Nishiike Masao, Haoka Michiyo, Doi Takashi, Kohda Tomoko, Mukamoto Masafumi
Department of Veterinary Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku Orai-Kita, Izumisano, Osaka 599-8531, Japan.
J Vet Med Sci. 2016 Aug 1;78(7):1145-51. doi: 10.1292/jvms.16-0022. Epub 2016 Apr 8.
Analysis of the association between antibodies against bovine leukemia virus (BLV), BLV proviral load, and white blood cell (WBC) and lymphocyte counts was performed with 774 dairy cows. The average age, WBC counts and lymphoid cell counts tended to be higher in BLV antibody-positive cows than in antibody-negative cows. There was a similar trend in levels of proviral DNA. We analyzed age, WBC counts and lymphocyte counts by principal component analyses to create a distribution chart of the principle component scores. Using the chart, we categorized cows into four quadrants based on additional information, such as the presence of antibody and the levels of proviral DNA. Antibody-positive cows and cows with high BLV proviral load were found mostly in one quadrant of the chart, indicating that it is possible to predict the risk of infection without any knowledge on antibody status by using information, such as WBC counts as a biomarker. When only antibody-positive cows were included in the analysis, a characteristic distribution of different levels of proviral DNA was seen in the quadrants, suggesting that it is possible to estimate the extent of bovine leukosis infection by using this analysis. For this analysis and categorization of the cows into quadrants, we computed a mathematical formulation using discriminant analysis based on age and WBC and lymphocyte counts. This mathematical formulation for the hematological preliminary diagnosis of the disease is recommended as a screening tool to monitor bovine leukosis.
对774头奶牛进行了抗牛白血病病毒（BLV）抗体、BLV前病毒载量与白细胞（WBC）及淋巴细胞计数之间相关性的分析。BLV抗体阳性奶牛的平均年龄、WBC计数和淋巴细胞计数往往高于抗体阴性奶牛。前病毒DNA水平也有类似趋势。我们通过主成分分析对年龄、WBC计数和淋巴细胞计数进行分析，以创建主成分得分分布图。利用该图，我们根据抗体存在情况和前病毒DNA水平等附加信息将奶牛分为四个象限。抗体阳性奶牛和BLV前病毒载量高的奶牛大多位于图中的一个象限，这表明通过使用诸如WBC计数作为生物标志物等信息，在不了解抗体状态的情况下也有可能预测感染风险。当分析仅包括抗体阳性奶牛时，在象限中可见不同水平前病毒DNA的特征性分布，这表明通过这种分析有可能估计牛白血病感染的程度。为了进行这种分析并将奶牛分类到象限中，我们基于年龄、WBC和淋巴细胞计数使用判别分析计算了一个数学公式。推荐将这种用于该疾病血液学初步诊断的数学公式作为监测牛白血病的筛查工具。
