Red blood cell blood group A antigen level affects the ability of heparin and PfEMP1 antibodies to disrupt Plasmodium falciparum rosettes.

BACKGROUND: The histo-blood group ABO system has been associated with adverse outcomes in COVID-19, thromboembolic diseases and Plasmodium falciparum malaria. An integral part of the severe malaria pathogenesis is rosetting, the adherence of parasite infected red blood cells (RBCs) to uninfected RBCs. Rosetting is influenced by the host's ABO blood group (Bg) and rosettes formed in BgA have previously been shown to be more resilient to disruption by heparin and shield the parasite derived surface antigens from antibodies. However, data on rosetting in weak BgA subgroups is scarce and based on investigations of relatively few donors. METHODS: An improved high-throughput flow cytometric assay was employed to investigate rosetting characteristics in an extensive panel of RBC donor samples of all four major ABO Bgs, as well as low BgA expressing samples. RESULTS: All non-O Bgs shield the parasite surface antigens from strain-specific antibodies towards P. falciparum erythrocyte membrane protein 1 (PfEMP1). A positive correlation between A-antigen levels on RBCs and rosette tightness was observed, protecting the rosettes from heparin- and antibody-mediated disruption. CONCLUSIONS: These results provide new insights into how the ABO Bg system affects the disease outcome and cautions against interpreting the results from the heterogeneous BgA phenotype as a single group in epidemiological and experimental studies.

No increase in anti-A isohemagglutinin titer after SARS-CoV-2 infection: A retrospective cohort analysis of group O apheresis platelet donors.

The risk of a hemolytic reaction during the transfusion of ABO non-identical PC is determined by the presence of natural anti-A IgM antibodies, the titer of which may increase after infections. The aim of the study was to evaluate the titer of anti-A isohemagglutinins in platelet concentrate (PC) obtained by apheresis from group O donors who experienced SARS-CoV-2 infection, and to compare the titer before and after infection. A retrospective single-center analysis of 21 PC donors with a previous COVID-19 history was performed. The results showed neither a statistically important increase in the anti-A IgM antibody titers nor a significant correlation between the anti-A IgM antibody level and anti-SARS-CoV-2S1 antibody titer in the donors with an asymptomatic or mild COVID-19. Further population-based studies on anti-A titers are necessary for a comprehensive assessment of this phenomenon.

Characteristics of coronavirus disease 19 convalescent plasma donors and donations in the New York metropolitan area.

BACKGROUND: Convalescent plasma (CP) is an important initial treatment in pandemics and the New York (NY) metropolitan area is likely to remain a hotspot for collection and distribution of such units. This study reports characteristics of coronavirus disease 19 CP (CCP) donors and their donations to the New York Blood Center (NYBC). STUDY DESIGN AND METHODS: All CCP data from our first day of collection on March 26th through July 7th, 2020 are included in this retrospective analysis. Donor and donation data were extracted from NYBC electronic databases. SARS-CoV-2 antibody testing was initially performed by the NY State Department of Health, and later by NYBC using Ortho and Abbott platforms. RESULTS: CCP donor age and ABO distributions were consistent with reported lower COVID-19 susceptibility in O blood types. CCP versus whole blood donors had similar on-site deferrals, but higher post-donation deferral rates. CCP versus routine plasmapheresis donations had higher vasovagal reactions but similar product rejection rates. Changes in antibody (Ab) test platforms resulted in significant changes in the percent of donors regarded as antibody positive. Donor correlates with higher anti-spike total Ig S/CO ratios were Hispanic ethnicity, overweight body mass index, and longer symptom duration; and with higher anti-nucleocapsid IgG S/CO ratios were male gender, older age, Hispanic ethnicity, and fewer days between symptom onset and first donation. DISCUSSION: We identify donor characteristics not previously reported to correlate with Ab titer. Our analysis should assist with donor outreach strategies, blood center operating logistics, and recruitment of high titer donors.

Blood system ABO antigens as risk factor for severity of SARS-CoV-2 infection.

INTRODUCTION: Whether there is an influence of the ABO blood system on SARS-CoV-2 infection is unknown. OBJECTIVE: To analyze if there is an association between the ABO system antigens and susceptibility to and severity of SARS-CoV-2 infection. MATERIAL AND METHODS: The frequency of ABO system antigens was compared in 73 confirmed cases of SARS-CoV-2 infection and 52 clinically healthy donors. Infection severity was assessed by comparing the frequency of antigens by disease severity and mortality. RESULTS: The risk of suffering from SARS-CoV-2 infection increases in subjects with A vs. non-A antigen (OR = 1.45; 95 % CI: 1.061-1.921). Blood phenotype O reduces the risk of SARS-CoV-2 infection (OR = 0.686; 95 % CI: 0.522-0.903). No differences were found regarding disease severity. In critically ill patients, the risk of mortality increased in subjects with A vs. non-A antigen (OR = 3.34; 95 % CI: 1.417-8.159). CONCLUSION: Blood group A is a risk factor for SARS-CoV-2 infection, but not for disease severity, although in critically ill patients it is a risk factor for mortality.

