Plasma metabolomics of the time resolved response to Opisthorchis felineus infection in an animal model (golden hamster, Mesocricetus auratus).

BACKGROUND: Opisthorchiasis is a hepatobiliary disease caused by flukes of the trematode family Opisthorchiidae. Opisthorchiasis can lead to severe hepatobiliary morbidity and is classified as a carcinogenic agent. Here we investigate the time-resolved metabolic response to Opisthorchis felineus infection in an animal model. METHODOLOGY: Thirty golden hamsters were divided in three groups: severe infection (50 metacercariae/hamster), mild infection (15 metacercariae/hamster) and uninfected (vehicle-PBS) groups. Each group consisted of equal number of male and female animals. Plasma samples were collected one day before the infection and then every two weeks up to week 22 after infection. The samples were subjected to 1H Nuclear Magnetic Resonance (NMR) spectroscopy and multivariate statistical modelling. PRINCIPAL FINDINGS: The time-resolved study of the metabolic response to Opisthorchis infection in plasma in the main lines agrees with our previous report on urine data. The response reaches its peak around the 4th week of infection and stabilizes after the 10th week. Yet, unlike the urinary data there is no strong effect of the gender in the data and the intensity of infection is presented in the first two principal components of the PCA model. The main trends of the metabolic response to the infection in blood plasma are the transient depletion of essential amino acids and an increase in lipoprotein and cholesterol concentrations. CONCLUSIONS: The time resolved metabolic signature of Opisthorchis infection in the hamster's plasma shows a coherent shift in amino acids and lipid metabolism. Our work provides insight into the metabolic basis of the host response on the helminth infection.

Development of an Immunochromatographic Point-of-Care Test for Serodiagnosis of Opisthorchiasis and Clonorchiasis.

Chronic infections with the food-borne liver flukes, Opisthorchis viverrini or Clonorchis sinensis, associate with cholangiocarcinoma, bile duct cancer, which generally has a poor prognosis. We have produced a rapid and simple immunochromatographic test (ICT) kit for the diagnosis of opisthorchiasis and clonorchiasis by the detection of IgG antibodies in human infection sera. Sera from volunteers with proven opisthorchiasis and several other parasitic diseases and from healthy controls were evaluated for the presence of liver fluke infection-specific antibodies using a preparation of excretory-secretory antigen from adult stage O. viverrini absorbed onto ICT strips. Diagnostic values were compared with an ELISA. The diagnostic sensitivity, specificity, and positive and negative predictive values of the ELISA were 100%, 98.3%, 97.9%, and 100%, whereas those for the ICT were 94.6%, 91.2%, 89.7%, and 95.4%, respectively. There was 91.7% concordance between the ICT with ELISA, and differences in performance between the tests were not statistically significant (P > 0.05). Twenty-seven of 30 (90%) of the clonorchiasis sera also were positive by ICT. This new ICT provides a facile, rapid test for point-of-care testing tool, which can be used at the bedside without the need for sophisticated equipment. Moreover, the ICT can be anticipated to supplement stool examination as a screening tool in the clinic for the diagnosis of opisthorchiasis and clonorchiasis, and in addition, it may be useful in screens of populations at risk of liver fluke infection-associated cholangiocarcinoma.

Clonorchis sinensis omega-class glutathione transferases are reliable biomarkers for serodiagnosis of clonorchiasis and opisthorchiasis.

OBJECTIVES: To determine the potential for immunodiagnostic application of two recombinant forms of Clonorchis sinensis omega-class glutathione transferases (rCsGSTo1 and rCsGSTo2) against human small liver-fluke C. sinensis and Opisthorchis viverrini infections. METHODS: Specific antibody levels against rCsGSTo1 and rCsGSTo2 in patients' sera of egg-positive opisthorchiasis (n = 87) and clonorchiasis (n = 120), as well as those in sera from patients with other helminthic infections (n = 252) and healthy controls (n = 40) were retrospectively analysed by ELISA. RESULTS: We observed highly positive correlation coefficients between specific antibody levels against rCsGSTo1 and rCsGSTo2 and egg counts per gramme of faeces (EPG) of patients with opisthorchiasis (n = 87; r = 0.88 for rCsGSTo1 and r = 0.90 for rCsGSTo2). Sera from opisthorchiasis patients whose EPG counts >100 (n = 43) revealed high antibody titres against both antigens. Patients' sera with low EPG counts (<100, n = 44) also exhibited reliable sensitivities of 93.2% and 97.7% for rCsGSTo1 and rCsGSTo2, respectively. Sera from clonorchiasis patients showed sensitivities of 90% (108/120 samples) and 89.2% (107/120 sera) for rCsGSTo1 and rCsGSTo2. Overall diagnostic sensitivities for liver-fluke infections were 92.3% for rCsGSTo1 (191/207 samples) and 93.2% for rCsGSTo2 (193/207 samples). Specificities were 89.7% (rCsGSTo1) and 97.6% (rCsGSTo2). CONCLUSIONS: Detection of specific antibody levels against rCsGSTo1 or rCsGSTo2 might be promising for the serodiagnosis of patients infected with these two phylogenetically close carcinogenic liver-flukes.

