Representative image. Photo: Pixabay
Hong Kong: A few years ago, Joy Milne made news for doing something even the bleeding edge of science could not: the ability to detect Parkinson’s without knowing the patient’s symptoms or medical history. The Scottish woman’s heightened sense of smell allowed her to detect an odour that patients of Parkinson’s had and others did not.
Scientists proposed that Milne could detect a chemical change in skin oil, or sebum, in patients of the degenerative disorder which affects the central nervous system. As a test, they asked her to smell T-shirts worn by people who had Parkinson’s and those who did not. Milne correctly identified all the T-shirts worn by Parkinson’s patients. But she also said that one patient who did not have the disease also had the scent. Eight months later, that individual was diagnosed with Parkinson’s.
In 2019, researchers at the University of Manchester identified molecules linked to the disease found in skin swabs and have developed a test. If this test can be used in a hospital setting, it could prove to be a game changer.
Two research centres in Hong Kong’s Science Park are attempting to make similar progress in developing early detection tests. The Wire Science had the opportunity to visit the centres as part of the Hong Kong Laureate Forum.
Many people carry Epstein-Barr virus (EBV) and it does them no harm. But in Southern China, EBV is linked to the high incidence of nasopharyngeal cancer. Though a full understanding of the interaction between EBV infection, genetic factors, and environment in the development of nasopharyngeal cancer has not yet been achieved, EBV screening has been a useful method to detect the cancer.
The researchers at the Centre for Novostics, in association with the Chinese University of Hong Kong, have taken this one step ahead – to find ways for early detection and future risk. They screened over 20,000 middle-aged males in Hong Kong who did not have symptoms of nasopharyngeal cancer. They were testing blood plasma for short DNA fragments of EBV that are released by nasopharyngeal carcinoma cells. Subjects with initial positive test results were retested four weeks later, out of which 309 subjects had persistently positive results. Further investigation with nasal endoscopic examination and magnetic resonance imaging (MRI) showed that 34 subjects had nasopharyngeal cancer.
But the study also posed a problem: there were a large number of false positives. Though some subjects persistently tested positive for plasm EBV DNA, cancer was not identified on endoscopy or MRI.
The scientists decided to rescreen around 17,000 participants with no cancer identified in the first round, three to five years later. Among them, 423 persistently tested positive for plasma EBV DNA on initial and follow-up tests. From these, 24 were confirmed as having NPC. In more than two-thirds of these patients, cancer was detected in stages 1 or 2, significantly earlier than through other methods – when 80% of cases are detected in stage 3.
Meanwhile, researchers at the Centre for Eye and Vision Research have developed a diagnostic tool for early detection of macular degeneration, an age-related medical condition which may result in blurred or no vision in the centre of the visual field. It affects more than 200 million patients worldwide, mostly aged over 50. It progresses in three stages: early, intermediate, and late. Because there are no symptoms, in the early stage it is hard to diagnose. And as the disease progresses, it becomes harder to manage.
The scientists at the Centre for Eye and Vision Research have used a quantum imaging diagnostic tool to solve the problem. A prototype device, called ‘Structured Light Observation and Perception Evaluation’, generates unique images which healthy eyes can see clearly but eyes with AMD do not.
The scientists plan to create a miniature setup of the device for potential clinical use, following which they will conduct clinical trials to test its diagnostic capabilities. If the trial proves successful, Dr Mukhit Kulmaganbetov, who is leading the project, said that they will build a commercially viable prototype. While there is no way to reverse macular degeneration yet, vision loss can be delayed – and early detection helps keep degeneration at bay for longer.