Western blot applied to the diagnosis and post-treatment monitoring of human hydatidosis

A rare and challenging case of intrapericardial hydatidosis

BACKGROUND

Hydatid cysts are most frequently located in the liver and lungs and very rarely can be found in the pericardium. Diagnosis and treatment are quite challenging, as the disease can present itself in many forms depending to the location and the complications that it might cause.

CASE PRESENTATION

A 22-year-old man presented to our hospital with ongoing dry cough for more than 1 month prior to admission. Other symptoms included chest pain, fatigue, low grade fever, and night sweats, which have worsened in the past 2 weeks. Physical examination revealed normal respiratory and heart function. Chest X-ray demonstrated mediastinal enlargement and left pleural effusion. Contrast-enhanced computed tomography images showed a walled cystic mass lesion measuring up to 56 × 50 mm in close proximity to the upper left atrium, ascending aorta and pulmonary artery, potentially localized in the pericardium, with a 10 mm endoatrial filling defect, findings were compatible with hydatid cyst, left pleural effusion and peripheral pulmonary upper left lobe consolidation. Cardiac involvement was excluded on magnetic resonance imaging and trans-esophageal ultrasound. The patient underwent fine needle aspiration of the affected lung and thoracocentesis. No malignancy was found, meanwhile the biopsy confirmed the presence of pulmonary infarction. In view of the imaging findings were highly suspicious of a hydatid cyst, we performed a test of antibody titers that was negative. The patient underwent left anterolateral thoracotomy, and after the opening of the pericardium, a cystic mass of 5 cm in diameter was found next to the left atrium and in close proximity with the left pulmonary veins. The content of the cyst was completely removed after the surgical area was isolated with gauze impregnated with hypertonic solution (NaCl 10%). The mass resulted to be an echinococcal cyst with multiple daughter cysts within it that did not penetrate/involve (perforate) the cardiac wall.

CONCLUSION

Pericardial echinococcosis is a very rare pathology in which a high expertise multidisciplinary approach is required. The compression mass effect caused by the cyst can lead to complications, such as in our case where the pulmonary vein was compressed, leading to pulmonary infarction. The value of radiology studies and transoesophageal ultrasound are very important in the diagnosis. Surgery in these cases is always recommended, but preferred surgical approach is questionable. In cases such as ours, we recommend anterolateral thoracotomy.

A Novel Designed Sandwich ELISA for the Detection of Echinococcus granulosus Antigen in Camels for Diagnosis of Cystic Echinococcosis

Echinococcus spp. are important cosmopolitan zoonotic parasitic tapeworms that cause a disease called hydatidosis or cystic echinococcosis (CE), which has remarkable economic losses. The objective of our study was to develop a specific IgG polyclonal antigen-based ELISA (Sandwich ELISA; capture ELISA) method for the detection of circulating Echinococcus granulosus (E. granulosus) antigens in camels infected with hydatid cysts before slaughtering and its application in serodiagnosis of CE in animals to assess the positive rate of hydatidosis in camels slaughtered in Giza governorate abattoirs in Egypt. In this study, molecular identification of Echinococcus sp. isolate was performed based on the NADH dehydrogenase subunit 1 (NAD1) gene, revealing the isolate (GenBank: OQ443068.1), which is identical to the G6 E. granulosus sensu lato genotype. The positive rate of hydatid cysts was determined in slaughtered camels' organs (n = 587). The results revealed that hydatid cysts were found in 46.5% (273/587) of the examined camels. Pulmonary echinococcosis was significantly more prevalent in the slaughtered camels (60%, 164/273) than hepatic echinococcosis (39.9%, 109/273), (p = 0.001, Chi Square = 11.081). Cyst fertility rates were higher in hepatic (90.8%, 99/109) than in pulmonary cysts (83.5%, 137/164) and the most viable protoscoleces were recorded from fertile the hepatic cysts (67.85 ± 12.78). In this study, hydatid cyst germinal layer antigen (GlAg) was isolated and used for the immunization of rabbits to raise IgG polyclonal antibodies (anti-Echinococcus GlAb IgG). These IgG polyclonal antibodies were purified by affinity chromatography using a protein A column, then labeled with horseradish peroxidase. Electrophoretic analysis of IgG polyclonal antibodies and crude GlAg was performed in 10% polyacrylamide gels. The SDS-PAGE revealed four bands at molecular weights of 77 kDa, 65 kDa, 55 kDa, and 25 kDa. The Sandwich ELISA was performed to evaluate the sensitivity and specificity and cross-reactivity of the prepared IgG polyclonal antibodies. The circulating hydatid antigen was found in 270 out of the 273 samples with hydatidosis, with a sensitivity of 98.9% (270/273), a specificity of 94.9% (296/312) and a diagnostic efficacy of 96.8%. Regarding the cross reactivity, anti-Echinococcus GlAb IgG showed a low cross-reactivity with Fasciola gigantica infected camel sera (3/8), and Myiasis (Cephalopina titillator larvae; 3/20). No cross-reactivity was recorded with uninfected camel sera (negative sera for E. granulosus), and no cross-reactivity was found with antigens of Eimeria spp., Toxoplasma gondii, Cryptosporidium sp., and Hyalomma dromedarii (ticks' infestation). Then, Sandwich ELISA was conducted again to detect E. granulosus antigen in all the collected camel sera, which resulted in a 48.7% (286/587) positive rate of CE compared to 46.5% (273/587) using a postmortem inspection (PM diagnosis) (p = 0.5, Chi Square = 0.302). In conclusion, the Sandwich ELISA technique introduced in this study appears to be a sufficiently sensitive diagnostic assay for the detection of camels' echinococcosis using anti-Echinococcus GlAb IgG. In addition, it might offer a significant medical and veterinary importance in helping the early detection of hydatidosis, as well as its early treatment.

