Validation of an automated enzyme immunoassay for interleukin-6 for routine clinical use

Serum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are incre ased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a sin gle measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core(R) immunological analyzer (Roche Diagnostic Systems) which enables sin gle IL-6 measurement within about 1 hour. The automated assay correlates we ll with an established, manual microtiter plate assay (Biosource GmbH) whic h uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international refer ence preparation. Recovery of the international standard was in the range o f 92-104%. The automated assay had a precision of singletons below 6% and w as linear up to 2800 pg/ml. This automated assay provides a suitable, conve nient and time saving method for measurement of IL-6 serum levels in the ro utine clinical laboratory.