Necuparanib, A Multitargeting Heparan Sulfate Mimetic, Targets Tumor and Stromal Compartments in Pancreatic Cancer

Pancreatic cancer has an abysmal 5-year survival rate of 8%, making it a deadly disease with a need for novel therapies. Here we describe a multitargeting heparin-based mimetic, necuparanib, and its antitumor activity in both in vitro and in vivo models of pancreatic cancer. Necuparanib reduced tumor cell proliferation and invasion in a three-dimensional (3D) culture model; in vivo, it extended survival and reduced metastasis. Furthermore, proteomic analysis demonstrated that necuparanib altered the expression levels of multiple proteins involved in cancer-driving pathways including organ development, angiogenesis, proliferation, genomic stability, cellular energetics, and invasion and metastasis. One protein family known to be involved in invasion and metastasis and altered by necuparanib treatment was the matrix metalloprotease (MMP) family. Necuparanib reduced metalloproteinase 1 (MMP1) and increased tissue inhibitor of metalloproteinase 3 (TIMP3) protein levels and was found to increase RNA expression of TIMP3. MMP enzymatic activity was also found to be reduced in the 3D model. Finally, we confirmed necuparanib's in vivo activity by analyzing plasma samples of patients enrolled in a phase I/II study in patients with metastatic pancreatic cancer; treatment with necuparanib plus standard of care significantly increased TIMP3 plasma protein levels. Together, these results demonstrate necuparanib acts as a broad multitargeting therapeutic with in vitro and in vivo anti-invasive and antimetastatic activity.

The Potential Role of Topically Applied Heparan Sulfate in the Treatment of Photodamage

Heparan sulfate is an essential glycosaminoglycan that plays important roles in development, homeostasis, and disease. As a group, the glycosaminoglycans provide mechanical strength to skin, as they can absorb water and occupy the space between elastin fibers and collagen. Heparan sulfate is also a key participant in cell proliferation, cell migration, collagen fiber formation, basement membrane regeneration, granulation tissue formation, and cell adhesion associated with wound healing. A variety of dermatological disorders are associated with changes in glycosaminoglycans or their associated proteoglycans. A new topical formulation of low molecular weight heparan sulfate glycosaminoglycan has been shown to penetrate the epidermis, basement membrane, and dermis within 24 hours of application. In an 8-week study, 15 patients using this new formulation showed improvement in skin hydration, skin firmness, skin elasticity, skin barrier function, and global fine lines and wrinkles. Incorporating low molecular weight heparan sulfate into topically applied formulations may represent a new approach to improving the appearance of photodamaged skin.

High prevalence of femoral head necrosis in Mucopolysaccharidosis type III (Sanfilippo disease): a national, observational, cross-sectional study

BACKGROUND

Sanfilippo disease, or Mucopolysaccharidosis type III (MPS III), is a lysosomal storage disorder and a member of the mucopolysaccharidoses (MPSs). MPS III is clinically characterized by progressive neurodegeneration. Skeletal disease is not felt to be an important clinical component in MPS III patients, unlike in the other MPSs. We conducted radiographic studies in a relatively large group of MPS III patients and detected a high prevalence of osteonecrosis of the femoral head (ONFH).

METHODS

Thirty-three patients were included in the study. All the patients underwent an X-ray of the pelvis (anteroposterior view). All the X-rays were evaluated by a single, blinded radiologist using a modified Ficat classification system for ONFH (the stages ranged from 0 to IV, with increasing stages signifying more severe abnormalities). Clinical symptoms possibly related to hip disease were recorded. The patients were divided into different phenotypes based on mutational analysis and their plasma heparan sulfate (HS) levels.

RESULTS

In 21 of the 33 patients, the disease severity could be predicted by genotype. In 11 of the 12 remaining patients, the phenotype could be assessed via the plasma HS levels. Eight patients (24%) exhibited signs of ONFH (Ficat stage≥I), and 6 (75%) of them had bilateral changes. None of the patients with attenuated MPS III (n=14) had ONFH. In 6 of the patients with a severe phenotype, hip dysplasia was detected as an additional finding. The 7 patients with Ficat stages ≥ II reported hip pain.

CONCLUSIONS

Femoral head disease, which resembles ONFH, is common in patients with the severe MPS III phenotype. An evaluation of hip disease should be included in follow-up visits with MPS III patients.

Parenteral anticoagulants: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

This article describes the pharmacology of approved parenteral anticoagulants. These include the indirect anticoagulants, unfractionated heparin (UFH), low-molecular-weight heparins (LMWHs), fondaparinux, and danaparoid, as well as the direct thrombin inhibitors hirudin, bivalirudin, and argatroban. UFH is a heterogeneous mixture of glycosaminoglycans that bind to antithrombin via a unique pentasaccharide sequence and catalyze the inactivation of thrombin, factor Xa, and other clotting enzymes. Heparin also binds to cells and plasma proteins other than antithrombin causing unpredictable pharmacokinetic and pharmacodynamic properties and triggering nonhemorrhagic side effects, such as heparin-induced thrombocytopenia (HIT) and osteoporosis. LMWHs have greater inhibitory activity against factor Xa than thrombin and exhibit less binding to cells and plasma proteins than heparin. Consequently, LMWH preparations have more predictable pharmacokinetic and pharmacodynamic properties, have a longer half-life than heparin, and are associated with a lower risk of nonhemorrhagic side effects. LMWHs can be administered once daily or bid by subcutaneous injection, without coagulation monitoring. Based on their greater convenience, LMWHs have replaced UFH for many clinical indications. Fondaparinux, a synthetic pentasaccharide, catalyzes the inhibition of factor Xa, but not thrombin, in an antithrombin-dependent fashion. Fondaparinux binds only to antithrombin. Therefore, fondaparinux-associated HIT or osteoporosis is unlikely to occur. Fondaparinux exhibits complete bioavailability when administered subcutaneously, has a longer half-life than LMWHs, and is given once daily by subcutaneous injection in fixed doses, without coagulation monitoring. Three additional parenteral direct thrombin inhibitors and danaparoid are approved as alternatives to heparin in patients with HIT.

