Early Elevation of Serum Tumor Necrosis Factor-α is Associated with Poor Outcome in Subarachnoid Hemorrhage

OBJECTIVE: Subarachnoid hemorrhage (SAH) is associated with inflammation that may mediate poor outcome in SAH. We hypothesize that elevated serum tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) are associated with vasospasm and poor outcome in SAH. METHODS: In 52 consecutive SAH subjects, we compared TNF-α and IL-6 levels on post-SAH days 0 to 1, 2 to 3, 4 to 5, 6 to 8, and 10 to 14 with respect to vasospasm and to poor outcome at 3 and 6 months. Vasospasm was defined as more than 50% reduction in vessel caliber on angiography. Poor outcome was defined as modified Rankin score greater than 2. RESULTS: Elevated TNF-α on post-SAH days 2 to 3 was associated with poor 3-month outcome (P = 0.0004). Global elevation of TNF-α over time (post-SAH days 0-14) was independently associated with poor 3-month outcome after adjusting for Hunt-and-Hess grade and age (P = 0.02). Neither cross-sectional nor IL-6 levels over time were associated with outcome. Neither TNF-α nor IL-6 levels were associated with vasospasm. CONCLUSIONS: Elevation in serum TNF-α on post-SAH days 2 to 3 and global elevation of TNF-α over time are associated with poor outcome but not with angiographic vasospasm in this small cohort. Future studies are needed to define the role of TNF-α in SAH-related brain injury and its potential as a SAH outcome biomarker.