Trends and challenges in searching for HLA-matched unrelated donors in Israel

Despite the large local donor registries, for some Israeli patients an HLA-matched unrelated donor cannot be identified within a favorable time period. This study aims to retrospectively analyze donor search processes in our transplantation center in order to provide a basis to enhance the efficacy of these procedures. We analyzed 121 donor searches performed in the last 5 years in our center and investigated various parameters characterizing these searches. For over 80% of patients, a donor matched at least at 9/10 alleles was identified, mostly from the local donor registries. The probability of finding a 10/10 HLA-matched donor in a local registry for patients of the Arab minority was significantly lower than patients of Jewish origin (25% versus 64%, respectively; p<0.05). Furthermore, we found that identifying a fully matched donor for an adult patient is significantly more probable than for a pediatric patient (66% versus 43%, respectively; p<0.05). These data indicate of dissimilarities between HLA profiles of the older versus the younger patients, which influence their probability to find a suitable donor. In conclusion, in spite of the large size of local donor registries, they do not optimally reflect the immunogenetic profiles of patients of ethnic minorities and of pediatric patients.