To investigate the intra- and extracellular levels of various cytokines and chemokines in CSF in chronic inflammatory demyelinating polyneuropathy (CIDP) and vasculitic neuropathy (VN), 16 cytokines, IL-1beta, IL-2, 11-4, IL-5, IL-6, IL-7, IL-8, IL-10, 11-12 (p70), IL-13, IL-17, IFN-gamma, TNF-alpha, G-CSF, MCP-1 and MIP-1beta, were measured in CSF supematant by a multiplexed fluorescent bead-based immunoassay and intracellular production of IFN-gamma and IL-4 in CSF CD4+ T cells were simultaneously measured by flow cylonveiry, in 14 patients with CIDP, 8 patients with VN and 25 patients with other noninflammatory neurologic diseases (OND). In the CSF supematant, a significant increase of IL-17, IL-8 and IL-6, and a significant decrease of 11-4. IL-5 and IL-7 levels were detected in pretreated CIDP as compared with OND. A significant increase of IL-6, IL-8 and IL-10 levels was found in pretreated VN. Both IL-7 and IL-8 levels correlated strongly with CSF protein levels in CIDP. although the correlation of IL-6 levels was weak. In CSF CD4+ T cells IFN-gamma(+) IL-4(+) cell percentages were markedly elevated in CIDP compared with OND, but not in VN. resulting in a significant increase of intracellular IFN-gamma/IL-4 ratio in CIDP, even in the absence of CSF pleocytosis. The nonresponders to intravenous immunoglobulins (IVIGs) showed a significantly lower IFN-gamma(-) IL-4(+) CD4+ T cell percentage, and tended to have a higher intracellular IFN-gamma/IL-4 ratio than the responders in CSF. Marked upregulation of Th1 cytokine, IL-17. and downregulation of Th2 cytokines, together with infiltration of IFN-gamma-producinq CD4+ T are useful markers for CIDP, while several Th2 cytokines are upregulated in VN in CSF. (C) 2004 Elsevier B.V. All rights reserved.