Relationship between blood group and risk of infection and death in COVID-19: a live meta-analysis

Frequency of ABO and Rh Blood Groups Among Blood Donors in the Hail Region of Saudi Arabia

OBJECTIVE

Proper blood bank inventory management and safe, efficient blood transfusion services require a thorough understanding of ABO and Rh(D) blood group distributions in specific populations. The objective of this research was to evaluate the distribution of ABO and Rh blood types among different ethnic blood donors in the Hail region of Saudi Arabia and compare the results to those of other populations.

METHODOLOGY

Data from 3,166 blood donors were analyzed retrospectively. Blood bank records provided sociodemographic information as well as blood group phenotypes. Descriptive statistics were employed. The distribution of ABO and Rh blood types was statistically examined using the chi-square test.

RESULTS

The study identified a total of 3,166 blood donors, with the majority being males (3,083 (97.4%)). The median age of the donors was 35 years, with an interquartile range of 30-41 years. Of the cohort, 1,425 (45%) consisted of young donors, defined as individuals aged 30-41 years. The O blood type accounted for 1,409 (44.5%) of all types, making it the most prevalent. The next most common blood types were B at 837 (26.4%), A at 741 (23.4%), and AB at 179 (5.7%). When combined, O positive was the most prevalent type, accounting for 1,226 (38.7%) of the total. This was followed by type B positive at 745 (23.5%), type A positive at 651 (20.6%), O negative at 183 (5.8%), AB positive at 171 (5.3%), B negative at 92 (2.9%), A negative at 90 (2.8%), and AB negative at eight (0.3%).

CONCLUSION

According to the results, out of all the ABO phenotypes, O was the most common. B, A, and AB came next. In addition, Rh(D) positivity was observed in 88.2% of the donors. These results have considerable consequences for blood transfusion strategies in the Hail region.

Relationship between blood group (ABO) and risk of COVID-19 infection in a patient cohort in Tehran, Iran

Background and purpose. Coronavirus (COVID-19) is a contagious disease causing severe acute respiratory syndrome which had a catastrophic effect on the world population and resulted in more than 2.9 million deaths worldwide. Epidemiological investigations have recently announced blood type has an association with the incidence of COVID-19 infection. Consequently, research in this regard can be effective in determining a person's susceptibility to a viral infection. Therefore, we investigated the relationship between blood types and the risk of COVID-19 in patients admitted to Khorshid laboratory, Tehran, Iran. Materials and methods. From January to March 2020, 50 nasal and throat swapb samples of patients' secretions were obtained from patients who were admitted to Khorshid laboratory. They were confirmed to have COVID-19 virus RNA and real-time polymerase chain reaction (PCR)-ABI, and their blood type was determined simultaneously. After collecting data to determine the relationship between COVID-19 infection and blood type, a confidence interval of 90 % was considered using SPSS 16. Results. The mean age of the patients was measured at 38.4±6.3 years. According to PCR results, 100 % of the subjects with COVID-19 showed blood type A. In addition, the ratio of blood type A to the percentage of reference type O was higher (P=0.009). Conclusion. There was a significant relationship between ABO blood type and susceptibility to COVID-19. As the current study suggests, those with blood type A are at a higher COVID-19 infection risk than those with blood type O.

Investigating ABO Blood Groups and Secretor Status in Relation to SARS-CoV-2 Infection and COVID-19 Severity

The ABO blood groups, Lewis antigens, and secretor systems are important components of transfusion medicine. These interconnected systems have been also shown to be associated with differing susceptibility to bacterial and viral infections, likely as the result of selection over the course of evolution and the constant tug of war between humans and infectious microbes. This comprehensive narrative review aimed to explore the literature and to present the current state of knowledge on reported associations of the ABO, Lewis, and secretor blood groups with SARS-CoV-2 infection and COVID-19 severity. Our main finding was that the A blood group may be associated with increased susceptibility to SARS-CoV-2 infection, and possibly also with increased disease severity and overall mortality. The proposed pathophysiological pathways explaining this potential association include antibody-mediated mechanisms and increased thrombotic risk amongst blood group A individuals, in addition to altered inflammatory cytokine expression profiles. Preliminary evidence does not support the association between ABO blood groups and COVID-19 vaccine response, or the risk of developing long COVID. Even though the emergency state of the pandemic is over, further research is needed especially in this area since tens of millions of people worldwide suffer from lingering COVID-19 symptoms.

Association of ABO and Rhesus blood groups with severe outcomes from non-SARS-CoV-2 respiratory infection: A prospective observational cohort study in Bristol, UK 2020-2022

Despite significant global morbidity associated with respiratory infection, there is a paucity of data examining the association between severity of non-SARS-CoV-2 respiratory infection and blood group. We analysed a prospective cohort of adults hospitalised in Bristol, UK, from 1 August 2020 to 31 July 2022, including patients with acute respiratory infection (pneumonia [n = 1934] and non-pneumonic lower respiratory tract infection [NP-LRTI] [n = 1184]), a negative SARS-CoV-2 test and known blood group status. The likelihood of cardiovascular complication, survival and hospital admission length was assessed using regression models with group O and RhD-negative status as reference groups. Group A and RhD-positive were over-represented in both pneumonia and NP-LRTI compared to a first-time donor population (p < 0.05 in all); contrastingly, group O was under-represented. ABO group did not influence cardiovascular complication risk; however, RhD-positive patients with pneumonia had a reduced odds ratio (OR) for cardiovascular complications (OR = 0.77 [95% CI = 0.59-0.98]). Compared to group O, group A individuals with NP-LRTI were more likely to be discharged within 60 days (hazard ratio [HR] = 1.17 [95% CI = 1.03-1.33]), while group B with pneumonia was less likely (HR = 0.8 [95% CI = 0.66-0.96]). This analysis provides some evidence that blood group status may influence clinical outcome following respiratory infection, with group A having increased risk of hospitalisation and RhD-positive patients having reduced cardiovascular complications.

Correlation between ABO blood type, susceptibility to SARS-CoV-2 infection and COVID-19 disease severity: A systematic review

OBJECTIVES

To verify the association between the ABO blood type and the risk of SARS-CoV-2 infection and COVID-19 disease severity.

