Impaired platelet function and peripartum bleeding in women with Gaucher disease

Brain-Derived Neurotrophic Factor (BDNF) Is Associated with Platelet Activity and Bleeding Tendency in Patients with Gaucher Disease

Bleeding tendency, a prominent feature of patients with Gaucher disease (GD), is associated with abnormal platelet function. Brain-derived neurotrophic factor (BDNF) is a protein with neuroprotective potential stored in alpha granules of circulating platelets. Here we studied BDNF levels in 50 patients with type I GD (GD1) and their correlation with platelet activity and bleeding tendency. Flow cytometry was used to test unstimulated and stimulated measurement of platelet surface-activated expression of αIIbβ3 integrin, P-selectin and lysosomal-associated membrane protein (LAMP3/CD63). Serum and plasma BDNF levels were quantified using ELISA. The bleeding history was recorded by a bleeding questionnaire. Serum BDNF levels were positively correlated with platelet count and moderately correlated with unstimulated and stimulated platelet P-selectin expression. Patients with more than one bleeding manifestation were shown to have lower serum BDNF levels, albeit similar platelet count. Plasma BDNF levels were significantly elevated in splenectomized patients and showed a moderate positive correlation with stimulated platelet CD63 expression. These observations demonstrate the first association between BDNF levels in the peripheral blood with platelet dysfunction and increased bleeding manifestation. The role of measuring serum BDNF for assessing platelet alpha degranulation defects and bleeding risk in patients with GD and the general population needs further study.

Platelet Activation and Reactivity in a Large Cohort of Patients with Gaucher Disease

OBJECTIVES

 Patients with Gaucher disease (GD) are at increased risk of bleeding and have varying degrees of thrombocytopenia, making the analysis of platelet function difficult. This study aimed to provide a clinically relevant quantitative assessment of platelet function and determine its relationship with bleeding and GD-related data.

METHODS

 Unstimulated and stimulated platelet function was measured by whole blood flow cytometry of platelet surface-activated αIIbβ3 integrin (detected with monoclonal antibody PAC1), P-selectin (CD62P), and lysosomal-associated membrane protein (LAMP3/CD63) in 149 GD patients.

RESULTS

 GD patients had a higher level of unstimulated CD63 expression than healthy subjects, which was mildly correlated with glucosylsphingosine (lyso-Gb1) levels (r = 0.17, p-value = 0.042). Splenectomized GD patients had a higher level of unstimulated αIIbβ3 integrin and P-selectin expression. Reduced platelet reactivity (-2 standard deviation of reference range) was found in 79 (53%, 95% confidence interval [CI]: 44-61%) patients, of whom 10 (6.7%, 95% CI: 3.3-12%) had more severe platelet dysfunction. In a multivariate model, only lyso-Gb1 levels were associated with the more severe platelet dysfunction. Fifty-four (49%) of 128 adult patients who completed the bleeding tendency questionnaire reported positive bleeding history. In a multivariate logistic model, older age (odds ratio [OR]: 1.05, 95% CI: 1.01-1.1) and low P-selectin reactivity (OR: 2.03, 95% CI: 1.25-3.35) were associated with more than one bleeding manifestation.

CONCLUSION

 Flow cytometry enables the study of platelet function in thrombocytopenic GD patients. A platelet degranulation defect, but not αIIbβ3 integrin activation defect, is associated with clinical bleeding. In vivo increased CD63 expression may be related to GD-related inflammation.

