Activated protein C concentrate reverses purpura fulminans in severe genetic protein C deficiency

Skin Necrosis and Purpura Fulminans in Children With and Without Thrombophilia--A Tertiary Center's Experience

Purpura fulminans (PF) is a very rare clinicopathologic skin disorder comprising dermal microvascular thrombosis associated with perivascular hemorrhage of multiple origins. It may occur as the presenting symptom of severe congenital deficiency of protein C (PC) or protein S (PS) during the newborn period, or later in life following oral anticoagulant therapy with vitamin K antagonists, or of sepsis that may be associated with disseminated intravascular coagulation. Treatment consists of anticoagulants and PC concentrates during acute episodes. We report our experience in the diagnosis and management of pediatric PF. The medical records of the 6 children aged 2-16 years (median: 5 years) who presented with PF to our tertiary care center between 1996 and 2013 were studied. The thrombophilia workup revealed either the presence of congenital homozygous PC deficiency, prothrombotic polymorphisms (factor V Leiden and FIIG20210A heterozygosity), acquired PC/PS deficiency, or no discernible thrombophilia. The skin necrosis resolved following conservative fresh-frozen plasma/anticoagulant therapy in 2 cases, whereas 3 children required interventional plastic surgery. The sixth case, a 10-year-old child with severe PC deficiency, heterozygous factor V Leiden, and FIIG20210A, received recombinant activated PC. PF in childhood is rare and has multiple etiologies. Understanding of the variable pathogenesis and risk factors will facilitate diagnosis and appropriate clinical management.

Long-term follow-up of homozygote protein C deficiency after multimodal therapy

Homozygous protein C deficiency is an extremely rare condition presenting in the neonatal period with purpura fulminans, with very high rates of morbidity and mortality. Optimal treatment for this condition is highly complex, poorly understood, and often limited by cost and product supply. We report a child who presented 2 days after birth with purpura fulminans and severe prenatal eye damage, but no cerebral lesions. He was treated with novel multimodal therapy culminating in liver transplant at 3 years of age. The patient is now 12 years of age, well, with blindness as his only long-term deficit.

Pediatric thrombophilia

Pediatric thrombosis and thrombophilia are increasingly recognized and studied. In this article, both the inherited and acquired factors for the development of thrombosis in neonates and children are categorized using the elements of Virchow's triad: stasis, hypercoagulable state, and vascular injury. The indications and rationale for performing thrombophilia testing are described. Also included are discussions on who, how, when, and why to test. Finally, recommendations for the use of contraceptives for adolescent females with a family history of thrombosis are outlined.

Treatment, survival, and thromboembolic outcomes of thrombotic storm in children

OBJECTIVE

To describe the course and management of thrombotic storm in 8 children.

STUDY DESIGN

Clinical data were collected and analyzed for consecutive children diagnosed with thrombotic storm, aged 6 months to 21 years inclusive, in the context of a single-institution prospective inception cohort study. Thrombotic storm was defined as newly diagnosed multisite venous thromboembolism (VTE) with acute thrombus progression despite conventional or higher than conventional dosing of heparin or low molecular weight heparin. All evaluations and therapies were ordered by the treating physicians in the context of clinical decision making.

RESULTS

Eight of the 178 children with VTE enrolled in the cohort between March 2006 and November 2009 were diagnosed with thrombotic storm. Antiphospholipid antibodies were acutely positive in 6 children, of whom heparin-induced thrombocytopenia was confirmed by serotonin release assay in 2 and atypical in 1. One child died. Five children received a direct thrombin inhibitor, titrated to achieve normalization of markedly elevated D-dimer levels. All children were transitioned to fondaparinux or enoxaparin before receiving extended anticoagulation with warfarin. Immunomodulatory therapy was instituted in all children. During follow-up (median duration, 3 years; range, 2-6 years), 3 of the 7 surviving children experienced recurrent VTE, and 4 children had clinically significant postthrombotic syndrome.

CONCLUSION

Thrombotic storm is an infrequent but potentially fatal presentation of VTE in children. Administration of direct thrombin inhibitors and immune modulation can achieve quiescence, although long-term adverse outcomes are common.

Recombinant human activated protein C for severe sepsis in neonates

BACKGROUND

Sepsis is a common problem in preterm and term infants. The incidence of neonatal sepsis has declined, but mortality remains high. Recombinant human activated protein C (rhAPC) possess a broad spectrum of activity modulating coagulation and inflammation. In septic adults it may reduce mortality, but no significant benefit has been reported in children with severe sepsis.

OBJECTIVES

To determine whether treatment with rhAPC reduces mortality and/or morbidity in neonatal sepsis.

