Blood groups and secretory state in COVID-19

INTRODUCTION: Despite the achievements of modern medicine, healthcare system is lacking in knowledge about the new coronavirus infection caused by the SARS-CoV-2 virus. AIM: To establish the relationship of the new coronavirus infection with the blood group according to the AB0 blood system in the Samara region and assess the secretory status of the oral fluid in patients with COVID-19. MATERIALS AND METHODS: This study was conducted from June 2019 to December 2020, and included 89 healthy individuals (38% males, 62% females, average age 24 ± 2.5 years) and 92 patients with COVID-19 (24% males and 76% females, average age 55.68 ± 1.83 years). The material for the study was oral fluid and venous blood. Determination of the blood group according to the AB0 system was carried out by a cross method, the secretory status of saliva according to the I. Vidas method. Descriptive methods were used for statistical data processing (arithmetic mean, error of the mean), calculation of the percentage of a whole number using computer programs IBM SPSS Statistics 23 and Microsoft Office Excel 2010. RESULTS: The distribution by blood group in patients with COVID-19 was as follows: A (II) blood group was found in 43.5%, O (I) in 36.9%, B (III) in 17.4%, AB (IV) in 2.2%. Rh-positive status was determined for 92.4%. Among secretory representatives, antigen A was secreted in 92.1%, and antigen B was secreted in 7.9% of cases. Antigens A and B were absent in the oral fluid of patients with AB (IV) blood group. CONCLUSIONS: This study confirmed the prevalence of A(II) blood group carriers among patients with COVID-19. In this case, the secretion of antigen A into the oral fluid is 92.1%. Group A antigen, being a glycoprotein, can act as a factor facilitating the mechanism of penetration of the SARS-CoV-2 into the human body. The results of the study indicate the need for a personalized approach at the stage of diagnosis and monitoring of the treatment of new coronavirus infection, as well as taking into consideration the blood group to develop preventive measures for COVID-19.