New Insights Into the Treatment of Glanzmann Thrombasthenia

Should HLA and HPA-matched platelet transfusions for patients with Glanzmann Thrombasthenia or Bernard-Soulier syndrome be standardized care? A Dutch survey and recommendations

BACKGROUND

Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) patients require frequent platelet transfusions and hence have an increased risk for alloimmunization against donor Human Leukocyte Antigens (HLA) when no HLA-matching is performed. Knowing that Human Platelet Antigens (HPA) are located on the platelet glycoproteins that can be absent in these patients, preventive HPA-matching may also be considered. Uniform recommendations on this topic lack in transfusion guidelines making standard practice unclear, therefore, we aimed to provide a framework for matched platelet transfusions.

STUDY DESIGN AND METHODS

We conducted a targeted literature search and a national survey of Dutch (pediatric) hematologists from July to September 2021.

RESULTS

We found 20 articles describing platelet transfusion policies in 483 GT-patients and 29 BSS-patients, both adults and children. Twenty surveys were returned for full analysis. All responders treated patients with platelet disorders, including GT (n = 36 reported) and BSS (n = 29 reported). Of respondents, 75% estimated the risk of antibody formation as "likely" for HLA and 65% for HPA. Formation of HLA antibodies was reported in 5 GT and in 5 BSS-patients, including one child. Fifteen respondents gave preventive HLA-matched platelets in elective setting (75%). Three respondents additionally matched for HPA in GT-patients (15%). Main argument for matched platelet transfusions was preventing alloimmunization to safeguard the effectivity of 'random' donor-platelets in acute settings.

CONCLUSION

Elective HLA-matching for GT and BSS-patients is already conducted by most Dutch (pediatric) hematologists. HPA-matching is mainly applied when HPA-antibodies are formed. Based on the current literature and the survey, recommendations are proposed.

Immune gene polymorphisms associated with poor response to platelet transfusion and recombinant factor VII administration in Glanzmann thrombasthenia

INTRODUCTION

Poor response to platelet and recombinant factor VII administration is a major problem in patients with Glanzmann Thrombasthenia (GT). The risk factors associated with poor response to treatment in these patients are unknown. Some genetic variations of cytokines may contribute to therapy resistance.

AIMS

We evaluated, for the first time, whether genetic polymorphisms on cytokine genes are related to poor treatment response in GT patients.

METHODS

We enrolled 30 patients with GT (15 resistant and 15 non-resistant) and 100 healthy controls. Gene polymorphisms of IL-10 and TNF-α were analysed using TaqMan Realtime PCR, and IL-1, IL-1R1 and IL-1RN were investigated with the RFLP method. In-silico analyses were performed to predict the potential impact of these polymorphisms.

RESULTS

In the resistant group, all patients had a variant of the IL-10 gene at the -1082 position (rs1800896), with a GG genotype that was significantly more frequent than the non-resistant group. Analysis between healthy controls and GT patients revealed a probable correlation between rs3783550, rs3783553, rs3917356 and rs2234463 and GT. The In-silico study indicated that TNF-α rs1800629 and IL-10 rs1800896 polymorphisms result in different allelic expressions which may contribute to poor response to therapy.

CONCLUSIONS

These findings suggest that polymorphisms in the IL-10 and IL-1 receptor antagonist genes may play a role in poor therapy response in GT patients. In addition, some polymorphisms in IL-1α, IL1-β, IL-1R1 and IL-R antagonists might be involved in the GT progression.

Antiplatelet mechanism of a subtilisin-like serine protease from Solanum tuberosum (StSBTc-3)

The aims of this study are to characterize the antiplatelet activity of StSBTc-3, a potato serine protease with fibrino (geno) lytic activity, and to provide information on its mechanism of action. The results obtained show that StSBTc-3 inhibits clot retraction and prevents platelet aggregation induced by thrombin, convulxin, and A23187. Platelet aggregation inhibition occurs in a dose-dependent manner and is not affected by inactivation of StSBTc-3 with the inhibitor of serine proteases phenylmethylsulfonyl fluoride (PMSF). In addition, StSBTc-3 reduces fibrinogen binding onto platelets. In-silico calculations show a high binding affinity between StSBTc-3 and human α2bβ3 integrin suggesting that the antiplatelet activity of StSBTc-3 could be associated with the fibronectin type III domain present in its amino acid sequence. Binding experiments show that StSBTc-3 binds to α2bβ3 preventing the interaction between α2bβ3 and fibrinogen and, consequently, inhibiting platelet aggregation. StSBTc-3 represents a promising compound to be considered as an alternative to commercially available drugs used in cardiovascular therapies.

In vitro characterization of rare anti-αIIbβ3 isoantibodies produced by patients with Glanzmann thrombasthenia that severely block fibrinogen binding and generate procoagulant platelets via complement activation

Background

Glanzmann thrombasthenia (GT) is a rare bleeding disorder caused by inherited defects of the platelet αIIbβ3 integrin. Platelet transfusions can be followed by an immune response that can block integrin function by interfering with fibrinogen binding.

Objectives

In this study, we aimed to determine the prevalence of such isoantibodies and better characterize their pathogenic properties.

Methods

Twelve patients with GT were evaluated for anti-αIIbβ3 isoantibodies. Sera from patients with GT with or without anti-αIIbβ3 isoantibodies were then used to study their in vitro effect on platelets from healthy donors. We used several approaches (IgG purification, immunofluorescence staining, and inhibition of signaling pathways) to characterize the pathogenic properties of the anti-αIIbβ3 isoantibodies.

Results

Only 2 samples were able to severely block integrin function. We observed that these 2 sera caused a reduction in platelet size similar to that observed when platelets become procoagulant. Mixing healthy donor platelets with patients' sera or purified IgGs led to microvesiculation, phosphatidylserine exposure, and induction of calcium influx. This was associated with an increase in procoagulant platelets. Pore formation and calcium entry were associated with complement activation, leading to the constitution of a membrane attack complex (MAC) with enhanced complement protein C5b-9 formation. This process was inhibited by the complement 5 inhibitor eculizumab and reduced by polyvalent human immunoglobulins.

Conclusion

Our data suggest that complement activation induced by rare blocking anti-αIIbβ3 isoantibodies may lead to the formation of a MAC with subsequent pore formation, resulting in calcium influx and procoagulant platelet phenotype.

