Human neutrophil alloantigens systems

Neonatal alloimmune neutropaenia: Experience from an Australian paediatric health service

AIM

To describe the presenting features and investigation findings in infants diagnosed with neonatal alloimmune neutropaenia (NAIN) within an Australian paediatric health network. The secondary aim was to describe the management and resolution of neutropaenia in infants with NAIN.

METHODS

A retrospective cohort study was conducted at Monash Children's Hospital, Melbourne, Australia. Infants referred to the Victorian Transplantation and Immunogenetics Service for evaluation of NAIN were identified and medical records were reviewed. Descriptive statistical analysis of infants' clinical outcomes, investigation findings and management was performed.

RESULTS

Nine infants were diagnosed with NAIN between December 2004 and June 2017. Overall incidence of NAIN was around 1 per 10 000 births. Median gestational age was 38 (range 35-40) weeks and birthweight was 2920 (2300-4445) g. Median age at NAIN work-up was 7 (2-33) days. Prior to investigation for NAIN, median absolute neutrophil count was 0.2 (0.01-0.6) × 10⁹ cells/L. The post-natal ward was the source of presentation in most infants (78%). All except one infant were admitted to a neonatal unit and commenced on intravenous antibiotics (89%). Six infants were asymptomatic but received antibiotics for risk of infection (75%). Granulocyte-colony stimulating factor was administered to 44% of infants due to neutropaenia with presumed or confirmed infection. NAIN resolved at median age of 32 (6-200) days.

CONCLUSIONS

Infants with NAIN frequently presented with severe, unexpected neutropaenia without major infection. Intravenous antibiotic therapy and granulocyte-colony stimulating factor use was common in this cohort.

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.

A study of human neutrophil antigen genotype frequencies in Hong Kong

BACKGROUND

Alloantibodies against human neutrophil antigens (HNA) are associated with a variety of clinical conditions. Over the past decade, the allelic and genotypic frequencies of the five HNA systems have been evaluated. Although the HNA system is less polymorphic than human leukocyte antigens (HLA), significant differences in the genotypic and allele frequencies still exist in different populations, even those living in close proximity.

OBJECTIVES

To delineate HNA genotypic and allele frequencies to provide vital information on estimating the risk of HNA-associated diseases for our local population.

METHODS

Using a validated, in-house-developed assay, genotyping for HNA-1, HNA-3, HLA-4 and HNA-5 was performed on 300 samples from Chinese blood donors from Hong Kong. In addition, the frequency of the HNA-2 c.843A > T allele was also determined.

RESULTS

The allele frequencies of HNA-1a, -1b and -1c alleles were 67·8, 31·5 and 0%, respectively, whereas the frequencies of HNA-3a and HNA-3b were 71·0 and 29·0%, respectively. The frequencies of HNA-4a and -4b alleles were 99·5 and 0·5%, respectively, and for HNA-5a and -5b, alleles were 85·2 and 14·8%, respectively. Homozygotes for the HNA-2 c.843 TT variant were absent in our population, whereas only <4% of the population were c.843AT heterozygote carriers.

CONCLUSIONS

This is the first study to define HNA genotype and allele frequencies using a validated modified in-house PCR-SSP method in the Hong Kong Chinese blood donor population. Our approach provides a cost-effective assay for conducting routine HNA typing and facilitates the incorporation of these assays into routine clinical service. Our results are comparable with those reported in the Guangzhou Chinese population, but the allele frequencies in our Hong Kong Chinese population are significantly different from the reported European frequencies, confirming that a geographical difference exists for HNA allele frequencies.

Recent advances in understanding neutrophils

Neutrophils have long been regarded as key effectors of the innate immune response during acute inflammation. Recent evidence has revealed a greater functional diversity for these cells than previously appreciated, expanding roles for neutrophils in adaptive immunity and chronic pathologies. In this review, we summarize some of the evolving paradigms in the neutrophil field and highlight key advances that have contributed to our understanding of neutrophil behavior and function in vivo. We examine the concept of neutrophil subsets and polarization, we discuss novel immunomodulatory roles for neutrophils in shaping the immune response, and, finally, we identify technical advances that will further enhance our ability to track the function and fate of neutrophils.