Management of allergy to heparins in postoperative care: subcutaneous allergy and intravenous tolerance

Itching erythematous or eczematous plaques around injection sites are quite frequent side effects of heparin treatment and are clinical symptoms of a delayed-type hypersensitivity to heparins. In most cases, changing the subcutaneous therapy from unfractionated to low molecular weight heparin or treatment with heparinoids does not provide improvement, due to extensive cross-reactivity. Interestingly, it has been demonstrated that patients with delayed-type hypersensitivity to subcutaneously injected heparins tolerate intravenous application of heparin in controlled challenge tests. A patient with known delayed-type hypersensitivity to heparins received the heparinoid, danaparoid, subcutaneously for thrombosis prophylaxis after orthopedic surgery. After the first few injections, eczematous plaques developed; administration of the anticoagulant was continued and gradually resulted in generalized eczema despite treatment with topical and oral glucocorticoids. However, the patient required further anticoagulation. After discontinuation of subcutaneous injections and a switch to intravenous heparin, rapid improvement and clearing of skin lesions occurred. Therefore, in cases of delayed-type hypersensitivity to subcutaneously injected heparins, the switch from subcutaneous to intravenous heparin administration may be justified.

A case of heparin-induced thrombocytopenia with repeated episodes of acute lower extremity arterial thromboembolism during a short time

The patient was a 55-year-old female. On the diagnosis of the right acoustic tumor, a subtotal extirpation was performed. Heparinized solution was administered, and on postoperative day 7, an occlusion of the left common femoral artery was confirmed. A continuous administration of heparin was initiated after a thrombectomy. On the following day, the platelet count decreased. Following confirmation of the recurrence of thromboembolism, we again performed a thrombectomy. Considering the possibility of heparin-induced thrombocytopenia (HIT), we terminated the administration of heparin, and treatment with danaparoid and argatroban was initiated. Two days later, she redeveloped thromboembolism. After the administration of danaparoid was terminated, the platelet count improved.

Structure-activity studies of heparan mimetic polyanions for anti-prion therapies

Polysulfated molecules, as the family of heparan mimetics (HMs) and pentosan polysulfate, are considered among the more promising drugs used in experimental models of prion diseases. Regardless of their therapeutic potential, structure-function studies on these polyanions are still missing. Here, we report the syntheses of a library of HMs of different molecular sizes, containing various sulfation and carboxylation levels, and substituted or not by different hydrophobic cores. The HMs capacities to inhibit the accumulation of PrPres in chronically infected cells (ScGT1-7) and their PrPc binding abilities were examined. Our results showed that an optimal size and sulfation degree are needed for optimum activity, that incorporation of hydrophobic moieties increases compounds efficacy and that the presence of carboxymethyl moieties decreases it. These structural features should be considered on the modelling of polyanionic compounds for optimum anti-prion activities and for advancing in the understanding the mechanisms involved in their biological actions.

Pasteurella multocida Sepsis, Due to a Scratch from a Pet Cat, in a Post-Chemotherapy Neutropenic Patient with Non-Hodgkin Lymphoma

Pasteurella (P) multocida exists in a variety of animals and causes diverse infections in humans due to animal bites and scratches, usually by cats or dogs, and oral and respiratory infection. We report a case of P multocida sepsis due to a scratch from a pet cat, complicated with disseminated intravascular coagulation in a post-chemotherapy neutropenic patient with non-Hodgkin lymphoma. The patient was a febrile 79-year-old woman with disturbed consciousness and subcutaneous abscess in her right hand due to a scratch from a pet cat. She was successfully treated with empirical antibiotic therapy with cefepime and administrations of granulocyte colony-stimulating factor and danaparoid. The minimum inhibitory concentration of cefepime against the isolate from this case was <2mg/L. Although a few days are required before a diagnosis of P multocida infection can be made from a bacteriological study, the infection can be successfully treated against febrile neutropenia with empirical cefepime. In a literature review, 7 cases, including ours, with hematological malignancies complicated with P multocida infection were identified and we summarized the clinical characteristics of these cases. These cases demonstrate the importance of the prevention of close contact between pet animals and immunocompromised hosts such as post-chemotherapy neutropenic patients.

Danaparoid sodium reduces ischemia/reperfusion-induced liver injury in rats by attenuating inflammatory responses

This study was undertaken to examine the mechanism by which danaparoid sodium (DS), a heparinoid that contains mainly heparan sulfate, prevents reperfusion-induced hepatic damage in a rat model of ischemia/reperfusion (I/R)-induced liver injury. Administration of DS significantly reduced liver injury and inhibited the decrease in hepatic tissue blood flow in rats. DS attenuated hepatic I/R-induced increases in hepatic tissue levels of tumor necrosis factor (TNF) and myeloperoxidase (MPO) in vivo. In contrast, neither monocytic TNF production nor neutrophil activation was inhibited by DS in vitro. DS enhanced I/R-induced increases in levels of calcitonin-gene related peptide (CGRP), a neuropeptide released from sensory neurons, and of 6-ketoprostaglandin (PG) F (1a) , a stable metabolite of PGI (2) , in liver tissues. The therapeutic effects of DS were not seen in animals pretreated with capsazepine, an inhibitor of sensory neuron activation. The distribution of heparan sulfate in the perivascular area was significantly increased by DS administration in this rat model. DS significantly increased CGRP release from isolated rat dorsal root ganglion neurons (DRG) in vitro, while DX-9065a, a selective inhibitor of activated factor X, did not. DS enhanced anandamide-induced CGRP release from DRG in vitro. These observations strongly suggested that DS might reduce I/R-induced liver injury in rats by attenuating inflammatory responses. These therapeutic effects of DS might be at least partly explained by its enhancement of sensory neuron activation, leading to the increase the endothelial production of PGI (2) .

Results of a systematic evaluation of treatment outcomes for heparin-induced thrombocytopenia in patients receiving danaparoid, ancrod, and/or coumarin explain the rapid shift in clinical practice during the 1990s

INTRODUCTION

Randomized controlled trials evaluating treatment of acute, transient, but uncommon diseases are difficult to perform. The prothrombotic adverse drug reaction, heparin-induced thrombocytopenia (HIT), is such an example. During the mid-1980s, the defibrinogenating snake venom, ancrod (+/-warfarin, Canada), or coumarin (warfarin, Canada; phenprocoumon, Germany) alone, were often used to treat HIT. During the 1990s, danaparoid+/-coumarin began to replace ancrod (+/-coumarin), or coumarin alone, for treating HIT, despite danaparoid not being approved for treatment of HIT.

