Abstract: Objective To establish a calculated panel reactive antibody (CPRA) method to analyze the donor-recipient
incompatibility rate in PRA-positive kidney recipients and estimate the probability of these recipients to receive kidney
transplantation. Methods Based on the database of HLA-A, -B, -DR genes and A-B, A-DR, B-DR, A-B-DR haplotype
frequencies collected from 2004 donors from Jan 2000 to Dec 2012, we analyzed CPRA in 202 PRA-positive recipients and
evaluated the consistency between PRA and CPRA assessments using a CPRA-Java calculator software, which returned a
percentage of CPRA (representing the probability of unacceptable HLA in the donor group) after input of HLA-specific
antibodies of a PRA-positive recipient. Result The mean PRA intensity of the 202 PRA-positive recipients was (23.12±17.83)%
with a mean CPRA% of (46.07 ± 23.30)% . A significant difference was found between the mean PRA% and CPRA% in low
sensitized recipients (PRA 0-10%) [(6.87 ± 2.41)% vs (21.63 ± 11.75)% , P<0.05) and in moderately sensitized recipients (PRA
10%-30%) [(20.15±5.70)% vs (50.56±16.86)%, P<0.05), but not in highly sensitized recipients (PRA> 30%); The concordance rates
between PRA% and CPRA% in the 3 groups were 19.35% (P<0.05), 10.99% (P<0.05), and 100% (P>0.05), respectively.
Conclusions Lowly sensitized kidney recipients might have a lower probability of actually receiving a transplant than PRA%
shows. A PRA%>30% is a risk factor for kidney transplantation. PRA reflects the sensitized level of a renal recipient, and
reliable detection of HLA antibody specificity is of critical importance. CPRA accurately reflects the probability of a recipient to
receive a transplant to assist clinicians in predicting the waiting time and selecting the transplant approach.