Advanced liver disease is a death sentence unless you can get on the organ transplant list and secure a liver from a donor. People with chronic hepatitis infections, alcoholic or nonalcoholic cirrhosis, diseases such as systemic lupus erythematosis, liver cancer, or other such diseases have subfunctional livers that can threaten the life of the patient.
The liver performs a whole long list of specific functions for the body. It synthesizes many important blood proteins and that includes many of the clotting factors that clot our blood. It detoxifies foreign molecules from the environment that eat or breathe in so that the kidney can excrete them. The liver also turn nitrogenous wastes into urea, which is less toxic and easily excreted. It also recycles lactic acid from exercising muscles by converting it into sugar. It also synthesizes cholesterol and regulates the flow of cholesterol throughout the body. This a short list of all the functions of the liver. Without this organ, we are toast. However with just 6,000 available organs for some 100,000 patients each year, chances of winning the liver lottery are slim. And if you’re elderly or suffering from another disease, the chances are closer to zero.
The liver has tremendous ability to regenerate. If a living donor wishes to donate part of their liver to a liver transplant candidate, a portion of the donor’s liver is given to the patient, and the donor will regrow the rest of their liver. In a damaged liver, the organ is too full of scar tissue to regenerate, since scar tissue inhibits proper regeneration. Therefore, what if we just move the sight of regeneration to a new place?
At the University of Pittsburgh, Eric Lagasse and his colleagues at the McGowan Institute for Regenerative Medicine have been examining this very strategy. Lagasse found that lymph nodes, those small way stations along the lymphatic vessels that contain immune cells that survey the passing material to determine if it is a foreign invader or just a casual visitor that means your body no harm, can act as tiny bioreactors for growing liver cells. By turning lymph nodes into incubators that can grow liver cells, enough liver cells can grow to generate an entirely new liver. Creating a whole set of miniature new livers might take as little as obtaining liver cells from healthy donors and placing them inside the lymph nodes of patients suffering from liver disease.
Adaptation of this technology to the clinic could conceivably create enough new liver cells to repopulate or even replace a patient’s damaged liver. The problem at this point is one of scale. If this technology could be scaled up, we could be growing new livers in the patient’s own body. So far it works in mice. Could it work in humans?