Goncalves Ricardo, Silva Soraia Oliveira, de Almeida Gregório Guilherme, de Souza Carolina Carvalho, Tafuri Wagner Luiz, Norma Melo M
Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av Antonio Carlos 6627, Belo Horizonte, MG, CEP31270-901, Brazil.
Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av Antonio Carlos 6627, Belo Horizonte, MG, CEP31270-901, Brazil.
BMC Vet Res. 2018 Dec 17;14(1):403. doi: 10.1186/s12917-018-1730-7.
Despite the very low or absent parasitism in the lungs, the interstitial pneumonitis is a common lesion found in humans and dogs with visceral leishmaniasis. The lung is a neglected organ in the study of dogs and humans with visceral leishmaniasis, but interstitial pneumonitis represents an important lesion characterized by thickening of the alveolar septum due to fibrosis and inflammatory exudate, and its pathogenesis is still uncertain. In this study, the polymerase chain reaction (PCR) was used to detect Leishmania infantum in paraffin-embedded lung biopsies from naturally infected dogs from an endemic area in Minas Gerais State, Brazil; PCR was compared to histological and immunohistochemical techniques for detecting Leishmania.
Eighteen dogs in which leishmaniasis had been diagnosed by serological tests - indirect immunofluorescence assay (IFAT), enzyme-linked immunosorbent assay (ELISA) and complement fixation tests (CFT) - were classified as asymptomatic, oligosymptomatic or symptomatic. Nine of the 18 dogs studied had a positive PCR (50%) but parasites were not detected by histopathological and immunocytochemistry methods.
These data indicate that PCR on DNA extracted from paraffin-embedded tissue is a valuable method for detecting Leishmania infantum parasites in lungs of naturally infected dogs, despite the apparent absence of parasites from standard HE (hematoxylin and eosin) stained slides and of labeled parasites from immunocytochemical preparations.
尽管肺部寄生虫感染率极低或不存在，但间质性肺炎是人类和犬内脏利什曼病中常见的病变。在犬类和人类内脏利什曼病的研究中，肺是一个被忽视的器官，但间质性肺炎是一种重要的病变，其特征是由于纤维化和炎性渗出导致肺泡间隔增厚，其发病机制仍不确定。在本研究中，采用聚合酶链反应（PCR）检测来自巴西米纳斯吉拉斯州一个流行地区自然感染犬的石蜡包埋肺活检组织中的婴儿利什曼原虫；将PCR与检测利什曼原虫的组织学和免疫组织化学技术进行比较。
通过血清学检测——间接免疫荧光试验（IFAT）、酶联免疫吸附试验（ELISA）和补体结合试验（CFT）——诊断为利什曼病的18只犬被分类为无症状、轻度症状或有症状。在研究的18只犬中，有9只PCR呈阳性（50%），但组织病理学和免疫细胞化学方法未检测到寄生虫。
这些数据表明，尽管从标准苏木精和伊红（HE）染色切片中明显未发现寄生虫，且免疫细胞化学制剂中未发现标记寄生虫，但对石蜡包埋组织中提取的DNA进行PCR是检测自然感染犬肺部婴儿利什曼原虫寄生虫的一种有价值的方法。