METHODS

This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the 2020 PRISMA Checklist and flow diagram, and articles selected for review were analyzed using the Newcastle-Ottawa Quality Rating Scale. The research question was: "Would the ABO blood group influence the risk of infection and clinical course of patients infected with SARS-CoV-2?", The following databases were used: Embase, PubMed, Virtual Health Library (VHL), Web of Science, ScienceDirect and Scopus. The protocol for this review was registered in the Prospective Register of Systematic Reviews (PROSPERO), number CRD42021245945.

RESULTS

We found 798 articles across PubMed, Embase, Scopus, Web of Science, Science Direct and Virtual Health Library and 54 articles were included in the final analysis. Among 30 studies evaluating the risk of COVID-19 infection, 21 found significant correlations with ABO blood groups, 14 of them revealing an increased risk in blood group A and 15 studies showing a decreased risk in blood group O. Most studies found no significant correlation with disease severity or mortality.

CONCLUSION

The qualitative assessment of available information suggests that blood group A may be a risk factor for COVID-19 infection and that blood group O may have a protective effect. We were unable to determine a clear association between the ABO blood group and mortality. These conclusions are based on highly heterogenous evidence.

Association Between Blood Groups and COVID-19 CT Severity: A Retrospective Analysis From a Tertiary Care Center

INTRODUCTION

The COVID-19 infection can have varied severity; presenting symptoms include fever, coughing, headaches, sore throats, exhaustion, muscle aches, loss of taste or smell, rhinorrhea, stomach pain, diarrhea, and vomiting. In various parts of the world, including India, researchers have looked into the relationship between blood type and the severity of SARS-CoV-2 infection. The aim of the study is to investigate the relationship between COVID-19 infection severity and blood group.

METHODOLOGY

A total of 1,222 COVID-19 patients with real-time reverse transcription-polymerase chain reaction (RT-PCR) confirmation of being COVID-positive were included in the study. Mortality rates, demographic information, comorbid illnesses, epidemiological information, laboratory test results, and comorbid disorders were all retrieved. Each participant's RH type and Groups A, B, O, and AB were determined. IBM SPSS software version 26 (IBM Corp., Armonk, NY) was used for the statistical analysis. For a normal distribution, quantitative variables were shown as mean standard deviation (SD), and for a non-normal distribution, median (interquartile range (IQR)). Frequency and percentages were used to present qualitative characteristics.

RESULTS

Out of the 1,222 patients included in the study, 369 were normal, 406 were mild, 317 were moderate, and 130 were severe based on COVID-19 CT severity scoring. Among the blood groups, O positive (+) was the most common with 503 (41.2%) study participants, and AB negative (-) was the least common with seven (0.6%) participants.

DISCUSSION

In our study, comparing various blood groups, blood group O individuals have the highest risk of developing severe COVID-19 illness, and blood group AB individuals have a reduced risk. In terms of Rh status, patients who are Rh-positive are at increased risk of developing severe COVID-19 infection when compared with Rh- individuals. In the Indian population, blood group O is the commonest, and blood group AB is the least prevalent. Most of the individuals were Rh+, and the rest were Rh-. This is attributed to the increased infection rate in individuals with O+ blood type seen in our study when compared with other studies.

CONCLUSION

The findings indicated that individuals with blood groups A, B, and AB may be at a higher risk of severe COVID-19 infection, while blood group O might provide some protective effect. These results align with previous studies worldwide, suggesting that blood groups could influence the susceptibility to and severity of viral infections. The study emphasizes the need for further research with larger sample sizes and diverse populations to validate these findings and explore the underlying mechanisms.

Link between human ABO blood groups with diseases influencing blood donors and recipients frequency at RBTC, Delhi, India

Blood groups had associations with many diseases that affect blood transfusion services by increasing or decreasing the blood demand of particular blood group. The present study was designed to compare the frequency of ABO and Rh blood groups among blood donors and blood component recipients. The ABO and Rh(D) blood groups of donors and recipients were determined using Gel card method. The frequency of blood donors and blood component recipients from January 1, 2020, to December 31, 2023, at regional blood transfusion centre of Delhi, were compared using χ² test. The ABO blood group frequencies of blood donors (n=23025) were: A(23.1%), B(37.53%), AB(10.09%), and O(29.29%). The blood issue (n=20255) was significantly (p=0.0000) higher in A(24.96%), B(39.92%), and lower in AB(9.76%) and O(25.37%). The RDP issue (n=7239) was significantly (p=0.0000) higher in A(24.71%), B(39.34%), and AB(11.53%) and lower in O(24.41%). The FFP issue (n=4164) was significantly (p=0.00024) higher in AB (12.3%) and lower in A (22.05%), B(37.32%), and O(28.14%). The difference between the blood donor frequencies of Rh(D)+Ve(95.19%) and Rh(D)-Ve(4.81%) and the blood issued by Rh(D)+Ve(95.06%) and Rh(D)-Ve(4.94%) was statistically not significant(P=0.52).Blood issues were higher in blood group A and B than in O, platelet issues were higher in A, B and AB than in O, and FFP issues were higher in the AB. Non-O blood groups may have a higher frequency of blood transfusions, while O blood groups may have a protective influence against diseases due to their innate immune response.

Phenotype, allele and genotype frequency distribution of ABO and Rh(D) blood group among blood donors attending regional blood transfusion centre in Delhi, India

The ABO and Rh blood group phenotypes, alleles, and genotype frequencies have many biological and medical implications. The frequency differs broadly according to races, geographical borders and ethnicity, even within the same region. This study was designed to determine the frequency of ABO and Rh blood groups among blood donors attending the regional blood transfusion centre in Delhi. The gel card method was used to determine the ABO and Rh(D) blood groups of donors who donated blood between January 1, 2020, and June 30, 2022. The assumption of Hardy-Weinberg equilibrium was used to determine allele and genotype frequencies of blood donors. A total of 16,925 blood units were donated during the study period. Donors phenotype frequencies of ABO were as follows: 'A' (23.88%), 'B' (37.38%), 'AB' (9.97%) and 'O '(29.27%). Rh(D)+Ve (D) were (94.9%) and Rh(D)-Ve (d) were (5.01%), which follow an order of B > O > A > AB and Rh-D > d for Rh. Donors ABO and Rh (D) allele frequencies were IA-0.183, IB-0.277, IO-0.541 and ID-0.776, Id-0.224 respectively. Allele frequencies follow an order of IO > IB > IA and Rh- ID > Id. Donors ABO genotype frequencies were AA-0.0333, AO-0.198, BB-0.0768, BO-0.30, AB-0.101, OO-0.293 and Rh(D) genotype frequencies were DD-0.602, Dd-0.347, dd-0.0501. Genotype frequencies follow an order of BO > OO > AO > AB > BB > AA and DD > Dd > dd. Among our donors, which were mostly from northern India, the ABO and Rh(D) blood groups have the highest proportion of ABO-B and Rh(D)+Ve and the lowest proportion of ABO-AB and Rh(D)-Ve, with a stable order of B > O > A > AB and D > d for phenotype, IO > IB > IA and ID > Id for allele and BO > OO > AO > AB > BB > AA and DD > Dd > dd for genotype.