Primary Hemostasis Disorders as a Cause of Heavy Menstrual Bleeding in Women of Reproductive Age

Heavy menstrual bleeding (HMB) is a common clinical condition affecting adolescent and adult women and compromising their quality of life. Primary hemostasis disorders, affecting platelet plug formation, can be the underlying cause of HMB. They comprise a heterogeneous group of diseases with Von Willebrand disease (VWD) being the most commonly diagnosed; other disorders in this group that have been linked to HMB include (a) Glanzmann thrombasthenia, (b) Bernard-Soulier syndrome, (c) Hermansky-Pudlak syndrome, (d) immune thrombocytopenia (ITP), and (e) Ehlers-Danlos syndromes (EDS) and hypermobility spectrum disorders (HSD). Diagnosing these diseases can be challenging, as the basic laboratory investigations can be within the normal range. Thus, identification of specific clinical features and a thorough hematologic workup can be very important, providing the correct diagnosis. Proper diagnosis of the underlying disorder is important, as management may vary accordingly. Although disease-specific management guidelines exist for some of these disorders such as VWD and ITP, due to the rarity of most primary hemostasis disorders, the best approach for the management of HMB in these women remains elusive. The goal of this study was to create an informative, comprehensive review of the primary hemostasis disorders that have been linked to HMB. This study provides a summary of the basic published information regarding epidemiology, pathophysiology, clinical phenotype, diagnosis, and treatment of HMB in those diseases and serves as a reference guide for further reading.

Detection of alloimmunization in Glanzmann Thrombasthenia and Bernard-Soulier Syndrome: Data from a Brazilian Center

INTRODUCTION

The Glanzmann Thrombasthenia (GT) and Bernard-Soulier Syndrome (BSS) are rare hereditary disorders of platelet function. Their treatment often requires platelet transfusion, which can lead to the development of alloantibodies.

OBJECTIVE

In this study, we aim to develop a strategy for alloantibody detection and to describe the frequency of alloimmunization in a patient population from a single center in southeastern Brazil.

METHODS

Samples from patients with GT or BSS were tested using the Platelet Immunofluorescence Test (PIFT). If a positive result was obtained, a confirmatory step using the Monoclonal Antibody Immobilization of Platelet Antigens (MAIPA) and Luminex bead-based platelet assay (PAKLx) was executed.

MAIN RESULTS

Among 11 patients with GT, we detected the presence of alloantibodies in 5 using PIFT, with confirmation through MAIPA and PAKLx in 2 (1 anti-HLA and 1 anti-HPA), resulting in a frequency of 18.1%. Among 4 patients with BSS, PIFT was positive in 3, with confirmation by MAIPA and PAKLx in 1 (anti-HLA), showing a frequency of 25%. The two patients with anti-HLA antibodies exhibited a panel reactive antibody (PRA-HLA) testing greater than 97%.

CONCLUSION

Our study highlights the importance of identifying platelet alloimmunization in this patient population. The proposed algorithm for platelet alloantibodies detection allows resource optimization.

Emergency management of patients with Glanzmann thrombasthenia: consensus recommendations from the French reference center for inherited platelet disorders

Glanzmann thrombasthenia (GT) is a genetic bleeding disorder characterised by severely reduced/absent platelet aggregation in response to multiple physiological agonists. The severity of bleeding in GT varies markedly, as does the emergency situations and complications encountered in patients. A number of emergency situations may occur in the context of GT, including spontaneous or provoked bleeding, such as surgery or childbirth. While general management principles apply in each of these settings, specific considerations are essential for the management of GT to avoid escalating minor bleeding events. These recommendations have been developed from a literature review and consensus from experts of the French Network for Inherited Platelet Disorders, the French Society of Emergency Medicine, representatives of patients' associations, and Orphanet to aid decision making and optimise clinical care by non-GT expert health professionals who encounter emergency situations in patients with GT.

Monozygotic twin cases of endometriosis with Glanzmann thrombasthenia: a case report and review of literature

BACKGROUND

Glanzmann thrombasthenia (GT) is a rare bleeding disorder with a high prevalence in communities where consanguineous marriages are mainstream. Endometriosis is a chronic inflammatory disease, and its risk increases in women with menstrual periods of longer than six days. The phenotypic expression of endometriosis is determined by the frequency and rate of the menstrual flow, as well as genetic and environmental factors.

RESULT AND CASE PRESENTATION

14-year-old monozygotic twin sisters with GT who developed ovarian endometriosis were referred to Hazrat Rasoul Hospital due to severe dysmenorrhea. In ultrasonic examination, endometrioma cysts were reported in both patients. They both went under endometrioma cystectomy, and the bleeding was managed using antifibrinolytic drugs, followed by recombinant activated coagulation factor VII. Both were discharged after 3 days. In the ultrasound examination performed one year after the surgery, ovaries were normal in the first twin, while the second twin had a 28 × 30 hemorrhagic cyst in the left ovary.

DISCUSSION AND CONCLUSION

Menstrual bleeding and genetic factors are two theories that could be related to GT and endometriosis association, and GT could be considered a risk factor for endometriosis.

Iron deficiency anemia and bleeding management in pediatric patients with Bernard-Soulier syndrome and Glanzmann Thrombasthenia: A single-institution analysis

INTRODUCTION

Frequent and severe bleeding events (SBE) in patients with inherited qualitative platelet disorders Bernard-Soulier Syndrome (BSS) and Glanzmann Thrombasthenia (GT) can lead to secondary iron deficiency anemia (IDA). SBE are primarily treated with platelet transfusions or recombinant activated factor VII (rFVIIa) infusions. The impact of IDA on bleeding management and disease outcomes is understudied.

AIM

To evaluate bleeding management, outcomes, and any association with IDA in pediatric patients with BSS and GT.

METHODS

Retrospective chart-review of pediatric patients with BSS or GT followed at a single hemophilia treatment center between 2007 and 2019.

RESULTS

We identified 14 patients with BSS (n = 2) or GT (n = 12). Patients received rFVIIa (7%), platelet transfusions (7%), or a combination of both (57%) for SBE. Eleven patients (79%) had IDA requiring oral and/or intravenous iron replacement and 50% required red blood cell transfusions. Due to recurrent SBE and refractory IDA, three patients (21%) received rFVIIa prophylaxis at 90 μg/kilogram 2-3 times/week for ≥15 months. Patients initiated on rFVIIa prophylaxis had a median baseline hemoglobin of 9.8 g/dL (min-max: 8.0-10.7 g/dL) compared to 11.7 g/dL (8.4-13.8 g/dL) for patients treated on-demand. Following initiation of rFVIIa prophylaxis, median hemoglobin and ferritin increased by 1.3 g/dL (0.7-2.5 g/dL) and 14.6 ng/mL (0.2-42.9 ng/mL), respectively, and bleeding rates were reduced by 7-78%.

CONCLUSION

IDA is a known complication of recurrent bleeding events in individuals with inherited bleeding disorders. Routine monitoring for IDA may help improve bleeding management and reduce bleed burden in BSS/GT.

