Exploration of rotational thromboelastometry (ROTEM) to characterize the coagulation profiles of newly diagnosed pediatric leukemia patients

BACKGROUND

Viscoelastic testing has been used in adult hematologic malignancies in conjunction with conventional coagulation tests (CCTs) to predict coagulopathies and tailor blood product replacement. However, there is a paucity of similar pediatric studies.

OBJECTIVES

Analyze and correlate leukemia-associated coagulopathy in newly diagnosed pediatric leukemia patients using CCT's and Rotational Thromboelastometry (ROTEM).

METHODS

Pediatric patients with newly diagnosed acute leukemia underwent testing with ROTEM and CCTs on days 0, 15 and 29 of induction chemotherapy.

RESULTS

Sixty-two patients were enrolled. At presentation, 54.8 % of patients had platelets <50 K/μL, 73 % had prolonged PT, 1.6 % had fibrinogen <150 mg/dL. Fifteen patients (24.2 %) had WHO grade 1 bleeding and two patients (3 %) had WHO grade 4 bleeding. EXTEM/INTEM values at presentation (day 0) reflected hypocoagulability, however FIBTEM revealed hypercoagulability. Patients showed a progressive hypocoagulability in all ROTEM assays by day 15 (day 0 vs day 15, p < 0.001), with improvement by day 29 (day 15 vs day 29, p < 0.001). Day 0 ROTEM parameters were comparable to day 29. Fibrinogen strongly correlated with ROTEM at all three time points (p < 0.0001), along with platelet count with moderate correlations (p < 0.001).

CONCLUSION

Fibrinogen and platelets appear to be the drivers of leukemia associated coagulopathy in the pediatric population, suggesting the utility of using CCTs and ROTEM in this population to better evaluate hemostatic function and guide blood product replacement.

Prolonged prothrombin time does not correlate with clinical bleeding symptoms in newly diagnosed paediatric leukaemia patients

Prolonged prothrombin time (PT) and/or activated partial thromboplastin time (aPTT) are frequently seen in newly diagnosed paediatric leukaemia patients (NDPLP), which can lead to delayed diagnostic and therapeutic procedures due to concern for bleeding. A single-centre retrospective chart review of NDPLP between 2015 and 2018 aged 1-21 years. We analysed 93 NDPLP of whom 33.3% had bleeding symptoms within 30 days of presentation, predominantly mucosal bleeding (80.6%) and petechiae (64.5%). Median laboratory values: white blood cell count 15.7, haemoglobin 8.1, platelets 64, PT 13.2 and a PTT 31. Red blood cells were administered in 41.2%, platelets in 52.9%, fresh frozen plasma in 7.8% and vitamin K in 21.6% of patients. Prolonged PT was found in 54.8% of patients, while aPTT was prolonged in 5.4%. Anaemia and thrombocytopenia did not correlate with prolonged PT ( P  = 0.73 and P  = 0.18, respectively), or prolonged aPTT ( P  = 0.52 and 0.42). Leukocytosis showed significant correlation with elevated PT ( P  < 0.001), but not aPTT ( P  = 0.3). Bleeding symptoms upon presentation did not correlate with prolonged PT ( P  = 0.83), prolonged aPTT ( P  = 1) or anaemia ( P  = 0.06) but had a significant correlation with thrombocytopenia ( P  ≤ 0.0001). Therefore, a prolonged PT in NDPLP may not necessitate the reflexive use of blood product replacement, in the absence of significant bleeding, which is likely related to leukocytosis than to a true coagulopathy.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities for ultra-rare inherited bleeding disorders

BACKGROUND

Ultra-rare inherited bleeding disorders (BDs) present important challenges for generating a strong evidence foundation for optimal diagnosis and management. Without disorder-appropriate treatment, affected individuals potentially face life-threatening bleeding, delayed diagnosis, suboptimal management of invasive procedures, psychosocial distress, pain, and decreased quality-of-life.

RESEARCH DESIGN AND METHODS

The National Hemophilia Foundation (NHF) and the American Thrombosis and Hemostasis Network identified the priorities of people with inherited BDs and their caregivers, through extensive inclusive community consultations, to inform a blueprint for future decades of research. Multidisciplinary expert Working Group (WG) 3 distilled highly feasible transformative ultra-rare inherited BD research opportunities from the community-identified priorities.

