title: Interleukin-6 is released in the cutaneous response to allergen challenge in atopic individuals.
abstract: The mechanisms responsible for cutaneous response to antigen are complex. Interleukin-1 (IL-1) and interleukin-6 (IL-6) are proinflammatory cytokines that share many properties. Previous studies with a blister-chamber model have demonstrated IL-1 to be produced in the cutaneous response to antigen. Since IL-2 production by activated T cells and IL-6 production by macrophages are both stimulated by IL-1, we hypothesized that IL-2 and IL-6 may be involved in the cutaneous late-phase response (LPR) to antigen. We examined antigen-challenged sites for IL-2 immunoreactivity (ELISA) but found no difference between antigen- and diluent-challenged skin sites (N = 4). Since IL-2 has been demonstrated to be produced in response to IL-1 and IL-1 activity has been demonstrated to be greatest between hours 10 and 12, we speculated that IL-2 might not be detected until after hour 12. We were unable to demonstrate any increase in IL-2 production, even by extending our studies to 24 hours in two subjects. Antigen-challenged, skin blister-chamber fluids from atopic subjects demonstrated the appearance of IL-6 (ELISA) in pooled samples representing hours 1 1/2, 3 1/2, 5 1/2, and 7, but not at diluent control sites (p less than 0.05; N = 6). IL-6 reached a median peak of 0.66 ng/ml at 3 1/2 hours. Median levels of IL-6 fell to baseline at 8 hours, followed by a second peak of 0.25 ng/ml at hour 10. Three distinct patterns of IL-6 release were noted: early release of IL-6 followed by a sustained slower rise that peaked at hour 9 before declining to baseline levels at 12 hours, early release of IL-6 followed by a fall to baseline levels at hours 7 to 9 with a second smaller peak at hours 9 to 11, and isolated early release of IL-6. Early IL-6 production correlated with late histamine production (R = 0.801; p = 0.06), and late IL-6 production correlated with eosinophil influx (R = 0.813; p = 0.05). The area of the LPR at skin test sites correlated with early IL-6 peak levels (R = 0.977; p = 0.004) and with total early IL-6 production (R = 0.885; p = 0.05), but not with late IL-6 production.(ABSTRACT TRUNCATED AT 400 WORDS)
authors.affiliation: Department of Medicine, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Galveston, Texas.
authors.forename: C E
authors.initials: CE
authors.lastname: Lee
authors.forename: M E
authors.initials: ME
authors.lastname: Neuland
authors.forename: H G
authors.initials: HG
authors.lastname: Teaford
authors.forename: B F
authors.initials: BF
authors.lastname: Villacis
authors.forename: P S
authors.initials: PS
authors.lastname: Dixon
authors.forename: S
authors.initials: S
authors.lastname: Valtier
authors.forename: C H
authors.initials: CH
authors.lastname: Yeh
authors.forename: D C
authors.initials: DC
authors.lastname: Fournier
authors.forename: E N
authors.initials: EN
authors.lastname: Charlesworth
mesh_terms: D000485:Allergens / Q000276:immunology*; D001768:Blister / Q000378:metabolism; D001826:Body Fluids / Q000378:metabolism; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007376:Interleukin-2 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D012867:Skin / Q000276:immunology* / Q000378:metabolism
chemical_list: D000485:Allergens; D007376:Interleukin-2; D015850:Interleukin-6