Patients with inflammatory diseases or infections often also suffer from fatigue and exhaustion, insomnia and even depression. What causes these symptoms now, researchers from the Friedrich-Alexander University Erlangen-Nuremberg and the University Hospital Erlangen. They identified a chemical messenger that controls communication between the immune system and brain crucial.

The researchers studied patients with rheumatoid arthritis, as well as mice that show due to a genetic defect, a similar disease. Both people and mice suffering from inflamed joints and severe pain. There are also many cases in tiredness and fatigue, insomnia and depression. It was known previously that these symptoms occur in the central nervous system. However, as affect the immune system and inflammation in the joints, the nervous system, could not explain the science to date.

Using functional magnetic resonance imaging, they examined the brains of anesthetized mice. The team led by Prof. Georg Schett doctors discovered that inflammation is an important neurotransmitter – mediates between the brain and immune system and thereby influences the perception of pain significantly – the so-called tumor necrosis factor alpha. This effect was observed, the researchers also in humans. “Interestingly, drugs that inhibit tumor necrosis factor alpha, already successfully used worldwide for the treatment of rheumatoid arthritis,” said Schett. The drugs slowed the pain and increased well-being before the inflammation had subsided.

This effect can explain the researchers from Erlangen now if you inhibit the tumor necrosis factor, reduces the pain response in the brain, and the psychological changes such as tiredness and fatigue are positively influenced. “Our research results are probably due to a number of inflammatory diseases or infections transmitted also” hopes Schett.