Social defeat stress exacerbates the blood abnormalities in Opisthorchis felineus-infected mice.

A model of chronic opisthorchiasis combined with social stress is examined; this situation is more likely for humans and animals than a separate impact of the infectious factor. For this purpose, we evaluated the effects of Opisthorchis felineus ("OP" group) and 30-day social stress (confrontations between males, "SS" group) alone and in combination ("OP + SS" group) in inbred C57BL/6 male mice and compared these effects according to the parameters listed below. The animals exposed to neither factor formed the control group ("CON"). All animals were assayed for blood biochemical parameters, changes in blood cell composition, and pattern of bone marrow hematopoiesis. By the end of the experiment, we have observed crucial effects of the two factors on the blood and liver of "OP" and "OP + SS". Eosinophil and basophil counts increased and relative segmented neutrophil and monocyte counts decreased in "OP + SS" mice on the background of activated myelopoiesis, mainly determined by social stress. Despite depressed erythropoiesis, "OP" mice displayed no changes in the relative peripheral erythrocyte counts. On the contrary, social stress, which stimulated erythropoiesis in "SS" and "OP + SS" mice, was accompanied by a decrease in the relative erythrocyte counts and hematocrit. Hepatosplenomegaly was observed on the background of these two impacts. Changes in transaminase (ALT and AST) and alkaline phosphatase activities as well as an increase in cholesterol and product of lipid peroxidation suggest a pronounced destruction of the liver. Altogether, social stress exacerbates many of the assayed blood parameters in the mice infected with the liver fluke.

Differential Protein Expression Marks the Transition From Infection With Opisthorchis viverrini to Cholangiocarcinoma.

Parts of Southeast Asia have the highest incidence of intrahepatic cholangiocarcinoma (CCA) in the world because of infection by the liver fluke Opisthorchis viverrini (Ov). Ov-associated CCA is the culmination of chronic Ov-infection, with the persistent production of the growth factors and cytokines associated with persistent inflammation, which can endure for years in Ov-infected individuals prior to transitioning to CCA. Isobaric labeling and tandem mass spectrometry of liver tissue from a hamster model of CCA was used to compare protein expression profiles from inflammed tissue (Ovinfected but not cancerous) versus cancerous tissue (Ov-induced CCA). Immunohistochemistry and immunoblotting were used to verify dysregulated proteins in the animal model and in human tissue. We identified 154 dysregulated proteins that marked the transition from Ov-infection to Ov-induced CCA, i.e. proteins dysregulated during carcinogenesis but not Ov-infection. The verification of dysregulated proteins in resected liver tissue from humans with Ov-associated CCA showed the numerous parallels in protein dysregulation between human and animal models of Ov-induced CCA. To identify potential circulating markers for CCA, dysregulated proteins were compared with proteins isolated from exosomes secreted by a human CCA cell line (KKU055) and 27 proteins were identified as dysregulated in CCA and present in exosomes. These data form the basis of potential diagnostic biomarkers for human Ov-associated CCA. The profile of protein dysregulation observed during chronic Ovinfection and then in Ov-induced CCA provides insight into the etiology of an infection-induced inflammation-related cancer.

Development of an ELISA using anti-idiotypic antibody for diagnosis of opisthorchiasis.

