Inflammatory marker analysis of uterine cytobrush samples helps identify mares with endometritis.

Overview

• This study investigated inflammatory markers in uterine samples collected via cytobrush and swab to identify mares suffering from endometritis, a uterine inflammation condition.
• The research found that cytobrush samples provide higher and more reliable inflammatory marker concentrations than swabs and identified specific markers, especially TNF-α and CCL5, that can distinguish healthy mares from those with endometritis.

Background and Purpose

• Endometritis is a common uterine inflammatory condition in mares that can affect reproductive health.
• Diagnosing endometritis accurately is critical for managing breeding and treatment.
• This study aimed to evaluate whether specific inflammatory cytokines and chemokines measured in endometrial samples collected by cytobrush or swab could serve as reliable screening diagnostic markers for detecting equine endometritis.

Methodology

• The study included 88 mares whose endometrial samples were collected by cytobrush, swab, and/or biopsy.
• Collected data incorporated clinical reproductive history, ultrasound evaluations, cytology (cell analysis), cultures, and biopsy grading scores for endometritis diagnosis.
• Using fluorescent bead-based multiplex assays, concentrations of several inflammatory markers were measured: interferon-γ, interferon-α, IL-1β, IL-4, IL-10, IL-17A, soluble CD14, tumor necrosis factor-α (TNF-α), and chemokines CCL2, CCL3, CCL5, and CCL11.
• Samples were analyzed from two groups: reproductively healthy mares and mares diagnosed with endometritis in a prospective cross-sectional design.

Key Findings

• The cytobrush technique yielded higher concentrations of inflammatory markers compared to swab samples, indicating it is a more effective method to detect uterine inflammation.
• Tumor necrosis factor-α (TNF-α) was significantly elevated in cytobrush samples from mares with neutrophils detected on cytology, suggesting active inflammation.
• The median TNF-α concentration in mares with endometritis was 4185 pg/mL, notably higher than the 1718 pg/mL median in mares without endometritis.
• Similarly, a combination of TNF-α (<3942 pg/mL) and CCL5 (<15985 pg/mL) concentrations was highly predictive of a healthy endometrium, achieving 100% accuracy in identifying healthy mares in this study.
• This indicates that measuring these two markers in endometrial cytobrush samples can effectively distinguish healthy mares from those potentially misdiagnosed as healthy by other methods (false negatives).

Implications and Conclusions

• Inflammatory markers, particularly TNF-α and CCL5 in cytobrush samples, serve as effective biomarkers for diagnosing inflammatory endometritis in mares.
• The cytobrush method improves the sensitivity of detecting uterine inflammation compared to swabs, likely due to better sampling of the uterine lining.
• These findings suggest a potential new diagnostic approach that could reduce misdiagnosis of endometritis, allowing for more targeted therapeutic interventions and improved reproductive management in mares.
• Future clinical use of these inflammatory marker measurements may help veterinarians screen for endometritis more reliably and early, even in cases where traditional cytology shows no neutrophils.