Age, comorbidities, c-reactive protein and procalcitonin as predictors of severity in confirmed COVID-19 patients in the Philippines

Background

The Coronavirus Disease 2019 (COVID-19) pandemic has been affecting people globally, and the Philippines is one of the countries greatly struck by the virus. The continued rise of new positive cases has drawn attention to the urgent need for healthcare management to cope with this challenge. Severity prediction could help improve medical decision-making and optimise the patient's treatment plan with a good clinical outcome. This study aimed to identify the determinants of COVID-19 disease severity.

Methods

Demographic characteristics and laboratory findings were collected from electronic medical records and paper forms of all confirmed COVID-19 cases reported by the University of Perpetual Help DALTA Medical Center between the September 1, 2020 and the October 31, 2021. We performed statistical analyses and interpretation of data to compare severe and non-severe groups.

Results

5,396 confirmed cases were examined. Most of the severe cases were elderly, male, had blood type A, and with comorbidities. Cycle threshold (Ct) values were lower in the severe group. Most patients had higher-than-normal levels of all blood parameters except platelet, white blood cell (WBC), neutrophil, and lymphocyte counts. Age, sex, ABO blood groups, comorbidities, open reading frame 1 ab (ORF1ab) and nucleocapsid (N) gene Ct values, ferritin, C-reactive protein (CRP), procalcitonin (PCT), D-dimer, white blood cell (WBC) count, neutrophil count, and lymphocyte count were significantly associated with disease severity. In multivariate analysis, age groups >60 and 30-59 years, presence of comorbidities, CRP level >5 ng/mL, and PCT >0.05 ng/mL were identified as disease severity predictors.

Conclusions

Based on our results, age, comorbidities, CRP, and PCT level may be utilised as primary assessment factors for possible hospital admission and close monitoring upon testing. Early detection of these risk factors may provide strategic interventions that help reduce mortality, hospital admissions, and more expensive and extensive treatments.

Gender and sex bias in COVID-19 epidemiological data through the lens of causality

The COVID-19 pandemic has spurred a large amount of experimental and observational studies reporting clear correlation between the risk of developing severe COVID-19 (or dying from it) and whether the individual is male or female. This paper is an attempt to explain the supposed male vulnerability to COVID-19 using a causal approach. We proceed by identifying a set of confounding and mediating factors, based on the review of epidemiological literature and analysis of sex-dis-aggregated data. Those factors are then taken into consideration to produce explainable and fair prediction and decision models from observational data. The paper outlines how non-causal models can motivate discriminatory policies such as biased allocation of the limited resources in intensive care units (ICUs). The objective is to anticipate and avoid disparate impact and discrimination, by considering causal knowledge and causal-based techniques to compliment the collection and analysis of observational big-data. The hope is to contribute to more careful use of health related information access systems for developing fair and robust predictive models.

ABO Blood Group in Relation to COVID-19 Susceptibility and Clinical Outcomes: A Retrospective Observational Study in the United Arab Emirates

(1) Background: The association between ABO blood groups and COVID-19 outcomes was investigated in several studies. The results were controversial. This study aimed to explore the association between ABO blood groups and COVID-19 outcomes. (2) Methods: This retrospective study included 303 COVID-19 patients treated at the NMC Royal Hospital in the United Arab Emirates between 8 April 2020 and 30 June 2020. (3) Results: The mean age of patients included in the study was 39.3 ± 10.7 years, and 72.9% of patients were males. The prevalence of blood groups O, A, B, and AB was 40.3%, 27.7%, 25.1%, and 6.9%, respectively. The correlation between ABO blood groups and COVID-19 outcomes was insignificant except in the AB group, with significantly higher odds of disease severity. Increased age, higher body mass index (BMI), and being of male gender increased the risk for pneumonia among all blood groups. Both increased age and higher BMI increased the risk of mortality, and increased age increased the risk of disease severity. Troponin and platelet counts were significantly different in the A group compared to the non-A groups. Time to viral clearance was not different among blood groups. However, adjustment for Rh groups resulted in a significantly shorter time in the B group. (4) Conclusions: There was no significant association between ABO blood groups and COVID-19 outcomes, with the exception of group AB.

Systematic review and meta-analysis of the effect of ABO blood group on the risk of SARS-CoV-2 infection

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).

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

Since the beginning of the COVID-19 pandemic, the ABO blood group has been described as a possible biological marker of susceptibility for the disease. This study evaluates the role of ABO group on the risk of SARS-CoV-2 infection and related complications in a population-based cohort including 87,090 subjects from the Navarre population (Northern Spain) with no history of SARS-CoV-2 infection and with known ABO blood group, after one year of the pandemic (May 2020 - May 2021). The risk of infection, hospitalization, Intensive Care Unit (ICU) admission and death was analyzed using multivariate logistic regression, adjusting for possible confounding variables. A lower risk of infection was observed in group 0 vs non-0 groups [OR 0.94 (95 %CI 0.90-0.99)], a higher risk of infection in group A vs non-A groups [OR 1.09 (95 %CI 1.04-1.15)] and a higher risk of infection in group A vs group 0 [OR 1.08 (95CI 1.03-1.14)] (when the 4 groups are analyzed separately). No association was observed between blood groups and hospitalization, ICU admission, or death in SARS-CoV-2 infected subjects. Regarding the risk of SARS-CoV-2 infection, we observed a protective role of group O and a greater risk in the A group.

