Detection of neutralizing antibodies in postweaning multisystemic wasting syndrome (PMWS)-affected and non-PMWS-affected pigs
Detection of neutralizing antibodies in postweaning multisystemic wasting syndrome (PMWS)-affected and non-PMWS-affected pigs
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DOI：
10.1016/j.vetmic.2007.06.004
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发表时间：
2007-12-15
影响因子：
3.3
通讯作者：
Mateu, Enric
中科院分区：
文献类型：
--
作者：
Fort, Maria;Olvera, Alex;Mateu, Enric
在一些研究中已经报道了受产后多系统衰竭综合征（PMWS）影响的猪对猪圆环病毒2型（PCV 2）的体液反应受损的概念。然而，关于PCV 2感染猪中中和抗体（NA）的存在及其在疾病发病机制中的作用的信息很少。本工作的目的是进一步表征不同PCV 2感染状态的猪的体液反应，特别是NA的产生。根据PCV 2感染和临床病理状态将来自不同猪场的72头常规猪分为3组，即：PCV 2阴性、非PMWS PCV 2阳性和PMWS感染动物。此外，还研究了来自实验感染的9周龄猪（6头对照猪和14头PCV 2接种猪）。测定猪血清中的NA和总PCV 2抗体（TA）以及病毒载量，并与猪的临床病理状态进行相关性分析。结果表明，受PMWS影响的猪的NA滴度（如果有的话）低于健康动物。NA fitres也与血清中的PCV 2载量呈负相关。NA和TA滴度呈正相关;然而，感染状态之间的相关性不同，PCV 2阳性猪的相关性较低。此外，评价了每种检测的诊断性能，表明血清中病毒中和和定量PCR的组合可用于丢弃PMWS（特异性92%）。在实验感染的动物中，NA的演变与TA的过程一致，尽管在一些动物中观察到NA产生的轻微延迟。NA的增加与病毒载量的下降一致。这项工作的结果进一步支持PMWS感染的猪显示出受损的体液免疫应答，特别是针对PCV 2的无效NA应答。
The notion that postwearring multisystemic wasting syndrome (PMWS)-affected pigs develop an impaired humoral response against porcine circovirus type 2 (PCV2) has been reported in several studies. However, little information is available regarding the presence of neutralizing antibodies (NA) in PCV2-infected pigs and their role in the pathogenesis of the disease. The aim of the present work was to further characterize the humoral response, and in particular the production of NA, in pigs with different PCV2-infection status. Seventy-two conventional pigs from different farms were classified into three groups based on PCV2 infection and clinico-pathological status, namely: PCV2-negative, non-PMWS PCV2-positive and PMWS-affected animals. In addition, 9-week old pigs from an experimental infection (6 controls and 14 PCV2-inoculated pigs) were also studied. NA and total PCV2 antibodies (TA) as well as viral load in serum were determined and correlated with the clinico-pathological status of pigs. Results indicated that PMWS-affected pigs had lower NA titres, if any, than healthy animals. NA fitres were also inversely correlated with PCV2 load in serum. NA and TA titres were positively correlated; however, correlation differed among infection status, being lower in PCV2-positive pigs. Also, the diagnostic performance of each test was evaluated, indicating that the combination of viral neutralization and quantitative PCR in serum was useful to discard PMWS (specificity 92%). In experimentally infected animals, the evolution of NA paralleled the course TA, although a slight delay in NA production was seen in some animals. The increase of NA coincided with the drop in viral load. Results from this work further support that PMWS-affected pigs show an impaired humoral immune response and, particularly, an inefficient NA response against PCV2.