How I manage pregnancy in women with Glanzmann thrombasthenia

Glanzmann thrombasthenia (GT) is a rare inherited platelet function disorder caused by a quantitative and/or qualitative defect of the αIIbβ3 integrin. Pregnancy and delivery is a recognized risk period for bleeding in women with GT. The newborn may also be affected by fetal and neonatal immune thrombocytopenia induced by the transplacental passage of maternal anti-αIIbβ3 antibodies, which can lead to severe hemorrhage and fetal loss. Pregnancy in GT women thus requires a multidisciplinary approach, including prepregnancy counseling, and a treatment plan for delivery for both the mother and child. In this article, we summarize the current knowledge on pregnancy in women with GT and describe how we manage this severe platelet disorder in our clinical practice.

Glanzmann's thrombasthenia during pregnancy complicated by large subchorionic hematoma managed with antifibrinolytics, human leukocyte antigen-matched platelet transfusion, and primary cesarean delivery: a case report

A 29-year-old primipara with Glanzmann's thrombasthenia presented for prenatal care at 8 weeks of gestation. Pregnancy remained uncomplicated until 22 weeks of gestation when a subchorionic hematoma, measuring 5.8 × 4.1 × 6.7 cm, was diagnosed and managed outpatient. At 28 weeks of gestation, the subchorionic hematoma was significantly expanding to 11 × 13 × 3.7 cm (∼30% of the placental surface). The patient was admitted for antepartum surveillance and steroid treatment. Fetal and maternal status were reassuring. At 36 weeks of gestation, there was active extravasation from the subchorionic hematoma, prompting interdisciplinary discussion with neonatal intensive care unit, blood bank, pharmacy, anesthesia, hematology, and the patient regarding her options. Immediate delivery risked platelet sensitization because of unavailable human leukocyte antigen-matched platelets. The patient opted for medical management with aminocaproic acid. At 37 weeks of gestation, she underwent a scheduled cesarean delivery. Human leukocyte antigen-matched platelets and additional aminocaproic acid were administered preoperatively. Intrapartum hemorrhage of 1200cc was controlled with uterotonics in addition to the above measures. Antifibrinolytics were continued. The neonate had an uncomplicated postpartum course. The patient had symptomatic anemia on postoperative day 1, which prompted red blood cell transfusion. Discharge was delayed until postoperative day 6 to further monitor her bleeding; oral antifibrinolytics were continued for 2 weeks. This case adds to the growing use of adjuvant medications, including antifibrinolytics such as aminocaproic acid and tranexamic acid, to reduce the reliance on platelet transfusion. This is critical for maintaining a favorable response to platelet transfusions and minimizing the risk of fetal neonatal alloimmune thrombocytopenia in current and subsequent pregnancies among women with lifelong bleeding disorders.

Gastrointestinal Bleeding in Congenital Bleeding Disorders

Gastrointestinal bleeding (GIB) is serious, intractable, and potentially life-threatening condition. There is considerable heterogeneity in GIB phenotypes among congenital bleeding disorders (CBDs), making GIB difficult to manage. Although GIB is rarely encountered in CBDs, its severity in some patients makes the need for a comprehensive and precise assessment of underlying factors and management approaches imperative. Initial evaluation of GIB begins with assessment of hematological status; GIB should be ruled out in patients with chronic anemia, and in presentations that include hematemesis, hematochezia, or melena. High-risk patients with recurrent GIB require urgent interventions such as replacement therapy for treatment of coagulation factor deficiency (CFD). However, the best management strategy for CFD-related bleeding remains controversial. While several investigations have identified CBDs as potential risk factors for GIB, research has focused on assessing the risks for individual factor deficiencies and other CBDs. This review highlights recent findings on the prevalence, management strategies, and alternative therapies of GIB related to CFDs, and platelet disorders.

Novel homozygous silent mutation of ITGB3 gene caused Glanzmann thrombasthenia

Glanzmann thrombasthenia (GT) is a rare inherited disease characterized by mucocutaneous bleeding due to the abnormalities in quantity or quality of platelet membrane GP IIb (CD41) or GP IIIa (CD61). GP IIb and GP IIIa are encoded by the ITGA2B and ITGB3 genes, respectively. Herein, we described a 7-year-old Chinese boy of the consanguineous couple who was diagnosed with GT based on the typical clinical manifestations, absence of blood clot retraction and the reduced expression of CD41 and CD61 in platelets. A homozygous silent variant c.1431C > T (p. G477=) of the ITGB3 gene was identified by the Whole-exome sequencing and confirmed by Sanger sequencing. The variant was predicted to affect the splicing. RT-PCR and sequencing revealed that the variant caused a deletion of 95 base pairs and frameshift, and subsequently created a premature stop codon in exon 10 of ITGB3 (p. G477Afs*30). It was indicated that the variant c.1431C > T (p. G477=) of ITGB3 was the cause for Glanzmann thrombasthenia. Our findings expanded the mutation spectrum and provided the information for the genetic counseling, prenatal diagnosis and preimplantation genetic testing (PGT).

Perioperative administration of recombinant activated factor VII in a Glanzmann's thrombasthenia patient with platelet refractoriness: case report

Glanzmann's Trombasthenia (GT) is a genetic disorder, that develops with a tendency toward bleeding and is characterized by the absence or decrease in platelet aggregation. Surgical bleeding may be difficult to control. Platelet transfusion is the main treatment, albeit refractoriness can occur. We describe the case of a patient with GT and platelet refractoriness, who was submitted to radical prostatectomy and dental extraction. The perioperative treatment with apheresis platelet concentrate and activated recombinant factor seven allowed the procedures to be performed uneventfully. We discuss the complexity of the case and the treatment option.

Use of rFVIIa in Preventing Recurrent Intra-articular Hemorrhages in a 15-Year-Old Patient With Glanzmann Thrombasthenia

Glanzmann thrombasthenia is a rare congenital thrombocytopathy. The first-line treatment in severe life-threatening bleeding is a transfusion of platelet concentrate or recombinant factor VIIa in the case of platelet transfusion refractoriness. We present the case of a 16-year-old boy with Glanzmann thrombasthenia who was admitted to hospital with severe bleeding into the quadriceps femoris muscle. At the age of 15 years, he was hospitalized again because of chronic bleeding into the right ankle joint, resulting in joint destruction. Here we give a scheme of management and treatment of this patient. Hemostatic therapy followed by radiosynovectomy of the right ankle joint and introduction of secondary preventive treatment with recombinant factor VIIa proved to be efficacious and safe.

Flow cytometric analysis of platelet surface glycoproteins in the diagnosis of thirty-two Turkish patients with Glanzmann thrombasthenia: a multicenter experience

Background/aim

Glanzmann thrombasthenia (GT) is a rare autosomal recessively inherited bleeding disorder characterized by the quantitative (type 1 and type 2) or qualitative (type 3) deficiency in platelet membrane glycoprotein (GP) IIb/IIIa (CD41a/CD61) fibrinogen receptors. In type 1, 2, and 3, CD41a/CD61 expression is 5%, 5%–20% and above 20%, respectively. In this study, diagnosis of GT was confirmed and subgroups were identified in 32 Turkish patients by flow cytometry analysis.

