TNF alpha, IFN gamma and IL-2 mRNA expression in CIDP sural nerve biopsies

Proinflammatory cytokines contribute to the regulation of the disease proce ss in inflammatory neuropathies. Cellular localisation of cytokine expressi on in CIDP nerve biopsies should provide further insight into the pathogeni c mechanisms of the disease and the individual cells involved. In this stud y in situ hybridisation was used to determine the exact localisation and id entity of cells that express TNF alpha, IFN gamma and IL-2 mRNA within the CIDP nerve. Paraffin embedded and frozen sural nerve biopsies from three ac ute phase CIDP patients were used for the study. Sections of these samples were probed with digoxigenin labelled oligoprobes for TNF alpha, TFN gamma and IL-2, The results demonstrate localisation of cytokine expression to th e inner rim of the perineurium, epineurial and endoneurial blood vessels an d infiltrating inflammatory cells. In addition strong staining for TNFa mRN A was widespread in the endoneurium in areas consistent with/suggestive of Schwann cells. Expression of cytokines in the perineurium and endoneurial b lood vessels may have pertinent implications with respect to the breakdown of the blood nerve barrier associated with CIDP. In the very least the pote ntial for an immunomodulatory role may be ascribed to these cells. (C) 1999 Elsevier Science B.V. All rights reserved.