The utility of International Society on Thrombosis and Haemostasis-Bleeding Assessment Tool and other bleeding questionnaires in assessing the bleeding phenotype in two platelet function defects

Association of laboratory test results with the bleeding history in patients with inherited platelet function disorders (the Bleeding Assesment Tool - LABoratory tests substudy): communication from the Platelet Physiology ISTH-SSC

Background

In hemophilia and von Willebrand disease, the degree of alteration of laboratory assays correlates with bleeding manifestations. Few studies have assessed the predictive value for bleeding of laboratory assays in patients with inherited platelet function disorders (IPFDs).

Objectives

To assess whether there is an association between platelet function assay results and bleeding history, as evaluated by the International Society on Thrombosis and Haemostasis (ISTH) bleeding assessment tool (BAT).

Methods

Centers participating in the international ISTH-BAT validation study were asked to provide results of the diagnostic assays employed for the patients they enrolled, and the association with the individual patients' bleeding score (BS) was assessed.

Results

Sixty-eight patients with 14 different IPFDs were included. Maximal amplitude of platelet aggregation was significantly lower in patients with a pathologic BS and correlated inversely with the BS, a finding largely driven by the subgroup of patients with Glanzmann thrombasthenia and CalDAG-GEFI deficiency; after their exclusion, TRAP-induced aggregation remained significantly lower in patients with a pathologic BS. Bleeding time was significantly more prolonged in patients with a high BS than in those with a normal BS (27.1 ± 6.2 minutes vs 15.1 ± 10.6 minutes; P < .01). Reduced α-granule content was significantly more common among patients with a pathologic BS than among those with a normal BS (80% vs 20%; P < .05). Receiver operating characteristic curve analysis revealed a significant discriminative ability of all the aforementioned tests for pathologic BS (P < .001), also after exclusion of patients with Glanzmann thrombasthenia and CalDAG-GEFI deficiency.

Conclusion

This study shows that altered platelet laboratory assay results are associated with an abnormal ISTH-BAT BS in IPFD.

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

BACKGROUND

The bleeding risk of patients with mild platelet function disorders is difficult to assess and their phenotype remains ill-explored.

AIM

This study was designed to establish a comprehensive biological phenotype of patients with mild platelet function disorders.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Use of electronic self-administered bleeding assessment tool in diagnosis of paediatric bleeding disorders

INTRODUCTION

In the era of electronic medical records, pen-and-paper-based physician-administered bleeding assessment tools (BAT) remain under-utilized in the clinical setting, as they are noted to be time-consuming.

AIM

The current study reviews the use of an electronic self-administered bleeding assessment tool (eBAT) prospectively in a paediatric haematology clinic and in comparison with a physician administered BAT (pBAT).

MATERIALS AND METHODS

This was reviewed and approved in the current form because the aims statement includes the method regarding comparison of 2 groups. So no additional section required.

RESULTS

A total of 94 BAT response pairs were available for analysis. The median time required for patients or parents to complete the eBAT was 8 min, with less than a third of the patients requiring over 10 min. The median bleeding scores noted in this study were 4 for both the BATs, with strong positive correlation between the eBAT and the physician administered bleeding questionnaire. The eBAT had a sensitivity of 93.8% (95% CI 82.8%-98.7%), a specificity of 34.8% (95% CI 21.4%-50.3%), a positive predictive value (PV) of 60.0% (95% CI 54.5%-65.2%) and a negative PV of 84.2% (95% CI 62.5%-94.5%) for identifying a bleeding disorder.

CONCLUSIONS

Findings indicate that eBAT is a valid and time-efficient screening tool for evaluating patients' bleeding symptoms, which can improve clinical applicability of BATs by reducing time for bleeding history review.

The ISTH bleeding assessment tool as predictor of bleeding events in inherited platelet disorders: Communication from the ISTH SSC Subcommittee on Platelet Physiology

BACKGROUND

The ISTH Bleeding Assessment Tool (ISTH-BAT) has been validated for clinical screening of suspected von Willebrand disease (VWD) and for bleeding prediction. Recently it has been validated for subjects with inherited platelet disorders (IPD) (BAT-VAL study).

OBJECTIVES

To determine whether the ISTH-BAT bleeding score (BS) predicts subsequent bleeding events requiring treatment in IPD patients.

METHODS

Patients with IPD, type 1 VWD (VWD-1) and age- and sex-matched healthy controls enrolled in the BAT-VAL study were prospectively followed-up for 2 years and bleeding episodes requiring treatment were recorded.

