Reduced CD151 expression in neonates. Characteristics of preterm neonates <32 weeks GA, 32 to 36 weeks GA, >36 weeks GA (t), infants 28d-2a, children 2 to 13a, and adults >13a are displayed. (A) Representative images and (B) quantification of the different spreading phases of fixed term neonate and control platelets 45 minutes after differential interference contrast imaging (Zeiss Axiovert 200 inverted microscope [100×/1.4 oil objective]). (C-D) CD9 and (E-F) CD151 expression were assessed in whole blood using flow cytometry. (D) CD9 expression vs forward scatter (FSC) (F) PAC-1 binding after ADP (5 μM) stimulation vs CD151 expression. All graphs show the median ± 95% confidence interval. Differences were analyzed using Kruskal-Wallis-test. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001. ns, nonsignificant.