Materials and methods

CD41a/CD61 expression levels in platelet-rich plasma (PRP) obtained from peripheral venous EDTA blood samples were analyzed with a BD FACSCanto II flow cytometer (Becton Dickinson, Franklin Lakes, NJ, USA). GT subgroup analysis was performed by counting 50,000 events in the BD FACSDiva Software v6.1.3 program of the instrument.

Results

In the present study, in blood samples of 32 patients from 23 families with GT and 22 healthy controls, co-expression levels of CD41a and CD61 in PRP was analyzed. 12 out of 23 families were consistent with type 1 GT (52.2%), 4 were consistent with type 2 GT (17.4%), and 7 were consistent with type 3 GT (30.4%).

Conclusion

Especially due to consanguineous marriages, GT with various glycoprotein levels may be detected. As a result of the flow cytometry analysis of the present study with the highest GT patient population in Turkey, type 1 GT patients were the most common subgroup. In the determination of the GT subgroups; especially in the detection of type 3 GT, flow cytometry is the most sensitive glycoprotein analysis method. In addition to light transmission aggregometry, CD41a/CD61 study by flow cytometer confirms diagnosis when mutation analysis cannot be performed.

World Workshop on Oral Medicine VII: Bleeding control interventions for invasive dental procedures in patients with inherited functional platelet disorders: A systematic review

OBJECTIVES

The objective of this study was to determine bleeding control interventions (BCIs) that were reported to be effective in controlling postoperative bleeding in patients with inherited functional platelet disorders (IFPDs) undergoing invasive dental procedures.

STUDY DESIGN

We searched MEDLINE/PubMed, Embase, Cochrane Library (Wiley), and Scopus from 1960 through April 2020 for studies on patients with IFPD undergoing invasive dental procedures. Two reviewers conducted assessments independently.

RESULTS

We found a total of 620 nonduplicate published articles, of which 32 studies met our inclusion criteria. Management with BCI in patients with IFPD included in this systematic review was effective in 80.7% of treatment sessions. Local measures used intraoperatively were found to be effective. Three different protocols of BCI were noted; the most effective protocol consisted of antifibrinolytics, scaffold/matrix agents, and sutures (P < .01). An adjunct protocol consisting of a tissue sealant was also effective (P < .01). A third protocol of platelet transfusion and antifibrinolytics was ineffective in controlling postoperative bleeding in 4 of 6 dental sessions.

CONCLUSIONS

This systematic review supports the use of local measures intraoperatively and antifibrinolytics postoperatively. It also supports making decision regarding platelet transfusion based on the clinician's clinical judgment and medical history of the individual patient.

Profiling the Genetic and Molecular Characteristics of Glanzmann Thrombasthenia: Can It Guide Current and Future Therapies?

Glanzmann thrombasthenia (GT) is the most widely studied inherited disease of platelet function. Platelets fail to aggregate due to a defect in platelet-to-platelet attachment. The hemostatic plug fails to form and a moderate to severe bleeding diathesis results. Classically of autosomal recessive inheritance, GT is caused by defects within the ITGA2B and ITGB3 genes that encode the αIIbβ3 integrin expressed at high density on the platelet surface and also in intracellular pools. Activated αIIbβ3 acts as a receptor for fibrinogen and other adhesive proteins that hold platelets together in a thrombus. Over 50 years of careful clinical and biological investigation have provided important advances that have improved not only the quality of life of the patients but which have also contributed to an understanding of how αIIbβ3 functions. Despite major improvements in our knowledge of GT and its genetic causes, extensive biological and clinical variability with respect to the severity and intensity of bleeding remains poorly understood. I now scan the repertoire of ITGA2B and ITGB3 gene defects and highlight the wide genetic and biological heterogeneity within the type II and variant subgroups especially with regard to bleeding, clot retraction, the internal platelet Fg storage pool and the nature of the mutations causing the disease. I underline the continued importance of gene profiling and biological studies and emphasize the multifactorial etiology of the clinical expression of the disease. This is done in a manner to provide guidelines for future studies and future treatments of a disease that has not only aided research on rare diseases but also contributed to advances in antithrombotic therapy.

Weekly low-dose recombinant factor VIIa prophylaxis in Glanzmann thrombasthenia

Glanzmann thrombasthenia is an inherited disease causing bleeding episodes due to platelet dysfunction. The standard treatment for moderate-severe bleeding is platelet transfusion. Recombinant factor VIIa (rFVIIa) is successfully used in bleeding episodes and invasive procedures. Here, we present a patient with Glanzmann thrombasthenia, whose bleeding episodes could only be controlled by rFVIIa. The patient is a 28 years old male, who has had frequent bleeding episodes unresponsive to local hemostatic agents and tranexamic acid and had an anaphylactoid reaction to platelet transfusion. We started the patient on a low-dose (20 μg/kg) rFVIIa once a week. The patient has no spontaneous bleeding since then. This is the first case report of a Glanzmann thrombasthenia patient on routine prophylaxis with low-dose rFVIIa.

Glanzmann Thrombasthenia: Perspectives from Clinical Practice on Accurate Diagnosis and Optimal Treatment Strategies

Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder of fibrinogen-mediated platelet aggregation due to a quantitative or qualitative deficit of the α_IIbβ₃ integrin at the platelet surface membrane resulting from mutation(s) in ITGA2B and/or ITGB3. Patients tend to present in early childhood with easy bruising and mucocutaneous bleeding. The diagnostic process requires consideration of more common disorders of haemostasis and coagulation prior to confirming the disorder with platelet light transmission aggregation, flow cytometry of CD41 and CD61 expression, and/or exon sequencing of ITGA2B and ITGB3. Antifibrinolytic therapy, recombinant activated factor VII, and platelet transfusions are the mainstay of therapy, although the latter may trigger formation of anti-platelet antibodies in GT patients and inadvertent platelet-refractory disease. The management of these patients therefore remains complex, particularly in the context of trauma, labour and delivery, and perioperative care. Bone marrow transplantation remains the sole curative option, although the venue of gene therapy is being increasingly explored as a future alternative for definitive treatment of GT.