METHODS

We performed a retrospective evaluation of treatment outcomes from 1986 to 1999, comparing danaparoid+/-coumarin (n=62) versus ancrod+/-coumarin or coumarin alone (controls, n=56).

RESULTS

The predefined composite endpoint of adjudicated new, progressive, or recurrent thrombosis (including thrombotic death), or limb amputation, at day 7 (maximum, one event per patient) was significantly lower in danaparoid-treated patients, compared with controls: 8/62=12.9% (95% CI, 4.3-21.5) vs. 22/56=39.3% (95% CI, 26.1-52.5); p=0.0014. We also found a lower frequency of the composite endpoint at end of study (day 35) in danaparoid-treated patients: 12/62=19.4% vs. 24/56=42.9% (p=0.0088). Major bleeding (by day 7) occurred in 7/62 (11.3%) and 16/56 (28.6%) of danaparoid-treated and control patients, respectively (p=0.0211).

CONCLUSIONS

The replacement of ancrod+/-coumarin, or coumarin alone, by danaparoid (+/-coumarin) in the mid-1990s for the treatment of HIT was justified by improved efficacy and safety.

Clinical Presentation, Temporal Relationship, and Outcome in Thirty-Three Patients With Type 2 Heparin-Induced Thrombocytopenia After Cardiotomy

BACKGROUND

Type 2 heparin-induced thrombocytopenia is an uncommon but often fatal complication of heparin, frequently difficult to diagnose after cardiac surgery. In this series, we record the clinical presentation, temporal relationship, and treatment outcome of patients diagnosed with heparin-induced thrombocytopenia postoperatively.

METHODS

Thirty-three consecutive patients (1.1%) with a diagnosis of heparin-induced thrombocytopenia established by a greater than 50% drop in platelet count with or without a thrombotic event and a positive platelet factor-4 assay were reviewed. We recorded the clinical presentation, the time to presentation, treatment, and outcome (thrombosis, mortality). Univariate analysis was performed on 13 preoperative, operative, and postoperative variables.

RESULTS

The cohort was at increased mortality risk as a result of age (69.4 years), reduced cardiac function (46.8%), nonbypass operations (57.6%), emergency surgery (21.2%), and implantation of three assist devices. The mean time to suspect heparin-induced thrombocytopenia postoperatively was 5.4 days, with 22 cases (66.6%) occurring within 5 days. All patients had previous (within 3 months) exposure to heparin, and 66.6% had ongoing treatment with heparin before surgery. Overall mortality was 33%; thrombotic complications occurred in 15 patients (45.5%), with a mortality of 7 (46.6%) despite immediate cessation of heparin and treatment with a nonheparin analog. Thrombocytopenia without thrombosis occurred in 18 patients (54.5%), but a subgroup of 5 patients with nonthrombotic complications accounted for the 4 (22.2%) deaths.

CONCLUSIONS

Heparin-induced thrombocytopenia after cardiac surgery is uncommon but may occur within 5 days of surgery, further complicating diagnosis and treatment. Thrombotic complications result in a high mortality despite treatment with a nonheparin analog, and a subgroup of patients with thrombocytopenia fared poorly.

Effective targeting of liposomes to liver and hepatocytes in vivo by incorporation of a Plasmodium amino acid sequence

PURPOSE

Several species of the protozoan Plasmodium effectively target mammalian liver during the initial phase of host invasion. The purpose of this study was to demonstrate that a Plasmodium targeting amino acid sequence can be engineered into therapeutic nanoparticle delivery systems.

METHODS

A 19-amino peptide from the circumsporozoite protein of Plasmodium berghei was prepared containing the conserved region I as well as a consensus heparan sulfate proteoglycan binding sequence. This peptide was attached to the distal end of a lipid-polyethylene glycol bioconjugate. The bioconjugate was incorporated into phosphatidylcholine liposomes containing fluorescently labeled lipids to follow blood clearance and organ distribution in vivo.

RESULTS

When administered intravenously into mice, the peptide-containing liposomes were rapidly cleared from the circulation and were recovered almost entirely in the liver. Fluorescence and electron microscopy demonstrated that the liposomes were accumulated both by nonparenchymal cells and hepatocytes, with the majority of the liposomal material associated with hepatocytes. Accumulation of liposomes in the liver was several hundredfold higher compared to heart, lung, and kidney, and more than 10-fold higher compared to spleen. In liver slice experiments, liposome binding was specific to sites sensitive to heparinase.

CONCLUSIONS

Incorporation of amino acid sequences that recognize glycosaminoglycans is an effective strategy for the development of targeted drug delivery systems.

Safety and efficacy of danaparoid (Orgaran) use in children

Immune-mediated heparin-induced thrombocytopenia (HIT) is an uncommon but serious complication of therapy with heparins. It affects all ages and requires replacement of the causative anticoagulant. However, information on alternative antithrombotic use in children with HIT is limited. This paper reviews 27 published and 7 unpublished case reports of children aged 2 weeks to 17 years treated with danaparoid. Thirty-three suffered from HIT or suspected HIT, and 1 child without HIT had a high bleeding risk. All children had severe underlying problems increasing their thrombotic and/or bleeding risk. HIT diagnosis was confirmed serologically or clinically in 26 cases (78.8%). Danaparoid regimens were similar to those used in adults, but in general, younger children needed higher daily doses of danaparoid to achieve the same target plasma anti-Xa levels than teenagers or adults. Of those with a known outcome 28/33 children (84.8%) survived, 7 having suffered from a serious adverse event. Five deaths occurred including 1 thrombotic and 2 major bleeds. Three of the in total 4 major bleeding events occurred in children undergoing surgery with cardiopulmonary bypass. We conclude that despite the reported adverse events danaparoid can be used as an alternative antithrombotic for children who are intolerant of the heparins, except in cases requiring cardiopulmonary bypass surgery.

