Spectrum of Von Willebrand disease and inherited platelet function disorders amongst Indian bleeders

Investigating patients for bleeding disorders when most of the "usual" ones have been ruled out

A State of the Art lecture titled "Investigating Patients for Bleeding Disorders When Most of the Usual Ones Have Been Ruled Out" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Mild to moderate bleeding disorders (MBDs) in patients in whom no diagnosis of an established disorder, such as platelet function defect, von Willebrand disease, or a coagulation factor deficiency, can be identified are classified as bleeding disorders of unknown cause (BDUCs). Prospective data from the Vienna Bleeding Biobank and other studies have revealed a high proportion of BDUCs of up to 70% among patients with MBD who have a similar bleeding phenotype as other MBDs. As BDUC is a diagnosis of exclusion, the accuracy of the diagnostic workup is essential. For example, repeated testing for von Willebrand disease should be considered if von Willebrand factor values are <80 IU/dL. Current evidence does not support the clinical use of global assays such as thromboelastography, platelet function analyzer, or thrombin generation potential. Rare and novel bleeding disorders due to genetic variants in fibrinolytic factors or natural anticoagulants are rare and should only be analyzed in patients with specific phenotypes and a clear family history. In BDUC, blood group O was identified as a risk factor for increased bleeding severity and bleeding risk after hemostatic challenges. Future studies should improve the phenotypical characterization and ideally identify novel risk factors in BDUC, as a multifactorial pathogenesis is suspected. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress.

Health-related quality of life is impaired in bleeding disorders of unknown cause: results from the Vienna Bleeding Biobank

Background

Bleeding disorder of unknown cause (BDUC) is a diagnosis of exclusion after extensive investigation of coagulation and platelet function and is commonly seen among patients with mild-to-moderate bleeding disorders. Despite increasing awareness among treating physicians, little is known about the health-related quality of life (HrQoL) in BDUC.

Objectives

To investigate HrQoL in patients with BDUC in comparison to the general population and patients diagnosed with other established bleeding disorders.

Methods

Patients with mild-to-moderate bleeding disorders from the Vienna Bleeding Biobank, a prospective cohort study, were contacted via mail and phone to complete the 36-Item Health Survey Questionnaire form.

Results

In total, 333/657 (50.7%) patients completed the 36-Item Health Survey Questionnaire. Patients with BDUC (n = 207, 62%) had significantly impaired HrQoL both in physical (47.8 vs 49.2) and mental health parameters (42.9 vs 51.0) compared to the general population (n = 2914, 56% females), which remained after adjustment for sex and age in multivariable linear regression. The impairment in HrQoL, compared to patients with von Willebrand disease, platelet function defects, or mild clotting factor deficiencies, did not prevail after adjustment for age and sex. In patients with BDUC, age and the presence of at least 1 comorbidity were associated with impaired physical health but not sex or bleeding severity. Of all analyzed bleeding symptoms, only joint bleeding was associated with impaired physical health and gastrointestinal bleeding with mental health in BDUC.

Conclusion

The impairments in HrQoL in patients with BDUC emphasize the burden of BDUC on mental and physical well-being, encouraging early recognition and better counseling of patients with BDUC.

Spectrum of Inherited Bleeding Disorder with Special Reference to von Willebrand Disease in Eastern India

Background The objective of this study is to study the prevalence, clinical spectrum, and hematological profile of inherited bleeding disorder with special reference to von Willebrand disease in eastern India.

Materials and Methods This prospective study was done in a tertiary care center in the eastern part of India over 2 years. Detailed history and clinical findings were noted in a proforma. Laboratory analysis included prothrombin time, activated partial thromboplastin time, bleeding time, and fibrinogen assay along with tests related to specific factor assay.

Results One hundred and five patients were diagnosed as suffering with the inherited bleeding disorder out of a total of 1,204 patients. The age of patients ranged from 13 days to 35 years. The most common presenting clinical feature was prolonged bleeding after cut (76.19%). Out of 105 patients, 97 patients (92.38%) had coagulation defect, 5 patients (4.76%) had von Willebrand disease (vWD), and 3 patients (2.85%) had platelet defect. Most common coagulation defect was hemophilia A (84 cases), followed by hemophilia B (8 cases). Other rare congenital factor deficiencies were seen in five cases (5.15%). Only platelet defect was Glanzmann's thrombasthenia (GT). The age of vWD patients ranged from 4.5 years to 24 years. Forty percent patients with vWD disease were type 1 followed by 40% of type 2N and 20% of type 3 vWD.

