The study, conducted by researchers at UCSF and colleagues at Imperial College, London, explained why many patients experience memory loss or other forms of cognitive dysfunction after surgery or critical illness, a process the researchers traced to a specific inflammatory response in the brain.
Typically short-term, this delirium occurs widely in intensive care units, affecting between 28 and 92 percent of hospitalised patients, depending on their age, health status and type of surgery, the authors said.
It also has been linked to poorer surgical outcomes, as well as an increased risk of mortality, inability to cope and possible permanent dementia.
The new research not only linked that response to an immune protein called tumour necrosis factor (TNF-a), a cytokine, but also identified a likely drug therapy to prevent it, he said.
"Antibody therapies already are widely used against cytokines to prevent or treat inflammation, so we know that these are effective in humans. This study suggests that one day we also might be able to use these therapies as a single, pre-surgical dose to prevent cognitive decline in susceptible patients," said Maze from UCSF.
Previous studies have linked post-operative cognitive decline with the rise in blood levels of interleukin-1 beta (IL-1B), a molecule involved in inflammation. For this study, Maze and his colleagues studied a protein called tumor necrosis factor (TNF-a), which is known to regulate the immune system's inflammatory response before interleukin-1 is produced.
The team gave a single dose of anti-TNF monoclonal antibody to mice using a model of orthopaedic surgery and they found that it successfully acted as a prophylaxis against this disorder.
"This is an important observation, as it demonstrates that cytokines are potential therapeutic targets in a wider range of diseases, not just autoimmune disease and cancer for which they are known targets. Moreover, effective therapeutics already are available, with a known safety profile and modest cost if used short term," said, professor at Imperial college, Marc Feldmann.
The work appears in an upcoming issue of the Proceedings of the National Academy of Sciences.