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

ABSTRACT 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.

Successful outcomes of surgery procedures in patient with Glanzmann´s Thrombasthenia

We report a 35-year-old female patient with Glanzmann's thrombasthenia (GT) and severe anemia due to abnormal uterine bleeding secondary to uterine myomatosis. She required several admissions of red blood cells and platelet transfusions. An elective subtotal hysterectomy with salpingo-oophorectomy was proposed and recombinant factor VII was required. Surgical and postoperative outcomes were successful, without surgical complications, bleeding, or hemogram alterations. 4 years later, she required tooth extraction because of periodontal disease and pulp necrosis. In Peru, reports of GT patients requiring major and minor surgical procedures are lacking, given the low disease prevalence and the difficulties related to surgery. The report of these successful cases becomes relevant to continue improving GT management.

Presentamos el caso de una paciente de 35 años con trombastenia de Glanzmann (GT) y anemia severa por sangrado uterino anormal secundario a miomatosis uterina. Requirió varias admisiones de transfusiones de glóbulos rojos y plaquetas. Se propuso histerectomía subtotal electiva con salpingo-ooforectomía y se requirió factor VII recombinante. Los resultados quirúrgicos y postoperatorios fueron exitosos, sin complicaciones quirúrgicas, sangrado ni alteraciones del hemograma. 4 años después, requirió extracción dental por enfermedad periodontal y necrosis pulpar. En Perú faltan reportes de pacientes con GT que requieran procedimientos quirúrgicos mayores y menores, dada la baja prevalencia de la enfermedad y las dificultades relacionadas con la cirugía. El reporte de estos casos de éxito cobra relevancia para seguir mejorando la gestión de GT

Neonatal Glanzmann thrombasthenia: a case report and literature review / 中国新生儿科杂志

Objective:To study the clinical features and genotypes of neonatal Glanzmann thrombasthenia(NGT).Methods:A male neonate with NGT admitted to the Department of Neonatology of our hospital was retrospectively reviewed. CNKI, Wangfang database, VIP, the Chinese Medical Journal Full Text database, PubMed and Embase database were searched using key words '(neonate OR newborn) AND (Glanzmann thrombasthenia)' both in English and Chinese. The clinical features and genotypes of NGT were summarized and analyzed.Results:A male full-term neonate was admitted to our hospital for mass on the forehead and ecchymosis and petechiae on the body within half an hour after birth. He gradually developed subgaleal hemorrhage and severe anemia. Platelet count, mean platelet volume and coagulation functions were normal. The platelet aggregation test indicated decreased platelet aggregation rate induced by arachidonic acid and adenosine diphosphate. Genetic testing revealed two heterozygous mutations in the patient's ITGA2B gene: NM_000419.4: c.886G>A(p.Gly296Arg) and NM_000419.4: c.2855dup(p.Phe953Valfs*83). A total of 42 literature involving 44 patients (our case included) with NGT were retrieved. 33 cases (75.0%) of NGT showed ecchymosis or petechiae on the first day after birth. For 13 cases with detailed information, 5 cases with severe anemia were given erythrocyte and plasma transfusion and platelet transfusion was given in 1 case. 4 cases had homozygous variants and 4 cases showed compound heterozygous variants. 10 cases had follow-up records, including 2 cases without any bleeding and 8 cases with varying degrees of bleeding during follow-up. No deaths were reported.Conclusions:Neonates with ecchymosis and petechiae in the early postnatal period should be suspected of NGT. Blood transfusion is preferred when the indication for transfusion is met.

Manejo de la trombastenia de Glanzmann durante el embarazo: reporte de un caso y revisión de la literatura / Management of Glanzmann's thrombasthenia during pregnancy: a case report and literature review

Resumen Objetivo: Reportar el caso de una paciente con trombastenia de Glanzmann que recibe manejo con transfusión de plaquetas con factor VII activado y realizar una revisión de la literatura referente al tratamiento y el pronóstico de esta patología durante la gestación. Método: Se presenta el caso de una paciente de 27 años con trombastenia de Glanzmann y embarazo de 33 semanas, con cesárea al término sin complicaciones. Se realizó una búsqueda en las bases de datos Medline vía PubMed, Lilacs, SciELO y ScienceDirect; se incluyeron reportes de caso, series de casos y revisiones bibliográficas hasta 2021. Resultados: Se encontraron 21 artículos, con 23 casos reportados. Los embarazos se presentaron entre la tercera y la cuarta décadas de la vida, siendo la mayoría pacientes con anticuerpos frente a antígenos plaquetarios (43,4% de los casos). El principal manejo fue con transfusión plaquetaria. Conclusiones: La trombastenia de Glanzmann durante el embarazo es infrecuente y se asocia a eventos hemorrágicos. La presencia de anticuerpos frente a antígenos plaquetarios condiciona el manejo con mayor riesgo de complicaciones perinatales. No tiene un enfoque terapéutico unificado, siendo el de elección la transfusión de plaquetas y como segunda línea el factor VII activado.