Detection of Echinococcus granulosus sensu lato cysts and seroprevalence of cystic echinococcosis in cattle and camels in Maiduguri Abattoir

Cystic echinococcosis (CE) is a zoonotic disease of great importance worldwide. This study was conducted to determine the prevalence and antigenic profile of Echinococcus cysts (CE cysts) in camels and cattle. The lungs, livers, hearts, and kidneys of 560 animals, comprising 304 camels and 256 cattle slaughtered in the Maiduguri abattoir, were examined for CE. Blood samples were collected for serology. Protein profiles of CE fluids were analyzed using indirect Enzyme Linked Immunosorbent Assay while Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) was used to characterize the electrophoretic pattern of different CE cyst fluid samples. The overall prevalence of CE was 8.4%, 14.14% (95% CI = 10.65-18.54%) in camels and 1.60% (95% CI = 0.46-4.09%) in cattle. Adult camels 41 (16.21%) (95% CI = 12.15-21.27%) had a higher prevalence than the young camels 2 (3.92%) (95% CI = 0.33-13.97%) (p = 0.038). In cattle, only adults 4 (2.0%) had cysts. Higher prevalence of CE was recorded in male 22 (16.42%) (95% CI = 11.03-23.68%) than female 21 (12.35%) (95% CI = 8.16-18.21%) camels [p = 0.399] while only female cattle 3 (2.2%) had cysts. Higher prevalence of CE was recorded in the livers of 34 (11.18%) (95% CI = 8.08-15.25%) than in the lungs 25 (8.22%) (95% CI = 5.59-11.90%) of camels [p = 0.273]. Of the 47 cysts collected, 43 (91.49%) and 4 (8.51%) were from camels and cattle, respectively. A total of 18 (38.30%) fertile, 17 (36.17%) non-fertile, and 12 (25.53%) calcified cysts were recovered in animals. Overall seroprevalence of 52.63% (95% CI = 47.02-58.18%) and 35.55% (95% CI = 29.93-41.59%) were observed in camels and cattle in this study. The SDS-PAGE of camel CE cyst fluids revealed protein bands at 64kda, 91kda, 160kda, and 200kda molecular units while the purified cyst fluids revealed bands at 64kda, 91kda, 120kda, 160kda, and 200kda. Regular meat inspections and the exclusion of dogs from abattoir premises are strongly encouraged. Investigation into local prevailing factors encouraging transmission should be carried out.