The Role of ABO Blood Type in Patients with SARS-CoV-2 Infection: A Systematic Review

The SARS-CoV-2 infection has caused over 422 million contagions and 5.8 million deaths resulting in a global health crisis. Several studies have investigated the risk factors predisposing to the infection and reported that the host susceptibility can be linked to the ABO blood group, but the current evidence is controversial. We systematically searched for articles in EMBASE, PubMed, and Cochrane library published up to 7 May 2021 to explore the association of the ABO blood group with the susceptibility to SARS-CoV-2 infection. All studies in people undergoing SARS-CoV-2 test controls were included. Odds ratios were obtained in each study and then synthesised by using meta-analysis. Overall, 22 articles were selected and more than 1,200,000 individuals of whom 74,563 resulted positive to SARS-CoV-2 and 1,166,717 resulted negative, were included in the meta-analysis. Overall, 487,985 subjects had blood group A, 151,879 had group B, 52,621 had group AB, and 548,795 had group O. Group O was slightly less associated with infection, as compared to the other three blood groups (OR = 0.91, 95% CI = 0.85-0.99, p = 0.02). Conversely, group A was slightly more associated with infection, as compared to the other three groups (OR = 1.06, 95% CI = 1.00-1.13, p = 0.04). This meta-analysis shows associations between blood groups and SARS-CoV-2 infection and supports the hypothesis that blood type O may have a slightly lower risk of infection, whereas blood type A may have a slightly higher risk of infection.

Association of ABO blood group with respiratory disease hospitalization and severe outcomes: a retrospective cohort study in blood donors

OBJECTIVES

Environmental, socioeconomic, and genetic factors all are associated with respiratory diseases. We aimed to investigate the association between the ABO blood group and the susceptibility to respiratory diseases.

METHODS

We constructed a retrospective cohort study of blood donors in Shaanxi, China between January 1, 2012, and December 31, 2018, to investigate the impacts of the ABO blood group on the risk of hospitalization due to respiratory diseases.

RESULTS

Of 1,686,263 enrolled participants (680,788 females), 26,597 were admitted to the hospital for respiratory diseases. Compared with blood group O, blood groups A, B, and AB all demonstrated a higher risk for diseases of the upper respiratory tract (International Classification of Diseases, Tenth Revision: J30-J39) (ARR (Adjusted relative risk) 1.139, 95% confidence interval [1.106-1.225]; 1.095 [1.019-1.177]; 1.178 [1.067-1.30], respectively). Conversely, blood group A was found to have a lower risk (0.86 [0.747-0.991]) for influenza (J09-J11) and blood group B had a lower risk for pneumonia (J12-J18) (0.911 [0.851-0.976]) than blood group O. The duration of hospitalization was significantly different across the blood groups in J09-J11 and J30-J39 (P <0.05).

CONCLUSION

The blood group appears to be a prognostic factor in differentiating the occurrence of specific respiratory diseases and duration.

Association of ABO blood group with susceptibility to SARS-CoV-2 infection in Rupandehi district of Nepal

Objectives:

Recent studies after the outbreak of coronavirus disease 2019 have shown an association of the ABO blood group to the susceptibility of severe acute respiratory syndrome coronavirus 2 infection. Anti-A and anti-B antibodies, carbohydrate clustering, interleukin-6 levels and host transmembrane protease serine subtype 2 were suggested to cause the variable susceptibility of severe acute respiratory syndrome coronavirus 2 infection to the ABO blood groups. This study aims to find the association of the ABO blood group with severe acute respiratory syndrome coronavirus 2 infection susceptibility in Nepal.

Methods:

Population-based matched case–control study was conducted from October 2021 to February 2022 in Rupandehi district of Nepal. A total of 1091 reverse transcription-polymerase chain reaction confirmed coronavirus disease 2019 cases and 2182 controls were included in the study by convenient sampling method.

Results:

A statistically significant association of severe acute respiratory syndrome coronavirus 2 infection was observed for the blood group AB between cases and controls (11.5% vs 8.5%; odds ratio = 1.4, 95% confidence interval = 1.10–1.78). However, there was no association of severe acute respiratory syndrome coronavirus 2 infection for blood group A (26.7% vs 28.23%; odds ratio = 0.93, 95% confidence interval = 0.79–1.09), B (26.9% vs 29.84%; odds ratio = 0.86, 95% confidence interval = 0.73–1.02) and O (34.9% vs 33.41%; odds ratio = 1.07, 95% confidence interval = 0.92–1.25).

Conclusion:

This study reported slightly more susceptibility to severe acute respiratory syndrome coronavirus 2 infection among individuals with blood group AB.

Clinical Manifestations, Imaging Procedures and Laboratory Parameters among Hospitalized Patients with COVID-19 in Ilam Province, Western Iran

Background

COVID-19 is the last global threat which WHO confirmed it as a pandemic on March 11, 2020. In the Middle East, Iran was the first country where the SARS-Cov-2 was detected. The epidemiological and economic challenges of Iran make this country a particularly relevant subject of study. In the current study, we aimed to evaluate the clinical, radiological and laboratory findings in hospitalized COVID-19 confirmed cases in Ilam province, western of Iran.

Methods

Overall, 2204 hospitalized RT-PCR confirmed patients with COVID-19 were considered in this study. Electronic medical records, including clinical symptoms, radiological images, laboratory findings, and the comorbidities of patients with COVID-19 were collected and analyzed. In addition, the medication regimens used in these patients were evaluated. The patients were classified in discharged and died groups according to their outcomes. Then, clinical, radiological and laboratory findings as well as treatment regimens and underlying diseases were compared in these two groups.

Results

Among the patients, 1209 (54.85%) were male and 995 (45.14%) were female. Pneumonia, dyspnea and cough, were the most common clinical data in both discharged and died groups. Among the comorbidities, COPD, and cancer were significantly more common in the dead patients than in the living. The results of laboratory tests showed that blood creatinine, BUN, ESR, Na+, WBC, and neutrophil count have increased in deceased group compared to the survivors. However, the lymphocyte count decreased in deceased patients. The evaluation of radiographs demonstrated that there were significant correlations between bilateral pneumonia, ground glass opacity, bilateral patchy shadowing, and pleural effusion with death.

Conclusion

The current investigation indicated the special profile of COVID-19 in west of Iran. Discharged and dead patients with COVID-19 had distinct clinical, radiological and laboratory features, which were separated by principal component analysis. Identifying these characteristics of the disease would translate into the implementation of practical measures to improve results.

