The specific ex vivo released cytokine profile is associated with ischemic stroke outcome and improves its prediction

Background Inflammation is associated with poor outcome after stroke. A relationship between ex vivo cytokine synthesis and stroke outcome remains unclear. We explored an association between ex vivo cytokine release, circulating interleukin (IL)-6 as a marker of systemic inflammation, and stroke prognosis. We assessed the utility of ex vivo synthesized cytokines for predicting stroke outcome. Methods We collected blood from 248 ischemic stroke patients and stimulated it ex vivo with lipopolysaccharide. We measured concentration of synthesized cytokines (TNF alpha, IP-10, IL-1 beta, IL-6, IL-8, IL-10, and IL-12) and plasma IL-6. We assessed functional outcome 3 months after stroke using the modified Rankin Scale. To assess the prognostic ability of cytokines, we applied multivariate logistic regression, cluster analysis, and construction of multimarker score. Results Decreased release of IP-10, TNF alpha, IL-1 beta, and IL-12; increased release of IL-10 and IL-8; and higher plasma IL-6 level were associated with poor outcome. Cluster analysis identified three groups of patients with distinct cytokine profiles. The group with the worst outcome demonstrated high synthesis of IL-10, IL-8, IL-1 beta, and IL-6 and low synthesis of IL-12, IP-10, and TNF alpha accompanied by high circulating IL-6 level. The group with the best prognosis showed high synthesis of TNF alpha, IP-10, IL-12, IL-1 beta, and IL-6; low synthesis of IL-10 and IL-8; and low plasma IL-6. Patients with intermediate outcome had low synthesis of all cytokines accompanied by low circulating IL-6. We constructed a multimarker score composed of ex vivo released IL-12, IL-10, TNF alpha, and plasma IL-6. Addition of this score to clinical variables led to significant increase in c-statistic (0.81 vs 0.73, p = 0.02) and net reclassification improvement. Conclusion The decreased ex vivo release of pro-inflammatory cytokines and increased release of IL-10 and IL-8 are related to poor outcome after stroke. Cytokine-based multimarker score adds prognostic value to clinical model for predicting stroke outcome.