Monoclonal antibody specific for an epitope of cretory-secretory antigen protein of Opisthorchis felineus (Rivolta, 1884) (Trematoda: Opisthorchiidae) with a molecular weight of 28 kDa was used in a sandwich enzyme-linked immunosorbent assay (ELISA) for immobilisation of liver fluke specific antigen to the solid phase. Examination of human sera by this ELISA compared with commercial assays demonstrated that the monoclonal antibody epitope is located within this significant parasite protein. Anti-idiotypic antibody specific for the paratope of this monoclonal antibody was obtained by a hybridoma technique. Mimicking an epitope of excretory-secretory antigen of O. felineus, it had the capacity to bind specific antibody and elicit an antibody response. The value of anti-idiotypic antibody as a substitute for the liver fluke antigen was tested by ELISA using serum samples of infected dogs. Anti-idiotypic antibody proved to be of value in both an indirect-ELISA and a competitive-ELISA for diagnosis of opisthorchiasis. Mature trematodes were isolated from all infected animals. The faecal egg counts were negative in dogs with a relatively small number of parasites, despite finding antibodies in serum by ELISA. Substitution of parasite antigen with anti-idiotype avoids the use of experimental animals and also reduces time-consuming steps of antigen preparation.

Pharmacokinetic Study of Praziquantel Enantiomers and Its Main Metabolite R-trans-4-OH-PZQ in Plasma, Blood and Dried Blood Spots in Opisthorchis viverrini-Infected Patients.

BACKGROUND: Praziquantel (PZQ) is the treatment of choice for infections with the liver fluke Opisthorchis viverrini, a major health problem in Southeast Asia. However, pharmacokinetic (PK) studies investigating the disposition of PZQ enantiomers (R- and S-PZQ) and its main metabolite, R-trans-4-OH-PZQ, in diseased patients are lacking. The implementation of a dried blood spot (DBS) sampling technique would ease the performance of PK studies in remote areas without clinical facilities. The aim of the present study is to provide data on the disposition of PZQ enantiomers and R-trans-4-OH-PZQ in opisthorchiasis patients and to validate the use of DBS compared to plasma and blood sampling. METHODOLOGY/PRINCIPAL FINDINGS: PZQ was administered to nine O. viverrini-infected patients at 3 oral doses of 25 mg/kg in 4 h intervals. Plasma, blood and DBS were simultaneously collected at selected time points from 0 to 24 h post-treatment. PK parameters were determined using non-compartmental analysis. Drug concentrations and areas under the curve (AUC0-24h) measured in the 3 matrices were compared using Bland-Altman analysis. We observed plasma AUC0-24hs of 1.1, 9.0 and 188.7 µg/ml*h and half-lives of 1.1, 3.3 and 6.4 h for R-PZQ, S-PZQ and R-trans-4-OH, respectively. Maximal plasma concentrations (Cmax) of 0.2, 0.9 and 13.9 µg/ml for R-PZQ, S-PQZ and R-trans-4-OH peaked at 7 h for PZQ enantiomers and at 8.7 h for the metabolite. Individual drug concentration measurements and patient AUC0-24hs displayed ratios of blood or DBS versus plasma between 79-94% for R- and S-PZQ, and between 108-122% for R-trans-4-OH. CONCLUSIONS/SIGNIFICANCE: Pharmacodynamic (PD) in vitro studies on PZQ enantiomers and R-trans-4-OH-PZQ are necessary to be able to correlate PK parameters with efficacy. DBS appears to be a valid alternative to conventional venous sampling for PK studies in PZQ-treated patients.

Serum Antibody Ig G and Ig M Titers for Opisthorchis felineus Correlate with Eggs in Faeces--a Comprehensive Study in Chuvash Republic, Russia.

The Cholangiocarcinoma is a. The risk of development of cholangiocarcinoma, generally a rare type of a liver tumor, increases during infection of Opisthorchiasis. For this reason the timely detection of Opisthorchiasis is important for Cholangiocarcinoma prevention. There are many studies which concern the detection of pathogenesis of Opisthorchis viverrini infection but a little known about Opisthorchis felineus. In this study we investigate a correlation of the eggs which are found in a faeces and are comparable with a serum Ig G and Ig M antibody level that were detected with ELISA test in a large group of patients. The result is showing positive correlation between evidence of the Opisthorchis felineus eggs that were found in a faeces and antibody Ig G and Ig M level in a serum. Moreover the combination of two methods can improve the Opisthorchiasis diagnostic: the serum antibody and faeces investigation of eggs.

A Promising Serum Autoantibody Marker, Anti-Heat Shock Protein 90α, for Cholangiocarcinoma.