Risk of postpartum hemorrhage in multiparous women with Gaucher disease: A call for reconsidering enzyme replacement therapy in all pregnant patients

For the last three decades, enzyme replacement therapy (ERT) for Gaucher disease (GD) has been available. We aimed to evaluate the effect of ERT on the pregnancy and obstetric outcome in a unique group of multiparous women with type 1 GD (GD1) who had pregnancies with and without ERT. The Gaucher Unit database (1987-2019) was searched for multiparous women who had pregnancies before and after the institution of ERT. Data were collected from the clinic files and study-specific questionnaires. Descriptive, correlation analysis and generalized estimating equations (GEE) were used to study the effect of ERT and confounding variables on study outcomes. We identified 19 women with 105 pregnancies, among which 26 (24.7%) terminated in first-trimester miscarriage. The risk for miscarriage was associated with the severity of GD1 genotype and phenotype, but not with ERT usage. Early postpartum hemorrhage (PPH) was reported in 16 (84%) women after 25 deliveries (31.6%, 95% CI 21.6%-43.1%). The risks of early PPH and red blood cell (RBC) transfusions were significantly lower when ERT was used during pregnancy, OR (95% CI) 0.13 (0.03-0.54) and 0.27 (0.08-0.94), respectively, compared to pregnancies without the use of ERT. Enzyme replacement therapy during pregnancy is risk reducing for early PPH and RBC transfusions in women with GD1. We suggest considering ERT for the benefit of all pregnant women with GD1, including mild GD1.

Thromboelastography Before Epidural Placement in a Thrombocytopenic Parturient With Gaucher Disease Treated With Imiglucerase: A Case Report

Gaucher disease is a common inborn error of metabolism leading to widespread chronic inflammation and often thrombocytopenia. Here we discuss assessment of coagulation in a parturient with Gaucher disease treated with imiglucerase, who presented with thrombocytopenia and requested epidural analgesia for planned vaginal delivery. We used thromboelastography to determine the safety of placing an epidural catheter and to plan for potential peripartum bleeding. The patient had a normal coagulation profile by thromboelastography and had uncomplicated epidural analgesia for a successful spontaneous vaginal delivery.

Thromboelastography as a Surrogate Marker of Perisurgical Hemostasis in Gaucher Disease

Thromboelastography (TEG) has long been available for routine monitoring of perisurgical and postpartum hemostasis, especially at point of care. The purpose of this study is to retrospectively compare TEG parameters to concomitant standard clotting test results in an unselected cohort of patients with Gaucher disease to ascertain whether TEG values are specific and sensitive enough to substitute for classic coagulation tests for decision making. This remains a cogent concern because of high incidence of thrombocytopenia in patients with Gaucher disease. Thromboelastography values were compared to concomitant platelet counts, partial thromboplastin time, international normalization ratio, and plasma fibrinogen. Demographic characteristics were collected from patients’ files. There were 22 patients with Gaucher disease (2 children; 12.5%) for whom there were 24 TEG results at the same time as classic coagulation test results and 30% performed platelet function tests. The current study shows linear and/or monotonic relationships between platelet counts and several TEG values that were significant over a range of platelet counts including severe thrombocytopenia. The fibrinogen component, correlating only with the rate of clot lysis, played a lesser role. Based on these preliminary results albeit in a small cohort with only 1 case of hemorrhage, there is putative support for the intention to treat patients with Gaucher disease based on TEG results using the same TEG protocol as for other patients undergoing comparable procedures in our institution.

Complex haemostatic abnormalities as a cause of bleeding after neurosurgery in a patient with Gaucher disease

We report a treatment-naïve patient with Gaucher disease (GD) who experienced repeated bleeding after three neurosurgeries for a brain tumour, identified as an oligoastrocytoma. The patient had normal values on basic haemostatic tests: prothrombin time, 75-105%; activated partial thromboplastin time, 30.3-34 s; and mild thrombocytopaenia, 96-115 × 10(9 )cells/l. However, additional tests showed mild von Willebrand factor (vWF) deficiency (vWF antigen, 56%; vWF ristocetin cofactor, 49%; factor VIII [FVIII], 54%) and abnormal collagen-mediated platelet aggregation (0.45-0.55). Bleeding control was achieved after vWF/FVIII concentrate and platelet transfusions. This case raises questions about the safe platelet count and basic haemostatic tests for assessing bleeding risk in patients with GD prior to surgery. In patients with GD, a minimum haemostatic evaluation should include platelet count and basic haemostatic tests such as fibrinogen, prothrombin time, activated partial thromboplastin time as well as platelet function tests and assessing vWF and FVIII levels. Specific coagulation factors or platelet function deficiencies should be corrected with factor concentrates or platelet transfusions.

