[paul.fr]

why does our body sometimes reject blood and organs during transplant? Also are (why are) some organs, race specific?

[_Stefan_]

The body rejects or destroys cells that don't have special markers on their cell membrane that the immune system recognizes as its own.

Which organs are race specific?

[another_someone]

I am not aware (maybe someone can correct me) that no organ is specifically race specific, but different races have different distributions of markers (e.g. blood groups have different statistical distribution in different races, but that is different from saying any blood group only exists in one race, or never exists in another).

[iko]

Hi people,

shortly, there is a whole system of antigens that stimulate specific antibodies production, responsible for transplanted organ rejection.
It's called Major Histocompatibility Complex and its antigens are routinely detected on the cell suface of specialized white cells (lymphocytes) and called HLA, Human Leucocyte Antigen.
Today the respective genes are spotted from tiny samples of blood.
A fascinating field of Immunology and Genetics combined, difficult and complicated sometimes, surely it deserves a good read:

http://en.wikipedia.org/wiki/Human_leukocyte_antigen

I am not aware (maybe someone can correct me) that no organ is specifically race specific, but different races have different distributions of markers (e.g. blood groups have different statistical distribution in different races, but that is different from saying any blood group only exists in one race, or never exists in another).

Yes George,
    same thing like with blood groups.  There are some different combinations in different countries, they are hereditary, of course, genetically transferred like all the rest.

ikod

http://upload.wikimedia.org/wikipedia/en/4/4f/HLA_complex1.JPG

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