Association of HLA-B gene polymorphism and blood groups with COVID-19 susceptibility and severity

The COVID-19 pandemic gave insight into how host genetics influence the ability to get infected and how severe the infection will be if contracted. Among these, the HLA polymorphisms and ABO blood groups are known to influence the immune system. This study examines the correlation between HLA-B genotypes, blood groups, and the severity of COVID-19. A total of 984 COVID-19 patient samples and control samples were collected from different regions of Pakistan. Throat and nasopharyngeal swabs were obtained for molecular detection of SARS-CoV-2, and blood samples were collected for HLA-B genotyping and ABO blood group analysis. Genomic DNA was extracted using the Phenol-Chloroform method, and HLA-B genotyping was performed using the OLERUP SSP HLA typing kit. The study identified a significant association between HLA-B07:02 and increased COVID-19 susceptibility (OR: 2.5, 95% CI: 1.6-3.9, p < 0.001), whereas HLA-B15:01 was associated with a protective effect (OR: 0.6, 95% CI: 0.4-0.9, p = 0.01). Blood group A was also linked to higher infection risk, while blood group O conferred protection. A strong correlation was observed between co-morbidities (hypertension, diabetes) and severe COVID-19 outcomes. This study provides convincing evidence that HLA-B polymorphisms and ABO blood groups play a significant role in COVID-19 susceptibility and severity.