Conclusion vWD was not so common in eastern India. vWD was present only in 4.76% cases in this study. The most common coagulation defect was hemophilia A (86.59%) in our study. GT was present in only 2.85% cases.

Screening and diagnosis of inherited platelet disorders

Inherited platelet disorders are important conditions that often manifest with bleeding. These disorders have heterogeneous underlying pathologies. Some are syndromic disorders with non-blood phenotypic features, and others are associated with an increased predisposition to developing myelodysplasia and leukemia. Platelet disorders can present with thrombocytopenia, defects in platelet function, or both. As the underlying pathogenesis of inherited thrombocytopenias and platelet function disorders are quite diverse, their evaluation requires a thorough clinical assessment and specialized diagnostic tests, that often challenge diagnostic laboratories. At present, many of the commonly encountered, non-syndromic platelet disorders do not have a defined molecular cause. Nonetheless, significant progress has been made over the past few decades to improve the diagnostic evaluation of inherited platelet disorders, from the assessment of the bleeding history to improved standardization of light transmission aggregometry, which remains a "gold standard" test of platelet function. Some platelet disorder test findings are highly predictive of a bleeding disorder and some show association to symptoms of prolonged bleeding, surgical bleeding, and wound healing problems. Multiple assays can be required to diagnose common and rare platelet disorders, each requiring control of preanalytical, analytical, and post-analytical variables. The laboratory investigations of platelet disorders include evaluations of platelet counts, size, and morphology by light microscopy; assessments for aggregation defects; tests for dense granule deficiency; analyses of granule constituents and their release; platelet protein analysis by immunofluorescent staining or flow cytometry; tests of platelet procoagulant function; evaluations of platelet ultrastructure; high-throughput sequencing and other molecular diagnostic tests. The focus of this article is to review current methods for the diagnostic assessment of platelet function, with a focus on contemporary, best diagnostic laboratory practices, and relationships between clinical and laboratory findings.

Clinicopathological Profile of the von Willebrand Disease in a Tertiary Care Centre in Varanasi

Objective  The von Willebrand disease (vWD) is one of the most common inherited bleeding disorders in India; however, the diagnostic tests and its interpretation require specialized laboratory and personnel which are not readily available in the eastern part of North India. The purpose of this study is to estimate the relative prevalence of vWD and study the clinical and laboratory features including advanced diagnostic tests.

Methods  All patients referred to the pathology department for evaluation of bleeding were evaluated for vWD during a period of 4 years. Clinical and laboratory features were analyzed and reported.

Results  A total of 1,126 cases of bleeding manifestations were evaluated, and 237 cases of inherited bleeding disorders were diagnosed; vWD was diagnosed in 38 (16%) of these 237 cases. Advanced diagnostic tests were done in all of these cases.

Conclusion  The vWD is among the most common inherited bleeding disorders in the country, second only to hemophilia A. Type-1 vWD was the most frequent with 25 cases (65.7%), followed by type-2N with 7 cases (18.4%).

Bleeding of unknown cause and unclassified bleeding disorders; diagnosis, pathophysiology and management

Bleeding of unknown cause (BUC), also known as unclassified bleeding disorders (UBD), has been defined as a clear bleeding tendency in the presence of normal haemostatic tests. There are challenges in the diagnosis and management of these patients. BUC/UBD encompasses a heterogenous group of disorders which may include undiagnosed rare monogenic diseases, polygenic reasons for bleeding; and patients without a clear bleeding disorder but with a previous bleeding event. Nevertheless, these patients may have heavy menstrual bleeding or be at risk of bleeding when undergoing surgical procedures, or childbirth; optimizing haemostasis and establishing a mode of inheritance is important to minimize morbidity. The bleeding score has been used to clinically assess and describe these patients, but its value remains uncertain. In addition, accurate distinction between normal and pathological bleeding remains difficult. Several studies have investigated cohorts of these patients using research haemostasis tests, including thrombin generation and fibrinolytic assays, yet no clear characteristics have consistently emerged. Thus far, detailed genetic analysis of these patients has not been fruitful in unravelling the cause of bleeding. There is a need for standardization of diagnosis and management guidelines for these patients. This review gives an overview of this field with some suggestions for future research.

