ISTH Bleeding Assessment Tool Research Articles

ISTH bleeding assessment tool and platelet function analyzer in children with mild inherited platelet function disorders.

To evaluate the diagnostic performance of platelet function analyzer (PFA) and The International Society on Thrombosis and Hemostasis bleeding-assessment-tool (ISTH-BAT) in detecting mild inherited platelet function disorders (IPFDs) in children with suspected bleeding disorders. Prospective single-center diagnostic study including consecutive patients <18 years with suspected bleeding disorder and performing a standardized workup for platelet function defects including ISTH-BAT, PFA, platelet aggregation testing, blood smear-based immunofluorescence, and next-generation sequencing-based genetic screening for IPFDs. We studied 97 patients, of which 34 von Willebrand disease (VWD, 22 type-1, 11 type-2), 29 IPFDs (including delta-/alpha-storage pool disease, Glanzmann thrombasthenia, Hermansky-Pudlak syndrome) and 34 with no diagnosis. In a model combining PFA-adenosine diphosphate (ADP), PFA-epinephrine (EPI), and ISTH-BAT overall performance to diagnose IPFDs was low with area under the curves of 0.56 (95% CI 0.44, 0.69) compared with 0.84 (95% CI 0.76, 0.92) for VWD. Correlation of PFA-EPI/-ADP and ISTH-BAT was low with 0.25/0.39 Spearman's correlation coefficients. PFA were significantly prolonged in patients with VWD and Glanzmann thrombasthenia. ISTH-BAT-scores were only positive in severe bleeding disorders, but not in children with mild IPFDs or VWD. Neither ISTH-BAT nor PFA or the combination of both help diagnosing mild IPFDs in children. PFA is suited to exclude severe IPFDs or VWD and is in this regard superior to ISTH-BAT in children.

Diagnostic value of clot formation parameters determined by rotational thromboelastometry in 63 patients with congenital dysfibrinogenemia.

Rotational thromboelastometry (ROTEM) is a global hemostasis assay. The diagnosis added value of ROTEM in congenital dysfibrinogenemia remains to be established. The aim of this study was to analyze clot formation by ROTEM in a cohort of dysfibrinogenemic patients and to establish correlations with genotype, clinical features, and coagulation parameters. The study included genetically confirmed congenital dysfibrinogenemia cases (n = 63) and healthy controls ( n = 50). EXTEM, INTEM, FIBTEM tests were used to measure ROTEM parameters, that is, clotting time (CT), clot formation time (CFT), maximal clot firmness (MCF) and amplitude 10 min after CT (A10). The ISTH bleeding assessment tool was used to determine bleeding episodes. CT (INTEM) was statistically significantly shorter in congenital dysfibrinogenemia patients compared to controls while CFT (EXTEM) was prolonged. Patients's MCF in EXTEM, INTEM, and FIBTEM were similar to controls while A10 (FIBTEM) was statistically significantly lower. Fibrinogen activity was positively correlated with fibrinogen antigen, A10 and MCF in all three assays. Bleeding phenotypes were observed in 23 (36.5%) patients. Only CFT in EXTEM and CT in INTEM were statistically different in patients with bleeding phenotype versus controls. Carriers of the FGA mutation p.Arg35His had a CT (EXTEM) slightly prolonged and a reduced A10 (FIBTEM) compared to controls. Some ROTEM parameters were able to distinguish congenital dysfibrinogenemia patients from controls, and patients with a bleeding phenotype. Prolonged CFT in EXTEM were associated with congenital dysfibrinogenemia and bleeding phenotype. Bleeding episodes in most patients were generally mild and prevalence of thrombosis was very low.

Multicenter Study of Diagnostic Tool for Patients with Hemophilia: From Bedside to Comprehensive Investigations.

Hemophilia cannot be diagnosed in most laboratories of economically less-developed countries leading to high mortality and morbidity rates. A diagnostic tool was established ranging from bleeding assessment and a simple bedside test of mixing venous clotting time (VCT) to comprehensive DNA analysis for patients with hemophilia. Patients with known (n=80) and suspected hemophilia (n=14) were included. Their bleeding symptoms were initially evaluated using verified translated-Thai ISTH bleeding assessment tool. Then, blood samples were drawn using a two-syringe technique, 2 mL each was placed in three tubes, for the mixing VCT and citrate blood was kept for coagulogram and coagulation factor assay. Finally, DNA analysis was determined. A total of 94 patients with hemophilia (A68, B26) defined as severe (A 57, B 17), moderate (A 7, B 5), and mild degrees (A 4, B 4) with the mean (SD) age of 14.0 (11.7) years and 24 normal controls aged 25.5 (4.5), were enrolled in the study. The mean (SD) bleeding score of patients with hemophilia was 13.5 (5.5), which did not significantly differ between patients with hemophilia A and B. The mixing venous clotting time offered the presumptive diagnosis of hemophilia A and B, which were subsequently confirmed by the prolonged APTT, low FVIII:C and FIX:C and mutations on the factor VIII and IX genes. A diagnostic tool for bleeding assessment, mixing venous clotting time, coagulogram, coagulation factor assay, and DNA analysis for patients with hemophilia has been established in the existing health-care system.

