Human neutrophil alloantigen genotype frequencies in Thai blood donors

Phenotyping and Genotyping of HNA: Prevalence, Risk of Alloimmunization, and HNA Incompatibilities in Indians

Background

Antibodies to human neutrophil alloantigens (HNA) are involved in the pathophysiology of several clinical conditions including transfusion-related acute lung injury (TRALI), alloimmune and autoimmune neutropenia, and febrile nonhemolytic transfusion reactions leading to neutropenia. The cognate antigens are polymorphic structures expressed on several glycoproteins on the neutrophils, i.e., antigens HNA-1a, -1b, -1c, and -1d on Fc-γ-receptor IIIb; HNA-2 on CD177; HNA-3a and -3b on choline transporter-like protein 2; HNA-4a and -4b on CD11b/αM subunit of the αMβ2-integrin (CD11b/CD18, Mac-1, CR3); and HNA-5a and -5b on αL-subunit (CD11a) of the αLβ2 integrin (CD11a/CD18), leukocyte function associated molecule (LFA)-1. Currently, there is a lacuna of diagnostic methods for detection of HNA in India. This study aimed to determine the HNA frequencies in Indians, estimate the risk of alloimmunization, and prepare typed neutrophil panels, which can be used to detect HNA antibodies in neutropenia cases.

Material and Methods

EDTA blood samples were collected from random 1,054 blood donors. HNA-2 was phenotyped on fresh EDTA samples using FITC labelled monoclonal anti-CD177 by flowcytometry. HNA-1 (FCGR3B) genotyping was carried out by DNA sequencing and PCR-RFLP. Antigens of HNA-3 (SLC44A2) and HNA-5 (ITGAL) were genotyped by PCR-RFLP using TaqαI and Bsp1286I restriction enzymes, respectively, while HNA-4 (ITGAM) was genotyped by PCR-SSP.

Results

Allele frequencies of FCGR3B*01, FCGR3B*02, and FCGR3B*03 were found to be 0.433, 0.444, and 0.087, respectively. FCGR3B*01+*02+*03- was the most common genotype (33.78%). Ten individuals showed deficiency of FCGR3B individuals, while 23 showed hyperexpression, i.e., FCGR3B*01+*02+*03+. FCGR3B*04and *05 occurred with a frequency of 0.002 and 0.024. HNA-2 was found to be a high frequency antigen occurring in 98.8% population. Four percent individuals showed atypical expression of CD177 on their neutrophils. Allele frequencies of SLC44A2*01 and SLC44A2*02were 0.812 and 0.188, respectively, and that of ITGAM*01, ITGAM*02, ITGAL*01, and ITGAL*02 were 0.9546, 0.0454, 0.2372, and 0.7628, respectively.

Conclusion

This is the first study in India to report the frequencies of HNA among blood donors. Typed neutrophil panels identified in the present study will enable us to investigate suspected cases of immune neutropenia in future.

Flow-Cytometric Analysis of HNA-2 Expression and Phenotypes Among Thai Blood Donors

BACKGROUND

Antibodies specific to human neutrophil antigen (HNA), especially HNA-2, are implicated in various conditions, including neonatal alloimmune neutropenia, febrile non-hemolytic transfusion reactions, and transfusion-related acute lung injury. The distribution of the HNA-2 phenotype frequencies in the Thai population remains unknown. This study aimed to investigate HNA-2 phenotype frequencies in Thai blood donors and to compare the relationships of sex and age with HNA-2 expression.

METHODS

EDTA blood samples were collected from 220 unrelated healthy Thai blood donors, including 150 males and 70 females, with ages ranging from 20 to 57 years. Polymorphonuclear cells were isolated and stained with monoclonal antibodies clone MEM-166 and clone 2D1, which are specific to human CD177 (HNA-2) and CD45, respectively. HNA-2 expression according to sex and age was analyzed by flow cytometry.

