BIOASSAY VS IMMUNOASSAY FOR QUANTIFICATION OF INTERLEUKIN-6 IN BIOLOGICAL-FLUIDS

As several possible prognostic and therapeutic applications of interle ukin-6 are currently under trial, the available methods for its quanti fication in biological fluids should be evaluated. In this report, the 7TD1 hybridoma bioassay is compared to an enzyme immunoassay for the determination of interleukin-6 in serum and plasma of normal subjects and patients with cancer, sepsis, and systemic lupus erythematosus, as well as in malignant pleural effusions and culture supernatants. The results show a good correlation between the two methods in all cases. Mean values of the examined groups were statistically different betwee n the assays only in the case of septic patients. This may be attribut ed either to the influence of other molecules on the assays or to the nonlinearity of the dose-response curves. Since immunoassays are easie r to perform, it seems that they are more suitable for routine use, th e bioassay being preferable in cases where increased sensitivity is re quired. (C) 1995 Wiley-Liss, Inc.