Association of human leukocyte antigen class II alleles with epithelial cell apoptosis and extracellular matrix production in acute COVID-19.

INTRODUCTION

Pathogenic mechanisms and long-term consequences of COVID-19 require attention in studies on SARS-CoV-2. The association of the severity of COVID-19 with genetic factors, such as human leukocyte antigen (HLA) genes, remains underexplored. Our study assessed the relationships between HLA class II alleles and COVID-19 severity and blood-based indicators of systemic inflammation and organ damage, serum markers of epithelial cell apoptosis such as caspase-cleaved CK18 fragment M30 (CK18-M30) and the extracellular matrix product hyaluronic acid (HA).

MATERIAL AND METHODS

The study included 101 hospitalized COVID-19 patients (mean age 60 ±14 years). Clinical tests were performed at admission to the hospital. The levels of CK18-M30 and HA were detected in serum by enzyme-linked immunosorbent assay (ELISA). HLA typing was performed in HLA-DRB1, -DQA1, and -DQB1 loci by the polymerase chain reaction with low-resolution sequence-specific primers.

RESULTS

Sixty-one patients had a non-severe and 40 had a severe or critical disease course (following the WHO definition). The severity was associated with older age, male gender, higher HA, CK18-M30, and some indicators of inflammation. Despite the lack of direct association between HLA alleles and the severity of COVID-19, the presence of HLA-DRB104 and 12 alleles in the genotype was associated with lowered or elevated HA, respectively. The HLA-DQB103:01 allele was associated with lowered CK18-M30, aspartate aminotransferase, and ferritin. In addition, HLA-DQB1*06:01 was associated with elevated alanine aminotransferase.

CONCLUSIONS

Associations of HLA class II alleles with markers of epithelial cell apoptosis and extracellular matrix production indirectly support the influence of HLA genes on acute COVID-19 severity.