RESULTS

Among the 220 donors, HNA-2-positive and HNA-2-null-phenotype frequencies were 0.995 and 0.005, respectively. Mean antigen expression was significantly higher in women (71.01±15.46%) than in men (64.59±18.85%; P <0.05). No significant differences in HNA-2 expression were found between different age groups. HNA-2 phenotype frequencies were similar to those in Asian, African, American, and Brazilian populations, but were significantly different from those in eastern Japanese, Korean, and French populations (P <0.001).

CONCLUSIONS

This is the first report of HNA-2 phenotype frequencies in a Thai population, and the data will be helpful in predicting the risk of HNA-2 alloimmunization and in recruiting granulocyte panel donors.

HNA-1, -3, -4, and -5 genotyping using multiplex PCR among southern Thais: Developing continual HNA-1 null detection

BACKGROUND

Antibodies against human neutrophil antigens (HNAs) are involved in various clinical conditions including transfusion-related acute lung injury and auto/alloimmune neutropenia. We aimed to determine HNA-1, -3, -4, and -5 frequencies among southern Thais using multiplex PCR and to develop HNA-1 null detection.

METHODS

Samples obtained from 427 southern Thai blood donors were genotyped HNA-1, -3, -4, and -5 using multiplex PCR and compared their allele frequencies with those previously reported in Thai populations. HNA-1 null samples were tested by newly developed PCR-SSP and PCR-RFLP and confirmed by DNA sequencing.

RESULTS

The frequencies of FCGR3B*01, FCGR3B*02, FCGR3B*03, SLC44A2*01, SLC44A2*02, ITGAL*01, and ITGAL*02 among southern Thais differed from other Thai populations, except ITGAM*01 and ITGAM*02 frequencies. Two samples without specific fragments of FCGR3B*01, FCGR3B*02, and FCGR3B*03 tested by multiplex PCR were confirmed by PCR-RFLP to identify FCGR3B deficiency (HNA-1 null). Moreover, to reduce test steps, the newly developed PCR-SSP for FCGR3B deficiency was validated and tested in all samples and the results were in agreement with DNA sequencing.

CONCLUSIONS

This was the first study to report HNA-1, -3, -4, and -5 frequencies among southern Thais. The indeterminate results of multiplex PCR for HNA-1 genotyping led to establish HNA-1 null detection using PCR-SSP, which is simple, convenient and cost-effective and can be used to identify FCGR3B deficiency.

HNA-3a and HNA-3b antigens among 9 ethnic populations and the Han population in Southwest China

Background

Human neutrophil antigen 3 (HNA-3) is encoded by the SLC44A2 gene. Antibodies against HNAs can cause severe, often fatal, transfusion reactions, known as transfusion-related acute lung injury, and neonatal neutropenia. We explored the 2 common HNA-3 variants in 9 ethnic populations residing in Sichuan and Yunnan provinces of China as compared to the Han population.

Methods

We genotyped for SLC44A2 (rs2288904) by polymerase chain reaction sequence-based typing among blood donors, for a total of 2206 individuals in Yunnan and 376 in Sichuan.

Results

The SLC44A2*02 allele (HNA-3b antigen) frequency varied between 0.24 and 0.33 for all 9 ethnic populations in Yunnan, including Zhuang, Derung, Hani, Lisu, Bai, Miao, Dai, Naxi, and Yi. Specifically, the Yi ethnicity did not present an unusually great SLC44A2*02 frequency at any of the 4 locations examined in Yunnan. Except of the Yi ethnicity in Sichuan (0.40), the Han ethnicity, as the majority population group, had the greatest SLC44A2*02 frequency with 0.39 in Yunnan and 0.35 in Sichuan.

Conclusion

The ethnic populations in Southwest China are not at an increased risk for anti-HNA3a compared to the Han population, with the possible exception of Yi in Sichuan. Our data, however, corroborated the known high prevalence of SLC44A2*02 in Han populations. Hence, the Han populations in Yunnan, Sichuan and elsewhere in China are at a comparatively great risk for developing HNA-3a antibodies.

