Abstract
We compared the sensitivity and specificity of two methods to detect platelet activation, i.e., the spontaneous platelet aggregation of small aggregates (SPA) and the flow cytometric method, and determined the correlation between these two methods. Thirty-five patients with chronic cerebral infarction (CCI) and 19 age-matched control subjects were enrolled in this study. Platelet activation was first determined by SPA using laser light scattering. Platelet activation was also measured by flow cytometry and two activation-dependent monoclonal antibodies (MoAbs), a MoAb against CD62P (MoAb-CD62P) and a MoAb against the platelet fibrinogen receptor (PAC-1). When cut off points were set at the mean+2SD (standard deviation) of the control subjects, the SPA, MoAb-CD62P and PAC-1 methods demonstrated sensitivity of 37.1%, 60% and 60%, and specificity of 100%, 100% and 94%, respectively. When ROC (Receiver Operating Characteristics) curves were drawn based on these methods, however, the differences in AUC were not statistically significant. There was a statistically significant correlation between the SPA value and the CD62P positive rate, and also between the SPA value and the PAC-1 positive rate. The PAC-1 and the MoAb-CD62P methods were more sensitive than the SPA method in detecting platelet activation in CCI patients.