Inherited Platelet Disorders: An Updated Overview

Platelets play a major role in hemostasis as ppwell as in many other physiological and pathological processes. Accordingly, production of about 10¹¹ platelet per day as well as appropriate survival and functions are life essential events. Inherited platelet disorders (IPDs), affecting either platelet count or platelet functions, comprise a heterogenous group of about sixty rare diseases caused by molecular anomalies in many culprit genes. Their clinical relevance is highly variable according to the specific disease and even within the same type, ranging from almost negligible to life-threatening. Mucocutaneous bleeding diathesis (epistaxis, gum bleeding, purpura, menorrhagia), but also multisystemic disorders and/or malignancy comprise the clinical spectrum of IPDs. The early and accurate diagnosis of IPDs and a close patient medical follow-up is of great importance. A genotype-phenotype relationship in many IPDs makes a molecular diagnosis especially relevant to proper clinical management. Genetic diagnosis of IPDs has been greatly facilitated by the introduction of high throughput sequencing (HTS) techniques into mainstream investigation practice in these diseases. However, there are still unsolved ethical concerns on general genetic investigations. Patients should be informed and comprehend the potential implications of their genetic analysis. Unlike the progress in diagnosis, there have been no major advances in the clinical management of IPDs. Educational and preventive measures, few hemostatic drugs, platelet transfusions, thrombopoietin receptor agonists, and in life-threatening IPDs, allogeneic hematopoietic stem cell transplantation are therapeutic possibilities. Gene therapy may be a future option. Regular follow-up by a specialized hematology service with multidisciplinary support especially for syndromic IPDs is mandatory.

Non-viral ex vivo genome-editing in mouse bona fide hematopoietic stem cells with CRISPR/Cas9

We conducted two lines of genome-editing experiments of mouse hematopoietic stem cells (HSCs) with the clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated protein 9 (Cas9). First, to evaluate the genome-editing efficiency in mouse bona fide HSCs, we knocked out integrin alpha 2b (Itga2b) with Cas9 ribonucleoprotein (Cas9/RNP) and performed serial transplantation in mice. The knockout efficiency was estimated at approximately 15%. Second, giving an example of X-linked severe combined immunodeficiency (X-SCID) as a target genetic disease, we showed a proof-of-concept of universal gene correction, allowing rescue of most of X-SCID mutations, in a completely non-viral setting. We inserted partial cDNA of interleukin-2 receptor gamma chain (Il2rg) into intron 1 of Il2rg via non-homologous end-joining (NHEJ) with Cas9/RNP and a homology-independent targeted integration (HITI)-based construct. Repaired HSCs reconstituted T lymphocytes and thymuses in SCID mice. Our results show that a non-viral genome-editing of HSCs with CRISPR/Cas9 will help cure genetic diseases.

A novel heterozygous mutation flanking the fourth calcium-binding domain of the ITGA2B gene induces severe bleeding complications: a case report and literature review

Glanzmann thrombasthenia is a rare autosomal recessive genetic disease characterized by platelet aggregation dysfunction caused by a congenital defect of platelet membrane glycoprotein IIb/IIIa (integrin αIIbβ3). Integrin αIIbβ3, a calcium-dependent heterodimer, plays a critical role in platelet aggregation. We described a boy who was hospitalized with serious epistaxis at 10 months of age who had a history of repeated petechiae and spontaneous epistaxis since birth. Flow cytometry showed normal surface expression of platelet antigens. Genetic analysis and sequencing revealed the novel missense mutation c.G1252>T (p.Gly418Cys) in ITGA2B. This heterozygous amino acid mutation flanked the fourth calcium-binding domain and may interfere with integrin biogenesis via mechanisms other than merely altering cell surface expression. We discuss the heterogeneity of the genotype and phenotype with this atypical case and review the relevant literature on mutations adjacent to or within the calcium-binding domains in Glanzmann thrombasthenia.

Difficulty in controlling heavy menstrual bleeding at menarche in a patient with Glanzmann's thrombasthenia

Glanzmann's thrombasthenia is a rare inherited autosomal recessive bleeding disorder caused by platelet dysfunction. Adolescent girls with Glanzmann's thrombasthenia may experience problematic heavy menstrual bleeding beginning at menarche; this can be difficult to manage. Here, we report the case of an 11-year-old girl with Glanzmann's thrombasthenia who presented with heavy menstrual bleeding at menarche, which was difficult to control. The vaginal bleeding persisted and did not respond to a treatment with packed red blood cells (16 U total), platelet concentrates (70 U total), or administration (>50 doses) of recombinant activated factor VII (rFVIIa). Eventually, a combination of rFVIIa and hormonal therapy (a combined oral contraceptive pill) was introduced. The bleeding stopped at nearly 1 month from onset of menarche. Thereafter, the condition was managed by monthly subcutaneous administration of a GnRH agonist. Management of severe menorrhagia in adolescent patients with Glanzmann's thrombasthenia requires close collaboration with gynecologists or adolescent medicine specialists. More clinical studies are required to identify an effective combination of rFVIIa and hormonal therapy for this condition.

Gene Therapy for Inherited Bleeding Disorders

Decades of preclinical and clinical studies developing gene therapy for hemophilia are poised to bear fruit with current promising pivotal studies likely to lead to regulatory approval. However, this recent success should not obscure the multiple challenges that were overcome to reach this destination. Gene therapy for hemophilia A and B benefited from advancements in the general gene therapy field, such as the development of adeno-associated viral vectors, as well as disease-specific breakthroughs, like the identification of B-domain deleted factor VIII and hyperactive factor IX Padua. The gene therapy field has also benefited from hemophilia B clinical studies, which revealed for the first time critical safety concerns related to immune responses to the vector capsid not anticipated in preclinical models. Preclinical studies have also investigated gene transfer approaches for other rare inherited bleeding disorders, including factor VII deficiency, von Willebrand disease, and Glanzmann thrombasthenia. Here we review the successful gene therapy journey for hemophilia and pose some unanswered questions. We then discuss the current state of gene therapy for these other rare inherited bleeding disorders and how the lessons of hemophilia gene therapy may guide clinical development.

The Use of Recombinant Activated Factor VII in Patients with Glanzmann's Thrombasthenia

Platelet transfusion is the standard treatment to control or prevent bleeding in patients with Glanzmann's thrombasthenia (GT), but platelets are often unavailable. Recombinant activated factor VII (rFVIIa) is an effective alternative to platelets in patients with GT with past/present refractoriness to platelet transfusions and antibodies to platelets. However, there is an unmet need for an alternative to platelets in patients without antibodies. This report summarizes evidence of efficacy and safety of rFVIIa in patients with GT without refractoriness or antibodies to platelets from three different sources: the Glanzmann's Thrombasthenia Registry (GTR), published literature (January 01, 1999 to December 01, 2017), and the Novo Nordisk safety surveillance database. In the GTR, 133 patients received rFVIIa for the treatment of 333 bleeding episodes and prevention of bleeding in 157 surgical procedures. Overall efficacy rates were 79 and 88%, respectively, in patients treated for bleeding episodes or for the prevention of bleeding during surgery; effectiveness was generally similar across refractoriness/antibody status categories. Median dose per infusion of rFVIIa was close to that recommended for patients with GT (90 µg/kg). Data from 14 published case reports also demonstrated that rFVIIa is effective with an acceptable safety profile in patients with GT without antibodies to platelets. Analysis of adverse events reported in GTR and in Novo Nordisk safety surveillance database did not raise any new safety concerns. These data supported the label extension of rFVIIa to include cases where platelets are not readily available, which was approved by the European Medicines Agency in December 2018.

