ABO blood group influence COVID-19 infection: a meta-analysis.

INTRODUCTION: Previous studies have linked the relationship between ABO blood group and COVID-19 infection. However, existing evidence is preliminary and controversial. This meta-analysis sought to identify studies that describe COVID-19 and ABO blood group. METHODOLOGY: A literature search was conducted from PubMed, Web of Science, MedRxiv, BioRxiv and Google Scholar databases. Members of cases and controls were extracted from collected studies. Pooled Odds ratio (OR) and 95% confidence interval (95%CI) were calculated and interpreted from extracted data. Publication bias and sensitivity analysis were also applied to confirm our discovery. RESULTS: Total 13,600 patients and 3,445,047 controls were included in the study. Compared to other ABO blood group, blood group O was associated with a lower risk of COVID-19 infection (OR = 0.76, 95%CI 0.66-0.84), while blood group A and AB was associated with a higher risk (OR = 1.25, 95%CI 1.10-1.41; OR = 1.13, 95%CI 1.04-1.23, respectively). In the subgroup analysis, the relationship between blood group A, O and COVID-19 infection remained stable among Chinese, European and Eastern Mediterranean populations. In American population, blood groups B was linked with increased risk of COVID-19 infection (OR = 1.21, 95%CI 1.09-1.35). CONCLUSIONS: Our data suggested that individuals with blood types A and AB are more susceptible to COVID-19, while people with blood type O are less susceptible to infection. More research is needed to clarify the precise role of the ABO blood group in COVID-19 infection to address the global question.

The histo-blood group antigens of the host cell may determine the binding of different viruses such as SARS-CoV-2.

Viruses have caused the death of millions of people worldwide. Specifically, human viruses are grouped into 21 families, including the family of coronaviruses (CoVs). In December 2019, in Wuhan, China, a new human CoV was identified, SARS-CoV-2. The first step of the infection mechanism of the SARS-CoV-2 in the human host is adhesion, which occurs through the S glycoprotein that is found in diverse human organs. Another way through which SARS-CoV-2 could possibly attach to the host's cells is by means of the histo-blood group antigens. In this work, we have reviewed the mechanisms by which some viruses bind to the histo-blood group antigens, which could be related to the susceptibility of the individual and are dependent on the histo-blood group.

Is there an association between ABO blood types and depressive symptoms among Japanese healthcare workers during the COVID-19 pandemic?

ABO blood types could be a biological predisposition for depression. The present cross-sectional analysis was conducted amid the second wave of COVID-19 in Japan during July 2020. We wanted to investigate the association between ABO blood types and depressive symptoms among workers (352 men and 864 women, aged 21-73 years) of a medical institution in Tokyo, Japan, which took a leading role in the response to COVID-19 in the country. A Poisson regression model with a robust variance estimator was used to estimate the prevalence ratio (PR) and 95% confidence interval (CI) for depressive symptoms associated with ABO blood types. Overall, the prevalence of depressive symptoms (using two questions employed from a Two-question case-finding instrument) was 22.0%. The adjusted PRs (95% CI) for depressive symptoms, comparing the carriers of blood type O, A, and AB with those of type B, were 0.88 (0.66, 1.18), 0.81 (0.62, 1.07), and 1.07 (0.74, 1.53), respectively. There was no difference in the prevalence of depressive symptoms between non-B and B carriers. The present study did not support the association of ABO blood types with depressive symptoms.

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.

Potential benefit of vitamin D supplementation in people with respiratory illnesses, during the COVID-19 pandemic.

This review describes the evidence for the potential benefit of vitamin D supplementation in people with respiratory diseases who may have a higher susceptibility to coronavirus disease 2019 (COVID-19) infection and its consequences. Clinical evidence indicates that vitamin D may reduce the risk of both upper and lower respiratory tract infections and offers benefit particularly in people with vitamin D deficiency. Some evidence exists for a higher incidence of active tuberculosis (TB) in patients who are deficient in vitamin D. An association between low levels of 25(OH)D (the active form of vitamin D) and COVID-19 severity of illness and mortality has also been reported. In addition, low 25(OH)D levels are associated with poor outcomes in acute respiratory distress syndrome (ARDS). The cytokine storm experienced in severe COVID-19 infections results from excessive release of pro-inflammatory cytokines. Due to its immunomodulatory effects, adequate vitamin D levels may cause a decrease in the pro-inflammatory cytokines and an increase in the anti-inflammatory cytokines during COVID-19 infections. Vitamin D deficiency was found in 82.2% of hospitalized COVID-19 cases and 47.2% of population-based controls (p < 0.0001). The available evidence warrants an evaluation of vitamin D supplementation in susceptible populations with respiratory diseases, such as TB, and particularly in those who are deficient in vitamin D. This may mitigate against serious complications of COVID-19 infections or reduce the impact of ARDS in those who have been infected.