Heterogeneity of Human Neutrophil CD177 Expression Results from CD177P1 Pseudogene Conversion

Most humans harbor both CD177neg and CD177pos neutrophils but 1-10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1), which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation.

Crucial Role of Lateral Size for Graphene Oxide in Activating Macrophages and Stimulating Pro-inflammatory Responses in Cells and Animals

Graphene oxide (GO) is increasingly used in biomedical applications because it possesses not only the unique properties of graphene including large surface area and flexibility but also hydrophilicity and dispersibility in aqueous solutions. However, there are conflicting results on its biocompatibility and biosafety partially due to large variations in physicochemical properties of GO, and the role of these properties including lateral size in the biological or toxicological effects of GO is still unclear. In this study, we focused on the role of lateral size by preparing a panel of GO samples with differential lateral sizes using the same starting material. We found that, in comparison to its smaller counterpart, larger GO showed a stronger adsorption onto the plasma membrane with less phagocytosis, which elicited more robust interaction with toll-like receptors and more potent activation of NF-κB pathways. By contrast, smaller GO sheets were more likely taken up by cells. As a result, larger GO promoted greater M1 polarization, associated with enhanced production of inflammatory cytokines and recruitment of immune cells. The in vitro results correlated well with local and systemic inflammatory responses after GO administration into the abdominal cavity, lung, or bloodstream through the tail vein. Together, our study delineated the size-dependent M1 induction of macrophages and pro-inflammatory responses of GO in vitro and in vivo. Our data also unearthed the detailed mechanism underlying these effects: a size-dependent interaction between GO and the plasma membrane.

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.

Evaluation of HNA-expressing cell line-based antigen capture systems and a solid-phase system for detecting HNA-1a antibodies

Granulocyte immunofluorescence and granulocyte agglutination tests are standard methods for detecting human neutrophil antigen (HNA) antibodies (Abs); however, these require a typed panel of neutrophils, which can be time-consuming to develop, and it remains difficult to determine antibody specificity in some cases. We established and evaluated four detection systems for HNA-1a Abs based on an HNA-1a-expressing cell line (KY cells) and antigen capture. We additionally evaluated a commercial solid-phase system. Eleven HNA-1a antibody-positive samples, including the World Health Organization Reference Reagent, and 40 serum samples derived from male blood donors were used as positive and negative control samples, respectively. Although specificity was >0.90 in all systems evaluated, the sensitivity varied among the systems. The KY cell-based monoclonal antibody specific immobilisation of granulocyte antigens (KY-MAIGA) system using certain, but not all, monoclonal Abs, and the solid-phase system revealed higher sensitivity than other systems. In conclusion, the KY-MAIGA and commercial solid-phase systems were superior in terms of specific and sensitive detection of HNA-1a Abs.

FCGR3B gene frequencies among ethnic Thai blood donors from a regional hospital in Eastern Thailand

The FCGR3B gene encodes three human neutrophil antigens which consist of HNA-1a, HNA-1b, and HNA-1c. These antigens are encoded by three alleles in the FCGR3B locus: FCGR3B*01, FCGR3B*02, and FCGR3B*03 alleles, respectively. The frequencies of FCGR3B alleles have been reported in different ethnic populations. This study compared the FCGR3B gene frequencies among 230 unrelated healthy Eastern Thai blood donors in Rayong hospital with the previously published studies. The polymerase chain reaction-sequence-specific primers method was performed to determine FCGR3B genotypes. The results showed that the allele frequencies of FCGR3B*01, FCGR3B*02, and FCGR3B*03 were 0.722, 0.274, and 0.009, respectively. The FCGR3B*01 and FCGR3B*02 frequencies found in the Eastern Thais were similar to the previous reports investigating in Northern Thais, Chinese Han, Taiwanese, and Japanese populations. Interestingly, our data showed statistically significant difference (P < 0.05) to Central Thais, Korean, Indian, Turkish, Australian, Tunisian, American, German, and Italian populations. In addition, one FCGR3Bnull , which represents a gene deletion, was also found in this study. This information is important not only for the assessment of neutrophil antibody-mediated clinical conditions and for disease association studies but also for anthropological studies.