Sero-epidemiology of Hydatidosis Among General Population of Jolfa County, Northwestern Iran Using IHA, ELISA and Western Blot (2017-2018)

BACKGROUND

Human hydatidosis is mostly a latent and neglected disease with known endemicity in Iran.

AIMS

Due to the importance of this infection in the country and its latent nature, we aimed to evaluate the serological status of hydatid cyst in northwestern Iran.

OBJECTIVES

Herein, we evaluated the serological status of hydatid cyst in urban and rural inhabitants of Jolfa county, northwestern Iran during 2017-2018.

METHODS

In total, 1296 blood samples were obtained from human individuals and the presence of anti-E. granulosus antibodies was investigated using IHA, ELISA and WB.

RESULTS

Based on results, 25 IHA positive person were detected in the examined population, however ELISA test showed 14 of 25 IHA positive patients as negative. Also, 269 IHA negative fellows were shown as negative by ELISA. WB analysis of sera from 25 IHA positive subjects revealed consistent results with the ELISA test, and the most reactive SHCF Ag was a 37 KDa protein. The age-standardized seroprevalence of hydatidosis among Jolfa's general population was 1.12% with 95%CI: 1.02-1.20. Moreover, there existed a significant association between keeping/- contact with dogs (P = 0.022) as well as vegetable consumption (P < 0.001) with ELISA positive test results.

CONCLUSION

Along with such serological evidence in this region, we highly suggest physical examination and applying imaging techniques for suspected cases in the area for a better understanding of CE.

Cordyceps sinensis promotes immune regulation and enhances bacteriostatic activity of PA-824 via IL-10 in Mycobacterium tuberculosis disease

PA-824 is a novel bicyclic nitroimidazole anti-tuberculosis (TB) drug. Cordyceps sinensis (Berk.) Sacc. (CS) was proven to be a good immunomodulatory compound. This research aimed to investigate the effect of CS on PA-824 in Mycobacterium tuberculosis (M.tb) infected mice (female CBA/J mice, 6 to 8 weeks of age and 20±2 g of weight). Mice were randomly assigned to 4 groups: PA-824, CS, PA-824+CS, and control. To verify the effect of PA-824 and CS on M.tb, after drug administration, mice lungs were harvested and bacterial colony formations were measured. Cells were isolated from infected lungs and spleens to analyze the percentage of CD4⁺ T cells (CD11a positive). Lung cells were cultured to detect the secretion of interferon-γ (IFN-γ) and interleukin-10 (IL-10) by ELISA. IFN-γ and IL-10 double-positive CD4⁺ cells in peripheral blood were measured by flow cytometry. The expression levels of IL-2 and IL-10 in mice lungs were analyzed by real-time PCR and western blot. Results showed that PA-824 combined with CS led to the lowest lung colony-forming units (CFU) counts among treated groups. Furthermore, this beneficial outcome might be associated with the decreased CD11a on CD4⁺ cells in mice lungs and spleens. Moreover, the suppressed secretion of IFN-γ and IL-10, and IL-10 expressions, as well as the decreased IFN-γ and IL-10 double-positive CD4⁺ cells in blood, could also be associated with the positive effect. However, no significant effect on IL-2 production was found. The combination of PA-824 and CS had more effective bacteriostatic and immunomodulatory effects on M.tb infected mice than PA-824 alone. In conclusion, CS has the potential to be an effective adjuvant in TB treatment.

Laboratory Diagnosis of Echinococcus spp. in Human Patients and Infected Animals

Among the species composing the genus Echinococcus, four species are of human clinical interest. The most prevalent species are Echinococcus granulosus and Echinococcus multilocularis, followed by Echinococcus vogeli and Echinococcus oligarthrus. The first two species cause cystic echinococcosis (CE) and alveolar echinococcosis (AE) respectively. Both diseases have a complex clinical management, in which laboratory diagnosis could be an adjunctive to the imaging techniques. To date, several approaches have been described for the laboratory diagnosis and followup of CE and AE, including antibody, antigen and cytokine detection. All of these approaches are far from being optimal as adjunctive diagnosis particularly for CE, since they do not reach enough sensitivity and/or specificity. A combination of several methods (e.g., antibody and antigen detection) or of several (recombinant) antigens could improve the performance of the adjunctive laboratory methods, although the complexity of echinococcosis and heterogeneity of clinical cases make necessary a deep understanding of the host-parasite relationships and the parasite phenotype at different developmental stages to reach the best diagnostic tool and to make it accepted in clinical practice. Standardization approaches and a deep understanding of the performance of each of the available antigens in the diagnosis of echinococcosis for the different clinical pictures are also needed. The detection of the parasite in definitive hosts is also reviewed in this chapter. Finally, the different methods for the detection of parasite DNA in different analytes and matrices are also reviewed.