Modelling suggests ABO histo-incompatibility may substantially reduce SARS-CoV-2 transmission.

Several independent datasets suggest blood type A is over-represented and type O under-represented among COVID-19 patients. However, blood group antigens appear not to be conventional susceptibility factors in that they do not affect disease severity, and the relative risk to non-O individuals is attenuated when population prevalence is high. Here, I model a scenario in which ABO transfusion incompatibility reduces the chance of a patient transmitting the virus to an incompatible recipient - thus in Western populations type A and AB individuals are "super-recipients" while type O individuals are "super-spreaders". This results in an offset in the timing of the epidemic among individuals of different blood types, and an increased relative risk to type A/AB patients that is most pronounced during early stages of the epidemic. However, once the majority of any given population is infected, the relative risk to each blood type approaches unity. Published data on COVID-19 prevalence from regions in the early stages of the SARS-CoV-2 epidemic suggests that if this model holds true, ABO incompatibility reduces virus transmissibility by at least 60 %. Exploring the implications of this model for vaccination strategies shows that paradoxically, targeted vaccination of either high-susceptibility type A/AB or "super-spreader" type O individuals is less effective than random vaccination at blocking community spread of the virus. Instead, the key is to maintain blood type diversity among the remaining susceptible individuals. Given the good agreement between this model and observational data on disease prevalence, the underlying biochemistry urgently requires experimental investigation.

ABO Blood Types and COVID-19: Spurious, Anecdotal, or Truly Important Relationships? A Reasoned Review of Available Data.

Since the emergence of COVID-19, many publications have reported associations with ABO blood types. Despite between-study discrepancies, an overall consensus has emerged whereby blood group O appears associated with a lower risk of COVID-19, while non-O blood types appear detrimental. Two major hypotheses may explain these findings: First, natural anti-A and anti-B antibodies could be partially protective against SARS-CoV-2 virions carrying blood group antigens originating from non-O individuals. Second, O individuals are less prone to thrombosis and vascular dysfunction than non-O individuals and therefore could be at a lesser risk in case of severe lung dysfunction. Here, we review the literature on the topic in light of these hypotheses. We find that between-study variation may be explained by differences in study settings and that both mechanisms are likely at play. Moreover, as frequencies of ABO phenotypes are highly variable between populations or geographical areas, the ABO coefficient of variation, rather than the frequency of each individual phenotype is expected to determine impact of the ABO system on virus transmission. Accordingly, the ABO coefficient of variation correlates with COVID-19 prevalence. Overall, despite modest apparent risk differences between ABO subtypes, the ABO blood group system might play a major role in the COVID-19 pandemic when considered at the population level.

The Impact of ABO Blood Grouping on COVID-19 Vulnerability and Seriousness: A Retrospective Cross-Sectional Controlled Study among the Arab Community.

Background and Objectives: Studies have noted that some ABO blood types are more susceptible to COVID-19 virus infection. This study aimed to further confirm the relationship between different blood groups on the vulnerability, symptoms, cure period, and severity among COVID-19 recovered patients. Subjects and Methods: This cross-sectional study approached the participants from the Arab community via social media (mainly Facebook and WhatsApp). The data were collected through two Google Form questionnaires, one for COVID-19 recovered patients (COVID-19 group, n = 726), and the other for the healthy people (Control group, n = 707). Results: The subjects with blood group O were the least likely to be infected with the COVID-19 virus, while those with blood group A were not likely to be the most susceptible. There were significant differences among different ABO blood groups regarding the distribution of oxygen saturation percentage, myalgia, and recovery time after COVID-19 infection (p < 0.01, 0.01, and 0.05, respectively). The blood group A showed the highest percentage of patients who experienced an oxygen saturation range of 90-100%, whereas the blood group O showed the highest percentage of patients who experienced an oxygen saturation range of 70-80%. The blood group A showed the lowest percentage of patients who required artificial respiration, whereas the blood group O showed the highest percentage of patients who required artificial respiration. The blood group B showed the lowest percentage of patients who experienced myalgia and exhibited the lowest percentage of patients who needed 3 weeks or more to recover. Conclusion: The people of blood group O may be the least likely to be infected with COVID-19, however, they may be the more in need of treatment in hospital and artificial respiration compared to the other blood groups.

