1-P: TOWARD A SAUDI CALCULATED PRA: SIMILARITIES AND DIFFERENCES WITH UNOS CALCULATOR.

Aim: The use of UNOS calculated panel reactive antibodies (cPRA) calculator to calculate sensitization for Saudi patients may not be relevant due to different donor pools. In this study, we compared HLA frequency of deceased donors at King Fahad Specialist Hospital-Dammam (KFSH-D) with UNOS frequency to evaluate the applicability of implementing the UNOS cPRA temporarily among Saudi patients. Methods: Medium resolution HLA class I and II genotypes were obtained from 148 deceased donors. Separate allele frequency was calculated for KFSH-D deceased donors belonging to West Asia, East Asia, South Asia and Africans. Phylip (v5) was used to calculate Nei’s genetic distance and generate Neighbor-joining (NJ) trees. Results: Majority of deceased donors at KFSH-D were of Asian descent.[figure1]In comparison to the antigen frequency in UNOS donors, some antigens were more frequent (eg, A24, B7, B8, B13, B27, B35, B44, DR10 and DQ5) while others were less frequent (eg, A3, DR1, DR4, DR7, DR13 and DR15). Genetically, South Asians and East Asians were closure to UNOS Asian donors while West Asians were closure to Caucasians.[figure2] Conclusions: Deceased donors analyzed at KFSHD have genetic similarity with Caucasian and Asian donors of UNOS. Adequate method for measuring the level of HLA sensitization based on national Saudi deceased donors HLA frequency is needed to establish a Saudi Arabian cPRA. [Copyright &y& Elsevier]