Production of tumor necrosis factor α in healthy donors and rheumatoid arthritis patients after lipopolysaccharide and lipoteichoic acid cultures. Whole blood of healthy donors (HDs) (n = 4) and rheumatoid arthritis (RA) patients (n = 12) collected before adalimumab treatment was cultured in the presence of lipopolysaccharide (LPS; 1 μg/ml) or lipoteichoic acid (LTA; 10 μg/ml) for 4 hours to analyze intracellular tumor necrosis factor α–phycoerythrin (iTNFα-PE) and membrane tumor necrosis factor α–phycoerythrin (mTNFα-PE) by flow cytometry and for 24 hours to analyze levels of TNFα in supernatants by ELISA. (A) iTNFα and (B) mTNFα were analyzed in monocytes from LPS and LTA cultures gated according to CD14 expression. Levels of TNFα in culture supernatants of LPS (C) and LTA (D) were analyzed in HDs and RA patients. A t-test was used for statistical analysis.