The Effect of Blood Type on Risk for COVID-19 Infection

Specific blood types are associated with a higher risk for SARS-CoV-2 infection and may alter lipid metabolism, according to a study published in Metabolic Syndrome and Related Disorders.

Several risk factors have been established for COVID-19 susceptibility, including age, diabetes, and obesity. Recent studies have found an association between certain blood groups and higher risk and mortality for COVID-19, although they offer conflicting results. Additionally, viral infections have been shown to alter lipid metabolism.  As such, researchers aimed to evaluate the lipid profile and ABO blood typing in the susceptibility, morbidity, mortality, and prognosis of SARS-CoV-2 infection.

A cross sectional study was conducted on a cohort of individuals with COVID-19 who were compared with matched controls without infection. Individuals were recruited from 2 sites: Universidade do Extremo Sul Catarinense (UNESC, Criciu ́ma, Brazil), and Universidade Federal da Fronteira Sul (UFFS, Chapeco ́, Brazil). Individuals who were aged between 18 and 90 years, living in Brazil, and who had a diagnosis of COVID-19 were included in the study. Individuals who were diagnosed with bipolar disorder, or who had a physical or cognitive condition that limited their ability to understand questionnaires were excluded from the study.

Venous blood was analyzed from each participant for SARS-CoV-2 antibodies, ABO blood group and Rh factor analysis. Additionally, serum levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides were also obtained.

A total of 350 individuals (114 with COVID-19 and 236 control patients) were included in the final study. Researchers found a higher risk of COVID-19 infection in patients who were in blood group A, compared with blood group B (odds ratio [OR], 2.819; 95% CI, 95% CI, 1.089-7.301; P =.028). Compared with other blood groups, blood group A was also associated with a higher risk for COVID-19 infection (OR, 1.747; 95% CI, 1.099- 2.778; P =.018). Upon evaluating Rh factor, individuals with blood type A- had a higher chance of having COVID-19, compared with other blood groups (OR, 2.463; 95% CI, 1.115–5.443; P =.022). Individuals with moderate/severe symptoms also were more likely to have a higher body mass index (BMI; 31.13±8.23; n=19), when compared with those with mild symptoms (26.67±4.62; n=88; P =.033).

Stratifying blood groups in relation to symptom severity found that the O+ blood group to has a higher chance of moderate/severe symptoms, when compared with other blood groups (OR, 2.941; 95% CI, 1.123-7.701; P =.025). Although blood type A was associated with a higher risk for COVID-19 infection, those affected had a lower chance of having moderate/severe symptoms (OR, 0.29; 95% CI, 0.10–0.81; P =.015).

Of note, serum analysis found that individuals with COVID-19 presented with higher triglyceride levels (209.93±140.21), when compared with control patients (164.92±89.54, P =.002). Additionally, those infected with COVID-19 presented with lower HDL-C levels (41.17±10.20), when compared with control patients (44.11±11.14, P =.019).

“Findings of this study suggest that blood type may play a role in susceptibility and severity to SARS-CoV-2 infection, with blood type A being more susceptible to infection and blood type O having a greater vulnerability to the development of moderate/severe symptoms, proposing that blood type may be involved with disease progression,” the study authors wrote. “…more longitudinal studies are needed to fully understand the underlying molecular mechanism between ABO blood group system and the correlation between the composition, structure, and function of lipid components in the pathophysiology of COVID-19”.