ABO Blood Group Profile Frequencies and Relationship in COVID-19 Disease Susceptibility and Severity in Lagos, Nigeria

et al [14]. Another report from a study done in Mauritania, Morocco, Cameroun, Tunisia, Ethiopia and Iran is also consistent with the Nigerian study showing [O > A > B > AB] Hamed, et al. [16-21]. The report from Madagascar and Guinea showed slightly different result [O > B > A > AB]. However, Nigerian ABO blood group results are slightly different from the study in Madagascar and Guinea that reported this trend [O > B > A > AB] Randriamanantany, et al. [22,23]. Reports from studies in India and Bangladesh showed blood group B having highest prevalence followed by O and the least was AB [B > O > A > AB] Dewan, et al. [24,25]. In Nigeria, there is a limited information of association between ABO blood groups and the susceptibility to COVID-19 in Nigeria. This study therefore, evaluated the role of ABO blood group in SARS-CoV- 2 infection susceptibility and disease severity in Lagos, Nigeria. Conclusion: There is no statistical significance between the blood group profiles in association with SARS CoV-2 severity from this preliminary report. However, the patients having blood group B may have a higher risk of persistent positivity having the highest prevalence among those who had moderate SARS-CoV-2 disease [41.9%]. Further studies on the individuals with confirmed exposure to COVID-19 infection may reveal better association.


COVID-19 caused by the Severe Acute Respiratory Syndrome
Coronavirus-2 [SARS-CoV-2] was first described as a serious infection leading to significant morbidity and mortality in Wuhan, China in January 2020 Zhou, et al. [1]. The number of deaths was increasing due to the catastrophic effect of the emerging new strains. Research has shown that there are predicting factors of COVID-19 severity such as demographic, clinical, immunologic, haematological, biochemical, and radiographic factors Benjamin, et al. [2]. According to Samra, et al. [3] ABO groups can play a role in COVID-19 severity and susceptibility. The rapid global spread of the novel coronavirus SARS-CoV-2 has strained existing healthcare and testing resources, and it is causing COVID-19 severe cases in some people than in others. While some people experience only mild symptoms, others are being hospitalized Samra, et al. [3]. The pathogenesis of severe COVID-19 and the associated respiratory failure are still unclear, but the higher mortality rate is consistently associated with older age and being male Samra, et al. [3]. Many studies have shown that the ABO blood type is a potential risk for various diseases such as cancer, myocardial infarction, acute kidney injury, and venous thromboembolism Dentali, et al. [4,5] Apart from comorbidities and other predicting factors, findings have shown that the ABO blood group has a correlation with COVID-19 susceptibility and severity. Biological factors that determine susceptibility to SARS-CoV-2 and severity of COVID-19 are yet to be fully understood Samra, et al. [3]. The ABO blood grouping may influence the susceptibility of COVID-19 and severity of the disease Zhao, et al. [6]. As reported by Nagla, et al [7], patients from three hospitals in Wuhan, Shenzhen, and China showed the likelihood of association between ABO blood groups and the susceptibility to COVID-19 exposure after the outbreak of the COVID-19 infection. The study results showed that individuals with blood group A had a markedly greater risk of COVID-19 exposure, while those with blood group O had a significantly reduced risk of COVID-19 infection. In a meta-analysis of two different case-control cohorts, blood group A was reported to confer a greater risk of aggravated COVID-19, while blood group O offer protection against COVID-19 infection WU, et al. [8].
However, A, B and O blood group are antigenic complex oligosaccharide molecules located on the extracellular surface of the red blood cell membrane Storry JR, et al. [9]. ABO blood group are also expressed on the surface of other human cells and tissues, including the epithelium, sensory neurons, platelets, and the vascular endothelium Eastlund [10]. The ABO blood group have been reported to play a key role in various human diseases such as diabetes, cardiovascular, neoplastic, carcinoma and other infectious disorders Cheng et al. [11][12][13]. ABO and Rh blood groups polymorphism are valuable and indispensable tools in contemporary medicine, population genetics and anthropology. The distribution of these two blood groups has been reported different populations of the world and they showed considerable variation in different geographic locations, reflecting the underlying genetic and ethnic diversity of human populations Garratty ,et al. [14,15] reported the distribution and gene frequencies of ABO and Rh  [24,25]. In Nigeria, there is a limited information of association between ABO blood groups and the susceptibility to  in Nigeria. This study therefore, evaluated the role of ABO blood group in SARS-CoV-2 infection susceptibility and disease severity in Lagos, Nigeria.

Conclusion:
There is no statistical significance between the blood group profiles in association with SARS CoV-2 severity from this preliminary report. However, the patients having blood group B may have a higher risk of persistent positivity having the highest prevalence among those who had moderate SARS-CoV-2 disease [41.9%]. Further studies on the individuals with confirmed exposure to COVID-19 infection may reveal better association.

Study Design and Participants
This study is a case series that includes patients that are

Results
A total of 697 COVID-19 patients were included in this study.  Figure   1 showed the blood groups that accounted for COVID-19 severity:       A recent study that supported our data reported that a significantly increased risk was associated with blood group B Almadhi, et al. [28], which is also comparable to findings by Latz, et al. [29] and meta-analysis by Liu, et al. [30].

Conclusion
The ABO blood group was not associated with the presentation and recovery period of COVID-19 disease during the period of this study. However, the patients of blood group B profile seem to have

Availability of Supporting Data
Besides those presented in the study, there are no other supporting data for this manuscript.

Competing Interests
The authors report no competing (commercial/academic) interests.

Ethical Approval
Approval to conduct this study was received from the Institutional Review Board (IRB) at NIMR, Yaba, Lagos.

Funding
This study was funded by the Nigerian Institute of Medical Research, NIMR (Grant Number: NMG-CIF-06-0024). The PI and co-authors financed this study.