Seoul St. Mary's Hospital researchers identify gut-liver IgA immune axis

A research team led by Professor Sung Pil-soo at Seoul St. Mary's Hospital has identified the ‘gut-liver IgA immune axis,’ a mechanism where increased Immunoglobulin A (IgA) contributes to liver inflammation and damage in alcohol-associated liver disease.

While IgA is a protective antibody that prevents bacteria and viruses from penetrating mucosal surfaces like the gut, the study found that in cases of excessive alcohol consumption, elevated IgA levels in the blood lead to accumulation in liver tissue. Once in the liver, IgA interacts with immune cells, specifically monocytes and macrophages, triggering an inflammatory response involving interleukin-1 beta (IL-1β).

Using animal models, the researchers demonstrated that administering FTY720, a drug that regulates immune cell migration, reduced both IgA binding to liver macrophages and subsequent liver damage. The study, published in the journal ‘Gut’, suggests that IgA is not merely a byproduct of liver disease but a direct driver of inflammation. The team aims to further investigate selective ways to regulate this immune axis as a potential therapeutic strategy and biomarker for liver disease.