Genotyping of human neutrophil antigens by polymerase chain reaction sequence-based typing

BACKGROUND

Genotyping for human neutrophil antigen (HNA) systems is required in the investigation of disorders involving alloimmunisation to HNA. We established a polymerase chain reaction sequence-based typing method for genotyping HNA and determined the genotype and allele frequencies of HNA in the Zhejiang Han population of China.

MATERIALS AND METHODS

Four hundred, healthy unrelated Zhejiang Han individuals were recruited. Specific primers for HNA were designed and the polymerase chain reaction amplification conditions were optimised. Amplification amplicons were purified with enzyme digestion and then sequenced.

RESULTS

The frequencies of the FCGR3B*01 and FCGR3B*02 alleles were 0.613 and 0.387; no FCGR3B*03 allele was found. The frequencies of the SLC44A2*1 and SLC44A2*2 alleles were 0.654 and 0.346, respectively, while the frequencies of the ITGAL*1 (HNA-5a) and ITGAL*2 (HNA-5b) alleles were 0.896 and 0.104. Only ITGAM*1 (HNA-4a) allele was found in this study. Six single nucleotide polymorphisms were confirmed on sequenced regions separate from HNA polymorphisms, including FCGR3B (IVS3+39G>A and IVS3+52G>A), CD177(172A>G), SLC44A2 (IVS5-44A>G and IVS7-15T>C) and ITGAM (IVS3+118T>C).

DISCUSSION

The polymerase chain reaction sequence-based typing method for genotyping HNA is reliable. These data of HNA alleles frequencies could contribute to the analysis of alloimmunisation to HNA in China.

Genotyping of human neutrophil antigens (HNA) from whole genome sequencing data

Background

Neutrophil antigens are involved in a variety of clinical conditions including transfusion-related acute lung injury (TRALI) and other transfusion-related diseases. Recently, there are five characterized groups of human neutrophil antigen (HNA) systems, the HNA1 to 5. Characterization of all neutrophil antigens from whole genome sequencing (WGS) data may be accomplished for revealing complete genotyping formats of neutrophil antigens collectively at genome level with molecular variations which may respectively be revealed with available genotyping techniques for neutrophil antigens conventionally.

Results

We developed a computing method for the genotyping of human neutrophil antigens. Six samples from two families, available from the 1000 Genomes projects, were used for a HNA typing test. There are 500 ~ 3000 reads per sample filtered from the adopted human WGS datasets in order for identifying single nucleotide polymorphisms (SNPs) of neutrophil antigens. The visualization of read alignment shows that the yield reads from WGS dataset are enough to cover all of the SNP loci for the antigen system: HNA1, HNA3, HNA4 and HNA5. Consequently, our implemented Bioinformatics tool successfully revealed HNA types on all of the six samples including sequence-based typing (SBT) as well as PCR sequence-specific oligonucleotide probes (SSOP), PCR sequence-specific primers (SSP) and PCR restriction fragment length polymorphism (RFLP) along with parentage possibility.

Conclusions

The next-generation sequencing technology strives to deliver affordable and non-biased sequencing results, hence the complete genotyping formats of HNA may be reported collectively from mining the output data of WGS. The study shows the feasibility of HNA genotyping through new WGS technologies. Our proposed algorithmic methodology is implemented in a HNATyping software package with user’s guide available to the public at http://sourceforge.net/projects/hnatyping/.

Human neutrophil alloantigen genotype frequencies in Thai blood donors

BACKGROUND

Antibodies to human neutrophil antigens (HNA) can cause transfusion reactions, as well as autoimmune and neonatal neutropenia. This study is the first to report the frequencies of human neutrophil antigen genotypes in the Thai population.

MATERIALS AND METHODS

Three hundred unrelated, healthy Thai blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok, Thailand were typed for HNA-1a, -1b, -1c, -3a, -3b and -4a using polymerase chain reaction with sequence-specific primers. Moreover, HNA-5a genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

The gene frequencies of HNA-1a, -1b and -1c were 0.470, 0.530 and 0.005, respectively. The frequencies of HNA-3a and -3b were 0.490 and 0.510, respectively. Additionally, the HNA-4a+/+ and HNA-4a+/- genotype frequencies were 0.947 and 0.053, respectively. The frequencies of HNA-5a+/+, HNA-5a+/- and HNA-5a-/- genotypes were 0.641, 0.297 and 0.062, respectively. Compared with other Asian populations, Thais have higher frequencies of HNA-1b (P<0.001). On the other hand, the frequency of HNA-5a observed in Thais is lower than that reported among Koreans (P<0.001).