Abstract Objective: To report the case of a patient with Glanzmann's thrombasthenia who receives management with platelet transfusion with activated factor VII and a literature review regarding the treatment and prognosis of this pathology during pregnancy. Method: We present the case of a 27 year old patient with Glanzmann's thrombasthenia and a 33-week pregnancy, with a cesarean section at term without complications. Medline databases were searched via PubMed, Lilacs, SciELO and ScienceDirect; case reports, case series and bibliographic reviews were included until 2021. Results: A total of 21 articles were found, with 23 reported cases; the pregnancies occurred between the third and fourth decades of life, the majority being patients with anti-platelet antigen antibodies in 43.4% of the cases. The main management was with platelet transfusion. Conclusions: Glanzmann's thrombasthenia during pregnancy is rare and is associated with hemorrhagic events. The presence of anti-platelet antigen antibodies conditions management with a higher risk of perinatal complications. It does not have a unified therapeutic approach, with platelet transfusion being the management of choice and activated factor VII as second line.

Glanzmann thrombasthenia: Use of hemocoagulase (BotroClot) for arrest of bleeding during a primary tooth endodontic procedure

The Rationale: Glanzmann thrombasthenia is a rare platelet disorder affecting 0.0001% of the population. Dentists may often be unaware of this condition, and manipulation of soft tissue can lead to grave consequences, which may even result in fatality. Patient Concerns: In this case report, a 4?year?old patient with Glanzmann thrombasthenia reported to the department with a chief complaint of a discoloured tooth. Clinical Findings: On examination, 51 was nonvital, and pulpectomy was the treatment planned. The non?vital anterior tooth was treated with a pulpectomy procedure. There was uncontrolled bleeding during the procedure. Treatment: A topical solution of BotroClot was used to arrest the bleeding, and obturation was completed following that. The post?operative period was uneventful. Take?away Lessons: Case report explored the use of a topical hemostatic agent to arrest bleeding from the canal. This case report warrants eliciting a thorough medical history before any dental procedure.

High-power laser for periodontal surgery in a patient with glanzmann thrombasthenia / Laser de alta potência para cirurgia periodontal em paciente com trombastenia de glanzmann

Background: Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder characterized by platelet function impairment. Considering that the oral cavity is highly vascularized and performing some local hemostatic maneuvers may be difficult, GT patients are at high risk for hemorrhage related to invasive oral procedures. This study aimed to present an alternative method for periodontal surgery in a young GT patient. Case Report: A 15-year-old female GT patient with a recent history of excessive bleeding following dental surgeries was referred to a public dental center, presenting gingival hyperplasia. The procedure was performed using a high-power laser (HPL), and except for local anesthesia with epinephrine, no further hemostatic agent was necessary. Conclusion: According to the case, the HPL seems to be an efficient tool for preventing perioperative bleeding in GT patients submitted to minor oral surgeries(AU)

Introdução: A trombastenia de Glanzmann (TG) é uma doença autossômica recessiva rara caracterizada por comprometimento da função plaquetária. Tendo em vista que a cavidade oral é altamente vascularizada e a realização de algumas manobras hemostáticas locais pode ser difícil, pacientes com TG apresentam alto risco de hemorragia relacionada a procedimentos orais invasivos. Este artigo teve como objetivo apresentar uma técnica alternativa para cirurgia periodontal em um paciente jovem com TG. Relato de Caso: Paciente com TG, sexo feminino, 15 anos, com história recente de sangramento excessivo relacionado a cirurgias odontológicas prévias, foi encaminhada a um centro odontológico público apresentando hiperplasia gengival. O procedimento de remoção foi realizado com laser de alta potência e, com exceção da anestesia local com epinefrina, nenhum outro agente hemostático foi necessário. Conclusão: De acordo com o caso, o laser de alta potência parece ser uma ferramenta eficiente na prevenção de sangramento perioperatório em pacientes com TG submetidos a pequenas cirurgias orais(AU)

Effects of the ITGA2B Nonsense Mutation (c.2659C > T, p.Q887X) on Platelet Function in a Mouse Model of Glanzmann's Thrombasthenia Generated with CRISPR/Cas9 Technology / 中国实验血液学杂志

