Association of Blood Biomarkers Cell-Free DNA (cfDNA) and High-Sensitivity C-Reactive Protein (hsCRP) With Stroke Severity and Outcome: A Prospective Observational Study

Background Stroke remains a leading cause of disability and mortality worldwide, with a rising incidence in India. Early identification of patients at risk for severe stroke and poor outcomes is crucial for timely intervention. Despite advancements, current diagnostic tools lack sufficient sensitivity and specificity for early prognostic stratification. Emerging evidence highlights cell-free DNA (cfDNA), a marker of cellular injury, and high-sensitivity C-reactive protein (hsCRP), an inflammatory marker, as promising candidates. These biomarkers were selected over others due to their robust association with tissue damage and inflammation, two pivotal mechanisms in stroke pathophysiology. This study aimed to assess the prognostic value of cfDNA and hsCRP in acute ischemic stroke patients and their association with stroke severity and outcomes. Methods This prospective observational study included 54 acute ischemic stroke patients admitted within 12 hours of symptom onset. Clinical assessments were performed using the National Institutes of Health Stroke Scale (NIHSS) at admission and the modified Rankin Scale (mRS) at three months to evaluate stroke severity and outcomes. Blood samples were collected to measure cfDNA and hsCRP levels. Correlation analyses were conducted to evaluate the association between biomarkers and stroke severity (NIHSS) and outcomes (mRS). Receiver operating characteristic (ROC) curve analysis determined optimal biomarker thresholds and logistic regression analysis identified independent predictors of poor neurological outcomes (mRS ≥ 3). Results The median age of the cohort was 61 years, with a mean of 61.6 ± 16.1 years, and 68.5% were male. cfDNA showed significant correlations with NIHSS (ρ = 0.222, p = 0.040) and mRS (ρ = 0.396, p = 0.002), while hsCRP correlated with NIHSS (ρ = 0.354, p = 0.001) and mRS (ρ = 0.328, p = 0.010). ROC analysis identified cfDNA (>10,000 kilogenome equivalents/L) and hsCRP (>6 mg/L) as predictive thresholds for severe stroke and poor outcomes, with area under the curve (AUC) values of 0.79 and 0.71, respectively. Logistic regression indicated age > 60 years (OR 1.45, p = 0.041), cfDNA > 10,000 (OR 3.12, p = 0.027), hsCRP > 6 mg/L (OR 2.75, p = 0.039), and higher NIHSS (OR 1.23, p = 0.042) as significant predictors of poor neurological outcomes. These thresholds can guide early interventions, and the modest correlation coefficients reflect the multifactorial nature of stroke. This study uniquely proposes predictive thresholds for cfDNA and hsCRP in an Indian cohort, adding to the existing evidence on their clinical utility. Conclusion The study demonstrates that elevated cfDNA and hsCRP levels are significantly associated with stroke severity and poor outcomes in acute ischemic stroke patients. These biomarkers, alongside age and NIHSS score at admission, may serve as valuable tools in predicting prognosis and guiding early therapeutic interventions in stroke management. Future research should focus on evaluating the cost-effectiveness, feasibility, and integration of these biomarkers into routine clinical practice to optimize stroke care.