There are more than 100 different types of liver disease, but one in particular is starting to garner some serious attention in the medical world. Non-alcoholic steatohepatitis, or NASH, is unrelated to alcohol and comes about through the buildup of fat and scar tissue in the liver.
It is expected to overtake hepatitis C as the leading cause of US liver transplants by 2020, due in part to a lack of obvious symptoms and a simple test for diagnosis. Help may soon be on the way, however, with scientists discovering a way to detect telltale signs of NASH in its early stages, raising the prospect of a simple blood test and much earlier interventions.
Though scientists haven’t been able to pin down any one cause of NASH, obesity, type-2 diabetes and a lack of physical exercise are all common risk factors. Its onset is slow and can take place over years starting with the accumulation of fat cells in the liver, something known as non-alcoholic fatty liver disease (NAFLD). NASH is the more extreme form NAFLD and is typified by inflammation and scarring, which in turn leads to things like cirrhosis, liver failure or liver cancer.
As this scarring builds in the liver, the patient probably won’t show symptoms and the National Institute of Health estimates that the condition currently affects between two and five percent of Americans. There are factors that can raise suspicions, such as elevated levels of certain enzymes in routine blood tests, but a definitive diagnosis of NASH requires a liver biopsy which is expensive, invasive and usually comes too late to repair the damage.
Researchers at Cardiff University set out to find a non-invasive way to detect NASH that would be simpler and more likely to catch it during its formative stages. Using mass spectrometry, the team measured levels of lipids and metabolites in blood samples from 318 patients who had undergone liver biopsy following suspicions of NASH.
It discovered a set of proteins that "were significantly more common" in samples taken from patients with NASH, than those without. This raises the possibility of a simple blood test for NASH, but the researchers do note that the technique requires further investigation before it enters clinical use.
"Many people with non-alcoholic steatohepatitis do not have symptoms and are not aware they are developing a serious liver problem," says Dr You Zhou from Cardiff University’s Systems Immunity Research Institute." As such, diagnosis often comes after irreversible damage is done.
Our quicker and less invasive method of diagnosis could mean that more people with non-alcoholic fatty liver disease could be easily tested to determine whether they are progressing to non-alcoholic steatohepatitis, the more severe form of the disease."