OBJECTIVE@#To construct a mouse model of Glanzmann's thrombasthenia (GT) with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation by CRISPR/Cas9 technology, and then further explore the expression and function of glycoprotein αIIbβ3 on the surface of platelet membrane.@*METHODS@#The donor oligonucleotide and gRNA vector were designed and synthesized according to the ITGA2B gene sequence. The gRNA and Cas9 mRNA were injected into fertilized eggs with donor oligonucleotide and then sent back to the oviduct of surrogate mouse. Positive F0 mice were confirmed by PCR genotyping and sequence analysis after birth. The F1 generation of heterozygous GT mice were obtained by PCR and sequencing from F0 bred with WT mice, and then homozygous GT mice and WT mice were obtained by mating with each other. The phenotype of the model was then further verified by detecting tail hemorrhage time, saphenous vein bleeding time, platelet aggregation, expression and function of αIIbβ3 on the surface of platelet.@*RESULTS@#The bleeding time of GT mice was significantly longer than that of WT mice (P<0.01). Induced by collagen, thrombin, and adenosine diphosphate (ADP), platelet aggregation in GT mice was significantly inhibited (P<0.01, P<0.01, P<0.05). Flow cytometry analysis showed that the expression of αIIbβ3 on the platelet surface of GT mice decreased significantly compared with WT mice (P<0.01), and binding amounts of activated platelets to fibrinogen were significantly reduced after thrombin stimulation (P<0.01). The spreading area of platelet on fibrinogen in GT mice was significantly smaller than that in WT mice (P<0.05).@*CONCLUSION@#A GT mouse model with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation has been established successfully by CRISPR/Cas9 technology. The aggregation function of platelet in this model is defective, which is consistent with GT performance.

Consenso mexicano para el diagnóstico y tratamiento de la trombastenia de Glanzmann / Mexican consensus on the diagnosis and treatment of Glanzmann thrombasthenia

Resumen Las plaquetas tienen un papel central en diferentes escenarios fisiológicos, incluyendo la hemostasia; se unen unas con otras en la agregación plaquetaria, lo cual permite formar un coágulo plaquetario. Para que la agregación sea apropiada se requiere del complejo glicoproteico IIb/IIIa (GPIIb/IIIa) en la superficie plaquetaria. Toda alteración funcional plaquetaria, hereditaria o adquirida, impide la formación adecuada del coágulo y se manifiesta como hemorragia. Las enfermedades plaquetarias hereditarias son raras y, hasta recientemente, fueron ignoradas. Una de las más reconocidas y estudiadas es la trombastenia de Glanzmann (TG), entidad en la cual el número de plaquetas puede ser normal pero la función está alterada. Es un padecimiento autosómico y recesivo que causa hemorragia de diferente intensidad toda la vida y en la cual el problema radica en precisamente en la GPIIb/IIIa. Las hemorragias son típicamente mucocutáneas: equimosis, púrpura, epistaxis, gingivorragia; menos frecuentes son la hemorragia gastrointestinal, hemartrosis o en sistema nervioso central. La hiperpolimenorrea es común en las mujeres y llega a ser tan importante que amerita transfusiones en la menarca. La TG afecta a todos los grupos étnicos y su prevalencia varía entre 1/40,000 y 1/400,000. A pesar de esta información acerca de la TG en el mundo, hay pocas guías o recomendaciones basadas en la opinión de expertos y experiencias unicéntricas. En México la TG es rara y no se cuenta con una recomendación general para su diagnóstico y tratamiento. El objetivo de este documento fue establecer un consenso y hacer sugerencias generales para su diagnóstico y tratamiento.

Abstract Platelets have a central role in several physiological scenarios including hemostasis. Platelets bind each other during platelet aggregation allowing the proper formation of the clot; to be appropriate, platelet aggregation requires the glycoproteic complex IIb/IIIa (GPIIb/IIIa). Every platelet function abnormality both, congenital or acquired, impedes clot formation and favors bleeding episodes. Hereditary platelet abnormalities are rare and, until recently, they were almost ignored. Among these disorders, Glanzmann Thrombasthenia (GT) is a widely recognized abnormality in which platelet counts may be normal, but their function is affected. GT is an autosomal, recessive disease that causes life-long bleeding of different intensity. Main biochemical abnormality resides in GPIIb/IIIa. Bleeding is typically mucocutaneous: easy bruising, purpura, and nose and gum bleeds; less frequently are gastrointestinal bleeds, hemarthrosis, or intracranial. Menorrhagia and hyperpolymenorrhea are common findings in in women and may be the cause of anemia requiring blood transfusions at fertile age. GT affects all ethnic groups and its prevalence ranges between 1/40,000 to 1/400,000. Despite this worldwide information regarding GT, only a few guidelines and recommendations have been published, most of them based on expert opinions. In Mexico, GT is rare and there is not a general recommendation regarding its diagnosis and treatment. The aim of this document was to establish a consensus to suggest a general guideline for the diagnosis and treatment of GT in Mexico.

