Typing Of Human Leukocyte Antigen Class Research Articles

Molecular Typing of Human Leukocyte Antigen-Class I (HLA-A, HLA-B) & Human Leukocyte Antigen-Class II (HLA-DR) in Carcinoma Cervix and Its Association with Staging

Molecular Typing of Human Leukocyte Antigen-Class I (HLA-A, HLA-B) & Human Leukocyte Antigen-Class II (HLA-DR) in Carcinoma Cervix and Its Association with Staging

Evolution and Immunogenetics of Natural Killer Cell Receptors in Health and Disease

Natural killer (NK) cells are phenotypically diverse lymphocytes that contribute to innate immunity, adaptive immunity and placental reproduction. Unlike B and T cells, NK cells do not use rearranging genes to make diverse antigen receptors that are clonally expressed. Instead, NK cells express diverse combinations of a variety of receptors that are encoded by conventional non-rearranging genes. Several of these receptors are specific for conserved and variable determinants of major histocompatibility complex (MHC) class I molecules. In humans, the killer-cell immunoglobulin-like receptors (KIR) are a diverse and polymorphic family of NK-cell receptors that recognize determinants of human leukocyte antigen (HLA)-A, B and C, the polymorphic human MHC class I molecules. HLA-A, B and C are the most polymorphic of human genes, and they correlate with susceptibility to a wide range of diseases and clinical outcomes, including allogeneic hematopoietic cell transplantation (HCT). During NK-cell development, interactions between epitopes of HLA class I and KIR educate the NK cells to recognize the normal expression of these epitopes on healthy cells, and to respond to unhealthy cells in which that expression is perturbed. In the context of HCT, certain types of HLA class I mismatch enable donor-derived NK cells to make an alloreactive and beneficial graft-versus-leukemia response. Although it is likely that all placental mammals have NK cells, only a small minority of these species has a diverse KIR family like that in humans. These comprise the simian primates: New World monkeys, Old World monkeys and the great apes. Under pressure from diverse and rapidly evolving pathogens, both the MHC class I and KIR gene families have been driven to evolve rapidly. Consequently, much of their character is species-specific. This is especially true for the human KIR gene family, which is qualitatively different from that of our closest relatives, the chimpanzees. Whereas chimpanzee KIR haplotype diversity represents variations on a theme of genes encoding robust MHC class I receptors, humans have an even balance between group A KIR haplotypes encoding robust HLA class I receptors and group B KIR haplotypes encoding receptors that, to varying degree, have been subject to natural selection for reduced functional recognition of HLA class I. A balance of A and B is present in all human populations and thus appears essential for the long-term survival and competitiveness of human communities. Whereas the A KIR haplotypes correlate with successful defense against viral infection, maternal B KIR haplotypes correlate with reproductive success and donor B KIR haplotypes improve the outcome of allogeneic HCT as therapy for acute myeloid leukemia. DisclosuresNo relevant conflicts of interest to declare.

Human Leukocyte Antigen Proficiency Testing for Central and Eastern Europe: A Summary of Over 10 Years of Activity

The first trial of human leukocyte antigen (HLA) Proficiency Testing for Central and Eastern Europe (formerly Proficiency Testing of HLA class I Typing for Central and Eastern Europe) was organized in 1999 with 5 Polish institutions that were involved in HLA typing. Since then, 46 HLA laboratories in 13 countries have participated in our external proficiency testing schemes. The workshop conducted by our institution meets the expectations of the European Federation for Immunogenetics to provide data on the reliability of histocompatibility testing. Our standardization workshop currently covers serological typing of HLA class I A and B loci and DNA typing at the low- and high-resolution level of HLA class I (A, B, C) and class II (DRB1, DQB1) loci. It has >30 HLA laboratories participating each year. Thirty-two laboratories in 9 countries participated in the last session, the 15th workshop in 2009. Twenty-three laboratories submitted results of HLA class I typing by serology; 28 participated in HLA class I DNA typing and 28 participated in HLA class II DNA typing, including 5 and 7 laboratories that sent results of high-resolution typing for class I and class II specificities, respectively. Continuous improvement is seen with respect to both serology and DNA typing, although some doubtful results are still reported.

High-throughput sequence-based typing strategy for HLA-DRB1 based on real-time polymerase chain reaction

DNA sequencing is the gold standard for high-resolution genotyping of the highly polymorphic human leukocyte antigen (HLA) loci. In the case of hematopoietic stem cell transplantation, four-digit typing of HLA class I and II genes is indicated. We developed a group-specific, real-time polymerase chain reaction (PCR) strategy for amplification of DRB1 applying TaqMan chemistry on different real-time machines. For evaluation of genotyping accuracy and ambiguity resolution, 115 well-characterized samples were adapted. Separate analysis of each allele was possible in 100 samples (87%). Of the samples, 13% (n = 15) showed amplification in one of the eight group-specific PCR mixes: one sample according to the group DRB1*15, 16, along with 14 samples according to the group DRB1*03, *11, *13, *14. Further testing of the 14 (12.2%) samples associated with group DRB1*03, *11, *13, *14 was performed with specific intron primers. In conclusion this typing scheme generates results within 1 day, thereby making sequencing for different requirements attractive.

Human Leukocyte Antigen-A,-B,-C and -DR Alleles and Soluble Human Leukocyte Antigen Class I Serum Level in Ménière's Disease

Previous studies have suggested that many human leukocyte antigen (HLA)-A,-B,-C and -DR alleles are associated with Ménière's disease (MD), an inner ear disorder with a proposed autoimmune etiopathogenesis. Despite some discrepancies many reports are in agreement with a hypothesis suggesting an influence of serologically detected HLA-C products in the susceptibility to the disease. To confirm these data we investigated the distribution of HLA-A,-B,-C and-DR antigens that well define the HLA polymorphism using DNA typing. Furthermore, as autoimmune factors have been claimed to play a role in MD, we investigated the serum level of soluble HLA class I (sHLA-I). Molecular typing of HLA class I and II was performed using polymerase chain reaction sequence-specific primers in 41 patients affected by MD, 34 patients affected by other inner ear diseases (OIDs) and 101 healthy subjects. An ELISA technique was employed to investigate the serum level of sHLA-I in 17 MD patients, 10 OID patients and 83 healthy subjects. The results showed a significantly increased frequency of the Cw*07 specificities in MD patients when compared to OID patients (63.4% vs 32.3%; p =6.9 2 10 -3 ; relative risk [RR]=3.6) and healthy subjects (63.4% vs 35.6%; p =2.28 2 10 -3 ; RR =3.1). The sHLA-I concentrations detected in sera did not differ significantly between MD patients (616 - 271 ng/ml), OID patients (570 - 307 ng/ml) and healthy subjects (518 - 340 ng/ml).