INTRODUCCIÓN: Se desconoce si existe una influencia del sistema sanguíneo ABO en susceptibilidad y gravedad de la enfermedad. OBJETIVO: Analizar si existe una asociación entre los antígenos del sistema ABO y la susceptibilidad y gravedad de la infección por SARS-CoV-2. MATERIAL Y MÉTODOS: Se compararon las frecuencias de los antígenos del sistema ABO en 73 casos confirmados de infección por SARS-CoV-2 y 52 donadores clínicamente sanos. La gravedad de la infección se evaluó comparando la frecuencia de los antígenos por gravedad de la enfermedad y la mortalidad. RESULTADOS: El riesgo de padecer infección por SARS-CoV-2 se incrementa en sujetos con antígeno A vs los no-A (OR=1.45; IC95 %:1.061-1.921). El fenotipo sanguíneo O disminuye el riesgo de padecer infección por SARS-CoV-2 (OR=0.686; IC95 %: 0.522-0.903). No se encontraron diferencias entre la gravedad de la enfermedad. En los pacientes graves, el riesgo de mortalidad se incrementó en sujetos con antígeno A vs los no-A (OR= 3.34; IC95 %: 1.417-8.159). CONCLUSIÓN: El grupo sanguíneo A es un factor de riesgo para padecer infección por SARS-CoV-2, no así en la gravedad de la enfermedad, pero en los pacientes graves fue un factor de riesgo para la mortalidad.

Lewis and ABO histo-blood types and the secretor status of patients hospitalized with COVID-19 implicate a role for ABO antibodies in susceptibility to infection with SARS-CoV-2.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) targets the respiratory and gastric epithelium, causing coronavirus disease 2019 (COVID-19). Tissue antigen expression variations influence host susceptibility to many infections. This study aimed to investigate the closely linked Lewis (FUT3) and ABO histo-blood types, including secretor (FUT2) status, to infections with SARS-CoV-2 and the corresponding severity of COVID-19. STUDY DESIGN AND METHODS: Patients (Caucasians, n = 338) were genotyped for ABO, FUT3, and FUT2, and compared to a reference population of blood donors (n = 250,298). The association between blood types and severity of COVID-19 was addressed by dividing patients into four categories: hospitalized individuals in general wards, patients admitted to the intensive care unit with and without intubation, and deceased patients. Comorbidities were considered in subsequent analyses. RESULTS: Patients with blood type Lewis (a-b-) or O were significantly less likely to be hospitalized (odds ratio [OR] 0.669, confidence interval [CI] 0.446-0.971, OR 0.710, CI 0.556-0.900, respectively), while type AB was significantly more prevalent in the patient cohort (OR 1.519, CI 1.014-2.203). The proportions of secretors/nonsecretors, and Lewis a+ or Lewis b+ types were consistent between patients and controls. The analyzed blood groups were not associated with the clinical outcome as defined. DISCUSSION: Blood types Lewis (a-b-) and O were found to be protective factors, whereas the group AB is suggested to be a risk factor for COVID-19. The antigens investigated may not be prognostic for disease severity, but a role for ABO isoagglutinins in SARS-CoV-2 infections is strongly suggested.

Ubiquitous convalescent plasma: An artificial universal plasma for COVID-19 patients.

OBJECTIVES AND BACKGROUND: In December 2019, the first case of COVID-19 was reported in Wuhan, China. Its causative virus, is a novel strain of RNA viruses with high mortality rate. There is no definitive treatment, but among available approaches the use of recovered patients' plasma containing specific antibodies can enhance the immune response against coronavirus. However, the dearth of eligible donors and also ABO incompatibility in plasma transfusion, have limited this therapeutic method. Therefore, it is highly desirable to introduce a simple procedure that allows efficient reduction or even removal of natural ABO antibodies. Accordingly, we aimed to evaluate a RBC-mediated adsorption technique that reduces the titer of the mentioned antibodies in plasma. METHODS/MATERIALS: This experimental study was conducted in Kerman University of Medical Sciences, Kerman, Iran. The pre- and post-incubation antibody titers of 168 plasma samples were determined. For incubation, each plasma sample was exposed (60 min) to different percentages of RBCs at room temperature or 4 °C. RESULTS: The results evidenced that both the concentration of RBCs and temperature had significant decreasing effects on antibody titer (P < 0.001) and all concentrations significantly reduced titer. Compared to RT, 4 °C further reduced the antibody titer. Overall, the best incubation condition for reducing antibody titer in all blood groups was 4 °C and 2% RBCs concentration. CONCLUSION: The presented adsorption procedure is able to produce universal plasma (we call it Ubiquitous Convalescent Plasma) with a non-immunogenic level of ABO mismatch antibodies which can be used for COVID-19 patients with any type of blood group with desirable simplicity, feasibility, and efficacy.