SEARCH METHODS

For this update searches were carried out in May 2011 of the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and abstracts of annual meetings of the Pediatric Academic Societies. Doctoral dissertations, theses and the Science Citation Index for articles on activated protein C were searched. No language restriction was applied.

SELECTION CRITERIA

Randomized or quasi-randomized trials, assessing the efficacy of rhAPC compared to placebo or no intervention as an adjunct to antibiotic therapy of suspected or confirmed severe sepsis in term and preterm infants less than 28 days old. Eligible trials should report at least one of the following outcomes: mortality during initial hospital stay, neurodevelopmental assessment at two years of age or later, length of hospital stay, duration of ventilation, chronic lung disease, periventricular leukomalacia, intraventricular haemorrhage, necrotizing enterocolitis, bleeding, and any other adverse events.

DATA COLLECTION AND ANALYSIS

Review authors were to independently evaluate the articles for inclusion criteria and quality, and abstract information for the outcomes of interest. Differences were to be resolved by consensus. The statistical methods were to include relative risk, risk difference, number needed to treat to benefit or number needed to treat to harm for dichotomous and weighed mean difference for continuous outcomes reported with 95% confidence intervals. A fixed effect model was to be used for meta-analysis. Heterogeneity tests, including the I(2) statistic, were to be performed to assess the appropriateness of pooling the data.

MAIN RESULTS

No eligible trials were identified. In October 2011 rhAPC (Xigris®) was withdrawn from the market by Eli Lilly due to a higher mortality in a trial among adults. Xigris® (DrotAA)( rhAPC) should no longer be used in any age category and the product should be returned to the distributor.

AUTHORS' CONCLUSIONS

Despite the scientific rationale for its use, there is insufficient data to use rhAPC for the management of severe sepsis in newborn infants. Due to the results among adults with lack of efficacy, an increase in bleeding and resulting withdrawal of rhAPC from the market, neonates should not be treated with rhAPC and further trials should not be conducted.

Diagnosis and management of neonatal purpura fulminans

Neonatal purpura fulminans is a rare, life-threatening condition, caused by congenital or acquired deficiencies of protein C or S. The condition is often fatal unless there is early recognition of the clinical symptoms, prompt diagnosis, and judicious replacement therapy is initiated. The clinical presentation is that of acute disseminated intravascular coagulation and hemorrhagic skin necrosis. The management includes an acute phase of replacement therapy with fresh frozen plasma or protein C concentrate and a maintenance therapy that includes anticoagulation with warfarin or low molecular weight heparin. This review focuses on the management of severe protein C deficiency.

Severe congenital protein C deficiency: the use of protein C concentrates (human) as replacement therapy for life-threatening blood-clotting complications

The protein C pathway has an important function in regulating and modulating blood coagulation and ensuring patency of the microcirculation. Protein C deficiency leads to macro- and microvascular thrombosis. Congenital severe protein C deficiency is a life-threatening state with neonatal purpura fulminans and pronounced coagulopathy. Patients with heterozygous protein C deficiency have an increased risk for thromboembolic events or experience coumarin-induced skin necrosis during initiation of coumarin therapy. Replacement with protein C concentrates is an established therapy of congenital protein C deficiency, resulting in rapid resolving of coagulopathy and thrombosis without reasonable side effects. This article summarizes the current knowledge on protein C replacement therapy in congenital protein C deficiency.

Empiric treatment of protracted idiopathic purpura fulminans in an infant: a case report and review of the literature

Introduction

Idiopathic purpura fulminans is a cutaneous thrombotic disorder usually caused by autoimmune-mediated protein C or S deficiency. This disorder typically presents with purpura and petechiae that eventually slowly or rapidly coalesce into extensive, necrotic eschars on the extremities. We present the first known case of idiopathic purpura fulminans consistent with prior clinical presentations in the setting of a prothrombotic genetic mutation, but without hallmark biochemical evidence of protein C or protein S deficiency. Another novel feature of our patient's presentation is that discontinuation of anti-coagulation has invariably led to recurrence and formation of new lesions, which is unexpected in idiopathic purpura fulminans because clearance of autoimmune factors should be followed by restoration of anti-coagulant function. Although this disease is rare, infants with suspected idiopathic purpura fulminans should be rapidly diagnosed and immediately anti-coagulated to prevent adverse catastrophic outcomes such as amputation and significant developmental delay.