Immunological diagnosis of human hydatid cyst using Western immunoblotting technique

BACKGROUND

Echinococcosis is a parasitic disease with worldwide distribution which is caused by the tapeworms Echinococcus granulosus. Diagnosis of the disease relies on imaging techniques, but the techniques are not able to differentiate the cyst from benign or malignant tumors; hence, appropriate serologic methods are required for the differential diagnosis of the infection.

MATERIALS AND METHODS

In this investigation, different sheep hydatid cyst antigens probed with thirty sera of patients with hydatid cyst and also thirty human normal sera using Western immunoblotting technique. Considering results of surgery as gold standard, sensitivity and specificity of Western blotting was estimated.

RESULTS

Sera of 29, 26, and 16 patients with hydatid cyst reacted with specific bands of hydatid cyst fluid (HCF), protoscolex crude antigen, and cyst wall crude antigen, respectively. However, none of the normal human sera reacted with those specific bands.

CONCLUSION

A 20 kDa band of sheep HCF is an appropriate antigen for serodiagnosis of hydatid cyst infection.

Anti-IgG-anchored liquid crystal microdroplets for label free detection of IgG

AIgG anchored LC microdroplets showing configurational transition from radial (a) to bipolar (b) upon interaction with IgG.

Sero-epidemiological survey of human cystic echinococcosis in Kashmir, North India

BACKGROUND

Echinococcosis is a human and animal health problem in many endemic areas worldwide. There are numerous reports and hospital-based studies from Kashmir, North India, yet there has been no epidemiological study conducted in Kashmir, the apparently endemic area for human hydatidosis. This study was designed to determine the seroprevalence of hydatid infection in Kashmir Valley and to find out association of risk factors for acquisition of this infection.

METHODOLOGY

Fourteen hundred and twenty-nine samples were collected from different districts in the Kashmir region (North India) using systematic random sampling. The 130 control samples included were from apparently healthy blood donors (100), patients with other parasitic infections (20), surgically confirmed hydatidosis patients (5), and apparently healthy subjects excluded for hydatidosis and intestinal parasitic infections (5). Hydatid-specific IgG antibody was detected by enzyme-linked immunosorbent assay, and seropositive samples were analysed further by Western blotting.

RESULTS

Out of 1,429 samples, 72 (5.03%) were IgG positive by ELISA. The percentage occurrence of the highly immunoreactive antigenic fractions in IgG ELISA positive samples was 57 kDa (72.2%) followed by 70 kDa (66.7%) and 39 kDa (58.3%) by immunoblotting. Samples with other parasitic infections were reactive with the cluster of 54-59 kDa antigenic fractions. Age <15 years, male gender, contact with dog, and rural residence were the most significant factors associated with the seropositivity.

CONCLUSION

The study revealed that 72 (5.03%) out of 1,429 subjects asymptomatic for hydatidosis were seropositve to E.granulosus antigen by ELISA. Western blot analysis of 72 ELISA seropositive samples showed that 66.7% and 58.3% of samples were immunoreactive with 70 and 39 kDa specific antigenic fractions, respectively. The seropositivity was significantly higher (5.79%) in the younger age group (<15 years) as compared to the 16-55 years (4.07%) and > 55 years (3.05%) age groups, suggesting ongoing transmission of this infection in the younger age group. The number of seropositive males was significantly higher as compared to females. The risk factors identified were rural residence and contact with dogs. The study suggests the presence of asymptomatic infection in subjects in Kashmir, North India, and efforts need to be made for implementation of effective prevention measures to reduce the infection burden, which may otherwise lead to symptomatology and complications in the infected subjects.

