Monocyte count at onset predicts post-stroke outcomes during a 90-day follow up

BACKGROUND: Acute ischemic stroke (AIS) triggers both systemic and neurovascular inflammation, influencing post-stroke recovery. In smokers with AIS inflammation might be further upregulated, increasing ischemia/reperfusion injury. Here, the predictive value of leukocyte and adhesion molecules levels on post-stroke outcomes was investigated. MATERIALS AND METHODS: 89 patients with AIS (n=30 smokers and n=59 non-smokers) were recruited and evaluated 1, 7 and 90 days after the onset to assess stroke severity by the National Institute of Health Stroke Scale (NIHSS) score as well as clinical recovery at 90 day by the modified Rankin Scale (mRS). Lesion volume was assessed by non-contrast computed tomography. Hematological parameters, blood chemistry and soluble adhesion molecules were measured. RESULTS: Smokers experienced a more severe stroke and at a younger age with respect to non-smokers, moreover they had higher circulating levels of monocytes, neutrophils and soluble adhesion molecules. Baseline monocytes positively correlated with stroke severity and disability across all time points in the overall cohort. No correlation was shown between adhesion molecules and post-stroke outcomes. A monocyte count >0.63x109 /L predicted worse stroke severity (defined as NIHSS≥5) at day 90 independently of age, hypertension, thrombolysis and active smoking in the overall cohort. Similarly, a monocyte count >0.64x109 /L predicted poor neurological recovery at day 90 (defined as mRS>2). CONCLUSIONS: Smoker had more severe AIS and higher leukocytes and adhesion molecule levels. In the overall cohort, monocyte count was an independent predictor of worse post-stroke outcome. Although larger trials are needed, monocyte count might be a cheap prognostic parameter in AIS.