Treatment of heparin-induced thrombocytopenia in cardiovascular patients

Heparin-induced thrombocytopenia (HIT) is an antibody-mediated syndrome associated with heparin exposure, a falling platelet count and a high risk of thrombosis. Cardiovascular patients are at increased risk of HIT due to wide use of heparin in this population. Should HIT be suspected, heparin must be avoided in most situations, and anticoagulation with an alternative anticoagulant should be instituted. Preferred agents include the direct thrombin inhibitors argatroban and lepirudin, whilst bivalirudin or desirudin (other direct thrombin inhibitors) can be used in some situations. The indirect thrombin inhibitors, danaparoid and fondaparinux, can also be considered at times. These agents and their use in cardiac patients, including patients with acute coronary syndrome, percutaneous coronary interventions, acute ST elevation myocardial infarction or cardiac surgery, will be reviewed.

Effect of combined therapy of danaparoid sodium and tranexamic acid on chronic disseminated intravascular coagulation associated with abdominal aortic aneurysm

Chronic disseminated intravascular coagulation (DIC) is a well-known complication of aortic aneurysm. A 63-year-old man with bleeding tendency and a large palpable abdominal aortic aneurysm (AAA) was diagnosed as having fibrinolysis dominant DIC by the excessive activation of both coagulation and fibrinolysis (plasmin -alpha2 plasmin inhibitor complex concentration is usually >4 microg/ml). Although several treatments were tried, DIC could not be controlled until the patient was given combined therapy of danaparoid (1,250 U/12 h, bolus IV) and tranexamic acid (0.5 g x 3/day, oral administration). This therapy may be beneficial when control for bleeding is required without restricting the ambulatory movement of patients by continuous drip.

Kasabach-Merritt syndrome associated with giant liver hemangioma: the effect of combined therapy with danaparoid sodium and tranexamic acid

n patients with Kasabach-Merritt syndrome (KMS), local activation of coagulation commonly results in disseminated intravascular coagulation (DIC). Progress of DIC is associated with 30-40% mortality as a result of uncontrollable hemorrhage. A 39-year-old woman with an enlarging giant liver hemangioma was diagnosed as having KMS with DIC. To control the hemorrhagic diathesis, we commenced combination therapy for DIC with danaparoid (1,250 Ux2/day, intravenously (IV)) and tranexamic acid (0.5 g x 3/day, peros (PO). Rapid improvement of the bleeding tendency and coagulopathy occurred in response to this treatment - that is, DIC was controlled without removing the giant hemangioma. The therapy did not restrict the behavior of the patient by continuous drip and angiography could be performed without bleeding. Such therapy may be beneficial in chronic DIC with activation of fibrinolysis.

Drug treatment of haemorrhoids

Drug treatment for various anorectal conditions has been known since ancient times. Today, modern as well as traditional drugs are being increasingly used in all grades of symptomatic haemorrhoids. These drugs (oral and local) are used as a part of conservative management or as an adjuvant to invasive outpatient procedures. Flavonoids, in the new formulation of micronised purified flavonoid fraction (MPFF) or as part of the ancient traditional medicine derivative of the Ginkgo tree, are used for relief of acute symptoms (for control of bleeding and re-bleeding in all grades of haemorrhoids). MPFF has been recommended for control of acute bleeding in patients waiting for a definitive outpatient treatment. Similarly, better known drugs such as calcium dobisilate (used in diabetic retinopathy and chronic venous insufficiency), nitrates and nifedipine have also been effective and well tolerated in the medical treatment of haemorrhoids. However, drug treatment is not aimed at curing haemorrhoids. The prime objective of drug therapy is to control the acute phase (bleeding) so that definitive therapy (banding, injection sclerotherapy, infrared photocoagulation, cryotherapy or surgery) can be scheduled at a convenient time.

Cutting edge: an endogenous pathway to systemic inflammatory response syndrome (SIRS)-like reactions through Toll-like receptor 4

Systemic inflammatory response syndrome (SIRS) is typically associated with trauma, surgery, or acute pancreatitis. SIRS resembles sepsis, triggered by exogenous macromolecules such as LPS acting on Toll-like receptors. What triggers SIRS in the absence of infection, however, is unknown. In this study, we report that a SIRS-like response can be induced in mice by administration of soluble heparan sulfate, a glycosaminoglycan associated with nucleated cells and extracellular matrices, and by elastase, which cleaves and releases heparan sulfate proteoglycans. The ability of heparan sulfate and elastase to induce SIRS depends on functional Toll-like receptor 4, because mutant mice lacking that receptor or its function do not respond. These results provide a molecular explanation for the initiation of SIRS.

Heparan sulphate: a putative decondensing agent for human spermatozoa in vivo

BACKGROUND

Human sperm decondense in vitro upon exposure to heparin and glutathione. The aim of this study was to evaluate whether this decondensing ability of heparin in vitro is related to structural characteristics of the molecule and to test the in-vitro decondensing ability of other glycosaminoglycans.

METHODS

Capacitated sperm obtained from normospermic semen samples were decondensed in the presence of heparin (or its equivalent) and glutathione. After fixation with glutaraldehyde, the percentage of decondensed sperm was determined under phase contrast.

RESULTS

The decondensing ability of heparin was related to sulphation characteristics of the molecule: heparin, O-desulphated heparin and N-desulphated-N-acetylated heparin had similar decondensing abilities; N-desulphated was less active and O/N-desulphated-N-acetylated heparin was completely inactive. On the other hand, the decondensing ability of heparin was not affected by molecular weight, within the range 3000-18,000 kDa. When the decondensing ability of different glycosaminoglycans was tested, heparin and heparin sulphate were equally active, while chondroitin sulphate and hyaluronic acid were completely inactive and dermatan sulphate was slightly active.

CONCLUSIONS

Our results indicate that heparin's decondensing ability in vitro is related to sulphation characteristics of the molecule and suggest that heparan sulphate, a structural analogue of heparin, could be a sperm-decondensing agent in vivo.

Danaparoid for heparin-induced thrombocytopenia: an analysis of treatment failures

BACKGROUND

Patients with heparin-induced thrombocytopenia (HIT) (with or without thrombosis) require alternative anticoagulation because of their extreme risk of new thromboembolic complications. The first effective agent for this purpose may be danaparoid, a less-sulfated low molecular weight heparinoid. Recently, direct thrombin inhibitors have been used.