Full-length nucleotide sequences of 30 common SLC44A2 alleles encoding human neutrophil antigen-3

BACKGROUND

Human neutrophil antigen-3a (HNA-3a) alloantibodies can cause severe transfusion-related acute lung injury. The frequencies of the single-nucleotide polymorphisms (SNPs) indicative of the two clinically relevant HNA-3a/b antigens are known in many populations. In this study, we determined the full-length nucleotide sequence of common SLC44A2 alleles encoding the choline transporter-like protein-2 that harbors HNA-3a/b antigens.

STUDY DESIGN AND METHODS

A method was devised to determine the full-length coding sequence (CDS) and adjacent intron sequences from genomic DNA by eight polymerase chain reaction amplifications covering all 22 SLC44A2 exons. Samples from 200 African American, 96 Caucasian, two Hispanic, and four Asian blood donors were analyzed. We developed a decision tree to determine alleles (confirmed haplotypes) from the genotype data.

RESULTS

A total of 10 SNPs were detected in the SLC44A2 CDS. The noncoding sequences harbored an additional 28 SNPs (one in the 5'-untranslated region [UTR]; 23 in the introns; and four in the 3'-UTR). No SNP indicative of a nonfunctional allele was detected. The nucleotide sequences for 30 SLC44A2 alleles (haplotypes) were confirmed. There may be 66 haplotypes among the 604 chromosomes screened.

CONCLUSIONS

We found 38 SNPs, including one novel SNP, in 8192 nucleotides covering the CDS of the SLC44A2 gene among 302 blood donors. Population frequencies of these SNPs were established for African Americans and Caucasians. Because alleles encoding HNA-3b are more common than non-functional SLC44A2 alleles, we confirmed our previous postulate that African American donors are less likely to form HNA-3a antibodies compared to Caucasians.

Frequencies of human neutrophil antigen-4 and human neutrophil antigen-5 among Thai blood donors

Context:

Antibodies against human neutrophil antigens (HNAs) are implicated in immune-mediated neutropenia, transfusion-related acute lung injury and febrile transfusion reactions.

Aims:

This study aimed to determine HNA gene frequencies of the HNA-4 and HNA-5 systems among Thai populations and compare these frequencies with those previously reported for other populations.

Materials and Methods:

800 DNA samples obtained from 500 unrelated healthy blood donors from Bangkok and 300 samples from Chiang Mai, Thailand were included. Samples were typed for each HNA allele including HNA-4a, HNA-4b, HNA-5a, and HNA-5b using an in-house polymerase chain reaction with sequence-specific primer technique.

Results:

The frequencies of HNA-4a and HNA-4b alleles in central Thais were 0.975 and 0.025, respectively and for Northern Thais, their frequencies were 0.965 and 0.035, respectively. For HNA-5a and HNA-5b alleles, their frequencies were 0.771 and 0.229; 0.748, and 0.252 in central and Northern Thais, respectively. The frequencies of HNA-4 and HNA-5 systems in central Thais are closely related to those in Northern Thais (P > 0.05). However, their frequencies were different from other populations (P < 0.001), except HNA-5a and HNA-5b gene frequencies in Thais were similar to Caucasians (P > 0.05).

Conclusion:

This study could contribute to predict the risk of alloimmunization to HNA-4 and HNA-5 systems, especially in feto-maternal incompatibility in Thais.

Human neutrophil antigen profiles in Banjar, Bugis, Champa, Jawa and Kelantan Malays in Peninsular Malaysia

BACKGROUND

Human neutrophil antigens (HNA) are polymorphic and immunogenic proteins involved in the pathogenesis of neonatal alloimmune neutropenia, transfusion-related acute lung injury (TRALI) and transfusion-related alloimmune neutropenia. The characterisation of HNA at a population level is important for predicting the risk of alloimmunisation associated with blood transfusion and gestation and for anthropological studies.

