The objective of this study was to investigate the associations between natural antibodies (NAbs) and total serum immunoglobulins (Igs) concentrations (both from IgG and IgM isotypes), with variables of polymorphonuclear leukocytes (PMN) function of dairy cows in the early postpartum period. Seventy-five healthy postpartum dairy cows at 2 ± 1 days in milk were enrolled in a cross-sectional study. Natural and total antibodies in serum samples were measured by ELISA. Flow cytometry was used to determine the phagocytosis and oxidative burst capacities of PMN and the quantification of the adhesion molecule l-selectin. Leukocyte count and differentials, and serum haptoglobin were also measured. A positive correlation between NAbsIgM and total serum IgM and between NAbsIgM and NAbsIgG were found. Before performing the associations between circulating Igs concentrations and PMN function variables, cows were categorized into having low, medium or high circulating antibodies based on their NAbs and total Igs serum concentrations. None of the PMN variables assessed differed between low, medium, and high cows for both NAbsIgM and NAbsIgG. While associations between PMNs function and total IgG were not observed, some associations between total IgM concentrations and PMN activity were found. Cows with high serum IgM had greater phagocytic activity compared to cows in the low IgM group. Finally, the proportion of PMN that performed oxidative burst and PMN surface expression of l-selectin intensity was greater in high total IgM group when compared to medium and low groups. In conclusion, association between NAbs, and PMN activity variables were not observed, but total serum IgM was associated to some PMN function variables in early post-partum dairy cows.

中文翻译：

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产后早期奶牛自然抗体循环水平，血清总免疫球蛋白和多形核白细胞功能之间的关联。

这项研究的目的是调查天然抗体（NAbs）与血清总免疫球蛋白（Igs）浓度（来自IgG和IgM同种型）之间的关联，以及产后早期奶牛的多形核白细胞（PMN）功能变量。在横断面研究中纳入了75头健康的产后2±1天产奶牛。通过ELISA测量血清样品中的天然和总抗体。流式细胞仪用于确定PMN的吞噬作用和氧化爆发能力以及粘附分子1-选择素的定量。还测量了白细胞计数和差异，以及血清触珠蛋白。发现NAbsIgM与总血清IgM之间以及NAbsIgM与NAbsIgG之间呈正相关。在进行循环Igs浓度与PMN功能变量之间的关联之前，根据奶牛的NAb和总Igs血清浓度将其分为低，中或高循环抗体。在低，中和高奶牛中，NAbsIgM和NAbsIgG的PMN变量均无差异。虽然未观察到PMN功能与总IgG之间的关联，但发现总IgM浓度与PMN活性之间存在某些关联。与低IgM组相比，血清IgM高的母牛具有更高的吞噬活性。最后，与中低组相比，高总IgM组中发生氧化爆发的PMN比例和1-选择素强度的PMN表面表达更大。总之，NAb之间的关联