Trastornos plaquetarios hereditarios poco frecuentes: patología molecular y aspectos diagnósticos / Infrequent hereditary platelets disorders: molecular pathology and diagnostic aspects

Introducción: Las plaquetas tienen una función clave en la hemostasia primaria a través de cuatro mecanismos fundamentales: adhesión, agregación, secreción y actividad procoagulante, todos controlados genéticamente por más de 50 genes asociados que han sido identificados. Las manifestaciones clínicas en las alteraciones hereditarias de las plaquetas suelen ser variables; aunque estas alteraciones de la coagulación suelen presentarse con una trombocitopenia notoria, también pueden exhibir trombocitopatías, en las cuales la capacidad hemostática de las plaquetas resulta afectada sin variar su número. Por tanto, existen gran variedad de manifestaciones fenotípicas y mutaciones en relación con la función plaquetaria, algunas de las cuales se explicarán más adelante. Objetivo: Realizar revisión práctica sobre mutaciones plaquetarias hereditarias de baja incidencia y destacar la importancia de su conocimiento, correcto diagnóstico, y tratamiento precoz. Métodos: Se realizó revisión literaria en inglés y españolen MEDLINE, EMBASE, Lilacs y ScienceDirect desde mayo 2019 hasta abril 2020, con el uso de combinación de palabras clave y términos MeSH relacionados con trombastenia, genética médica, hemostasis, agregación plaquetaria, trombopoyesis. Se efectuó análisis y resumen de la bibliografía revisada. Conclusión: Entre las alteraciones hereditarias de las plaquetas se pueden encontrar defectos en todos los mecanismos en que participan; sin embargo, la confirmación diagnóstica sigue siendo complicada por el tiempo y el costo que representa lo que ocasiona diagnósticos inadecuados que impactan en el manejo clínico y la evolución(AU)

Introduction: Platelets have a key role in primary hemostasis through four main mechanisms: adhesion, aggregation, secretion and procoagulant activity, all of these controlled by over 50 associated genes that have been identified. Clinical signs of hereditary platelets alterations are usually variable; even though these disorders of hemostasis generally course with a notorious thrombocytopenia, they also might have thrombocytopathies, in which the hemostatic capacity of platelets is affected without altering its number. According to this, there's a great variety of phenotypic manifestations and mutations that affect platelet function, some of these will be explained later on. Objective: To make a practical review of hereditary platelets mutations that have low incidence in population and to highlight the importance of knowing about them, how to diagnose them and early treatment. Methods: A review of literature in both Spanish and English, was done based on MEDLINE, EMBASE, Lilacs and ScienceDirect, during May 2019 and April 2020 using key words and MeSH terms such as thrombasthenia, medical genetics, hemostasis, platelets aggregation, thromopoiesis. Then, an analysis and summary of the reviewed bibliography was carried out. Conclusion: Among the hereditary alterations of platelets, many defects can be found in every mechanism involved; however, diagnostic confirmation is still complicated due to time and cost, causing inaccurate diagnoses that impact on clinic management and evolution(AU)

Perioperative considerations in a girl with Glanzmann thrombasthenia. Case report / Consideraciones perioperatorias en niña con trombastenia de Glanzmann. Reporte de caso

Abstract 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 I7q21.31 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. Conclusiones 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.

Resumen Introducción La trombastenia de Glanzmann es un trastorno hemorrágico congénito infrecuente, causado por mutación en los genes que codifican las glucoproteínas plaquetarias α-IIb (ITGA2B; 607759) y β3 (ITGB3; 173470) en los cromosomas I7q2i.3i y I7q2i.32, respectivamente, alterando cualitativa o cuantitativamente al receptor plaquetario de integrina αIIbβ3 (glucoproteína IIb/IIIa). La trombastenia de Glanzmann se clasifica como tipo I cuando se expresa menos del 5 % de la glucoproteína αIIbβ3 y como tipo II, cuando es mayor al 5 %. Presentación del caso Se describe el manejo perioperatorio de una paciente de 13 años de edad con trombastenia de Glanzmann, sometida a etmoidectomía anterior bilateral endoscópica. El manejo se centró en la transfusión profiláctica de plaquetas y ácido tranexámico, así como en la evaluación de la hemostasia con tromboelastografía. No hubo complicaciones hemorrágicas durante y después del procedimiento. Conclusiones Los pacientes pediátricos con trombastenia de Glanzmann tienen alto riesgo de hemorragia perioperatoria. La transfusión de plaquetas es la mejor alternativa profiláctica y terapéutica; sin embargo, incluso en ausencia de anticuerpos antiplaquetarios, puede no ser efectiva y debe evaluarse mediante pruebas viscoelásticas durante los procedimientos quirúrgicos para mejorar la seguridad del paciente.