SARS-CoV-2 Infection in Iranian People Living with Human Immunodeficiency Virus-1 Infection

Background: A novel Coronavirus first emerging in Wuhan, China, was named severe acute respiratory syndrome Coronavirus 2 (SARS‐CoV‐2). The disease caused by SARS‐CoV‐2 is known as Coronavirus disease 2019 (COVID‐19). HIV-1 infected individuals may be at risk of COVID-19. Objectives: This cross-sectional study evaluated the SARS-CoV-2 infection rate and COVID-19 prevalence among Iranian HIV-1-infected people. Methods: The study was conducted on 155 HIV-1-infected patients from June 2020 to October 2020. COVID-19 Ab (IgG) was detected using an enzyme immunoassay in serum specimens. Furthermore, nasopharyngeal and oropharyngeal specimens were collected. Then, the genomic RNA of SARS‐CoV‐2 was detected using a real-time polymerase chain reaction (RT-PCR). Clinical symptoms of the studied participants with and without COVID-19 were examined. Results: Of 155 HIV-1-infected individuals, 12 (7.7%) had positive real-time PCR results for SARS-CoV-2. Out of 12 (7.7%) patients with COVID‐19, four (33.3%) were males. Anti-COVID Ab (IgG) was detected in 10 (6.5%) participants, of whom eight (80.0%) were males. The most common COVID-19 clinical symptoms, including dry cough, fever, runny nose, anosmia, and hypogeusia, were observed in seven (58.3%), five (41.7%), five (41.7%), five (41.7%), and five (41.7%) patients with COVID-19, respectively. Conclusions: A recent study has shown that the risk of SARS‐CoV‐2 infection in HIV-infected individuals is similar to that in the general population.

Allelic Variants Within the ABO Blood Group Phenotype Confer Protection Against Critical COVID-19 Hospital Presentation

Introduction: Coronavirus disease 2019 (COVID-19) disease severity differs widely due to numerous factors including ABO gene-derived susceptibility or resistance. The objective of this study was to investigate the association of the ABO blood group and genetic variations of the ABO gene with COVID-19 severity in a heterogeneous hospital population sample from the United Arab Emirates, with the use of an epidemiological and candidate gene approach from a genome-wide association study (GWAS). Methods: In this cross-sectional study, a total of 646 participants who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were recruited from multiple hospitals and population-based (quarantine camps) recruitment sites from March 2020 to February 2021. The participants were divided into two groups based on the severity of COVID-19: noncritical (n = 453) and critical [intensive care unit (ICU) patients] (n = 193), as per the COVID-19 Reporting and Data System (CO-RADS) classification. The multivariate logistic regression analysis demonstrated the association of ABO blood type as well as circulating anti-A antibodies and anti-B antibodies as well as A and B antigens, in association with critical COVID-19 hospital presentation. A candidate gene analysis approach was conducted from a GWAS where we examined 240 single nucleotide polymorphisms (SNPs) (position in chr9: 136125788-136150617) in the ABO gene, in association with critical COVID-19 hospital presentation. Results: Patients with blood group O [odds ratio (OR): 0.51 (0.33, 0.79); p = 0.003] were less likely to develop critical COVID-19 symptoms. Eight alleles have been identified to be associated with a protective effect of blood group O in ABO 3'untranslated region (UTR): rs199969472 (p = 0.0052), rs34266669 (p = 0.0052), rs76700116 (p = 0.0052), rs7849280 (p = 0.0052), rs34039247 (p = 0.0104), rs10901251 (p = 0.0165), rs9411475 (p = 0.0377), and rs13291798 (p = 0.0377). Conclusion: Our findings suggest that there are novel allelic variants that link genetic variants of the ABO gene and ABO blood groups contributing to the reduced risk of critical COVID-19 disease. This study is the first study to combine genetic and serological evidence of the involvement of the ABO blood groups and the ABO gene allelic associations with COVID-19 severity within the Middle Eastern population.

The relationship between blood groups and risk of infection with SARS-CoV-2 or development of severe outcomes: A review

The outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered a global catastrophe that has overwhelmed health care systems. Since initiation of the pandemic, identification of characteristics that might influence risk of infection and poor disease outcomes have been of paramount interest. Blood group phenotypes are genetically inherited characteristics whose association with certain infectious diseases have long been debated. The aim of this review is to identify whether a certain type of blood group may influence an individual's susceptibility to SARS-CoV-2 infection and developing severe outcomes. Our review shows that blood group O protects individuals against SARS-CoV-2, whereas blood group A predisposes them to being infected. Although the association between blood groups and outcomes of COVID-19 is not consistent, it is speculated that non-O blood group carriers with COVID-19 are at higher risk of developing severe outcomes in comparison to O blood group. The interaction between blood groups and SARS-CoV-2 infection is hypothesized to be as result of natural antibodies against blood group antigens that may act as a part of innate immune response to neutralize viral particles. Alternatively, blood group antigens could serve as additional receptors for the virus and individuals who are capable of expressing these antigens on epithelial cells, which are known as secretors, would then have a high propensity to be affected by SARS-CoV-2.

Effects of selected inherited factors on susceptibility to SARS-CoV-2 infection and COVID-19 progression

Genetic predispositions may influence geographical and interethnic differences in COVID-19 prevalence and mortality in affected populations. Of the many genes implicated in COVID-19 progression, a substantial number have no direct functional link on virus transfer/viability or on the host immune system. To address this knowledge deficit, a large number of in silico studies have recently been published. However, the results of these studies often contradict the findings of studies involving real patients. For example, the ACE2 has been shown to play an important role in regulating coronavirus entry into cells, but none of its variations have been directly associated with COVID-19 susceptibility or severity. Consistently was reported that increased risk of COVID-19 is associated with blood group A and with the APOE4 allele. Among other genes with potential impacts are the genes for CCR5, IL-10, CD14, TMPRSS2 and angiotensin-converting enzyme. Variants within the protein-coding genes OAS1 and LZTFL1 (transferred to the human genome from Neanderthals) are understood to be among the strongest predictors of disease severity. The intensive research efforts have helped to identify the genes and polymorphisms that contribute to SARS-CoV-2 infection and COVID-19 severity.

