Alloimmunization
Alloimmunization is an immune response to foreign antigens following exposure to genetically different cells or tissues. This phenomenon is particularly significant in the context of blood transfusion, organ transplantation, and pregnancy.
Pathophysiology[edit | edit source]
Alloimmunization occurs when the immune system of an individual recognizes and mounts an immune response against antigens from another individual of the same species. These antigens are typically proteins on the surface of cells, such as red blood cells (RBCs) or platelets.
Red Blood Cell Alloimmunization[edit | edit source]
In the context of blood transfusion, alloimmunization can occur when a recipient's immune system recognizes donor RBC antigens as foreign. This is most commonly seen with the Rh factor and other blood group antigens such as Kell, Duffy, and Kidd.
Platelet Alloimmunization[edit | edit source]
Platelet alloimmunization can occur in patients receiving multiple platelet transfusions. The human leukocyte antigen (HLA) system is often involved, and patients may develop antibodies against HLA antigens present on transfused platelets.
Pregnancy[edit | edit source]
During pregnancy, alloimmunization can occur if fetal blood cells enter the maternal circulation and the mother is exposed to fetal antigens that are not present in her own blood. This can lead to hemolytic disease of the newborn (HDN) if the mother develops antibodies that cross the placenta and destroy fetal RBCs.
Clinical Implications[edit | edit source]
Alloimmunization can lead to several clinical complications:
- Hemolytic Transfusion Reactions: Occur when transfused RBCs are destroyed by the recipient's immune system.
- Platelet Refractoriness: A condition where patients do not achieve the expected increase in platelet count following transfusion due to alloantibodies.
- Hemolytic Disease of the Newborn: A serious condition in which maternal antibodies attack fetal RBCs, leading to anemia and jaundice in the newborn.
Prevention and Management[edit | edit source]
Blood Transfusion[edit | edit source]
To prevent alloimmunization, blood banks perform crossmatching and provide antigen-matched blood, especially for patients who require chronic transfusions, such as those with sickle cell disease or thalassemia.
Pregnancy[edit | edit source]
In pregnancy, Rho(D) immune globulin (RhoGAM) is administered to Rh-negative mothers to prevent sensitization to Rh-positive fetal blood cells.
Research and Future Directions[edit | edit source]
Research is ongoing to better understand the mechanisms of alloimmunization and to develop strategies to prevent it. This includes the development of more precise antigen matching techniques and the use of immunomodulatory therapies.
See Also[edit | edit source]
References[edit | edit source]
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
|
WikiMD's Wellness Encyclopedia |
| Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD
