Arthritis Ireland Arthritis Ireland

Scientists have discovered that hydrogen sulphide (H2S) - the gas associated with the smell of rotten eggs - is present in the fluid inside the knee joint and may help to protect the joints against inflammation.

A research team at the Peninsula Medical School and the Royal Devon & Exeter NHS Trust compared the levels of H2S in blood and knee-joint synovial fluid samples from patients with rheumatoid arthritis, osteoarthritis and healthy volunteers.

They discovered that patients had much higher levels of H2S in their synovial fluid than healthy people. Synovial fluid levels were up to four times higher than the levels found in patients' blood and that the higher an individual's levels of H2S, the lower their number of inflammatory cells. According to the researchers, this suggests that H2S may help the body to control inflammation.

Dr Matt Whiteman, who led the study at the Peninsula Medical School in Exeter, said: "Traditional anti-inflammatory drugs are very potent and safe, but they can sometimes damage the stomach lining in some individuals leading to further complications.

"By identifying a clear link between levels of H2S in synovial fluid and inflammation ... we leave the way open for the development of H2S-based therapies that provide the benefits of traditional anti-inflammatory drugs without their unpleasant side-effects."

Dr Whiteman added that it may be possible to manipulate the body's H2S-producing enzymes to boost an individual's ability to deal with inflammation and tissue damage.

The findings are published in the Annals of the New York Academy of Sciences.