title: An ultrasensitive system to detect IL-4: enzyme-linked immunosorbent assay (ELISA) combined with an avidin-biotin and enzyme amplification system.
abstract: We established an ultrasensitive interleukin-4 enzyme-linked immunosorbent assay by combining ELISA with an avidin-biotin and enzyme amplification system. The resultant system (AB-EA ELISA) was 250 times more sensitive than conventional ELISA and 2.5 times more sensitive than enhanced ELISA using an enzyme amplification system alone. The ultrasensitive assay was specific to IL-4 alone; there was no cross reaction with other cytokines. Using the ultrasensitive assay, we measured IL-4 synthesis in vitro by unstimulated and stimulated peripheral blood mononuclear cells (PBMC) from patients with allergic rhinitis. PBMC from patients spontaneously produced measurable amounts of IL-4, whereas IL-4 production from PBMC of normal controls, if any, was below detectable levels. Stimulation of the cultures with LPS significantly increased IL-4 production in two of six patient PBMC cultures but in none of the control cultures; stimulation with Con A markedly increased IL-4 production in all patient PBMC cultures but in only two of seven control cultures. These results suggest that the AB-EA ELISA is a useful method to study the mechanism of IL-4 synthesis in type-I allergic diseases.
authors.affiliation: Internal Medicine I, National Defense Medical College, Saitama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishizuka
authors.forename: M
authors.initials: M
authors.lastname: Kawagoe
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: M
authors.initials: M
authors.lastname: Harigai
authors.forename: M
authors.initials: M
authors.lastname: Kawakami
authors.forename: Y
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: T
authors.initials: T
authors.lastname: Hidaka
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuki
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D001360:Avidin; D001710:Biotin; D004797:Enzyme-Linked Immunosorbent Assay; D015847:Interleukin-4 / Q000032:analysis* / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000737:chemistry / Q000378:metabolism; D011817:Rabbits
chemical_list: D001360:Avidin; D015847:Interleukin-4; D001710:Biotin