Response to toll-like receptor 9 (TLR9) stimulation of B cells from systemic lupus erythematosus (SLE) patients and healthy donors. B cells from SLE patients and healthy donors were purified and cultured with or without CpG. After 2 days of culture, the supernatants were collected and cytokine concentrations were measured by bioplex. Group 1 consists of certain cytokines with strong increase (>4-fold) upon TLR9 stimulation of B cells. Group 2 is composed of cytokines with a moderate increase (between 2- and 4-fold) upon TLR9 stimulation, while group 3 reflects cytokines with a very limited increase (<2 fold) after TLR9 stimulation (n =18 SLE patients). FGF, fibroblast growth factor; G-CSF, granulocyte colony-stimulating factor; G-CSF, granulocyte colony-stimulating factor; IP-10: IFNγ-induced protein 10; MIP, macrophage inflammatory proteins; PDGF-BB, platelet-derived growth factor-BB; RANTES, regulated on activation: normal T-cell expressed and secreted; VEGF, vascular endothelial growth factor.