RESULTS

WG3 identified three focus areas with the potential to advance the needs of all people with ultra-rare inherited BDs and scored the feasibility, impact, and risk of priority initiatives, including 13 in systems biology and mechanistic science; 2 in clinical research, data collection, and research infrastructure; and 5 in the regulatory process for novel therapeutics and required data collection.

CONCLUSIONS

Centralization and expansion of expertise and resources, flexible innovative research and regulatory approaches, and inclusion of all people with ultra-rare inherited BDs and their health care professionals will be essential to capitalize on the opportunities outlined herein.

Caregiver Knowledge of and Attitudes Toward the Levonorgestrel-Containing Intrauterine Device for the Treatment of Heavy Menstrual Bleeding in Adolescents and Young Adults

STUDY OBJECTIVE

We evaluated caretaker knowledge of and attitudes toward the levonorgestrel-containing intrauterine device (L-IUD) as a treatment option for adolescents and young adults with heavy menstrual bleeding.

DESIGN

A survey assessed demographic characteristics, menstrual history, perception of the L-IUD, and knowledge of the indications, risks, and benefits of the L-IUD.

SETTING

Participant recruitment occurred in the offices of a pediatric gynecologist, pediatric hematologist, and adolescent medicine physician in a hospital-based practice in New York.

PARTICIPANTS

English-speaking caretakers of patients with a chief concern of heavy menstrual bleeding (<21 years old) were invited to participate.

INTERVENTIONS

Electronic and paper surveys were administered prior to seeing the physician.

MAIN OUTCOME MEASURES

The primary outcome was participant willingness to allow their daughter to use the L-IUD for heavy menstrual bleeding. Additional outcomes were explored by calculating a mean knowledge score and conducting a descriptive analysis of the perception questions.

RESULTS

Forty surveys were included. Seventy percent of participants said they would allow their daughter to use birth control pills for heavy menstrual bleeding, whereas only 10% said the same of the L-IUD. The mean knowledge score was 73.3% (±15.7). Sixty-five percent of participants expressed the need for additional information on the L-IUD.

CONCLUSION

Caretaker acceptance of the L-IUD as treatment for their daughter with heavy menstrual bleeding is limited. Although baseline knowledge was high, many indicated needing additional information. Because heavy menstrual bleeding can negatively impact quality of life, potential caretaker bias must be addressed to ensure full access to this highly effective treatment option.

Primary thromboprophylaxis to prevent thrombotic events in pediatric oncology patients with a malignant mediastinal mass

Children with malignant mediastinal masses have increased thrombotic events (TE). Eligible subjects with malignant mediastinal masses between January 2000 and December 2017 were evaluated for TE, with 19 among 76 subjects receiving enoxaparin thromboprophylaxis. There were 13 TEs among 76 subjects for an incidence of 17.1%. Mediastinal compression directly led to TE in 9.2% of subjects who also had statistically significant superior vena cava compression at diagnosis. Primary thromboprophylaxis did not significantly affect TE occurrence; however, larger studies are warranted to consider strategic thromboprophylaxis guided by radiological monitoring of dynamic vascular compression to improve TE outcomes.

Six Month Follow-up of Patients With Multi-System Inflammatory Syndrome in Children

BACKGROUND AND OBJECTIVES

Myocardial dysfunction and coronary abnormalities are prominent features of multisystem inflammatory syndrome in children (MIS-C). In this study we aim to evaluate the early and midterm outcomes of MIS-C.

METHODS

This is a longitudinal 6-month cohort study of all children admitted and treated for MIS-C from April 17 to June 20, 2020. Patients were followed ∼2 weeks, 8 weeks, and 6 months postadmission, with those with coronary aneurysms evaluated more frequently.

RESULTS

Acutely, 31 (62%) patients required intensive care with vasoactive support, 26 (52%) had left ventricular (LV) systolic dysfunction, 16 (32%) had LV diastolic dysfunction, 8 (16%) had coronary aneurysms (z score ≥2.5), and 4 (8%) had coronary dilation (z score <2.5). A total of 48 patients (96%) received immunomodulatory treatment. At 2 weeks, there was persistent mild LV systolic dysfunction in 1 patient, coronary aneurysms in 2, and dilated coronary artery in 1. By 8 weeks through 6 months, all patients returned to functional baseline with normal LV systolic function and resolution of coronary abnormalities. Cardiac MRI performed during recovery in select patients revealed no myocardial edema or fibrosis. Some patients demonstrated persistent diastolic dysfunction at 2 weeks (5, 11%), 8 weeks (4, 9%), and 6 months (1, 4%).

