DETERMINATION OF TUMOR-NECROSIS-FACTOR-ALPHA AND INTERLEUKIN-10 PRODUCTION IN A WHOLE-BLOOD STIMULATION SYSTEM - ASSESSMENT OF LABORATORY ERROR AND INDIVIDUAL VARIATION

Ex vivo production of cytokines as determined by whole blood stimulati on and supernatant ELISA is partly determined by heritability. To asse ss the ability of this system to distinguish between high and low prod ucers the laboratory error and individual variation were investigated. Whole blood samples from healthy volunteers were collected using endo toxin-free tubes and were incubated with 0 to 1000 ng/ml lipopolysacch aride concentrations for 4 and 24 h, and subsequently centrifuged. In the supernatants, TNF-alpha and ILIO were measured by ELISA. Coefficie nts of variation for the day-to-day variation in the blood sampling, t ransport and stimulation as well as in the whole blood stimulation per se ranged from 7.5% to 12.3%. The intra-individual variation was 15% (TNF-alpha) and 19% (IL10) in contrast to the inter-individual variati on of, on average, 35%. No interchanging of ranks between high and low producers was observed after repeating the whole blood stimulation on distinct days. The whole blood stimulation system is able to distingu ish high and low producers of TNF-ol and ILIO. (C) 1998 Elsevier Scien ce B.V. All rights reserved.