Inherited disorders of platelet function and challenges to diagnosis of mucocutaneous bleeding

"CHildren with Inherited Platelet disorders Surveillance" (CHIPS) retrospective and prospective observational cohort study by Italian Association of Pediatric Hematology and Oncology (AIEOP)

BACKGROUND

Inherited thrombocytopenias (ITs) are rare congenital bleeding disorders characterized by different clinical expression and variable prognosis. ITs are poorly known by clinicians and often misdiagnosed with most common forms of thrombocytopenia.

MATERIAL AND METHODS

"CHildren with Inherited Platelet disorders Surveillance" study (CHIPS) is a retrospective - prospective observational cohort study conducted between January 2003 and January 2022 in 17 centers affiliated to the Italian Association of Pediatric Hematology and Oncology (AIEOP). The primary objective of this study was to collect clinical and laboratory data on Italian pediatric patients with inherited thrombocytopenias. Secondary objectives were to calculate prevalence of ITs in Italian pediatric population and to assess frequency and genotype-phenotype correlation of different types of mutations in our study cohort.

RESULTS

A total of 139 children, with ITs (82 male - 57 female) were enrolled. ITs prevalence in Italy ranged from 0.7 per 100,000 children during 2010 to 2 per 100,000 children during 2022. The median time between the onset of thrombocytopenia and the diagnosis of ITs was 1 years (range 0 - 18 years). A family history of thrombocytopenia has been reported in 90 patients (65%). Among 139 children with ITs, in 73 (53%) children almost one defective gene has been identified. In 61 patients a pathogenic mutation has been identified. Among them, 2 patients also carry a variant of uncertain significance (VUS), and 4 others harbour 2 VUS variants. VUS variants were identified in further 8 patients (6%), 4 of which carry more than one variant VUS. Three patients (2%) had a likely pathogenic variant while in 1 patient (1%) a variant was identified that was initially given an uncertain significance but was later classified as benign. In addition, in 17 patients the genetic diagnosis is not available, but their family history and clinical/laboratory features strongly suggest the presence of a specific genetic cause. In 49 children (35%) no genetic defect were identified. In ninetyseven patients (70%), thrombocytopenia was not associated with other clinically apparent disorders. However, 42 children (30%) had one or more additional clinical alterations.

CONCLUSION

Our study provides a descriptive collection of ITs in the pediatric Italian population.

Epistaxis in a Pediatric Outpatient Clinic: Could It be an Alarming Sign?

Introduction Epistaxis is a common presentation among children.

Objective To investigate the suitability of a simple tool of assessment for patients with epistaxis that could guide in subgrouping those with possible bleeding tendencies who may need further assessment.

Methods Children who presented to a tertiary outpatient clinic with epistaxis of an unknown cause were recruited. They underwent thorough clinical assessment and answered the pediatric bleeding questionnaire and the epistaxis severity score. All patients underwent complete blood count as well as coagulation profile, and confirmatory diagnostic tests were performed as needed.

Results Among the 30,043 patients who presented to the outpatient clinic over a year, 100 children had epistaxis, with an estimated annual frequency of 1 in 300. A total of 84% of the patients were younger than 12, and nearly half of these were younger than 6 years. Seventy-six patients had recurrent epistaxis, and 12 had systemic comorbidities. A significant higher percentage of patients presented with epistaxis in the hot months of the year. A total of 90% of the patients presented anterior bleeding, and the majority were treated with nasal compression only. Forty-three patients presented with epistaxis only; 37 of them were diagnosed as idiopathic epistaxis, and 6 had local causes. Fifty-seven patients presented with other bleeding manifestations, 47 of whom had a definite bleeding disorder and the other 10 had undiagnosed bleeding tendency. Those with other bleeding manifestations showed a higher frequency of positive family history of epistaxis; of being referred from a primary care physician; of having alarming low platelet count, and of presenting less seasonal variability. A bleeding score ≥ 2 showed significant value in suspecting an underlying systemic pathology as a cause of epistaxis.