CONCLUSIONS

Children with MIS-C treated with immunomodulators have favorable early outcomes with no mortality, normalization of LV systolic function, recovery of coronary abnormalities, and no inflammation or scarring on cardiac MRI. Persistence of diastolic dysfunction is of uncertain significance and indicates need for larger studies to improve understanding of MIS-C. These findings may help guide clinical management, outpatient monitoring, and considerations for sports clearance.

Multisystem inflammatory syndrome in children (MIS-C) and the prothrombotic state: Coagulation profiles and rotational thromboelastometry in a MIS-C cohort

BACKGROUND

Adults infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have had high rates of thrombosis. A novel condition in children infected with SARS-CoV-2, multisystem inflammatory syndrome in children (MIS-C), has limited data on their prothrombotic state or need for thromboprophylaxis.

OBJECTIVES

We aimed to analyze the prothrombotic state using coagulation profiles, rotational thromboelastometry (ROTEM) parameters and clinical outcomes, to determine if this could aid in risk stratification for thromboprophylaxis.

METHODS

This analysis included patients (<21 years of age) with a diagnosis of MIS-C (n = 40) and controls (presenting with suspicion of MIS-C but later ruled out; n = 26).

RESULTS

MIS-C patients had higher levels of inflammatory markers including D-dimer (p < .0001), compared with controls, along with evidence of hypercoagulability on ROTEM with elevated evaluation of fibrinogen activity (FIBTEM) maximum clot firmness (MCF) (p < .05). For MIS-C patients with D-dimers >1000 ng/ml, there was a significant correlation of FIBTEM MCF (p < .0001) with a mean value of 37.4 (standard deviation 5.1). D-dimer >2144 ng/ml was predictive of intensive care unit admission (area under the curve [AUC] 0.80; 95% confidence interval, 0.60-0.99; p < .01; sensitivity: 82%, specificity: 75%), and elevated FIBTEM MCF (AUC 1 for >2500 ng/ml). MIS-C patients (50%) received enoxaparin thromboprophylaxis (in addition to aspirin) with significant improvement in their inflammatory and ROTEM parameters upon outpatient follow-up; none developed symptomatic thrombosis.

CONCLUSIONS

Despite an observed prothrombotic state, none of the MIS-C patients (on aspirin alone or in combination with enoxaparin) developed symptomatic thrombosis. ROTEM, in addition to coagulation profiles, may be helpful to tailor thromboprophylaxis in critically ill MIS-C patients.

Are children with SARS-CoV-2 infection at high risk for thrombosis? Viscoelastic testing and coagulation profiles in a case series of pediatric patients

The coagulopathy of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is well documented in adults, with increases in D-dimer and prothrombin time found to be strong predictors of mortality, and anticoagulation shown to decrease this mortality. Viscoelastic parameters such as elevations in maximum clot firmness (MCF) on rotational thromboelastometry (ROTEM) have correlated with a hypercoagulable state in adults with SARS-CoV-2. We report our experience in children infected with SARS-CoV-2, with noted elevations in D-dimer and MCF on ROTEM (indicating hypercoagulability). Exploration of viscoelastic testing to provide additional laboratory-based evidence for pediatric-specific risk assessment for thromboprophylaxis in SARS-CoV-2 is warranted.

Inherited disorders of the fibrinolytic pathway

Deficiencies or excessive activation of the  fibrinolytic system can result in severe, lifelong bleeding disorders. The most severe clinical phenotype is caused by α2-Antiplasmin (α2-AP) deficiency which results in excess fibrinolysis due to the inability to inhibit plasmin. Another bleeding disorder due to a defect in the fibrinolytic pathway results from Plasminogen activator inhibitor-1 (PAI-1) deficiency causing enhanced fibrinolysis due to the decreased inhibition of plasminogen activators resulting in increased conversion of plasminogen to plasmin. Both these disorders are rare and have an autosomal recessive pattern of inheritance. They can remain undetected as routine coagulation and platelet function tests are normal. A unique gain-of-function defect in fibrinolysis causes the Quebec platelet disorder (QPD) which is characterized by profibrinolytic platelets containing increased urokinase-type plasminogen activator (uPA) in the α-granules. A high index of suspicion based on clinical phenotype along with the availability of specialized hemostasis testing is required for timely and accurate diagnosis. Antifibrinolytic agents, such as tranexamic acid or ε-aminocaproic acid, are the mainstays of treatment which inhibit fibrinolysis by preventing the binding of plasminogen to fibrin and thereby stabilizing the fibrin clot. The purpose of this review is to summarize the pathogenesis, clinical phenotype, approaches to diagnosis and treatment for these three major disorders of fibrinolysis.

