When an organ is replaced with someone else’s, the body needs immunosuppressants because of the foreign object now in the body. Why is the same not true for a blood transfusion?

Question

Basically title! I was wondering about this. Thanks!

In: 144

Answer 1

We do have an immune response to tranfused blood. Cells of the immune system will ‘look’ at particular proteins on the surface of red blood cells and try to destroy those cells if those proteins are too different to those made by the host body.

But usually – as long as the correct blood type is used (it’s a way of classifying blood according to the type of proteins on cell surfaces) then it’s usually ok, and there’s no immune response, or it’s a very muted one that isn’t too catastrophic. It’s not uncommon for people to become a little feverish as the blood transfusion goes in: that’s the immune system having a bit of a grumble… it’s recognising that the incoming blood isn’t quite right, but it’s not sufficiently wrong to switch the immune response all the way on.

If someone is given blood of the wrong type, this can lead to a potentially very serious and potentially fatal immune response as the body goes all out to destroy the incoming blood cells, and this sets in chain a series of events that can be very harmful.

Sometimes people who have had lots of transfusions of blood or platelets can become quite sensitive to blood products, and transfusions make them feel quite ill. They may need ‘irradiated’ blood products, which have been treated with radiation to destroy any identifying proteins.