Association of Monocyte–Macrophage Chemotactic Receptor 2 Gene Polymorphisms with Covid-19 Infection in Karbala, Iraq

Abstract Background: Between 2019 and early 2020, the appearance of an unusual strain related to the coronavirus caused a worldwide pandemic. During this infection, the immune response by different types of cells can trigger the creation of monocyte–macrophage chemotactic receptors to facilitate monocyte infiltrates CCL2/CC chemokine receptor 2 (CCR2) pathway. Objectives: This research aims to investigate the relationship between polymorphisms and serum levels of CCR2 in patients infected with COVID-19 and its association with the development of symptoms. Materials and Methods: A total of 150 SARS-CoV-2 infected patients and 50 healthy controls participated in the study. Real time PCR for viral swabbing and strip antigens confirmed the diagnosis. Participants received medical care at IMAM Al-Hussein Medical City from March to July 2022; the mild group included 36 men and 14 women. Nonetheless, 31 men and 19 women were in moderate and severe groups, and the average age was (44.04, 62.16, and 61.14 years) for the three groups. Then, the manufacturer’s instructions for CCR2 level parameters used sandwich ELISA and allele-specific primers assay for CCR2 receptor (rs1799864) polymorphisms. Results: A study of CCR2 in human serum found a positive correlation and significance ( r = 0.564, p ≤ 0.001) with COVID-19 symptoms. However, CCR2 polymorphisms in mild, moderate, and severe groups were nonstatistical for SNP (rs1799864), which raised the odds ratio with increased symptoms; Heterozygote mutant GA allele (rs1799864) was more frequent and increased odds ratio in patients’ groups; therefore, it was considered a risk factors development of symptoms COVID-19. Conclusion: Both parameter studies are the polymorphisms and level CCR2 raised in individuals suffering from COVID-19.