Association of Blood Group Antigen CD59 with Disease

In 2014, the membrane-bound protein CD59 became a blood group antigen. CD59 has been known for decades as an inhibitor of the complement system, located on erythrocytes and on many other cell types. In paroxysmal nocturnal haemoglobinuria (PNH), a stem cell clone with acquired deficiency to express GPI-anchored molecules, including the complement inhibitor CD59, causes severe and life-threatening disease. The lack of CD59, which is the only membrane-bound inhibitor of the membrane attack complex, contributes a major part of the intravascular haemolysis observed in PNH patients. This crucial effect of CD59 in PNH disease prompted studies to investigate its role in other diseases. In this review, the role of CD59 in inflammation, rheumatic disease, and age-related macular degeneration is investigated. Further, the pivotal role of CD59 in PNH and congenital CD59 deficiency is reviewed.

Application of Blood Group Genotyping by Next-Generation Sequencing in Various Immunohaematology Cases

<b><i>Background:</i></b> Next-generation sequencing (NGS) technology has been recently introduced into blood group genotyping; however, there are few studies using NGS-based blood group genotyping in real-world clinical settings. In this study, we applied NGS-based blood group genotyping into various immunohaematology cases encountered in routine clinical practice. <b><i>Methods:</i></b> This study included 4 immunohaematology cases: ABO subgroup, ABO chimerism, antibody to a high-frequency antigen (HFA), and anti-CD47 interference. We designed a hybridization capture-based NGS panel targeting 39 blood group-related genes and applied it to the 4 cases. <b><i>Results:</i></b> NGS analysis revealed a novel intronic variant (NM_020469.3:c.29-10T&#x3e;G) in a patient with an A_el phenotype and detected a small fraction of <i>ABO</i>*<i>A1.02</i> (approximately 3–6%) coexisting with the major genotype <i>ABO</i>*<i>B.01</i>/<i>O.01.02</i> in dizygotic twins. In addition, NGS analysis found a homozygous stop-gain variant (NM_004827.3:c.376C&#x3e;T, p.Gln126*; <i>ABCG2</i>*<i>01N.01</i>) in a patient with an antibody to an HFA; consequently, this patient’s phenotype was predicted as Jr(a−). Lastly, blood group phenotypes predicted by NGS were concordant with those determined by serology in 2 patients treated with anti-CD47 drugs. <b><i>Conclusion:</i></b> NGS-based blood group genotyping can be used for identifying <i>ABO</i> subgroup alleles, low levels of blood group chimerism, and antibodies to HFAs. Furthermore, it can be applied to extended blood group antigen matching for patients treated with anti-CD47 drugs.

ABO blood group antigen therapy: a potential new strategy against solid tumors

The economic burden of tumors is increasing, so there is an urgent need to develop new therapies for their treatment. Killing tumors by activating complement is an effective strategy for the treatment. We used the ABO blood group system and the corresponding antibodies to activate the killer cell capacity of the complement system. After the construction of a mouse model containing blood group A antibodies and inoculating colorectal cancer and breast cancer cells into the axillae of the mice, intratumoural injection using a lentivirus carrying a blood group antigen as a drug significantly reduced the tumor volume of the mice. Compared with the control group, the content of the C5b-9 complement membrane attack complex in the tumors of mice treated with the blood group A antigen was significantly increased, and the proportion of NK cells was also significantly increased. In vitro cell-based experiments proved that tumor cells expressing blood group A antigens showed significantly inhibited cell proliferation when added to serum containing blood group A antibodies. These results all prove that the ABO blood group antigen may become a powerful tool for the treatment of tumors in patients.

Molecular Epidemiology of Sapovirus in Children Living in the Northwest Amazon Region

Sapovirus is an important etiological agent of acute gastroenteritis (AGE), mainly in children under 5 years old living in lower-income communities. Eighteen identified sapovirus genotypes have been observed to infect humans. The aim of this study was to identify sapovirus genotypes circulating in the Amazon region. Twenty-eight samples were successfully genotyped using partial sequencing of the capsid gene. The genotypes identified were GI.1 (n = 3), GI.2 (n = 7), GII.1 (n = 1), GII.2 (n = 1), GII.3 (n = 5), GII.5 (n = 1), and GIV.1 (n = 10). The GIV genotype was the most detected genotype (35.7%, 10/28). The phylogenetic analysis identified sapovirus genotypes that had no similarity with other strains reported from Brazil, indicating that these genotypes may have entered the Amazon region via intense tourism in the Amazon rainforest. No association between histo-blood group antigen expression and sapovirus infection was observed.

Broadly cross-reactive human antibodies that inhibit genogroup I and II noroviruses

The rational development of norovirus vaccine candidates requires a deep understanding of the antigenic diversity and mechanisms of neutralization of the virus. Here, we isolate and characterize a panel of broadly cross-reactive naturally occurring human monoclonal IgMs, IgAs and IgGs reactive with human norovirus (HuNoV) genogroup I or II (GI or GII). We note three binding patterns and identify monoclonal antibodies (mAbs) that neutralize at least one GI or GII HuNoV strain when using a histo-blood group antigen (HBGA) blocking assay. The HBGA blocking assay and a virus neutralization assay using human intestinal enteroids reveal that the GII-specific mAb NORO-320, mediates HBGA blocking and neutralization of multiple GII genotypes. The Fab form of NORO-320 neutralizes GII.4 infection more potently than the mAb, however, does not block HBGA binding. The crystal structure of NORO-320 Fab in complex with GII.4 P-domain shows that the antibody recognizes a highly conserved region in the P-domain distant from the HBGA binding site. Dynamic light scattering analysis of GII.4 virus-like particles with mAb NORO-320 shows severe aggregation, suggesting neutralization is by steric hindrance caused by multivalent cross-linking. Aggregation was not observed with the Fab form of NORO-320, suggesting that this clone also has additional inhibitory features.

You can run, but you can’t hide - A bitemark analysis

All names and places have been changed to protect innocent victims in this case report. A young woman was returning home after work when she was accosted by a man wielding a knife. She was dragged into a nearby bush where the suspect attempted to rape her. She put up a substantial fight and was able to flee the scene. She went directly to the nearest police station to report the case. She was asked by the police to accompany them in the hope that she might recognise the suspect at the local taxi rank, which was near the scene of the crime. She did in fact recognise the suspect who was duly arrested. He denied any knowledge of the crime for which he was being apprehended. The victim informed the police that she had remembered biting the suspect on his right shoulder during the attack and ensuing struggle. The suspect was asked to roll up his right sleeve where a possible bitemark wound was observed. The suspect was taken into custody for further investigations. Fortunately, the police officer in charge of the case had attended a lecture on bitemarks given by the second author some weeks before the incident and was therefore well-versed in the protocol for the collection of evidence in a bitemark case. The officer arranged that photographs and impressions of the possible bitemark were taken for forensic analysis. Unfortunately, swobs of the bitemark were not conducted, therefore DNA and ABO blood group antigen analysis could not be performed. Impressions of the victim’s dentition were also taken from which plaster models were constructed. All dental materials used in this case were mixed according to the manufacturer’s instructions and were within their expiry dates. This evidence was submitted to the forensic odontology unit at the University of Pretoria for examination and comparative analysis