The Usefulness of Rare Blood Group Systems in the Risk Determination for Severe COVID-19

The newly identified human coronavirus was named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), based on a detailed analysis of clinical manifestation. It was reported that blood type O individuals were less likely to become infected by SARS-CoV, while blood type A individuals have an increased risk of severe illness. The Forssman antigen, or Forssman glycolipid synthase (FS), was first described in 1911 by John Frederick Forssman. Blood type A/B glycosyltransferases (AT/BTs) and Forssman glycolipid synthase (FS) are encoded by the evolutionarily related ABO (A/B alleles) and GBGT1 genes. In this article, based on published studies about the pathogenesis of the COVID-19, we hypothesize the possible relationship between the COVID-19 infection and rare blood type systems, such as the Forssman antigen system.

Clinical and epidemiological characteristics of COVID-19 mortality in Saudi Arabia

OBJECTIVES

To analyze the clinical and epidemiological characteristics for 224 of in-hospital coronavirus disease 2019 (COVID-19) mortality cases. This study's clinical implications provide insight into the significant death indicators among COVID-19 patients and the outbreak burden on the healthcare system in the Kingdom of Saudi Arabia (KSA).

METHODS

A multi-center retrospective cross-sectional study conducted among all COVID-19 mortality cases admitted to 15 Armed Forces hospitals across KSA, from March to July 2020. Demographic data, clinical presentations, laboratory investigations, and complications of COVID-19 mortality cases were collected and analyzed.

RESULTS

The mean age was 69.66±14.68 years, and 142 (63.4%) of the cases were male. Overall, 30% of the COVID-19 mortalities occurred in the first 24 hours of hospital admission, while 50% occurred on day 10. The most prevalent comorbidities were diabetes mellitus (DM, 73.7%), followed by hypertension (HTN, 69.6%). Logistic regression for risk factors in all mortality cases revealed that direct mortality cases from COVID-19 were more likely to develop acute respiratory distress syndrome (odds ratio [OR]: 1.75, confidence intervel [CI: 0.89-3.43]; p=0.102) and acute kidney injury (OR: 1.01, CI: [0.54-1.90]; p=0.960).

CONCLUSION

Aging, male gender and the high prevalence of the underlying diseases such as, DM and HTN were a significant death indicators among COVID-19 mortality cases in KSA. Increases in serum ferritin, procalcitonin, C-reactive protein (CRP), and D-dimer levels can be used as indicators of disease progression.

Recent updates on the possible reasons for the low incidence and morbidity of COVID-19 cases in Africa

BACKGROUND

The COVID-19 respiratory illness caused by the SARS-CoV-2 has been a major cause of morbidity and mortality worldwide since the first reported case in Wuhan, China. A year has passed since pandemic began, and the reasons for different COVID-19 burden variation across continents keep puzzling the general public.

MAIN BODY OF THE ABSTRACT

Since the COVID-19 pandemic started, published research articles have addressed the epidemiological risk factors, host factors, susceptibility and immunity. To ascertain possible reasons for the different rates of COVID-19 infections between Africa and other continents, we summarized the up-to-date scientific literature to identify possible arguments in this regard. Available literature suggests that demographic, epidemiological, sociological, genetic and immunological factors contribute in the COVID-19 severity and the susceptibly to SARS-CoV-2.

SHORT CONCLUSION

This review summarizes existing data and discusses reasons for differential COVID-19 burden across continents. The arguments mentioned herein will be helpful to guide future experimental studies to test different hypotheses.

Nanotechnology Integration for SARS-CoV-2 Diagnosis and Treatment: An Approach to Preventing Pandemic

The SARS-CoV-2 outbreak is the COVID-19 disease, which has caused massive health devastation, prompting the World Health Organization to declare a worldwide health emergency. The corona virus infected millions of people worldwide, and many died as a result of a lack of particular medications. The current emergency necessitates extensive therapy in order to stop the spread of the coronavirus. There are various vaccinations available, but no validated COVID-19 treatments. Since its outbreak, many therapeutics have been tested, including the use of repurposed medications, nucleoside inhibitors, protease inhibitors, broad spectrum antivirals, convalescence plasma therapies, immune-modulators, and monoclonal antibodies. However, these approaches have not yielded any outcomes and are mostly used to alleviate symptoms associated with potentially fatal adverse drug reactions. Nanoparticles, on the other hand, may prove to be an effective treatment for COVID-19. They can be designed to boost the efficacy of currently available antiviral medications or to trigger a rapid immune response against COVID-19. In the last decade, there has been significant progress in nanotechnology. This review focuses on the virus's basic structure, pathogenesis, and current treatment options for COVID-19. This study addresses nanotechnology and its applications in diagnosis, prevention, treatment, and targeted vaccine delivery, laying the groundwork for a successful pandemic fight.

Role of ABO blood system in COVID-19: Findings from a southern Italian study

BACKGROUND

COVID-19 is a worldwide infection caused by SARS-CoV-2 and infects humans by binding to the ACE2 receptor. Blood group ABO glycoproteins can influence the binding of the virus to ACE2. The role of ABO blood system in the susceptibility to infection as well as in the clinical outcome of infected patients is still controversial and needs to be clarified.

METHODS

We conducted a retrospective study of 167 patients positive for SARS-CoV-2 who underwent nasopharyngeal swab, and of a control group represented by 891 subjects negative for SARS-CoV-2, to assess the association between ABO and Rh blood system and occurrence of SARS-CoV-2 infection, clinical presentation, and outcome of disease.

RESULTS

In the cohort of patients positive for SARS-CoV-2, no statistically significant difference in the distribution of ABO blood types compared with controls was observed. Patients with blood type A had a higher risk of developing symptomatic disease (p = 0.002; odds ratio [OR = 3.592]; 95% confidence interval [CI] = 1.576-8.187) compared to patients with blood types B, AB, and O. Patients with blood types B (p = 0.021; OR = 0.293; 95%CI = 0.099-0.869) and O (p = 0.018; OR = 0.417; 95%CI = 0.199-0.871) showed a lower risk in comparison to the other groups. The clinical progression to mild/moderate and severe/critical disease and the mortality showed no association. Moreover, no relationship with Rh blood type was found.

CONCLUSIONS

Our findings support a role of ABO blood type in the development of symptomatic disease with a higher risk in subjects with blood type A and a protective effect of blood types B and O. Blood types do not seem, however, to play a role in susceptibility, progression to severe disease, and death.

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.