Management of rare coagulation disorders in 2018

Rare bleeding disorders (RBDs) comprise inherited deficiencies of factors I (fibrinogen), II (prothrombin), V, VII, X, XI, and XIII as well as combined factor V + VIII and vitamin K-dependent factors. They represent 3-5% of all congenital bleeding disorders and are usually transmitted as autosomal recessive traits. These disorders often manifest during childhood and have varied clinical presentations from mucocutaneous bleeding to life-threatening symptoms such as central nervous system and gastrointestinal bleeding. Bleeding manifestations generally vary within the same RBD and may also vary from 1 RBD to the other. Laboratory diagnosis is based on coagulation screening tests and specific factor assays, with molecular techniques providing diagnostic accuracy and enabling prenatal counseling. The approach to treatment of bleeding episodes and invasive procedures needs to be individualized and depends on the severity, frequency and procedure-related risk of bleeding. The first line of treatment of RBDs is replacement of the deficient factor, using specific plasma-derived or recombinant products and using fresh frozen plasma or cryoprecipitate when specific products are not available or in resource-limited countries. Prophylaxis may be considered in individuals with recurrent serious bleeding and especially after life-threatening bleeding episodes. Novel no-replacement strategies promoting hemostasis by through different mechanisms need to be studied in RBDs as alternative therapeutic options.

Point-of-care ultrasonography (POCUS) in hemophilia A: a commentary on current status and its potential role for improving prophylaxis management in severe hemophilia A

In patients with severe hemophilia A, recurrent bleeding into joints results in increased morbidity and reduced quality of life. Prophylaxis using replacement factor products, especially when initiated early, has established benefits in terms of reducing joint bleeds and preserving joint function. Poor adherence to prophylactic regimens is a common cause for breakthrough bleeds and resultant arthropathy. Improving prophylaxis management, especially in the transitional age group, is a challenge. Here, we discuss the current status of ultrasonography (US) in hemophilia A, challenges in its wider implementation, and the potential for use of point-of-care US (POCUS) as an adjunct in the routine management of patients with hemophilia following prophylaxis regimens. Using POCUS, in which US is performed by trained hematologists and nonphysician operators (rather than comprehensive US performed by imaging specialists), specific clinical questions can be addressed in a time-efficient, user-friendly manner to promote adherence to prophylaxis and guide or modify treatment approaches. This review also discusses barriers to acceptance of POCUS as a part of routine management of patients with hemophilia, including questions related to its diagnostic accuracy, dependence on trained operators, agreement on appropriate scoring systems, and potential usefulness in patient management.

Bleeding Disorders in Congenital Syndromes

Pediatricians provide a medical home for children with congenital syndromes who often need complex multidisciplinary care. There are some syndromes associated with thrombocytopenia, inherited platelet disorders, factor deficiencies, connective tissue disorders, and vascular abnormalities, which pose a real risk of bleeding in affected children associated with trauma or surgeries. The risk of bleeding is not often an obvious feature of the syndrome and not well documented in the literature. This makes it especially hard for pediatricians who may care for a handful of children with these rare congenital syndromes in their lifetime. This review provides an overview of the etiology of bleeding in the different congenital syndromes along with a concise review of the hematologic and nonhematologic clinical manifestations. It also highlights the need and timing of diagnostic evaluation to uncover the bleeding risk in these syndromes emphasizing a primary care approach.

Advances in hemophilia and the role of current and emerging prophylaxis

The primary goal of hemophilia treatment and management is the prevention of painful, disabling, and costly joint arthropathy that results from its characteristic bleeding into joints and muscles. Prophylactic treatment with clotting-factor concentrates has been shown to prevent hemophilic arthropathy and is, therefore, the standard of care for hemophilia A and B. Data has demonstrated the clinical efficacy and overall benefits of prophylaxis in young children, adolescents, and adults. Early initiation with prima-ry prophylaxis is ideal, but secondary prophylaxis in adolescents and adults has also demonstrated significant success. Because the standard of care includes prophylaxis with factor-concentrate replacement in order to prevent joint damage in patients with hemophilia, prophylaxis is now more common and needs to be addressed in all clinical settings, including managed care. However, further research is needed to help clinicians develop individualized factor-replacement protocols and under-stand the impact of long-term use into adulthood. World Federation of Hemophilia guidelines do not have definitive recommendations on continuation of prophylaxis into adulthood. The optimal regimen for initiating prophylaxis, duration of treatment, and dosing regimens continue to be studied.