OBJECTIVE

Five HIT patients, who developed new thromboembolic complications while receiving danaparoid, were analyzed to consider possible reasons for treatment failure and to promulgate strategies that improve efficacy.

RESULTS

Three patients had acute HIT, one had recent HIT, and one with remote HIT was re-exposed to heparin during heart surgery. Danaparoid was started as intravenous bolus and infusion in one patient, and as 1250 units subcutaneously twice daily in four patients. The new complications that emerged on danaparoid were new venous thrombi in three patients (one with pulmonary emboli), lower extremity arterial thrombosis in one, myocardial ischemia in one, thromboembolic cardiovascular accidents in one, and fatal bowel necrosis in one (two patients suffered more than one complication). Platelet counts did not improve or worsened in four, improved partially in the other, and parameters of disseminated intravascular coagulation failed to improve in one patient. Four patients responded relatively dramatically when direct thrombin inhibitors were substituted. Possible reasons for danaparoid failure include that: 1) no treatment is expected to completely prevent complications, 2) antithrombin III consumption can blunt efficacy in some patients, 3) low or intermediate doses may be insufficient, and 4) there was clinically significant cross-reactivity of the pathogenic HIT antibodies.

CONCLUSIONS

It is emphasized that the possibility of clinically significant antibody cross-reactivity and that low or intermediate dosage may be inadequate when using danaparoid in therapy of HIT. The latter problem probably extrapolates to other anticoagulants used for HIT.

On the prophylactic and therapeutic use of danaparoid sodium (Orgaran) in patients with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a rare but dangerous complication of heparin prophylaxis or treatment. The present laboratory tests to measure heparin-associated antibodies are not specific. The diagnosis of HIT mainly depends on the decrease in platelet count and on clinical symptoms. To evaluate clinical outcome, bleeding complications and platelet counts were evaluated in 45 patients with HIT type II (HIT II) treated prophylactically (subcutaneous injections) or therapeutically (intravenous infusion) with danaparoid. Group I included 24 patients with HIT II without thromboembolic complications who received danaparoid twice daily subcutaneously (10 IU/kg) for a mean of 16 days. Group II included 21 patients with thromboembolic complications. They were treated with intravenous danaparoid (2.6 IU/kg/h +/- 1.1) for a mean of 17 days. During subcutaneous prophylaxis, mean anti-Xa levels of 0.2 U/mL and during intravenous treatment, mean anti-Xa levels of 0.4 U/mL were reached. No deaths, amputations, or serious bleeding complications occurred, and no new thromboses were observed in both patient groups. Treatment with danaparoid led to a fast normalization of the platelet counts. This normalization occurred earlier and the concentration of platelets was higher in patients treated with intravenous doses. Danaparoid with subsequent vitamin K-antagonist treatment effectively prevents thromboembolic complications in patients with HIT.

Exacerbation of antiphospholipid antibody syndrome after treatment of localized cancer: a report of two cases

Patients with malignancy often present with a variety of coagulation abnormalities which may ultimately lead to recurrent arterial and venous thromboses. Recently the presence of antiphospholipid antibodies in cancer patients has been proposed as one of the potential mechanisms promoting hypercoagulability. Here we report two consecutive patients with localized tumors, one suffering from breast cancer and another presenting with colorectal cancer, who experienced dramatic exacerbation of the antiphospholipid antibody syndrome (APAS) within 4 weeks after surgery. In the first patient who had also received one course of adjuvant chemotherapy, major ischemic stroke and recurrent venous thromboembolism were paralleled by the development of ulcerative livedoid vasculitis and pancytopenia, constituting the diagnosis of systemic lupus erythematosus with secondary APAS. In the second patient, progressive thrombotic occlusion of the superior and inferior vena cava was associated with bilateral pulmonary embolism, acute renal failure, and disabling soft tissue edema. Although not fulfilling the classic criteria of "catastrophic" APAS, the clinical features were life threatening and appeared to be refractory to oral anticoagulation with phenprocoumon. In addition, a diagnosis of Trousseau's syndrome was unlikely due to missing evidence of gross metastatic disease. Besides a suggested treatment strategy comprising high doses of low-molecular-weight heparin, potential pathogenic mechanisms are discussed in consideration of a recently proposed "thrombotic storm," which may cause multiple thromboses after an initial provocation in patients with known hypercoagulability.

[Current recommendations for diagnosis and therapy of heparin-induced thrombocytopenia]

Thrombosis prophylaxis using heparins is mandatory in most trauma patients. However, heparins can induce heparin-induced thrombocytopenia (HIT), the most common and clinically important immune-mediated drug-dependent thrombocytopenia. Affected patients are at risk of developing new thromboembolic complications. HIT has to be considered if platelet counts decrease >50% between day 5-10 of heparin therapy that cannot be explained alternatively or if new thromboses occur in a sufficiently heparinised patient. Immediately changing the anticoagulant to danaparoid or lepirudin is most important. Proof of anti-platelet-factor-4/heparin antibodies secures the diagnosis, usually retrospectively. Diagnosis and therapy are demonstrated in a typical HIT patient. HIT usually occurs in the second week of heparin administration. Heparin-reexposure within 100 days can lead to HIT before day 5. For early recognition of HIT, platelet counts should be monitored regularly. Because of earlier discharge of patients to rehabilitation or outpatient care, the problem of HIT-diagnosis and therapy gains increasing relevance in these sectors.

Lifesaving citrate anticoagulation to bridge ineffective danaparoid [correction of to bridge to danaparoid] treatment

A case of successful regional anticoagulation with trisodium citrate in a patient who developed heparin-induced thrombocytopenia while on continuous hemofiltration is described. Immediate citrate anticoagulation allowed for maintenance of extracorporeal circulation until effective danaparoid therapy could be established. Recommended plasma antifactor Xa levels for hemodialysis may be inadequate in some cases. Values similar to those in use during cardiopulmonary bypass could be required.