Multimodality Platelet Evaluation By Mass Cytometry and Genetic Analysis in Patients with Bleeding Disorders

Introduction: Bleeding disorders are a diverse group of conditions characterized by abnormal bleeding tendencies. Platelet dysfunction is a common underlying cause and although traditional platelet aggregometry is important in the clinical work-up, platelet functional assays often provide limited diagnostic insights, prompting the need for more advanced techniques and approaches. This study aims to explore the utility of mass cytometry combined with genetic analysis in assessing platelet function in patients with otherwise unspecified bleeding tendencies. Methods: In a single-center prospective study, enrolled patients with clinical and laboratory suspicion of platelet-related bleeding disorders were subjected to multimodality evaluation. Mass cytometry (CyTOF) allows for simultaneous evaluation of multiple platelet markers on single cells, including those involved in platelet activation, aggregation, and adhesion, through a panel of heavy metal-conjugated antibodies. Whole genome sequencing with targeted analysis was utilized to identify potential genetic variants associated with quantitative and qualitative platelet disorders and correlated with CyTOF findings. Results: CyTOF revealed altered platelet markers associated with activation, aggregation, and adhesion in 40% (n=14) of total participants (n=35) with suspected platelet-related bleeding disorders ( Table 1). CyTOF showed significant concordance with platelet aggregometry in 74% of participants (data not shown). Alterations in specific CyTOF markers (e.g., PAC-1, CD40L) correlated with bleeding risk by univariate analysis of patients stratified to high vs low risk groups based on ISTH bleeding assessment tool (ISTH-BAT) ( Table 1). Multivariate analysis using a random forest machine learning algorithm identified variables most predictive of bleeding risk, including CD40L, PAC-1, P-selectin, and mean platelet volume. Genetic analysis identified one or more variants in genes implicated in qualitative and quantitative platelet disorders in 61% (n=19) of total patients analyzed ( Figure 1). Abnormal CyTOF findings were associated with greater proportion of variants detected (79% with abnormal CyTOF vs 53% with normal CyTOF) ( Figure 1). Direct associations between specific mass cytometry findings and genetic variants (i.e., GPIIb, GPIIIa, GPIb, GPIX, etc.) were discovered for several patients, providing important information in evaluating variant pathogenicity and diagnostic validation. Conclusion: This study highlights the potential of integrating mass cytometry and genetic analysis to assist in the diagnosis of otherwise unspecified bleeding tendencies, bleeding risk stratification, and patient management. Our findings enhance the understanding of platelet function in patients with bleeding disorders and provide valuable insights into the complex relationship between platelet phenotypes and genetic determinants. Further investigations with a larger patient cohort are warranted to validate and expand upon these initial correlations and explore their clinical implications in diagnosis and management of bleeding disorders.

Prothrombin consumption as an indicator of hemorrhagic phenotype in mild platelet function disorders.

The bleeding risk of patients with mild platelet function disorders is difficult to assess and their phenotype remains ill-explored. This study was designed to establish a comprehensive biological phenotype of patients with mild platelet function disorders. Twenty patients were included with persistent abnormal light transmission aggregometry (LTA). The ISTH bleeding assessment tool (ISTH-BAT) was assessed to identify laboratory analyses associated with an abnormal hemorrhagic score. The majority of patients had defects that might affect Gαi protein signaling pathways or minor abnormalities. No LTA nor flow cytometry parameters were associated with an above-normal hemorrhagic score. However, prothrombin consumption, which corresponds to the ratio of serum residual factor II to plasma residual factor II, was significantly higher (p = .006) in the abnormal ISTH-BAT group (mean = 14%, SD = 6) compared with the normal ISTH-BAT group (mean = 8%, SD 4). Prothrombin consumption was significantly associated with ISTH-BAT score (r = .5287, IC 95% 0.0986-0.7924, p = .0165). In this group of patients, there was an association between a pathological bleeding score and increased prothrombin consumption. This test could be used as an additional indicator of platelet function abnormality liable to be related to bleeding risk.

