Comparison of Tracheal Wash and Bronchoalveolar Lavage Cytology in 154 Horses With and Without Respiratory Signs in a Referral Hospital Over 2009-2015.
Abstract: Most equine lower respiratory diseases present as increased airway neutrophilia, which can be detected in tracheal wash (TW) or bronchoalveolar lavage fluid (BALF) cytology samples. The aim was to compare the TW and BALF results in a population of client-owned horses with and without clinical respiratory disease signs. A secondary aim was to determine the sensitivity (Se) and specificity (Sp) of TW and BALF neutrophilia in detecting respiratory disease. The cutoff values for neutrophils were also evaluated. Retrospective data from 154 horses of various breeds that had been subject to both TW and bronchoalveolar lavage (BAL) sampling at rest during 2009-2015 were used. The horses were divided into three groups based on the presenting signs, physical examination, and endoscopy mucus score. Neutrophil counts of >20% in TW and >5% in BAL were considered abnormal. Cytology results between groups, correlations between TW and BALF cell types, and tracheal mucus score were analyzed. Two graph receiving operating characteristic (ROC) curves of the neutrophil percentage values of TW and BALF were created to determine the optimal cutoff values and to calculate the diagnostic Se and Sp for diagnosing airway inflammation in horses with and without clinical respiratory signs. The Se and Sp of TW and BALF neutrophil percentages were further estimated using a two-test one-population Bayesian latent class model. The two tests showed substantial agreement, and only 17.5% of the horses were classified differently (healthy vs. diseased). The neutrophil percentage was found to correlate between TW and BALF. The Se and Sp of TW were generally higher than for BAL when estimated with area under the curve or Bayesian model. Cutoff values of 17.7% for TW and 7% for BALF were indicated by the ROCs. We conclude that TW is a more sensitive and specific method in our patient population. We suggest that the current neutrophil cutoff values of 20% for TW and 5% for BALF would still be appropriate to use in clinical diagnosis of airway inflammation. However, further studies with other cell types and in other populations are warranted to determine the best sampling method for individual horses.
Publication Date: 2018-03-26 PubMed ID: 29632867PubMed Central: PMC5879091DOI: 10.3389/fvets.2018.00061Google Scholar: Lookup
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- Journal Article
- Bayesian Analysis
- Bronchoalveolar Lavage
- Clinical Examination
- Clinical Pathology
- Clinical Signs
- Correlation Analysis
- Cytology
- Diagnostic Technique
- Disease Diagnosis
- Disease Treatment
- Equine Health
- Horses
- Neutrophils
- Respiratory Disease
- Retrospective Study
- Trachea
- Veterinary Practice
- Veterinary Research
- White Blood Cells
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This study focuses on comparing the effectiveness of tracheal wash (TW) and bronchoalveolar lavage fluid (BALF) cytology in detecting respiratory diseases in horses. It revealed that TW is generally more specific and sensitive.
Objectives of the Study
- The main aim of the research was to compare TW and BALF cytology data in a group of horses showing respiratory disease symptoms to those without.
- The secondary aim was to ascertain the specificity and sensitivity of TW and BALF neutrophilia in identifying respiratory diseases in horses. The study also aimed at determining the cutoff values for neutrophils.
Methodology
- Retrospective data from 154 horses of different breeds, sampled between 2009 and 2015 while at rest, were used.
- The horses were classified into three groups based on the observed signs, physical examination results, and endoscopy mucus score, with neutrophil counts over 20% in TW and above 5% in BAL considered as abnormal.
- The researchers analyzed the cytology results between these groupings, studied the correlation between various cell types in TW and BALF and tracheal mucus score.
- To establish optimal cutoff values, and to compute the diagnostic specificity and sensitivity of diagnosing airway inflammation in horses exhibiting respiratory signs, two graph receiving operating characteristic (ROC) curves of the neutrophil percentage values of TW and BALF were created.
- The specificity and sensitivity of TW and BALF neutrophil percentages were further estimated using a two-test one-population Bayesian latent class model.
Findings of the Study
- The two methods showed substantial agreement, with only 17.5% of the horses classified differently (healthy vs. diseased).
- A connection was deduced between the percentage of neutrophils in TW and BALF.
- Generally, TW had a higher sensitivity and specificity than BALF, as estimated with the curve area or Bayesian model.
- ROCs proposed cutoff values of 17.7% for TW and 7% for BALF.
Conclusions
- Based on the findings, the researchers concluded that TW is a more sensitive and specific technique in diagnosing respiratory diseases in their study population.
- The currently employed neutrophil cutoff values of 20% for TW and 5% for BALF were still seen as appropriate for airway inflammation clinical diagnosis.
- The researchers suggest the need for additional research involving different populations and cell types to determine the most effective method of sampling for individual horses.
Cite This Article
APA
Rossi H, Virtala AM, Raekallio M, Rahkonen E, Rajamäki MM, Mykkänen A.
(2018).
Comparison of Tracheal Wash and Bronchoalveolar Lavage Cytology in 154 Horses With and Without Respiratory Signs in a Referral Hospital Over 2009-2015.
Front Vet Sci, 5, 61.
https://doi.org/10.3389/fvets.2018.00061 Publication
Researcher Affiliations
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
- Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
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