Publication Only: Platelets disorders
Hereditary platelet function disorders constitute a rare cause of symptomatic bleeding. These disorders are heterogeneous in clinical expression and also in laboratory evaluation.The accurate measurement of the platelet function and the identification of a congenital platelet disorder is complex, includes different assays and the repetition of testing.
371 patients (241 women/ 130 men) from the region of Macedonia and Thrace, Northern Greece, were referred for platelet function evaluation due to personal and/ or family bleeding tendency. They all manifested symptoms of excessive mucocutaneous bleeding such as bruising or excessive bleeding following surgical or dental procedures. Patients with prolongation of PT, aPTT and TT were excluded and they were investigated for coagulation factors deficiencies. All patients were tested negative for Von Willebrand's Disease.
The platelet function investigation consisted of the 1. the platelet number and size using an automated cell counter 2. blood film report for platelet size and white cell inclusions 3. aggregation testing in platelet rich plasma with light transmission aggregometry (LTG) by the use of 5 agonists (arachidonic acid, ADP, adrenaline, collagen, ristocetin). No medications and strict dietary conditions were given prior testing. In cases of abnormal responses the test was repeated after 1 month and it was considered as abnormal when the deficit sustained on repetition. A clinical assessment of bleeding history (BAT SCORE) and family history for potential inheritance pattern was done.
A percentage of 55.4% (223 patients) had abnormal LTG and were negative for coagulation factors deficiencies and thrombopenia. 53,8% (120 patients) of them were women, since these disorders are more commonly diagnosed in women because of the menstrual cycle and the haemostatic challenge of childbirths. The hemorrhagic history of the patients was serious menhorhagia (female), bruises and the excessive bleeding following surgical or dental procedures (male and female) patients. 110 patients were diagnosed as disorders of platelet secretion and signal transduction (WARD), 51 as aspirin like defect (ALD), 27 had abnormal aggregation to collagen, 8 abnormal aggregation to several agonists, 2 as thrombasthenia Glanzmann and 2 cases of MYH9 related disorders. Abnormal platelet morphology was found in 58 out of the 223 patients. 30 family members from 14 families that were investigated and detected with ALD (7 families), WARD (3 families) and collagen receptor defect (3 families) and MYH9 related (1 family).
Thought platelet disorders are mostly undiagnosed causes of symptomatic bleeding a remarkable percentage was found in our patients. The exact prevalence in the general population is not yet established. Aggregation tests give a lot of information about various platelet disorders as seen in our patients and seem to remain the gold standard in the evaluation of platelet disorders. Families' studies are reasonable in order to detect such abnormalities.