Oxford BioDynamics PLC (AIM:OBD, OTC:OXBOF) has developed what it calls a "first-in-class" blood test to diagnose Chronic Fatigue Syndrome, a breakthrough that could help end years of uncertainty for patients struggling to obtain a clear diagnosis.

The AIM-listed diagnostics company said the test, created with researchers at the University of East Anglia, achieved 96% accuracy in identifying the condition, also known as Myalgic Encephalomyelitis, or ME. The findings have been published in the Journal of Translational Medicine.

Chronic Fatigue Syndrome is a long-term illness that causes severe exhaustion and other symptoms, affecting about 400,000 people in the UK. The absence of a definitive diagnostic test has meant many patients face delays or are misdiagnosed.

Professor Dmitry Pshezhetskiy, who led the study at the University of East Anglia, said: "We know that some patients report being ignored or even told that their illness is 'all in their head'.

"With no definitive tests, many patients have gone undiagnosed or misdiagnosed for years. This is a significant step forward. For the first time, we have a simple blood test that can reliably identify ME/CFS."

The test uses Oxford BioDynamics' EpiSwitch technology, which analyses "epigenetic" markers, meaning changes in how DNA is folded and regulated rather than the genetic code itself. The company said this approach had been key to achieving such a high level of accuracy.

Alexandre Akoulitchev, Oxford BioDynamics' chief scientific officer, said: "With this breakthrough, we are proud to enable a first-in-class test that can address an unmet need for a quick and reliable diagnostic for a complex, challenging-to-identify illness."

The company plans to seek a partner to co-develop or license the test for clinical use. It added that the same technology could also be applied to developing a test for long Covid, which shares similar biological features with ME/CFS.

Oxford BioDynamics' EpiSwitch platform is already used for other blood-based diagnostics, including its prostate cancer screening test, which it says has achieved 94% accuracy in the UK and US.