Conclusion The pediatric bleeding questionnaire is a useful and simple tool in the identification of pediatric patients who need further diagnostic testing to detect any underlying bleeding tendency.

Laboratory Techniques Used to Diagnose Constitutional Platelet Dysfunction

Platelets play a major role in primary hemostasis, where activated platelets form plugs to stop hemorrhaging in response to vessel injuries. Defects in any step of the platelet activation process can cause a variety of platelet dysfunction conditions associated with bleeding. To make an accurate diagnosis, constitutional platelet dysfunction (CPDF) should be considered once von Willebrand disease and drug intake are ruled out. CPDF may be associated with thrombocytopenia or a genetic syndrome. CPDF diagnosis is complex, as no single test enables the analysis of all aspects of platelet function. Furthermore, the available tests lack standardization, and repeat tests must be performed in specialized laboratories especially for mild and moderate forms of the disease. In this review, we provide an overview of the laboratory tests used to diagnose CPDF, with a focus on light transmission platelet aggregation (LTA), flow cytometry (FC), and granules assessment. Global tests, mainly represented by LTA, are often initially performed to investigate the consequences of platelet activation on platelet aggregation in a single step. Global test results should be confirmed by additional analytical tests. FC represents an accurate, simple, and reliable test to analyze abnormalities in platelet receptors, and granule content and release. This technique may also be used to investigate platelet function by comparing resting- and activated-state platelet populations. Assessment of granule content and release also requires additional specialized analytical tests. High-throughput sequencing has become increasingly useful to diagnose CPDF. Advanced tests or external research laboratory techniques may also be beneficial in some cases.

Current methods of measuring platelet activity: pros and cons

: Platelets play a pivotal role in controlling hemorrhaging from vessels of the human body. The impairment of platelets may lead to the development of bleeding manifestations. Unraveling the precise defects of platelets by means of suitable laboratory methods paves the way for the effective control and management of platelet disorders. Choosing the most appropriate approach for the detection of platelet disorders may be difficult for a researcher or clinical internist when faced with ordering a platelet-function test. The aim of the current study was to provide a user-friendly overview of the advantages and disadvantages of the available detection systems. To reach this goal, 11 commonly used methods of studying platelet activity were evaluated and compared in detail. A literature search, with no time or language limitations, was conducted in Google Scholar and Medline. All publications published before June 2019 were analyzed. The following laboratory methods were compared: number and size of platelets, bleeding time, clot retraction time, platelet function assay 100 & 200, Rapid platelet function assay, flow cytometry, light transmission aggregometry, multiple electrode aggregometry, 96-well plate aggregometry, cone and plate(let) analyzer (Impact-R), and Plateletworks (single platelet counting system). This article provides the reader with a rapid comparison of the different systems used to study platelets activities.

Platelet Disorders

After vascular injury and exposure of subendothelial matrix proteins to the intravascular space, mediators of hemostasis are triggered and allow for clot formation and restoration of vascular integrity. Platelets are the mediators of primary hemostasis, creating a platelet plug and allowing for initial cessation of bleeding. Platelet disorders, qualitative and quantitative, may result in bleeding signs and symptoms, particularly mucocutaneous bleeding such as epistaxis, bruising, petechiae, and heavy menstrual bleeding. Increasing evidence suggests that platelets have functional capabilities beyond hemostasis, but this review focuses solely on platelet hemostatic properties. Herein, normal platelet function as well as the effects of abnormal function and thrombocytopenia are reviewed.