Study on molecular pathogenesis for a case of Glanzmann′s thrombasthenia / 临床检验杂志

Objective@#To investigate the molecular pathogenesis for a patient with Glanzmann thrombasthenia (GT). @*Methods@#The peripheral blood of a patient with Glanzmann′s thrombasthenia was collected, and the genetic mutations were detected by gene sequencing technology. The mutant plasmids were prepared by PCR site-directed mutagenesis and transfected into CHO-K1 cells of Chinese hamster ovary to construct in vitro eukaryotic expression system. The expressions of αⅡb and β3 protein subunits in CHO-K1 cells were detected by western blot. The expression levels of αⅡb and β3 in cellular membrane and cytoplasm of CHO-K1 cells were detected by flow cytometry. The expression and distribution of αⅡb and β3 in CHO-K1 cells were observed by immunofluorescent labeling under microscope. @*Results@#This patient was diagnosed with type Ⅱ GT. Gene sequencing revealed two mutations in ITGB3 gene which has not been reported in the literature. ITGB3 c.1495 T＞C missense mutation resulted in replacement of cysteine no.499 by arginine (p.C499R). ITGB3 c.1728 delC code shift mutation resulted in a change in the amino acid synthesis initiated by the β3 protein subunit serine no.577 and terminated by the 92nd amino acid following these changes. The results of western blotting showed that the synthesis and expression of primary structures of αⅡb and β3 were detectable in the lysates of mutant CHO-K1 cells. The results of flow cytometry showed that no expression of β3 on the surface and intracellular of mutant CHO-K1 cells was observed. Under fluorescence microscopy no distribution of β3 protein subunit was displayed in mutant CHO-K1 cells. @*Conclusion@#The mutation of ITGB3 c.1728 del C or ITGB3 c.1495 T＞C should be relevant to the cause of GT in this patient. The mutation of ITGB3 c.1728 del C and ITGB3 c.1495 T＞C seems not to affect the formation of the primary structure of β3 protein subunit, but did affect the formation of its high-level structure.

Mutational analysis of 3 Glanzmann's thrombasthenia pedigrees / 中华检验医学杂志

Objective To explore the molecular pathogenesis of 3 Glanzmann's thrombasthenia pedigree by using bioinformatics software and provide evidence for in vitro experiments. Methods The genetic analysis of 3 pedigree diagnosed as Glanzmann's thrombasthenia was carried out. Clustalx-2.1 win software was used to analyze the conservatism of mutant sites in homologous sequences. Bioinformatics software such as PolyPhen-2, PROVEAN, SIFT and Mutationtaster was used to analyze the biological effect of mutation. SPDBV software constructed the molecular structure model of mutant protein and evaluated the influence of mutation on protein structure. Results The "new mutations" found in 3 Glanzmann's thrombasthenia pedigree were ITGA2B:c. 814G>C (p. Val272Leu), ITGA2B:c. 432G>A (p. Trp144Ter) and ACTN1:c. 2458A>G (p. Ile820Val). All three mutations were highly conserved among homologous species. Mutationtaster software showed that 3 new mutations were likely pathogenic. PolyPhen-2 and PROVEAN software showed ITGA2B p.Val272Leu and ACTN1 p.Ile820Val were benign and SIFT software showed that ITGA2B p. Val272Leu were likely pathogenic, while ACTN1 p. Ile820Val is benign. The result of SPDBV software showed that the Val272 of ITGA2B was transformed to Leu, neutralizing all the original hydrogen bond. The Trp144 of ITGA2B is transformed to Ter, resulting in the truncated proteins with only 113 amino acid residues. All these mutations affected the molecular structure of GPⅡb, resulting in a decrease ofGPⅡb/Ⅲa expression. When the Ile820 of ACTN1 is transformed to Val, onlyretained the hydrogen bond of Ile820 and Asp822, neutralized the rest hydrogen bond, whichaffected the molecular structure and protein function of ACTN1. Conclusion The mutations of ITGA2B:c.814G>C (p.VAL272LEU), ITGA2B:c.432G>A (p.Trp144Ter) and ACTN1:c.2458A>G (p.Ile820Val) are pathogenic.