Thrombocytopathies: Not Just Aggregation Defects-The Clinical Relevance of Procoagulant Platelets

Platelets are active key players in haemostasis. Qualitative platelet dysfunctions result in thrombocytopathies variously characterized by defects of their adhesive and procoagulant activation endpoints. In this review, we summarize the traditional platelet defects in adhesion, secretion, and aggregation. In addition, we review the current knowledge about procoagulant platelets, focusing on their role in bleeding or thrombotic pathologies and their pharmaceutical modulation. Procoagulant activity is an important feature of platelet activation, which should be specifically evaluated during the investigation of a suspected thrombocytopathy.

Platelet Membrane Receptor Proteolysis: Implications for Platelet Function

The activities of adhesion and signaling receptors in platelets are controlled by several mechanisms. An important way of regulation is provided by proteolytic cleavage of several of these receptors, leading to either a gain or a loss of platelet function. The proteases involved are of different origins and types: (i) present as precursor in plasma, (ii) secreted into the plasma by activated platelets or other blood cells, or (iii) intracellularly activated and cleaving cytosolic receptor domains. We provide a comprehensive overview of the proteases acting on the platelet membrane. We describe how these are activated, which are their target proteins, and how their proteolytic activity modulates platelet functions. The review focuses on coagulation-related proteases, plasmin, matrix metalloproteinases, ADAM(TS) isoforms, cathepsins, caspases, and calpains. We also describe how the proteolytic activities are determined by different platelet populations in a thrombus and conversely how proteolysis contributes to the formation of such populations.

Excellent Outcome Following Sibling Peripheral Blood Hematopoietic Stem Cell Transplantation for Glanzmann Thrombasthenia: A Case Report

Glanzmann thrombasthenia (GT) is a rare autosomal recessive platelet disorder due to a qualitative or quantitative anomaly of the platelet membrane glycoprotein GPIIb/IIIa. Its clinical manifestations include mild to severe bleeding. GT diagnosis mainly depends on platelet function analysis, flow cytometry, and gene detection. Treatment methods include conservative symptomatic treatment and allogeneic hematopoietic stem cell transplantation (allo-HSCT). Allo-HSCT is the only clinical radical method for GT. Herein, we report a 2-year-old boy with GT successfully cured by related identical peripheral blood stem cell transplantation (PBSCT). The platelet disorder was corrected to a normal level after PBSCT, with no significant complication related to the transplantation. Hematopoietic stem cell transplantation with full-matched donor in early stage could be a treatment option for GT.

Characterization of Procoagulant COAT Platelets in Patients with Glanzmann Thrombasthenia

Patients affected by the rare Glanzmann thrombasthenia (GT) suffer from defective or low levels of the platelet-associated glycoprotein (GP) IIb/IIIa, which acts as a fibrinogen receptor, and have therefore an impaired ability to aggregate platelets. Because the procoagulant activity is a dichotomous facet of platelet activation, diverging from the aggregation endpoint, we were interested in characterizing the ability to generate procoagulant platelets in GT patients. Therefore, we investigated, by flow cytometry analysis, platelet functions in three GT patients as well as their ability to generate procoagulant collagen-and-thrombin (COAT) platelets upon combined activation with convulxin-plus-thrombin. In addition, we further characterized intracellular ion fluxes during the procoagulant response, using specific probes to monitor by flow cytometry kinetics of cytosolic calcium, sodium, and potassium ion fluxes. GT patients generated higher percentages of procoagulant COAT platelets compared to healthy donors. Moreover, they were able to mobilize higher levels of cytosolic calcium following convulxin-plus-thrombin activation, which is congruent with the greater procoagulant activity. Further investigations will dissect the role of GPIIb/IIIa outside-in signalling possibly implicated in the regulation of platelet procoagulant activity.

Bleeding Disorders Associated with Abnormal Platelets: Glanzmann Thrombasthenia and Bernard-Soulier Syndrome

Platelets, the smallest cells in the blood, are associated with hemostasis, bowel formation, tissue remodeling, and wound healing. Although the prevalence of inherited platelet disorders is not fully known, it is a rare disease group and is encountered in approximately between 10000 and 1000000. Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) are more frequently observed in inherited platelet disorders. In GT, the platelet aggregation stage due to deficiency or dysfunction of the platelet GPIIb/IIIa complex cannot take place. BSS is a platelet adhesion disorder due to the absence or abnormality of GPIb/IX complex on the platelet surface. If there is bleeding after easy bruising, mucous and oral cavities, menorrhagia, tooth extraction, tonsillectomy, or other surgical interventions, inherited platelet dysfunction should be considered if the platelet count is normal while the bleeding time is long. Firstly, other causes should be investigated by making differential diagnosis of GT and BSS. In this chapter, the definition, etiology, historical process, epidemiology, genetic basis, pathophysiology, clinical findings, diagnosis, differential diagnosis, and the follow-up and treatment approach of GT and BSS will be reviewed according to the current medical literature.

Management of Refractory Menstrual Bleeding in an Adolescent with Glanzmann Thrombasthenia: A Case Report and Review

Glanzmann Thrombasthenia is a rare bleeding disorder causing life-threatening bleeding at menarche in the adolescent female. Bleeding often necessitates admission and multiple blood transfusions. Due to the rarity of the disease, management of acute bleeding in new-onset menarche poses a particular challenge. A 12-year-old menarchial female had persistent vaginal bleeding despite multiple treatment modalities including aminocaproic acid, recombinant factor VIIa, intravenous estrogen, and gonadotropin receptor hormone agonists. Although the standard treatment of bleeding in patients with GT is primarily rFVIIa, new-onset menstrual bleeding in conjunction with an immature hypothalamic-pituitary-ovarian axis often requires expanding treatment to include multiple drug modalities. In our case, a two-step approach was necessary. The first is targeting the cessation of the first menses. The second is optimizing ongoing management of long-term control of heavy menstrual bleeding to achieve amenorrhea, prevent further hospital admissions, and avoid recurrent transfusions.

Disease Burden in Patients with Glanzmann's Thrombasthenia: Perspectives from the Glanzmann's Thrombasthenia Patient/Caregiver Questionnaire

Purpose

Glanzmann’s thrombasthenia (GT) is a rare bleeding disorder caused by a mutation in the αIIbβ3 integrin essential for optimal platelet function and hemostasis. The aim of this study was to identify the burden of GT on patients and caregivers through better understanding of the management and psychosocial impact of this disorder.

Patients and Methods

Participants for this online survey were recruited using a rare disease specialty recruiter from Comprehensive Health Education Services. Data were collected from January 31 through March 12, 2019. The questionnaire was designed to collect information regarding demographics, diagnosis, treatment, and psychosocial impact.