Investigation of patients with unclassified bleeding disorder and abnormal thrombin generation for physiological coagulation inhibitors reveals multiple abnormalities and a subset of patients with increased tissue factor pathway inhibitor activity

INTRODUCTION

We have routinely used thrombin generation to investigate patients with unclassified bleeding disorder (UBD).

AIMS

To investigate haemostatic abnormalities in patients with UBD that had abnormal thrombin generation on at least one occasion.

METHODS

Investigation of 13 known UBD patients with thrombin generation and detailed haemostatic testing was undertaken including TFPI assays but also thrombomodulin and fibrinogen-γ.

RESULTS

12 females and 1 male were included. No patient had a platelet function disorder or coagulation factor deficiency that explained the bleeding phenotype, though 2 patients had factor deficiencies; a factor X of 0.41 IU/mL and a factor XI of 0.51 IU/mL. ThromboGenomics revealed variants for these factors but no other abnormalities. Patients were included who previously had either prolonged lag time or decreased endogenous thrombin potential (ETP) via high dose tissue factor (5 pmol/L) or low dose tissue factor (1.5 pmol/L) with corn trypsin inhibitor (CTI). Tissue factor pathway inhibitor (TFPI) activity was significantly increased (P < .001; increased in 8 patients) compared with controls and abnormalities in soluble thrombomodulin (2 patients), fibrinogen-γ (1 patient) and tPA (4 patients for each) were seen. Total and free TFPI levels were not increased. Mixing studies of patient plasma with 50:50 normal plasma for thrombin generation via low dose tissue factor failed to correct the ETP consistent with ongoing inhibition. Addition of an anti-TFPI antibody partially corrected thrombin generation to normal levels. TFPI sequencing was unremarkable.

CONCLUSION

TFPI activity may be increased in a subset of UBD patients. Further research studies are warranted in UBD patients for coagulation inhibitor abnormalities.

Inherited Bleeding Disorders in North Indian Children: 14 years' Experience from a Tertiary Care Center

Inherited bleeding disorders are not uncommon in pediatric practice: most of them being chronic, require lifelong replacement therapy. To frame a management policy, it is essential to assess the load and pattern of bleeding disorders in the local population. However, there is paucity of data reporting the clinical spectrum of coagulation and platelet function disorders in Indian children. Hence to find out the exact burden and clinico-investigational profile of these patients we conducted this study. In this retrospective case review, detailed clinical information was extracted from case records in 426 children with a suspected diagnosis of hereditary bleeding disorder registered in the Pediatric Hematology clinic of a tertiary referral centre over a period of 14 years (1998-2011) and pooled for analysis. In our cohort prevalence of hemophilia A, hemophilia B, platelet function disorders, von Willebrand disease and other rare factor deficiencies were 72%, 11%, 7%, 4% and 4% respectively. Common clinical spectrum included skin bleeds, arthropathy, mucosal bleeds. 10% had deeper tissue bleeding and 16% received replacement therapy at the first visit. Nearly 3/4th of cases were lost for follow up after the initial visit. Hemophilia A was the commonest inherited bleeding disorder in our population. Skin bleeds and arthropathy were common clinical presentations. Factor replacement therapy was restricted to a minority. There is an urgent need for establishing centres of excellence with administrative commitment for factor replacement therapy for comprehensive management of such children in resource-limited countries.

