Tantrawatpan Chairat, Maleewong Wanchai, Wongkham Chaisiri, Wongkham Sopit, Intapan Pewpan M, Nakashima Kunio
Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Am J Trop Med Hyg. 2005 Jan;72(1):82-6.
Cathepsin L1, a cysteine protease secreted by the gastrodermis of juvenile and adult Fasciola gigantica, was expressed in Escherichia coli as a calmodulin binding peptide fusion protein with a molecular mass of approximately 35 kD. The recombinant cathepsin L1 (rCTL1) was tested for its antigenic potential in a cystatin capture enzyme-linked immunosorbent assay (ELISA) to diagnose human fascioliasis. The ELISA plates were sensitized with chicken egg cystatin and incubated with bacterial lysates containing the recombinant protein before the standard ELISA procedures were performed. Analysis of the sera of 13 patients infected with F. gigantica (group 1), 204 patients with other parasitic infections (group 2), 32 cholangiocarcinoma patients (group 3), and 42 healthy controls (group 4) showed that the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of this ELISA using rCTL1 were 100%, 98.92%, 98.97%, 81.25%, and 100%, respectively. These results indicate that this assay has high sensitivity and specificity in the diagnosis of human fascioliasis. In addition, we have produced sufficient amounts of antigen for use in diagnosis.
组织蛋白酶L1是由巨片形吸虫幼虫和成虫的胃皮层分泌的一种半胱氨酸蛋白酶，它在大肠杆菌中表达为一种分子量约为35kD的钙调蛋白结合肽融合蛋白。在胱抑素捕获酶联免疫吸附测定（ELISA）中检测重组组织蛋白酶L1（rCTL1）的抗原潜力，以诊断人体片形吸虫病。在进行标准ELISA程序之前，用鸡卵胱抑素致敏ELISA板，并与含有重组蛋白的细菌裂解物一起孵育。对13例感染巨片形吸虫的患者（第1组）、204例其他寄生虫感染患者（第2组）、32例胆管癌患者（第3组）和42例健康对照者（第4组）的血清分析表明，使用rCTL1的该ELISA的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为100%、98.92%、98.97%、81.25%和100%。这些结果表明，该检测方法在人体片形吸虫病的诊断中具有高敏感性和特异性。此外，我们已经制备了足够量的抗原用于诊断。
