Project description:BackgroundFollowing the first reports in the literature, the association between the ABO blood group and SARS-CoV-2 infection has been investigated by a number of studies, although with varying results. The main object of this systematic review was to assess the relationship between the ABO blood group and the occurrence and severity of COVID-19.Materials and methodsA systematic literature search using appropriate MeSH terms was performed through Medline and PubMed. The outcomes considered were the prevalence of the blood group O vs non-O types in SARS-CoV-2 infected and non-infected subjects, and the severity of SARS-CoV-2 infection according to ABO group. The methodological quality of the studies included in the analysis was assessed with the Newcastle-Ottawa Scale, and the overall quality of the available evidence using the GRADE system. Benchmarks used to evaluate the effect size were odd ratios (ORs) for case control studies and risk ratios (RRs) for cohort studies.ResultsTwenty-one studies were included in the analysis. Overall, individuals with group O had a lower infection rate compared to individuals of non-O group (OR: 0.81; 95% CI: 0.75, 0.86). However, the difference in the effect size was significantly lower in cohort studies compared to case control studies. No evidence was found indicating an effect of the O type on the disease severity in the infected patients.DiscussionWe have found low/very low evidence that group O individuals are less susceptible to SARS-CoV-2 infection compared to those in the non-O group. No evidence was found indicating an effect of the O type on disease severity in SARS-CoV-2 infection.
Project description:The 2019 coronavirus disease (COVID-19) has become a global pandemic. Several studies report that ABO blood group polymorphism may be related to COVID-19 susceptibility and clinical outcomes; however, the results are controversial. We conducted a systematic review and meta-analysis to investigate whether ABO blood groups are associated with increased COVID-19 morbidity and mortality. A total of 715 articles were retrieved from seven databases. Ten articles were selected for meta-analysis after removal of duplicates and two levels of screenings. Overall, individuals with blood group A [odds ratio (OR) = 1.33, 95% confidence interval (CI) 1.14 to 1.56] and B (OR = 1.06, 95% CI 1.00 to 1.13) had a substantially higher risk of COVID-19, whereas this was not the case for blood group AB (OR = 1.07, 95% CI 0.88 to 1.30). Individuals with blood group O was not prone to develop the disease (OR = 0.71, 95% CI 0.60 to 0.84). Moreover, the risk of COVID-19 was significantly associated with the Rh-positive blood group (OR = 1.22, 95% CI 0.99 to 1.50). A meta-analysis of 5 studies suggested that blood group A was associated with a significantly increased risk of COVID-19 mortality (OR = 1.25, 95% CI 1.02 to 1.52). Mild publication bias was found in the included studies. This systematic review and meta-analysis indicated that blood groups A and B may be risk factors for COVID-19, whereas the blood group O appears to be protective. Blood group A may be related to unfavourable outcomes. Further rigorous and high-quality research evidence is needed to confirm this association.
Project description:Introduction: The SARS-CoV-2 pandemic has been affecting the health and economic, as well as social, life of the entire globe since the end of 2019. The virus causes COVID-19, with a wide range of symptoms among the infected individuals, from asymptomatic infection to mortality. This, along with a high infection rate, prompted efforts to investigate the potential mechanisms of the different clinical manifestations caused by SARS-CoV-2 among the infected populations.Hypothesis: One of the possible mechanisms that has been reported is the ABO blood system polymorphism. Indeed, one of the major proposed mechanisms is the presence of naturally occurring anti-A antibodies in individuals of groups O and B, which could be partially protective against SARS-CoV-2 virions.Objective and method: This article aimed to review the published data on the potential effect of the ABO blood group system on the susceptibility to COVID-19 and the disease progression and outcomes.Results: The reviewed data suggest that individuals of blood group A are at a higher risk of infection with SARS-CoV-2 and may develop severe COVID-19 outcomes, whereas blood group O is considered protective against the infection, to some extent. However, some of the available studies seem to have been influenced by unaccounted confounders and biases.Conclusion: Therefore, further appropriately controlled studies are warranted to fully investigate the possible association between the ABO blood groups and COVID-19 susceptibility and severity.
