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

Abstract Glanzmannʼs 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.

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.

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.

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.

Profil épidémiologique des thrombopathies constitutionnelles dans l'ouest algérien / Epidemiological profile of constitutional thrombopathies in western Algeria

Introduction. Comme pour toutes les maladies rares ou maladies orphelines, l'étude des thrombopathies devrait être multicentrique pour recenser le maximum ou tous les patients dans une région ou dans le pays concerné. Notre étude a pour objectif d'évaluer la prévalence des thrombopathies constitutionnelles dans l'Ouest Algérien, et décrire ainsi les caractéristiques épidémiologiques de notre population. Patients et méthodes. Il s'agit d'une étude descriptive régionale du profil épidémiologique de 61 patients de l'Ouest Algérien présentant une thrombopathie constitutionnelle. Résultats. Dans notre étude a trouvé 34 thrombasthénies de Glanzmann (TG), 18thrombopathies de Jean Bernard Soulier (JBS), 08thrombopathies de May-Hegglin (MH) et un syndrome de Scott avec une prévalence globale de 1,8/1 million habitants. Conclusion. Notre travail nous a permis d'avoir un contexte global sur les thrombopathies constitutionnelles qui serait sans doute la base d'autres études de caractère clinique, biologique ou même moléculaire surtout en matière de recrutement de patients.

Introduction. As with all rare or orphan diseases, the study of inherited platelet disorders should be multicentric to identify as many or as few patients as possible in a given region or country. The aim of our study is to evaluate the prevalence of inherited platelet disorders in Western Algeria, and thus describe the epidemiological characteristics of our population. Patients and methods. This is a regional descriptive study of the epidemiological profile of 61 patients in Western Algeria with inherited platelet disorders. Results. In our study we found 34 Glanzmann thrombasthenias (TG), 18 Jean Bernard Soulier thrombopathies (JBS), 08 May-Hegglin thrombopathies (MH) and one Scott syndrome with an overall prevalence of 1.8/1 million inhabitants. Conclusion. Our work has allowed us to have a global context on inherited platelet disorders which would undoubtedly be the basis of other studies of clinical, biological or even molecular character especially in terms of patient recruitment.

Trombastenia de Glanzmann: conceptos clave de la enfermedad / Glanzmann thrombasthenia: key concepts of the disease

La trombastenia de Glanzmann (TG), es un trastorno autosómico recesivo en el cual hay una reducción grave o ausencia de la agregación plaquetaria. Se debe a las alteraciones cualitativas o cuantitativas de la integrina α IIb o de integrina β 3, codificados por los genes ITGA2B e ITGB3 y relacionadas con la glicoproteína IIb/IIIa, que intervienen en la activación plaquetaria. La mayor incidencia de TG ha sido reportada en la población judía-iraquí, pero también se ha presentado en Israel, Jordania, Arabia saudita, Italia y, en menor número, en familias gitanas y pakistaníes. A pesar de ser poco frecuente, este trastorno se debe sospechar en casos de trastornos hemorrágicos graves espontáneos o inducidos por traumatismos, que varían desde hemorragias gastrointestinales y mucocutáneas, como epistaxis y hemorragias gingivales recurrentes de difícil manejo, las cuales son potencialmente mortales y en más del 75 por ciento de los casos requieren transfusión sanguínea o plaquetaria. Para realizar la confirmación del diagnóstico, los hallazgos de laboratorio se caracterizan por tiempos de sangrado prolongados, retracción del coágulo disminuida y respuestas anormales de agregación plaquetaria a estímulos fisiológicos. Aunque, actualmente no existe una cura para la enfermedad, el tratamiento adecuado con transfusiones plaquetarias y en caso de refractariedad, el uso del factor VIIa, permiten un buen pronóstico para los pacientes. Aún queda mucho por estudiar en estos casos debido a esto se están realizando nuevos estudios para la posibilidad de otros tratamientos, entre ellos la terapia génica plaquetaria(AU)

Glanzmann's thrombasthenia (GT) is an autosomal recessive disorder in which there is a severe reduction or absence of platelet aggregation. It is due to the qualitative or quantitative alterations of integrin #945; IIb or integrin #946; 3, encoded by the ITGA2B and ITGB3 genes and related to glycoprotein IIb / IIIa, which intervene in platelet activation. The highest incidence of GT has been reported in the Jewish-Iraqi population, but it has also been reported in Israel, Jordan, Saudi Arabia, Italy, and in smaller numbers in Gypsy and Pakistani families. Despite being uncommon, this disorder should be suspected in cases of severe spontaneous or trauma-induced bleeding disorders, ranging from gastrointestinal and mucocutaneous hemorrhages such as epistaxis and recurrent, difficult to manage gingival hemorrhages, which are potentially fatal and more than 75 percent of cases require blood or platelet transfusion. To confirm the diagnosis, the laboratory findings are characterized by prolonged bleeding times, decreased clot retraction and abnormal platelet aggregation responses to physiological stimuli. Although there is currently no cure for the disease, adequate treatments with platelet transfusions and in case of refractoriness, the use of factor VIIa, allow a good prognosis for patients. There is still much to study in these cases, because of this, new studies are being conducted for the possibility of other treatments, including platelet gene therapy(AU)

Glanzmann Thrombasthenia in a Korean Patient: A Postoperative Intracranial Hemorrhagic Diasthesis in a Patient with a Rupture of a Cerebral Aneurysm

