Monocyte chemoattractant protein-1 predicts outcome and vasospasm following aneurysmal subarachnoid hemorrhage

Despite efforts to elucidate both the molecular mechanism and the clinical predictors of vasospasm after aneurysmal subarachnoid hemorrhage (ASAH), its pathogenesis remains unclear. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that has been firmly implicated in the pathophysiology of vasospasm and in neural tissue injury following focal ischemia in both animal models and human studies. The authors hypothesized that MCP-1 would be found in increased concentrations in the blood and cerebrospinal fluid (CSF) of patients with ASAH and would correlate with both outcome and the occurrence of vasospasm.

Seventy-seven patients who presented with ASAH were prospectively enrolled in this study between July 2001 and May 2002. Using an enzyme-linked immunosorbent assay, MCP-1 levels were measured in serum daily and in CSF when available. The mean serum and CSF MCP-1 concentrations were calculated for each patient throughout the entire hospital stay. Neurological outcome was evaluated at discharge or 14 days posthemorrhage using the modified Rankin Scale. Vasospasm was evaluated on angiography.

The serum MCP-1 concentrations correlated with negative outcome such that a 10% increase in concentration predicted a 25% increase in the probability of a poor outcome, whereas the serum MCP-1 levels did not correlate with vasospasm. Concentrations of MCP-1 in the CSF, however, proved to be significantly higher in patients with angiographically demonstrated vasospasm.

These findings suggest a role for MCP-1 in neurological injury and imply that it may act as a biomarker of poor outcome in the serum and of vasospasm in the CSF.