Diagnostic challenges of inherited mild bleeding disorders: a bait for poorly explored clinical and basic research

The best-known inherited mild bleeding disorders (MBDs), i.e. type 1 von Willebrand disease (VWD), platelet function disorders (PFDs), and mild to moderate clotting factor deficiencies, are characterized clinically by mucocutaneous bleeding, and, although they are highly prevalent, still pose difficult diagnostic problems. These include establishing the pathological nature of bleeding, and the uncertainties surrounding the clinical relevance of laboratory results. Furthermore, the high frequency of bleeding symptoms in the normal population and the subjective appraisal of symptoms by patients or parents makes elucidating the pathological nature of bleeding difficult. Standardized bleeding assessment tools and semiquantitative bleeding scores (BSs) help to discriminate normal from abnormal bleeding. However, as most MBDs have similar bleeding patterns, for example, bleeding sites, frequency, and severity, BSs are of little help for diagnosing specific diseases. Global tests of primary hemostasis (bleeding time; PFA-100/200) lack sensitivity and, like BSs, are not disease-specific. Problems with the diagnosis of type 1 VWD and PFD include assay standardization, uncertain definition of von Willebrand factor cut-off levels, and the lack of universal diagnostic criteria for PFD. Regarding clotting factor deficiencies, the bleeding thresholds of some coagulation factors, such as factor VII and FXI, are highly variable, and may lead to misinterpretation of the clinical relevance of mild to moderate deficiencies. Remarkably, a large proportion of MBDs remain undiagnosed even after comprehensive and repeated laboratory testing. These are tentatively considered to represent bleeding of undefined cause, with clinical features indistinguishable from those of classical MBD; the pathogenesis of this is probably multifactorial, and unveiling these mechanisms should constitute a fertile source of translational research.

A study to determine the prevalence, clinical profile and incidence of formation of inhibitors in patients of hemophilia in North Eastern part of India

Introduction:

Deficiency of factor VIII (Hemophilia A), factor IX (Hemophilia B) and Von Willebrand's factor are the most frequent coagulation defects. The incidence of inhibitors in patients of factor VIII deficiency is varies in different regions of India.

Aim:

To determine the prevalence, clinical profile and incidence of formation of inhibitors in patients of Hemophilia in north eastern part of India.

Methods:

Selected patients were under went for complete Blood Count (CBC), General Blood Picture (GBP), Prothrombin time (PT), Activated partial thromboplastin time (APTT), Thrombin time, Correction experiment to know the specific factor deficiency or inhibitors present by Normal Plasma, Normal aged serum, Al(OH)₃ adsorbed plasma.

Results:

92 patients diagnosed as suffering with Hemophilia A or B were included in study. The age of patients ranged from 2.5 month to 53 years. Out of 92, seventy nine (85.87%) were Haemophilia A and thirteen were (14.13%) Hemophilia B patients. 3.50% (2/55) cases of treated Hemophilia A patient develop inhibitor.

Conclusion:

The prevalence of hemophilia and incidence of inhibitors in these patients is varies in different regions of India. This variation may be due to the type of product used as treatment, intensity of treatment or the genetic characteristics of the patients.

High proportion of patients with bleeding of unknown cause in persons with a mild-to-moderate bleeding tendency: Results from the Vienna Bleeding Biobank (VIBB)

INTRODUCTION

Data on clinical characteristics and the prevalence of underlying coagulopathies in patients with mild-to-moderate bleeding disorders (MBDs) are scarce.

AIM

We established the Vienna Bleeding Biobank (VIBB) to characterize and thoroughly investigate Austrian patients with MBDs.

RESULTS

Four hundred eighteen patients (female = 345, 82.5%) were included. A platelet function defect (PFD) was diagnosed in 26 (6.2%) and a possible PFD in 30 (7.2%) patients. Eight patients (1.9%) were diagnosed with von Willebrand disease (VWD) (type 1 n = 6; type 2 n = 2), and 29 patients had low VWF (30-50 IU/dL). Deficiencies in factor VIII, IX, XI or XIII were found in 11 (2.6%), 3 (0.7%), 3 (0.7%) and 1 patient(s), 2 patients had dysfibrinogenaemia, and further 2 had possible PFD and FXI deficiency. Probable causal mutations were detected in 8 of 11 patients with FVIII deficiency, 2 of 3 patients with FIX deficiency and 2 of 8 patients with VWD. Three hundred three patients (72.5%) had normal results in the coagulation assays and were categorized as patients with bleeding of unknown cause (BUC). The bleeding score did not differ between patients with and without established diagnosis. A diagnosis of a bleeding disorder was more frequently made in men than in women (49.3% vs 22.9%). Male sex (OR 3.55, 95% CI: 2.02-6.22; P < .001) and blood group 0 (OR 1.86, 95% CI: 1.17-2.94; P = .008) were independently associated with diagnosis of a bleeding disorder.