MATERIALS AND METHODS

Blood samples from 192 healthy, unrelated Malays were collected and genotyped using polymerase chain reaction-sequence specific primers (HNA-1, -3, -4) and polymerase chain reaction-restriction fragment length polymorphisms (HNA-5). The group comprised 30 Banjar, 37 Bugis, 51 Champa, 39 Jawa and 35 Kelantan Malays.

RESULTS

The most common HNA alleles in the Malays studied were HNA-1a (0.641-0.765), -3a (0.676-0.867), -4a (0.943-1.000) and -5a (0.529-0.910). According to principal coordinate plots constructed using HNA allele frequencies, the Malay sub-ethnic groups are closely related and grouped together with other Asian populations. The risks of TRALI or neonatal neutropenia were not increased for subjects with HNA-1, -3 and -4 loci even for donor and recipient or pairs from different Malay sub-ethnic groups. Nonetheless, our estimates showed significantly higher risks of HNA alloimmunisation during pregnancy and transfusion between Malays and other genetically differentiated populations such as Africans and Europeans.

DISCUSSION

This study reports HNA allele and genotype frequencies for the five Malay sub-ethnic groups living in Peninsular Malaysia for the first time. These Malay sub-ethnic groups show closer genetic relationships with other Asian populations than with Europeans and Africans. The distributions of HNA alleles in other lineages of people living in Malaysia (e.g. Chinese, Indian and Orang Asli) would be an interesting subject for future study.

Risk estimation of HNA-3 incompatibility and alloimmunization in Thai populations

Severe transfusion-related acute lung injury (TRALI) is often due to antibodies in blood components directed against human neutrophil antigen (HNA)-3a. This study aimed to report the genotype frequencies of the HNA-3 system and to estimate the potential risk of HNA-3 incompatibility and alloimmunization in two Thai populations. Eight hundred DNA samples obtained from 500 unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok and 300 samples from the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand were included. HNA-3 genotyping was performed using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. The observed frequencies of the HNA-3a/3a, HNA-3a/3b, and HNA-3b/3b genotypes were 0.528, 0.380, and 0.092 in central Thais and 0.600, 0.350, and 0.050 in northern Thais, respectively. The frequencies were used to estimate HNA-3 incompatibility and risk of HNA-3a alloimmunization. The HNA-3 incompatibility in central Thais (33.28%) was higher than northern Thais (28.75%), corresponding to a significantly higher probability of HNA-3a alloimmunization (P<0.05) similar to Japanese and Chinese populations. This study showed the high risk of HNA-3 incompatibility and alloimmunization, especially in central Thai blood donors. A molecular-based identification of the HNA-3 genotype of female donors is suggested to reduce the risk of TRALI following plasma and whole blood allogeneic transfusion.

Frequency of FCGR3B alleles in Thai blood donors

Background

Human neutrophil antigens (HNAs) are involved in autoimmune and alloimmune neutropenia and transfusion-related acute lung injury. The HNA-1 system is important in immunogenetics, and allele frequencies have been described in different populations. This study investigated the frequency of FCGR3B alleles encoding HNA-1a, HNA-1b, and HNA-1c among Thai blood donors and compared these frequencies with those previously reported for other populations.

Methods

Eight hundred DNA samples obtained from unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok, and the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, were included. Samples were simultaneously typed for each FCGR3B allele using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique.

Results

The frequencies of FCGR3B*1, FCGR3B*2, and FCGR3B*3 alleles in central Thai blood donors were 0.548, 0.452, and 0.004, respectively; only FCGR3B*1 and FCGR3B*2 alleles were found in northern Thai blood donors (0.68 and 0.32, respectively). Compared with other Asian populations, central Thais had higher frequencies of the FCGR3B*2 allele (P<0.001), while the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in northern Thais were similar to those previously reported in Taiwanese and Japanese populations. In contrast, the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in the northern Thai population were statistically different from those observed in central Thai, Korean, German, and Turkish populations.

Conclusions

FCGR3B allele frequencies were significantly different between central and northern Thai blood donors. Our in-house PCR-SSP method is a simple, cost-effective, and convenient method for FCGR3B allele detection.