Adding spotlight on the interplay between Covid-19 and the host’s immune system: The case of the HLA partner

Abstract

Background: COVID-19 has varying susceptibility, severity, and mortality rates across different patients’ populations.  We aim to investigate any possible impact of HLA polymorphisms on disease’s clinical course. Method and Material: One hundred thirty-three previously affected individuals of Greek origin, were tested for anti-SARS-CoV-2 IgG and IgA antibody titers and had HLA high resolution typing. Among them, ninety did not require hospitalization (O1), whereas thirty-three were hospitalized (O2). The following parameters were investigated: frequency of occurrence of various HLA alleles, variations between the two groups, correlations between anti-SARS-CoV-2 IgG and IgA antibody titers, HLA polymorphisms and disease’s clinical severity. Results: We report higher frequency of expression of HLA - A*24:02 (p=0.0176), A32:01 (p=0.0127), A*68:01 (p =0.0205), DRB1*16:01 (p=0.0067) in the O1 subgroup and higher frequency of expression of HLA-A*03:01 (p=0.0067), A*31:01 (p=0.0082) and B*47:01 (p=0.0265) alleles in the O2 subgroup. Among participants with HLA*A24:02 expression, IgG antibody levels were higher in the O1 subgroup compared to the O2 subgroup (p=0.0000157). Conversely, the average titers of IgG and IgA anti-SARS-CoV-2 antibodies were higher in the O2 compared to the O1 subgroup (p=0.00006 and 0.000341, accordingly). Conclusions: This work brings light to the complex interplay between the virus and host’s immune system, suggesting that genetic defined parameters may play a role on disease’s clinical course. More relevant efforts are required in a global scale level to further investigate this complicated issue.