Immunodiagnosis of opisthorchiasis using parasite cathepsin F.
Opisthorchis viverrini, a food-borne trematode parasite endemic in the lower Mekong countries, is conventionally diagnosed by stool examination. However, parasitological stool-based diagnosis can be unreliable in light infections. The goal of this study was to develop the immunodiagnosis of opisthorchiasis using cathepsin F cysteine protease of O. viverrini in both indirect and sandwich ELISA assays. A recombinant O. viverrini cathepsin F (rOv-CF) of 40 kDa was expressed in E. coli strain BL21 (DE3), affinity purified, and deployed in ELISA assays. Human sera from 272 cases were investigated by indirect rOv-CF-based ELISA. Positive antibody response to rOv-CF was found in 137 out of 272 cases (50.37 %) using a cutoff OD (0.400) determined by ROC analysis. In comparison to parasitological stool examined for fluke eggs, the gold standard, the rOv-CF indirect ELISA showed a sensitivity and specificity of 62.1 and 84.05 %, respectively. Serum antibody levels correlated well with egg counts per gram feces (EPG) (P < 0.001). In addition, chicken IgY antibody raised against rOv-CF was tested in a sandwich ELISA for detection of coproantigen in the feces of experimentally infected hamsters. The sandwich ELISA using this chicken IgY in combination with rabbit antibody to O. viverrini somatic antigens showed sensitivity and specificity of 93.3 and 78.57 %, respectively. Together, these findings indicated the potential of rOv-CF for diagnosis of opisthorchiasis, including for uses with chicken IgY for detection of coproantigens of O. viverrini.
WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.|Centre of Research Excellence for Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Bangkok, 10700, Thailand.
Salma
S
Teimoori
WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
Yuji
Y
Arimatsu
Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
Thewarach
T
Laha
Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
Sasithorn
S
Kaewkes
Department of Pathobiology, Faculty of Veterinary, Medicine, Khon Kaen University, Khon Kaen, Thailand.
Piya
P
Sereerak
Department of Pathobiology, Faculty of Veterinary, Medicine, Khon Kaen University, Khon Kaen, Thailand.
Sirikachorn
S
Tangkawattana
Department of Microbiology, Immunology and Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine and Health Sciences, George Washington University, Washington, DC, 20037, USA.
Paul J
PJ
Brindley
WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease), Tropical Disease Research Laboratory, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand. banchob@kku.ac.th.
Banchob
B
Sripa
D000818:Animals; D056646:Cathepsin F / Q000032:analysis* / Q000276:immunology; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005243:Feces / Q000469:parasitology; D006801:Humans; D007159:Immunologic Tests; D008297:Male; D009889:Opisthorchiasis / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology; D009891:Opisthorchis / Q000201:enzymology / Q000276:immunology* / Q000302:isolation & purification; D012372:ROC Curve; D011817:Rabbits; D012680:Sensitivity and Specificity
D056646:Cathepsin F
Cathepsin F; Coproantigen detection; Food-borne trematodiasis; Immunodiagnosis; Opisthorchiasis; Opisthorchis viverrini