Genetic classification and confirmation of inherited platelet disorders: current status in Korea

Inherited platelet disorders (IPDs), which manifest as primary hemostasis defects, often underlie abnormal bleeding and a family history of thrombocytopenia, bone marrow failure, hematologic malignancies, undefined mucocutaneous bleeding disorder, or congenital bony defects. Wide heterogeneity in IPD types with regard to the presence or absence of thrombocytopenia, platelet dysfunction, bone marrow failure, and dysmegakaryopoiesis is observed in patients. The individual processes involved in platelet production and hemostasis are genetically controlled; to date, mutations of more than 50 genes involved in various platelet biogenesis steps have been implicated in IPDs. Representative IPDs resulting from defects in specific pathways, such as thrombopoietin/MPL signaling; transcriptional regulation; granule formation, trafficking, and secretion; proplatelet formation; cytoskeleton regulation; and transmembrane glycoprotein signaling are reviewed, and the underlying gene mutations are discussed based on the National Center for Biotechnology Information database and Online Mendelian Inheritance in Man accession number. Further, the status and prevalence of genetically confirmed IPDs in Korea are explored based on searches of the PubMed and KoreaMed databases. IPDs are congenital bleeding disorders that can be dangerous due to unexpected bleeding and require genetic counseling for family members and descendants. Therefore, the pediatrician should be suspicious and aware of IPDs and perform the appropriate tests if the patient has unexpected bleeding. However, all IPDs are extremely rare; thus, the domestic incidences of IPDs are unclear and their diagnosis is difficult. Diagnostic confirmation or differential diagnoses of IPDs are challenging, time-consuming, and expensive, and patients are frequently misdiagnosed. Comprehensive molecular characterization and classification of these disorders should enable accurate and precise diagnosis and facilitate improved patient management.

Germline heterozygous variants in genes associated with familial hemophagocytic lymphohistiocytosis as a cause of increased bleeding

Familial hemophagocytic lymphohistiocytosis (FHL) is caused by biallelic variants in genes regulating granule secretion in cytotoxic lymphocytes. In FHL3-5, the affected genes UNC13D, STX11 and STXBP2 have further been shown to regulate the secretion of platelet granules, giving rise to compromised platelet function. Therefore, we aimed to investigate platelet degranulation in patients heterozygous for variants in UNC13D, STX11 and STXBP2. During the work-up of patients referred to the Coagulation Unit, Skåne University Hospital, Malmö, Sweden and the Department of Hematology, Rigshospitalet, Copenhagen, Denmark due to bleeding tendencies, 12 patients harboring heterozygous variants in UNC13D, STX11 or STXBP2 were identified using targeted whole exome sequencing. Transmission electron microscopy (TEM) was used to assess the secretion of platelet dense granules following thrombin stimulation. Platelet degranulation, activation and aggregation were further assessed by flow cytometry (FC) and light transmission aggregometry (LTA) with lumi-aggregometry. In total, eight out of twelve (67%) patients showed impaired degranulation by at least one of the assays (TEM, FC and LTA). In the 12 patients, eight different heterozygous variants were identified. One variant was strongly associated with impaired degranulation, while four of the variants were associated with impaired granule secretion to a slightly lesser extent. One additional variant was found in six out of the twelve patients, and was associated with varying degrees of degranulation impairment. Accordingly, six out of the eight (75%) identified variants were associated with impaired platelet degranulation. Our results suggest that heterozygous variants in UNC13D, STX11 and STXBP2 are sufficient to cause platelet secretion defects resulting in increased bleeding.

Recognition and management of platelet-refractory bleeding in patients with Glanzmann's thrombasthenia and other severe platelet function disorders