Production of anti-SARS-CoV-2 hyperimmune globulin from convalescent plasma.

BACKGROUND: In late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus emerged in China and quickly spread into a worldwide pandemic. Prior to the development of specific drug therapies or a vaccine, more immediately available treatments were sought including convalescent plasma. A potential improvement from convalescent plasma could be the preparation of anti-SARS-CoV-2 hyperimmune globulin (hIVIG). STUDY DESIGN AND METHODS: Convalescent plasma was collected from an existing network of plasma donation centers. A caprylate/chromatography purification process was used to manufacture hIVIG. Initial batches of hIVIG were manufactured in a versatile, small-scale facility designed and built to rapidly address emerging infectious diseases. RESULTS: Processing convalescent plasma into hIVIG resulted in a highly purified immunoglobulin G (IgG) product with more concentrated neutralizing antibody activity. hIVIG will allow for the administration of greater antibody activity per unit of volume with decreased potential for several adverse events associated with plasma administration. IgG concentration and IgG specific to SARS-CoV-2 were increased over 10-fold from convalescent plasma to the final product. Normalized enzyme-linked immunosorbent assay activity (per mg/ml IgG) was maintained throughout the process. Protein content in these final product batches was 100% IgG, consisting of 98% monomer and dimer forms. Potentially hazardous proteins (IgM, IgA, and anti-A, anti-B, and anti-D) were reduced to minimal levels. CONCLUSIONS: Multiple batches of anti-SARS-CoV-2 hIVIG that met regulatory requirements were manufactured from human convalescent plasma. The first clinical study in which the hIVIG will be evaluated will be Inpatient Treatment with Anti-Coronavirus Immunoglobulin (ITAC) [NCT04546581].

The Role of Immunogenetics in COVID-19.

Coronavirus disease 2019 (COVID-19) is induced by SARS-CoV-2 and may arise as a variety of clinical manifestations, ranging from an asymptomatic condition to a life-threatening disease associated with cytokine storm, multiorgan and respiratory failure. The molecular mechanism behind such variability is still under investigation. Several pieces of experimental evidence suggest that genetic variants influencing the onset, maintenance and resolution of the immune response may be fundamental in predicting the evolution of the disease. The identification of genetic variants behind immune system reactivity and function in COVID-19 may help in the elaboration of personalized therapeutic strategies. In the frenetic look for universally shared treatment plans, those genetic variants that are common to other diseases/models may also help in addressing future research in terms of drug repurposing. In this paper, we discuss the most recent updates about the role of immunogenetics in determining the susceptibility to and the history of SARS-CoV-2 infection. We propose a narrative review of available data, speculating about lessons that we have learnt from other viral infections and immunosenescence, and discussing what kind of aspects of research should be deepened in order to improve our knowledge of how host genetic variability impacts the outcome for COVID-19 patients.

Covid-19 and blood groups: ABO antibody levels may also matter.

BACKGROUND: Susceptibility to Covid-19 has been found to be associated with the ABO blood group, with O type individuals being at a lower risk. However, the underlying mechanism has not been elucidated. Here, we aimed to test the hypothesis that Covid-19 patients might have lower levels of ABO antibodies than non-infected individuals as they could offer some degree of protection. METHODS: After showing that the viral spike protein harbors the ABO glycan epitopes when produced by cells expressing the relevant glycosyltransferases, like upper respiratory tract epithelial cells, we enrolled 290 patients with Covid-19 and 276 asymptomatic controls to compare their levels of natural ABO blood group antibodies. RESULTS: We found significantly lower IgM anti-A + anti-B agglutination scores in blood group O patients (76.93 vs 88.29, P-value = 0.034) and lower levels of anti-B (24.93 vs 30.40, P-value = 0.028) and anti-A antibodies (28.56 vs 36.50, P-value = 0.048) in blood group A and blood group B patients, respectively, compared to controls. CONCLUSION: In this study, we showed that ABO antibody levels are significantly lower in Covid-19 patients compared to controls. These findings could indicate that patients with low levels of ABO antibodies are at higher risk of being infected.