Association between ABO blood groups and risk of coronavirus disease 2019: A protocol for systematic review and meta-analysis.

BACKGROUND: The 2019 Coronavirus Disease (COVID-19) pandemic has threatened millions of people worldwide. Growing evidence suggests that the ABO blood type contributed to the susceptibility of COVID-19, but the results are controversial. The major objective of this systematic review and meta-analysis study is to investigate the impact of ABO blood group on COVID-19 pneumonia. METHODS: Two independent reviewers searches the databases of the China Biology Medicine disc, China National Knowledge Infrastructure, China Science and Technology Periodical Database, Wanfang Database, PubMed, Embase, and Web of Science from the date of conception to June 30, 2020. We will manually search for gray literature, such as meeting records and dissertations. Two independent reviewers will screen studies that meet the criteria, extract data, statistical data, and assess the risk of bias. The dichotomous variable will calculate the odds ratio and the corresponding 95% confidence interval. Heterogeneity between included studies will be assessed by heterogeneity χ tests and I index. The forest plots will be used to describe the pooled results. The Begg rank correlation test or Egger linear regression test will be performed to quantize the publication bias. DISCUSSION: This study will provide high-quality evidence to evaluate the contribution of the ABO blood group in COVID-19 pneumonia infection. PROSPERO REGISTRATION NUMBER: CRD42020195615.

Association Between ABO Blood Group System and COVID-19 Susceptibility in Wuhan.

Background: The ABO blood group system has been associated with multiple infectious diseases, including hepatitis B, dengue haemorrhagic fever and so on. Coronavirus disease 2019 (COVID-19) is a new respiratory infectious disease and the relationship between COVID-19 and ABO blood group system needs to be explored urgently. Methods: A hospital-based case-control study was conducted at Zhongnan Hospital of Wuhan University from 1 January 2020 to 5 March 2020. A total of 105 COVID-19 cases and 103 controls were included. The blood group frequency was tested with the chi-square statistic, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated between cases and controls. In addition, according to gender, the studied population was divided into two subgroups, and we assessed the association between cases and controls by gender. Finally, considering lymphopenia as a feature of COVID-19, the relationship between the ABO blood group and the lymphocyte count was determined in case samples. Results: The frequencies of blood types A, B, AB, and O were 42.8, 26.7, 8.57, and 21.9%, respectively, in the case group. Association analysis between the ABO blood group and COVID-19 indicated that there was a statistically significant difference for blood type A (P = 0.04, OR = 1.33, 95% CI = 1.02-1.73) but not for blood types B, AB or O (P = 0.48, OR = 0.90, 95% CI = 0.66-1.23; P = 0.61, OR = 0.88, 95% CI = 0.53-1.46; and P = 0.23, OR = 0.82, 95% CI = 0.58-1.15, respectively). An analysis stratified by gender revealed that the association was highly significant between blood type A in the female subgroup (P = 0.02, OR = 1.56, 95% CI = 1.08-2.27) but not in the male subgroup (P = 0.51, OR = 1.14, 95% CI = 0.78-1.67). The average level of lymphocyte count was the lowest with blood type A in patients, however, compared with other blood types, there was still no significant statistical difference. Conclusions: Our findings provide epidemiological evidence that females with blood type A are susceptible to COVID-19. However, these research results need to be validated in future studies.

Elevated Plasmin(ogen) as a Common Risk Factor for COVID-19 Susceptibility.

Patients with hypertension, diabetes, coronary heart disease, cerebrovascular illness, chronic obstructive pulmonary disease, and kidney dysfunction have worse clinical outcomes when infected with SARS-CoV-2, for unknown reasons. The purpose of this review is to summarize the evidence for the existence of elevated plasmin(ogen) in COVID-19 patients with these comorbid conditions. Plasmin, and other proteases, may cleave a newly inserted furin site in the S protein of SARS-CoV-2, extracellularly, which increases its infectivity and virulence. Hyperfibrinolysis associated with plasmin leads to elevated D-dimer in severe patients. The plasmin(ogen) system may prove a promising therapeutic target for combating COVID-19.