Bleeding disorder of unknown cause: Results from Iranian study

BackgroundDefinite diagnosis of patients with mild to moderate bleeding is challenging. Some studies reported that even more than 50% of their patients remained undiagnosed which is classified as a Bleeding disorder of unknown cause (BDUC). This study aims to document the clinical characteristics and proportion of patients with BDUC in the Iranian Comprehensive Hemophilia Care Center (ICHCC) one of the referral centers for diagnosis of congenital bleeding disorder in Iran. MethodsThis study was conducted on 397 patients who were referred with a bleeding manifestation to ICHCC from 2019 to 2022. Demographic and laboratory data were documented for all patients. Bleeding questionnaires including ISTH-Bleeding Assessment tool (ISTH-BAT) and the Molecular and Clinical Markers for the Diagnosis and Management of Type 1 (MCMDM-1 (ISTH-BAT, MCMDM-1, and the Pictorial Bleeding Assessment Chart (PBLAC) were filled out for all patients. The data were analyzed by the statistical package for social science (SPSS version 22, SPSS, Chicago, Illinois, USA). ResultsBDUC was diagnosed in 200 patients and 197 patients reached the final diagnosis. Hemophilia, von Willebrand disease (VWD), factor (F) VII deficiency, and platelet functional disorders (PFDs) were confirmed in 54, 49, 34, and 15 of the patients, respectively. No significant difference was found in bleeding scores between patients with BDUC and those with confirmed disease. In contrast, after setting cut-off (ISTH-BAT for males ≥ 4 and females ≥ 6 and MCMDM-1 for males ≥ 3 and females ≥ 5) clinically significant difference was found. There was no association between having a positive consanguineous marriage and setting a diagnosis; however, significant associations were seen for having a positive family history of bleeding. Age (OR =0.977, 95% CI.965–0.989), gender (BDUC female, 151/200; final diagnosis female, 95/197) (OR=3.3, 95% CI 2.16–5.06), family history (OR = 3.19, 95% CI 1.99–5.11), and consanguineous marriage (OR=1.59, 95% CI 1.03–2.45) were considered as a risk factor for categorizing the patients with BDUC or final diagnosis. ConclusionThe findings are mainly in line with previous studies about BDUC patients. The large number of patients with BDUC underlines the incompleteness of available routine laboratory tests and shows the necessity of progress in the development of reliable diagnostic tools to identify underlying bleeding disorders.

Bleeding Phenotype Does Not Appear to Correlate with Factor VIII Levels or Genetic Mutation in an Exclusive Pediatric Cohort of Hemophilia a Carriers

Introduction: Inherited Hemophilia A is defined as Factor VIII (FVIII) deficiency, with levels <0.40 IU/ml. Female carriers exhibit varying degrees of X chromosome inactivation, with resultant variable FVIII activity levels. Bleeding phenotype in Hemophilia A carriers has been thought to be due to low FVIII levels; however, adult studies have shown lack of correlation of FVIII levels and bleeding phenotype in some patients. Our study aimed to correlate FVIII levels with bleeding phenotype and genetic mutations in pediatric hemophilia A carriers. Methods: Retrospective medical record review of Hemophilia A carriers <18 years of age was undertaken at our center. Inclusion criteria were family history of Hemophilia A and FVIII mutation or FVIII level <0.40 IU/ml in patients without genetic testing done. Patients with other co-existing bleeding disorders were excluded. Statistical analysis was done by Chi Square/Exact tests. Results: Twenty-three pediatric Hemophilia A carriers were eligible, with median age of 12 years (range1-16). Fifteen were adolescents >10 years. Fourteen (60.9%) had FVIII level >0.40 IU/ml with 8 (57.1%) categorized as asymptomatic, and 6 (42.9%) symptomatic carriers in accordance with the new ISTH nomenclature. Nine (39.1%) patients had FVIII <0.40 IU/ml, with 8 (88.8%) categorized as mild (FVIII 0.05-0.40 IU/ml), 1 (11.1%) as moderate (FVIII 0.01-0.05 IU/ml), and none as severe (<0.01 IU/ml) Hemophilia A, as per the new nomenclature. Bleeding Scores (BS) were obtained in all patients using the ISTH Bleeding Assessment Tool (ISTH-BAT) with a median BS of 1 (range 0-7). A significant BS of >2 was present in 4/9 (44.4%) patients with FVIII <0.40 IU/ml, and 4/14 (28.6%) with FVIII >0.40 IU/ml, the difference was not statistically significant (p=0.40) (Table 1). Two symptomatic carriers with FVIII >0.4 IU/ml, had BS of 1 and 2. 5/15 adolescents (33.3%) had BS>2 (BS of 4 in 3; BS of 7 in 2). FVIII was measured with one stage assay (OSA) (N=17; 73.9%), chromogenic substrate assay (CSA) (N= 2; 8.7%) or both (N=4; 17.4%), with 1 patient's (4.3%) CSA discrepantly lower than OSA by 0.62 IU/ml and none with inverse discrepancy. Genetic testing was done in 20/23 (86.9%) patients, with FVIII missense mutations in 14 (70%), intron inversions in 4 (20%), and deletions in 2 (10%), their association with BS did not show statistically significant difference (p=0.6) (Table 2). Conclusion: Our study was done exclusively in pediatric Hemophilia A carriers, as it is important to identify children at risk of bleeding and institute preventive measures early. Unlike in adult women, higher number (one-third) of our patients experienced mucosal bleeding, and none reported joint or muscle bleeding. Our study showed lack of statistically significant association of FVIII levels with bleeding phenotype. According to the new ISTH nomenclature, 39.1% of our study patients have the diagnosis of Hemophilia A, of whom 55.6% did not have a significant BS. Of the 60.9% categorized as carriers, 28.6% had a significant BS. In addition, we found lack of statistically significant correlation of genetic mutation type with the bleeding phenotype, with none, 5% and 25% of the patients with deletion, intron inversion and missense mutation having a significant BS respectively. Follow-up/BS reassessment in our cohort is planned to monitor BS increase with age. Our study limitations include small cohort and retrospective analysis. Future pediatric studies are required to identify coagulation/genetic parameters that correlate better with bleeding phenotype, which may then help with early recognition and prompt institution of preventive therapy to pediatric Hemophilia A carriers at risk of bleeding, in order to avoid bleeding complications during adulthood. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Type 2M VWD Laboratory Defects More Consistent Than Bleeding Symptoms across Family Members

