Association between HLA‐DRB1*01 and HLA‐DRB1*15 with alloimmunisation in transfusion‐dependent patients with thalassaemia

The influence of HLA allele and haplotype on RhE alloimmunization among pregnant females in the Chinese Han population

BACKGROUND AND OBJECTIVES

Anti-E alloantibody is the most common and important red blood cell (RBC) alloantibody during pregnancy. The study aimed to determine the correlation between RhE alloimmunization and human leukocyte antigen (HLA) allele polymorphism, as well as haplotype diversity, among pregnant individuals in the Chinese Han population.

STUDY DESIGN AND METHODS

All individuals included in our study were RhE-negative pregnant women of Chinese Han ethnicity, confirmed through serological testing. Pregnancy could be the only potential stimulating factor in RBC alloimmunization. Given the serological testing, the participants were divided into anti-E (responders) and non-anti-E-producing group (non-responders). The class I and II classical HLA genotyping were determined using next-generation sequencing, and the HLA genotype and haplotype frequencies were compared between the responders and non-responders.

RESULTS

In total, 76 responders and 94 non-responders were enrolled in this study. Comparison results showed that all HLA class I alleles had no difference between the two groups. For HLA class II phenotypes, responders had higher frequencies of HLA-DRB1*09:01, HLA-DQA1*03:02 and HLA-DQB1*03:03 phenotypes than non-responders, and the differences were statistically significant (pc < 0.05). In addition, the haplotype frequency of HLA-DRB1*09:01-DQA1*03:02-DQB1*03:03 in the RhE responders was significantly higher than in the non-responders (31.58% vs. 12.77%; odds ratio, 3.154; 95% confidence interval, 1.823-5.456; pc value, 1.25 × 10-3).

CONCLUSION

Our findings indicated that HLA-DRB1*09:01, HLA-DQA1*03:02 and HLA-DQB1*03:03 might be susceptible alleles for RhE alloimmunization among Chinese Han pregnant females. These three susceptible alleles constituted the unique three-locus haplotype in the RhE responders and collaborated to RhE alloimmunization.

Investigation of HLA susceptibility alleles and genotypes with hematological disease among Chinese Han population

Several genes involved in the pathogenesis have been identified, with the human leukocyte antigen (HLA) system playing an essential role. However, the relationship between HLA and a cluster of hematological diseases has received little attention in China. Blood samples (n = 123913) from 43568 patients and 80345 individuals without known pathology were genotyped for HLA class I and II using sequencing-based typing. We discovered that HLA-A*11:01, B*40:01, C*01:02, DQB1*03:01, and DRB1*09:01 were prevalent in China. Furthermore, three high-frequency alleles (DQB1*03:01, DQB1*06:02, and DRB1*15:01) were found to be hazardous in malignant hematologic diseases when compared to controls. In addition, for benign hematologic disorders, 7 high-frequency risk alleles (A*01:01, B*46:01, C*01:02, DQB1*03:03, DQB1*05:02, DRB1*09:01, and DRB1*14:54) and 8 high-frequency susceptible genotypes (A*11:01-A*11:01, B*46:01-B*58:01, B*46:01-B*46:01, C*01:02-C*03:04, DQB1*03:01-DQB1*05:02, DQB1*03:03-DQB1*06:01, DRB1*09:01-DRB1*15:01, and DRB1*14:54-DRB1*15:01) were observed. To summarize, our findings indicate the association between HLA alleles/genotypes and a variety of hematological disorders, which is critical for disease surveillance.

Prognostic Value Evaluation of HLA-DRB1*07:01, *10, *12, *13:01 Alleles for Alloimmunization in Transfusion-Dependent Thalassemia

BACKGROUND

Transfusion is a lifesaving treatment for lots of patients. However, in chronic blood recipients such as thalassemia patients, there are high concerns about alloantibody production that affects the quality of their life. Therefore, research on risk factors of alloimmunization has been started and followed. This study aimed at the determination of correlation probability between some HLADRB1 alleles and alloimmunization in Iranian thalassemia patients.

MATERIALS AND METHODS

The present study was conducted on 60 alloimmunized and 60 non-alloimmunized transfusion-dependent thalassemia patients. Antibody screening and identification tests were carried out using the tube method, and HLA-DRB1 genotyping was done using a single specific primer-polymerase chain reaction (PCRSSP).

RESULTS

The results of antibody screening showed that the most prevalent alloantibodies were Anti-K (46.7 %), and followed by Anti-E (32.5 %), Anti-C (15.8 %), Anti-D (13.3 %), Anti-e (8 %), and Anti-c (5.8 %), respectively. DRB1*07:01 was detected more in non-responder patients (28.3 %). However, data analysis showed that there is no significant relationship between DRB1*07:01, *10, *13:01 frequency among responder and non-responder groups (p = 0·195, 0.648, 0.402, respectively). There was not any significant correlation between HLA-DRB1*10 and *13:01 allele and alloimmunization. There was a significant association between HLA-DRB1*12 and alloimmunization (p < 0·05, OR = 2.071, CI: 1.716-2.501).

CONCLUSION

The findings of this study represented that there is a significant relationship between HLADRB1*12 and Kell and E alloantibodies. Although more developed studies on other HLA alleles are demanded, these findings can be valuable in determining important alloimmunization risk factors to better management of transfusion complications.

Back to base pairs: What is the genetic risk for red bloodcell alloimmunization?

Red blood cell (RBC) alloimmunization is a serious complication of blood transfusions, challenging selection of compatible units for future transfusions. Genetic characteristics may be associated with the risk of RBC alloimmunization and may therefore serve to identify high-risk patients. The aim of this systematic review was to summarize the available evidence on genetic risk factors for RBC alloimmunization. Electronic databases were searched up to April 2020 for studies (Search terms included transfusion, alloimmunization and genetic). A total of 2581 alloimmunized cases and 26,558 controls were derived from 24 studies. The alleles that were most frequently studied and that demonstrated significant associations in a meta-analysis with alloimmunization to the Duffy^a antigen were HLA-DRB1*04 (Odds Ratio 7.80 (95%CI 4.57-13.33)), HLA-DRB1*15 (OR 3.76 (95%CI 2.14-6.59)), and HLA-DRB1*03 (OR 0.12 (95%CI 0.05-0.29)). Furthermore, significant associations with anti-K formation was found for the alleles HLA-DRB1*10 (OR 2.64 (95%CI 1.41-4.95)), HLA*DRB1*11 (OR 2.11, (95%CI 1.34-3.32)), and HLA-DRB1*13 (OR 1.71 (95%CI 1.26-2.33)). Overall, the available evidence was of moderate to low quality, hampering interpretation of reported results. There is an urgent need for high quality evidence on genetic risk factors for RBC alloimmunization.