Cytokine
production by PBL and T cells of allergic patients stimulated with allergens
measured with the Th1/Th2 cytometric bead array kit
(CBA)
ALK-Abello, Hørsholm
Measuring cytokines in cell cultures are an important
source of information describing dominant type(s) of reaction(s). The primary
assays used are in vitro PBL cultures, allergen specific T-cell lines
and clones which are tested against the relevant allergens. Even though a
standard proliferation assay will provide some information we are also
interested in whether the reaction is of a regulatory T-cell, Th1, Th2 or
general inflammatory character. Cytokines detectable by the Th1/Th2 cytometric bead array kit from BD Bioscience can measure
the following cytokines in ONE sample using less than 50 µl culture of
supernatant: IFN-gamma (Th1), TNF-alfa
(inflammatory), IL-10 (regulatory), IL-5 and IL-4 (Th2) and IL-2 (growth
factor).
This sounds too good to be true so we tested the kit
against ELISAs, which did not show exactly the same
results but the results were more consistent using the CBA kit. However, the
CBA assay is very sensitive to BOTH light and heat (room temperature).
Fortunately, by keeping samples on ice and in the dark the problem is
considerably reduced. Speed and cost is reduced by using half the volume at all
times during the procedure described by BD Bioscience and by counting 900 beads
instead of the 1800 recommended.