Introduction: Mild bleeding symptoms are commonly encountered in the general population & amongst individuals with platelet disorders. One of the possible causes is due to reduced number of dense granules synthesis in platelets and defective release of its contents. This study was aimed to evaluate platelets mepacrine-labelled dense granules storage and release using flow cytometry in healthy individuals and those presenting with mild bleeding symptoms. Methods: This study was conducted at the National Blood Centre (NBC) and Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM). Thirty- four individuals were recruited as controls (n=24) and patients (n=10). ADP-activated platelets and mepacrine-labelled dense granules was detected using flow cytometry. Results were expressed as mean fluorescent intensity (MFI) of mepacrine in resting and activated platelets; representing dense granules storage and release, respectively. Statistical analysis was considered significant if p ≤0.05. Results: There was a significant difference of mean MFI between resting (1284.3 ± 91.8) and activated platelets (1233.8 ± 107.8) of overall respondents with mean difference of 50.5 (p<0.01). However, there was no significant difference of mean MFI in resting and activated platelets between controls and patients was observed. Conclusion: Results indicated there is no secretion defects in platelet dense granules among patients in comparison with controls. Flow cytometry provides alternative way of dense granule assessment in patients presented with mild bleeding symptoms.
Platelet disorders

Blood Platelets ; Blood Platelet Disorders

OBJECTIVETo analyse the cases of platelet transfusion refractoriness after received HLA-matched unrelated donor hematopoietic stem cell transplantation, to analyze and identify the phenotype and genotype of CD36 in both the patient and stem cell donor, as well as the characteristic of antibody induced platelet transfusion refractoriness, and to analyse the efficacy of matched CD36-deficiency platelets transfusions.

METHODSThe CD36 expression on platelet and monocyte was analyzed by flow cytometry (FCM) in both patient and donor. Polymerase chain reaction sequence-based typing (PCR-SBT) was used to analyze the exons sequence of CD36 and HPA. Fast monoclonal antibody-specific immobilization of platelet antigen (F-MAIPA) and FCM were used to identify platelet antibodies in the patient. Short tandem repeat polymerase chain reaction (STR-PCR) was applied to monitor engraftment evidence. The platelet level was monitored. CD36- deficiency donor's platelets were selected from CD36- deficiency donor blood bank.

RESULTSThe donor was CD36 positive and the patient was typed I CD36 deficiency. The anti-CD36 antibody was identified in patient's serum (after transplantation), while the HLA and HPA-related antibodies were excluded. Sequence analysis of CD36 exon in the patient showed Exon 6 -1G>C(Change in splicing site) homozygote, which was a novel CD36 mutation. STR, HPA and CD36 of the patient (complete chimerism) were conversed to that of donor gene types on day 18 after allo-HSCT. The positive CD36 expression on platelet and monocyte in the patient was observed on day 96 after allo-HSCT. The patient showed the platelet transfusion refractoriness which was significantly improved after platelets transfusions from CD36 deficiency donors.

CONCLUSIONStem cell transplants resulted in anti-CD36 and caused platelet transfusion refractoriness, that was first reported in China. To ensure the efficacy of platelet transfusion, the CD36-deficiency patient should receive CD36 deficiency platelets for transfusion.

Antigens, Human Platelet ; Blood Platelet Disorders ; Blood Platelets ; CD36 Antigens ; China ; Humans ; Platelet Transfusion ; Thrombocytopenia

Gray platelet syndrome (GPS) is one of primary hemostatic disorders with characteristics of moderate bleeding tendency, thrombocytopenia, gray platelet on Wright-Giemsa stained smear and absence of platelet -granule. It is known to be mostly inherited by autosomal dominance but not all. We report a case of gray platelet syndrome diagnosed in a woman with bleeding tendency such as easy bruise and evaluate clinical usefulness of mean platelet component (MPC), mean platelet volume (MPV) and platelet component distribution width (PCDW) using ADVIA 120 (Bayer Diagnostics, NY, USA).
Blood Platelets ; Contusions ; Female ; Gray Platelet Syndrome* ; Hemorrhage ; Hemostatic Disorders ; Humans ; Mean Platelet Volume ; Thrombocytopenia