BACKGROUND: Glanzmann thrombasthenia (GT) is a rare disease with severe insufficiency of platelet function. There are no reports of GT associated with a cerebral hemorrhage. CASE REPORT: A 45-year-old woman had a stuporous mentality. Her computed tomographic (CT) angiography revealed a rupture of the posterior cerebral artery aneurysm. Hunt-Hess grade was 4 points and Fisher grade was 3 points. A clipping of the aneurysm was performed and proceeded to external ventricular drainage for hydrocephalus after 6 days. But, a new hemorrhage was detected several times via a follow-up brain CT. Various blood tests were conducted to evaluate the bleeding tendency, and the GT was diagnosed with PFA-200. The ventriculoperitoneal shunt was performed after the platelets transfusion, and she was discharged without other complications. CONCLUSION: With nonspecific and recurrent intracranial hemorrhage, a GT should be included in the differential diagnosis, which is important in controlling bleeding during the surgery.

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).

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.

Mutation screening and prenatal diagnosis of a pedigree with Glanzmann's thrombasthenia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Mutation screening was performed in a pedigree of Glanzmann's thrombasthenia (GT) and prenatal diagnosis was performed.</p><p><b>METHODS</b>In this study, reverse transcription-PCR-sequencing and PCR-sequencing, as well as restriction fragment length polymorphism(RFLP) and A/T-cloned-sequencing, were used to screen the ITGA2B and ITGB3 mutation in a pedigree with Glanzmann's thrombasthenia in the RNA and DNA level. Prenatal diagnosis was performed for this pedigree.</p><p><b>RESULTS</b>Deletion of 99 bps was found in the cDNA of the patient in the pedigree, leading to deletion of 33 codons (from codon 160 to 192). After genomic analysis, the patient was found to be a compound heterozygote of c.374C to G mutation and intron 4(IVS-4) + 5 G to C mutation. The two mutations were inherited from the parents. IVS-4 + 5 G to C mutation was a point mutation in the splice site, while c.374C to G mutation was out of the splice site. But both of them resulted in the same splice pattern in RNA. The two mutations were novel mutations which have not been reported in Human Gene Mutation Database (HGMD) and the mutation data base of Glanzmann's thrombasthenia. The results of ITGB3 gene screening is normal in the proband and his parents.</p><p><b>CONCLUSION</b>Two novel mutation, c.374C to G and IVS-4 + 5 G to C were found in this study, which might be the cause of GT in the pedigree.</p>

Identification of compound heterozygous mutations in the ITGA2B gene in a Chinese patient with Glanzmann thrombasthenia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Glanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder characterized by the tendency to hemorrhage and the inability of platelets to aggregate in response to agonists. GT is caused by a defect of the platelet glycoprotein IIb/IIIa complex. The objective of this study was to describe the clinical features and the genetic cause of GT in a 6-year-old girl from south China.</p><p><b>METHODS</b>A three-generation family was studied. The proband patient aged 6 years and her parents undertook examinations of platelet counts, blood film, bleeding time, platelet aggregation, and flow cytometry. All coding exons of the ITGA2B and ITGB3 genes were amplified by polymerase chain reaction (PCR), and direct sequencing was performed for mutational screening on the patient and normal controls consisted of 52 healthy blood donors. Reverse transcription PCR was conducted to test for exon skipping.</p><p><b>RESULTS</b>The proposita patient showed dispersing platelets, prolonged bleeding time, and severely reduced platelet aggregation in response to the physiological agonists adenosine diphosphate (ADP), epinephrine, collagen, and ristocetin. Flow cytometric measurements showed that the contents of alphaIIb and beta3 were significantly decreased. Sequencing results demonstrated two different types of heterozygous mutations existed in the alphaIIb gene (c.2930delG and IVS15-1delG). The compound mutations were also confirmed in the patient's mother and father separately.</p><p><b>CONCLUSIONS</b>The alphaIIbbeta3 deficiency of the proband was caused by two compound ITGA2B mutations, which were first reported in Chinese GT patients. The IVS15-1delG was first confirmed to cause an exon skipping.</p>

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.

Glanzmann's thrombasthenia and pregnancy

Glanzmann's thrombasthenia is rare autosomal recessive platelet disorder caused by abnormal platelet glycoprotein complex [GP IIb-IIIa] leading to excessive mucosal bleeding. Patients with Glanzmann's thrombasthenia may present with hemorrhagic symptoms including mucosal bleeding, easy bruising and post-surgical bleeding. We report a 37-year old lady, who underwent a cesarean section at term. She received recombinant factor VIIa at the time of surgery. She had uneventful post operative period and she was discharged home in good general conditions

Anesthetic experience for orthopedic surgery on a patient with Glanzmann's thrombasthenia refractory to platelet transfusion: A case report / 대한마취과학회지

Glanzmann's thrombasthenia is an autosomal recessive bleeding disorder caused by qualitative or quantitative abnormalities of the platelet glycoprotein IIb/IIIa (GP IIb/IIIa), which can lead to excessive bleeding. Glanzmann thrombasthenia is associated with clinical variability, with some patients only having minimal bruising and others having frequent, severe and potentially fatal hemorrhages. Platelet transfusions, which used to be the standard treatment, may lead to the development of antibodies to HLA and/or GPIIb/IIIa, thereby rendering future transfusions ineffective. Glanzmann's thrombasthenia can be a severe hemorrhagic disease; however, the prognosis is excellent with careful supportive care. In this case, administering allogenic plateletpheresis to patients with Glanzmann's thrombasthenia who were refractory to platelet transfusions was found to be successful during bone surgeries.