Background Von Willebrand disease (VWD) is an inherited bleeding disorder characterized by a defect or decrease of von Willebrand factor (VWF). Type 2 VWD results from qualitative defects in VWF. Type 2M VWD is defined by defective platelet binding to GPIb and/or collagen. While the inheritance of type 2M VWD is autosomal dominant, the extent of symptoms across family members has not been well characterized. Methods Subjects included index cases with type 2M VWD and all enrolled family members from a large US study of VWD (Zimmerman Program). Index cases were enrolled due to a prior diagnosis of VWD. All available family members were enrolled if willing. VWF testing performed included VWF antigen (VWF:Ag), VWF platelet binding by either VWF ristocetin cofactor activity (VWF:RCo) or VWF:GPIbM, collagen binding with types I, III or IV collagen (VWF:CB1, VWF:CB3, VWF:CB4) and VWF multimer distribution. Bleeding scores were calculated using the ISTH bleeding assessment tool (BAT). DNA sequencing was performed for the full length VWF gene. Statistics were calculated using GraphPad Prism with a p value of <0.05 considered significant. Family members were defined as affected if they had VWF activity levels consistent with type 2M VWD and presence of genetic variant if identified. Results 24 index cases, 51 affected family members and 40 unaffected family members were available for analysis. The mean VWF:RCo/VWF:Ag ratio for index cases was 0.5 and the mean VWF:CB/VWF:Ag ratio was 1.05. The VWF:RCo/VWF:Ag ratio was similar in affected family members (0.44, p=NS) but higher as expected in unaffected members (0.89, p<0.001 for index case vs. unaffected, p<0.001 for affected vs. unaffected). In contrast, there was no difference in VWF:CB/VWF:Ag ratios between index cases and affected family members (0.94, p=NS). Data for VWF:GPIbM, collagens I and IV were available only on index cases, and showed low VWF:GPIbM/VWF:Ag (mean 0.79), higher VWF:CBI/VWF:Ag (mean 1.31) and lower VWF:CBIV/VWF:Ag (mean 0.85). There was a negative correlation between VWF:GPIbM and VWF:CBIV, with subjects having either low VWF:GPIbM and normal VWF:CBIV or low VWF:CBIV and normal VWF:GPIbM. Similar results were seen for VWF:CB1 although only 1 subject was diagnosed with type 2M VWD and low VWF:CB1. Median bleeding scores were highest in index cases (7.5), intermediate in affected family members (3) and normal in unaffected family members (1). There was a significant difference between index cases and affected family members (<0.015), and between index cases and unaffected family members (p<0.001). One subject had a genetic variant in the VWF A3 domain, one in the VWF D3 domain and the remainder of index cases had a defect in the VWF A1 domain. Conclusions These findings suggest that decreases in platelet and collagen binding activity increase bleeding risk in families with type 2M VWD. Index cases had higher bleeding scores as compared to affected family members, suggesting that diagnosis of family members may require more attention. Precise understanding of these defects may assist in better diagnosis and treatment of von Willebrand disease.

Platelet function testing: Current practice among clinical centres in Northern Europe.