Clinical characterization of unusual cystic echinococcosis in southern part of Turkey

BACKGROUND AND OBJECTIVES

The incidence of primary extrahepatic cystic echinococcosis (CE) is rare. Generally, radiological and serological findings can help establish the diagnosis of hepatic and pulmonary CE, but a CE in an unusual location with atypical radiological findings may complicate the differential diagnosis. The objective of this study is to present the characteristics of cases with extrahepatic CE in respect of sites of involvement, clinical presentations, radiological findings, serological diagnostic evaluations, and outcomes of infected patients.

DESIGN AND SETTINGS

A retrospective analysis of surgically treated CE was conducted between January 1993 and January 2014 in the General Surgery, Pediatric Surgery, Urology, Cardiovascular Surgery, Neurosurgery, and Orthopedics departments of University of Cukurova, Faculty of Medicine, Balcal Hospital.

PATIENTS AND METHODS

Among the 661 patients managed for CE, 134 had unusual sites of involvement. Radiological and serological examinations were used to differentiate CE from alveolar echinococcosis.

RESULTS

Of 134 cases with unusual sites of involvement, 32 cases had liver CE (23.9%), 7 cases had lung CE (5.2%), and 2 cases had concomitant liver and lung CE (1.5%). In 93 (69.4%) cases, unusual organ involvement was isolated without any liver or lung involvement. The mean age was 45 years. Abdominal pain was the main symptom and was found in 104 patients. Thirty-one (23.1%) of 134 extrahepatic CE cases were evaluated as negative with indirect hemagglutination (IHA). However, positive results were obtained in 54 cases evaluated with Echinococcus granulosus IgG Western blot (WB), including 10 IHA-negative cases.

CONCLUSION

CE with unusual localizations may cause serious problems of diagnostic confusion. The combination of clinical history, radiological findings, and serological test results (especially the WB) are valuable in diagnosing extrahepatic CE.

Primary hydatid cyst in the adrenal gland

An elderly man presented with a 2-year history of refractory hypertension. His medical history, physical examination and laboratory findings were unremarkable. On subsequent ultrasound study for the evaluation of renal artery stenosis, a large mass obliterating the adrenal gland containing internal cystic structures was identified. A CT study confirmed the diagnosis of primary adrenal gland hydatid cyst. Following surgical resection, the patient's hypertension resolved and medications to control blood pressure were discontinued.

Evaluation of purified 27.5 kDa protoscolex antigen-based ELISA for the detection of circulating antigens and antibodies in sheep and human hydatidosis

Hydatidosis is a zoonotic disease caused by the larval stage of Echinococcus granulosus, and the diagnosis of hydatidosis to date remains unresolved despite the development of many serological techniques. The present study aimed to develop an antigen-based enzyme-linked immunosorbent assay (ELISA) using IgG anti-27.5 kDa protoscolex antigen (27.5 PA) for measuring circulating protoscolex antigen (CPA), for comparison with an antibody detection assay, in sera of naturally infected sheep and humans in highly endemic areas in Egypt. In sheep, the sensitivity of ELISA in detecting anti-27.5 PA IgG and CPA was 75.0 and 60.0%, respectively, and the recorded specificity was 80.0 and 88.0%, respectively. In humans, the sensitivity of ELISA in detecting anti-27.5 PA IgG and CPA was 62.5 and 52.5%, respectively, while the specificity of the assay was 66.7 and 75.0%, respectively. In conclusion, an antibody detection assay is still superior and is more sensitive than an antigen detection assay, especially in diagnosing an active infection in which hydatid cysts are predominant. An antigen detection assay may be a useful approach to assessment of the efficacy of treatment, especially after removal of the cyst. Further studies are recommended to improve the diagnostic efficacy of an antigen-based ELISA method by using a highly purified recombinant antigen.

