Human Leukocyte Antigen as a Predictor of COVID-19 Severity

Since the spread of the coronavirus disease 2019 (COVID-19) pandemic, many countries have been suffering from the disease, and patients exhibit an extensive spectrum of symptoms from mild to severe, and in some cases, it leads to death. Identifying vulnerability factors may help detect very high-risk subjects to prevent disease mortality. Since people have different human leukocyte antigen (HLA) alleles, and the frequency of the alleles varies between different races and geographic regions, it is inferred that there is an association between HLA and the vulnerability of the population. The present study aimed to find the most frequent HLA alleles that profoundly affect COVID-19 outcomes. To find the relevant articles, medical databases (Medline, PubMed, EMBASE, Cochrane Library, and the like) were searched by the keywords, and the results related to the association between HLA and COVID-19 morbidity were selected and briefly presented. Regarding the extracted information from several studies, HLA alleles with a strong affinity to COVID-19 epitopes such as HLA-A*11:01, HLA-A*02:06, and HLA-B*54:01 could result in mild symptoms, while those with weak affinity such as HLA-B*44:06 and HLA-B*46:01 contributed to severe symptoms and high mortality rate. Further, heterozygosity and frequency of HLA alleles could affect the disease outcome within populations. As a result, the vulnerability of the patients can be predicted through their HLA pattern, and preventive measures can be taken instantly for populations expressing high-risk alleles. HLA can be assumed as a global predictor of COVID-19 disease outcomes. High frequent alleles which affect the outcome of the disease are introduced as susceptibility-determining alleles.