title: Diagnostic values of parasite-specific antibody detections in saliva and urine in comparison with serum in opisthorchiasis.
abstract: Infection by the liver fluke (Opisthorchis viverrini) causes hepatobiliary disease and bile duct cancer (cholangiocarcinoma, CCA) in endemic areas in Southeast Asia. Measurements of humoral immune response particularly parasite-specific antibodies are useful not only for serodiagnosis but they have been implicated as risk factors of CCA. In this study, we used indirect Enzyme Immunosorbent Assay (ELISA) to measure O. viverrini-specific immunoglobulins in serum, urine and saliva and assessed efficacies in diagnosis of opisthorchiasis and evaluated the relationship of antibodies among clinical specimens in a sample population in endemic areas in Khon Kaen, Thailand. By employing the Receiver Operation Characteristics (ROC) analysis, diagnostic efficacy based upon the area under the curve (AUC) revealed that serum, salivary IgG and IgA performed better than urine for diagnosis of opisthorchiasis. Seropositive cases were found in both parasite egg-negative as well as O. viverrini egg-positive groups. The levels of serum IgG correlated with intensity of O. viverrini infection (P<0.05). Diagnostic sensitivities based on serum and salivary IgG, IgA also positively associated with the intensity of infection. Correlations between serum antibodies and those in saliva were found to be greater in egg-negative than egg-positive individuals for O. viverrini. Our findings indicated a complex interrelation between antibody responses in different clinical specimens triggered by liver fluke infection. More comprehensive examinations are needed to determine the potential utility of salivary antibody detection which, in combination with the conventional fecal examination method, may better assist in the identification of individuals with opisthorchiasis. Furthermore, it may provide a better indicator of the risk of disease, particularly CCA.
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Prajak
authors.initials: P
authors.lastname: Sawangsoda
authors.forename: Jiraporn
authors.initials: J
authors.lastname: Sithithaworn
authors.forename: Smarn
authors.initials: S
authors.lastname: Tesana
authors.forename: Somchai
authors.initials: S
authors.lastname: Pinlaor
authors.forename: Thidarut
authors.initials: T
authors.lastname: Boonmars
authors.forename: Eimorn
authors.initials: E
authors.lastname: Mairiang
authors.forename: Puangrat
authors.initials: P
authors.lastname: Yongvanit
authors.forename: Kunyarat
authors.initials: K
authors.lastname: Duenngai
authors.forename: Paiboon
authors.initials: P
authors.lastname: Sithithaworn
mesh_terms: D000085:Acetates / Q000737:chemistry; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis* / Q000097:blood / Q000652:urine; D000947:Antigens, Helminth / Q000032:analysis* / Q000097:blood / Q000652:urine; D019540:Area Under Curve; D018281:Cholangiocarcinoma / Q000175:diagnosis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005243:Feces / Q000469:parasitology; D005260:Female; D005557:Formaldehyde / Q000737:chemistry; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis / Q000097:blood / Q000652:urine; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood / Q000652:urine; D007136:Immunoglobulins / Q000032:analysis* / Q000097:blood / Q000652:urine; D008297:Male; D008875:Middle Aged; D009889:Opisthorchiasis / Q000175:diagnosis* / Q000276:immunology; D009891:Opisthorchis / Q000276:immunology*; D012372:ROC Curve; D012463:Saliva / Q000276:immunology; D012680:Sensitivity and Specificity; D013785:Thailand
chemical_list: D000085:Acetates; D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007136:Immunoglobulins; D005557:Formaldehyde; C007650:ethyl acetate