Prospective randomised open-label comparison of danaparoid with dextran 70 in the treatment of heparin-induced thrombocytopaenia with thrombosis: a clinical outcome study

AIM

To compare clinical outcomes in a randomised comparison of treatment with danaparoid sodium (a heparinoid), or dextran 70, for heparin-induced thrombocytopaenia (HIT) plus thrombosis.

METHODS

Forty-two patients with recent thrombosis and a clinical diagnosis of probable HIT who presented at ten Australian hospitals during a study period of six and one half years were randomly assigned to open-label treatment with intravenous danaparoid or dextran 70, each combined with oral warfarin. Thirty-four patients (83%) had a positive platelet aggregation or 14C-serotonin release test for HIT antibody. Twenty-five received danaparoid as a bolus injection of 2400 anti-Xa units followed by 400 units per hour for 2 h, 300 units per hour for 2 h, and then 200 units per hour for five days. Seventeen received 1000 mL dextran 70 on day one and then 500 mL on days 2-5. Patients were reviewed daily for clinical evidence of thrombus progression or resolution, fresh thrombosis or embolism, bleeding or other complications. The primary trial endpoint was the proportion of thromboembolic events with complete clinical resolution by the time of discharge from hospital.

RESULTS

With danaparoid, there was complete clinical recovery from 56% of thromboembolic events compared to 14% after dextran 70 (Odds Ratio 10.53, 95% Confidence Interval 1.6-71.4; p = 0.02). Clinical recovery with danaparoid was complete or partial in 86% of thromboembolic events compared with 53% after dextran 70 (Odds Ratio 4.55, 95% Confidence Interval 1.2-16.7; p = 0.03). Overall clinical effectiveness of danaparoid was rated as high or moderate in 88% of patients compared with 47% for dextran 70 (p = 0.01). One patient given danaparoid died of thrombosis compared with three patients given dextran 70. The platelet count returned to normal after a mean of 6.7 days with danaparoid and 7.3 days with dextran 70. There was no major bleeding with either treatment.

CONCLUSION

danaparoid plus warfarin treatment for HIT with thrombosis is effective, safe, and superior to dextran 70 plus warfarin.

Use of a low-molecular-weight heparinoid (danaparoid sodium) for continuous renal replacement therapy in intensive care patients

The purpose of this study was to evaluate the efficacy and safety of danaparoid in the treatment of critically ill patients with acute renal failure and suspected heparin-induced thrombocytopenia (HIT) needing renal replacement therapy (RRT). We conducted a retrospective analysis of 13 consecutive intensive care patients with acute renal failure and suspected HIT who were treated with danaparoid for at least 3 days during RRT. In eight patients, continuous venovenous hemofiltration was performed. The mean infusion rate of danaparoid was 140 +/- 86 U/hour. Filter exchange was necessary every 37.5 hours. In five patients, continuous venovenous hemodialysis was used. A bolus injection of 750 U danaparoid was followed by a mean infusion rate of 138 +/- 122 U/hour. Filters were exchanged every 24 hours. In 7 of 13 patients, even a low mean infusion rate of 88 +/- 35 U/hour was efficient. Mean anti-Xa (aXa) levels were approximately 0.4 +/- 0.2 aXa U/mL. Persistent thrombocytopenia despite discontinuation of heparin treatment was observed in 9 of 13 patients, owing to disseminated intravascular coagulation (DIC). HIT was confirmed by an increase in platelet count and positive heparin-induced antibodies in 2 of 13 patients. No thromboembolic complications occurred, but major bleeding was observed in 6 of 13 patients, which could be explained by consumption of coagulation factors and platelets due to DIC in 5 of 6 patients. Nine of 13 patients died of multiorgan failure or sepsis, or both. In none of these patients was the fatal outcome related to danaparoid treatment. In critically ill patients with renal impairment and suspected HIT, a bolus injection of 750 U danaparoid followed by a mean infusion rate of 50 to 150 U/hour appears to be a safe and efficient treatment option when alternative anticoagulation is necessary.

The effects of danaparoid, dalteparin and heparin on tissue factor-induced experimental disseminated intravascular coagulation and bleeding time in the rat

Danaparoid and heparin, on the basis of anti-activated factor X (anti-FXa) activity, were equipotent in accelerating the rate of interaction of FXa and antithrombin III. In rat tissue factor-induced disseminated intravascular coagulation (DIC) models, an intravenous administration of danaparoid inhibited the decrease in plasma fibrinogen and platelet counts and the increase in serum fibrinogen degradation products. Expressed on the basis of anti-FXa activity, these effects were comparable with those of dalteparin and heparin. In rat mesenteric small artery and vein, less bleeding was observed after intravenous administration of danaparoid than after dalteparin or heparin. Danaparoid did not affect adenosine diphosphate- or collagen-induced platelet aggregation, and showed weaker inhibitory effects on aggregation induced by thrombin, or collagen + thrombin, than did dalteparin or heparin. These findings suggest that danaparoid may be useful for the prevention of DIC and has less tendency to cause bleeding than dalteparin or heparin, probably as a result of its weaker ability to inhibit platelet aggregation.

Danaparoid sodium (Orgaran) in four children with heparin-induced thrombocytopenia type II

We report on four children with heparin-induced thrombocytopenia type II. In three patients, therapy with unfractionated heparin was associated with development of cardiac thrombi or with thrombosis progression up to the inferior vena cava or with aggravation of peripheral arterial occlusion. In the fourth child, the disease was recognized early on, and no complication occurred. Heparin-induced thrombocytopenia type II was confirmed by heparin-induced platelet activation assay and/or heparin/platelet factor 4-ELISA. Concomitant elevated antiphospholipid antibodies were seen in all patients. Danaparoid sodium applied at a dosage of between 1.2 and 7.1 U/kg/h stopped the disease progression in each patient. Three children had a clinical recovery with partial recanalization, but for the child with peripheral arterial occlusion disease, amputation of some of the toes became necessary.

CONCLUSION

Our data indicate that heparin-induced thrombocytopenia type II is a potential life-threatening disease in children and danaparoid sodium is beneficial in this age group.

