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.

A rare case of glanzmann thrombasthenia with concomitant factor VII deficiency.

Glanzmann thrombasthenia and clotting factor VII deficiency are rare autosomal recessive bleeding disorders. But the occurrence of both in the same person is an extremely rare phenomenon. Here, we present the case of a young female from Sindh, Pakistan that got diagnosed with Glanzmann thrombasthenia and concomitant moderate factor VII deficiency, a combination not previously reported in the country. The patient exhibited typical clinical manifestations including menorrhagia, nasal bleeds, and prolonged bleeding after minor injuries, compounded by a positive family history and consanguinity. Laboratory investigations revealed marked anemia, prolonged bleeding time, and abnormal platelet aggregation studies consistent with Glanzmann thrombasthenia. The identification of this rare combination relied on comprehensive clinical evaluation, emphasizing the importance of family history in suspected cases. Management involved platelet transfusions, tranexamic acid, and Factor VII replacement, resulting in clinical improvement.

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-ß, IL-1R1 and IL-R antagonists might be involved in the GT progression.

Antagonistic Roles of Human Platelet Integrin αIIbß3 and Chemokines in Regulating Neutrophil Activation and Fate on Arterial Thrombi Under Flow.

BACKGROUND: Platelets and neutrophils are the first blood cells accumulating at sites of arterial thrombus formation, and both cell types contribute to the pathology of thrombotic events. We aimed to identify key interaction mechanisms between these cells using microfluidic approaches. METHODS: Whole-blood perfusion was performed over a collagen surface at arterial shear rate. Platelet and leukocyte (in majority neutrophil) activation were microscopically visualized using fluorescent markers. The contributions of platelet-adhesive receptors (integrin, P-selectin, CD40L) and chemokines were studied by using inhibitors or antibodies and using blood from patients with GT (Glanzmann thrombasthenia) lacking platelet-expressed αIIbß3. RESULTS: We observed (1) an unknown role of activated platelet integrin αIIbß3 preventing leukocyte adhesion, which was overcome by short-term flow disturbance provoking massive adhesion; (2) that platelet-expressed CD40L controls the crawling pattern and thrombus fidelity of the cells on a thrombus; (3) that continued secretion of platelet substances promotes activation of identified neutrophils, as assessed by (fMLP [N-formylmethionyl-leucyl-phenylalanine, a potent chemotactic agent and leukocyte activator] induced) [Ca2+]i rises and antigen expression; (4) and that platelet-released chemokines activate the adhered cells in the order of CXCL7>CCL5>CXCL4. Furthermore, postsilencing of the platelets in a thrombus suppressed the leukocyte activation. However, the leukocytes on thrombi did no more than limitedly form neutrophil extracellular traps, unless stimulated with phorbol ester or lipopolysaccharide. CONCLUSIONS: Together, these findings reveal a multifaceted regulation of adhesion and activation of neutrophils by platelets in a thrombus, with a balanced role of several platelet-adhesive receptors and a promoting role of platelet-released substances. This multivalent nature of neutrophil-thrombus interactions offers novel prospects for pharmacological intervention.

Molecular dynamics simulations corroborate recombinant expression studies carried out on three αIIb ß-propeller mutations reported in Indian Glanzmann thrombasthenia patients.

Mutations in the αIIb ß-propeller domain have long been known to disrupt heterodimerization and intracellular trafficking of αIIbß3 complexes leading to diminished surface expression and/or function, resulting in Glanzmann thrombasthenia. Our previous study on three ß-propeller mutations, namely G128S, S287L, and G357S, showed variable defects in protein transport correlated with the patient's clinical phenotypes. Pulse-chase experiments revealed differences in αIIbß3 complex maturation among the three mutations. Hence, the current study aims to correlate conformational changes caused by each one of them. Evolutionary conservation analysis, stability analysis, and molecular dynamics simulations of the three mutant structures were carried out. Stability analysis revealed that, while G128S and G357S mutations destabilized the ß-propeller structure, S287L retained the stability. Wild-type and mutant ß-propeller structures, when subjected to molecular dynamics simulations, confirmed that G128S and G357S were both destabilizing in nature when compared with the wild-type and S287L based on several parameters studied, like RMSD, RMSF, Rg, FEL, PCA, secondary structure, and hydrogen bonds. In our previous study, we demonstrated that mutant S287L αIIbß3 complexes were more stable than the wild-type αIIbß3 complexes, as evidenced in pulse-chase experiments. These findings corroborate variable intracellular fates of mutant αIIbß3 complexes as a result of these ß-propeller mutations.