IntroductionPlatelet function tests are used to screen and diagnose patients with possible inherited platelet function defects (IPFD). Some acquired platelet dysfunction may be caused by certain drugs or comorbidities, which need to be excluded before testing.AimsTo identify current practice among centres performing platelet function tests in Northern Europe.MethodsA total of 14 clinical centres from Sweden (six), Finland (two), Denmark (two), Norway (one), Estonia (two) and Iceland (one) completed the survey questionnaire, the population capture area of about 29.5 million.ResultsSix of the 14 (42.8%) centres providing platelet function assessment represent comprehensive treatment centres (EUHANET status). A Bleeding score (BS) or ISTH bleeding assessment tool (ISTH BAT score) is evaluated in 11/14 (78.6%) centres and family history in all. Five/14 centres (35.7%) use structured preanalytical patient instructions, and 10/14 (71.4%) recorded questionnaire on the preassessment of avoidance of any drugs or natural products affecting platelet functions. Preliminary investigations of screening tests of coagulation are performed in 10/14 (71.4%), while in 4/14 (28.6%), the diagnostic work‐up of IPFD and von Willebrand disease (VWD) is performed simultaneously. The work‐up of IPFD includes peripheral blood smear in 10/14 (71.4%), platelet aggregometry in all, flow cytometry in 10/14 (71.4%) and Platelet Function Analysis (PFA) in 3/11 (28.6%). Molecular genetic diagnosis is available in 7/14 (50%) centres.ConclusionsThe considerable variability in the current practice illustrates the need for harmonization between the Northern European centres according to the international registers (i.e. EUHASS) and IPFD guidelines (ISTH, EHA).

Low COAT platelets are frequent in patients with bleeding disorders of unknown cause (BDUC) and can be enhanced by DDAVP

Low COAT platelets are frequent in patients with bleeding disorders of unknown cause (BDUC) and can be enhanced by DDAVP

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.

Levels of procoagulant microparticles expressing phosphatidylserine contribute to bleeding phenotype in patients with inherited thrombocytopenia.

Inherited thrombocytopenia is a heterogeneous group of hereditary disorders with varying bleeding tendencies, not simply related to platelet count. Platelets transform into different subpopulations upon stimulation, including procoagulant platelets and platelet microparticles (PMPs), which are considered critical for haemostasis. We aimed to investigate whether abnormalities in PMP and procoagulant platelet function were associated with the bleeding phenotype of inherited thrombocytopenia patients. We enrolled 53 inherited thrombocytopenia patients. High-throughput sequencing of 36 inherited thrombocytopenia related genes was performed in all patients and enabled a molecular diagnosis in 57%. Bleeding phenotype was evaluated using the ISTH bleeding assessment tool, dividing patients into bleeding (n = 27) vs. nonbleeding (n = 26). Unstimulated and ADP, TRAP or collagen-stimulated PMP and procoagulant platelet functions were analysed by flow cytometry using antibodies against granulophysin (CD63), P-selectin (CD62P), activated GPIIb/IIIa (PAC-1) and a marker for phosphatidylserine expression (lactadherin). Procoagulant platelets were measured in response to collagen stimulation. An in-house healthy reference level was available. Overall, higher levels of activated platelets, PMPs and procoagulant platelets were found in nonbleeding patients compared with the reference level. Nonbleeding patients had higher proportions of phosphatidylserine and PMPs compared with bleeding patients and the reference level, in response to different stimulations. Interestingly, this finding of high proportions of phosphatidylserine and PMPs was limited to PMPs, and not present in procoagulant platelets or platelets. Our findings indicate that nonbleeding inherited thrombocytopenia patients have compensatory mechanisms for improved platelet subpopulation activation and function, and that generation of phosphatidylserine expressing PMPs could be a factor determining bleeding phenotype in inherited thrombocytopenia.

Clinical and molecular characterization of Iranian patients with congenital fibrinogen disorders

IntroductionCongenital fibrinogen disorders (CFDs) are caused by mutations in the FGA, FGB and FGG genes and are classified as quantitative and qualitative fibrinogen defects. This study sought to determine the genetic background of CFDs in Iran and to examine the genotype-phenotype correlation. MethodsFourteen patients with a CFD diagnosis were included. Fibrinogen antigen and activity were measured by the immunoturbidimetric and Clauss methods respectively. Gene sequencing was performed following a polymerase chain reaction amplification of fibrinogen’s genes. The ISTH Bleeding Assessment Tool was also evaluated for all cases. ResultsPatients were diagnosed with dysfibrinogenemia (n = 10), hypodysfibrinogenemia (n = 2) and afibrinogenemia (n = 2). Seven different mutations located on FGA exon 2 (57 %), exon 4 (7%), exon 5 (7%) and FGG exon 8 (29 %) were identified. In patients with qualitative deficiencies, mutations were including p.Arg38Thr, p.Arg35His, p.Arg35Cys, p.Val145Asp, and p.Arg301Cys and were including p.Gly316GlufsX105 and p.Trp52stop in afibrinogenemic patients. In dysfibrinogenemia, two hotspot mutations, FGA Arg35 and FGG Arg301 were identified in 60 % of patients and the remaining (40 %) had p.Arg38Thr mutation. The p.Val145Asp and two hotspot mutations, p.Arg35His, p.Arg35Cys, were identified for the first time in Iran. The overall median (range) bleeding score (BS) was 4 (0-6) in all patients and it was 3.5 (0–5) in dysfibrinogenemia. Cutaneous bleeding and menorrhagia were the most common bleeding manifestations. ConclusionThere was a weak genotype-phenotype correlation in CFDs and patients with dysfibrinogenemia were more symptomatic than in previous studies. Despite ethnic’s differences, the prevalence of hotspot mutations in dysfibrinogenemia was similar to the other studies.