RESULTS

Of the 1098 subjects initially enrolled, 955 were followed-up and 124 suffered hemorrhages during follow-up, 60% of whom had inherited platelet function disorders (IPFD). Total number of events was significantly higher in IPFD (n = 235) than VWD-1 (n = 52) or inherited thrombocytopenia (IT; n = 20). Events requiring transfusions were 66% in IPFD, 5.7% in VWD-1, and 3% in IT. Baseline BS was significantly higher in IPFD patients with a bleeding event at follow-up than in those without (p < .01) and the percentage of subjects suffering a bleeding event increased proportionally to baseline BS quartile. A significant association between the BS and the chance of suffering severe bleeding was found in the overall, IPFD, and VWD-1 populations. Similar results were obtained for the pediatric population.

CONCLUSIONS

Inherited platelet function disorder patients with high BS at enrollment are more likely to suffer from bleeding events requiring treatment at follow-up. Moreover, the higher the baseline BS quartile the greater the incidence of subsequent events, suggesting that independently from diagnosis a high BS is associated with a greater risk of subsequent hemorrhage.

Translation, validation, and usability of the International Society on Thrombosis and Haemostasis Bleeding Assessment Tool (Self-ISTH-BAT)

BACKGROUND

Bleeding questionnaires are effective and recommended screening tools for potential bleeding disorder, but healthcare practitioner-administered bleeding assessment tools (expert-ISTH-BATs) are time-consuming. A patient-administered ISTH-BAT (self-ISTH-BAT) has been developed and validated. We translated, validated, and evaluated the usability of self-ISTH-BAT.

METHODS

We conducted a forward-backward translation of self-ISTH-BAT from English to Danish. Expert-ISTH-BAT and Danish self-ISTH-BAT were administered to 106 random individuals aged ≥18 years attending Odense University Hospital between August and November 2020 for elective blood sampling. Results comprise a score of bleeding symptoms.

RESULTS

Mean age of included individuals were 49 years (range: 18-83), and 59% were female. Median self-ISTH-BAT score was 2 (range: 0-18) and 1 (range: 0-22) for expert-ISTH-BAT (P = .09). All organ systems had ≥90% exact score agreement between expert-ISTH-BAT and self-ISTH-BAT, except gastrointestinal bleeding (77%) and other bleedings (72%). We found an acceptable correlation (r²  = .80) between expert-ISTH-BAT and self-ISTH-BAT. The self-ISTH-BAT had 82% sensitivity and 89% specificity at the recommended cutoff for expert-BAT (female:<6; male:<4). At this cutoff, 10 had abnormal self-ISTH-BAT scores with normal expert-ISTH-BAT. Three (3%) had normal self-ISTH-BAT with abnormal expert-ISTH-BAT.

CONCLUSION

Self-ISTH-BAT can replace expert-ISTH-BAT as a screening tool for bleeding disorders in Danish individuals as only 3% were not identified with the self-ISTH-BAT tool.

Prospective evaluation of ISTH-BAT as a predictor of bleeding disorder in adolescents presenting with heavy menstrual bleeding in a multidisciplinary hematology clinic

BACKGROUND

Heavy menstrual bleeding (HMB) can be the first manifestation of an undiagnosed bleeding disorder (BD). Identifying a BD can be challenging in the adolescent age group. The utility of bleeding assessment tools (BAT) remains elusive in this population.

AIM

We evaluated the ability of the International Society on Thrombosis and Haemostasis-BAT (ISTH-BAT) in predicting a BD in adolescents referred for HMB to a multidisciplinary hematology clinic.

METHODS

Two hundred adolescents with HMB underwent a standardized evaluation for BD. The clinical characteristics, laboratory data, and bleeding scores (BS) assessed using ISTH-BAT were prospectively collected. Comparisons were made between patients based on the diagnosis of BD receiver operating characteristic (ROC) curve analyses of ISTH-BAT were performed to assess its value for predicting BD.

RESULTS

Overall, 33% (n = 67) of adolescents were diagnosed with a BD. The mean ISTH-BAT BS was higher in BD as compared to those without (4.1 versus 3.1, P < .0001), but the mean menorrhagia-specific scores did not differ (2.9 in both groups). The ISTH-BAT demonstrated a modest discriminative ability as a screening tool to identify BD in girls with HMB with an area under the curve (AUC) of 0.71. The ROC analysis demonstrated that with increasing BS, the sensitivity decreased, but the specificity increased. At BS = 3, sensitivity was 88%, specificity 31%, and accuracy 50%; at BS = 5, sensitivity was 37%, specificity 94%, and accuracy was 75%. There was no change thereafter.

CONCLUSION

In adolescents with HMB, an ISTH-BAT BS of >4 instead of the established cut-off of >2 in children is highly specific in predicting a BD.