Results

Of the 45 respondents (24 patients and 21 caregivers), the majority were female (58%), white (64%), and employed full-time (53%) and had no family history of GT (64%). Many patients reported significant bruising at birth (76%), and the mean age at diagnosis was 2.6 years. About half of the patients experienced 1 bleed per day, and 13% had over 500 bleeds of any severity per year. Most bleeds were skin bruising or mouth bleeds, but patients also reported joint/muscle and gastrointestinal bleeds. Most patients reported receiving a platelet transfusion (82%), and some had developed platelet refractoriness (38%) or antibodies (32%). Common treatments were antifibrinolytics (82%) and recombinant activated factor VII (rFVIIa) (42%), likely due to the presence of antibodies. Many (58%) patients experienced issues with excessive bleeding at school; 38% reported missing school as a result. Female patients struggled to find a gynecologist with knowledge of the management of GT. Most patients were satisfied with the support they receive from their current partner (65%) and their friends (76%).

Conclusion

Most patients with GT are diagnosed early. Patients experience considerable psychosocial impact. Patient and physician education concerning treatment alternatives and the support of the GT community are critical.

Platelet Dysfunction Diseases and Conditions: Clinical Implications and Considerations

INTRODUCTION

Platelet diseases and dysfunction are taught early in medical school to all future physicians. Understanding of the coagulation cascade and hemostatic mechanisms has allowed for targeted pharmacological therapies that have been significantly impactful in clinical practice. Platelets are an early participant in hemostasis physiologically and under pathophysiological states.

METHODS

A review of literature involving platelet disfunction.

RESULTS

Various presentations of platelet diseases and dysfunction challenge clinicians and require a firm understanding of normal platelet function, drugs that mediate or modulate platelet effectiveness, and nonpharmacologic etiologies of platelet diseases and dysfunction with corresponding best practice treatment approaches.

CONCLUSION

This review summarizes normal and abnormal states associated with platelets and treatment strategies.

Perioperative considerations in a girl with Glanzmann thrombasthenia. Case report

Introduction: Glanzmann thromboasthenia is a rare congenital bleeding disorder caused by a mutation in platelet glycoprotein α-IIb and β3 encoding genes (ITGA2B; 607759 and ITGB3; 173470) in chromosomes 17q21.31 and 17q21.32 , respectively, which results in a qualitative or quantitative alteration of the platelet integrin αIIbβ3 (glycoprotein IIb/IIIa) receptor. Glanzmann thromboasthenia is classified as type I when less than 5% of glycoprotein αIIbβ3 is expressed, and as type II when more than 5% is expressed. Case presentation: Description of the perioperative management of a 13-year-old female patient with Glanzmann thromboasthenia who underwent endoscopic anterior bilateral ethmoidectomy. Management was centered on prophylactic platelet transfusion plus the use of tranexamic acid, as well as thromboelastographic determination of hemostasis. There were no bleeding complications during or after the procedure. Conclusions: Pediatric patients with Glanzmann thromboasthenia are at a high risk of perioperastive bleeding. Platelet transfusion is the best prophylactic and therapeutic alternative; however, even in the absence of anti-platelet antibodies, it may not be effective, and viscoelastic testing must be used for assessment during the surgical procedure in order to improve patient safety.

Successful Use of Hematopoietic Stem Cell Transplantation for 2 Pediatric Cases of Glanzmann Thrombasthenia and Review of the Literature

Glanzmann thrombasthenia is a rare platelet disorder characterized by an abnormal integrin receptor on the surface of platelets that results in the failure of platelets to aggregate. Currently, curative therapy is allogeneic hematopoietic stem cell transplantation (HSCT). The authors report 2 patients with Glanzmann thrombasthenia who successfully underwent allogeneic HSCT from unrelated donors, including one using umbilical cord blood stem cells. Although both patients had evidence of engraftment, hematopoietic recovery, and normalization of platelet aggregation, they also experienced several post-transplant complications. Allogeneic HSCT carries a significant risk of morbidity and mortality that should be considered before proceeding with the transplant.

Glanzmann's Thrombasthenia: How Listening to the Patient Is Sometimes the Simple Key to Good Medicine!

Introduction. Glanzmann's thrombasthenia is a rare clotting disorder caused by impaired platelet function. Lack of awareness of the appropriate management of rare medical conditions may lead to patient dissatisfaction and potentially poor treatment outcome. Case Report. A 78-year-old male with a history of Glanzmann's thrombasthenia was admitted to the trauma service following a fall in which he sustained a facial laceration as well as maxillary sinus and nasal fractures. He received DDAVP 20 mcg and tranexamic acid upon presentation to the emergency department (ED). In the ED, the patient requested administration of platelet transfusion but was refused due to a normal platelet count. During the course of his hospital stay, he complained of epistaxis and was noted to have a downtrending hemoglobin from 11.0 g/dl to 9.0 g/dl. The patient and his family were not comfortable when the discharge plan was finalized and demanded platelet transfusion (due to history of needing platelets in association with injuries or procedures in the past) was refused by the primary team as they continued to state that his platelet count is normal. On hospital day 3, hematology was consulted as the patient and his family were extremely angry and hematology recommended platelet transfusion. Further clinical information was not available as the patient was transferred to another facility per family request as they wanted to be at a center which had the patient's primary hematologist. Discussion. A delay in specialist consultation resulted in patient dissatisfaction and extended the length of stay. Patients with rare medical conditions and potential for major complications should be managed aggressively with appropriate specialist consultation to promote patient satisfaction and improve the overall quality of care. This case shows that as physicians it our duty to listen to our patient's concerns and involve them in the medical decision-making to provide optimal patient-centered care.

Platelet Disorders

After vascular injury and exposure of subendothelial matrix proteins to the intravascular space, mediators of hemostasis are triggered and allow for clot formation and restoration of vascular integrity. Platelets are the mediators of primary hemostasis, creating a platelet plug and allowing for initial cessation of bleeding. Platelet disorders, qualitative and quantitative, may result in bleeding signs and symptoms, particularly mucocutaneous bleeding such as epistaxis, bruising, petechiae, and heavy menstrual bleeding. Increasing evidence suggests that platelets have functional capabilities beyond hemostasis, but this review focuses solely on platelet hemostatic properties. Herein, normal platelet function as well as the effects of abnormal function and thrombocytopenia are reviewed.

Glanzmann thrombasthenia: genetic basis and clinical correlates

Glanzmann thrombasthenia (GT) is an autosomal recessive disorder of platelet aggregation caused by quantitative or qualitative defects in integrins αIIb and β3. These integrins are encoded by the ITGA2B and ITGB3 genes and form platelet glycoprotein (GP)IIb/IIIa, which acts as the principal platelet receptor for fibrinogen. Although there is variability in the clinical phenotype, most patients present with severe mucocutaneous bleeding at an early age. A classic pattern of abnormal platelet aggregation, platelet glycoprotein expression and molecular studies confirm the diagnosis. Management of bleeding is based on a combination of hemostatic agents including recombinant activated factor VII with or without platelet transfusions and antifibrinolytic agents. Refractory bleeding and platelet alloimmunization are common complications. In addition, pregnant patients pose unique management challenges. This review highlights clinical and molecular aspects in the approach to patients with GT, with particular emphasis on the significance of multidisciplinary care.

