CPRA estimates the percentage of donors who would be expected to have one or more unacceptable antigens, making the donor incompatible with the candidate. A candidate for transplantation may have unacceptable tissue typing (HLA) antibodies for any given donor; this estimates the number of donors who would be incompatible with the candidate. Recipient's sera are reacted with a panel of donor lymphocytes from 100 people to ascertain pre-existing HLA antibodies against prospective donors. The percent to which the potential recipient reacts yields the percent reactive panel. The percentage reflects the degree to which a potential recipient has pre-formed tissue typing antibodies for any given donor; the higher the percentage, the more sensitized the recipient and more difficult to find a donor who is compatible.
Health Resources and Services Administration (n.d.). Organ Procurement and Transplantation Network, Allocation calculators. Richmond, VA: Author. Retrieved from: http://optn.transplant.hrsa.gov/converge/resources/allocationcalculators.asp?index=78