Summary
The white blood cell count and mean platelet volume determined shortly after the symptom
onset are known as independent predictors for clinical outcome after stroke. In the
present study we sought to evaluate the prognostic value of platelet-derived inflammatory
biomarkers measured prospectively after an ischaemic event. Using five-colour flow
cytometry, the platelet surface expression of CD40L, CD62P and subpopulations of leukocyte-platelet
aggregates were assessed in 93 stroke patients on the first (V0), 10th (V1) and 90th (V2) day after stroke, and once in 65 disease controls. The clinical outcome was evaluated
using the Scandinavian Stroke Scale (SSS) and modified Rankin Scale (mRS) at the same
time points as blood sampling and 24 months after the event. Patients with either
CD40L surface expression or the percentage of monocyte-platelet aggregates (M-plt)
in the third tertile (T3) at V0 had a significantly lower score on the SSS at V1. Patients with the percentage M-plt at V0 higher than the median value of M-plt in controls were at increased risk of SSS <
40 at V1 (odds ratio: 2.6; 95% confidence interval [CI]: 1.4 – 8.7; p=0.006). Patients with
the percentage of M-plt in T3 at V0 showed progressive decline in survival (hazard ratio [HR]: 1.6; 95% CI: 1.1–1.9;
p=0.02) and a significantly higher number of recurrent vascular events (HR: 2.64;
95% CI: 1.3–3.2; p=0.02) when compared to the first tertile. In conclusion, increased
levels of M-plt could be a predictive marker for both early outcome and long-term
prognosis while increased CD40L was correlated with worse clinical outcome.
The preliminary results of this study were presented in part during a poster session
at the 62nd Annual Meeting of the American Academy of Neurology in Toronto, 7–17 April 2010.
Keywords
Leukocyte-platelet aggregates - CD40L - stroke - prognostic factors