Glanzmann's thrombasthenia with spontaneous upper gastrointestinal bleeding: a case report

Glanzmann’s thrombasthenia (GT) is a rare bleeding disorder inherited in an autosomal recessive manner. The pathogenesis of GT mainly involves structural abnormalities and dysfunction of platelet membrane glycoprotein IIb/IIIa (integrin αIIbβ3). The most common symptoms of GT are various types of bleeding, including recurrent nasal bleeding, mucocutaneous bleeding, unremitting bleeding after injury or operation, and menorrhea in women. Such hemorrhage may be fatal in some patients. GT with spontaneous upper gastrointestinal bleeding is relatively rare. In the present report, we describe a middle-aged man who was hospitalized with spontaneous upper gastrointestinal bleeding. His main symptom was recurrent chronic and intermittent melena. Gastroscopy revealed oozing of blood in the gastric antrum wall. However, no obvious lesions such as erosion or ulceration were found. Upon further inspection, we found that the patient’s platelet aggregation was poor, and flow cytometry assay revealed low expression of platelet membrane integrin αIIbβ3. The patient was eventually diagnosed with GT and exhibited clinical improvement after active treatment.

RasGRP2 Structure, Function and Genetic Variants in Platelet Pathophysiology

RasGRP2 is calcium and diacylglycerol-regulated guanine nucleotide exchange factor I that activates Rap1, which is an essential signaling-knot in "inside-out" αIIbβ3 integrin activation in platelets. Inherited platelet function disorder caused by variants of RASGRP2 represents a new congenital bleeding disorder referred to as platelet-type bleeding disorder-18 (BDPLT18). We review here the structure of RasGRP2 and its functions in the pathophysiology of platelets and of the other cellular types that express it. We will also examine the different pathogenic variants reported so far as well as strategies for the diagnosis and management of patients with BDPLT18.

The use of prophylaxis in the treatment of rare bleeding disorders

Rare bleeding disorders (RBDs) are a heterogeneous group of coagulation factor deficiencies that include fibrinogen, prothrombin, α₂-antiplasmin, plasminogen activator inhibitor-1, and factors II, V, V/VIII, VII, X, XI and XIII. The incidence varies based upon the disorder and typically ranges from 1 in 500,000 to 1 per million population. Symptoms vary with the disorder and residual level of the clotting factor, and can range from relatively minor such as epistaxis, to life threatening, such as intracranial hemorrhage. Rapid treatment of bleeding episodes in individuals with severe bleeding phenotypes is essential to preserve life or limb and to prevent long-term sequelae; therapeutic options depend on the deficiency and range from plasma-derived (eg, fresh frozen plasma, prothrombin complex concentrates, factor X concentrate) to highly purified and recombinant single factor concentrates. The rarity of these disorders limits the feasibility of conventional prospective clinical trials; instead, clinicians rely upon registries, published case reports/series and experience to guide treatment. In some disorders, long-term prophylactic therapy is administered in response to the bleeding phenotype in an individual patient or based on the known natural history and severity of the deficiency. Intermittent prophylaxis, surrounding surgery, pregnancy, labor, and menstruation may be required to prevent or control excessive bleeding. This review summarizes therapeutic options, guidelines, recommendations and observations from the published literature for long-term, surgical, gynecological, and obstetric prophylaxis in deficiencies of fibrinogen; prothrombin; factors II, V, V/VIII, VII, X, XI and XIII; combined vitamin-K dependent factors; α2-antiplasmin; and plasminogen activator inhibitor 1. Platelet disorders including Glanzmann's thrombasthenia and Bernard-Soulier syndrome are also addressed.

Perioperative Hemostatic Management of a Pediatric Patient with Glanzmann Thrombasthenia Undergoing Osteoplastic Craniotomy and Hematoma Removal: A Case Report

Glanzmann thrombasthenia is an uncommon hereditary disease that involves an abnormal platelet function leading to complicated hemostatic problems. In situations of anticipated hemorrhage, irradiated apheresed platelets are the first line of treatment. In addition, a combination of recombinant factor VIIa and an antifibrinolytic agent such as tranexamic acid can be utilized to minimize bleeding. Here we are present stable management of a pediatric patient with Glanzmann thrombasthenia admitted for traumatic epidural hematoma removal. Due to the condition of the operation site, some blood loss was unavoidable. However, hemostasis was successfully controlled, and the patient was discharged without additional complications.

Leucocyte adhesion deficiency-A multicentre national experience

Leucocyte adhesion deficiency (LAD) is a rare, innate autosomal recessive immunodeficiency with three subtypes. Twenty-nine patients with LADs were diagnosed and treated in Israeli Medical Centers and in the Palestinian Authority. We discuss the phenotypic, genotypic and biochemical features of LAD-I, LAD-II and LAD-III diagnosed during the neonatal period and early infancy in 18, 6 and 5 patients, respectively. Consanguinity was frequent. Common features were severe infections of variable aetiology, excessive leukocytosis and delayed umbilical cord detachment. In LAD-I, the integrin CD18 expression varied from negligible to normal. However, CD11a expression was negligible in all tested patients, suggesting both CD11a and CD18 should be used to assess this subtype. LAD-II patients showed distinctive facial features, physical malformations, short stature and developmental delay. These patients show defective expression of SLeX (CD15a) on cell surface glycoproteins and lack of H antigen on erythroid cell surfaces resulting in Bombay blood group (hh). LAD-III showed intact but inactive β₂ integrins associated with severe infections and significant bleeding disorders caused by defective platelet aggregation and thrombocytopenia. We report four patients with two new unpublished mutations: two LAD-I patients with c.1099delG in ITGB2 and two LAD-III patients with c.1069C>T in FERMT3. LAD-I patients harbouring the c.119_128 deletion in ITGB2 seemed to have better outcomes as compared to other LAD-I patients. Eight patients with LAD-I and -III underwent successful haematopoietic stem cell transplantation. Cumulative survival was 75%, 50% and 40% for LAD-I, LAD-II and LAD-III, with a median follow-up of 4 (0.08-19), 3.25 (1-32) and 6 (0.08-8) years, respectively. Prenatal diagnosis is recommended in families with LAD syndromes.

ITGB (Integrin subunit beta) 3 mutation involved in pulmonary hemorrhage and osteopetrosis

We report on a previously healthy infant who presented with pulmonary hemorrhage due to a rare hematologic disorder. He also had imaging and laboratory studies suggestive of osteopetrosis. A genetic testing uncovered a previously known integrin gene possibly involving both hematologic and bone tissues; however, the latter has been described only in mouse models.