DISCUSSION

These findings suggest that Thais would be more susceptible to HNA-1b alloimmunisation. Furthermore, our results could establish a useful human neutrophil antigen donor file to provide more effective transfusion of blood and blood components.

Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils

Hematopoietic cells, including lymphoid and myeloid cells, can develop into phenotypically distinct 'subpopulations' with different functions. However, evidence indicates that some of these subpopulations can manifest substantial plasticity (that is, undergo changes in their phenotype and function). Here we focus on the occurrence of phenotypically distinct subpopulations in three lineages of myeloid cells with important roles in innate and acquired immunity: macrophages, mast cells and neutrophils. Cytokine signals, epigenetic modifications and other microenvironmental factors can substantially and, in some cases, rapidly and reversibly alter the phenotype of these cells and influence their function. This suggests that regulation of the phenotype and function of differentiated hematopoietic cells by microenvironmental factors, including those generated during immune responses, represents a common mechanism for modulating innate or adaptive immunity.

The frequencies of human neutrophil alloantigens in the Chinese Han population of Guangzhou

BACKGROUND

Antibodies against polymorphic structures on human neutrophil antigens (HNAs) play a role in alloimmune-mediated neutropenia and are the leading cause of antibody-mediated transfusion-related acute lung injury (TRALI). This study aimed to determine the frequencies of HNAs in the major Han ethnic group living in Guangdong Province, Southern China.

STUDY DESIGN AND METHODS

A total of 493 healthy Chinese Han blood donors from Guangzhou were recruited. DNA samples were isolated and typed for all five HNA-1, -2, -3, -4, and -5 systems using allele-specific polymerase chain reaction approaches. Results were compared with available data from other Chinese cohorts and other Asian and Caucasian populations.

RESULTS

In this cohort, the gene frequency for HNA-1a (0.667) was approximately twice that of HNA-1b (0.333). In contrast to Caucasian populations, HNA-1a represents the most frequent allele in the Chinese population. HNA-3 system genotyping revealed comparable frequencies for HNA-3a (0.738) and -3b (0.262) in Chinese and Caucasian populations. Homozygous HNA-3 bb individuals were found in 5.64% of our cohort. HNA-4 genotyping revealed no HNA-4 bb homozygous individuals. In contrast, HNA-5 bb homozygous individuals represented 2.43% of the population. Typing the HNA-2 system for the single-nucleotide polymorphism C42G showed that the C-allele (69%) is overrepresented and is associated with an increased number of HNA-2a-positive neutrophil subpopulations.

CONCLUSION

This study describes for the first time the frequencies of all HNA systems, including the newly identified HNA-3, within one cohort of Chinese Han population. Comparison with Caucasian populations may allow assessment of anti-HNA alloimmunization and estimation of alloimmune neutropenia and TRALI incidence in Chinese populations.

Mycobacterium bovis-BCG vaccination induces specific pulmonary transcriptome biosignatures in mice

Background

In the present study, we applied microarray technology to define biosignatures by microarray transcriptome analysis in lung and spleen samples after BCG vaccination and M. bovis infection of BALB/c mice. The aims were two-fold, namely to define biosignatures that could predict vaccine success before challenge, and biomarker patterns that correlated with anamnestic protective responses following exposure to virulent M. bovis. Further, these biosignatures should be detectable without in vitro antigenic challenge.

Principal Findings

After BCG vaccination, we defined a specific pulmonary gene expression signature related to the connective tissue development and function network that predicted vaccine success before M. bovis challenge. In addition, a Th17-related cytokine profile was found that correlated with vaccine-induced protective immunity following infection with virulent M. bovis in the lung as well as additional genes that were up-regulated in the spleens of vaccinated animals post-infection related to neutrophil biology and inflammation.

Conclusions

This study has therefore prioritized both biomarkers predicting vaccination success before challenge and bio-signatures that are potentially associated with protective immune responses that will be useful to evaluate future vaccine candidates.