Lima Luciana Vieira do R, Carneiro Liliane Almeida, Campos Marliane Batista, Vasconcelos Dos Santos Thiago, Ramos Patrícia Karla, Laurenti Márcia Dalastra, Teixeira Claudio Eduardo C, Silveira Fernando T
Parasitology Department, Evandro Chagas Institute (Surveillance Secretary of Health, Ministry of Health), Ananindeua, Pará State, Brazil.
National Center of Primates (Surveillance Secretary of Health, Ministry of Health), Ananindeua, Pará state, Brazil.
Parasite. 2017;24:37. doi: 10.1051/parasite/2017039. Epub 2017 Oct 13.
We present here a cross-sectional study analyzing the IgG1 and IgG2 immune responses to natural canine Leishmania (L.) infantum chagasi-infection and their relationships with delayed-type hypersensitivity (DTH) in 50 mongrel dogs with previous positive serodiagnoses (IFAT-IgG) (56% with subclinical status [= apparently healthy] and 44% clinically sick), living in endemic areas for visceral leishmaniasis in the Brazilian Amazon. IgG1 and IgG2 responses were measured using commercial polyclonal antibodies in ELISA, while DTH was elicited by intradermal skin test using cultured promastigotes L. (L.) i. chagasi-antigen. Data analyses used Chi-square and Pearson's r coefficient (95% confidence interval). Regarding DTH and the clinical statuses of dogs, it was noted that 100% of the animals showing positive DTH (n = 8) were from the subclinical group, while 100% showing negative DTH were from the clinically sick group; higher IgG2 than IgG1 responses were observed in both clinical groups. However, when this comparison was made between the subclinical and sick groups, higher IgG1 responses were noted in the dogs from the sick rather than the subclinical group, while no differences were noted between the IgG2 responses in the dogs from both clinical groups. Additionally, we found lower IgG1 responses in dogs from the subclinical group showing positive DTH than in the dogs from the subclinical or sick groups with negative DTH; no differences were found between the IgG2 responses of these two clinical groups. These findings suggest that the IgG1, but not the IgG2, response is associated with susceptibility to canine visceral leishmaniasis (CVL).
我们在此呈现一项横断面研究，分析了50只先前血清学诊断（间接荧光抗体试验-IgG）呈阳性的杂种犬对自然感染犬利什曼原虫（婴儿利什曼原虫恰加斯亚种）的IgG1和IgG2免疫反应，以及它们与迟发型超敏反应（DTH）的关系。这些犬生活在巴西亚马逊地区内脏利什曼病的流行区，其中56%处于亚临床状态（即看似健康），44%为临床患病。采用商业多克隆抗体通过酶联免疫吸附测定（ELISA）检测IgG1和IgG2反应，同时使用培养的前鞭毛体婴儿利什曼原虫恰加斯亚种抗原通过皮内皮肤试验引发DTH。数据分析采用卡方检验和皮尔逊r系数（95%置信区间）。关于DTH和犬的临床状态，发现100%表现为DTH阳性的动物（n = 8）来自亚临床组，而100%表现为DTH阴性的动物来自临床患病组；在两个临床组中均观察到IgG2反应高于IgG1反应。然而，当在亚临床组和患病组之间进行此比较时，发现患病组犬的IgG1反应高于亚临床组，而两个临床组犬的IgG2反应之间未发现差异。此外，我们发现亚临床组中表现为DTH阳性的犬的IgG1反应低于亚临床组或DTH阴性的患病组犬；这两个临床组的IgG2反应之间未发现差异。这些发现表明，IgG1反应而非IgG2反应与犬内脏利什曼病（CVL）的易感性相关。
