CD4 and viral infectious disease: The increase in serum levels of NLR indicates an imbalance in the inflammatory response where inflammatory factors related to viral infection, such as interleukin-6, interleukin-8, and granulocyte colony-stimulating factor, stimulate neutrophil production (47) and, in contrast, systemic inflammation accelerates lymphocyte apoptosis, depresses cellular immunity, decreases CD4+, and increases CD8+ suppressor T-lymphocytes (51, 52).