Case presentation

A six-month-old Caucasian boy was brought to our pediatric hospital service with a low-grade fever and subacute, symmetric, serpiginous, stellate, necrotic eschars on his forearms, legs and feet that eventually spread non-contiguously to his toes, thighs and buttocks. In contrast to his impressive clinical presentation, his serologic evaluation was normal, and he was not responsive to corticosteroids and antibiotics. Full-thickness skin biopsies revealed dermal vessel thrombosis, leading to a diagnosis of idiopathic purpura fulminans and successful treatment with low-molecular-weight heparin, which was transitioned to warfarin. Long-term management has included chronic anti-coagulation because of recurrence of lesions with discontinuation of treatment.

Conclusion

In infants with necrotic eschars, it is important to first consider infectious, inflammatory and hematologic etiologies. In the absence of etiology for protracted idiopathic purpura fulminans, management should include tissue biopsy, in which thrombotic findings warrant a trial of empiric anti-coagulation. Some infants, including our patient, may need long-term anti-coagulation, especially when the underlying etiology of coagulation remains unidentified and symptoms recur when treatment is halted. Given that our patient still requires anti-coagulation, he may have a yet to be identified autoimmune-mediated mechanism for his truly idiopathic case of protracted purpura fulminans.

Long-term subcutaneous protein C replacement in neonatal severe protein C deficiency

We describe here the case of a boy who presented 2 days after birth with purpura fulminans on his feet and scalp. Laboratory investigations revealed signs of disseminated intravascular coagulation. An underlying coagulation disorder was suspected, and therapy with recombinant tissue plasminogen activator, fresh-frozen plasma, and unfractionated heparin was started. On the basis of plasma protein C activity and antigen levels of 0.02 and 0.03 IU/mL, respectively, after administration of fresh-frozen plasma, a diagnosis of severe protein C deficiency was established, and therapy with intravenous protein C concentrate (Ceprotin [Baxter, Deerfield, IL]) was started. Because of difficulties with venous access, we switched to subcutaneous administration after 6 weeks. The precise dosing schedule for subcutaneously administered protein C concentrate is unknown. In the literature, a trough level of protein C activity at >0.25 IU/mL is recommended to prevent recurrent thrombosis. During 1 year of follow-up our patient frequently had protein C activity levels at <0.25 IU/mL. Clinically, however, there was no recurrent thrombosis, and we kept the dosage unchanged. This report highlights 2 important points: (1) subcutaneously administered protein C concentrate is effective in treating severe protein C deficiency; and (2) in accordance with previous studies, after the acute phase trough levels of protein C activity at >0.25 IU/mL may not be necessary to prevent recurrent thrombosis. However, further research on the dosing, efficacy, and safety of protein C concentrate for prophylaxis and treatment of severe protein C deficiency is needed.

Use of human protein C concentrates in the treatment of patients with severe congenital protein C deficiency

Protein C is one of the major inhibitors of the coagulation system that downregulate thrombin generation. Severe congenital protein C deficiency leads to a hypercoagulability state that usually presents at birth with purpura fulminans and/or severe venous and arterial thrombosis. Recurrent thrombotic events are commonly seen. From the 1990’s, several virus-inactivated human protein C concentrates have been developed. These concentrates currently constitute the therapy of choice for the treatment and prevention of clinical manifestations of severe congenital protein C deficiency. This review summarizes the available information on the use of human protein C concentrates in patients with severe congenital protein C deficiency.

Protein C deficiency

Severe protein C deficiency (i.e. protein C activity <1 IU dL(-1)) is a rare autosomal recessive disorder that usually presents in the neonatal period with purpura fulminans (PF) and severe disseminated intravascular coagulation (DIC), often with concomitant venous thromboembolism (VTE). Recurrent thrombotic episodes (PF, DIC, or VTE) are common. Homozygotes and compound heterozygotes often possess a similar phenotype of severe protein C deficiency. Mild (i.e. simple heterozygous) protein C deficiency, by contrast, is often asymptomatic but may involve recurrent VTE episodes, most often triggered by clinical risk factors. The coagulopathy in protein C deficiency is caused by impaired inactivation of factors Va and VIIIa by activated protein C after the propagation phase of coagulation activation. Mutational analysis of symptomatic patients shows a wide range of genetic mutations. Management of acute thrombotic events in severe protein C deficiency typically requires replacement with protein C concentrate while maintaining therapeutic anticoagulation; protein C replacement is also used for prevention of these complications around surgery. Long-term management in severe protein C deficiency involves anticoagulation with or without a protein C replacement regimen. Although many patients with severe protein C deficiency are born with evidence of in utero thrombosis and experience multiple further events, intensive treatment and monitoring can enable these individuals to thrive. Further research is needed to better delineate optimal preventive and therapeutic strategies.

