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.