Graft Rejection

Your immune system works to destroy foreign substances that invade the body. But the immune system can’t distinguish between your transplanted liver and unwanted invaders, such as viruses and bacteria. So, your immune system may attempt to attack and destroy your new liver. This is called a rejection episode. About 64% of all liver-transplant patients have some degree of organ rejection, most within the first 90 days of transplant. Anti-rejection medications are given to ward off the immune attack.

Because anti-rejection drugs that suppress your immune system are needed to prevent the liver from being rejected, you are at higher risk for infections. This problem lessens as time passes. Not all patients have problems with infections, and most infections can be treated successfully as they happen.

After a liver transplantation, there are three types of graft rejection that may occur. They include hyperacute rejection, acute rejection and chronic rejection.

Hyperacute rejection is caused by preformed anti-donor antibodies. It is characterized by the binding of these antibodies to antigens on vascular endothelial cells. Complement activation is involved and the effect is usually profound. Hyperacute rejection happens within minutes to hours after the transplant procedure. Unlike hyperacute rejection, which is B cell mediated, acute rejection is mediated by T cells. It involves direct cytotoxicity and cytokine mediated pathways. Acute rejection is the most common and the primary target of immunosuppressive agents.

Acute rejection is usually seen within days or weeks of the transplant.

Chronic rejection is the presence of any sign and symptom of rejection after 1 year. The cause of chronic rejection is still unknown but an acute rejection is a strong predictor of chronic rejections. Liver rejection may happen anytime after the transplant. Lab findings of a liver rejection include abnormal AST, ALT, GGT and liver function values such as prothrombin time, ammonia level, bilirubin level, albumin concentration, and blood glucose. Physical findings include encephalopathy, jaundice, bruising and bleeding tendency. Other nonspecific presentation are malaise, anorexia, muscle ache, low fever, slight increase in white blood count and graft-site tenderness.