Scientists from the University of Liverpool, alongside Professor Alan Boyde from the Queen Mary University of London, have discovered a new cause of osteoarthritis, Medical News Today reports. The study focussed on a man who suffers from alkaptonuria (AKU) and found that the genetic condition caused changes to the physical properties of joint cartilage.
The metabolic disease causes homogentisic acid to build up in the joint cartilage, which is when issues with osteoarthritis began to arise. The team also studied eight other hips donated for research from other osteoarthritis sufferers and found similar results to the patient with AKU.
One surprising outcome from the study was the discovery of high density mineralised protrusions (HDMP) which had previously only been found in horses. Professor Jim Gallagher – who led the study and is from the University´s Institute of Ageing and Chronic Disease – noted that with the discovery of HDMP in humans the medical profession is now aware of “an important mechanism in the process which causes the disease.”
Typical treatment for osteoarthritis involves removing the calcium with acid to soften the bones and therefore make them easier to examine. For this study, however, the calcium was not removed meaning the HDMPs were not destroyed – allowing the scientists to recognise their presence for the first time.
Professor Gallagher concluded that studying rare diseases can often “help with new insights into much more common diseases” – the study into AKU has meant they are able to “add a new piece to the puzzle of an illness that affects millions.”
HDMPs are caused by the body attempting to fill cracks in joint cartilage, which then tend to snap; this then causes sharp particles to cause friction against healthy tissue.