A comparison of danaparoid and lepirudin in heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a hypercoagulable syndrome strongly associated with thrombosis that is usually treated with drugs that inhibit factor Xa (danaparoid) or thrombin (lepirudin). In the present study the outcome of HIT-patients treated with danaparoid or lepirudin was compared using the single or combined endpoints of new thromboembolic complications (new TECs), amputations and/or death, and major bleeding. HIT-patients treated with lepirudin were enrolled in two prospective trials and patients, who were identified in the same two laboratories during the same time period, who were not enrolled into these studies but treated with danaparoid, were assessed retrospectively according to a standardized questionnaire. 126 danaparoid (60.3% female) and 175 lepirudin treated patients (58.3% female) fulfilled the same inclusion and exclusion criteria. In a time-to-event-analysis the cumulative risk of combined endpoint was higher in HIT-patients without thromboembolic complication at baseline treated with danaparoid (usually in prophylactic dose 750 anti-factor Xa units b.i.d. or t.i.d.s.c.) as compared to lepirudin (aPTT adjusted) (P = 0.020). Whereas HIT-patients with TEC at baseline who were usually treated with therapeutic dose had a similar outcome in both treatment groups (P = 0.913). Major bleeding occurred in 2.5% (95% CI 0.5-7.0%) of danaparoid treated patients as compared to 10.4% (95% CI 6.3-15.9%) of lepirudin treated patients until day 42 (P = 0.009). This indicates that the efficacies of therapeutic doses of danaparoid or lepirudin in preventing death, amputation or new TEC in HIT-patients do not differ largely, but the risk of bleeding seems to be higher in lepirudin treated patients. The prophylactic dose of danaparoid approved in the European Union for HIT without TEC at baseline seems suboptimal. A prospective comparative trial is required to verify these preliminary conclusions.

Novel design of peptides to reverse the anticoagulant activities of heparin and other glycosaminoglycans

Patients undergoing anticoagulation with unfractionated heparin, low molecular weight heparin, or danaparoid may experience excess bleeding which requires reversal of the anticoagulant agent. Protamine is at present the only agent available for reversal of unfractionated heparin. Protamine is not effective in patients who have received low molecular weight heparin or danaparoid. We have developed a series of peptides based on consensus heparin binding sequences (Verrecchio et al., J Biol Chem 2000; 275: 7701-7707) that are capable of neutralizing the anti-thrombin activity of unfractionated heparin in vitro, the antifactor Xa activity of unfractionated heparin, Enoxaparin (Lovenox) and danaparoid (Orgaran) in vitro and the anti-Factor Xa activity of Enoxaparin in vivo in rats. These peptides may serve as alternatives for Protamine reversal of UFH and may be useful for neutralization of enoxaparin and danaparoid in humans.

Management of heparin allergy during pregnancy with danaparoid

We report a patient who presented with a left proximal deep vein thrombosis at 25 + 5 weeks gestation. She developed a severe urticarial rash 3 weeks following initiation of therapy with Enoxaparin. The patient was heterozygous for the factor V Leiden mutation. She was treated with subcutaneous twice-daily danaparoid (Orgaran) for the remainder of the pregnancy, achieving anti-Xa levels in the therapeutic range 0.5-1.0 IU/ml. Delivery was at term by caesarean section 2 days after spontaneous rupture of membranes and failure to progress in labour. Danaparoid was withheld during this time. Danaparoid was restarted 3 h post delivery and the patient anticoagulated with warfarin in the post-partum period. There was no recurrence of thrombosis or bleeding events during therapy with danaparoid. No anti-Xa activity was demonstrated in breast milk.

Cardiac surgery with cardiopulmonary bypass in patients with type II heparin-induced thrombocytopenia

BACKGROUND

The use of cardiopulmonary bypass (CPB) in patients with a history of type II heparin-induced thrombocytopenia (HIT) may be associated with complications related to their anticoagulation management.

METHODS

Between January 1997 and December 1999, among 4,850 adults patients who underwent cardiac surgery in our institution, 10 patients presented with preoperative type II HIT. In 4 patients, anticoagulation during CPB was achieved with danaparoid sodium. In 6 other patients, heparin sodium was used after pretreatment with epoprostenol sodium.

RESULTS

No significant change in platelet count occurred in any patient. No intraoperative thrombotic complication was encountered. Total postoperative chest drainage ranged from 250 to 1,100 ml in patients pretreated with epoprostenol and 1,700 to 2,470 ml in patients who received danaparoid sodium during CPB (p < 0.05, Mann-Whitney U test).

CONCLUSIONS

During CPB, inhibition of platelet aggregation by prostacyclin may be a safe anticoagulation approach in patients with type II HIT.

[Danaparoid (Orgaran) as an antiocoagulant for mechanical autotransfusion with Cell Saver 5 (Hemonetics)]

We investigated Danaparoid Sodium (Orgaran) as anticoagulant using three different concentrations (9, 4,5 or 3 U/ml anticoagulant solution) for the use in the autotransfusion device Cell Saver 5 (Haemonetics). Fresh units of whole blood packs were mixed in the reservoir in a proportion of 5:1 with the anticoagulant solution. Having started the Cell Saver 5 in the automatic mode, the amount of Danaparoid in the retransfusion blood was determined (chromogenic Antifactor-Xa test). The lowest concentration of the anticoagulant was applied in 4 patients with Heparin-induced Thrombocytopenia Type II undergoing total hip arthroplasty. There was a correlation between the concentration in the reservoir and in the retransfusion blood. None of the patients showed a disturbance of his coagulation system. One of them had slight clotting in the reservoir. We recommend the use of the lower concentrations tested: 4,5 U/ml or, particularly for patients with renal insufficiency or low body weight or expected high retransfusion volumes, 3 U/ml as anticoagulant concentrations. If the autotransfusion device is used according to the manufacturer's instructions there may be virtually no risk of clotting in the Cell Saver or of inhibition of the coagulation system in the patient.

Use of danaparoid sodium (Orgaran) as an alternative to heparin sodium during cardiopulmonary bypass: a clinical evaluation of six cases

Heparin-induced thrombocytopenia (HIT) has become more prevalent in today's cardiac setting and has resulted in the need for alternative anticoagulant therapies. Danaparoid sodium, one alternative to heparin, has been used in six cardiopulmonary bypass procedures in this hospital. This clinical experience has resulted in the progressive refinement of a protocol for the 'safe' clinical use of danaparoid sodium. Although there were six positive outcomes with the use of danaparoid sodium, alternatives must be explored in order to find the optimal anticoagulant for the treatment of HIT.