Project description:BACKGROUND:Malaria clinical outcomes vary by erythrocyte characteristics, including ABO blood group, but the effect of ABO blood group on asymptomatic, uncomplicated and placental Plasmodium falciparum (P. falciparum) infection remains unclear. We explored effects of ABO blood group on asymptomatic, uncomplicated and placental falciparum infection in the published literature. METHODS:A systematic review and meta-analysis was performed using the preferred reporting items for systematic reviews and meta-analyses guidelines. Articles in Pubmed, Embase, Web of Science, CINAHL and Cochrane Library published before February 04, 2017 were searched without restriction. Studies were included if they reported P. falciparum infection incidence or prevalence, stratified by ABO blood group. RESULTS:Of 1923 articles obtained from the five databases (Embase?=?728, PubMed?=?620, Web of Science?=?549, CINAHL?=?14, Cochrane Library?=?12), 42 met criteria for systematic review and 37 for meta-analysis. Most studies (n?=?30) were cross-sectional, seven were prospective cohort, and five were case-control studies. Meta-analysis showed similar odds of uncomplicated P. falciparum infection among individuals with blood group A (summary odds ratio [OR] 0.96, 15 studies), B (OR 0.89, 15 studies), AB (OR 0.85, 10 studies) and non-O (OR 0.95, 17 studies) as compared to those with blood group O. Meta-analysis of four cohort studies also showed similar risk of uncomplicated P. falciparum infection among individuals with blood group non-O and those with blood group O (summary relative risk [RR] 1.03). Meta-analysis of six studies showed similar odds of asymptomatic P. falciparum infection among individuals with blood group A (OR 1.05), B (OR 1.03), AB (OR 1.23), and non-O (OR 1.07) when compared to those with blood group O. However, odds of active placental P. falciparum infection was significantly lower in primiparous women with non-O blood groups (OR 0.46, 95% confidence interval [CI] 0.23 - 0.69, I2 0.0%, three studies), particularly in those with blood group A (OR 0.41, 95% CI 0.003 - 0.82, I2 1.4%, four studies) than those with blood group O. CONCLUSIONS:This study suggests that ABO blood group may not affect susceptibility to asymptomatic and/or uncomplicated P. falciparum infection. However, blood group O primiparous women appear to be more susceptible to active placental P. falciparum infection.
Project description:BackgroundSARS-CoV-2 infection is clinically very heterogeneous, varying from asymptomatic to severe clinical conditions with a fatal outcome. Some studies suggests that the ABO blood group could be a biological marker of susceptibility for the development of the disease.Material and methodsWe collected data from patients admitted with COVID-19 infection who had ABO blood group recorded, and analyzed the incidence by groups, compared with the global population in Navarre, as well as their main complications and evolution.ResultsGroup O was proportionally less represented in the hospitalized patients with respect to the global population, although the difference was not statistically significant. Group B had significantly higher rates of thrombotic complications and required more admissions in intensive care units.ConclusionThe study suggests a lower susceptibility to infection in group O and a higher risk of complications in group B. Studies with a larger sample size are required in order to obtain significant results.
Project description:BackgroundSARS-CoV-2 infection is clinically very heterogeneous, varying from asymptomatic to severe clinical conditions with a fatal outcome. Some studies suggests that the ABO blood group could be a biological marker of susceptibility for the development of the disease.Patients and methodsWe collected data from patients admitted with COVID-19 infection who had ABO blood group recorded, and analyzed the incidence by groups, compared with the global population in Navarre, as well as their main complications and evolution.ResultsGroup O was proportionally less represented in the hospitalized patients with respect to the global population, although the difference was not statistically significant. Group B had significantly higher rates of thrombotic complications and required more admissions in intensive care units.ConclusionThe study suggests a lower susceptibility to infection in group O and a higher risk of complications in group B. Studies with a larger sample size are required in order to obtain significant results.
Project description:BackgroundA recent study showed that the ABO gene, chr 9q34.2, which determines blood type, may affect COVID-19 disease severity, although this result has not been reproducible. A UK study of 2200 COVID-19 patients found no relationship of ABO blood type to disease severity. A Danish study identified ABO blood group as a risk factor for SARS-CoV-2 infection but not for hospitalization or death from COVID-19.AimIn the current study, we wished to analyze the relationship of ABO blood group and the ABO genetic locus to COVID-19 test positivity and mortality in subjects from the UK Biobank (UKB).MethodsABO blood type is from UKB data field 23165. Blood type was imputed for genotyped UK Biobank participants using three SNPs (rs505922, rs8176719, and rs8176746) in the ABO gene on chromosome 9q34.2. We analyzed the chromosome 9 snp rs657152 to assess the relationship of the ABO locus to COVID-19 test positivity and mortality.ResultsCOVID-19 test results (negative or positive) were not related to blood group in males (p = 0.977, two tailed Fisher exact test) or females (p = 0.548). COVID-19 outcomes (alive or died) were not related to blood group in males (p = 0.102, two tailed Fisher exact test) or females (p = 0.226). We found no significant relationship of rs657152 to COVID-19 test positivity or mortality.ConclusionWe were not able to confirm that ABO blood group influences risk of COVID-19 infection or outcome.
