Basano Ilaria, Romolo Alessandra, Iamone Giulia, Memoli Giulia, Riccio Barbara, Lavoie Jean-Pierre, Miniscalco Barbara, Bullone Michela
Department of Veterinary Sciences, University of Turin, 10095 Grugliasco, Italy.
Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC J2S 2M2, Canada.
Animals (Basel). 2022 Apr 20;12(9):1070. doi: 10.3390/ani12091070.
Equine asthma is currently diagnosed by the presence of increased neutrophil (>5%), mast cell (>2%), and/or eosinophil (>1%) differential cell count. Macrophages are normal resident cells within the alveoli. Their presence in BALF is considered normal, but the clinical implication of the presence of activated or fused macrophages (giant multinucleated cells, GMC) is currently overlooked. We aimed to assess the prevalence, cytological determinants, and clinical significance of increased GMC counts in BALF of 34 asthmatic horses compared to 10 controls. Counts were performed on 15 randomly selected high magnification fields per cytospin slide (40×), and expressed as GMC:single macrophage (GMC:M) ratio. Regression models were used for statistical analysis. GMC was frequently observed in both asthmatic and control horses, with an increased prevalence of equine asthma (p = 0.01). GMC:M ratio was significantly higher in severe vs. mild to moderate equine asthmatic and control horses. In asthmatic horses, an increased GMC:M ratio was significantly associated with BALF mastocytosis (p = 0.01), once adjusting for age and the presence and severity of clinical signs of the horses. Tachypnea was the only clinical sign that tended to be positively associated with GMC:M ratio after adjustment (p = 0.08). In conclusion, our data suggest that a relationship might exist between molecular mechanisms regulating GMC formation and mast cell recruitment in the equine lung. The same mechanisms could lead to tachypnea even in the absence of respiratory effort at rest. We suggest including GMC count in the basic cytological assessment of BALF samples to gain more insights into their role in equine asthma.
目前，马哮喘的诊断依据是中性粒细胞（>5%）、肥大细胞（>2%）和/或嗜酸性粒细胞（>1%）的分类细胞计数增加。巨噬细胞是肺泡内的正常驻留细胞。它们在支气管肺泡灌洗液（BALF）中的存在被认为是正常的，但目前激活或融合的巨噬细胞（巨大多核细胞，GMC）存在的临床意义被忽视了。我们旨在评估34匹哮喘马与10匹对照马的BALF中GMC计数增加的患病率、细胞学决定因素及临床意义。对每个细胞涂片玻片（40×）随机选择的15个高倍视野进行计数，并表示为GMC:单个巨噬细胞（GMC:M）比值。使用回归模型进行统计分析。在哮喘马和对照马中均经常观察到GMC，马哮喘的患病率增加（p = 0.01）。重度与轻度至中度马哮喘及对照马的GMC:M比值显著更高。在哮喘马中，调整马匹年龄以及临床症状的存在和严重程度后，GMC:M比值增加与BALF肥大细胞增多显著相关（p = 0.01）。调整后，呼吸急促是唯一与GMC:M比值呈正相关趋势的临床症状（p = 0.08）。总之，我们的数据表明，调节马肺中GMC形成和肥大细胞募集的分子机制之间可能存在关联。即使在静息时没有呼吸努力，相同的机制也可能导致呼吸急促。我们建议在BALF样本的基本细胞学评估中纳入GMC计数，以更深入了解它们在马哮喘中的作用。
