Can a person with O + blood group donate kidney to a person with B + blood group?

Q: Can a person with O+ blood group donate kidney to a person with B+ blood group (if they are siblings)?

A:Donor with Blood type O can be a potential donor to a recipient with blood type B even if they are siblings. However, in addition to ABO blood type compatibility between the donor and the recipient, there are additional major antigens in the body cells, which need to be matched in order to achieve a long and successful functioning of transplanted kidney. These tests are done by process called "tissue typing". The greater the matching of antigens, the lower are the chances of rejection of the transplanted organ. Chances of matching antigens are high among the relatives, especially among the siblings as in your case.