Jocelyn N A, Wylie C E, Lean M, Barrelet A, Foote A K
Department of Clinical Sciences and Services, Royal Veterinary College, London, UK.
Rossdales Laboratories, Rossdales LLP, Newmarket, Suffolk, UK.
Equine Vet J. 2018 Nov;50(6):752-758. doi: 10.1111/evj.12837. Epub 2018 Apr 17.
Tracheal wash sample neutrophilia is common in lower airway inflammation of various causes; however, relevance of cytomorphological features to culture of bacterial pathogens has not been established.
To investigate whether the presence of nondegenerate or degenerate neutrophils in tracheal washes is associated with culture of bacteria and, if so, whether this is influenced by age or temporal factors.
Cross-sectional study.
Tracheal wash samples submitted to Rossdales LLP from 1/1/2013 to 31/7/2015 were evaluated using set criteria. Neutrophilia and degenerate neutrophilia (graded ≥2/4 on Rossdales cytological scale [0-4]) were analysed in relation to bacterial isolates considered potentially pathogenic in respiratory disease. Statistical analyses included multivariable logistic regression to identify associations between two separate outcomes: 1) the presence of neutrophilia compared with no neutrophilia and 2) the presence of degenerate neutrophilia compared with nondegenerate neutrophilia and four independent variables.
Sufficient data for inclusion in the multivariable model for nondegenerate neutrophilia were available from 1100 horses. Culture of potentially pathogenic bacteria was associated with increased odds of degenerate neutrophilia compared with samples with negative culture (OR 4.5, 95% CI 3.1, 6.4, P-value<0.001). Horses over 9 years old had lower odds of having degenerate neutrophilia than those aged 1-3 years (OR 0.6, 95% CI 0.4, 0.9, P-value<0.02). In the spring/summer, horses had reduced odds of a degenerate neutrophilia compared with winter (OR 0.4, 95% CI 0.3, 0.7, P-value <0.001).
The study relied on routine laboratory submissions, with no control over sample collection or submitted clinical history.
Cytological evaluation of tracheal washes should include cytomorphological features of the neutrophil response. The presence of degenerate neutrophils, especially in young horses, indicates added value of culture and sensitivity for antimicrobial therapeutics. The absence of degenerate changes, in combination with clinical factors, can help support diagnosis of a nonseptic cause of airway neutrophilia.
气管冲洗样本中的中性粒细胞增多在各种原因引起的下呼吸道炎症中很常见；然而，细胞形态学特征与细菌病原体培养之间的相关性尚未确立。
研究气管冲洗液中未退化或退化的中性粒细胞的存在是否与细菌培养有关，如果有关，年龄或时间因素是否会对此产生影响。
横断面研究。
对2013年1月1日至2015年7月31日提交给罗斯代尔斯有限责任公司的气管冲洗样本按照既定标准进行评估。分析中性粒细胞增多和退化性中性粒细胞增多（在罗斯代尔斯细胞学量表[0-4]上分级≥2/4）与呼吸道疾病中被认为具有潜在致病性的细菌分离株的关系。统计分析包括多变量逻辑回归，以确定两个单独结果之间的关联：1）中性粒细胞增多与无中性粒细胞增多的情况；2）退化性中性粒细胞增多与未退化性中性粒细胞增多以及四个独立变量的情况。
从1100匹马中获得了足够的数据纳入未退化性中性粒细胞增多的多变量模型。与培养阴性的样本相比，潜在致病细菌的培养与退化性中性粒细胞增多的几率增加有关（比值比4.5，95%置信区间3.1，6.4，P值<0.001）。9岁以上的马出现退化性中性粒细胞增多的几率低于1-3岁的马（比值比0.6，95%置信区间0. , P值<0.02）。在春季/夏季，与冬季相比，马出现退化性中性粒细胞增多的几率降低（比值比0.4，95%置信区间0.3，0.7，P值<0.001）。
该研究依赖于常规实验室送检，对样本采集或提交的临床病史没有控制。
气管冲洗液的细胞学评估应包括中性粒细胞反应的细胞形态学特征。退化性中性粒细胞的存在，尤其是在幼马中，表明培养和抗菌治疗敏感性的附加价值。未退化性变化的不存在与临床因素相结合，有助于支持对气道中性粒细胞增多的非感染性原因的诊断。