Rare bleeding disorders in children: identification and primary care management

Bleeding symptoms are common in healthy children but occasionally may indicate an underlying congenital or acquired bleeding diathesis. The rare bleeding disorders (RBDs) comprise inherited deficiencies of coagulation factors I (congenital fibrinogen deficiencies), II, V, VII, X, XI, and XIII and combined factor deficiencies, most notably of factors V and VIII and of vitamin K-dependent factors. These disorders often manifest during childhood and may present with recurrent or even serious or life-threatening bleeding episodes, particularly during the neonatal period. Accordingly, primary care and other nonhematologist pediatric providers should be familiar with the clinical presentation and initial evaluation of these rare disorders. Bleeding manifestations generally vary within the same RBD and may be indistinguishable from 1 RBD to another or from other more common bleeding disorders. Serious bleeding events such as intracranial hemorrhage may be heralded by less serious bleeding symptoms. The results of initial coagulation studies, especially prothrombin time and activated partial thromboplastin time, are often helpful in narrowing down the potential factor deficiency, with factor XIII deficiency being an exception. Consultation with a hematologist is advised to facilitate accurate diagnosis and to ensure proper management and follow-up. The approach to bleeding episodes and invasive procedures is individualized and depends on the severity, frequency, and, in the case of procedures, likelihood of bleeding. Prophylaxis may be appropriate in children with recurrent serious bleeding and specifically after life-threatening bleeding episodes. When available, specific purified plasma-derived or recombinant factor concentrates, rather than fresh frozen plasma or cryoprecipitate, are the treatment of choice.

Use of global assays to understand clinical phenotype in congenital factor VII deficiency

Congenital factor VII (FVII) deficiency is characterized by genotypic variability and phenotypic heterogeneity. Traditional screening and factor assays are unable to reliably predict clinical bleeding phenotype and guide haemorrhage prevention strategy. Global assays of coagulation and fibrinolysis may better characterize overall haemostatic balance and aid in haemorrhagic risk assessment. We evaluated the ability of novel global assays to better understand clinical bleeding severity in congenital FVII deficiency. Subjects underwent central determination of factor VII activity (FVII:C) as well as clot formation and lysis (CloFAL) and simultaneous thrombin and plasmin generation (STP) global assay analysis. A bleeding score was assigned to each subject through medical chart review. Global assay parameters were analysed with respect to bleeding score and FVII:C. Subgroup analyses were performed on paediatric subjects and subjects with FVII ≥ 1 IU dL(-1). CloFAL fibrinolytic index (FI2 ) inversely correlated with FVII:C while CloFAL maximum amplitude (MA) and STP maximum velocity of thrombin generation (VT max) varied directly with FVII:C. CloFAL FI2 directly correlated with bleeding score among subjects in both the total cohort and paediatric subcohort, but not among subjects with FVII ≥ 1 IU dL(-1) . Among subjects with FVII ≥ 1 IU dL(-1), STP time to maximum velocity of thrombin generation and time to maximum velocity of plasmin generation inversely correlated with bleeding score. These preliminary findings suggest a novel potential link between a hyperfibrinolytic state in bleeding severity and congenital FVII deficiency, an observation that should be further explored.

Heavy menstrual bleeding in adolescents: hormonal or hematologic?

Adolescence in girls is marked by a host of physical and psychological changes including those associated with menstruation. Heavy menstrual bleeding is one of the most commonly encountered medical problems during transition from childhood to adulthood. Although common, it is likely underreported given that the definition is dependent upon personal experience and influenced by their perception of "normal". Anovulatory cycles related to an immaturity of the hypothalamic pituitary ovarian axis seems to be common, however bleeding disorders such as coagulation factor deficiencies including von Willebrand disease, and quantitative and qualitative abnormalities of platelets must be ruled out. Other medical conditions such as endocrinopathies including diabetes mellitus, Cushing syndrome, polycystic ovarian syndrome, hypothyroidism, chronic hepatic and renal disease, anatomical uterine anomalies, pregnancy, obesity, medications causing hyperprolactinemia must also be considered. Management is based on the presence of hemodynamic instability and acuity of presentation. Treatment options include the use of combined oral contraceptive pills and antifibrinolytic agents; levonorgesterel impregnated intrauterine devices and or treatment of the specific underling bleeding disorder or endocrinopathy. Ongoing management needs to be accomplished through a multi disciplinary team approach in a comprehensive care setting with an adolescent gynecologist, hematologist, pediatrician, and nutritionist involved in the program for a better outcome of this problem.