CONCLUSION

The high rate of patients with BUC despite in-depth haemostatic assessment underlines the incompleteness of available routine laboratory tests. Males with MBDs were more likely to be diagnosed with an established bleeding disorder than females.

A review of platelet secretion assays for the diagnosis of inherited platelet secretion disorders

Measurement of platelet granule release to detect inherited platelet secretion disorders (IPSDs) is essential for the evaluation of patients with abnormal bleeding and is necessary to distinguish which granule sub-types are affected and whether there is abnormal granule bio-synthesis or secretion. The radioactive serotonin incorporation and release assay, described before 1970, is still considered the “gold standard” test to assess platelet δ-granule release, although is unsuitable for clinical diagnostic laboratories. Luciferin-based assays, such as lumiaggregometry, are the most widely performed alternatives, although these methods do not distinguish defects in δ-granule biosyn-thesis from defects in secretion. Platelet α-granule release is commonly evaluated using flow cytometry by measuring surface exposure of P-selectin after platelet activation. However, this assay has poor sensitivity for some α-granule disorders. Only few studies have been published with more recently developed assays and no critical reviews on these methods are available. In this review, we describe the rationale for developing robust and accurate laboratory tests of platelet granule release and describe the characteristics of the currently available tests. We identify an unmet need for further systematic evaluation of new assays and for standardisation of methodologies for clinical diagnostic laboratories.

Challenges on the diagnostic approach of inherited platelet function disorders: Is a paradigm change necessary?

Inherited platelet function disorders (IPFD) have been assessed for more than 50 years by aggregation- and secretion-based tests. Several decision trees are available intending to standardize the investigation of IPFD. A large variability of approaches is still in use among the laboratories across the world. In spite of costly and lengthy laboratory evaluation, the results have been found inconclusive or negative in a significant part of patients having bleeding manifestations. Molecular investigation of newly identified IPFD has recently contributed to a better understanding of the complexity of platelet function. Once considered "classic" IPFDs, Glanzmann thrombasthenia and Bernard-Soulier syndrome have each had their pathophysiology reassessed and their diagnosis made more precise and informative. Megakaryopoiesis, platelet formation, and function have been found tightly interlinked, with several genes being involved in both inherited thrombocytopenias and impaired platelet function. Moreover, genetic approaches have moved from being used as confirmatory diagnostic tests to being tools for identification of genetic variants associated with bleeding disorders, even in the absence of a clear phenotype in functional testing. In this study, we aim to address some limits of the conventional tests used for the diagnosis of IPFD, and to highlight the potential contribution of recent molecular tools and opportunities to rethink the way we should approach the investigation of IPFD.

Flow cytometry-based platelet function testing is predictive of symptom burden in a cohort of bleeders

Platelet function disorders (PFDs) are common in patients with mild bleeding disorders (MBDs), yet the significance of laboratory findings suggestive of a PFD remain unclear due to the lack of evidence for a clinical correlation between the test results and the patient phenotype. Herein, we present the results from a study evaluating the potential utility of platelet function testing using whole-blood flow cytometry in a cohort of 105 patients undergoing investigation for MBD. Subjects were evaluated with a test panel comprising two different activation markers (fibrinogen binding and P-selectin exposure) and four physiologically relevant platelet agonists (ADP, PAR1-AP, PAR4-AP, and CRP-XL). Abnormal test results were identified by comparison with reference ranges constructed from 24 healthy controls or with the fifth percentile of the entire patient cohort. We found that the abnormal test results are predictive of bleeding symptom severity, and that the greatest predictive strength was achieved using a subset of the panel, comparing measurements of fibrinogen binding after activation with all four agonists with the fifth percentile of the patient cohort (p = 0.00008, hazard ratio 8.7; 95% CI 2.5-40). Our results suggest that whole-blood flow cytometry-based platelet function testing could become a feasible alternative for the investigation of MBDs. We also show that platelet function testing using whole-blood flow cytometry could provide a clinically relevant quantitative assessment of platelet-related hemostasis.

