Diagnostic relevance of CSF interleukin-6

Abstract: In 1985 interleukin 6 (IL-6) was first identified as a differentiation factor for B-cells (B-cell stimulatory factor 2) which caused B-cells to mature and produce antibodies. Numerous studies now demonstrate the pleiotropic character of IL-6, which has been shown to possess important functions in the immune system, the regulation of hematopoesis, inflammation and oncogenesis. In the central nervous system (CNS), IL-6 is involved in neurogenesis and the response of neurons and glia-cells to various injuries. CNS infections, cerebral ischaemia, CNS traumata or chronic inflammatory diseases with CNS manifestations such as neuro-lupus or neuro-sarcoidosis are associated with increased IL-6 levels in the cerebrospinal fluid (CSF). Thus, the use of IL-6 as a diagnostic and prognostic tool in these diseases is being investigated. In this review we aim to provide an overview of current studies and evaluate the diagnostic significance of CSF-IL-6.