Rare inherited disorders of fibrinogen

Fibrinogen, a hexameric glycoprotein encoded by three genes - FGA, FGB, FGG - clustered on chromosome 4q is involved in the final steps of coagulation as a precursor of fibrin monomers required for the formation of the haemostatic plug. Inherited disorders of fibrinogen abnormalities are rare and not as well clinically characterized as some other inherited bleeding disorders. To characterize the clinical manifestations, molecular defects and treatment modalities of these rare disorders, a Medline search from January 1966 to September 2007 for these disorders reported in large studies and registries was undertaken. Inherited fibrinogen disorders can manifest as quantitative defects (afibrinogenemia and hypofibrinogenemia) or qualitative defects (dysfibrinogenemia). Quantitative fibrinogen deficiencies may result from mutations affecting fibrinogen synthesis, or processing while qualitative defects are caused by mutations causing abnormal polymerization, defective cross-linking or defective assembly of the fibrinolytic system. Clinical manifestations vary from being asymptomatic to developing catastrophic life-threatening bleeds or thromboembolic events. Management of bleeds includes use of purified plasma-derived concentrates, cryoprecipitate or fresh frozen plasma. Use of some of these products carries risks of viral transmission, antibody development and thromboembolic events. Establishment of registries in Iran, Italy and North America has fostered a better understanding of these disorders with an attempt to explore molecular defects. Rare Bleeding Disorder Registries developed through the United States and international efforts hopefully will encourage development and licensure of safer, effective products.

Power Doppler sonography in the diagnosis of hemophilic synovitis--a promising tool

BACKGROUND

Recurrent hemarthroses in hemophilia results in synovitis and joint arthropathy. Primary prophylaxis when universally instituted at current doses can prevent joint deterioration but is expensive. Alternatively, the selective implementation of prophylaxis would require a more sensitive tool for detecting synovitis than possible with clinical surveillance or plain radiographs. Magnetic resonance imaging (MRI) is such a tool and is utilized for the evaluation of hemophilic joint disease (HJD). However, it is expensive, and requires sedation in younger children precluding its utility for monitoring of synovitis. Ultrasonography (USG) with power Doppler (USG-PDS) has been utilized to detect and quantitate synovial vascularity in other arthritides and could provide an equally effective but less costly tool for HJD, particularly in children who would not require sedation.

OBJECTIVES

To determine whether USG-PDS is comparable to MRI in the evaluation of hemophilic synovitis.

PATIENTS

A prospective cohort of 31 subjects including 33 joints (knees, elbows, ankles) underwent dynamic contrast enhanced (DCE)-MRI and USG-PDS.

RESULTS

USG-PDS measurements of synovial thickness(r = 0.70, P < 0.0001) and synovial vascularity (r = 0.73, P < 0.0001) correlated strongly with those obtained with DCE-MRI. A cutoff of PDS intensity of 1.3 decibels (dB) per mm(2) was found to yield a sensitivity of 100% and a specificity of 94.1% in 17 joints with/without a history of hemarthroses. Pettersson radiographic scores correlated significantly with synovial thickness in adults but not children.

CONCLUSIONS

Our data suggest that USG-PDS may be an inexpensive and easily implemented imaging tool for detecting hemophilic synovitis and could be useful in tailoring effective prophylaxis.

Exemestane: a milestone against breast cancer

Rapid advances in the treatment of breast cancer, especially in the form of hormone therapy have truly increased the hope of longer and better disease-free survival for these patients. Exemestane, a third generation aromatase inhibitor has been extensively evaluated in metastatic as well as adjuvant therapy of breast cancer. It has also been evaluated for its safety profile, especially on bone and lipids. Exemestane provides hope to the patients with breast cancer both in early and metastatic disease. This review analyzes all the aspects of exemestane therapy.

