Lection J, Wagner B, Byron M, Miller A, Rollins A, Chenier T, Cheong SH, Diel de Amorim M. Inflammatory markers for differentiation of endometritis in the mare.
Equine Vet J 2024;
56:678-687. [PMID:
38219734 DOI:
10.1111/evj.14058]
[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: 01/18/2023] [Accepted: 12/14/2023] [Indexed: 01/16/2024]
Abstract
BACKGROUND
Endometrial biopsy is required to diagnose mares with chronic endometritis and endometrial degenerative fibrosis. An increase in understanding of equine reproductive immunology could be utilised to create less-invasive, time-efficient diagnostic tools especially when evaluating mares for chronic endometritis.
OBJECTIVES
To evaluate inflammatory cytokine and chemokine concentrations in uterine fluid samples collected by low-volume lavage (LVL) as a potential screening diagnostic biomarker for endometritis.
STUDY DESIGN
Prospective cross-sectional clinical study.
METHODS
Forty-six mares underwent a LVL and subsequently endometrial biopsy. Mares were split in three groups: healthy, acute endometritis, and chronic endometrial fibrosis (CEF) based on cytological and histological evaluation. A fluorescent bead-based multiplex assay for IFN-γ, IFN-α, IL-1β, IL-4, IL-10, IL-17, sCD14, TNF-α, CCL2, CCL3, CCL5 and CCL11 were carried out on the LVL fluid. The endometrial biopsy was utilised for histology and qPCR of IFN-γ, IL-1β, IL-6, IL-8, IL-17, TNF-α, CCL2 and CCL3 genes. Statistical analyses examined differences in inflammatory markers and predictive modelling for diseased endometrium.
RESULTS
Secreted concentrations of IFN-γ were lower in LVL fluid from reproductively healthy mares compared with acute endometritis (p = 0.04) and CEF (p = 0.006). Additionally, IL-17, IL-10, IL-1β, TNF-α, CCL2, CCL3, CCL5 and CCL11 were significantly increased (p ≤ 0.04) in LVL from CEF mares compared with healthy mares. Mares with CCL2 concentrations ≥550 pg/mL (14/14) had 100% probability of having CEF and/or acute endometritis. Healthy mares had lower relative abundance of IL-17 mRNA compared with mares in CEF group [median (interquartile rage) = 14.76 (13.3, 15.3) and 12.4 (10.54, 13.81)], respectively (p = 0.02).
MAIN LIMITATIONS
Limited sample size: larger numbers of mares with and without endometritis are required and reference intervals in LVL samples have to be established.
CONCLUSIONS
Inflammatory chemokines and cytokines concentrations differed between healthy mares and mares with acute endometritis or CEF in LVL.
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