Role of the AB0 blood group in COVID-19 infection and complications: A population-based study

[Genetic factors associated with long COVID]

INTRODUCTION

The variability in expression and evolution of COVID is not completely explained by clinical factors. In fact, genetic factors play an important role. Moreover, it is unknown whether the genetic factor that contribute to susceptibility and severity are also involved in the onset and evolution of long-COVID. The objective of this review is to gather information from literature to understand which genetic factors are involved in the onset of persistent COVID.

MATERIAL AND METHODS

Systematic review in PubMed and bioRxiv and medRxiv repositories based on MeSH-descriptors and MeSH-terms related to COVID and genetic factors. Using these terms 2715 articles were pooled. An initial screening performed by authors independently, selected 205 articles of interest. A final deeper screening a total of 85 articles were chosen for complete reading and summarized in this review.

RESULTS

Although ACE2 and TMPSS6 are involved in COVID susceptibility, their involvement in long-COVID has not been found. On the other hand, the severity of the disease and the onset of long-COVID has been associated with different genes involved in the inflammatory and immune response. Particularly interesting has been the association found with the FOXP4 locus.

CONCLUSIONS

Although studies on long-COVID are insufficient to fully comprehend the cause, it is clear that the current identified genetic factors do not fully explain the progression and onset of long-COVID. Other factors such as polygenic action, pleiotropic genes, the microbiota and epigenetic changes must be considered and studied.

ABO blood group-related mechanism of infection of SARS-CoV-2: an overview of systematic reviews

Among the host genetic factors playing a role in the susceptibility to infectious diseases, the ABO blood group system is of utmost importance. Following the first reports in early 2020, the association between ABO blood groups and SARS-CoV-2 infection or COVID-19 severity has been thoroughly investigated. The aim of this narrative review is to provide an overview of systematic reviews regarding the link between ABO blood groups and such risks. The possible molecular mechanisms underlying these associations will also be discussed. ABO blood group has a robust association with susceptibility to infection but not with disease severity, and studies on long COVID anre still missing.Prov.

Investigation of the Side Effects of COVID-19 Vaccines in Southern Iran: A Cross-Sectional Study

The COVID-19 disease is a newly emerging disease, and the COVID-19 vaccine is one of the necessities to prevent this disease. The present study aimed to investigate the side effects of COVID-19 vaccines in southern Iran. We used convenience sampling to conduct this cross-sectional study on 647 people living in cities under coverage in Kerman province, southern Iran. The data collection tool was a researcher-made questionnaire of vaccine symptoms and signs. The results were analyzed using ANOVA and Chi-squared tests by SPSS software (version 24). The mean age of the participants was 40.19±15.20. The results indicated that 431 people (66.6%) reported post-vaccination side effects, with 18.23% of them having severe side effects. We noticed the most severe side effects in AstraZeneca, Sinopharm, Sputnik, and Bharat. Fever, headache, and pain at the injection site were the most common side effects after vaccination in descending order, which had a statistically significant relationship with all types of vaccines (P=0.001). The side effects differed in the types of vaccines, and most of the vaccines had mild to moderate side effects. People with the B blood type showed the most severe side effects, while those with the AB showed the lowest rate of side effects. Therefore, the injection of the AstraZeneca vaccine in blood group B should be done with more caution. More attention should also be paid to blood groups B and A in the injection of COVID-19 vaccines. Moreover, health officials and the government should plan appropriate educational strategies to increase public awareness of the importance of vaccines in eradicating viral infections.

Factors related to the development of high antibody titres against SARS-CoV-2 in convalescent plasma donors from the ConPlas-19 trial

BACKGROUND AND OBJECTIVES

The efficacy of COVID-19 convalescent plasma (CP) associates with high titres of antibodies. ConPlas-19 clinical trial showed that CP reduces the risk of progression to severe COVID-19 at 28 days. Here, we aim to study ConPlas-19 donors and characteristics that associate with high anti-SARS-CoV-2 antibody levels.

MATERIALS AND METHODS

Four-hundred donors were enrolled in ConPlas-19. The presence and titres of anti-SARS-CoV-2 antibodies were evaluated by EUROIMMUN anti-SARS-CoV-2 S1 IgG ELISA.