The present study was designed to investigate cholangiocarcinoma (CCA) antibodies in hamster serum. Hamster CCA cell lines were processed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A candidate biomarker was confirmed by immunoprecipitation and western blot, and was further analyzed using ELISA and sera from normal control hamsters, hamsters with opisthorchiasis and hamsters with various stages of CCA, as well as from CCA patients and healthy individuals. One candidate marker was identified as HSP90α, as indicated by a high level of anti-HSP90α in hamster CCA sera. It was found that the levels of anti-HSP90α were specifically elevated in the sera of hamsters with CCA compared with other groups and progressively increased with the clinical stage. At the cut-off point of 0.4850 on the receiver operating characteristic curve, anti-HSP90α could discriminate CCA from healthy control groups with a sensitivity of 76.2%, specificity of 71.4% and total accuracy 75.5%. In the present study, we have shown that anti-HSP90α may be a potential useful serum biomarker to discriminate CCA cases from healthy persons.

Circulating miR-192 in liver fluke-associated cholangiocarcinoma patients: a prospective prognostic indicator.

BACKGROUND: This study aimed to investigate the miR-192 levels in patients' sera of liver fluke-associated cholangiocarcinoma (CCA) for a prospective prognostic indicator. METHODS: MicroRNA polymerase chain reaction (PCR) array was performed using pooled serum samples from 11 CCA patients and nine healthy subjects. Selected miRNAs were verified for the differential levels in both sera and tumor tissues (of patients and Opisthorchis viverrini (Ov)-induced CCA model) using TaqMan miRNA expression assay. RESULTS: Our results demonstrated that miR-192 was significantly higher in the serum of CCA patients than that in healthy subjects giving a sensitivity of 74% and specificity of 72% (area under the curve [AUC] = 0.803; 95% confidence interval [CI], 0.708-0.897, P < 0.0001). Serum miR-192 examined in Ov infected subjects and subjects with periductal fibrosis were increased but not statistically significantly when compared with healthy subjects. High levels of serum miR-192 were significantly correlated with lymph node metastasis (P = 0.047) and shorter survival compared with individuals with low levels of serum miR-192 (hazard ratio [HR] 2.076, 95% CI 1.004-4.291, P = 0.049). We also found that the expression levels of miR-192 appeared to be elevated in both CCA tissues of patients and in Ov-induced CCA tissues of a hamster model. CONCLUSIONS: This finding indicates that elevated levels of miR-192 may be involved in CCA genesis and have a potential utility as a noninvasive prognostic indicator for CCA patients.

Opisthorchis viverrini: analysis of the sperm-specific rhophilin associated tail protein 1-like.

Concurrent deficiency of rhophilin associated tail protein (ROPN1) and ROPN1-like (ROPN1L) in mice causes structural abnormalities and immotility of sperm and thereby infertility. In the present research, ROPN1L of the human liver fluke Opisthorchis viverrini was molecularly characterized and showed unexpected potential as a diagnostic tool. ROPN1L transcripts were detected in 2-week-old juveniles by RT-PCR. Immunohistochemical analysis of the adult worm localized the protein in testis lobes, seminal vesicle and receptacle and immunoelectron microscopic analysis revealed its location on the tail of spermatozoa. Interestingly, sera of experimentally infected hamsters and sera of individuals suffering from opisthorchiasis showed reactivity to recombinant OvROPN1L (rOvROPN1L). The protein shows modest conservation to the human homolog at 47.2% sequence identity and a mouse anti-rOvROPN1L antiserum was not reactive with sperm protein extracts from hamsters, mice and rats. Unsurprisingly, conservation is higher in trematodes, e.g. 78.4% and 71.2% identity to Fasciola gigantica and Schistosoma haematobium, respectively and evaluation of diagnostic specificity is required using sera of individuals suffering from different trematodiases in Thailand.

Increase of exostosin 1 in plasma as a potential biomarker for opisthorchiasis-associated cholangiocarcinoma.