Pathogenesis and prenatal diagnosis of hereditary Glanzmann thrombasthenia / 临床儿科杂志

Objective To explore the gene sequencing and prenatal diagnosis of Glanzmann thrombasthenia (GT). Methods The blood samples were drawn from one case of phenotype GT pediatric patient, patient’s parents, and one normal control. The amniotic lfuid and cord blood from the fetus of patient’s mother were collected. When the fetus was born 2 days, the blood was drawn. The coagulation routine test and platelet aggregation test were performed. The expression of platelet membrane glycoprotein (GP) IIb and GPIIIa were tested by lfow cytometry. Microsatellite technology is used to determine whether fetal cord blood is contaminated with maternal cells. The expressed region and the junctional zone between exon and introns of GPIIb and GPIIIa were ampliifed by PCR technology from blood sample of patient, patient’s parents, and fetus’s cord and 2 days after birth. The PCR products were then subjected to DNA sequencing. Results Adenosine diphosphate (ADP) cannot induce the platelet aggregation in the patient. The max rate of the platelet aggregation in the fetus’s cord blood was half of the normal. However, the max aggregation rate induced by ADP in the blood sample of parents and fetus 2 days after birth were equal to normal. The mean lfuorescence intensity (MnX) of platelet membrane GPIIb and GPIIIa in the patient were 10%and nearly zero of the normal control, respectively, while those in the parents, the fetus’s cord blood and 2 days after birth were more than 90%and 30%to 50%of the normal control. The cast-off cells in amniotic lfuid and the DNA in cord blood analysis by microsatellite technology conifrmed that the amniotic lfuid and cord blood not contaminated by maternal cells. Gene analysis showed the heterozygosis mutation in exon6 A3829→C and exon9 G42186→A of the patient’s GPIIIa led to the amino acid heterozygosis mutation in GPIIIaHis281→Tyr and Cys400→Pro. These two mutations came from the father and the mother separately. However, there was only one heterozygosis mutation in exon9 G42186→A in the cast-off cells in amniotic lfuid, the fetus’s cord and blood 2 days after birth. Conclusion This GT patient have double heterozygosis mutation. The fetus has heterozygosis mutation conifrmed after birth.

Manejo integral hematológico-odontológico en trombastenia de Glanzmann / Hematology-dental integrated management in Glanzmann thrombasthenia

La trombastenia de Glanzmann (TG) es una enfermedad hematológica de baja frecuencia, tiene un patrón de herencia autosómica recesiva. Se caracteriza por alteración de la función plaquetaria. Se puede presentar como petequias, epistaxis, hemorragias gastrointestinales y gingivales. Se reporta el caso de un paciente de género masculino que acude a servicio odontológico universitario anexo a hospital de cuarto nivel por presentar gingivorragia severa y aflojamiento de algunos dientes. El manejo integral del paciente muestra la importancia del trabajo multidisciplinario. (Acta Med Colomb 2015; 40: 58-61).

Glanzmann's thrombasthenia (GT) is a low frequency hematologic disease with an autosomal recessive inheritance pattern. It is characterized by impaired platelet function. It It can occur as petechiae, epistaxis and gastrointestinal and gingival bleeding. The case of a male patient who attends University Dental Service annex to fourth level hospital for presenting severe gingival bleeding and loosening of some teeth is reported. The integral management of the patient shows the importance of multidisciplinary work. (Acta Med Colomb 2015; 40: 58-61).

An update on pathogenesis and treatment of Glanzmann thrombasthenia / 临床儿科杂志

Glanzmann thrombasthenia (GT) is an inherited disease of platelet function disorders characterized by mucocutaneous bleeding due to platelets failed to aggregate in response to physiologic stimuli. GT is a rare inherited disease and caused by quantitative or qualitative deifciencies of an integrin receptor GPⅡb/Ⅲa for adhesive proteins. There is no uniifed treatment strategy available so far for GT. This review summarizes the update of pathogenesis treatment progresses in GT.

A Case of Glanzmann's Thrombasthenia Successfully Managed after Tonsillectomy / 임상소아혈액종양

Glanzmann's thrombasthenia (GT) is a rare autosomal recessive disease and platelet function disorder, in which platelet membrane GP IIb/ IIIa complex is defective and platelet aggregation is undeveloped. GT is characterized by mucocutaneous hemorrhages, such as, epistaxis, purpura, gingival bleeding, and menorrhagia, severe bleeding complications during surgery. We report the case of a 6-year-old boy with GT who underwent tonsillectomy. Here, we focus on perioperative hemostatic management using recombinant factor VIIa, fibrin glue and hemostat materials.

