COVID-19 and Blood Groups: A Six-Months Observational Study in Ferrara, Italy

Abstract

The current literature still gives a little information about the relationships between the ABO blood group system and the immune response to the virus or the different disease outcomes. Hypothesizing the presence of a predisposition by some blood groups to COVID-19, we searched for differences between patients towards the different outcomes of disease.We enrolled 330 inpatients with a diagnosis of COVID-19, determining both their ABO blood group system and Rh factor, collecting demographic, clinical and laboratory data. We searched for relationships with COVID-19 outcomes within an observation period of 180 days (Intensification of Care - IoC, Inhospital death, 180-days mortality). The most frequent ABO blood group was A (45.8%); a minor part was represented by group O (38.8%), B (11.5%), AB (3.9%). As for the Rh factor, 86.7% of patients were Rh-positive. There were no significant differences between blood groups and Rh factors as for age, length of hospital stays (LoS), or Charlson Comorbidity Index (CCI), nor we found significant relationships between the ABO groups and COVID-19 outcomes. A significant relation was found between AB group and IoC (p=0.03) while as for the Rh factor, the patients with Rh factor positive died with less frequency during the stay (p=0.03). Cox regression analyses showed substantial differences in the survival functions concerning the Rh factors. The Rh factor seems to be involved in the 180-day prognosis. The survival functions of patients with Rh factor positive show, in fact, significantly better curves when compared to those with Rh factor negative.

Psychomotor and neurofunctional aspects after COVID-19

“…The present data on blood types of subjects affected by COVID-19 apparently only reflected the distribution of blood types in the Brazilian population, with no relationship with contamination and severity of symptoms. To answer whether the Rh factor would be decisive, as mentioned by Greco and colleagues (Greco et al, 2021), results were analysed, but, again, there was no evidence of a greater prevalence in one of the Rh factors.…”

“…The studies about COVID-19 and blood types are somehow contradictory. There is evidence that there may be greater complications in some blood types (Zhao et al ., 2021), some studies point to an issue only related to the Rh factor (Greco et al ., 2021), and some experts argue that there is no relationship. The present data on blood types of subjects affected by COVID-19 apparently only reflected the distribution of blood types in the Brazilian population, with no relationship with contamination and severity of symptoms.…”

A large cohort study of the effects of Lewis, ABO, 13 other blood groups, and secretor status on COVID‐19 susceptibility, severity, and long COVID‐19

“…10 However, limitations of these previous studies include, for example, matching patient cases with blood donor controls 4,10 and small cohort sizes. 13,14,16,17 In addition, so far, few studies have looked at the effects of the many existing blood groups beyond ABO and Rh.…”