RESULTS

A majority of 80.3% of ConPlas-19 donor candidates had positive EUROIMMUN test results (ratio ≥1.1), and of these, 51.4% had high antibody titres (ratio ≥3.5). Antibody levels decline over time, but nevertheless, out of 37 donors tested for an intended second CP donation, over 90% were still EUROIMMUN positive, and nearly 75% of those with high titres maintained high titres in the second sample. Donors with a greater probability of developing high titres of anti-SARS-CoV-2 antibodies include those older than 40 years of age (RR 2.06; 95% CI 1.24-3.42), with more than 7 days of COVID-19 symptoms (RR 1.89; 95% CI 1.05-3.43) and collected within 4 months from infection (RR 2.61; 95% CI 1.16-5.90). Male donors had a trend towards higher titres compared with women (RR 1.67; 95% CI 0.91-3.06).

CONCLUSION

SARS-CoV-2 CP candidate donors' age, duration of COVID-19 symptoms and time from infection to donation associate with the collection of CP with high antibody levels. Beyond COVID-19, these data are relevant to inform decisions to optimize the CP donor selection process in potential future outbreaks.

Association between ABO blood groups and SARS-CoV-2 infection in blood donors of Puglia region

This is an observational multicentric cross-sectional study aiming at assessing the association between ABO blood groups and SARS-CoV-2 seroprevalence among the blood donors in Puglia region. Data on ABO and Rh blood groups and demographic characteristics were obtained from Blood Bank Information System. All donors were screened for SARS-CoV-2 IgG antibodies. Comparison of seroprevalence among blood groups and the association between the recorded variables and seroprevalence were evaluated. A total of 35,709 donors from 22 centers were included, with a seroprevalence of 6.8%. The distribution of ABO phenotypes was blood type O (46.8%), A (34.0%), B (14.7%), and AB (4.5%). Among the 2416 donors reactive for SARS-CoV-2 IgG, the prevalent phenotype was blood type O (43.1%), followed by A (37.7%), B (14.2%), and AB (5%). The seroprevalence of phenotype A and AB was 7.5%, followed by B (6.5%) and O (6.2%). According to the adjusted analysis, there was an increase in seroprevalence in groups A and AB, compared to group O, and an increase in males compared to females. A possible effect modification was observed after stratifying for sex (p = 0.0515). A significantly lower prevalence of blood type O was found compared to A and AB, whereas no association was observed between Rh factor and seroprevalence. We hypothesized that the A antigen present in blood type A and AB can play a role in the binding of SARS-CoV-2 to ACE2 receptors, resulting in an increased risk of infection. Furthermore, natural anti-A/anti-B antibodies produced in group O could block viral adhesion to cells and explain a lower risk of infection.

ABO Blood Groups and Incidence of COVID-19 in the Mass Gathering Events in Borriana (Spain), March 2020: A Retrospective Cohort Study

Our objective was to estimate the incidence of COVID-19 and the ABO blood Groups in the mass-gathering events (MGEs) during the Falles Festival in Borriana (Spain) from 6-10 March 2020. We conducted a population-based retrospective cohort study and measured anti-SARS-CoV-2 antibodies and the ABO of participants. We performed laboratory COVID-19 tests and obtained the ABO in 775 subjects (72.8% of the original exposed cohort): O-group (45.2%), A-group (43.1%), B-group (8.5%) and AB-group (3.4%). Adjusted for confounding factors, including COVID-19 exposure during the MGEs, attack rates of COVID-19 for each ABO group were 55.4%, 59.6%, 60.2%, and 63.7%. The adjusted relative risks were for O-group 0.93 (95% Confidence Interval [CI] 0.83-1.04), for A-group 1.06 (95% CI 0.94-1.18), for B-group 1.04 (95%CI 0.88-1.24), and for AB-group 1.11 (95% CI 0.81-1.51) with no significant differences. Conclusions: Our results suggest no effect of ABO on COVID-19 incidence. We observed weak but not significant protection of the O-group and not a significantly greater infection risk for the remaining groups compared with the O-group. More studies are needed to resolve the controversies regarding the association between ABO and COVID-19.

COVID-19 infection and complications according to ABO blood group in the elderly: A population-based subcohort and meta-analysis

BACKGROUND AND OBJECTIVES

It is reported that ABO antibodies have a role in COVID-19 infection and severity; however, ABO antibody titres vary with advanced age. The aim was to analyse the association between ABO blood group and risk of COVID-19 infection and complications in elderly patients, and to contrast this data with findings in the overall adult population.

MATERIALS AND METHODS

A prospective cohort study of the Navarre (Spain) population aged ≥60 years and a meta-analysis of published studies including participants of ≥60 years were carried out.

