rKLO8，一种新型利什曼原虫衍生的重组免疫显性蛋白，可用于苏丹内脏利什曼病的敏感检测。

rKLO8, a novel Leishmania donovani - derived recombinant immunodominant protein for sensitive detection of visceral leishmaniasis in Sudan.

机构信息

Institute for Medical Microbiology and Hygiene, University of Marburg, Marburg, Germany.

出版信息

PLoS Negl Trop Dis. 2013 Jul 18;7(7):e2322. doi: 10.1371/journal.pntd.0002322. Print 2013.

BACKGROUND

For effective control of visceral leishmaniasis (VL) in East Africa, new rapid diagnostic tests are required to replace current tests with low sensitivity. The aim of this study is to improve diagnosis of VL in East Africa by testing a new antigen from an autochthonous L. donovani strain in Sudan.

METHODOLOGY AND PRINCIPLE FINDINGS

We cloned, expressed and purified a novel recombinant protein antigen of L. donovani from Sudan, designated rKLO8, that contains putative conserved domains with significant similarity to the immunodominant kinesin proteins of Leishmania. rKLO8 exhibited 93% and 88% amino acid identity with cloned kinesin proteins of L. infantum (synonymous L. chagasi) (K39) and L. donovani (KE16), respectively. We evaluated the diagnostic efficiency of the recombinant protein in ELISA for specific detection of VL patients from Sudan. Data were compared with a rK39 ELISA and two commercial kits, the rK39 strip test and the direct agglutination test (DAT). Of 106 parasitologically confirmed VL sera, 104 (98.1%) were tested positive by rKLO8 as compared to 102 (96.2%) by rK39. Importantly, the patients' sera showed increased reactivity with rKLO8 than rK39. Specificity was 96.1% and 94.8% for rKLO8- and rK39 ELISAs, respectively. DAT showed 100% specificity and 94.3% sensitivity while rK39 strip test performed with 81.1% sensitivity and 98.7% specificity.

CONCLUSION

The increased reactivity of Sudanese VL sera with the rKLO8 makes this antigen a potential candidate for diagnosis of visceral leishmaniasis in Sudan. However, the suitability at the field level will depend on its performance in a rapid test format.

背景

为了有效控制东非内脏利什曼病（VL），需要新的快速诊断检测方法来替代当前敏感性低的检测方法。本研究的目的是通过检测苏丹当地一株利什曼原虫株的新型抗原，来提高东非 VL 的诊断水平。

方法和主要发现

我们从苏丹克隆、表达和纯化了一种新的利什曼原虫重组蛋白抗原 rKLO8，该抗原包含与利什曼属免疫优势驱动蛋白具有显著相似性的假定保守结构域。rKLO8 与克隆的婴儿利什曼原虫（同义的恰加斯利什曼原虫）（K39）和利什曼原虫（KE16）的驱动蛋白分别具有 93%和 88%的氨基酸同一性。我们评估了重组蛋白在 ELISA 中检测苏丹内脏利什曼病患者的诊断效率。数据与 rK39 ELISA 和两种商业试剂盒（rK39 条带试验和直接凝集试验（DAT））进行了比较。在 106 例经寄生虫学证实的 VL 血清中，rKLO8 检测出 104 例（98.1%）阳性，rK39 检测出 102 例（96.2%）阳性。重要的是，患者血清与 rKLO8 的反应性比 rK39 更强。rKLO8 和 rK39 ELISA 的特异性分别为 96.1%和 94.8%。DAT 的特异性为 100%，敏感性为 94.3%，而 rK39 条带试验的敏感性为 81.1%，特异性为 98.7%。