A Case of Glanzmann's Thrombasthenia Successfully Managed after Tonsillectomy / 임상소아혈액종양

Glanzmann's thrombasthenia (GT) is a rare autosomal recessive disease and platelet function disorder, in which platelet membrane GP IIb/ IIIa complex is defective and platelet aggregation is undeveloped. GT is characterized by mucocutaneous hemorrhages, such as, epistaxis, purpura, gingival bleeding, and menorrhagia, severe bleeding complications during surgery. We report the case of a 6-year-old boy with GT who underwent tonsillectomy. Here, we focus on perioperative hemostatic management using recombinant factor VIIa, fibrin glue and hemostat materials.

Conduta no perioperatório de paciente pediátrico com trombastenia de glanzmann durante adenoidectomia / Perioperative management of a pediatric patient with glanzmann's thrombasthenia during adenoidectomy / Conducta en el perioperatorio de paciente pediátrico con trombastenia de glanzmann durante la adenoidectomía

JUSTIFICATIVA E OBJETIVOS: Trombastenia de Glanzmann (TG) é uma doença autossômica recessivamente hereditária das plaquetas. Não há nenhum tratamento específico. A transfusão de plaquetas é atualmente o tratamento padrão quando o sangramento não responde a medidas locais e/ou a medicamentos antifibrinolíticos, podendo, entretanto, resultar em aloimunização. O fator VII recombinante ativado (rFVIIa) pode ser usado para evitar a transfusão recorrente de plaquetas. RELATO DE CASO: Apresentamos um tratamento precoce com dose baixa de rFVIIa associada à transfusão de plaquetas em um caso pediátrico (cinco anos de idade), com diagnóstico de TG e apresentando sangramento prolongado durante adenoidectomia eletiva. Uma dose total de 1.200 mg (60 µg.kg-1) de rFVIIa obteve sucesso em estancar o sangramento, o que pode ser aceito como uma dose baixa. CONCLUSÕES: Relatos de casos podem encorajar o uso de tratamento precoce com baixas doses de rFVIIa em hemorragias graves que não estacam a despeito da transfusão de plaquetas e na prevenção de sangramento em procedimentos cirúrgicos em pacientes com TG. Estudos adicionais são necessários para definir a dose mínima eficaz. Portanto, as tentativas para determinar a dose eficaz mais baixa desse composto devem ser incentivadas consideando o resultado deste caso em face de restrições financeiras no sistema de saúde.

BACKGROUND AND OBJECTIVE: Glanzmann's thrombasthenia (GT) is an autosomal recessively inherited platelet disorder. There is not any specific treatment. Platelet transfusion is currently the standard treatment when bleeding does not respond to local measures and/or antifibrinolytic treatment, although it may result in alloimmunization. Recombinant activated factor VII (rFVIIa) might be used to avoid recurrent platelet transfusion. CASE REPORT: We present early treatment with low-dose rFVIIa additional to platelet transfusion in a 5-year-old pediatric case with diagnosis of GT who developed prolonged bleeding under an elective adenoidectomy surgery. A total dose of 1,200 µg (60 µg.kg-1) rFVIIa could successfully stop bleeding, what can be accepted as low dose usage. CONCLUSIONS: Such case reports may encourage the use of early treatment with low doses of rFVIIa in severe bleeds that did not stop despite of platelet transfusion, as well as in preventing bleeding in surgical procedures in patients with GT. Actually, additional studies are needed to define the minimal effective dose and attempts to determine the lowest effective dose may be encouraged by the result of this case, considering financial restrictions in the health care system.

JUSTIFICATIVA Y OBJETIVOS: La Trombastenia de Glanzmann (TG) es una enfermedad autosómica recesivamente hereditaria de las plaquetas. No hay ningún tratamiento específico. La transfusión de plaquetas es hoy por hoy, el tratamiento estándar cuando el sangramiento no responde a medidas locales y/o a medicamentos antifibrinolíticos, pudiendo sin embargo, resultar en una aloinmunización. El factor VII recombinante activado (rFVIIa) puede ser usado para evitar la transfusión recurrente de plaquetas. RELATO DE CASO: Presentamos aquí un rápido tratamiento con una dosis baja de rFVIIa asociada a la transfusión de plaquetas en un caso pediátrico (5 años de edad), con diagnóstico de TG y presentando un sangramiento prolongado durante la adenoidectomía electiva. Una dosis total de 1.200 mg (60 µg.kg-1) de rFVIIa tuvo éxito al estancar el sangramiento, lo que puede aceptarse como una dosis baja. CONCLUSIONES: Relatos de casos pueden estimular el uso de tratamiento rápido con bajas dosis de rFVIIa en las hemorragias graves que no estancan, pese a la transfusión de plaquetas y a la prevención de sangramiento en los procedimientos quirúrgicos en pacientes con TG. Sin embargo, estudios adicionales se hacen necesarios para definir la dosis mínima eficaz. Por tanto, los intentos para determinar la dosis eficaz más baja de un compuesto tan caro deben ser incentivados debido al resultado de este caso cuando existan restricciones financieras en el sistema de Sanidad.

