Platelet responses to SFLLRN.
(A) The box plot represents the distribution of SFLLRN concentrations inducing a double wave of aggregation (B). Values ranged from 5 to 19 μM, with a median of 9.75 μM (center horizontal bar). Errors bars indicate 90th and 10th percentiles, respectively. Panel B shows determination of SFLLRN concentration inducing double-wave aggregation profile. At visit 1, the tests were performed with 7, 10, and 15 μM SFLLRN to determine the range of SFLLRN concentrations inducing an irreversible single wave of aggregation. At the second visit, the precise SFLLRN concentration inducing an irreversible double-wave aggregation profile (X value) was determined. (C) Distribution of P-selectin levels, as quantified by flow cytometry on SFLLRN-activated platelets (100 μM) preincubated with eptifibatide to avoid aggregation. The number of P-selectin sites ranged from 6613 to 15 933 sites/platelet (11 223 ± 1934 sites/platelet). Because the response was stable at a 1-week interval (r2 = 50%,P < .01), the mean value of the 2 visits is used for each subject. Box plot displays median value with 25th and 75th percentiles and the bar chart shows 90th and 10th percentiles.
