title: Reversal of methylprednisolone effects in allergen-exposed female BALB/c mice.
abstract: A high percentage of asthma is associated with aeroallergen exposures. Glucocorticoids such as methylprednisolone represent a major method for managing chronic asthma. However, studies suggested that corticosteroid therapy might have the potential to stimulate rather than inhibit adaptive immune inflammatory reactions, raising concerns about possible adverse reactions due to excessive repeated methylprednisolone treatment. Therefore, a murine model of allergen-induced inflammation was characterized and used to investigate the effects of repeated intraperitoneal (ip) and transnasal treatments with methylprednisolone (0-20 mg/kg body weight) and cyclosporin A (20 mg/kg body weight). Sensitized BALB/c female mice were exposed daily to ovalbumin (OVA) aerosols for up to 5 d with 24-h postexposure analyses for airway responses to methacholine aerosols and inflammatory cell recoveries by bronchoalveolar lavage (BAL) and tissue collagenase dispersion. Although increased tissue neutrophils, lymphocytes, monocytes, and macrophages reached maximal levels after 2 daily OVA exposures, recoverable eosinophil numbers continued to rise over the 5-d period. Daily ip treatments with a 5-mg/kg body weight dose of methylprednisolone diminished both OVA-induced airway responses to methacholine and inflammatory-cell accumulations to levels comparable to those observed with cyclosporin A. However, treatments with higher doses of methylprednisolone reversed this anti-inflammatory effect, indicated by a return to untreated levels of OVA-induced eosinophil recovery. A similar biphasic response in eosinophil recoveries was observed using daily transnasal methylprednisolone treatments that correlated with a concomitant fall and rise in BAL interleukin-13. These results supported the hypothesis that repeated high-steroid treatments might activate rather than suppress allergen-induced immune responses.
authors.affiliation: Department of Family Medicine & Public Health Sciences, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA. dbassett@med.wayne.edu
authors.forename: David
authors.initials: D
authors.lastname: Bassett
authors.forename: Fusao
authors.initials: F
authors.lastname: Hirata
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Gao
authors.forename: Rangaramanujam
authors.initials: R
authors.lastname: Kannan
authors.forename: Janet
authors.initials: J
authors.lastname: Kerr
authors.forename: Nicole
authors.initials: N
authors.lastname: Doyon-Reale
authors.forename: Susan
authors.initials: S
authors.lastname: Wilson
authors.forename: Mary
authors.initials: M
authors.lastname: Lieh-Lai
mesh_terms: D000281:Administration, Intranasal; D000485:Allergens; D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D016572:Cyclosporine / Q000494:pharmacology; D004195:Disease Models, Animal; D004336:Drug Antagonism; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D008168:Lung / Q000187:drug effects* / Q000276:immunology / Q000503:physiopathology; D016210:Methacholine Chloride; D008775:Methylprednisolone / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin; D012129:Respiratory Function Tests; D012130:Respiratory Hypersensitivity / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology
chemical_list: D000485:Allergens; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D016210:Methacholine Chloride; D016572:Cyclosporine; D010047:Ovalbumin; D008775:Methylprednisolone