Project description:Objective: This meta-analysis comprehensively evaluated the association between ABO blood group and the risk of preeclampsia (PE). Design: Systematic review and meta-analysis. Data sources: PubMed, Web of Science, and ScienceDirect databases from their inception to September 23, 2020. Methods: Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were obtained through random-effects and fixed-effects models according to heterogeneity. Meta-regression analysis was applied to explore the source of heterogeneity. We conducted a subgroup analysis by the publication year, study design, state, and Newcastle-Ottawa Scale (NOS) score. In addition, we calculated the rate of each ABO blood group in PE by total pooled effects. Results: A total of 12 articles with 714,153 patients were included in our analysis. Compared with people without PE (control group), the O blood group presented a lower risk of PE (OR 0.95, 95% CI 0.93-0.97). The AB (OR 1.46, 95% CI 1.12-1.91) blood group presented a higher risk. However, the total pooled OR and 95% CI for the A (OR 1.02, 95% CI 0.90-1.16) and B (OR 1.02, 95% CI 0.98-1.05) blood groups were not significant. The funnel plot and linear regression equation showed that there was no publication bias for the O, A, or B blood groups (all P > 0.05). However, the funnel plot and linear regression equation for the AB blood group were obviously asymmetric (P < 0.05), and the publication bias persisted even after the trim-and-fill method was applied (P < 0.05). Multivariable meta-regression analysis did not find a specific source of heterogeneity. The A blood group showed an association with early-onset PE (OR 0.53, 95% CI 0.33-0.83), and the other blood groups showed no significant differences. In PE, the rates of the O, A, B, and AB blood groups decreased gradually (0.39, 0.33, 0.19, 0.07). Conclusion: These findings suggest that pregnant women with AB blood group are more likely to develop PE, and more attention should be paid to AB blood group whose blood pressure is high but not sufficient to diagnose PE. Systematic Review Registration: Prospero CRD42021227930.
Project description:ABO blood group system, a well-known genetic risk factor, has clinically been demonstrated to be linked with thrombotic vascular diseases. However, the relationship between ABO blood group and coronary artery disease (CAD) is still controversial. We here performed an updated meta-analysis of the related studies and tried to elucidate the potential role of ABO blood group as a risk factor for CAD. All detectable case-control and cohort studies comparing the risk of CAD in different ABO blood groups were collected for this analysis through searching PubMed, Embase, and the Cochrane Library. Ultimately, 17 studies covering 225,810 participants were included. The combined results showed that the risk of CAD was significantly higher in blood group A (OR = 1.14, 95% CI = 1.03 to 1.26, p = 0.01) and lower in blood group O (OR = 0.85, 95% CI = 0.78 to 0.94, p = 0.0008). Even when studies merely about myocardial infarction (MI) were removed, the risk of CAD was still significantly higher in blood group A (OR = 1.05, 95% CI = 1.00 to 1.10, p = 0.03) and lower in blood group O (OR = 0.89, 95% CI = 0.85 to 0.93, p < 0.00001). This updated systematic review and meta-analysis indicated that both blood group A and non-O were the risk factors of CAD.
Project description:We have been experiencing a global pandemic with baleful consequences for mankind, since the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was first identified in Wuhan of China, in December 2019. So far, several potential risk factors for SARS-CoV-2 infection have been identified. Among them, the role of ABO blood group polymorphisms has been studied with results that are still unclear. The aim of this study was to collect and meta-analyze available studies on the relationship between SARS-CoV-2 infection and different blood groups, as well as Rhesus state. We performed a systematic search on PubMed/MEDLINE and Scopus databases for published articles and preprints. Twenty-two studies, after the removal of duplicates, met the inclusion criteria for meta-analysis with ten of them also including information on Rhesus factor. The odds ratios (OR) and 95% confidence intervals (CI) were calculated for the extracted data. Random-effects models were used to obtain the overall pooled ORs. Publication bias and sensitivity analysis were also performed. Our results indicate that blood groups A, B and AB have a higher risk for COVID-19 infection compared to blood group O, which appears to have a protective effect: (i) A group vs O (OR = 1.29, 95% Confidence Interval: 1.15 to 1.44), (ii) B vs O (OR = 1.15, 95% CI 1.06 to 1.25), and (iii) AB vs. O (OR = 1.32, 95% CI 1.10 to 1.57). An association between Rhesus state and COVID-19 infection could not be established (Rh+ vs Rh- OR = 0.97, 95% CI 0.83 to 1.13).