Graft-versus-host disease

Definition

Graft-versus-host disease (GVHD) is a serious condition that occurs when donor immune cells attack the recipient's tissues following a transplant. This reaction typically arises after allogeneic transplants, where the donor and recipient are genetically different, leading to complications in the recipient's immune system due to mismatched histocompatibility antigens. GVHD highlights the significance of histocompatibility in organ transplants and is one of the primary forms of transplant rejection that can impact patient outcomes.

5 Must Know Facts For Your Next Test

1. GVHD can be acute or chronic, with acute symptoms usually appearing within 100 days post-transplant and chronic symptoms potentially developing later.
2. The skin, liver, and gastrointestinal tract are common targets for damage in GVHD, leading to symptoms like rashes, jaundice, and diarrhea.
3. Preventative measures for GVHD include careful matching of donor and recipient MHC antigens and administering immunosuppressive drugs post-transplant.
4. GVHD is more common in cases where the transplant comes from a sibling or an unrelated donor rather than from an identical twin or autologous sources.
5. Despite being a complication, some aspects of GVHD may have beneficial effects in combating residual cancer cells following hematopoietic stem cell transplants.

Review Questions

• How does graft-versus-host disease relate to histocompatibility and what role does it play in transplant success?
  • Graft-versus-host disease is directly related to histocompatibility because it arises when there is a mismatch between donor and recipient MHC proteins. When donor immune cells recognize the recipient's tissues as foreign due to these differences, they mount an attack, leading to GVHD. Proper histocompatibility matching is crucial for reducing the risk of GVHD and ensuring transplant success, as it helps create a more harmonious environment for the transplanted cells.
• Discuss the various factors that can influence the occurrence and severity of graft-versus-host disease in allogeneic transplants.
  • Several factors can influence the occurrence and severity of graft-versus-host disease in allogeneic transplants. These include the degree of histocompatibility between donor and recipient, the source of the graft (such as peripheral blood versus bone marrow), the age and overall health of both the donor and recipient, and the conditioning regimen prior to transplantation. Additionally, immunological factors such as the presence of specific T-cell subsets in the graft can also impact how aggressively the donor's immune system will react against the recipient's tissues.
• Evaluate the implications of graft-versus-host disease on treatment strategies for patients undergoing allogeneic transplantation.
  • The implications of graft-versus-host disease on treatment strategies are significant, as healthcare providers must carefully balance preventing GVHD while ensuring effective anti-cancer responses from the graft. This often involves employing immunosuppressive therapy to minimize GVHD risk but can increase susceptibility to infections or reduce anti-tumor effects. Additionally, clinicians may use tailored approaches like selective T-cell depletion or enhanced histocompatibility matching techniques to manage GVHD risk while maximizing therapeutic benefits for patients undergoing allogeneic transplantation.

Related terms

Histocompatibility: The compatibility of tissue between donor and recipient, determined by the presence of specific molecules on cell surfaces known as major histocompatibility complex (MHC) proteins.

Allogeneic Transplantation: A type of transplant where the donor and recipient are different individuals, often leading to an increased risk of GVHD due to immune response differences.

Immunosuppressive Therapy: Medications or treatments used to suppress or reduce the strength of the body's immune system to prevent transplant rejection, including GVHD.