At the UMHS Histocompatibility Laboratory potential recipients are typed for HLA-A, B, C, DRB1,3,4,5, DQB1, DQA1, DPB1, DPA1 loci by medium/low resolution SSO molecular methods. Each recipient is screened to detect preformed anti-HLA antibodies. Patients may develop these antibodies in case of previous sensitization events like transfusion, pregnancies or previous transplant. When these antibodies are detected the Panel Reactive Antibody (PRA%) value is assigned and the anti-HLA antibody specificity is defined by Solid Phase Single Antigen assays. PRA% values are updated with a new sample every 3 months. For patients listed for transplant with a deceased donor the Histocompatibility Laboratory will updated PRA% and the Unacceptable Antigens list in the UNOS database every 3 months. Every month a fresh serum sample is mailed to the Organ Procurement Organization (OPO). This serum sample and the historic higher PRA% sample (peak) will be used for Flow Cytometric Crossmatch with matched deceased donors.

HLA Typing is genetic typing, and the data will not change. Typing cannot be performed repeatedly for patients or donors.