Multidisciplinary management of a pregnancy complicated by Glanzmann thrombasthenia: A case report.

BACKGROUND: Glanzmann thrombasthenia (GT) is a rare, autosomal recessive disorder of platelet glycoprotein IIb-IIIa receptors. Pregnant patients with GT are at increased risk of maternal and fetal bleeding. There is a paucity of literature on the peripartum management of patients. CASE DESCRIPTION: We present the antepartum through the postpartum course of a patient with GT who was managed by a multidisciplinary approach that included communication across maternal-fetal medicine, hematology, transfusion medicine, and anesthesiology services. In addition to routine prepartum obstetric imaging and hematologic laboratory studies, we proactively monitored the patient for anti-platelet antibodies every 4-6 weeks to gauge the risk for neonatal alloimmune thrombocytopenia. Furthermore, we prioritized uterotonics, tranexamic acid, and transfusion of HLA-matched platelets to manage bleeding for mother and fetus intrapartum through the postpartum periods. CONCLUSION: To date, there are limited guidelines for managing bleeding or preventing alloimmunization during pregnancy in patients with GT. Here, we present a complex case with aggressive management of bleeding prophylactically for the mother while serially monitoring both mother and fetus for peripartum bleeding risks and events. Moreover, future studies warrant continued evaluation of these approaches to mitigate increased bleeding risks in subsequent pregnancies.

Current status and future prospects of activated recombinant coagulation factor VIIa, NovoSeven®, in the treatment of haemophilia and rare bleeding disorders.

rFVIIa, a human recombinant activated coagulation factor VII, has been used worldwide for more than two decades for the treatment of bleeding episodes and prevention of bleeding in patients undergoing surgery/invasive procedures with congenital haemophilia A or B with inhibitors (CHwI A or B), acquired haemophilia (AH), congenital factor VII deficiency and Glanzmann thrombasthenia (GT), refractory to platelet transfusion. The approved dosage, administration and indication of rFVIIa in the US, Europe and Japan differ, depending on the needs of the patient population and regulatory practices. This review presents an overview of the current status and future prospects, including that from a Japanese perspective, of using rFVIIa in the treatment of approved indications. The efficacy and safety of rFVIIa in the approved indications has been demonstrated in several randomised and observational studies and data from registries. The overall incidence of thrombosis across all approved indications in a retrospective safety assessment of clinical trials and registries, prelicensure studies and postmarketing surveillance studies of rFVIIa use was 0.17%. Specifically, the risk of thrombotic events was 0.11% for CHwI, 1.77% for AH, 0.82% for congenital factor VII deficiency and 0.19% for GT. Emerging non-factor therapies such as emicizumab have changed the treatment landscape of haemophilia A, including preventing bleeding in patients with CHwI. However, rFVIIa will continue to play a significant role in the treatment of such patients, particularly during breakthrough bleeding or surgical procedures.

High Rates of Anti-αIIbß3 Antibodies Produced by a Glanzmann Thrombasthenia Patient after First and Unique Red Blood Cells Administration.

Immunization against the platelet αIIbß3 glycoprotein due to blood transfusion represents one of the most severe complications in Glanzmann thrombasthenia (GT) disease. Anti-αIIbß3 isoantibodies development may lead to ineffective platelet transfusion and can, in case of pregnancy, cross the placenta leading to fetal thrombocytopenia. We describe here the case of a girl with type I GT who developed high rates of anti-αIIbß3 isoantibodies after first and unique blood transfusion. Surprisingly, this patient had only received red blood cell concentrates and immunization was presumably stimulated by the residual presence of platelets in concentrates. This study emphasizes the need for regular anti-αIIbß3 antibodies screening in GT, even though patients have never been previously transfused with platelet concentrates.

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.

A Novel Homozygous Frameshift Mutation in ITGB3 Causes Glanzmann's Thrombasthenia.

The objective of this study was to elucidate the molecular characteristics of a Chinese family with Glanzmann's thrombasthenia (GT). The proband was diagnosed with GT based on clinical manifestations, platelet aggregation, and the expression of CD41 and CD61 in platelets. Whole-exome and Sanger sequencing were used to detect genetic defects related to GT in the proband and the family of the pedigree. Whole-exome sequencing showed a c.1784-1802delinsGTCACA, p. S595Cfs*70 homozygous mutation in exon 11 of the ITGB3 gene in the proband. Heterozygous mutations were found in the proband's parents, grandmother, uncle, aunt, and younger brother. This novel p. S595Cfs*70 ITGB3 gene mutation is not present in the 1000 Genomes and ExAC databases.

