IL- 6 Gene (174G/C) Single Nucleotide Polymorphism as an Indicator of COVID-19 Severity in Egyptian Patients

The World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a public health emergency of international concern the epidemic has put public health systems under severe strain both in western countries and in the developing world. SARS-CoV-2 displays a more efficient transmission pattern when compared with SARS-CoV and MERS-CoV. Although the direct damage from the viruses contributes to the initiation of the disease, the cytokine storm caused by COVID-19 plays a vital role in the development of acute lung injury and adult respiratory distress syndrome.

IL-6, a kind of pleiotropic cytokine, is expressed by immune cells such as DC, monocytes, macrophages, B cells, and subsets of activated T cells, as well as by non-immune cells like fibroblasts, epithelial cells, and keratinocytes. It contributes to the pathogenesis of inflammatory or autoimmunity diseases. Excessive production of IL-6 leads to serious disease progression in viral infection. The IL-6 gene is located on chromosome 7 and several polymorphisms have been reported. The most frequently studied polymorphism is the single nucleotide polymorphism (SNP) 174C and - 174G in the promoter region, which has been associated with transcription rates of IL6. The incidence of IL-6-174C alleles is approximately 40%among the general Population. The G allele 174 SNP is coupled with the increased transcription upon endotoxin and IL-1β stimulation, IL-6 -174C allele carrier status is associated with higher level of IL-6 production and more severe forms of 4 pneumonia in general. This analysis strengthens the notion that IL-6 plays a pivotal role in novel coronavirus pneumonia (NCP) progression, it was IL-6-174 C allele rather than G allele that contributed to the risk of sepsis induced by Pneumonia