The HLA genes are associated with various autoimmune pathologies, with the control of the immune response also being significant in organs and cells transplantation. The aim of the study is to identify the HLA-A, HLA-B, and HLA-C alleles frequencies in the analyzed Romanian cohort. We performed HLA typing using next-generation sequencing (NGS) in a Romanian cohort to estimate class I HLA allele frequencies up to a six-digit resolution. A total of 420 voluntary donors from the National Registry of Voluntary Hematopoietic Stem Cell Donors (RNDVCSH) were included in the study for HLA genotyping. Peripheral blood samples were taken and brought to the Fundeni Clinical Institute during 2020–2021. HLA genotyping was performed using the Immucor Mia Fora NGS MFlex kit. A total of 109 different alleles were detected in 420 analyzed samples, out of which 31 were for HLA-A, 49 for HLA-B, and 29 for HLA-C. The most frequent HLA-A alleles were HLA-A*02:01:01 (26.11%), HLA-A*01:01:01 (12.5%), HLA-A*24:02:01 (11.67%), HLA-A*03:01:01 (9.72%), HLA-A*11:01:01, and HLA-A*32:01:01 (each with 8.6%). For the HLA-B locus, the most frequent allele was HLA-B*18:01:01 (11.25%), followed by HLA-B*51:01:01 (10.83%) and HLA-B*08:01:01 (7.78%). The most common HLA-C alleles were HLA-C*07:01:01 (17.36%), HLA-C*04:01:01 (13.47%), and HLA-C*12:03:01 (10.69%). Follow-up studies are ongoing for confirming the detected results.

Next-generation sequencing (NGS) has completely revolutionized the analysis of HLA genes, offering superior resolution and the possibility of identifying previously unknown or rare alleles. NGS technology allows for the complete sequencing of the the HLA locus, the analysis of coding and non-coding regions, and a detailed characterization of haplotypes, with essential benefits in areas such as organ transplantation and in studies of autoimmune diseases. The chapter explores the applications of NGS in personalized medicine, including the identification of neoantigens for oncology immunotherapies and the development of vaccines adapted to the genetic diversity of the population. Bioinformatic and ethical challenges are also discussed. By reducing the limitations of traditional methods and opening up new horizons for research and clinical applications, NGS is redefining the standards in HLA typing and is making a significant contribution to the progress of precision medicine.

Background and Objectives. Numerous genome-wide association studies have highlighted that chronic lymphocytic leukemia (CLL) is a lymphoproliferative disorder with an important genetic component. An important number of genes have been implicated in CLL etiology, with some of the most important being human leukocyte antigen (HLA) genes. The aim of this study was to analyze the association of CLL with certain HLA alleles in the Romanian population and to compare our results with previous findings. Materials and Methods. This study included 66 patients with CLL, diagnosed between 2020 and 2022, and 100 healthy controls. HLA class I and class II genes (HLA-A/B/C, HLA-DQA1/DQB1/DPA1/DPB1, and HLA-DRB1/3/4/5) were investigated using next-generation sequencing technology. Results. Several HLA alleles were strongly associated with CLL. The most important finding was that HLA-DRB104:02:01 ( , OR = 1.05) and HLA-DRB302:01:01 ( , OR = 1.03) have a predisposing role in CLL development. Moreover, we identified that HLA-A24:02:01 0.01 ( , OR = 0.38), HLA-DQA105:05:01 ( , OR = 0.56), HLA-DQB103:02:01 ( , OR = 0.40), and HLA-DRB401:03:01 ( , OR = 0.54 alleles have protective roles. Correlations between HLA expression and gender showed that women had a higher expression of protective HLA alleles when compared to men. Conclusions. Our data are the first to indicate that in Romanian patients with CLL, the HLA-A24:02:01 and HLA-DQA105:05:01 alleles have a protective role against CLL development, whereas HLA-DRB104:02:01 and HLA-DRB302:01:01alleles are positively associated with CLL.

Background and Objectives: The implications of the genetic component in the initiation and development of chronic lymphoproliferative disorders have been the subject of intense research efforts. Some of the most important genes involved in the occurrence and evolution of these pathologies are the HLA genes. The aim of this study is to analyze, for the first time, possible associations between chronic lymphoproliferative diseases and certain HLA alleles in the Romanian population. Materials and Methods: This study included 38 patients with chronic lymphoproliferative disorders, diagnosed between 2021 and 2022 at Fundeni Clinical Institute, Bucharest, Romania, and 50 healthy controls. HLA class I and class II genes (HLA-A/B/C, HLA-DQB1/DPB1/DRB1) were investigated by doing high resolution genotyping using sequence specific primers (SSP). Results: Several HLA alleles were strongly associated with chronic lymphoproliferative disorders. The most important finding was that the HLA-C*02:02 (p = 0.002, OR = 1.101), and HLA-C*12:02 (p = 0.002, OR = 1.101) have a predisposing role in the development of chronic lymphoproliferative disorders. Moreover, we identified that HLA-A*11:01 (p = 0.01, OR = 0.16), HLA-B*35:02 (p = 0.037, OR = 0.94), HLA-B*81:01 (p = 0.037, OR = 0.94), HLA-C*07:02 (p = 0.036, OR = 0.34), HLA-DRB1*11:01 (p = 0.021, OR = 0.19), and HLA-DRB1*13:02 (p = 0.037, OR = 0.94), alleles have protective roles. Conclusions: Our study indicates that HLA-C*02:02 and HLA-C*12:02 are positively associated with chronic lymphoproliferative disorders for our Romanian patients while HLA-DRB1*11:01, HLA-DRB1*13:02, and HLA-B*35:02 alleles have a protective role against these diseases.

HLA (Human Leukocyte Antigen) genes are a cornerstone of immunogenetics, having a significant impact on a wide range of biological processes and pathologies, from immune responses to the evolution of autoimmune and infectious diseases. Modern sequencing technologies, such as Next-Generation Sequencing (NGS), allow for detailed analysis of this complex system, providing unprecedented resolution. By integrating these advanced technologies, research in the HLA field opens new opportunities for personalized medicine, enabling early diagnosis, treatment of autoimmune diseases, transplantation, and immunotherapy. Furthermore, HLA sequencing plays a crucial role in vaccine development and innovative treatments, contributing to public health improvement and patient quality of life. In addition to its medical impact, HLA also plays an important role in anthropology, providing essential insights into human genetic diversity, population evolution, and adaptation to the environment, as well as interactions with pathogens. HLA studies help reconstruct human history by identifying migration routes and evolutionary mechanisms. To fully leverage the potential of HLA in research and clinical practice, bioinformatics and artificial intelligence methods are essential, enabling rapid analysis and interpretation of complex data. Technological advancements continue to transform the field, facilitating the development of new therapeutic strategies and high-precision diagnostics.