Utilidad clínica de la agregometría plaquetaria / Clinical utility of platelet aggregometry

Resumen: La acción de las plaquetas en la hemostasia primaria comprende la adhesión a losvasos sanguíneos afectados, la activación, la secreción del contenido granular, y posteriormente,la agregación plaquetaria para la formación del tapón hemostático primario. Bajo las condicionesfisiológicas de flujo vascular, estos procesos requieren la acción sinérgica de varias proteínasy receptores plaquetarios, como también de agonistas que inducen la activación plaquetaria.Por ello, las mutaciones de los genes que codifican para moléculas y receptores de superficieimplicados en estos procesos darán origen a desórdenes hemorrágicos como la enfermedad devon Willebrand, la trombastenia de Glanzmann, el síndrome de Bernard Soulier y la deficienciade gránulos plaquetarios, entre otros. El diagnóstico de estas enfermedades se realiza medianteensayos de función plaquetaria que simulan los procesos fisiológicos de activación, adhesión,liberación del contenido granular y agregación. Una de las pruebas de función plaquetaria másutilizada es la agregometría. En este artículo de revisión se describe la utilidad de esta prueba parael diagnóstico de desórdenes hemorrágicos hereditarios y del síndrome de la plaqueta pegajosa,un desorden trombótico hereditario caracterizado por hiperagregabilidad. Adicionalmente, se revisa el fundamento de esta prueba, las condiciones preanalíticas, analíticas y posaanaliticas, analiticas y poanaliticas las indicaciones las contraindicaciones y la interpetación de los resultados.

Abstract: The role of platelets in primary hemostasis involves their adherence to sites of vessel injury, activation, secretion of platelet granule content, and finally, aggregation to form the primaryhemostatic plug. Under physiologic conditions of vascular flow, these processes require thesynergistic action of several proteins and platelet receptors, and also the action of physiologicalagonists that stimulate the activation of the platelets. As a result, hereditary mutations of genescodifying for molecules and surface receptors implied in primary hemostasis will be expressedas hemorrhagic disorders, including von Willebrand disease, Glanzmann thrombasthenia,Bernard Soulier syndrome, storage pool diseases, among others. The diagnosis of these diseases is possible through platelet function assays that resemble the physiological processesof activation, adhesion, release of granule content, and aggregation. Platelet aggregometry isone of the most frequently used tests. This review article intends to describe the utility of plateletaggregometry for the diagnosis of hereditary hemostatic disorders and sticky platelet syndrome, a hereditary thrombotic disorder characterized by increased platelet aggregability. In addition, the fundamentals of the test, the pre-analytical, analytical and post-analytical conditions, the test indications, contraindications and results interpretation are discussed.

Antiplatelet antibodies in cases of Glanzmann's thrombasthenia with and without a history of multiple platelet transfusion.

Antiplatelet antibodies are known to be present in a wide spectrum of patients, which include chronic Idiopathic Thrombocytopenic Purpura (ITP), infections, etc., including Glanzmann's thrombasthenia (GT) patients who receive multiple platelet transfusions. The presence of natural antibodies to platelet receptors is not studied in cases of GT. We studied the antiplatelet antibodies in 23 patients with GT, 15 of which had received multiple transfusions and eight that had not received transfusions, along with 50 cases of chronic ITP. The prevalence and specificity of platelet-bound antibodies were detected by inhibition assays using O-group platelets on flow cytometry. The mean antiplatelet antibodies in 15 patients of GT who had not received transfusions and eight patients with multiple transfusions was 8427 + 2131.88 and 9038 + 2856 antibodies/platelet, respectively, while in case of the 50 ITP patients studied, it was 22166 + 5616 antibodies/platelet (Normal Range 1500–3200 antibodies/platelet). We conclude that GT patients who have not received transfusions may develop antiplatelet antibodies to the missing/abnormal receptor. Whether this is due to a molecular mimicry or due to some other mechanism needs to be explored.