Patients with rare qualitative platelet disorders or platelet function disorders (PFDs) may present to the hospital physician with severe bleeding episodes or excessive surgical bleeding. Although standard treatment consists of platelet transfusions, repeated transfusions may result in the development of antiplatelet antibodies (APA) or clinical refractoriness, rendering further platelet therapy ineffective. In such settings, an approved treatment option for patients with Glanzmann’s thrombasthenia (GT), one of the well-known rare PFDs, is recombinant activated coagulation factor VII (rFVIIa). Data regarding the efficacy of rFVIIa in patients with GT and platelet refractoriness are available from a large patient registry, an international survey, and multiple case reports and demonstrate efficacy in patients with and without refractoriness or APA. This article reviews the rFVIIa clinical data in patients with GT and platelet refractoriness and discusses clinical implications relevant to the hospital-based physician. Because uncontrolled bleeding can be life-threatening, hospital physicians should be alert to the signs of platelet refractoriness, be able to recognize continued internal or external bleeding, and know how to adapt treatment regimens for the effective management of bleeding. The management of patients who receive rFVIIa should occur in consultation with a hematologist with experience in PFDs, and patients with suspected platelet refractoriness should be referred to such a hematologist as early as possible. A critical unmet need is the development of a definition of an adequate response to platelet transfusion, which would facilitate early recognition of platelet refractoriness in patients with PFDs who exhibit a normal platelet count.

Epistaxis as a Common Presenting Symptom of Glanzmann's Thrombasthenia, a Rare Qualitative Platelet Disorder: Illustrative Case Examples

Children often present to emergency departments (EDs) with uncontrollable nose bleeding. Although usually due to benign etiologies, epistaxis may be the presenting symptom of an inherited bleeding disorder. Whereas most bleeding disorders are detected through standard hematologic assessments, diagnosing rare platelet function disorders may be challenging. Here we present two case reports and review diagnostic and management challenges of platelet function disorders with a focus on Glanzmann's thrombasthenia (GT). Patient 1 was a 4-year-old boy with uncontrolled epistaxis. His medical history included frequent and easy bruising. Previous laboratory evaluation revealed only mild microcytic anemia. An otolaryngologist stopped the bleeding, and referral to a pediatric hematologist led to the definitive diagnosis of GT. Patient 2 was a 2.5-year-old girl with severe epistaxis and a history of milder recurrent epistaxis. She had a bruise on her abdomen with a palpable hematoma and many scattered petechiae. Previous assessments revealed no demonstrable hemostatic anomalies. Platelet aggregation studies were performed following referral to a pediatric hematologist, leading to the diagnosis of GT. As evidenced by these cases, the ED physician may often be the first to evaluate severe or recurrent epistaxis and should recognize indications for coagulation testing and hematology consultation/referral for advanced hematologic assessments.

Assessment of Platelet Function in Whole Blood by Flow Cytometry

Evaluation of platelet function is important for understanding the physiology of hemostasis and thrombosis and is utilized in clinical practice to diagnose inherited and acquired platelet bleeding disorders. Flow cytometry is a powerful tool for rapid evaluation of multiple functional properties of large number of platelets in whole blood and offers many advantages over other traditional methods. Attention to pre-analytical factors is required to ensure biologically valid and robust results.

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.

Heavy Menstrual Bleeding as a Common Presenting Symptom of Rare Platelet Disorders: Illustrative Case Examples

Heavy menstrual bleeding (HMB) is a common symptom in patients who present to the obstetrician-gynecologist or adolescent medicine specialist and might result from an underlying inherited bleeding disorder. Whereas relatively common bleeding disorders such as von Willebrand disease are often included in standard laboratory assessments, rarer platelet function disorders can be challenging to diagnose. Additionally, HMB can be a particularly difficult symptom to manage in adolescents with platelet function disorders, and it is associated with decreased quality of life. We review the diagnostic and management issues of patients with platelet function disorders through the presentation of 2 patient case reports, with a focus on a diagnosis of Glanzmann thrombasthenia, an inherited qualitative disorder that affects platelet function. Whereas the first patient presented to the emergency department before the diagnosis of a bleeding disorder and required a hematologic referral and extensive laboratory assessments, the second patient had been diagnosed with Glanzmann thrombasthenia as a child but experienced severe management challenges at the onset of menarche. In both patients, collaboration between the obstetrician-gynecologist or adolescent medicine specialist and the hematologist was critical for achieving acute management of the bleeding symptoms and for ensuring optimal long-term disease management. Together, these cases highlight the importance of properly identifying females with HMB who might have an undiagnosed bleeding disorder and of consulting with a hematologist to determine an appropriate management plan throughout all life stages.