Systematic review and meta-analysis of the susceptibility of ABO blood group to COVID-19 infection

Background

Numerous studies investigate the association between the ABO blood groups and the occurrence of COVID-19 infection; discordant findings were reported. Therefore, the purpose of this meta-analysis was to evaluate the existing evidence on the susceptibility of the ABO blood group to COVID-19 infection.

Methods

Systematically searched published articles in PubMed, Google Scholar, Scopus, and EMBASE between 1 st January 2020 and 21 st March 2021. After quality control and the exclusion of irrelevant studies, 16 studies were included in the final analysis.

Results

Although the random-effect meta-analysis revealed a large heterogeneity among studies, I 2 = 99.197 %. The pooled event rates and (95 % CIs) for A, O, B, and AB blood group were 0.459 (95 %CI: 0.358–0.441), 0.342 (95 %CI: 0.298–0.374), 0.180 (95 %CI: 0.150–0.214), and 0.076 (95 %CI: 0.055–0.127), respectively. These results indicated that the COVID-19 infection rate was higher in persons with blood group A > O > B > AB. Overall, the ABO blood group's vulnerability to COVID-19 infection was statistically significant (pooled p -value<0.001).

Conclusion

This meta-analysis offers a further indication of blood group A individuals' vulnerability to COVID-19 infection, and blood type AB are linked to a lower risk of COVID-19 infection.

ABO blood group and COVID-19: an updated systematic literature review and meta-analysis

BACKGROUND

Following 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 METHODS

A 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.

RESULTS

Twenty-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.

DISCUSSION

We 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.

ABO in Correlation to the Requirement of Mechanical Ventilation and Mortality in Critically Ill Patients With COVID-19

Background

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that was first discovered in December 2019 and turned to be pandemic in early March 2020. We aimed to describe the dominant ABO group and outcomes of critically ill patients (respiratory failure requiring mechanical ventilation and mortality) in a Saudi Arabian setting.

Methods

We conducted an observational, analytic cross-sectional, retrospective study in a tertiary care hospital. Around 90 candidates tested positive for COVID-19 were enrolled in this study during admission to critical care unit between May 2020 and September 2020. Blood group was detected in all patients included in the study during admission to critical care unit.

Results

In this study, data of 90 patients with COVID-19 admitted to critical care unit were collected. Some prevalent medical conditions were collected, in which hypertension (64.2%) and diabetes mellitus (58.9%) were the most reported comorbidities among patients and there was no significant difference between groups. Most of the sample had blood group of O (45.6%), while the least group was AB (5.6%). Patients with blood group of A/AB showed the highest mortality vs. group O/B (32% vs. 18.5%) with significant P value of 0.001. Patients of groups A/AB had higher risk for intubation than O/B groups (52.0% and 49.2%, respectively; confidence interval of 0.44 - 2.8 with insignificant P value of 0.055). Length of stay in critical care unit was significantly higher in group A/AB with a mean course of 18.20 days in comparison to group O/B with a mean course of 12.63 days (P = 0.033).

Conclusion

Our data indicate that critically ill patients with COVID-19 with blood group A/AB are at increased risk of mortality and length of stay in critical care unit, with insignificant requirement of mechanical ventilation when compared with patients with blood group O/B. Future larger studies are needed to validate and understand the underlying mechanisms.

A Study on Otorhinolaryngological Presentations in Covid 19 Patients in a Tertiary Health Care Center

Corona virus also known as 2019 novel corona virus, a single stranded positive sense RNA virus is the causative agent of COVID 19 disease. It mainly spreads via the respiratory route by means of aerosols. The objectives of our study were. To know the prevalence of ENT presentations in COVID 19 patients and to know the relationship between the symptoms and category of the disease as well as to know the relation between the blood group and recovery from the disease. The first 500 patients who were tested positive for COVID 19 and getting treated in our hospital were included in the study after taking written informed consent from the patients who were willing to participate in the study. A detailed history was taken from all the patients and more stress was given on the ENT symptoms with respect to its onset, duration and time taken for the relief of symptoms. The ENT symptoms were compared with the category of the disease as well as the blood group of the patients. Statistical analysis was done using Chi square test and Statistical Package for Social Sciences [SPSS] for Windows Version 22.0 Released 2013. Armonk, NY: IBM Corp., was used to perform statistical analyses. In our study 310 (62.0%) were males and 190 (38.0%) patients were females (38%), of age group ranging from 2 years to 87 years. In our study 367 (73.3%) patients were symptomatic and the rest 133 (26.6%) were asymptomatic. There were 335 (67.0%) patients in category A, 140 (28.0%) in category B and 25 (5.0%) in category C. The most common ENT presentation was headache and its prevelance was more in category C and it was of statistical significance. On comparing the blood group and the ENT symptoms occurrence of sore throat was of statistical significance and its prevelance was more among the O blood group patients. In terms of recovery from the disease the patients with blood group O had good recovery rate. Covid 19 pandemic is still an on going problem and newer strains of the virus are arising as well hence. In our study we found out that isolated ENT symptoms such as aguesia and anosmia were the only presentation of the disease. Thus they can be considered as early marker of the disease and it will be helpful in early detection and isolation of the patient as well as prevention of further spread of the disease.

Angiotensin-converting enzyme 2 and COVID-19: patients, comorbidities, and therapies

On March 11, 2020, the World Health Organization declared coronavirus disease 2019 (COVID-19) a pandemic, and the reality of the situation has finally caught up to the widespread reach of the disease. The presentation of the disease is highly variable, ranging from asymptomatic carriers to critical COVID-19. The availability of angiotensin-converting enzyme 2 (ACE2) receptors may reportedly increase the susceptibility and/or disease progression of COVID-19. Comorbidities and risk factors have also been noted to increase COVID-19 susceptibility. In this paper, we hereby review the evidence pertaining to ACE2's relationship to common comorbidities, risk factors, and therapies associated with the susceptibility and severity of COVID-19. We also highlight gaps of knowledge that require further investigation. The primary comorbidities of respiratory disease, cardiovascular disease, renal disease, diabetes, obesity, and hypertension had strong evidence. The secondary risk factors of age, sex, and race/genetics had limited-to-moderate evidence. The tertiary factors of ACE inhibitors and angiotensin II receptor blockers had limited-to-moderate evidence. Ibuprofen and thiazolidinediones had limited evidence.

Anxiety and Depression in Health Workers and General Population During COVID-19 in IRAN: A Cross-Sectional Study

BACKGROUND

The COVID-19 outbreak has exerted a great deal of psychological pressure on Iranian health workers and the general population. The aim of this study was to determine the effect of pandemic on anxiety and depression in Iranian population.