A proteomic-based approach was used to search for potential markers in the plasma of hamsters in which cholangiocarcinoma (CCA) was induced by Opisthorchis viverrini infection and N-nitrosodimethylamine treatment. The plasma proteins of CCA-induced hamsters were resolved by 1-D PAGE, digested by trypsin, and analyzed by LC-MS/MS. From the criteria of protein ID scores >15 and an overexpression of at least three times across all time points, 37 proteins were selected. These overexpressed proteins largely consisted of signal transduction, structural, transport, and transcriptional proteins in the order. Among the most frequently upregulated proteins, exostosin 1 (EXT1) was selected for further validation. By western blot analysis, the EXT1 expression level in the plasma of hamster CCA was significantly higher than that of controls at 1 month and thereafter. Immunohistochemistry revealed that EXT1 was expressed at vascular walls and fibroblasts at 21 days (before tumor onset) and at 2 months (early CCA) posttreatment. Its expression was also observed in bile duct cancer cells during tumor progression at 6 months posttreatment. In the human CCA tissue microarray, EXT1 immunoreactivity was found not only in vascular walls and fibroblasts but also in bile duct cancer cells and was positive in 89.7 % (61/68) of the cases. By ELISA and immunoblotting, plasma EXT1 level was significantly higher in human CCA compared to healthy controls. In conclusion, these results suggest that increased expression of EXT1 level in the plasma might be involved in CCA genesis and might be a potential biomarker of CCA.

[Experience of using reamberin for detoxification therapy at the stage of deworming in children with chronic opisthorchiasis].

The study presents data on the reversible aggregation of erythrocytes in 50 children with chronic opisthorchiasis and 45 children with inflammatory diseases of the upper digestive tract without opisthorchiasis (chronic gastroduodenitis, duodenal ulcers), all patients aged from 7 to 17 years. The results of using reamberin for detoxification therapy at the stage of deworming in children with chronic opisthorchiasis are assessed.

Proteomic identification of plasma protein tyrosine phosphatase alpha and fibronectin associated with liver fluke, Opisthorchis viverrini, infection.

Opisthorchiasis caused by Opisthorchis viverrini induces periductal fibrosis via host immune/inflammatory responses. Plasma protein alteration during host-parasite interaction-mediated inflammation may provide potential diagnostic and/or prognostic biomarkers. To search for target protein changes in O. viverrini-infected hamsters, a 1-D PAGE gel band was trypsin-digested and analyzed by a LC-MS/MS-based proteomics approach in the plasma profile of infected hamsters, and applied to humans. Sixty seven proteins were selected for further analysis based on at least two unique tryptic peptides with protein ID score >10 and increased expression at least two times across time points. These proteins have not been previously identified in O. viverrini-associated infection. Among those, proteins involved in structural (19%), immune response (13%), cell cycle (10%) and transcription (10%) were highly expressed. Western blots revealed an expression level of protein tyrosine phosphatase alpha (PTPα) which reached a peak at 1 month and subsequently tended to decrease. Fibronectin significantly increased at 1 month and tended to increase with time, supporting proteomic analysis. PTPα was expressed in the cytoplasm of inflammatory cells, while fibronectin was observed mainly in the cytoplasm of fibroblasts and the extracellular matrix at periductal fibrosis areas. In addition, these protein levels significantly increased in the plasma of O. viverrini-infected patients compared to healthy individuals, and significantly decreased at 2-months post-treatment, indicating their potential as disease markers. In conclusion, our results suggest that plasma PTPα and fibronectin may be associated with opisthorchiasis and the hamster model provides the basis for development of novel diagnostic markers in the future.

[Thrombocytic and coagulation hemostasis in pregnant women living in the Ob-Irtysh river basin with chronic opisthorchiasis].

Opisthorchiasis that is widely spreading in Russia and CIS countries was and remains a serious social, medical, and scientific problem. Local or imported cases of opisthorchiasis have been notified in 87.6% of the administrative territories of Russia. The world's largest focus of opisthorchiasis is the Ob-Irtysh river basin with natural preconditions for its high infection in fish. The main clinical manifestations of Opisthorchis infestation are associated with liver damage caused by the obligate presence of Opisthorchis in the bile capillaries with evolving cholangitis, cholangiocholecystitis, and cholangiopancreatitis. Opisthorchis complicates the course of many diseases, affecting gestation, labor, and postpartum. The state of thrombocytic and coagulation hemostasis was analyzed in different period of pregnancy and postpartum (days 2-4), by using the course of pregnancy in the inhabitants of the hyperendemic focus of Opisthorchis infestation (the Ob-Irtysh basin) as an example. In the newcomers, pregnancy develops in the presence of platelet hyperaggregation and accelerated continuous blood clotting. In pregnant women who belong to native little peoples (Khanty, Mansi), opisthorchiasis induces no significant changes in the hemostatic potential.