Storage pool diseases illuminate platelet dense granule biogenesis

Platelet dense granules (DGs) are membrane bound compartments that store polyphosphate and small molecules such as ADP, ATP, Ca²⁺, and serotonin. The release of DG contents plays a central role in platelet aggregation to form a hemostatic plug. Accordingly, congenital deficiencies in the biogenesis of platelet DGs underlie human genetic disorders that cause storage pool disease and manifest with prolonged bleeding. DGs belong to a family of lysosome-related organelles, which also includes melanosomes, the compartments where the melanin pigments are synthesized. These organelles share several characteristics including an acidic lumen and, at least in part, the molecular machinery involved in their biogenesis. As a result, many genes affect both DG and melanosome biogenesis and the corresponding patients present not only with bleeding but also with oculocutaneous albinism. The identification and characterization of such genes has been instrumental in dissecting the pathways responsible for organelle biogenesis. Because the study of melanosome biogenesis has advanced more rapidly, this knowledge has been extrapolated to explain how DGs are produced. However, some progress has recently been made in studying platelet DG biogenesis directly in megakaryocytes and megakaryocytoid cells. DGs originate from an endosomal intermediate compartment, the multivesicular body. Maturation and differentiation into a DG begins when newly synthesized DG-specific proteins are delivered from early/recycling endosomal compartments. The machinery that orchestrates this vesicular trafficking is composed of a combination of both ubiquitous and cell type-specific proteins. Here, we review the current knowledge on DG biogenesis. In particular, we focus on the individual human and murine genes encoding the molecular machinery involved in this process and how their deficiencies result in disease.

Novel approaches for diagnosing inherited platelet disorders

Inherited platelet disorders diagnosis is based on the clinical history and bleeding assessment tools. The laboratory functional assays as well as the molecular test to identify the pathogenic genetic variant are essential to confirm the accurate diagnosis of these disorders. Nowadays, the main challenges to developing a new diagnostic system are involved in reducing the samples' volume, and faster and more helpful analysis. Moreover, there are no widely available and standardised global tests. High throughput genetic testing such as next-generation sequencing has revolutionised DNA sequencing technologies as it allows the simultaneous and faster investigation of multiple genes at a manageable cost. This technology has improved the molecular characterisation of inherited platelet disorders and has been implemented in the research studies and the clinical routine practice.

Diagnosis of suspected inherited platelet function disorders: results of a worldwide survey

BACKGROUND

Diagnosis of inherited platelet function disorders (IPFDs) is important for appropriate management and to improve epidemiologic and clinical knowledge. However, there remains a lack of consensus on the diagnostic approach.

OBJECTIVES

To gain knowledge on the current practices for the diagnosis of IPFD worldwide.

METHODS

A 67-item questionnaire was distributed to the ISTH members and to the members of several national hemostasis and thrombosis societies.

RESULTS

A total of 202 laboratories from 37 countries participated in the survey. The most frequent criterion to define patients with a suspected IPFD was a history of mucocutaneous bleeding and no acquired cause, but heterogeneity on the identification criteria was evident. Only 64.5% of respondents performed a direct clinical interview. On average, each laboratory studied 72 patients per year. The most commonly used laboratory equipment were the light-transmission aggregometer, the Platelet Function Analyzer-100, and the flow cytometer. Screening tests were platelet count, peripheral blood smear, light-transmission aggregometry, and Platelet Function Analyzer-100. Second-step tests were flow cytometry, molecular genetic analysis, and electron microscopy. Methodologies varied widely. In total, ~ 14,000 patients were investigated yearly and 60% turned out to not have a defect. Of the remaining 40%, only 8.7% received a diagnosis at a molecular level.

