Bond S, Léguillette R. A CONSORT-guided, randomized controlled clinical trial of nebulized administration of dexamethasone and saline on lower airway cytokine mRNA expression in horses with moderate asthma.
J Vet Intern Med 2024;
38:1214-1223. [PMID:
38205666 PMCID:
PMC10937472 DOI:
10.1111/jvim.16983]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND
Nebulized administration of dexamethasone on cytokine regulation in horses with moderate asthma has not been investigated.
OBJECTIVE
To investigate the changes in expression of inflammatory cytokine mRNA after nebulized administration of dexamethasone treatment of horses with moderate asthma.
ANIMALS
Horses with naturally occurring moderate asthma (n = 16) and healthy control horses (n = 4). All horses were kept in a dusty environment during the study.
METHODS
Prospective, parallel, randomized, controlled, blinded clinical trial. Blood endogenous cortisol, tracheal mucus, and bronchoalveolar lavage (BAL) were sampled before and after 13 days treatment with either nebulized administration of dexamethasone (15 mg once daily) or 0.9% saline (3 mL). Treatment groups were randomly allocated via randomization function (Microsoft Excel). Amplification of target mRNA in BAL fluid (IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-17, IL-23, IFN-γ, Eotaxin-2, and TNF-α) was achieved by qPCR, and the relative expression software tool was used to analyze BAL inflammatory cytokine mRNA.
RESULTS
Horses treated with nebulized administration of dexamethasone had increased relative expression of IL-5 (1.70-fold), IL-6 (1.71-fold), IL-17 (3.25-fold), IL-12 (1.66-fold), and TNF-α (1.94-fold), and decreased relative expression of IL-23 (1.76-fold; P = .04) in samples collected on Day 14, in comparison to samples collected on Day 0 (all P < .05). Horses treated with nebulized administration of saline had no significant difference in the relative expression of any gene (all P > .05).
CONCLUSIONS AND CLINICAL IMPORTANCE
Nebulized administration of dexamethasone was associated with increased expression of inflammatory cytokine mRNA. There was no improvement in inflammatory airway cytology associated with either dexamethasone or saline treatment.
Collapse