Serum macrophage migration inhibitory factor concentrations correlate with prognosis of traumatic brain injury

Background: Macrophage migration inhibitory factor (MIF) is a well-known pro-inflammatory cytokine. Serum MIF concentrations are associated with the severity and prognosis of ischemic stroke. Methods: In this prospective, observational study, white blood cell (WBC) count and serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and MIF among 108 severe traumatic brain injury (TBI) patients and 108 controls were measured. We determined whether serum MIF concentrations are associated with inflammation, severity, in-hospital major adverse events (IMAEs) (i.e., in hospital mortality, acute lung injury, acute traumatic coagulopathy, progressive hemorrhagic injury and posttraumatic cerebral infarction) and long-term clinical outcome (i.e., 6-month functional outcome) after TBI. Results: As compared to the controls, serum CRP, IL-6, TNF-a and MIF concentrations were significantly increased. MIF concentrations correlated with WBC count, CRP, IL-6 and TNF-alpha concentrations and Glasgow coma scale (GCS) scores. MIF in serum was independently associated with IMAEs and long-term clinical outcome. Area under receiver operating characteristic curve of MIF concentrations was similar to GCS scores'. Moreover, MIF concentrations markedly improved the predictive value of GCS scores for 6-month unfavorable outcome. Conclusion: Increased serum MIF concentrations have close relation to inflammation, trauma severity and clinical outcomes, substantializing MIF as a good prognostic biomarker after TBI.