A neonate with homozygous protein C deficiency with a homozygous Arg178Trp mutation

Homozygous protein C deficiency affects approximately 1/400,000 to 1/1,000,000 live births. Homozygous protein C deficiency is associated with catastrophic and fatal purpura fulminans-like or thrombotic complications and disseminated intravascular coagulation. In the present patient, genetic study revealed Arg178Trp, a mutation found widely in European population; but this is the first case of homozygous Arg178Trp mutation who suffered from catastrophic purpura fulminans phenotype.

Recombinant human activated protein C for severe sepsis in neonates

BACKGROUND

Sepsis is a common problem in both preterm and term infants. Although the overall incidence of neonatal sepsis has declined over the past decade, mortality remains high. Recombinant human activated protein C (rhAPC) has been shown to possess a broad spectrum of activity modulating coagulation and has been shown in septic adults to reduce mortality. In septic children, an open label study has shown similar pharmacokinetics, adverse reaction profile and frequency as in adults with severe sepsis.

OBJECTIVES

To determine whether treatment with rhAPC will reduce mortality and/or morbidity in neonates with severe sepsis.

SEARCH STRATEGY

Searches were carried out in July 2005 by the review authors independently of MEDLINE (1966 to July 2005), EMBASE (1980 to July 2005), CINAHL (1982 to July 2005), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2005), abstracts of annual meetings of the Pediatric Academic Societies and Society for Pediatric Research which were published in Pediatric Research from 1980, and contacts were made with subject experts. Doctoral dissertations, theses and the Science Citation Index for articles on activated protein C were searched from 1980. No language restriction was applied.

SELECTION CRITERIA

Studies were included if they were randomized or quasi-randomized trials, assessing the efficacy of rhAPC compared to placebo or no intervention as an adjunct to antibiotic therapy of suspected or confirmed severe sepsis in term and preterm infants less than 28 days old. Eligible trials were required to report treatment effects on at least one of the following outcomes: all cause mortality during initial hospital stay, neurological development and neurodevelopmental assessment at two years of age or later, length of hospital stay, duration of ventilation, chronic lung disease in survivors, periventricular leukomalacia, intraventricular hemorrhage, necrotizing enterocolitis, bleeding, and any other adverse events.

DATA COLLECTION AND ANALYSIS

Both review authors independently evaluated the papers for inclusion criteria and quality, and abstracted information for the outcomes of interest. Differences were resolved by mutual discussion. The statistical methods were to include relative risk, risk difference, number needed to treat to benefit or number needed to treat to harm for dichotomous and weighed mean difference for continuous outcomes reported with 95% confidence intervals. A fixed effects model was to be used for meta-analysis. Heterogeneity tests, including the I(2) statistic, were to be performed to assess the appropriateness of pooling the data.

MAIN RESULTS

No eligible trials were identified.

AUTHORS' CONCLUSIONS

Despite the scientific rationale for its use, there are insufficient data to support the use of rhAPC for the management of severe sepsis in newborn infants. There is a need for large well-designed trials to elucidate the effectiveness of rhAPC to reduce mortality and adverse outcomes in neonates with severe sepsis. The results of such trials would guide clinical practice. Currently, a cautious approach to the use of rhAPC is warranted due to the high incidence of bleeding with its use; especially as severe sepsis in preterm infants is commonly associated with bleeding problems and intraventricular hemorrhage. Its use is not recommended outside of randomized controlled trials.

Issues concerning the laboratory investigation of inherited thrombophilia

Inherited thrombophilia, defined as an increased familial tendency to develop thrombosis, may be due to congenital deficiencies or abnormalities of antithrombin, protein C or protein S; to the presence of a point mutation in the factor V gene (G1691A, factor V Leiden) leading to a poor anticoagulant response to activated protein C; or to the presence of a mutation in the prothrombin gene (G20210A) leading to increased plasma levels of prothrombin. The laboratory investigation of inherited thrombophilia should be limited to patients with a history of venous thromboembolism and, if positive, to their family members even though they are still asymptomatic. There is no indication for indiscriminate screening of the general population or screening of asymptomatic women before prescribing oral contraceptives. Testing should be based on the phenotype for antithrombin, protein C and protein S; on the phenotype and genotype (factor V Leiden mutation) for activated protein C resistance; and on the genotype (G20210A mutation) for hyperprothrombinemia. Phenotypic testing should be performed no sooner than three months after acute thrombotic events and at least 2 weeks after discontinuation of oral anticoagulant treatment.

