Influence of Platelet Aggregate Formation in Blood Samples on Light Transmission Aggregometry Results

Pitfall of Light Transmission Aggregometry-Based Assessment of Platelet Function in Acute Ischemic Stroke Patients

“…We recently intentionally induced PA formation in citrated blood samples and demonstrated that the removal of large activated platelets during the PRP preparation process led to an MA% reduction associated with decreased platelet counts and MPV in PRP. 10 Similar results obtained in this study targeted for acute ischemic stroke patients further justified our previous results. Large activated platelets included in abundance in patient samples, formed PA, and presumably sank into the buffy coat layer during the PRP separating centrifugation process.…”

“…We recently demonstrated that intentionally induced PA formation in citrated blood samples led to an unexpected reduction in maximum aggregation rate (MA%) measured by LTA because large activated platelets were removed during the LTA measurement process. 10 We speculate that such PA formation may have disturbed the accurate LTAbased assessment of platelet hyperactivity. However, the effect of PA formation on LTA results in patients with acute ischemic stroke has not been verified in the clinical setting.…”

“…For the LTA assay, the platelet-rich plasma (PRP) was separated from the citrated whole blood samples by initial centrifugation (85 £ g for 15 minutes at room temperature), while a subsequent centrifugation (150 £ g for 5 minutes at room temperature) separated out the plateletpoor plasma. 10 In this study, we measured platelet counts and mean platelet volume (MPV) of citrated blood and PRP from 17 patients and 25 healthy subjects.…”

“…PA formation was defined as the detection of a PA fraction on the scattergram of the hematology analyzer during the analysis of citrated-blood sample but not the EDTA-2K sample (Fig 1). 10 During this hematology analysis, PA formed gradually in the citrated blood samples through the automated stirring process. 10 To evaluate the aggregation-prone properties of platelets, the analysis process was repeated up to 4 times until PA appeared in the citrated blood samples, and PA appearance rate within 2 analysis processes and PA counts at the first and second analysis were measured.…”

“…10 During this hematology analysis, PA formed gradually in the citrated blood samples through the automated stirring process. 10 To evaluate the aggregation-prone properties of platelets, the analysis process was repeated up to 4 times until PA appeared in the citrated blood samples, and PA appearance rate within 2 analysis processes and PA counts at the first and second analysis were measured. The PA appearance rates and PA counts were compared between patients and controls.…”