Allogeneic hematopoietic cell transplantation in an adult patient with Glanzmann thrombasthenia

Should HLA and HPA-matched platelet transfusions for patients with Glanzmann Thrombasthenia or Bernard-Soulier syndrome be standardized care? A Dutch survey and recommendations

BACKGROUND

Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) patients require frequent platelet transfusions and hence have an increased risk for alloimmunization against donor Human Leukocyte Antigens (HLA) when no HLA-matching is performed. Knowing that Human Platelet Antigens (HPA) are located on the platelet glycoproteins that can be absent in these patients, preventive HPA-matching may also be considered. Uniform recommendations on this topic lack in transfusion guidelines making standard practice unclear, therefore, we aimed to provide a framework for matched platelet transfusions.

STUDY DESIGN AND METHODS

We conducted a targeted literature search and a national survey of Dutch (pediatric) hematologists from July to September 2021.

RESULTS

We found 20 articles describing platelet transfusion policies in 483 GT-patients and 29 BSS-patients, both adults and children. Twenty surveys were returned for full analysis. All responders treated patients with platelet disorders, including GT (n = 36 reported) and BSS (n = 29 reported). Of respondents, 75% estimated the risk of antibody formation as "likely" for HLA and 65% for HPA. Formation of HLA antibodies was reported in 5 GT and in 5 BSS-patients, including one child. Fifteen respondents gave preventive HLA-matched platelets in elective setting (75%). Three respondents additionally matched for HPA in GT-patients (15%). Main argument for matched platelet transfusions was preventing alloimmunization to safeguard the effectivity of 'random' donor-platelets in acute settings.

CONCLUSION

Elective HLA-matching for GT and BSS-patients is already conducted by most Dutch (pediatric) hematologists. HPA-matching is mainly applied when HPA-antibodies are formed. Based on the current literature and the survey, recommendations are proposed.

Inherited Platelet Disorders: An Updated Overview

Platelets play a major role in hemostasis as ppwell as in many other physiological and pathological processes. Accordingly, production of about 10¹¹ platelet per day as well as appropriate survival and functions are life essential events. Inherited platelet disorders (IPDs), affecting either platelet count or platelet functions, comprise a heterogenous group of about sixty rare diseases caused by molecular anomalies in many culprit genes. Their clinical relevance is highly variable according to the specific disease and even within the same type, ranging from almost negligible to life-threatening. Mucocutaneous bleeding diathesis (epistaxis, gum bleeding, purpura, menorrhagia), but also multisystemic disorders and/or malignancy comprise the clinical spectrum of IPDs. The early and accurate diagnosis of IPDs and a close patient medical follow-up is of great importance. A genotype-phenotype relationship in many IPDs makes a molecular diagnosis especially relevant to proper clinical management. Genetic diagnosis of IPDs has been greatly facilitated by the introduction of high throughput sequencing (HTS) techniques into mainstream investigation practice in these diseases. However, there are still unsolved ethical concerns on general genetic investigations. Patients should be informed and comprehend the potential implications of their genetic analysis. Unlike the progress in diagnosis, there have been no major advances in the clinical management of IPDs. Educational and preventive measures, few hemostatic drugs, platelet transfusions, thrombopoietin receptor agonists, and in life-threatening IPDs, allogeneic hematopoietic stem cell transplantation are therapeutic possibilities. Gene therapy may be a future option. Regular follow-up by a specialized hematology service with multidisciplinary support especially for syndromic IPDs is mandatory.

Role of Thrombopoietin Receptor Agonists in Inherited Thrombocytopenia

In the last decade, improvements in genetic testing have revolutionized the molecular diagnosis of inherited thrombocytopenias (ITs), increasing the spectrum of knowledge of these rare, complex and heterogeneous disorders. In contrast, the therapeutic management of ITs has not evolved in the same way. Platelet transfusions have been the gold standard treatment for a long time. Thrombopoietin receptor agonists (TPO-RA) were approved for immune thrombocytopenia (ITP) ten years ago and there is evidence for the use of TPO-RA not only in other forms of ITP, but also in ITs. We have reviewed in the literature the existing evidence on the role of TPO-RAs in ITs from 2010 to February 2021. A total of 24 articles have been included, 4 clinical trials, 3 case series and 17 case reports. A total of 126 patients with ITs have received TPO-RA. The main diagnoses were Wiskott–Aldrich syndrome, MYH9-related disorder and ANKRD26-related thrombocytopenia. Most patients were enrolled in clinical trials and were treated for short periods of time with TPO-RA as bridging therapies towards surgical interventions, or other specific approaches, such as hematopoietic stem cell transplantation. Here, we have carried out an updated and comprehensive review about the efficacy and safety of TPO-RA in ITs.

Successful Use of Hematopoietic Stem Cell Transplantation for 2 Pediatric Cases of Glanzmann Thrombasthenia and Review of the Literature

Glanzmann thrombasthenia is a rare platelet disorder characterized by an abnormal integrin receptor on the surface of platelets that results in the failure of platelets to aggregate. Currently, curative therapy is allogeneic hematopoietic stem cell transplantation (HSCT). The authors report 2 patients with Glanzmann thrombasthenia who successfully underwent allogeneic HSCT from unrelated donors, including one using umbilical cord blood stem cells. Although both patients had evidence of engraftment, hematopoietic recovery, and normalization of platelet aggregation, they also experienced several post-transplant complications. Allogeneic HSCT carries a significant risk of morbidity and mortality that should be considered before proceeding with the transplant.

Glanzmann's thrombasthenia with spontaneous upper gastrointestinal bleeding: a case report

Glanzmann’s thrombasthenia (GT) is a rare bleeding disorder inherited in an autosomal recessive manner. The pathogenesis of GT mainly involves structural abnormalities and dysfunction of platelet membrane glycoprotein IIb/IIIa (integrin αIIbβ3). The most common symptoms of GT are various types of bleeding, including recurrent nasal bleeding, mucocutaneous bleeding, unremitting bleeding after injury or operation, and menorrhea in women. Such hemorrhage may be fatal in some patients. GT with spontaneous upper gastrointestinal bleeding is relatively rare. In the present report, we describe a middle-aged man who was hospitalized with spontaneous upper gastrointestinal bleeding. His main symptom was recurrent chronic and intermittent melena. Gastroscopy revealed oozing of blood in the gastric antrum wall. However, no obvious lesions such as erosion or ulceration were found. Upon further inspection, we found that the patient’s platelet aggregation was poor, and flow cytometry assay revealed low expression of platelet membrane integrin αIIbβ3. The patient was eventually diagnosed with GT and exhibited clinical improvement after active treatment.

Allogeneic hematopoietic cell transplantation in an adult patient with Glanzmann thrombasthenia

Glanzmann thrombasthenia is a rare bleeding disorder that can present life‐threatening bleeding. Our patients develop antiplatelet antibodies that become refractory to any pharmacological treatment. Allogeneic hematopoietic stem‐cell transplantation is the only currently curative procedure, but has major risks mainly in adult; indeed, our patient died.