Cerebrospinal fluid macrophage migration inhibitory factor: a potential predictor of cerebral vasospasm and clinical outcome after aneurysmal subarachnoid hemorrhage

OBJECTIVE In patients with aneurysmal subarachnoid hemorrhage (aSAH), poor outcomes have been shown to be correlated with subsequent cerebral vasospasm (CV) and delayed cerebral ischemia (DCI). The identification of novel biomarkers may aid in the prediction of which patients are vulnerable to developing vasospasm, cerebral ischemia, and neurological deterioration. METHODS In this prospective clinical study at North Shore University Hospital, patients with aSAH or normal pressure hydrocephalus (NPH) with external ventricular drains were enrolled. The concentration of macrophage migration inhibitory factor (MIF) in CSF was assessed for correlation with CV or DCI, the primary outcome measures. RESULTS Twenty-five patients were enrolled in the aSAH group and 9 were enrolled in the NPH group. There was a significant increase in aggregate CSF MIF concentration in patients with aSAH versus those with NPH (24.4 +/- 19.2 vs 2.3 +/- 1.1 ng/ml, p < 0.0002). Incidence of the day of peak MIF concentration significantly correlated with the onset of clinical vasospasm (rho = 0.778, p < 0.0010). MIF concentrations were significantly elevated in patients with versus those without evidence of DCI (18.7 +/- 4.93 vs 8.86 +/- 1.28 ng/ml, respectively, p < 0.0025). There was a significant difference in MIF concentrations between patients with infection versus those without infection (16.43 +/- 4.21 vs 8.5 +/- 1.22 ng/ml, respectively, p < 0.0119). CONCLUSIONS Preliminary evidence from this study suggests that CSF concentrations of MIF are correlated with CV and DCI. These results, however, could be confounded in the presence of clinical infection. A study with a larger patient sample size is necessary to corroborate these findings.