Probability of finding an HLA-matched donor in immediate and extended families: the Jordanian experience

Information regarding the probability of finding HLA-matched related donor for a patient awaiting hematopoietic stem cell transplantation (HSCT) in developing countries is scanty. We performed a retrospective review of HLA genotypes and related data for 1254 consecutive patients and their families at King Hussein Cancer Center in Amman, Jordan, between 2003 and 2011 to evaluate the chance of finding HLA-matched donor. The median family size was 5 for all patients in the study (range, 1-14), and the average number of donors was 1.4 ± 0.9 for pediatric patients and 1.6 ± 0.9 for adults. Overall, the probability of finding an HLA-matched related donor at our center was 65.5% (60.6% in pediatric patients and 74% in adults). Of the total identified donors, 18% were nonsibling donors after an immediate and/or extended family search in the pediatric group, and 6% were nonsibling donors in the adult group. Overall, 13% of donors were nonsibling donors. We conclude that the probability of finding a matched related donor for HSCT in Jordan is much higher than that reported in Western countries and Asia (65% versus 25%). We expect a similar trend in other developing and Arab countries. We recommend integrating an extended family search before or concomitantly with an unrelated donor search.