Management of factor VIII inhibitors

The development of inhibitory alloantibodies to factor VIII is arguably one of the most severe and important complications of clotting factor concentrate exposure in haemophilia A. The development of an inhibitor compromises the ability to effectively manage haemorrhage, resulting in a greater rate of disability, complications and costs of therapy. This chapter briefly reviews the epidemiology, immunobiology, and laboratory evaluation of inhibitors. It discusses the therapeutic approach and management of inhibitors in various clinical settings and also focuses on inhibitor eradication practices (immune tolerance) and newer experimental strategies with potential clinical application for inhibitor prevention.

Orthopedic management of hemophilia

Hemophilia is an X-linked inherited bleeding disorder characterized by a deficiency of clotting factor VIII or IX in the intrinsic pathway of the coagulation cascade. This disease can have a profound, debilitating effect on the musculoskeletal system through recurrent hemarthroses and intermuscular hematomas. Although medical management with replacement factor is often effective, patients with severe hemophilia may develop chronic synovitis and arthropathy best treated with more invasive means. Radioactive synovectomy performed at select hemophilia centers and arthroscopic or open synovectomy are helpful for chronic, active synovitis. Arthroplasty helps improve function and pain relief for most patients, but complication rates, particularly for infection, are higher than those for arthroplasty performed on patients without hemophilia.

Rare Bleeding Disorder Registry: deficiencies of factors II, V, VII, X, XIII, fibrinogen and dysfibrinogenemias

A North American registry for rare bleeding disorders [factor (F)II, factor (F)VII, factor (F)X, factor (F)V, factor (F)XIII, fibrinogen deficiencies and dysfibrinogenemias] was established to gather information about disease prevalence, genotyping frequency, diagnostic events, clinical manifestations, treatment and prophylaxis strategies, as well as disease- and treatment-related complications. Questionnaires were sent to 225 hemophilia treatment centers in the USA and Canada. Among 26% of responding centers, 294 individuals [4.4% of the registered children (200/4583) and 2.4% of adults (94/3809)] were diagnosed with one or more of the rare bleeding disorders (RBDs) included in this survey. The ethnic distribution for each disorder paralleled that of the general US population with the exception of the disproportionately large number of Latinos with FII deficiency. Only 5.4% of affected individuals were genotyped. An abnormal preoperative bleeding screen most often led to diagnosis. The most common coagulopathy was FVII deficiency; however, 40% of homozygous patients were asymptomatic. FX and FXIII deficiencies caused the most severe bleeding manifestations. Among all RBDs, the most common sites of bleeding were skin and mucus membranes. Multiple products were used to treat hemorrhage; however, half of the bleeding episodes required no therapy. The majority of patients suffered no long-term complications from hemorrhage. Treatment-related complications included viral seroconversion, anemia, allergic reactions and venous access device-related events. This registry provides the most comprehensive information to date about North American individuals with RBDs and could serve as an important resource for both basic scientist and clinician.

A case of orthodeoxia caused by an atrial septal aneurysm

Platypnea-orthodeoxia is an uncommon syndrome that may occur due to the postpneumonectomy state, cirrhosis of the liver, recurrent pulmonary embolism, and intracardiac shunting. We describe a patient who was found to have a positional change in desaturation after being admitted for dehydration. Workup revealed an atrial septal defect with aneurysm. Following surgical repair, the orthodeoxia resolved. Different mechanisms explain positional desaturation, such as atriovenous malformations at the lung base of cirrhotic patients. In an atrial septal defect, the increased shunting of blood across a malformed septum in an upright position may cause orthodeoxia. This case highlights the necessity of heightened awareness of this syndrome and the need for documenting orthostatic changes in cases of severe hypoxemia.

Annexin II and regulation of cell surface fibrinolysis

The regulated function of the fibrinolytic system is fundamental to the solubilization of fibrin-containing thrombi and to a number of other biologic processes. In recent years, several receptors, which serve to localize proteolytic activity on the cell surface, have been identified on endothelial cells, blood cells, neuronal cells, and tumor cells. One such receptor is annexin II, a calcium- and phospholipid-binding protein that serves as a profibrinolytic co-receptor for tissue plasminogen activator and plasminogen on endothelial cells. Accumulating evidence suggests that impaired cell surface fibrinolytic assembly could lead to progressive atherothrombotic disease. In addition, dysregulation of annexin II expression in acute promyelocytic leukemia is an important mechanism for the bleeding diathesis associated with this malignancy.