Liver disease can start impacting the brain within two weeks, even if no physical symptoms are evident.
That’s according to researchers from the Universities of Geneva and Lausanne, the Vaud University Hospital Centre, the Centre for Biomedical Imaging, the Federal Polytechnic School of Lausanne and the University Hospitals of Geneva. They all teamed up to do a deep dive of hepatic encephalopathy which occurs when the diseased liver can no longer filter a number of substances, leading to psychological, motor and neurocognitive disorders.
Brain impact shows up before liver disease symptoms do
The researchers observed rats with chronic liver disease for a period of eight weeks. During that time frame, the scientists discovered molecular changes affecting the brain as early as two weeks after the liver began dysfunctioning. The rats had little symptoms of liver disease at that point. The signs of the disease including jaundice, malnutrition or water in the stomach began to appear between weeks four and eight. Also evident was an excess of ammonium, known to be present in the brain with hepatic encephalopathy as well as vitamin C and creatine. The latter two molecules were never observed before in the brain as liver disease sets in.
“Ammonium is produced when proteins break down,” says Valérie McLin, a professor in the Department of Pediatrics, Gynecology, and Obstetrics at UNIGE’s Faculty of Medicine and HUG in the report which was published in the Journal of Hepatology. “Some of the ammonium goes to the brain, where it is transformed into glutamine and used to produce neurotransmitters. The rest is filtered by the liver and excreted in the urine. When the liver malfunctions, too much ammonium goes to the brain. The resulting rise in glutamine production can trigger cerebral edema and, in some cases, hepatic encephalopathy.”
Brain damage from liver disease could be detected early
The research, published in the Journal of Hepatology, could help detect brain damage caused by liver disease prior to the patient's health suffering, the researchers said in a press release announcing the work. “The results suggest that an MRS brain scan might detect the neurological manifestations of chronic liver disease long before the appearance of the first symptoms,” the researchers concluded.
Understanding how the liver works have long been a focus of many researchers and for good reason. According to the Public Health England, liver disease is the fifth cause of death in the UK and the third most common cause of premature death. Aiming to combat those statistics, researchers at King's College in London recently identified a new type of cell that could regenerate liver tissue. The newly discovered cell is called a hepatobiliary hybrid progenitor (HHyP) and can grow into the two main cell types of the adult liver.