[Medical Q&A] Is it possible for a person's blood type to change?

Planner: Chinese Medical Association

Reviewer: Ning Yongzhong, Chief Technician, Beijing Chuiyangliu Hospital

Generally speaking, a person's blood type does not change throughout his life, but there are very special exceptions.

Blood type is determined by heredity and is mainly divided into A, B, AB and O. Each blood type is divided into Rh positive and Rh negative. Normally, a person's blood type will not change during his or her lifetime because blood type is determined by heredity and genes will not change easily once formed. However, in the following extremely special circumstances, blood type may change or temporarily change.

1. You may have received a non-identical blood type in an emergency. In this case, the blood type can be restored to the original type after 120 days of red blood cell metabolism.

2. If a person receives a bone marrow transplant, especially using stem cells from a donor, the new hematopoietic stem cells will produce red blood cells marked with the donor's blood type, while the recipient's plasma antibodies will weaken or disappear, red blood cell antigens will weaken, irregular antibodies will appear, autoimmune hemolytic anemia, cold agglutination, subtypes, etc. will occur, leading to changes in the recipient's blood type.

3. In rare cases, certain genetic variations may lead to changes in the expression of blood group antigens, but this is very rare.

4. Certain diseases, such as certain types of cancer or autoimmune diseases, may affect the expression of antigens on the surface of red blood cells, resulting in the detected blood type being inconsistent with the previous one, but this situation is also very rare.