Validation of the ISTH/SSC bleeding assessment tool for inherited platelet disorders: A communication from the Platelet Physiology SSC

BACKGROUND

Careful assessment of bleeding history is the first step in the evaluation of patients with mild/moderate bleeding disorders, and the use of a bleeding assessment tool (BAT) is strongly encouraged. Although a few studies have assessed the utility of the ISTH-BAT in patients with inherited platelet function disorders (IPFD) none of them was sufficiently large to draw conclusions and/or included appropriate control groups.

OBJECTIVES

The aim of the present study was to test the utility of the ISTH-BAT in a large cohort of patients with a well-defined diagnosis of inherited platelets disorder in comparison with two parallel cohorts, one of patients with type-1 von Willebrand disease (VWD-1) and one of healthy controls (HC).

PATIENTS/METHODS

We enrolled 1098 subjects, 482 of whom had inherited platelet disorders (196 IPFD and 286 inherited platelet number disorders [IT]) from 17 countries.

RESULTS

IPFD patients had significantly higher bleeding score (BS; median 9) than VWD-1 patients (median 5), a higher number of hemorrhagic symptoms (4 versus 3), and higher percentage of patients with clinically relevant symptoms (score > 2). The ISTH-BAT showed excellent discrimination power between IPFD and HC (0.9 < area under the curve [AUC] < 1), moderate (0.7 < AUC < 0.9) between IPFD and VWD-1 and between IPFD and inherited thrombocytopenia (IT), while it was inaccurate (AUC ≤ 0.7) in discriminating IT from HC.

CONCLUSIONS

The ISTH-BAT allows to efficiently discriminate IPFD from HC, while it has lower accuracy in distinguishing IPFD from VWD-1. Therefore, the ISTH-BAT appears useful for identifying subjects requiring laboratory evaluation for a suspected IPFD once VWD is preliminarily excluded.

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

Essentials The utility of bleeding assessment tools regarding platelet function disorders is still elusive. We studied consecutive patients in a prospective cohort study in a tertiary hospital. Substantially higher scorings were observed in patients with platelet function disorders. Bleeding assessment tools might provide a useful screening tool.

BACKGROUND

Bleeding 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.

AIM

We aimed to assess the diagnostic value of the International Society on Thrombosis and Haemostasis BAT (ISTH-BAT) for platelet function disorders in clinical practice.

METHODS

The 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.

RESULTS

Five 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).

CONCLUSIONS

Presence 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.

Diagnosis of inherited bleeding disorders in the genomic era

Inherited bleeding disorders affect between 1 in 1000 individuals for the most common disorder, von Willebrand Disease, to only 8 reported cases worldwide of alpha-2-antiplasmin deficiency. Those with an identifiable abnormality can be divided into disorders of coagulation factors (87%), platelet count and function (8%) and the fibrinolytic system (3%). Of the patients registered in the UK with a bleeding disorder, the remaining 2% are unclassifiable. In addition to bleeding symptoms, patients with an inherited bleeding disorder can manifest other abnormalities, making an accurate and complete diagnosis that reflects the underlying molecular pathology important. Although some inherited bleeding disorders can still be easily diagnosed through a combination of careful clinical assessment and laboratory assays of varying degrees of complexity, there are many where conventional approaches are inadequate. Improvements in phenotyping assays have enhanced our diagnostic armoury but genotyping now offers the most accurate and complete diagnosis for some of these conditions. The advent of next generation sequencing technology has meant that many genes can now be analysed routinely in clinical practice. Here, we discuss the different diagnostic tools currently available for inherited bleeding disorders and suggest that genotyping should be incorporated at an early stage in the diagnostic pathway.

Quantitation of bleeding symptoms in a national registry of patients with inherited platelet disorders

BACKGROUND

Inherited platelet deficiency and/or dysfunction may be more common in the general population than has previously been appreciated. In 2013 the Israeli Inherited Platelet Disorder (IPD) Registry was established.

METHODS

Clinical and laboratory data were collected to pre-specified registration forms. The study protocol was approved by the local hospital ethics committees.

RESULTS

To date we have included in the registry 89 patients (male 52%) from 79 families. Most patients (74%) have a not-yet specified inherited thrombocytopenia (n=39) or non-specific platelet function disorder (n=27). Full clinical data were available for 81 (91%) patients. The median (range) age at presentation and time of follow-up were 1.8years (1day-17.8years) and 4.7 (0-26) years, respectively. The Pediatric Bleeding Questionnaire was available for 78patients; abnormal bleeding score (≥2) was recorded in 47 (52.8%, 95% CI 42%-63.5%) patients and was less frequent in patients followed for isolated thrombocytopenia. Abnormal score was associated with a longer time of follow-up, OR 1.19 (95% CI 1.04-1.36).

CONCLUSION

Long term follow-up of patients with IPDs is important as bleeding risks may increase with time. We expect that clinical and laboratory information of patients/families with IPDs gathered in a systemic format will allow for better diagnosis and treatment of these patients.