What happens when 0 blood receives B in a transfusion?

If a person with blood group 0 receives a blood transfusion from a person with blood group B, it can lead to a severe incompatible blood transfusion reaction. Here's what happens:

1. Incompatible Blood Type: Blood group 0 has no A or B antigens on its red blood cells, while blood group B has B antigens. When B blood is transfused into a person with 0 blood, the recipient's immune system recognizes the foreign B antigens as non-self.

2. Activation of Immune Response: The recipient's immune system immediately responds to the presence of the B antigens by producing antibodies specific to B blood. These antibodies are known as anti-B antibodies.

3. Agglutination of Red Blood Cells: The anti-B antibodies bind to the B antigens on the transfused red blood cells, causing them to clump together. This process is called agglutination.

4. Destruction of Red Blood Cells: Once the red blood cells are agglutinated, they can be destroyed by the recipient's immune system through a process called phagocytosis. Phagocytes, such as macrophages, engulf and break down the damaged red blood cells.

5. Hemolysis: The destruction of red blood cells leads to the release of hemoglobin, which is the oxygen-carrying protein inside red blood cells. Hemoglobin in the bloodstream can cause damage to blood vessels, kidneys, and other organs.

6. Symptoms and Complications: The incompatible blood transfusion reaction can cause a range of symptoms, including fever, chills, low blood pressure, shortness of breath, nausea, vomiting, and confusion. In severe cases, it can lead to a condition called hemolytic transfusion reaction, which can be life-threatening and may require immediate medical intervention.

Therefore, it is crucial to carefully match blood types before performing a blood transfusion to prevent such adverse reactions.