Recombinant AgB8/1 ELISA test vs. commercially available IgG ELISA test in the diagnosis of cystic echinococcosis

The diagnosis and clinical management of cystic echinococcosis (CE) rely on imaging and serology, the latter still having a complementary role as its accuracy in assessing cyst viability is unsatisfactory. We used an experimental IgG ELISA test based on the recombinant antigen rEgAgB8/1 cloned from Echinococcus granulosus to differentiate active from inactive/cured CE infection, comparing its performance to that of a commercially available ELISA test used routinely in our hospital laboratory. Both tests were performed on sera from 88 patients with hepatic echinococcal cysts, grouped according to cyst stage based on ultrasonographical morphology, and on 17 patients surgically treated for echinococcosis and 18 patients with nonparasitic hepatic cysts included as controls. Tests' performances did not differ significantly, but the overall concordance between tests drastically dropped when groups were analysed separately. Further longitudinal studies should evaluate whether these discrepancies reflect the different ability of either test to predict the evolution of cysts over time. Although the recombinant-AgB8/1-based ELISA test seems to have no clinical advantage over the commercially available ELISA test in the assessment of hepatic CE cyst viability, the easiness of production and reproducibility of high-quality recombinant antigens makes rEgAgB8/1 a valid candidate for use in CE ELISA diagnostic tests.

Immunoblotting with human native antigen shows stage-related sensitivity in the serodiagnosis of hepatic cystic echinococcosis

The diagnosis of hepatic cystic echinococcosis is based on ultrasonography and confirmed by serology. However, no biological marker of cyst viability is currently available implying years-long patient follow-up, which is not always feasible in endemic areas. We characterized the performance of an immunoblotting test based on human hydatid cyst fluid with particular regard to its ability to distinguish between cyst stages. Sera from patients with cysts in different stages showed distinctive band pattern recognition. Most importantly, the test discriminated in 80% of cases CE3a from CE3b transitional cysts, known to have different viability profiles. Interestingly, we observed a rapid change in band pattern recognition of sera from one patient at time points when his cyst passed from active to transitional to inactive stages. Further identification of different antigens expressed by different cyst stages will support the development of diagnostic tools that could early define cyst viability, to guide clinical decision making, and shorten patient follow-up.

A mass screening survey of cystic echinococcosis by ultrasonography, Western blotting, and ELISA among university students in Manisa, Turkey

Cystic echinococcosis (CE) is one of the most important zoonotic diseases in a wide geographic area, including Turkey. In the present project, a total of 4275 students from Celal Bayar University, Manisa, Turkey, were screened by ultrasonography (US) and specific antibodies for CE were examined by Western blotting (WB) and ELISA in finger prick blood samples of 2034 of 4275 volunteered students. We aimed to report the apparent prevalence of CE based on different diagnostic procedures and to compare WB and ELISA with US in diagnosis of CE in a mass screening setting. Six new cases were diagnosed as CE by US during the survey. In addition to these cases, three students were also detected to have been previously operated and pathologically confirmed for hepatic CE. US revealed parenchymal changes in these cases in concordance with their operation history; so, the prevalence of CE by US was calculated as 0.21% (9/4275) (95%CI, 0.11-0.39%) among university students in Manisa. Bands were detected at 8, 28, 32, 38, 42, 47, 70 and 90kDa by WB and the cases were considered to be positive for CE when at least three of the bands were seen together. Apparent prevalence of CE by ELISA and WB were found to be 2.11% (43/2034) (95%CI, 1.57-2.83%) and 0.25% (5/2034) (95%CI, 0.10-0.57%), respectively. Of the six US positive cases, WB was positive in only one case with two cysts in the liver. All of four cases with liver involvement were positive by ELISA. The high prevalence of CE among university students in Manisa indicated that CE is a major health problem in this area of Turkey. Our results supported that WB is rather difficult and not feasible as a mass screening test and may not be effective for confirmation especially in asymptomatic cases. As a result, we recommend US to be used initially in mass screening surveys for CE followed by confirmation by ELISA for suspected cases. Further examination primarily by chest X-ray followed by computed tomography and/or magnetic resonance imaging, if needed, should be recommended for US negative, ELISA and WB positive individuals who may have non-abdominal cysts.

Giant primary adrenal hydatid cyst presenting with arterial hypertension: a case report and review of the literature

Introduction

A primary hydatid cyst of the adrenal gland is still an exceptional localization. The adrenal gland is an uncommon site even in Morocco, where echinococcal disease is endemic.