METHODS

An online cross-sectional study was conducted for the general public and healthcare workers in Iran using a questionnaire comprised of demographic questions and Hospital Anxiety and Depression Scale. Chi-square test and univariate and multivariate logistic regression models were conducted.

RESULTS

Of the 2045 participants, 1136 (65.6%) were considered to have moderate and severe anxiety symptoms, and 865 (42.3%) had moderate and severe depression symptoms. The prevalence of anxiety was higher in the females than in the males (OR = 1.4, 95% CI: 1.123-1.643, P = .002); the prevalence of anxiety was significantly higher in those aged 30-39 years than in other age-groups (OR = 1.6, 95% CI: 1.123-2.320, P = .001); furthermore, the prevalence of anxiety and depression was significantly higher in doctors and nurses compared with other occupations ((OR = 1.9, 95% CI: 1.367-2.491, P < .001) and (OR = 1.5, 95% CI: 1.154-2.021, P = .003)). In addition, the prevalence of anxiety symptoms in the likely infected COVID-19 group was higher than in the noninfected COVID-19 group (OR = 1.35, 95% CI: 1.093-1.654, P = .005).

CONCLUSIONS

Regarding the high prevalence of anxiety and depression symptoms, especially among healthcare workers, appropriate psychological/psychiatric intervention necessitates.

Distribution of the environmental and socioeconomic risk factors on COVID-19 death rate across continental USA: a spatial nonlinear analysis

The COVID-19 outbreak has become a global pandemic. The spatial variation in the environmental, health, socioeconomic, and demographic risk factors of COVID-19 death rate is not well understood. Global models and local linear models were used to estimate the impact of risk factors of the COVID-19, but these do not account for the nonlinear relationships between the risk factors and the COVID-19 death rate at various geographical locations. We proposed a local nonlinear nonparametric regression model named geographically weighted random forest (GW-RF) to estimate the nonlinear relationship between COVID-19 death rate and 47 risk factors derived from the US Environmental Protection Agency, National Center for Environmental Information, Centers for Disease Control and the US census. The COVID-19 data were employed to a global regression model random forest (RF) and a local model GW-RF. The adjusted R² of the RF is 0.69. The adjusted R² of the proposed GW-RF is 0.78. The result of GW-RF showed that the risk factors (i.e. going to work by walking, airborne benzene concentration, householder with a mortgage, unemployment, airborne PM_2.5 concentration and per cent of the black or African American) have a high correlation with the spatial distribution of the COVID-19 death rate, and these key factors driven from the GW-RF were mapped, which could provide useful implications for controlling the spread of the COVID-19 pandemic.

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.

Susceptibility to the novel coronavirus disease (COVID-19) is associated with ABO and Rh blood groups: a case-control study from Afghanistan

Background

There are preliminary studies about the association between COVID-19 and ABO phenotypes and the results are controversial. There are only two studies which investigated the association of Rh blood groups in addition to ABO with COVID-19; however, in the statistical analysis ABO and Rh blood groups have been considered separately. Therefore, the present case-control study was performed to determine the association of COVID-19 with ABO blood groups considering the Rh blood groups simultaneously. The study was conducted in Kunduz COVID-19 treatment specific center, Spin-Zar Hospital (Kunduz Province, North East Afghanistan). A total of 301 confirmed COVID-19 cases and 1039 healthy blood donors as control group were included in the study.

Results

The Rh- phenotype strongly increased the risk of COVID-19 (OR = 2.97, 95% CI 1.86-3.89, P < 0.001). Although blood group A increased the risk of developing COVID-19, the association did not reach statistical significance. In analysis of the combination phenotypes, the A- blood group remarkably increased the risk of COVID-19 (OR = 7.24, 95% CI 3.62-14.4, P < 0.001). Multivariate analysis revealed that the interaction of Rh and ABO is significant (P < 0.013).

Conclusion

These findings indicate that susceptibility to COVID-19 is strongly associated with A- blood group.

Association between ABO blood groups and susceptibility to COVID-19: profile of age and gender in Iraqi patients

Background

A case-control study was performed to examine age, gender, and ABO blood groups in 1014 Iraqi hospitalized cases with Coronavirus disease 2019 (COVID-19) and 901 blood donors (control group). The infection was molecularly diagnosed by detecting coronavirus RNA in nasal swabs of patients.

Results

Mean age was significantly elevated in cases compared to controls (48.2 ± 13.8 vs. 29.9 ± 9.0 year; probability [p] < 0.001). Receiver operating characteristic analysis demonstrated the predictive significance of age in COVID-19 evolution (Area under curve = 0.858; 95% CI: 0.841 - 0.875; p < 0.001). Males outnumbered females in cases (60.4 vs. 39.6%) and controls (56 vs. 44%). Stratification by age group (< 30, 30 - 39, 40 - 49 and ≥ 50 years) revealed that 48.3% of cases clustered in the age group ≥ 50 years. ABO blood group analysis showed that group A was the most common among cases, while group O was the most common among controls (35.5 and 36.7%, respectively). Blood groups A (35.5 vs. 32.7; corrected p [pc] = 0.021), A+AB (46.3 vs. 41.7%; pc = 0.021) and A+B+AB (68.0 vs. 63.3%; pc = 0.007) showed significantly elevated frequencies in cases compared to controls. Logistic regression analysis estimated odds ratios (ORs) of 1.53 (95% confidence interval [CI]: 1.16 - 2.02), 1.48 (95% CI: 1.14 - 1.93) and 1.50 (95% CI: 1.17 - 1.82) for blood groups A, A+AB and A+B+AB, respectively. Blood group frequencies showed no significant differences between age groups of cases or controls. Regarding gender, male cases were marked with increased frequency of group A (39.9 vs. 28.9%) and decreased frequency of group O (25.9 vs. 41.0%) compared to female cases. Independent re-analysis of ABO blood groups in male and female cases demonstrated that group A was increased in male cases compared to male controls (39.9 vs. 33.1%; OR = 1.65; 95% CI: 1.24 - 2.21; pc = 0.006). On the contrary, no significant differences were found between females of cases and controls.

Conclusions

The study results indicated that blood group A may be associated with an increased risk of developing COVID-19, particularly in males.