Association of Human Leucocyte Antigen Polymorphism with Coronavirus Disease 19 in Renal Transplant Recipients

Human leucocyte antigens (HLAs) are highly polymorphic glycoproteins expressed at the surface of all nucleated cells. It is required for the SARS-CoV-2 peptide antigen presentation to immune cells for their effector response. However, polymorphism in HLA significantly impacts the binding of SARS-CoV-2 antigenic peptide to the HLA pocket and regulates immune activation. In this study, 514 renal transplant recipients (RTRs) were recruited from the outpatient department and categorized either into symptomatic (n = 173) or asymptomatic groups (n = 341) based on Coronavirus disease-19 (COVID-19) symptoms. The anti-SARS-CoV-2 spike protein-specific IgG antibody titer was measured by chemiluminescent microparticle immune-assay methods in 310 RTRs. The HLA details of 514 patients were retrieved from the electronic medical records and analyzed retrospectively. We found that HLA antigen allele A*24 was significantly associated with asymptomatic infection in 22.78%, HLA C*02 in 4.51%, DRB1*12 in 10.85%, and HLA DQA1*02 in 27.74% of RTRs. Whereas HLA A*29 in 3.46%, A*33 in 26.01%, B*13 in 10.40%, DRB1*10 in 4.62%, DRB1*15 in 39.30%, DRB1*30 in 1.15%, and DQA1*60 in 3.57% of RTRs were associated with symptomatic infection. HLA DRB1*13 and DRB1*15 were associated with moderate to severe degrees of COVID-19 disease. The seroconversion rate in asymptomatic patients was 118/137 (86.13%), had a median titer of 647.80 au/ml, compared to symptomatic patients 148/173 (85.54%) with a median titer of 400.00 au/ml, which was not significant between the two groups (P = 0.88 and 0.13). In conclusion, HLA alleles A*24, C*02, DRB1*12, and DQA1*02 were significantly associated with asymptomatic infection, and A*29, A*33, B*13, DRB1*10, DRB*15, and DRB1*30 were significantly associated with symptomatic infection. HLA DRB1*13 and DRB1*15 were associated with moderate to severe degrees of COVID-19 disease.