Epidural/spinal anesthesia during delivery in women with factor XI deficiency, a single center experience.

The safety of neuro-axial anaesthesia (epidural/spinal) at labour of women with partial factor XI (FXI) deficiency is uncertain. Although FXI deficiency is frequent in Ashkenazi Jews, it is not routinely measured before labour. Our institute serves a large Ashkenazi population. We assumed that 10% of them have undiagnosed FXI deficiency. Assess the incidence, bleeding tendency and coagulation status among Jewish Ashkenazi women with FXI deficiency that underwent neuro-axial anaesthesia at delivery. Jewish Ashkenazi women who underwent neuro-axial anaesthesia at labour completed the SSC ISTH bleeding assessment tool (BAT) and had blood drawn for coagulation tests, FXI and thrombin generation after labour. Estimation for 10years was calculated from the 1-year sample. We recruited 261 women during 12months. Among them, 39 (15%) had FXI deficiency (<70%) with median FXI levels of 63% (range: 33%-70%). Around 50% of them underwent amniocentesis in the current pregnancy and prior neuro-axial anaesthesia with no bleeding complications. BAT score and thrombin generation did not differ between women regardless of FXI status. aPTT was longer in women with partial FXI deficiency (median - 28.6 sec vs 26.3 sec, P < .001, Table 2), although within the normal range in all women. No bleeding complications after neuro-axial anaesthesia at delivery were reported in our centre in the last decade though, and according to our estimation, at least 2150 women had partial FXI deficiency. A significant number of Jewish Ashkenazi women with undiagnosed partial FXI deficiency undergo neuro-axial anaesthesia at labour without bleeding complications.

Congenital platelet disorders and health status–related quality of life

BackgroundPatients with congenital blood platelet disorders (CPDs) demonstrate a predominantly mucocutaneous bleeding tendency. Repeated bleeds throughout life can have a significant impact on health status–related quality of life (HR‐QoL), but few studies have investigated HR‐QoL in patients with CPDs. ObjectivesTo determine HR‐QoL in patients with suspected or confirmed CPDs as compared with the general Dutch population and to assess the association between bleeding phenotype and HR‐QoL. MethodsData were derived from the Thrombocytopathy in the Netherlands (TiN) study, a cross‐sectional study of individuals suspected for a congenital platelet defect. TiN patients with an increased ISTH Bleeding Assessment Tool (ISTH‐BAT) score (>3 in men and > 5 in women) were included for analysis. HR‐QoL was assessed with the Short Form (SF)‐36 survey. Bleeding symptoms were evaluated with the ISTH‐BAT, resulting in a bleeding score. ResultsOne hundred fifty‐six patients were analyzed, of whom 126 (81%) were women. Sixty‐two patients (40%) had a confirmed CPD. Compared to the general Dutch population, patients with a suspected or confirmed CPD reported decreased physical functioning, limitations in daily activities due to physical health problems, limitations in social activities, decreased energy levels and fatigue, pain, and lower general health status. HR‐QoL was not correlated with the ISTH‐BAT score and was similar in patients with a confirmed CPD and those in whom a CPD could not be diagnosed. ConclusionA bleeding tendency in patients with a suspected or confirmed CPD significantly impacts HR‐QoL, independent of a confirmed explanatory diagnosis.

Clinico-hematological and thromboelastographic profiles in glanzmann's thrombasthenia.

