Histamine release with a solid-phase-coupled allergen.

Mite allergen was coupled to Sepharose, paper disk or microcrystalline cellulose, and the immobilized allergen was used for histamine release assay in human leukocytes. In terms of the spontaneous release and the reproducibility, the histamine release assay using immobilized allergen was comparable to that using soluble allergen. Histamine release increased progressively with the concentration of the immobilized allergen up to maximal release of histamine which persisted with further increase in immobilized allergen. Histamine release with soluble allergen decreased at higher concentrations of the allergen. The concentration of immobilized allergen required for maximal histamine release was the same as that with soluble allergen, but the maximal release with immobilized allergen was always about 20% lower than that with soluble allergen. Histamine release was not dependent on the density of allergen molecules on Sepharose beads. Although there was a significant correlation between histamine release obtained with a commercial disk, with a disk prepared in our laboratory, and with soluble allergen, the magnitude of the release by both assays using a paper disk was reduced significantly.