Excuse format and grammar. No native on the phone. TLDR at the end.

I would like to preface this by saying that I have a very good relationship with my sister. However our family has a history of kidney problems so we were discussing what would happen if we ever needed a kidney.

As she has type 0+ she can receive a donation from a 0+ or a 0-, that would include me as I am type 0-. However I can not receive from her. So I said I would not donate to her. The main reason is not because I want reciprocation but because I think I have it much harder and I dont want to risk being on a waiting list if my other kidney fails. Also she can do hemodyalisis.

She was visibly upset and maybe I did not worded my thoughts appropriately. Please I want to know if I did not consider other reasons.

An important note. 0+ accounts for 40% of the population but 0- is only 7%. That is why I will have it much harder if I am ever waiting for a transplant.

TLDR: I am 0- my sister is 0+, so she could never donate a kidney to me, I would not give her a kidney because if she ever needs one she can do hemodialysis, and she has a higher probability than me of finding a donant.