: Glanzmann's thrombasthenia is a rare inherited bleeding disorder characterized by the quantitative or qualitative defect of glycoprotein IIb/IIIa receptor on platelets which leads to ineffective aggregation. Light transmittance aggregometry is considered as the gold standard for diagnosis of Glanzmann's thrombasthenia. Thromboelastography (TEG) is a global hemostatic assay which measures clot formation, clot strengthening and fibrinolysis. This study evaluates the clinical, laboratory and TEG profiles in patients with Glanzmann's thrombasthenia. Bleeding score by (International Society on Thrombosis and Haemostasis) ISTH-bleeding assessment tool (bleeding score), laboratory tests to diagnose Glanzmann's thrombasthenia, and TEG parameters were correlated in 11 Glanzmann's thrombasthenia patients. Seventeen participants with normal bleeding score were included as controls. Bleeding score was increased in all patients. The highest bleeding score was in an adult female (26), whereas the lowest score (4) was in two children of less than 1 year. Majority of TEG parameters (except R-time) showed a statistically significant difference between Glanzmann's thrombasthenia patients and controls (K-time: P < 0.001, angle: P < 0.001, maximum amplitude: P < 0.001). The average time required to record the maximum amplitude was 23 min. Maximum amplitude was markedly reduced in all Glanzmann's thrombasthenia patients with an average of 20.9 mm (reference range 44-68 mm) having 100% sensitivity. The thromboelastographic profile of Glanzmann's thrombasthenia showed a consistently reduced maximum amplitude. Hence reduced maximum amplitude with a normal platelet count, significant bleeding score and prolonged bleeding time could potentially be used as a preliminary algorithm for the diagnosis of Glanzmann's thrombasthenia.

Reliability and Feasibility of the Self-Administered ISTH-Bleeding Assessment Tool.

Introduction Standardized bleeding assessment tools (BATs), such as the International Society for Thrombosis and Hemostasis (ISTH)-BAT, are screening instruments used during the diagnostic workup of suspected bleeding disorders. A self-administered ISTH-BAT (self-BAT) would enhance screening and save time during an outpatient clinic visit. Aim This study was aimed to investigate the reliability and feasibility of the self-BAT. Methods The electronic self-BAT was created from the ISTH-BAT and paper-version of self-BAT and optimized by patients and physicians. Patients with a (suspected) congenital platelet defect (CPD), who had previously undergone physician-administered ISTH-BAT assessment, were invited to complete the self-BAT. Optimal self-BAT cut-off values to detect a bleeding tendency, as defined by the ISTH-BAT, were evaluated by receiver operator characteristic (ROC) curve analysis to reach a sensitivity ≥95%. Reliability was tested by assessing sensitivity, specificity, and intraclass correlation (ICC). Feasibility was evaluated on comprehension and length of self-BAT. Results Both versions of the BAT were completed by 156 patients. Optimal cut-off values for self-BAT to define a bleeding tendency were found to be identical to those of the ISTH-BAT. Normal/abnormal scores of the ISTH-BAT and self-BAT were agreed in 88.5% (138/156, 95% confidence interval [CI]: 0.83–0.93) of patients. The sensitivity and specificity of the self-BAT to detect a bleeding tendency were 96.9 and 48.1%, respectively. The ICC was 0.73. Self-BAT questions were graded by 96.8% (151/156) as “very easy,” “easy,” and “satisfactory” and questionnaire length as “exactly right” by 91% (142/156) of patients. Conclusion In patients with a (suspected) CPD, the self-BAT is sufficiently reliable and feasible to detect a bleeding tendency, which supports its use as a screening tool.

Correlation of bleeding score with frequency and severity of bleeding symptoms in FXIII deficiency assessing by the ISTH Bleeding Assessment Tool

ObjectivesThe ISTH bleeding assessment tool (ISTH-BAT) is developed for standardization of bleeding symptoms in bleeding disorders. The aim of this study is to apply this bleeding score for FXIII deficient patients and its relation to the frequency and severity of symptoms. MethodsIn this cross-sectional study, 63 patients with severe FXIII deficiency were evaluated for the assessment of bleeding score according to the standard ISTH-BAT questionnaire. All patients were registered at two major thrombosis and hemostasis centers in Iran affiliated to Zahedan University of medical sciences (50 patients) and Shiraz University of medical sciences (13 patients). ResultsSignificant correlations between the bleeding score and number of symptoms (r = 0.668, P < 0.001) and with a number of severe symptoms (r = 0.938, P < 0.001) were detected. There was no significant relationship between the mean bleeding score and CNS bleeding (P = 0.390). ConclusionThe ISTH-BAT score is an acceptable bleeding assessment tool for standardization and evaluation of patients with FXIII deficiency.