Laboratory evaluation of patients with undiagnosed bleeding disorders

The evaluation of patients with a bleeding tendency represents a challenge as the routinely available tests for evaluating bleeding disorders are limited, complicating the laboratory determination of the clinically observed bleeding tendency. As a result, some bleeding disorders remain undiagnosed. The aim of the study was to evaluate whether global coagulation tests would contribute to the laboratory analysis of patients with undiagnosed bleeding disorders. Patients were evaluated for coagulation and fibrinolysis activities by thrombin generation test and euglobulin lysis time. In addition, plasma activity of factor XIII, plasminogen, α-2 antiplasmin, plasminogen activator inhibitor-1, and thrombin-activatable fibrinolysis inhibitor was also obtained. Forty-five patients were included. Eight per cent presented a mild bleeding disorder and 20% a moderate bleeding disorder. The thrombin generation test results were similar between patients and controls. Euglobulin lysis time results, however, were lower in patients than in controls, both before (median 175 vs. 250 min, respectively; P = 0.003) and after (median 145 vs. 115 min, respectively; P ≤ 0.001) arm constriction, suggesting that they were experiencing hyperfibrinolysis. Interestingly, patients' median thrombin-activatable fibrinolysis inhibitor activity was higher than in controls (21.2 vs. 19.46 μg/ml; P = 0.016). However, plasminogen, α-2 antiplasmin, plasminogen activator inhibitor-1, and factor XIII activities did not differ between the groups. Global coagulation and fibrinolysis tests proved to be limited in detecting the hemostatic disorders in some patients with a relevant bleeding tendency and may not be adequate to address their bleeding risk. Bleeding scores are currently the available medical approach for the evaluation of these patients.

A longitudinal prospective study of bleeding diathesis in Egyptian pediatric patients: single-center experience

Keeping an updated registry of bleeding disorders is crucial for planning care and documenting prevalence. We aimed to assess the prevalence of various bleeding disorders including rare inherited coagulation and platelet disorders concerning their clinico-epidemiological, diagnostic data and bleeding manifestations severity. Patients suffering from manifestations of bleeding or coagulation disorders presented to Hematology Clinic during 16 years were included and prospectively followed up. Demographics, clinical characteristics, complete blood count, bleeding, prothrombin and activated partial thromboplastin times, platelet aggregation tests and bone marrow aspiration were recorded. Overall 687 patients with bleeding disorders from total 2949 patients were identified. Inherited coagulation defects were found in 27.2%; hemophilia A (70.6%), hemophilia B (13.9%), factor I deficiency (2.3%), factor V deficiency (1.6%), factor X deficiency (4.2%), factor VII deficiency (2.6%), factor XIII deficiency (1.1%), combined factor deficiency (2.1%) and unclassified coagulation disorders in 1.6% of studied patients. Overall 72.7% had diagnosed with platelet disorders; immune thrombocytopenia was the commonest (74.8%), and inherited conditions represent (25.2%) in the following order: Glanzman's thrombasthenia (11.2%), von Willebrand disease (6.6%), Bernard-Soulier syndrome (1%) and Chediak Higashi in 0.4% and unclassified in 6%. Median age of diagnosis of coagulation and platelet disorders were 33 and 72 months. Presenting symptoms of coagulation disorders were: 25.1% post circumcision bleeding, 22.5% ecchymosis, 20.9% hemoarthrosis and 15% epistaxis. Symptoms of rare coagulation disorders were postcircumcision bleeding (20%), bleeding umbilical stump (20%), epistaxis (12%), hemoarthrosis (8%) and hematomas (4%). Presenting symptoms in rare inherited platelet disorders were purpura, ecchymosis, epistaxis and bleeding gums, respectively. Analysis of the clinico-epidemiological data of patients with bleeding disorders is a useful tool for monitoring and improving their quality of care.

