Abstract: Objective To examine the changes in the expression of pro-inflammatory and anti-inflammatory cytokines in the
peripheral blood mononuclear cells (PBMCs) and elucidate the inflammatory status of apparently healthy subjects. Methods
Peripheral blood samples (5 ml) were collected after fasting for more than 8 h from 14 healthy control subjects and 14
apparently healthy subjects with elevated serum high-sensitivity CRP (hsCRP) level (≥2.0 mg/L). PBMCs were separated by
Ficoll density gradient centrifugation and the total RNA was extracted for real-time quantitative PCR analysis of the
inflammatory cytokines, and plasma was separated for ELISA analysis of interleukin-6 (IL-6) and tumor necrosis factor-α
(TNF-α) expressions. Results The gene expressions of TNF-α and MCPIP were significantly increased in PBMCs of apparently
healthy subjects, while IL-6 and MCP-1 only showed slight elevations; IL-10 expression in PBMCs decreased significantly in
apparently healthy subjects as compared to that in the control group. The results of ELISA showed significantly elevated
TNF-α level without significant changes of plasma IL-6 level in apparently healthy subjects. Conclusion In apparently healthy
subjects with normal lipid levels, chronic low-grade inflammation has occurred shown by elevated expressions of the
pro-inflammatory cytokines and lowered expressions of the anti-inflammatory cytokines.