Researchers at the University Warwick, UK, have come up with a simple blood test for osteoarthritis that can detect the condition several years before the onset of physical symptoms.
A biomarker, citrullinated proteins (CPs) suspected to be present in blood of people with early stage rheumatoid arthritis (RA) was identified. Patients with RA have antibodies to CPs, but it was not thought that this was the same for those with osteoarthritis (OA).
"This is a remarkable and unexpected finding. It could help bring early-stage and appropriate treatment for arthritis which gives the best chance of effective treatment," said lead researcher, Dr Naila Rabbani. "It has been long established that the autoimmunity of early-stage RA leads to antibodies to CPs, but the autoimmunity, and hence antibodies, are absent in early-stage OA", she added.
The researchers produced an algorithm of three biomarkers, CPs, anti-CP antibodies and hydroxy-proline, the bone derived substance. The major types of arthritis can be detected and discriminated at the early stages using the algorithm and with a single test they could prevent joint damages.
"Using this knowledge and applying the algorithm of biomarkers we developed provides the basis to discriminate between these two major types of arthritis at an early stage," Rabbani said.
The test would help in early diagnosis and the ability to discriminate between RA and OA could provide a number of benefits to patients.
"Detection of early stage-OA made the study very promising and we would have been satisfied with this only but beyond this we also found we could detect and discriminate early-stage RA and other inflammatory joint diseases at the same," Rabbani said. "This discovery raises the potential of a blood test that can help diagnose both RA and OA several years before the onset of physical symptoms."