How and why does the body reject a transplanted kidney? What happens then?


Rejection is when the organ recipient’s immune system recognizes the donor organ as foreign and attempts to eliminate it. It often occurs when your immune system detects things like bacteria or a virus. 

At least one episode of acute rejection is common within the first year after a transplant, but it can also occur years after a transplant. Despite the use of immunosuppression therapy, acute rejection can occur and often lead to chronic rejection. 

Chronic rejection, which is characterized by gradual loss of organ function, is an ongoing concern for transplant recipients because it can occur weeks, months or years after transplantation. Organ recipients should be aware of the signs of both acute and chronic rejection. Call your doctor as soon as you experience any of them. Symptoms include:

  • Pain or tenderness over the transplant site
  • Fever
  • Flu-like symptoms such as chills, nausea, vomiting, diarrhea, tiredness, headache, dizziness and body aches and pains
  • Change in pulse rate
  • Weight gain
  • Swelling
  • Less urine

You can help prevent rejection by taking the medication as prescribed by your specialist, and by following your diet and routine closely. Any signs or symptoms that appear unusual – including fever or soreness in the area of the kidney – should be reported to your health care professional.