Is my patient a bleeder? A diagnostic framework for mild bleeding disorders

Congenital mild bleeding disorders (MBDs) are very prevalent and are the source of frequent diagnostic problems. Most MBDs are categorized as disorders of primary hemostasis (ie, type 1 VWD and platelet function disorders), but mild or moderate deficiencies of clotting factors and some rare hyperfibrinolytic disorders are also included. These patients have abnormal bleeding from the skin and mucous membranes, menorrhagia, and disproportionate hemorrhages after trauma, invasive procedures, and surgery. This review addresses the main problems that physicians and hemostasis laboratories confront with the diagnosis of these patients, including: discerning normal/appropriate from pathological bleeding, the role and yield of screening tests, the lack of distinctive bleeding pattern among the different diseases, the inherent difficulties in the diagnosis of type 1 VWD and the most common platelet functional disorders, improvements in assays to measure platelet aggregation and secretion, and the evidence that most of the patients with MBDs end up without a definite diagnosis after exhaustive and repeated laboratory testing. Much research is needed to determine the pathogenesis of bleeding in MBD patients. Better standardization of current laboratory assays, progress in the knowledge of fibrinolytic mechanisms and their laboratory evaluation, and new understanding of the factors contributing to platelet-vessel wall interaction, along with the corresponding development of laboratory tools, should improve our capacity to diagnose a greater proportion of patients with MBDs.

Bleeding symptoms in heterozygous carriers of inherited coagulation disorders in southern Iran

The objective of the present study was to investigate the prevalence of bleeding symptoms in individuals who are heterozygous for recessively inherited coagulation disorders (RICDs) and to determine the association of these bleeding symptoms with type of RICDs. This was a retrospective cross-sectional study being performed in Shiraz Hemophilia Society (Shiraz, Southern Iran). In this study, bleeding symptoms of the parents (heterozygous) of the patients (homozygous) who were registered and had definite diagnosis as autosomal recessive coagulation disorder were evaluated. These inherited disorders include factor I, V, VII, X, XI, XIII deficiency, combined factor VII and X deficiency, combined factor V and VIII deficiency, all platelet disorders and von Willebrand disease (VWD) type III. 50.3% individuals underwent genotype and mutation study to confirm their heterozygosity. We included 350 heterozygote individuals for inherited coagulation disorders among whom there were 175 (50%) men and 175 (50%) women. Those who were heterozygous for factor VII deficiency had significantly higher prevalence of subcutaneous hematoma (P=0.011). In the same way heterozygous patients for Bernard-Soulier syndrome had higher prevalence of hypermenorrhea (P=0.012) and obstetric (normal vaginal delivery or cesarean delivery) bleeding (P=0.012). Heterozygosity for factor X and XIII deficiency was associated with prolonged or massive bleeding during operations (P=0.001) and after minor traumas (P=0.019), respectively. Heterozygosity for RICDs is associated with some bleeding symptoms. Thus bleeding tendency and homeostasis disturbance should be kept in mind in those who are heterozygous for RICDs and more preoperative care and correction of coagulation indices is highly recommended.

Congenital bleeding disorders in Karachi, Pakistan

OBJECTIVE

To determine the frequency of inherited bleeding disorders, its complications, and treatment modalities available for its treatment.

DESIGN

Cross-sectional study.

PATIENTS AND METHODS

Patients with a history of bleeding tendency were tested for confirmation of the diagnosis. History and clinical findings were recorded. Laboratory analysis included prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time (BT), and fibrinogen assay. Patients with prolonged APTT were tested for factors VIII (FVIII) and IX (FIX). If FVIII was low, von Willebrand factor: antigen (vWF:Ag) and von Willebrand factor:ristocetin cofactor (vWF:RCo) were performed. When PT and APTT both were prolonged, FV, FX, and FII were tested. Platelet aggregation studies were done when there was isolated prolonged BT. Urea clot solubility test was done when all coagulation tests were normal. All patients with hemophilia A and B were evaluated for inhibitors.

RESULTS

Of the 376 patients, inherited bleeding disorder was diagnosed in 318 (85%) cases. Median age of patients was 16.4 years. Hemophilia A was the commonest inherited bleeding disorder that was observed in 140 (37.2%) followed by vWD 68 (18.0%), platelet function disorders 48 (12.8%), and hemophilia B in 33 (8.8%) cases. We also found rare congenital factor deficiencies in 13 (3.4%), low VWF in 11 (3.0%) participants and 5 (1.3%) in female hemophilia carriers. Hemarthrosis was the most frequent symptom in hemophilia A and B (79.7%) involving knee joint. Inhibitor was detected in 21 (15%) cases. Fresh frozen plasma/cryoprecipitate were the most common modality of treatment. In 58 patients, no abnormality was detected in coagulation profile.