New αIIbß3 variants in 28 Turkish Glanzmann patients; structural hypothesis for complex activation by residues variations in I-EGF domains.

Glanzmann thrombasthenia (GT) is a rare autosomal recessive bleeding disorder characterized by impaired platelet aggregation due to defects in integrin αIIbß3, a fibrinogen receptor. Platelet phenotypes and allelic variations in 28 Turkish GT patients are reported. Platelets αIIbß3 expression was evaluated by flow cytometry. Sequence analyzes of ITGA2B and ITGB3 genes allowed identifying nine variants. Non-sense variation effect on αIIbß3 expression was studied by using transfected cell lines. 3D molecular dynamics (MDs) simulations allowed characterizing structural alterations. Five new alleles were described. αIIb:p.Gly423Asp, p.Asp560Ala and p.Tyr784Cys substitutions impaired αIIbß3 expression. The αIIb:p.Gly128Val substitution allowed normal expression; however, the corresponding NM_000419.3:c.476G>T variation would create a cryptic donor splicing site altering mRNA processing. The ß3:p.Gly540Asp substitution allowed αIIbß3 expression in HEK-293 cells but induced its constitutive activation likely by impairing αIIb and ß3 legs interaction. The substitution alters the ß3 I-EGF-3 domain flexibility as shown by MDs simulations. GT variations are mostly unique although the NM_000419.3:c.1752 + 2 T > C and NM_000212.2:c.1697 G > A variations identified in 4 and 8 families, respectively, might be a current cause of GT in Turkey. MD simulations suggested how some subtle structural variations in the ß3 I-EGF domains might induce constitutive activation of αIIbß3 without altering the global domain structure.

Analysis of Integrin αIIb Subunit Dynamics Reveals Long-Range Effects of Missense Mutations on Calf Domains.

Integrin αIIbß3, a glycoprotein complex expressed at the platelet surface, is involved in platelet aggregation and contributes to primary haemostasis. Several integrin αIIbß3 polymorphisms prevent the aggregation that causes haemorrhagic syndromes, such as Glanzmann thrombasthenia (GT). Access to 3D structure allows understanding the structural effects of polymorphisms related to GT. In a previous analysis using Molecular Dynamics (MD) simulations of αIIbCalf-1 domain structure, it was observed that GT associated with single amino acid variation affects distant loops, but not the mutated position. In this study, experiments are extended to Calf-1, Thigh, and Calf-2 domains. Two loops in Calf-2 are unstructured and therefore are modelled expertly using biophysical restraints. Surprisingly, MD revealed the presence of rigid zones in these loops. Detailed analysis with structural alphabet, the Proteins Blocks (PBs), allowed observing local changes in highly flexible regions. The variant P741R located at C-terminal of Calf-1 revealed that the Calf-2 presence did not affect the results obtained with isolated Calf-1 domain. Simulations for Calf-1 + Calf-2, and Thigh + Calf-1 variant systems are designed to comprehend the impact of five single amino acid variations in these domains. Distant conformational changes are observed, thus highlighting the potential role of allostery in the structural basis of GT.

Utility of the ISTH bleeding assessment tool (BAT) in diagnosis of Glanzmann Thrombasthenia patients.

Objectives: To assess the utility of ISTH-BAT (International Society on Thrombosis and Hemostasis- Bleeding Assessment Tool) in the diagnosis of Glanzmann Thrombasthenia (GT) in comparison to controls. Methods: It was a case-control study carried out at The Children's Hospital, Lahore from January 2012 to May 2021. All patients from neonates to 18 years with a final diagnosis of GT were studied retrospectively. The clinical details were collected from hospital records and telephonically on ISTH-BAT questionnaire after taking informed consent. The same proforma was obtained from 75 healthy controls. Data was analyzed on SPSS version 26. Results: Out of 427 patients with suspected platelet function disorders, 133 were diagnosed as GT. The mean age was 7.29±5 years. Male to female ratio was 1.1:1. Among cases, 76.6% were products of consanguineous marriage. Epistaxis was the commonest symptom with highest score (p value<0.001). Cutaneous and oral cavity bleeds were more severe and frequent in patients than controls (p value < 0.004). The median ISTH-BAT score among patients was nine while in control group was one. Sensitivity was 86.4%, specificity was 77.3%, positive predictive value was 0.87 and negative predictive value was 0.76. Area under the receiver operator curve was 0.78 (95% confidence interval 0.82-0.90, p< 0.001*). Conclusion: ISTH-BAT scores were significantly higher in GT patients than controls. So, we recommend the inclusion of ISTH-BAT in diagnostic evaluation of patients with suspected Glanzmann Thrombasthenia.