Dengue/therapy* ; Humans ; Platelet Transfusion ; Vision Disorders/etiology*

BACKGROUND: Mean platelet volume (MPV) increases when platelets are activated, and it is known to increase in migraine patients. The aim of this study is to investigate whether there is a difference in MPV or platelet count between migraine patients with (MA) and without aura (MO).METHODS: Migraine patients were recruited from the out-patient department of a hospital between January 2012 and June 2017. Patients were divided into MA and MO groups. Platelet count and MPV were compared between groups, and the frequency of comorbidities such as ischemic stroke and cardiovascular disease, was investigated in both groups.RESULTS: Of the 123 patients, 46 were classified as MA, and 77 were classified as MO. The MPV of the MA group was significantly higher than that of the MO group (8.92±0.17 fL, 6.32±0.28 fL, respectively) (P=0.034). However, platelet count showed no significant difference between groups. Cardiovascular disease and ischemic stroke incidences were significantly higher in the MA group than in the MO group (ischemic stroke: 15.2%, 7.8%, respectively, P=0.027; cardiovascular disease: 10.9%, 6.5%, respectively, P=0.018).CONCLUSION: Mean platelet volume was significantly greater in the MA group than in the MO group. This may be related to the pathophysiological differences between the two conditions.
Cardiovascular Diseases ; Comorbidity ; Epilepsy ; Humans ; Incidence ; Mean Platelet Volume ; Migraine Disorders ; Migraine with Aura ; Migraine without Aura ; Outpatients ; Platelet Activation ; Platelet Count ; Stroke

OBJECTIVETo study the pathological and clinical characteristics of a patient with spontaneous platelet aggregation of his giant and morphologically abnormal platelets.

METHODSPlatelet size and structure were observed under light microscope and electron microscope. Platelet aggregation was measured turbidometrically. Platelet glycoproteins (GP) were analyzed using flow cytometry. PCR and DNA sequencing were performed to identify the gene abnormality.

RESULTSThe patient had spontaneous platelet aggregation of giant platelets with thickened plasma membrane and increased number of granules in various shapes. Aspirin and ticlopidine did not affect the spontaneous aggregation. The expression of GP I b, GP II b, GP III a and P-selectin in the platelet membrane were in normal range. Results of gene analyses for GP I balpha, GP I bbeta and GPIX were also normal.

CONCLUSIONBoth morphological and functional abnormalities of the platelets from the patient were clearly distinguishable from that of other hereditary giant platelet disorders. It would probably represent a novel platelet disorder which had not been reported to date.

Aspirin ; pharmacology ; Bernard-Soulier Syndrome ; metabolism ; pathology ; Blood Platelet Disorders ; metabolism ; pathology ; Cell Size ; physiology ; Child ; Cytoplasmic Granules ; pathology ; ultrastructure ; Female ; Humans ; Platelet Aggregation ; drug effects ; physiology ; Platelet Aggregation Inhibitors ; pharmacology ; Platelet Membrane Glycoproteins ; genetics ; metabolism ; Ticlopidine ; pharmacology

Essential thrombocythemia in childhood is a rare clonal myeloproliferative disorder in the multipotent stem cell origin and is associated with an increased risk of thrombohemorrhagic complications. The one of diagnostic criteria is a platelet count of more than 600,000/mm3. We diagnosed this disease in 8 year old boy incidentally and treated with hydroxyurea. We report a case of essential thrombocythemia to summarize the current trends in the diagnosis and management with a brief review of related literatures.
Child ; Diagnosis ; Humans ; Hydroxyurea ; Male ; Multipotent Stem Cells ; Myeloproliferative Disorders ; Platelet Count ; Thrombocythemia, Essential*

Sjögren's syndrome is a systemic autoimmune disease characterized by sicca symptoms and extraglandular manifestations. Anemia, leukopenia, thrombocytopenia and lymphoproliferative disorders are well-known extraglandular, hematological complications of Sjögren's syndrome. These hematologic alterations are usually mild and respond well with steroid therapy. We report a case of a 52-year-old female patient who was initially presented with thrombocytopenia. The patient was then diagnosed with primary Sjögren's syndrome and initially treated with steroid. The patient's platelet count was decreased when steroid was tapered. The dose of steroid could be effectively reduced after combined medication with hydroxychloroquine.
Anemia ; Autoimmune Diseases ; Female ; Humans ; Hydroxychloroquine ; Leukopenia ; Lymphoproliferative Disorders ; Middle Aged ; Platelet Count ; Thrombocytopenia*

Aged ; Blood Platelet Disorders ; complications ; therapy ; Coronary Artery Disease ; complications ; therapy ; Humans ; Male ; Stents ; Thrombosis ; etiology