Swenson Cheryl L, Erskine Ronald J, Bartlett Paul C
Department of Pathobiology and Diagnostic Investigation and Diagnostic Center for Population and Animal Health, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
J Am Vet Med Assoc. 2013 Jul 1;243(1):131-5. doi: 10.2460/javma.243.1.131.
To determine the effect of bovine leukemia virus (BLV) infection on absolute neutrophil and lymphocyte concentrations in healthy lactating Holstein dairy cattle.
Observational cross-sectional survey.
311 healthy lactating Holstein dairy cattle from herds in Michigan (n = 2), Wisconsin (1), Iowa (1), and Pennsylvania (1).
Whole and anticoagulated (EDTA) blood samples were collected. Serum samples were tested for antibody against BLV by use of an ELISA. Absolute neutrophil and lymphocyte concentrations were measured in EDTA blood samples with an automated hematology analyzer and manual differential cell counts.
208 cows tested positive and 103 cows tested negative for anti-BLV antibodies. Neutrophil concentration was not significantly different between BLV-positive versus BLV-negative cattle. The distribution of lymphocyte concentration was positively skewed for the entire cow population (n = 311) and the BLV-positive subset (208). In contrast, lymphocyte concentration distribution was approximately normal for BLV-negative cows (n = 103). Consequently, the presence or absence of BLV infection strongly influenced the calculated neutrophil-to-lymphocyte concentration ratio.
Results indicated that absolute lymphocyte concentration is significantly affected by BLV infection in dairy cattle. Accordingly, hematologic reference intervals should be derived from healthy animals that are not infected with BLV and patient BLV status must be considered for meaningful interpretation of lymphocyte concentration. We recommend that the calculated neutrophil-to-lymphocyte ratio be abandoned because it does not provide more information than direct comparison of patient absolute leukocyte concentration with updated reference intervals from healthy BLV-negative cattle.
确定牛白血病病毒（BLV）感染对健康泌乳荷斯坦奶牛绝对中性粒细胞和淋巴细胞浓度的影响。
观察性横断面调查。
来自密歇根州（n = 2）、威斯康星州（1）、爱荷华州（1）和宾夕法尼亚州（1）牛群的311头健康泌乳荷斯坦奶牛。
采集全血和抗凝（乙二胺四乙酸）血样。使用酶联免疫吸附测定法检测血清样本中抗BLV抗体。使用自动血液分析仪和手工细胞分类计数法测量乙二胺四乙酸血样中的绝对中性粒细胞和淋巴细胞浓度。
208头奶牛抗BLV抗体检测呈阳性，103头奶牛检测呈阴性。BLV阳性牛与BLV阴性牛的中性粒细胞浓度无显著差异。整个奶牛群体（n = 311）和BLV阳性亚组（208头）的淋巴细胞浓度分布呈正偏态。相比之下，BLV阴性奶牛（n = 103）的淋巴细胞浓度分布近似正态。因此，BLV感染的存在与否强烈影响计算得出的中性粒细胞与淋巴细胞浓度比值。
结果表明，BLV感染对奶牛的绝对淋巴细胞浓度有显著影响。因此，血液学参考区间应来源于未感染BLV的健康动物，并且为了对淋巴细胞浓度进行有意义的解读，必须考虑患畜的BLV状态。我们建议放弃计算中性粒细胞与淋巴细胞比值，因为与将患畜绝对白细胞浓度与来自健康BLV阴性奶牛的更新参考区间直接比较相比，它并未提供更多信息。
