title: Evaluation of platelet function with the PFA-100 system in patients with congenital defects of platelet secretion.
abstract: The template bleeding time is still the screening test for defects of platelet function, although it is an invasive and poorly reproducible technique. The PFA-100 measures platelet function at high shear. Whole blood is aspirated through a capillary to an aperture of a membrane coated with platelet agonists. The system measures the time required to obtain occlusion of the aperture by a platelet plug (closure time). We measured the closure times in the PFA-100 system and the bleeding time in seven patients with delta-storage pool deficiency, 10 patients with "primary secretion defect" (not due to abnormalities of platelet granules or the arachidonate pathway), and 40 controls. Measurements were repeated I and 4 hours after intravenous infusion of desmopressin in six delta-storage pool deficiency and eight primary secretion defect patients. Baseline bleeding time and closure times with the collagen/epinephrine cartridge were longer in delta-storage pool deficiency and primary secretion defect patients than in controls. In contrast, closure times with the collagen/adenosine diphosphate cartridge were normal in both delta-storage pool deficiency and primary secretion defect patients. Treatment with desmopressin increased the plasma von Willebrand Factor levels, shortened the prolonged bleeding time, shortened the closure times with the collagen/adenosine diphosphate cartridge, and normalized the closure times with the collagen/ epinephrine cartridge. Therefore, the PFA-100 test may be a less invasive alternative to the bleeding time in the diagnosis and therapeutic monitoring of patients with platelet secretion defects. The collagen/epinephrine cartridge is more sensitive than the collagen/adenosine diphosphate cartridge to defects of platelet secretion.
authors.affiliation: Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milano, Italy. marco.cattaneo@unimi.it
authors.forename: M
authors.initials: M
authors.lastname: Cattaneo
authors.forename: A
authors.initials: A
authors.lastname: Lecchi
authors.forename: B
authors.initials: B
authors.lastname: Agati
authors.forename: R
authors.initials: R
authors.lastname: Lombardi
authors.forename: M L
authors.initials: ML
authors.lastname: Zighetti
mesh_terms: D000328:Adult; D001760:Bleeding Time / Q000295:instrumentation*; D001791:Blood Platelet Disorders / Q000097:blood* / Q000151:congenital; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000295:instrumentation / Q000379:methods; D008875:Middle Aged; D010973:Platelet Adhesiveness / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D010979:Platelet Function Tests / Q000295:instrumentation*; D010981:Platelet Storage Pool Deficiency / Q000097:blood