CONCLUSIONS

Many laboratories worldwide are involved in the diagnosis of IPFD. A large fraction of the patients studied remain without a diagnosis. A high variability in the diagnostic approaches is evident.

Inherited disorders of platelet function

Inherited platelet function disorders are of variable severity and unknown frequency and may be difficult to diagnose. Nevertheless, they are increasingly recognized as an important cause of bleeding in pediatrics, particularly in adolescent girls with menorrhagia, where they may be more common than von Willebrand disease. This article reviews the presentation of these disorders, summarizes the most common types of platelet function disorders, discusses the challenges in diagnostic testing, and details treatment and supportive care options.

Inherited platelet disorders and oral health

Platelets play a key role in thrombosis and hemostasis. Accumulation of platelets at the site of vascular injury is the first step in the formation of hemostatic plugs, which play a pivotal role in preventing blood loss after injury. Platelet adhesion at sites of injury results in spreading, secretion, recruitment of additional platelets, and formation of platelet aggregates. Inherited platelet disorders are rare causes of bleeding syndromes, ranging from mild bruising to severe hemorrhage. The defects can reflect deficiency or dysfunction of platelet surface glycoproteins, granule contents, cytoskeletal proteins, platelet pro-coagulant function, and signaling pathways. For instance, Bernard-Soulier syndrome and Glanzmann thrombasthenia are attributed to deficiencies of glycoprotein Ib/IX/V and GPIIb/IIIa, respectively, and are rare but severe platelet disorders. Inherited defects that impair platelet secretion and/or signal transduction are among the most common forms of mild platelet disorders and include gray platelet syndrome, Hermansky-Pudlak syndrome, and Chediak-Higashi syndrome. When necessary, desmopressin, antifibrinolytic agents, and transfusion of platelets remain the most common treatment of inherited platelet disorders. Alternative therapies such as recombinant activated factor VII are also available for a limited number of situations. In this review, we will discuss the management of patients with inherited platelet disorders in various clinical situations related to dental cares, including surgical intervention.

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.

What To Do When You Suspect an Inherited Platelet Disorder

Inherited platelet disorders (IPDs) comprise a heterogenous group of diseases that include defects in platelet function and disordered megakaryopoiesis. Some IPDs overlap as both defects in function and thrombopoiesis, resulting in both altered aggregation and/or secretion and thrombocytopenia. This review examines the key features of the presentation of IPDs in children and adults and presents a diagnostic algorithm for the evaluation of these patients. In addition, recent advances in our understanding of the pathophysiology of platelet disorders are addressed, with attention given to some of the novel genetic associations. Finally, treatment options and future therapies are briefly discussed.

Platelet disorders in children: A diagnostic approach

The investigation of children with suspected inherited platelet disorders is challenging. The causes of mucocutaneous bleeding are many, and specialized testing for platelet disorders can be difficult to access or interpret. An algorithm developed for the investigation of suspected platelet disorders provides a sequential approach to evaluating both platelet function abnormalities and thrombocytopenia. Investigation begins with a clinical evaluation and laboratory testing that is generally available, including platelet counting, peripheral blood cell morphology, and aggregometry. Based on results of initial investigations, the algorithm recommends specialized testing for specific diagnoses, including flow cytometry, immunofluorescence microscopy, electron microscopy, and mutational analysis.

Platelet disorders in adolescents

Acquired and inherited platelet disorders can present with bleeding symptoms during adolescence. Platelet disorders include disorders of platelet number and disorders of platelet function. In adolescent females with platelet disorders, menorrhagia is a common presenting bleeding symptom. Other associated bleeding symptoms are also primarily mucocutaneous, including epistaxis and bruising. Excessive bleeding may also occur after hemostatic challenges. Diagnosis of disorders of platelet function usually requires light transmission platelet aggregometry. Management of menorrhagia in the adolescent with platelet disorders requires both hematologic and gynecologic treatment.