HLA Class I and II allelic diversity among Ecuadorian transplant candidates: A comprehensive retrospective analysis

The Major Histocompatibility Complex (MHC) comprises over 220 genes encoding proteins that are vital for the functioning of the immune system. These genes are divided into three classes: HLA class I, II, and III. The polymorphism of MHC genes serves to enhance the immune response by increasing the diversity of antigen presentation. In Ecuador, a country with a diverse population comprising numerous ethnic groups, it is crucial to comprehend the distribution of HLA alleles in order to facilitate several health approaches such as personalized medicine and organ transplantation. The present study employed data from Ecuador's National Institute of Organ, Tissue, and Cell Donation and Transplantation (INDOT) from 2017 to 2022. The data were analyzed to determine the distribution of HLA class I (HLA-A, HLA-B, HLA-C) and class II (HLA-DRB1, DRB3, DRB4, DQB1) alleles. A total of 1530 HLA alleles were identified among the 2352 patients included in the study. The highest variability was observed in Class I alleles, with HLA-A02 (32 %) and HLA-B35 (21 %) being the most common. In the case of class II, the most prevalent alleles were DRB104 and DQB103, with frequencies of 25.1 % and 48 %, respectively. It is notable that significant regional variations in allele frequencies were observed across Ecuador. The findings of this comprehensive study provide valuable insights into Ecuador's HLA allele distribution, contributing to genetic research, personalized medicine, and organ transplant matching. However, the results also highlight the need for further studies to better understand genetic diversity and improve public health strategies.