Drugs to reduce the risk of rejection are given to organ transplant patients because patients because the donated organ contains?

When a person receives a transplant, the immune system recognizes the transplanted organ as foreign. This is because the immune system discovers that the antigens in the cells of said transplanted organ are different. This non-compatibility triggers a transplant rejection.

Explanation:

The immune system protects the body from harmful substances such as microorganisms, toxins, etc. These substances have proteins known as antigens, which cover their surface. When these antigens are inside the body, the immune system recognizes that they do not belong to the body and attacks them. This happens in the case of transplants. To prevent this, doctors check both the donor and the person who will receive it. This typification ensures that the organ is as equal as possible to the tissues of the organ's recipient.

The answer is; cell surface receptors that are recognized as antigens by the recipient's immune system.

Therefore the organ is attacked as a foreign substance. This is why organ transplants are given by the closest family member to reduce the antigen variability that causes transplant rejection. Tissue typing is done to ensure that the organ or tissue is as similar as possible to the tissues of the recipient.