Oliveira Edward, Saliba Juliana Wilke, Oliveira Diana, Dias Edelberto Santos, Paz Gustavo Fontes
Clinical Research Laboratory, Centro de Pesquisas René Rachou-FIOCRUZ, Av. Augusto de Lima, 1715, 30190-002, Belo Horizonte, Minas Gerais State, Brazil.
Clinical Research Laboratory, Centro de Pesquisas René Rachou-FIOCRUZ, Av. Augusto de Lima, 1715, 30190-002, Belo Horizonte, Minas Gerais State, Brazil.
Vet Parasitol. 2016 May 15;221:9-13. doi: 10.1016/j.vetpar.2016.02.006. Epub 2016 Feb 6.
This report describes the stege I/II development of a new direct agglutination test (DAT) for the diagnosis of canine visceral leishmaniasis (CVL) using freeze-dried antigen produced Coomassie blue-stained Leishmania (Leishmania) infantum promastigotes. In stage I, 16 canine serum samples, collected from eight dogs carrying CVL and eight healthy dogs, were assessed with the DAT using 2-mercaptoethanol (2-ME), N-acetyl-cysteine (NAC), kaolin or NAC plus urea (NAC+U) to improve the assay conditions. Stage II assessed the diagnostic accuracy with 100 serum samples collected from dogs with symptomatic CVL and clinically healthy dogs, comparing the four different sample diluents. The CVL-DAT prototype kit showed equivalent performances when 2-ME, NAC or NAC+U were used: 97.1% sensitivity (CI: 83-99.8%), 97% specificity (CI: 88.5-99.5%) and a 97% diagnostic accuracy (CI: 90.8-99.2). With kaolin, a 94.1% sensitivity (CI: 79-99%), 97% specificity (CI: 88.5-99.5%) and 96% diagnostic accuracy were observed (CI: 89.5-98.7), with no statistically significant differences among the four reagents (p=1.0). The NAC plus urea in sample diluent decreased non-specific agglutination, promoted a better defined sharp-edged blue spot and was thus chosen as a component for the new DAT prototype to diagnose canine VL, designated DAT-Canis.
本报告描述了一种用于诊断犬内脏利什曼病（CVL）的新型直接凝集试验（DAT）的I/II期开发情况，该试验使用考马斯亮蓝染色的婴儿利什曼原虫前鞭毛体冻干抗原。在I期，使用2-巯基乙醇（2-ME）、N-乙酰半胱氨酸（NAC）、高岭土或NAC加尿素（NAC+U）对从8只携带CVL的犬和8只健康犬采集的16份犬血清样本进行DAT评估，以改善检测条件。II期使用从有症状的CVL犬和临床健康犬采集的100份血清样本评估诊断准确性，比较四种不同的样本稀释剂。当使用2-ME、NAC或NAC+U时，CVL-DAT原型试剂盒表现出等效性能：敏感性为97.1%（CI：83-99.8%），特异性为97%（CI：88.5-99.5%），诊断准确性为97%（CI：90.8-99.2）。使用高岭土时，观察到敏感性为94.1%（CI：79-99%），特异性为97%（CI：88.5-99.5%），诊断准确性为96%（CI：89.5-98.7），四种试剂之间无统计学显著差异（p=1.0）。样本稀释剂中的NAC加尿素减少了非特异性凝集，促进了边界更清晰的尖锐蓝色斑点形成，因此被选为诊断犬VL的新型DAT原型（称为DAT-Canis）的一个组成部分。