Diagnostic utility of the ISTH bleeding assessment tool in patients with suspected platelet function disorders

Unlabelled Box BackgroundBleeding assessment tools (BATs) have been widely implemented in the evaluation of patients with suspected bleeding disorders. However, diagnostic BAT utility regarding platelet function disorders is still elusive. AimWe aimed to assess the diagnostic value of the International Society on Thrombosis and Haemostasis BAT (ISTH‐BAT) for platelet function disorders in clinical practice. MethodsThe clinical characteristics and laboratory data of all consecutive patients with a suspected bleeding disorder referred between January 2012 and March 2017 to an outpatient unit of a university hospital were prospectively collected. The diagnostic evaluation was performed according to current recommendations following a prespecified protocol and platelet function was tested using light transmission aggregometry as well as flow cytometry. ResultsFive hundred and fifty‐five patients were assessed; 66.9% were female, median age was 43.7 years (interquartile range [IQR] 29.3, 61.7). Confirmed platelet function disorder was diagnosed in 54 patients (9.7%), possible platelet function disorder in 64 patients (11.5%), and other disorders in 170 patients (30.6%). Median scoring of the ISTH‐BAT was 2 in patients without a bleeding disorder (IQR 1, 3), 4 in patients with a possible platelet function disorder (2, 7), and 7 in patients with confirmed platelet function disorder (5, 9). Area under the receiver operating characteristic curve (the area under the curve [AUC]) was 0.75 (95% CI 0.70, 0.80). ConclusionsPresence of a platelet function disorder was associated with substantially higher BAT scorings compared to patients without. Our data suggest that the ISTH‐BAT provides a useful screening tool for patients with suspected platelet function disorders.

PS1475 COATED PLATELET FUNCTION IS RELATED TO BLEEDING PHENOTYPE IN PATIENTS WITH INHERITED THROMBOCYTOPENIA

Background:Platelets transform into different subpopulations following stimulation. Coated‐platelets (CPs) are a subpopulation of highly procoagulant platelets with an outer membrane coating of procoagulant proteins. Also, platelet microparticles (PMPs) released from the platelet membrane have procoagulant properties. Though CPs and PMPs are inferred critical for hemostasis, they have mainly been investigated in thrombotic and inflammatory diseases. Only few studies have investigated their role in bleeding disorders and thrombocytopenia. Inherited thrombocytopenias (ITs) are a heterogeneous group of disorders with varying bleeding tendencies, not simply related to platelet count.Aims:To investigate platelet, PMP and CP phenotypes and function in IT patients with different bleeding phenotypes.Methods:We enrolled 34 IT patients. Sequencing of 36 IT related genes enabled a molecular diagnosis in 47%. Bleeding phenotype was evaluated using ISTH bleeding assessment tool (BAT) with significant bleeding defined as BAT score &gt;5 (women) or &gt;3 (men). Hereby patients were divided into bleeding (n = 19) vs. non‐bleeding (n = 15) patients. Platelet, PMP and CP phenotype and function were evaluated by flow cytometry: Activation and granule release were examined by antibodies against granulphysin (CD63), P‐selectin (CD62P), activated GPIIb/IIIa (PAC‐1) and phosphatidylserine (PS) (lactadherin) unstimulated and ADP, TRAP or collagen stimulated. Coated platelets were identified as a highly granulated independent cell population appearing following collagen stimulation, gated on side scatter and GPIbα (CD42b). Normal healthy reference levels were available.Results:The platelet count in bleeding (72x109/l) and non‐bleeding (68x109/l) patients was comparable (P = 0,66). Bleeding patients had a higher BAT score compared to non‐bleeding patients (10 vs. 2, P &lt; 0,01). The proportion of CPs was normal in all patients. However, in non‐bleeding patients the proportion of PS+CPs and per cell PS expression (MFI) (86,16% and 4,96MFI) were higher, compared to bleeding patients (64,08% and 2,44MFI, both p &lt; 0,05), and the proportion of PS+CPs correlated negatively with BAT score (r2 = 0,26, p &lt; 0,01) (figure 1). CD63+CP was higher in non‐bleeding (97,25% and 10,54MFI) compared to both bleeding patients (94,88% and 6,89MFI) and significantly higher than the reference level (88,44% and 5,36MFI, both p &lt; 0,05). Finally, the proportion of PS+PMPs was normal in bleeding patients, but their PMPs expressed higher than reference PS per cell, both unstimulated and for all agonist (134,12 MFI unstimulated vs 32,38 MFI reference, P &lt; 0,01).Summary/Conclusion:Patients with IT exhibited different bleeding tendency despite comparable thrombocytopenia. In non‐bleeding patients the proportion and per cell level of PS+ were higher, indicating that generation of CPs with high PS expression is a critical factor determining bleeding phenotype. The finding of high PMP PS per cell level in bleeding patients could represent an inadequate compensation for lack of CP function, indicating that procoagulant PMPs may be less important than CPs for thrombocytopenic bleeding. Quantification and characterization of CPs may be a useful tool for future assessment of bleeding risk as well as a therapeutic target in IT and other conditions with bleeding diathesis and/or thrombocytopenia. More studies investigating this field are warranted.image