CONCLUSION

Hemophilia A and vWD are the most common congenital bleeding disorders in this study. Hemarthrosis involving knee joint was the most common complication. Inhibitor was detected in a significant number of patients. Plasma is still the most common modality of treatment.

Clinical features and types of von Willebrand disease in Karachi

This study was conducted on patients with a history of congenital bleeding disorders or with suspected bleeding tendencies. Laboratory analysis revealed Von Willebrand disease (VWD) in 68 (21.3%) of 318 participants with male to female ratio of 0.8: 1 (31 to 37) and median age 17 years (range 2-45 years). Type 3 being the most frequent, 35 (51.4%) of 68, type 2, 20 (29.4%) of 68, and lastly type 1, 13 (19.1%) of 68. A total of 55.8% patients with VWD presented with mucocutaneous bleeding. Menorrhagia was the most common presentation of female patients. Von Willebrand disease (21.3%) was the second common bleeding disorder and the most common coagulation defect among females with menorrhagia. However, the frequency in the study was quite low when compared to the western world. Similarly, low frequency of VWD type 1 might be due to the fact that only symptomatic patients visited us. Further studies are needed as there is limited information on VWD in the developing countries. This will help in the development of expertise for the accurate diagnosis & proper management.

Spectrum of inherited bleeding disorders in southern Iran, before and after the establishment of comprehensive coagulation laboratory

The objective of the present study was to determine the pattern of inherited bleeding disorders in southern Iran and evaluate the effect of a comprehensive coagulation laboratory and related efforts. A total of 545 patients with inherited bleeding disorders were evaluated during 1992-2007 by a cross-sectional study. Data were collected by a data-gathering form. Statistical analysis was done using Statistical Package for the Social Sciences version 15. A P value less than 0.05 was considered statistically significant. Overall 411 patients had common bleeding disorders including 326 hemophilia A, 46 hemophilia B, and 39 von Willebrand disease. Seventy-nine patients had rare coagulation disorders including deficiency of factor VII (n = 26), factor X (n = 18), factor XIII (n = 9), factor I (n = 9), factor XI (n = 7), factor V (n = 4), combined factor VIII and factor V (n = 4), and combined factor X and factor VII (n = 2). Fifty-five patients had platelet disorders including 23 with Glanzmann's thrombasthenia, 15 with Bernard-Soulier syndrome, and 17 with other platelet disorders, most of which (45) were diagnosed after the establishment of the comprehensive coagulation laboratory. Annual mean number of new diagnosed patients with common and rare bleeding disorders increased from 29 +/- 4 to 38 +/- 17. The ratio of the patients diagnosed with rare bleeding disorders to common bleeding disorders significantly increased after the establishment of the comprehensive diagnosis laboratory (P < 0.001).It seems that implementation of collaborative projects by the Shiraz Hemophilia Society and the establishment of the comprehensive coagulation laboratory and treatment centers have been successful in increasing diagnosis of the inherited bleeding disorders and consequently better management of the patients.

Acquired Platelet Dysfunction in 109 Patients From a Tertiary Care Referral Hospital

Background: Acquired platelet function defects (PFDs) remain poorly characterized, underrecognized, and therefore understudied. Patients/Methods: Clinical and laboratory records of 109 patients with acquired PFDs diagnosed over 5 years were analyzed. Screening studies (platelet count, prothrombin time, activated partial thromboplastin time, and thrombin time), template bleeding time, platelet factor 3 (PF-3) availability test, light-transmission aggregometry, and further testing as indicated were performed. Results: 64 patients had mild and 26 had major bleeding. In all, 15 were referred for preoperative testing, whereas 4 had thrombotic events. Causes and associations of PFDs were drug-induced (34), idiopathic (34), hematopoietic neoplasms (15; myeloma 4, Waldenstrom macroglobulinemia 2, chronic myeloid leukemia 4, essential thrombocythaemia 3, and primary myelofibrosis and chronic lymphocytic leukemia 1 each), chronic liver disease (4), postcardiac surgery (2), uremia (2), and thalassemia major (7). Miscellaneous disorders comprised the rest. Conclusions: Acquired PFDs span a wide range of disease settings. Systematic, sequential laboratory testing identifies patterns of dysfunction, excludes inherited disorders, and streamlines management.