Mutations in RASGRP2 gene identified in patients misdiagnosed as Glanzmann thrombasthenia patients.

INTRODUCTION: Glanzmann thrombasthenia (GT) is a severe inherited platelet function disorder (IPFD), presenting with bleeding diathesis and impaired platelet aggregation, is caused by mutations in the genes ITGA2B or ITGB3. AIM: We aimed to study the genetic cause of IPFD mimicking GT. METHODS: During 2017-2019, 16 patients were referred to our tertiary center with bleeding symptoms, impaired platelet aggregation and normal platelet count and size. RESULTS: Using flow cytometry, 13/16 patients were diagnosed with GT, yet three patients displayed normal surface expression of the integrins αIIbß3 and αvß3, as well as normal integrin αIIbß3 activation following incubation with the activating monoclonal antibody anti-LIBS6, while platelet activation following ADP or epinephrine was impaired. Whole exome sequencing detected 2 variants in RASGRP2 gene in all 3 patients. DISCUSSION: Both RASGRP2 mutations predicted frameshift, premature stop codon (p. I427Mfs*92 and p. R494Afs*54, respectively) and truncated calcium-sensing guanine nucleotide exchange factor [CalDAG-GEFI]- the major signaling molecule that regulates integrin-mediated aggregation and granule secretion, causing IPFD-18. CONCLUSION: Patients who suffer from bleeding diathesis without immune dysregulation, may be mistakenly diagnosed as GT. Further studies are required to confirm the diagnosis of specific IPFD.

Nonsense-mediated mRNA decay efficiency influences bleeding severity in ITGA2B c.2659C > T (p.Q887X) knock-in mice.

Glanzmann's thrombasthenia (GT) is a severe hemorrhagic disease. It is caused by mutations in ITGA2B or ITGB3, which are the respective genes encoding integrin αIIb and ß3. Despite widespread mutational analysis, the mechanisms underlying the extensive variability in bleeding severity observed among affected individuals remains poorly understood. In order to explore the mechanisms conferring for bleeding heterogeneity, three GT patients with ITGA2B c.2671C > T (p.Q891X) who possessed different bleeding scores were studied. Analysis showed that there was significant difference in nonsense-mediated mRNA decay (NMD) efficiency among the three patients. These differences positively correlated with their bleeding score. Next, a knock-in mouse model (KI mice) with the ITGA2B c.2659C > T (p.Q887X) was generated using CRISPR/Cas9. Importantly, this mutation is homologous to ITGA2B c.2671C > T (p.Q891X) in humans. The bleeding time of KI mice was significantly in comparison to the wide-type mice. Interestingly, bleeding was stopped after treatment with caffeine, which is a known NMD inhibitor. This suggests that NMD efficiency potentially influences bleeding severity in ITGA2B c.2659C > T (p.Q887X) KI mice.

Integrin ß3 Deficiency Results in Hypertriglyceridemia via Disrupting LPL (Lipoprotein Lipase) Secretion.

OBJECTIVE: Integrin ß3 is implicated in numerous biological processes such as its relevance to blood triglyceride, yet whether ß3 deficiency affects this metabolic process remains unknown. Approach and Results: We showed that the Chinese patients with ß3-deficient Glanzmann thrombasthenia had a 2-fold higher serum triglyceride level together with a lower serum LPL (lipoprotein lipase) level than those with an αIIb deficiency or healthy subjects. The ß3 knockout mice recapitulated these phenotypic features. The elevated plasma triglyceride level was due to impaired LPL-mediated triglyceride clearance caused by a disrupted LPL secretion. Further analysis revealed that ß3 directly bound LPL via a juxtamembrane TIH (threonine isoleucine histidine)720-722 motif in its cytoplasmic domain and functioned as an adaptor protein by interacting with LPL and PKD (protein kinase D) to form the PKD/ß3/LPL complex that is required for ß3-mediated LPL secretion. Furthermore, the impaired triglyceride clearance in ß3 knockout mice could be corrected by adeno-associated virus serotype 9 (AAV9)-mediated delivery of wild-type but not TIH720-722-mutated ß3 genes. CONCLUSIONS: This study reveals a hypertriglyceridemia in both ß3-deficient Chinese patients and mice and provides novel insights into the molecular mechanisms of the significant roles of ß3 in LPL secretion and triglyceride metabolism, drawing attention to the metabolic consequences in patients with ß3-deficient Glanzmann thrombasthenia.