New anticoagulants: a pediatric perspective

Unfractionated heparin and vitamin K antagonists such as warfarin have been used as the anticoagulants of choice for over five decades. Subsequently, low molecular weight heparins (LMWHs) became widely available and have provided several advantages, especially in infants and children. The field of anticoagulation, however, has undergone a major revolution with better understanding of the structure of coagulation proteins and the development of a host of new drugs with highly specific actions. Many of these drugs have undergone extensive clinical testing in adults and have been approved for specific indications in adults. Unfortunately, clinical data and the reported use of these drugs in children are extremely limited. A lack of familiarity with the actions and pharmacokinetic properties of these drugs could be a major contributing factor. This review focuses on several of the new anticoagulants, with a special emphasis on those that could be potentially beneficial in pediatric patients with thromboembolic disorders. The need for well-designed trials with large-scale participation by pediatric hematologists in order to improve the antithrombotic care of young infants and children is also emphasized.

Calciphylaxis: a rare association with alcoholic cirrhosis. Are deficiencies in protein C and S the cause?

Calciphylaxis is a rare condition of induced systemic hypersensitivity in which tissues respond to appropriate challenging agents with a sudden local calcification. It is characterized by acute calcium deposition in the medial layer of small and intermediate dermal vasculature that can lead to epidermal ischemia, ulceration, and necrosis. Calciphylaxis typically occurs in patients with end-stage renal disease who are undergoing dialysis and who have secondary hyperparathyroidism. Even in this population the incidence is less than 1%. The cause of calciphylaxis is unknown. However, it has been suggested that deficiencies of protein C and protein S may play a role in the pathophysiology of this disorder. Our patient is the fourth with cirrhosis to be reported to have developed calciphylaxis and adds further evidence that low levels of these anticoagulant factors may be an important etiologic factor for development of calciphylaxis. This report should alert the clinician that calciphylaxis occurs in patients with cirrhosis and should stimulate further research concerning the possible role of protein C and protein S deficiency in calciphylaxis.

Drotrecogin alfa (activated) in patients with severe sepsis presenting with purpura fulminans, meningitis, or meningococcal disease: a retrospective analysis of patients enrolled in recent clinical studies

INTRODUCTION

We report data from adult and pediatric patients with severe sepsis from studies evaluating drotrecogin alfa (activated) (DrotAA) and presenting with purpura fulminans (PF), meningitis (MEN), or meningococcal disease (MD) (PF/MEN/MD). Such conditions may be associated with an increased bleeding risk but occur in a relatively small proportion of patients presenting with severe sepsis; pooling data across clinical trials provides an opportunity for improving the characterization of outcomes.

METHODS

A retrospective analysis of placebo-controlled, open-label, and compassionate-use trials was conducted. Adult patients received infusions of either DrotAA or placebo. All pediatric patients (<18 years old) received DrotAA. 189 adult and 121 pediatric patients presented with PF/MEN/MD.

RESULTS

Fewer adult patients with PF/MEN/MD met cardiovascular (68.3% versus 78.8%) or respiratory (57.8% versus 80.5%) organ dysfunction entry criteria than those without. DrotAA-treated adult patients with PF/MEN/MD (n = 163) had an observed 28-day mortality rate of 19.0%, a 28-day serious bleeding event (SBE) rate of 6.1%, and an intracranial hemorrhage (ICH) rate of 4.3%. Six of the seven ICHs occurred in patients with MEN (three of whom were more than 65 years old with a history of hypertension). DrotAA-treated adult patients without PF/MEN/MD (n = 3,088) had an observed 28-day mortality rate of 25.5%, a 28-day SBE rate of 5.8%, and an ICH rate of 1.0%. In contrast, a greater number of pediatric patients with PF/MEN/MD met the cardiovascular organ dysfunction entry criterion (93.5% versus 82.5%) than those without. DrotAA-treated PF/MEN/MD pediatric patients (n = 119) had a 14-day mortality rate of 10.1%, an SBE rate of 5.9%, and an ICH rate of 2.5%. DrotAA-treated pediatric patients without PF/MEN/MD (n = 142) had a 14-day mortality rate of 14.1%, an SBE rate of 9.2%, and an ICH rate of 3.5%.

CONCLUSION

DrotAA-treated adult patients with severe sepsis presenting with PF/MEN/MD had a similar SBE rate, a lower observed 28-day mortality rate, and a higher observed rate of ICH than DrotAA-treated patients without PF/MEN/MD. DrotAA-treated pediatric patients with severe sepsis with PF/MEN/MD may differ from adults, because all three outcome rates (SBE, mortality, and ICH) were lower in pediatric patients with PF/MEN/MD.