Showing papers on "Blood Platelet Disorders published in 2011"

Diagnostic Usefulness of a Lumi-Aggregometer Adenosine Triphosphate Release Assay for the Assessment of Platelet Function Disorders

Abstract: Platelet dense granule release assays are recommended for diagnosing platelet function disorders and are commonly performed by Lumi-Aggregometer (Chrono-Log, Havertown, PA) assays of adenosine triphosphate (ATP) release. We conducted a prospective cohort study of people tested for ATP release defects to assess bleeding symptoms. Reduced release, with 1 or more agonists, was more common among patients with bleeding disorders than among healthy control subjects ( P < .001). The respective likelihood (odds ratio [95% confidence interval]) of a bleeding disorder or an inherited platelet function disorder were high when release was reduced with 1 or more agonists (17 [6–46]; 128 [30–545]), even if aggregation was normal (12 [4–34]; 105 [20–565]). ATP release had high specificity and moderate sensitivity for inherited platelet function disorders, with most abnormalities detected by the combination of 6 μmol/L epinephrine, 5.0 μg/mL collagen, and 1 μmol/L U46619. Platelet ATP release assays are useful for evaluating common bleeding disorders, regardless of aggregation findings.

Inherited platelet disorders: a clinical approach to diagnosis and management.

Abstract: Inherited platelet disorders encompass a heterogeneous group of bleeding disorders where a variety of molecular defects can affect platelet number, function or both. The defects involve deficiencies or dysfunction of platelet receptors, signaling pathways, cytoskeletal proteins, granule contents and abnormalities in procoagulant activity. These disorders can be difficult to distinguish clinically as they present with the common symptom of mucocutaneous bleeding. Inherited thrombocytopenia needs to be considered in all patients suspected of having primary immune thrombocytopenia, where platelets may also have functional defects. After a careful history and physical examination, initial investigations include a complete blood count with a peripheral smear, followed by appropriate specific investigations that often require specialized referral centers. This article is a summary of the current data on clinical presentation, pathogenesis, diagnosis and management of inherited platelet disorders.

Sticky platelet syndrome in patients with uninduced venous thrombosis.

Abstract: Objective: Sticky platelet syndrome (SPS) is a common autosomal dominant inherited platelet disorder. SPS is characterized by platelet hyperreactivity and is associated with arterial and venous thrombosis. The aim of this study was to determine the role of SPS in patients with uninduced venous thrombosis. Material and Methods: The study included 28 patients (15 male and 13 female) with uninduced venous thrombosis. SPS was defined according to Mammen’s aggregation method, which is described in detail elsewhere. Results: According to the defined ranges for platelet hyperreactivity, 3 (50%) patients, 2 (33%), and 1 (17%) (n =6 [21%]) with a confirmed diagnosis were classified as type II, I, and III SPS, respectively. In 1 patient SPS was the only hereditary abnormality noted. The other 5 patients carried other inherited coagulation defects, in addition to SPS. Conclusion: The present findings indicate that the prevalence of SPS was 21% in the patients with uninduced venous thrombosis. We therefore suggest that SPS should be considered in the differential diagnosis of such cases. Conflict of interest:None declared.

Dysmegakaryopoiesis, a clue for an early diagnosis of familial platelet disorder with propensity to acute myeloid leukemia in case of unexplained inherited thrombocytopenia associated with normal-sized platelets.

Abstract: We report dysmegakaryopoiesis in a case of familial platelet disorder with predisposition to acute myeloid leukemia (familial platelet disorder/acute myeloid leukemia phenotype Mendelian Inheritance in Man number 601 399). Slight reduction of the number of megakaryocytes with high nucleocytoplasmic ratio, strongly basophilic cytoplasm and poorly lobulated nuclei are suggestive of megakaryocytic dysplasia.

I need to pay more attention to mild haemophilia patients.

Abstract: Here s my experience with dropping the ball . A 15-year-old male patient was referred with persistent bleeding after the removal of third molars. His slightly prolonged activated partial thromboplastin time turns out to be a non-specific anticoagulant. The factor assays were normal including a factor VIII (FVIII) of 70% and the Von Willebrand studies normal. The platelet aggregation studies showed minor non-specific abnormalities. DDAVP and Aminocaproic Acid helped, but not as much as expected. Finally, with time, local haemostatic measures, a dose of Recombinant factor VIIa, and a platelet transfusion, the bleeding stopped. I was not very sure whether the diagnosis of a non-specific platelet disorder was correct. Still, phone calls and letters were unable to get the patient and his family to return for further evaluation. Four years later, he returned with a week-old basketball-related hamstring bleed. Repeat factor assays were normal including a FVIII, again in the 70% range. It appeared that the bleeding had stopped, but his range of motion was restricted and it was still quite painful. As our physiotherapist monitored and guided his recovery, three subsequent FVIII assays fell into the mid twenties. Von Willebrand studies were normal. Lessons learnt: FVIII levels can go up with pain and stress. Patients and families with mild bleeding disorders do not like being patients. Even with acceptance, mild patients are not seasoned by frequent bleeding experiences as to what to do after trauma. While our daily work remains consumed with the inhibitor munchkins , I learned the importance of keeping track of a patient with a problematic diagnostic label, and particularly the need to check FVIII levels after the smoke clears .