Long-term treatment with thalidomide for severe recurrent hemorrhage from intestinal angiodysplasia in Glanzmann Thrombasthenia.

Gastrointestinal angiodysplasia (GIA) is the most common cause of occult gastrointestinal bleeding (GIB) requiring often hospitalization and transfusions, especially in patients with hemorrhagic disorders. Thalidomide, impairing neo-angiogenesis, has been successfully used in the management of bleeding in patients with GIA and in particular in patients with inherited bleeding disorders. Only one case of short-term treatment with thalidomide in a patient with Glanzmann thrombasthenia (GT) and recurrent GIB due to GIA has been reported so far.We report the case of a woman with GT developing high frequency recurrent GIB due to GIA requiring repeated blood and platelet transfusions, who was treated with thalidomide obtaining a striking and stable reduction of GIB and of the requirement of platelet and blood transfusions for over 5 years. Moreover, we raise the suspicion that the association between GT and GIA may not be fortuitous.

Identification of three novel pathogenic ITGA2B and one novel pathogenic ITGB3 mutations in patients with hereditary Glanzmann's thrombasthenia living in Eastern Turkey.

Glanzmann's thrombasthenia (GT) is an autosomal recessive disorder in which the underlying problem is the lack or dysfunction of the GpIIb/IIIa receptor on the platelet surface. The present study determines the genetic mutation typology and analyzes the association between mutation types and clinical findings in patients diagnosed with GT who were followed up in Department of Pediatric Hematology of the Yüzüncü Yil University School of Medicine. The medical charts of 17 patients who underwent therapy and that were followed up in the Department of Pediatric Hematology of the Yüzüncü Yil University Dursun Odabas Medical Center between January 2008 and April 2018 were reviewed retrospectively. Data on such patient characteristics as present genetic mutations, age, gender, age at diagnosis, presenting symptoms, clinical findings, and platelet count and volume were garnered from the patient records. Of the 12 patients identified with genetic mutations, six had the same type of mutation, while four were identified with novel mutations that have to date not been defined in literature. Of these four mutations, three were located in the ITGA2B gene and one in the ITGB3 gene. The present study identified no significant association between the genetic and clinical findings of the patients. Novel mutations were identified in four cases in the present study. No association was found between the mutation type, and the bleeding scores and bleeding phenotypes of the patients. Further studies involving a larger number of patients are required to determine the relationship between the genotypes and clinical findings in patients with GT.

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.

Menstrual and obstetrical bleeding in women with inherited platelet receptor defects-A systematic review.

INTRODUCTION: Women with inherited platelet receptor defects (IPRD) may have an increased risk of heavy menstrual bleeding (HMB) and postpartum haemorrhage (PPH). AIM: To present a systematic overview of the literature on the prevalence and management of menstrual and obstetrical bleeding in women with IPRD. METHODS: Electronic databases were searched for original patient data on the prevalence and management of HMB and PPH in women with known IPRD or who were being investigated for IPRD. RESULTS: Sixty-nine papers (61 case reports/series and 8 cohort studies) were included. Overall, studies were rated as 'poor quality'. The included cohort studies reported HMB in 25% (13/52) of women with Bernard-Soulier syndrome and in 22.1% (34/154) of women with Glanzmann thrombasthenia. In total, 164 deliveries in women with IPRD were described. Excessive bleeding occurred in 16.9% (11/65) of deliveries described in the largest cohort. PPH occurred in 63.2% (55/87) of deliveries described in case reports/series. PPH occurred in 73.7% (14/19) of deliveries that were not covered by prophylaxis compared with 54.2% (32/59) of deliveries that were (OR = 2.36, 95% CI 0.75-7.40). Neonatal bleeding complications were reported in 10.0% (8/80) of deliveries. In all (6/6) deliveries with neonatal bleeding complications wherein the presence of alloantibodies was investigated, either antiplatelet or anti-HLA antibodies were detected. DISCUSSION/CONCLUSION: Menstrual and particularly obstetrical bleeding problems frequently occur in women with IPRD, based on small case reports and series of poor quality. International collaboration, preferably on prospective studies, is needed to improve clinical management of women-specific bleeding in IPRD.