New blood test to diagnose arthritis early

Patients could soon be diagnosed with early-stage arthritis several years before the onset of physical and irreversible symptoms, thanks to a new blood test developed by researchers.
Led by Dr Naila Rabbani of University of Warwick Medical School in the UK, the researchers developed a test that can provide an early diagnosis of osteoarthritis (OA) and also distinguish this from early-stage rheumatoid arthritis (RA) and other self-resolving inflammatory joint disease.
The test, which could be available to patients within two years, identifies the chemical signatures found in the plasma of blood joint proteins damaged by oxidation, nitration and glycation; the modification of proteins with oxygen, nitrogen and sugar molecules.

By diagnosing which type of arthritis a patient will develop at an early-stage will allow for appropriate treatment that will provide the best chance for effective treatment and potential prevention, the researchers said.
Patients with early-stage and advanced OA, RA or other inflammatory joint disease were recruited for the study alongside a control group of those with good skeletal health, with plasma and synovial fluid samples from both groups being analysed using mass spectrometry.
Through their analysis the researchers detected damaged proteins in characteristic patterns in the samples of those patients with early and advanced OA and RA, but were found at markedly lower levels in the samples of those in the control group - providing the researchers with the identifiable biomarkers necessary for early detection and diagnosis.

"Damage to proteins in the arthritic joint have been known for many years but this is the first time it has been exploited for early-stage diagnosis," Rabbani said.

"For the first time we measured small fragments from damaged proteins that leak from the joint into blood.
"The combination of changes in oxidised, nitrated and sugar-modified amino acids in blood enabled early stage detection and classification of arthritis - osteoarthritis, rheumatoid arthritis or other self-resolving inflammatory joint disease," said Rabbani.
"This is a big step forward for early-stage detection of arthritis that will help start treatment early and prevent painful and debilitating disease," Rabbani said.

The research was published in the journal Arthritis Research and Therapy.