Thromboembolic prophylaxis with danaparoïd (Orgaran) in a high-thrombosis-risk pregnant woman with a history of heparin-induced thrombocytopenia (HIT) and Widal's disease

There is no consensus concerning thromboembolic prophylaxis in high-risk pregnant women with a previous history of heparin-induced thrombocytopenia. An alternative anticoagulant therapy is danaparoïd, whereas unfractioned and low-molecular-weight heparin therapy is contraindicated. We report a case of successful thrombosis prophylaxis using danaparoïd in a high-thrombosis-risk pregnant woman with a history of heparin-induced thrombocytopenia during a previous pregnancy and Widal's disease.

A chronopharmacodynamic study on standard heparin, a low molecular weight heparin (nadroparin) and danaproid: establishing and comparing the daily variations of these drugs in rats

The effects of dosing time on the anticoagulant activity of unfractionated heparin, low molecular weight heparin (nadroparin) and danaproid were investigated. The chronopharmacological comparisons of the drugs were done on the anti-Xa, anti-IIa activities and activated partial thromboplastin time assays. Several dosing times were considered and an analysis based on a population approach was adopted. Under unfractionated heparin, the pharmacological activities did not exhibit significant daily variations. In contrast, significant daily profiles were observed in all the biological assays performed with low molecular weight heparin. Anti-Xa and anti-IIa activities showed some fluctuations over a 24-hour period with a peak at noon. As for the variations of the activated partial thromboplastin time, two peaks were noted early in the morning and at the beginning of nightfall. As for danaproid, only a daytime maximum of anti-Xa activity could be found.

Effects of oral administration of heparan sulphate in the rat remnant kidney model

Heparins are useful for the protection of residual renal function in several nephropathies, but the anticoagulant action and the need of parenteral administration are two main drawbacks limiting their use in chronic renal failure patients. Heparan sulphate (HS) is a heparin-like mucopolysaccharide devoid of anticoagulant action and active orally. In this study, the effects of HS oral administration have been evaluated in 18 subtotally nephrectomized rats;18 untreated remnant kidney rats served as control. No mortality was observed in the HS-treated rats, whereas in the control rats the survival rate was 72.2% at 18 weeks. At the end of the study, HS-treated rats showed lower urinary protein excretion (44 +/- 22 vs. 80 +/- 54 mg/24 h, p < 0.01), lower urea plasma levels (75 +/- 34 vs. 134 +/- 105 mg/dl, p < 0.01) and higher creatinine clearance (66 +/- 15 vs. 47 +/- 21 ml/min. 10(2), p < 0.05) than control rats. Remnant kidney weight (2.3 +/- 1.1 vs. 1.3 +/- 0.2 g, p < 0.01) and heart weight (1.3 +/- 0.2 vs. 1.1 +/- 0.1 g, p < 0.05) were greater in the control than in the HS-treated rats, as well as the systemic blood pressure values (167 +/- 19 vs. 115 +/- 32 mm Hg, respectively, p < 0.001). The remnant kidney histological examination in the HS-treated rats showed a lower prevalence of glomerular sclerosis, mesangial proliferation, and a much less evident tubulointerstitial damage than in controls. The antiproliferative and anti-inflammatory actions of HS together with its protective action on the endothelium are the putative mechanisms that could account for our findings. In conclusion, the present study supports evidence of an antiproteinuric and a renoprotective effect of orally administered HS in subtotally nephrectomized rats. This is in keeping with the well-known effects exerted also by other heparins, but the effectiveness of an orally available heparin-like product in this animal model could suggest the possibility of a clinical use also in progressing chronic renal failure patients.

Danaparoid sodium

Danaparoid sodium (Orgaran, Organon) is a heparinoid glycosamino-glycuronan antithrombotic agent approved for the prophylaxis of post-operative deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE) in patients undergoing elective hip replacement surgery. Danaparoid is a low molecular weight heparinoid consisting of a mixture of heparan sulphate (84%), dermatan sulphate (12%) and small amounts of chondroitin sulphate (4%), whose antithrombotic activity has been well established. Its pharmacological effect is exerted primarily by inhibiting Factors Xa (FXa) and IIa (FIIa) at a ratio greater than heparin, with a minimal effect on platelet function. Danaparoid exhibits low cross-reactivity with heparin-induced antibodies when compared with heparin or low molecular weight heparins (LMWH), thereby making it an excellent choice for the management of heparin-induced thrombocytopenia (HIT). It has excellent bioavailability following s.c. injection. Danaparoid has little effect on routine coagulation tests (activated partial thromboplastin time [aPTT], prothrombin time [PT], and thrombin time [TT]). Patients with elevated serum creatinine should be monitored carefully. For its FDA approved indication (DVT prophylaxis during hip replacement surgery), its cost per day is approximately eight times more than LMWH. Even though monitoring is not routinely necessary according to the manufacturer for its approved indication, monitoring is frequently necessary when it is used in other clinical scenarios. Its higher cost than comparable therapies for DVT prophylaxis and the low availability of the FXa assay in most non-tertiary care hospitals has limited the widespread use of danaparoid. Danaparoid has been found to be effective in the treatment of HIT although this is an off label use, despite being the most frequent reason why danaparoid is used.

Thromboprophylaxis in hip fracture surgery: a pilot study comparing danaparoid, enoxaparin and dalteparin. The TIFDED Study Group

A pilot study was performed to compare the thromboprophylactic effect of danaparoid, enoxaparin and dalteparin in patients with hip fracture. The study was a prospective, randomised assessor-blind, four-centre trial. Prophylaxis was given for 9-11 days, whereafter bilateral phlebography was performed. A total of 197 patients were randomised. There were no statistically significant differences in the frequency of deep vein thrombosis, in blood loss or bleeding complications between the three prophylaxis groups. In conclusion, this moderately sized study revealed no statistically significant difference in efficacy or safety between danaparoid, enoxaparin and dalteparin in patients undergoing hip fracture surgery.