Increase in soluble CD95L during subacute phases after human spinal cord injury: a potential therapeutic target

Study design: A pilot study measuring the levels of serum-soluble CD95 ligand (CD95L) in eight spinal cord-injured patients. Objectives: To determine the soluble concentration of CD95L in spinal cord injury (SCI) patients after trauma. Methods: We collected blood samples from eight patients with acute traumatic SCI. Soluble CD95L serum levels were determined using an enzyme-linked immunosorbent assay. American Spinal Injury Association (ASIA) was determined according to ASIA classification. The patients were monitored, and venous blood was drawn after arrival at the hospital on the 1st and 3rd day and during the 1st, 2nd, 4th, 8th and 12th weeks after trauma. Results: The average patient age was 48.1 years (18-86 years). Three patients were paraplegic (two incomplete, one complete), five were quadriplegic (one complete, four incomplete). The serum concentration of soluble CD95L (sCD95L) decreased during the 1st week (41 ng l(-1)) and increased after the 2nd week in all eight patients. It peaked during the 4th week (68.5 ng l(-1)) and reached a plateau during the 12th week (76.2 ng l(-1)). There are many possible explanations for not being able to detect a statistical significance, one of course being the small sample size. Conclusion: Promising results for anti-CD95L therapy have already been documented in lab studies with rodents. Anti-CD95L blocks the pro-apoptotic and proinflammatory activity of membrane-bound CD95L during the acute phase of SCI. We observed that sCD95L levels are elevated during the subacute and intermediate phases of SCI. It would be of great interest to study a larger group of patients to determine whether higher sCD95 levels are correlated with improved or impaired neurological outcome or with increasing levels of autoimmune components in peripheral blood. Spinal Cord (2013) 51, 183-187; doi:10.1038/sc.2012.139; published online 27 November 2012