ABO phenotype and SARS-CoV-2 infection: Is there any correlation?

COVID-19 is the currently evolving viral disease worldwide. It mainly targets the respiratory organs, tissues and causes illness. A plethora of studies has been performing to bring proper treatment and prevent people from the infection. Likewise, susceptibility to some infectious diseases has been associated with blood group phenotypes. The co-relationship of blood group with the occurrence of SARS-CoV-2 infection and death has been examined in numerous studies. This review explained the described studies regarding the correlation of blood group and the other essential factors with COVID-19.

COVID-19 in the Developing World: Is the Immune Response to α-Gal an Overlooked Factor Mitigating the Severity of Infection?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which has affected millions of people worldwide. Considerably lower prevalence and fatality rates resulting from COVID-19 are reported in Africa and Asia than in the industrialized world. In this Viewpoint, we discuss the possibility that this intriguing phenomenon could be, among other factors, due to protective immunity of the oligosaccharide galactose-α-1,3-galactose (α-Gal). The α-Gal immunity induced by gut microbiota that express the same glycan modification may prevent COVID-19 through the activation of different mechanisms involved in SARS-CoV-2 neutralization and the downregulation of the inflammatory response in the lungs of infected patients.

Efficacy of convalescent plasma according to blood groups in COVID-19 patients

Background/aim: In this study, we aim to investigate the efficacy of convalescent plasma (CP) according to blood groups (BGs) in the treatment of critically ill patients diagnosed with COVID-19. Materials and methods: Twenty-eight critically ill and laboratory-confirmed COVID-19 patients who were admitted to the intensive care unit (ICU) of Sakarya University, Medical Faculty were included in the study. Patients were divided into 2 groups: patients who received anti-A antibody (Ab) containing CP (BG O and B) and those who did not receive CP containing anti-A Ab (BG A and AB). Results: Among the 28 patients, 13 patients received anti-A Ab containing CP (BG; B: 6, O: 7) and 15 patients did not receive anti-A Ab CP (BG; A: 13, AB: 2). Duration in ICU, the rates of mechanical ventilation (MV) support and vasopressor support, the case fatality rate, and the discharge rate were lower in patients who received CP containing anti-A Ab than not containing anti-A Ab CP. However, only the difference in the rate of MV support achieved statistically significance (P = 0.04) Conclusion: In our study, it was observed that the efficiency of CP without anti-A antibody was lower than that of plasma containing anti-A antibody, although it was not statistically significant. This result is thought to be due to the anti-A antibody's ability to block the ACE2 receptor. We believe that this hypothesis should be investigated in controlled studies with higher patient numbers.

Association between ABO blood groups and COVID-19 infection, severity and demise: A systematic review and meta-analysis.

BACKGROUND AND AIMS: The COVID-19 spreads rapidly around the world which has brought a global health crisis. The pathogen of COVID-19 is SARS-COV-2, and previous studies have proposed the relationship between ABO blood group and coronavirus. Here, we aim to delve into the association between ABO blood group and COVID-19 infection, severity and demise. METHODS: The relevant studies were retrieved from five databases: PubMed, MedRxiv, BioRxiv,Web of Science and CNKI. Members of cases(symptomatic cases, severe cases, died cases) and controls(asymptomatic controls, non-severe controls, alive controls) were extracted from collected studies. Odds ratios (OR) and 95% confidence intervals (CI) were calculated and interpreted from extracted data. Publication bias and sensitivity analysis were also applied to confirm our discovery. RESULTS: Overall 31,100 samples were included in the analysis. Compared to other ABO blood type, an increased odds of infecting COVID-19 among individuals with A blood group (OR: 1.249, 95%CI: 1.114-1.440, P < 0.001) and a decreased odds of infecting COVID-19 among individuals with blood group O (OR: 0.699, 95%CI: 0.635-0.770, P < 0.001) were found. Besides, individuals with blood group AB seems to link a higher risk to COVID-19 severity (OR: 2.424, 95%CI: 0.934-6.294) and demise (OR: 1.348, 95%CI: 0.507-3.583). Meantime, individuals with O blood group might had lower risk to COVID-19 severity (OR: 0.748, 95%CI: 0.556-1.007), and individuals with B blood group were likely to relate a lower risk to COVID-19 demise. CONCLUSIONS: The current meta-analysis suggest that blood type A might be more susceptible to infect COVID-19 while blood type O might be less susceptible to infect COVID-19; there were no correlation between ABO blood group and severity or demise of COVID-19. However, more investigation and research are warranted to clarify the relationship between COVID-19 and ABO blood type.