Imiglucerase in the treatment of Gaucher disease: a history and perspective

The scientific and therapeutic development of imiglucerase (Cerezyme(®)) by the Genzyme Corporation is a paradigm case for a critical examination of current trends in biotechnology. In this article the authors argue that contemporary interest in treatments for rare diseases by major pharmaceutical companies stems in large part from an exception among rarities: the astonishing commercial success of Cerezyme. The fortunes of the Genzyme Corporation, latterly acquired by global giant Sanofi SA, were founded on the evolution of a blockbuster therapy for a single but, as it turns out, propitious ultra-orphan disorder: Gaucher disease.

Haemostatic abnormalities in treatment-naïve patients with Type 1 Gaucher's disease

There is a paucity of data on the effects of enzyme replacement therapy (ERT) on the coagulation abnormalities and platelet function of patients with Gaucher's disease (GDPs) and much of this data are controversial. This study investigates the haemostatic parameters in treatment-naïve GDPs and the effects of ERT. 31 Serbian treatment-naïve type 1 GDPs (M/F 17/14; median age 49 years, splenectomized 9/31) were studied. The complete blood count, prothrombin time (PT), activated partial tromboplastin time (aPTT) and coagulation factors were measured using the standard methods. Platelet aggregation was assessed with a whole-blood aggregometer. Splenic volumes were assessed using computer tomography. Twenty-one patients were treated with ERT (Imiglucerase). The haemostatic parameters were assessed after 6, 12 and 24 months (ERT(6, 12, 24)). Initially bleeding episodes were registered in 10/31 GDPs. Median platelet count was 108 × 10(9)/L; 22/31 GDPs were thrombocytopenic. The PT and aPTT values were abnormal in 16/31 and 13/31 GDPs, respectively. Platelet aggregation abnormalities were recorded in 19/31GDPs. Median platelet aggregation was reduced in response to adenosine-diphosphate 5 µmol/L (ADP(5) 0.46) and collagen 5 µmol/L (Col(5) 0.47). Splenic volume inversely correlated with the platelet count and a reduced response to arachidonic acid (AA), Col(5) and ADP(5) (p < 0.05). The splenectomized GDPs had a significantly lower platelet aggregation to Col(10) (p < 0.05). Bleeding GDPs had a significantly lower platelet count, higher chitotriosidase levels and a greater splenic volume compared to non-bleeding patients (p < 0.01). ERT: The number of bleeding GDPs had significantly decreased by ERT(6) (1/10; p < 0.01). The platelet count had significantly increased by ERT(6) (ERT(6) 180 × 10(9)/L, p < 0.01). The PT increased significantly from ERT(0) to ERT(24) (PT(0) 65%, PT(24) 81%; p < 0.05). The von Willebrand factor had increased significantly by ERT(6) and ERT(24) (ERT(0) 56%, ERT(6) 70%, ERT(12) 70%, ERT(24) 86%; p < 0.01). The number of GDPs with abnormal platelet aggregation had decreased significantly by ERT(6) (10/19; p < 0.05). Platelet aggregation on ADP(10) and AA significantly increased by ERT(6) (ADP(10): ERT(0) 0.75, ERT(6) 0.8 p < 0.01; AA: ERT(0) 0.7, ERT(6) 0.8 p < 0.05). In conclusion, platelet dysfunction and coagulation abnormalities were found in a considerable number of our GDPs. The absence of severe bleeding episodes suggests that the haemostatic system is sufficiently balanced and therefore the exact mechanism of the etiology of these abnormalities need to be fully clarified. ERT resulted in the cessation of bleeding and marked increase in platelet count, PT, vWF and platelet aggregation.