OBJECTIVETo 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.

METHODSPeripheral 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.

RESULTSThe 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.

CONCLUSIONIn 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.