Medical Faculty News v25i1

Dr Seto found that rituximab reactivated HBV in 40 per cent of occult carriers within two years after they received the drug. Reactivation can lead to liver failure and even death if not properly controlled. These results showed that even if HBV is not active, these patients need preventative therapy — an approach that has now become standard around the world. Clinician-scientist Dr Walter Seto Wai-kay of the Department of Medicine draws inspiration from his patients to investigate and bring new insights in the areas of hepatitis B infection, ketamine drug use and liver cancer diagnoses. Each of his paths of discovery was inspired by problems that presented in patients and that had either not been described in the literature or did not have a successful medical strategy. His first breakthrough came more than ten years ago, when he treated a Mr Ng who passed away after the hepatitis B virus (HBV) he was carrying was reactivated after chemotherapy. About 560,000 people in Hong Kong are infected with HBV and, because infection typically does not show symptoms, around 25 per cent of cases end up developing cirrhosis and/or liver cancer unless they have regular check-ups or treatments. Dr Seto began exploring reactivation and focused on two triggers: the drug rituximab, which is used to treat a wide variety of diseases from haematological and rheumatological disorders to skin disorders and kidney diseases, and bone marrow transplantation. In the first case, he found that rituximab reactivated HBV in 40 per cent of occult carriers within two years after they received the drug. Reactivation can lead to liver failure and even death if not properly controlled. The study on bone marrow transplantation, funded by the Health and Medical Research Fund, similarly showed a high risk of reactivation. “These results showed that even if HBV is not active, these patients need preventative therapy,” he said — an approach that has now become standard around the world. His work on ketamine was inspired by a patient who used ketamine recreationally and had narrowed bile ducts on endoscopy. This is a highly unusual finding among Asian patients and Dr Seto’s report on the case was published in a high-ranking Gastroenterology journal. Afterwards, he did a full study, funded by the Beat Drugs Fund, involving collaborators at North District Hospital, radiologists at HKUMed, and three non-government organisations, whose social workers brought 257 users to him for magnetic resonance scans and follow-ups. He was able to determine that nearly 62 per cent (159) suffered bile duct damage but, just as importantly, those who quit ketamine saw a majority of their bile ducts return to normal. His third research area is on improving liver diagnosis using artificial intelligence (AI). Liver cancer patients often require repeated scans to confirm their diagnosis, which means treatment is delayed. Dr Seto had a patient in his 30s whose repeated scans showed shadows deemed non-cancerous, but Dr Seto spotted one suspicious nodule. An additional scan confirmed the patient had liver cancer. “Rather than depending on the human eye, I want to help physicians deal with these priority cases more effectively,” he said. Funded by the Innovation and Technology Fund, he and his colleagues from HKUMed and the HKU Faculty of Science have so far collected an image base of more than 3,000 CT scans that are being run through an AI machine learning process to improve diagnosis. The project is obtaining images from many Hong Kong hospitals and HKU-Shenzhen Hospital, of which Dr Seto is currently holding the position of Assistant Hospital Chief Executive (Research). Clinical Experience Drives Discovery 31 Medical Faculty News