October 28, 2024, Immune Tolerance
Uremia is a significant disease impacting human health. Currently, kidney transplantation is the most effective treatment for uremia. Since Dr. Joseph Murray performed the first kidney transplant in the United States in 1954, nearly one million uremic patients worldwide have undergone kidney transplantation.
In recent years, with ongoing advancements in medical standards, the accumulation of clinical expertise among transplant physicians, improvements in surgical techniques, enhanced organ preservation methods, and the introduction of various new immunosuppressants, the clinical outcomes of kidney transplantation have significantly improved, and the incidence of acute rejection has notably decreased.
Nonetheless, rejection continues to be an independent risk factor for long-term kidney allograft survival. Therefore, we must place significant emphasis on the occurrence of rejection following kidney transplantation.
What Is Rejection?
Rejection occurs when a uremic patient receives a kidney with a different genetic background due to differing antigens between the donor and recipient. Without the use of immunosuppressants, the transplanted kidney may be “attacked” by the recipient’s lymphocyte-mediated immune-competent cells and antibodies. In brief, when a kidney transplant recipient receives a kidney, their immune system recognizes the “foreign” kidney as an “alien” entity, triggering an attack, destruction, and elimination response.
How Are Rejections Classified?
Clinically, rejection is typically categorized into four types based on the time of occurrence: hyperacute rejection, accelerated rejection, acute rejection, and chronic rejection. Based on its pathogenesis, rejection can be classified into cell-mediated (cellular) rejection and antibody-mediated (humoral) rejection. Allow me to briefly describe the different types of rejection.
Hyperacute rejection, as its name implies, occurs earliest, typically within minutes to hours after transplantation, generally within 24 hours, and is the most severe and aggressive form of rejection. Due to advancements in tissue matching technology and the use of immunosuppressants, such rejection has become extremely rare. However, there is currently no effective treatment for hyperacute rejection. Once the diagnosis is confirmed, the kidney should be removed promptly.
Accelerated rejection typically occurs within 1 to 7 days after transplantation. It is a type of rejection intermediate between hyperacute and acute rejection, often resulting in rapid loss of kidney allograft function. Accelerated rejection is generally challenging to treat, with poor outcomes; currently, clinicians commonly use anti-thymocyte globulin (ATG) and anti-lymphocyte globulin (ALG) for treatment.
Acute rejection is the most frequent type of rejection following kidney transplantation, occurring at any stage post-transplantation, though it most commonly appears within 1 to 3 months. The primary cause of acute rejection is often an insufficient dose of immunosuppressants due to various factors, such as sudden reduction or discontinuation of immunosuppressants, frequent vomiting and diarrhea, and significant short-term weight gain. If there is no specific cause for symptoms such as decreased urine output, weight gain, elevated blood pressure, and increased blood creatinine and urea nitrogen levels, acute rejection should be strongly suspected. At this point, prompt medical attention is necessary; failure to treat in a timely manner can lead to severe kidney transplant damage or even loss of function. When acute rejection occurs, clinicians often employ steroid pulse therapy or ATG therapy.
Chronic rejection typically occurs 3 to 6 months after transplantation and is the primary factor affecting the long-term survival of kidney allografts. The primary clinical manifestations include proteinuria, hypertension, and progressive kidney allograft dysfunction. Chronic rejection is mainly diagnosed through biopsy of the transplanted kidney. Currently, there is no particularly effective treatment for chronic rejection. The treatment goal is to prevent, to the greatest extent possible, the progressive deterioration of kidney function.
In summary, after kidney transplantation, patients should take immunosuppressants as prescribed by their doctor, schedule timely consultations, adjust medications under medical guidance, avoid arbitrarily reducing or discontinuing medications, and seek medical attention promptly upon noticing any abnormalities, valuing this hard-won kidney.
Written by | Xu Shihao, Edited by | Xu Shihao, Illustrations | Nancy
This article is an original publication of the “Kidney Transplantation, Zhongshan Hospital, Fudan University” WeChat public account. Reproduction requires authorization from this account and the original author, with proper attribution. To care for your kidneys, begin by following the “Kidney Transplantation, Zhongshan Hospital, Fudan University” WeChat public account. You can also click [Read the Original] to explore Kidney Transplant Recipients: How Much Do You Know About Self-Management?
