Hematologic and immunophenotypic factors associated with development of Rhodococcus equi pneumonia of foals at equine breeding farms with endemic infection
Hematologic and immunophenotypic factors associated with development of Rhodococcus equi pneumonia of foals at equine breeding farms with endemic infection
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DOI：
10.1016/j.vetimm.2004.02.010
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发表时间：
2004-07-01
影响因子：
1.8
通讯作者：
Smith, R
中科院分区：
文献类型：
--
作者：
Chaffin, MK;Cohen, ND;Smith, R
马红球菌会导致马驹和免疫功能低下的人患上严重的化脓性肉芽肿性肺炎。在小鼠中，CD4+ 和 CD8+ T 淋巴细胞都有助于宿主防御马罗氏菌，但肺部清除细菌需要 CD4+ T 淋巴细胞。在这项前瞻性研究中，我们对两个患有地方性马股沟菌感染的马养殖场的 208 匹马驹进行了前瞻性研究，我们收集了 2 周龄和 4 周龄以及诊断马股沟菌肺炎时的外周血样本。分析样品中总白细胞和分类白细胞、EqCD4+ 和 EqCD8+ T 淋巴细胞以及 B 淋巴细胞的浓度。三十匹（14.4%）小马驹患上马立克体肺炎。在出生后第 2 周，受影响马驹的白细胞 (WBC) 和分段中性粒细胞浓度显着降低，EqCD4+ T 淋巴细胞比例显着降低，EqCD8+ T 淋巴细胞比例显着升高。受影响马驹的 EqCD4:EqCD8 比率显着较低。在出生后第 4 周，受影响的马驹的分段中性粒细胞和 EqCD4+ T 淋巴细胞浓度显着低于未受影响的马驹。受影响马驹的 EqCD4:EqCD8 比率显着降低。 EqCD4:EqCD8 比率 < 3 的 2 周龄和 4 周龄马驹明显更容易患马股癣菌肺炎。存在显着的农场效应，削弱了我们发现差异的统计能力；然而;调整农场效应后，EqCD4:EqCD8 比率 < 3 的 2 周龄小马驹仍明显更容易患马立克体肺炎。受影响的马驹（诊断时）和年龄匹配的对照马驹之间的免疫表型变量没有显着差异。这些数据表明，在马驹肺炎临床症状出现之前的前 2-4 周内，受影响和未受影响的马驹之间存在血液学和免疫表型差异。这些差异可能代表了与个体马驹对马冠病毒感染的易感性增加相关的重要免疫机制。由于受影响和未受影响的马驹的值之间存在相当大的重叠，因此我们尚不能推荐对地方性感染农场的马驹进行免疫表型分析，作为一种临床上有用的筛查工具来识别马驹患马股癣肺炎的风险增加。 (C) 2004 年由 Elsevier B.V. 出版
Rhodococcus equi causes severe pyogranulomatous pneumonia in foals and in immunocompromised people. In mice, both CD4+ and CD8+ T lymphocytes contribute to host defense against R. equi, but CD4+ T lymphocytes are required for pulmonary clearance of the bacteria. In this prospective study of 208 foals at two equine breeding farms with endemic R. equi infections, we collected peripheral blood samples at 2 and 4 weeks of age and at the time of diagnosis of R. equi pneumonia. Samples were analyzed for concentrations of total and differential leukocytes, EqCD4+ and EqCD8+ T lymphocytes, and B lymphocytes. Thirty (14.4%) foals developed R. equi pneumonia. At the 2nd week of life, affected foals had significantly lower concentrations of white blood cells (WBC) and segmented neutrophils, significantly lower proportions of EqCD4+ T lymphocytes, and significantly higher proportions of EqCD8+ T lymphocytes. The EqCD4:EqCD8 ratio was significantly lower for affected foals. At the 4th week of life, affected foals had significantly lower concentrations of segmented neutrophils and EqCD4+ T lymphocytes than did unaffected foals. The ratio of EqCD4:EqCD8 was significantly lower for affected foals. Two- and 4-week-old foals with ratios of EqCD4:EqCD8 < 3 were significantly more likely to develop R. equi pneumonia. There was a significant farm effect which diluted our statistical power to detect differences; however; after adjusting for the farm effect, 2-week-old foals with ratios of EqCD4:EqCD8 < 3 remained significantly more likely to develop R. equi pneumonia. There were no significant differences in immunophenotypic variables between affected foals (at the time of diagnosis) and age-matched control foals. These data suggest that there are hematologic and immunophenotypic differences between affected and unaffected foals during the first 2-4 weeks of life, prior to onset of clinical signs of R. equi pneumonia. These differences may represent important immunologic mechanisms associated with increased susceptibility of individual foals to infection with R. equi. Because there was considerable overlap between values for affected and unaffected foals, we cannot yet recommend immunophenotyping of foals at endemically-infected farms as a clinically useful screening tool to identify foals at increased risk of developing R. equi pneumonia. (C) 2004 Published by Elsevier B.V.