Effect of IL-6 and hsCRP Serum Levels on Functional Prognosis in Stroke Patients Undergoing IV-Thrombolysis: Retrospective Analysis

Abstract

Purpose: We evaluated the relationship between pretreatment IL-6 and hsCRP levels, symptom severity and functional outcome of patients with acute ischemic stroke (AIS) treated with IV-thrombolysis.

Patients and methods: IL-6 and hsCRP samples were obtained from 83 consecutively treated Caucasian patients with AIS prior to initiation of IV-thrombolysis. Severity of stroke symptoms was assessed using the National Institutes of Health Stroke Scale (NIHSS), whereas functional outcome was assessed with modified Rankin Scale (mRS). The commercially available sets of enzymatic immune tests were used to estimate the concentrations of inflammatory markers in serum.

Results: Medians of IL-6 serum concentrations prior to IV-thrombolysis were lower in patients with favorable (mRS 0-2 pts) functional outcome than in those with unfavorable (mRS 3-6 pts) functional outcome, both at hospital dismission (5.92: 2.30-7.71 vs 9.46: 3.79-17.29 pg/mL; p<0.01) and on the ninetieth day from stroke onset (5.87: 2.30-10.58 vs 10.9: 5.94-17.28 pg/mL; p<0.01). There were no existing differences regarding hsCRP levels between groups (2.49: 0.11-9.82 vs 4.44: 0.32-9.87 mg/dL; p=0.30 and 2.57: 0.11-2.57 vs 2.83: 0.32-9.32 mg/dL; p=0.75, respectively). Patients with lacunar strokes were characterized by lower median of IL-6 (5.96: 2.87-13.0% vs 7.29: 2.30-17.28; p=<0.02) and hsCRP (2.25: 0.11-9.82 vs 4.84: 0.35-9.87; p=0.01) than those with nonlacunar infarctions. Multivariate analysis showed an impact of IL-6 on mRS measured on hospital dismission and after three months, regardless of their initial NIHSS, presence of hemorrhagic transformation and type 2 diabetes. No impact of hsCRP, lacunar etiology and patients' age on functional outcome existed.

Conclusion: Regardless of the stroke etiology, pretreatment of IL-6, but not of hsCRP levels, may help to predict functional outcome after IV-thrombolysis independently of symptom severity and stroke complications.

Keywords: inflammatory markers; ischemic stroke; old age diseases; thrombolysis.

Figure 1

Pretreatment IL-6 serum concentrations in patients with and without favorable functional outcome on dismission (A) and on the ninetieth day (B) from the stroke onset.

Figure 2

ROC curves showing sensitivity and specificity of IL-6 measurements for good functional outcome: (A) on dismission (cut-off point ≤7.06 pg/mL, sensitivity 90%, specificity 78.9%), (B) on the ninetieth day from the stroke onset (cut-off point ≤6.51 pg/mL, sensitivity 74.4%, specificity 87.5%).