Dunbar Dawn, Kwok Wendy, Graham Elizabeth, Armitage Andy, Irvine Richard, Johnston Pamela, McDonald Michael, Montgomery Dorothy, Nicolson Lesley, Robertson Elise, Weir William, Addie Diane D
Veterinary Diagnostic Services, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
Department of Infectious Diseases and Public Health, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong.
J Feline Med Surg. 2019 Oct;21(10):910-921. doi: 10.1177/1098612X18809165. Epub 2018 Nov 8.
The aim of this study was to evaluate a feline coronavirus (FCoV) reverse transcriptase quantitative PCR (RT-qPCR) on fine-needle aspirates (FNAs) from mesenteric lymph nodes (MLNs) collected in sterile saline for the purpose of diagnosing non-effusive feline infectious peritonitis (FIP) in cats.
First, the ability of the assay to detect viral RNA in MLN FNA preparations compared with MLN biopsy preparations was assessed in matched samples from eight cats. Second, a panel of MLN FNA samples was collected from a series of cats representing non-effusive FIP cases (n = 20), FCoV-seropositive individuals (n = 8) and FCoV-seronegative individuals (n = 18). Disease status of the animals was determined using a combination of gross pathology, histopathology and/or 'FIP profile', consisting of serology, clinical pathology and clinical signs.
Viral RNA was detected in 18/20 non-effusive FIP cases; it was not detected in two cases that presented with neurological FIP. Samples from 18 seronegative non-FIP control cats and 7/8 samples from seropositive non-FIP control cats contained no detectable viral RNA. Thus, as a method for diagnosing non-effusive FIP, MLN FNA RT-qPCR had an overall sensitivity of 90.0% and specificity of 96.1%.
In cases with a high index of suspicion of disease, RT-qPCR targeting FCoV in MLN FNA can provide important information to support the ante-mortem diagnosis of non-effusive FIP. Importantly, viral RNA can be reliably detected in MLN FNA samples in saline submitted via the national mail service. When applied in combination with biochemistry, haematology and serological tests in cases with a high index of suspicion of disease, the results of this assay may be used to support a diagnosis of non-effusive FIP.
本研究旨在评估一种用于猫肠系膜淋巴结（MLN）细针穿刺抽吸物（FNA）的猫冠状病毒（FCoV）逆转录定量聚合酶链反应（RT-qPCR），这些FNA是在无菌盐水中收集的，用于诊断猫的非渗出性猫传染性腹膜炎（FIP）。
首先，在来自8只猫的配对样本中，评估该检测方法与MLN活检样本相比，在MLN FNA样本中检测病毒RNA的能力。其次，从一系列猫中收集一组MLN FNA样本，这些猫代表非渗出性FIP病例（n = 20）、FCoV血清阳性个体（n = 8）和FCoV血清阴性个体（n = 18）。通过大体病理学、组织病理学和/或“FIP概况”（包括血清学、临床病理学和临床症状）相结合的方法确定动物的疾病状态。
在20例非渗出性FIP病例中有18例检测到病毒RNA；2例出现神经型FIP的病例未检测到病毒RNA。18只血清阴性的非FIP对照猫的样本以及8只血清阳性的非FIP对照猫中的7/8样本均未检测到可检测的病毒RNA。因此，作为诊断非渗出性FIP的方法，MLN FNA RT-qPCR的总体敏感性为90.0%，特异性为96.1%。
在高度怀疑患病的病例中，针对MLN FNA中的FCoV进行RT-qPCR可为非渗出性FIP的生前诊断提供重要信息。重要的是，通过国家邮政服务提交的盐水中的MLN FNA样本中可以可靠地检测到病毒RNA。当在高度怀疑患病的病例中与生物化学、血液学和血清学检测联合应用时，该检测结果可用于支持非渗出性FIP的诊断。
