Trying To Get A 2nd Kidney Transplant But Cpra Was

Trying to get a 2nd kidney transplant but Cpra was 81%. Hospital cut off was 80%. Can their be a margin of error in the test? I am very active on dialysis 3 x week, lift weights (light) and walk /run as much as possible. Fluid intake perfect also. I am 52 yr old male. The cutoff at 80% was for deceased donor list. But now my sister wants to give me one of her kidneys. Is the CPRA a different cutoff for a live donor? I had 1st kidney from live donor (brother in law) that lasted 15 years. I am fighting for my life here in texas . Thank you!