High prevalence of Opisthorchis viverrini infection in reservoir hosts in four districts of Khon Kaen Province, an opisthorchiasis endemic area of Thailand.

Khon Kaen, a northeastern province of Thailand, has been considered as one of the human opisthorchiasis endemic areas with continuing high prevalence. Unsuccessful eradication of the disease is probably from the culture of eating raw and undercooked fish of local residence and the parasitic persistency in animal reservoir hosts, such as cats and dogs. In cooperation with the other human opisthorchiasis control programs in an endemic area of 29 villages in Ban Haet, Ban Phai, Chonnabot and Muncha Khiri Districts, Khon Kaen, this study investigated the prevalence of Opisthorchis viverrini infection using a formalin-ether sedimentation method as the gold standard, and hematology and blood chemistry of the reservoir hosts in this endemic area. The results showed that cats had much higher prevalence (76 of 214, 35.51%) than dogs (3 of 821, 0.37%). Hematology between the infected and uninfected cats was not different. Complete blood count and biochemistry reflected some altered hepatic functions. However, only severely infected cats showed apparent clinical signs, including lethargy, diarrhea, ocular and nasal discharges. Moreover, the ultrasonogram of infected cats with very high egg per gram (>1500 EPG) showed apparent thickening of the gall bladder wall with hyperechoicity of hepatic parenchyma. This study suggests that cat is the most important animal reservoir of human opisthorchiasis, especially in this endemic area. It is also interesting that villages with infection are mostly located in the vicinity of Chi River and two large water reservoirs (Lawa and Nong Kongkaew Lakes), but people without infection were away from Chi River, on the south of Kudkhow Lake. Further investigation on this particular geofactor is essential for effective opisthorchiasis control programs.

A novel carbohydrate antigen expression during development of Opisthorchis viverrini- associated cholangiocarcinoma in golden hamster: a potential marker for early diagnosis.

Poor prognosis of cholangiocarcinoma (CCA) is primarily due to delayed diagnosis because of the lack of appropriate tumor marker(s) to detect cancer development at an early stage. We have recently established a S121 monoclonal antibody (mAb) which recognizes an unidentified glycan epitope on MUC5AC, designated as CCA-associated carbohydrate antigen (CCA-CA). This antigen is expressed in human CCA cells but not in normal biliary epithelia. Detection of CCA-CA effectively distinguished CCA patients' sera from normal control sera with high specificity and sensitivity. In the present study, we examined a time profile of the expression of CCA-CA by immunohistochemical methods in the liver tissues of Opisthorchis viverrini (Ov)-associated CCA in a hamster model. Hamsters were divided into four groups; non-treated, Ov infected, NDMA (N-nitrosodimethamine) treated and Ov+NDMA treated groups, and animals from each group were euthanized at 1, 3 and 6 months post-treatment. CCA-CA was not detected in normal biliary cells of non-treated hamsters throughout the course of experiment. CCA-CA became detectable in the cytoplasm and apical surface of biliary cells of the NDMA and Ov+NDMA groups at early stage (1 month) of tumor development and increased with tumor progression. In contrast, CCA-CA was detected as nuclear staining at the 1 month post Ov infection and declined thereafter. These results suggest the possibility of CCA-CA as an early marker for CCA.

[Continuous blood coagulation in chronic opisthorchiasis].

Animal experiments have shown that chronic Opisthorchis invasion results in accelerated continuous blood coagulation, by inducing hypercoagulation and platelet activation. The state of hemostasis depends on the degree of infection and undergoes the largest changes during maximum invasion. Irrespective of invasion rates, chronic opisthorchiasis is accompanied by hypofibrinogenemia.

[The efficiency of the enzyme immunoassay test system opisthorchiasis-CIC-EIA-best to detect circulating immune complexes containing opisthorchis antigens in the serum of patients with opisthorchiasis].

The efficacy of a kit of Opisthorchiasis-CIC-EIA-Best reagents was evaluated using 270 sera from patients in the study and control groups. The kit showed a sufficient sensitivity (not less than 87.2%) and a high specificity (not less than 97.9%). The use of the above kit of the reagents for enzyme immunoassay in practical healthcare enables one to increase detection rates among the infested subjects on comprehensive examination of those with suspected opisthorchiasis.