therapy may have a role in severe VOD as long as there is no renal or lung impairment. However, the risk of bleeding complications, including the risk of cerebral hemorrhage, must be considered in these patients. Defibrotide has shown promise for treatment of severe VOD but is not yet widely available in the United States. Therapy directed at reducing portal hypertension such as transjugular intrahepatic portosystemic shunts helps reduce ascites but has no effect on mortality. Liver transplantation has been reported but should be considered only in patients with severe liver failure who would have a good outcome in the absence of liver disease or have undergone bone marrow transplantation for benign disease. The most important advances in VOD has been in the prevention of this syndrome by recognizing the risk factors for it and changes in conditioning regimens before bone marrow transplantation.

Fludarabine induces apoptosis, activation, and allogenicity in human endothelial and epithelial cells: protective effect of defibrotide

Fludarabine is a nonmyeloablative immunosuppressant increasingly used as a component of alternative conditioning regimens before allogeneic bone marrow transplantation. It is expected to reduce conditioning-related toxicity and proinflammatory activation of the host tissues. However, in our in vitro study, we provide evidence that 2-fluoroadenine 9-beta-D-arabinofuranoside (F-Ara) as the active metabolized form of fludarabine damages human microvascular endothelial cells (HMECs) and dermal and alveolar epithelial cell lines after 48 hours of culture when it is used in pharmacologically relevant concentrations (range, 10 microg/mL-1 microg/mL). In addition, flow cytometric analyses revealed a significant up-regulation of intercellular adhesion molecule 1 and major histocompatibility complex (MHC) class I molecules by F-Ara, suggesting a proinflammatory activation of HMECs. Cytotoxicity assays demonstrated that target HMECs pretreated with F-Ara (10 microg/mL) showed increased lysis by allogeneic MHC class I-restricted cytotoxic T lymphocytes from healthy human donors. We conclude that, beside its immunosuppressive activities, F-Ara can be harmful for target tissues of transplantation-related complications and can even stimulate allogeneic immune responses. We identified the pharmaceutical compound defibrotide as protective against F-Ara- induced apoptosis and alloactivation, importantly, without affecting the antileukemic effect of F-Ara. This observation argues for a potential clinical usage of defibrotide in pretransplantation conditioning.

Liver cirrhosis after prolonged therapy with IFN-alpha plus interleukin-2 in a metastatic renal cancer long-term survivor

Interleukin-2 (IL-2) therapy is associated with serious toxic effects on the cardiopulmonary system. Less frequent toxicity is described in liver and the gastrointestinal system. A case of severe liver toxicity is described in a patient who underwent long-term immunotherapy with IL-2 (4.5 MU/m(2) s.c. daily, 5 days per week for 6 weeks, with 4 weeks of interval) plus interferon-alpha (IFN-alpha) (3 MU s.c. t.i.w., also covering the intervals between IL-2 cycles) for a metastatic renal carcinoma. A review of the literature is provided. The patient tolerated well the immunotherapy scheduled with apparently only a World Health Organization (WHO) G3 anemia and a G2 asthenia and is still alive, with a disease-free survival of 28 months. Notwithstanding a complete absence of liver function test abnormality during all scheduled clinical controls, the patient developed portal hypertension due to liver cirrhosis, which was histologically demonstrated. All common etiologic viral and toxic agents were ruled out. Long-term IL-2 therapy can induce liver cirrhosis. The appearance of liver and spleen enlargement during IL-2 therapy can be considered an indicator of liver damage. Thus, in this setting, closer monitoring is warranted despite normal liver function tests.