The treatment against visceral leishmaniasis (VL) presents problems, mainly related to the toxicity and/or high cost of the drugs. In this context, a rapid and precise diagnosis of the disease should be performed, mainly to treat patients as soon as possible, aiming to reduce the treatment time and the toxicity of the therapeutics. In the present study, the diagnostic role of an amastigote-specific Leishmania protein was evaluated in the canine and human VL. Results showed that the recombinant protein (called rLiHyJ) and one specific B cell epitope (called PeptJ) predicted from protein sequence presented high sensitivity and specificity values to diagnose canine and human disease, showing also a low reactivity against cross-reactive samples. The rA2 protein and a parasite antigenic extract showed variable sensitivity and/or specificity values in the ELISA experiments. A prognostic evaluation of protein and peptide in the human VL indicated that specific IgG antibodies significantly decreased after treatment, when compared to be values obtained before therapy. The in vitro immunogenicity using rLiHyJ in peripheral blood mononuclear cell (PBMC) cultures collected of such patients and healthy subjects suggested that the protein induced lymphoproliferation and high IFN-γ production in the stimulated cells. In conclusion, although preliminary, results suggest that rLiHyJ and PeptJ could present distinct biotechnological applications in the canine and human VL.

内脏利什曼病（VL）的治疗存在问题，主要与药物的毒性和/或高成本有关。在这种情况下，应该对疾病进行快速而准确的诊断，主要是为了尽快治疗患者，以减少治疗时间和减少治疗剂的毒性。在本研究中，一种鞭毛体特定利什曼原虫的诊断作用在犬和人VL中评估蛋白。结果表明，从蛋白质序列预测的重组蛋白（称为rLiHyJ）和一个特定的B细胞表位（称为PeptJ）在诊断犬类和人类疾病方面具有很高的敏感性和特异性，对交叉反应性样品的反应性也很低。rA2蛋白和寄生虫抗原提取物在ELISA实验中显示出可变的灵敏度和/或特异性值。对人VL中蛋白质和肽的预后评估表明，与治疗前获得的值相比，治疗后特异性IgG抗体显着降低。在体外使用rLiHyJ免疫原性的外周血单核细胞（PBMC）从这类患者和健康受试者身上收集的培养物表明，该蛋白诱导了受刺激细胞的淋巴增殖和高IFN-γ产生。总之，尽管是初步的，但结果表明rLiHyJ和PeptJ可能在犬和人VL中呈现出独特的生物技术应用。