RESULTS

In the Navarre elderly population, a higher risk of COVID-19 infection was identified in the A versus non-A and O group and lower risk in O versus non-O, with no significant association between hospitalization, intensive care unit admission or mortality and any of the blood groups, results that coincide with those of the overall Navarre adult population. The meta-analyses using studies that included participants of ≥60 years demonstrated a higher risk of hospitalization and mortality in A versus non-A and a lower mortality risk with B versus non-B. Similar mortality results were found in the meta-analyses of the overall adult population.

CONCLUSION

There are no relevant differences between the overall adult population and population aged ≥60 years in the risk of COVID-19 infection and severity according to ABO blood groups, suggesting that age-related changes in ABO would be of limited clinical significance.

Correlation of SARS-CoV-2 infection severity with ABO blood groups and RhD antigen: a case-control study

OBJECTIVE

The role of ABO types and RhD antigen in coronavirus disease 2019 (COVID-19) severity has been investigated in several recent studies. Thus, the objective of this study was to identify the relationship of ABO and RhD types with symptomatic COVID-19 disease and determine the groups associated with an increased risk of hospitalization.

METHODS

This observational case-control study was performed in 530 Iraqi-Kurdish patients with COVID-19. Among them, 184 were severe cases that required hospitalization, while 346 were mild to moderate cases that were treated at home. ABO and RhD antigen groups were compared between cases and 1698 control records from 1 year before the pandemic. The diagnosis of COVID-19 was based on real-time polymerase chain reaction tests and high-resolution chest computed tomography scans with the typical clinical presentation.

RESULTS

There were no significant differences in ABO and RhD antigen distributions between the COVID-19 cases and non-COVID controls. No ABO group was associated with the risk of hospitalization as a marker of the severity of infection.

CONCLUSIONS

There was no significant association between symptomatic COVID-19 disease and any ABO group or RhD antigen type. No impact of ABO groups on hospitalization was documented.

ABO blood group and link to COVID-19: A comprehensive review of the reported associations and their possible underlying mechanisms

ABO blood group is long known to be an influencing factor for the susceptibility to infectious diseases, and many studies have been describing associations between ABO blood types and COVID-19 infection and severity, with conflicting findings. This narrative review aims to summarize the literature regarding associations between the ABO blood group and COVID-19. Blood type O is mostly associated with lower rates of SARS-CoV-2 infection, while blood type A is frequently described as a risk factor. Although results regarding the risk of severe outcomes are more variable, blood type A is the most associated with COVID-19 severity and mortality, while many studies describe O blood type as a protective factor for the disease progression. Furthermore, genetic associations with both the risk of infection and disease severity have been reported for the ABO locus. Some underlying mechanisms have been hypothesized to explain the reported associations, with incipient experimental data. Three major hypotheses emerge: SARS-CoV-2 could carry ABO(H)-like structures in its envelope glycoproteins and would be asymmetrically transmitted due to a protective effect of the ABO antibodies, ABH antigens could facilitate SARS-CoV-2 interaction with the host’ cells, and the association of non-O blood types with higher risks of thromboembolic events could confer COVID-19 patients with blood type O a lower risk of severe outcomes. The hypothesized mechanisms would affect distinct aspects of the COVID-19 natural history, with distinct potential implications to the disease transmission and its management.

Relationship between ABO Blood Group Distribution and COVID-19 Infection in Patients Admitted to the ICU: A Multicenter Observational Spanish Study

Since the beginning of the COVID-19 pandemic in December 2019, a relationship between the ABO blood group type and the novel coronavirus SARS-CoV-2, the etiological agent of COVID-19, has been reported, noting that individuals with the O blood group are the least likely to be infected. Spain is one of the most badly affected countries worldwide, with high rates of patients diagnosed, hospitalized, and deceased due to COVID-19 infection. The present study aimed to analyze the possible relationship of ABO in COVID-19 patients hospitalized in different Spanish centers during the first wave of the COVID-19 pandemic, for which the ABO group was available. Physicians from the transfusion services of different Spanish hospitals, who have developed a multicenter retrospective observational study, were invited to participate voluntarily in the research and 12,115 patients with COVID-19 infection were admitted to the nine participating hospitals. The blood group was known in 1399 cases (11.5%), of which 365 (26.1%) were admitted to the ICU. Regarding the distribution of ABO blood groups, a significant increase in the non-O blood groups and reduction for the O blood group was observed in patients hospitalized due to COVID-19, compared to the reference general population. Among the patients admitted to the ICU, after multivariate analysis, adjusted for the rest of the confounding variables, patients with the O blood group presented a significantly lower risk for admission to the ICU. We conclude that an association was observed between patients with the O blood group and their lower susceptibility to SARS-CoV-2 infection, both for those admitted to the hospitalization ward and for those who required admission to the ICU.