I donated a kidney to my Dad in 2000. It gave him an extra 23 years with us. He was on very low doses of his anti-rejection meds, partially due to us being a 4 out of 6 HLA type match, so the doctors were hopeful it would last him the rest of his life. It would have lasted far longer if ALS hadn't shown up.
Could you have gotten it back after he passed away? Or was the kidney forwarded on to someone else?