Case presentation

We report the case of a 64-year-old Moroccan man who presented with the unusual symptom of arterial hypertension associated with left flank pain. Computed tomography showed a cystic mass of his left adrenal gland with daughter cysts filing the lesion (Type III). Despite his negative serology tests, the diagnosis of a hydatid cyst was confirmed on surgical examination. Our patient underwent surgical excision of his left adrenal gland with normalization of blood pressure. No recurrence has occurred after 36 months of follow-up.

Conclusion

There are two remarkable characteristics of this case report; the first is the unusual location of the cyst, the second is the association of an adrenal hydatid cyst with arterial hypertension, which has rarely been reported in the literature.

Serum antigen and antibody detection in echinococcosis: application in serodiagnosis of human hydatidosis

Diagnosis of hydatidosis is based on immunodiagnostic methods along with radiological and ultrasound examinations. The objectives of the present study were to develop a specific and simple antigen-based ELISA method for diagnosis of hydatidosis and compare it with antibody detection method. The subjects in this study included 89 patients in the following groups: surgically confirmed hydatidosis patients (35 cases), control with other parasitic diseases (29 cases), and healthy controls (25 cases). Hyperimmune serum was raised against hydatid cyst fluid in rabbits. Anti-hydatid cyst IgG was purified by affinity chromatography using protein A column and labeled with horseradish peroxidase. Collected sera were assessed for hydatid cyst antigens and antibody by ELISA. Circulating hydatid antigen was found in 9 out of 35 patients with surgically confirmed hydatidosis. A sensitivity of 25.7% and a specificity of 98.0% were calculated for the antigen detection assay. Antibody detection by indirect ELISA, using antigen B, showed that 94.2% of patients (33 cases) have anti-hydatid cyst antibodies in their serum while cross reaction was noted in a few of non-hydatidosis patients. A sensitivity of 94.2% and specificity of 81.6% were found for the antibody detection assay. Findings of this study indicated that antibody detection assay is a sensitive approach for diagnosis of hydatid cyst while antigen detection assay might be a useful approach for assessment of the efficacy of treatment especially after removal of the cyst.

Assessment of Echinococcus granulosus somatic protoscolex antigens for serological follow-up of young patients surgically treated for cystic echinococcosis

Echinococcus granulosus protoscolex soluble somatic antigens (PSSAs) were assessed for their prognostic value in the serological follow-up of young patients treated for cystic echinococcosis (CE), compared to conventional hydatid fluid (HF) antigen. Based on different clinical courses and outcome of infection, as well as imaging findings, patients were retrospectively classified into two different groups including either cured CE (CCE; i.e., absence of active cysts or presence of inactive cysts, respectively) and noncured CE (NCCE) patients still presenting active cysts at the end of an up to 5-year follow-up period. An immunoglobulin G (IgG)-PSSA enzyme-linked immunosorbent assay (ELISA) showed a gradual decrease in antibody levels in CCE cases, reaching seronegativity in 20% of the cases at least within 5 years postsurgery. In comparison, the conventional IgG-HF ELISA showed a significantly lower progressive decrease in antibody levels, serology becoming negative in only 15% of CCE patients at the endpoint of the follow-up period. Serological analysis of PSSA by immunoblotting yielded an interesting immunoreactive double band of 27 and 28 kDa that, in 15 (75%) of 20 CCE cases, exhibited a rapid decrease and subsequent disappearance of respective antibody reactivities within 3 years postsurgery. Conversely, anti-27- and -28-kDa antibody reactivity strongly persisted until the endpoint of the follow-up period in all of the five NCCE patients. Further analysis of the 27- and 28-kDa doublet by using affinity-purified antibodies showed that the double band was not detectable in HF. Furthermore, a predominantly IgG4 subclass-restricted humoral immune response against the 27- and 28-kDa antigens was demonstrated in seroreactive CE patients. Overall, an anti-27- and -28-kDa response appeared to correlate with cyst activity. In conclusion, PSSA represents a useful candidate to carry out a serologic follow-up of CE subsequent to treatment and deserves further respective evaluation for other age groups of CE patients.

Post-surgical follow-up (by ELISA and immunoblotting) of cured versus non-cured cystic echinococcosis in young patients

The study was designed to determine comparatively the prognostic value of immunoblotting and ELISA in the serological follow-up of young cystic echinococcosis (CE) patients exhibiting either a cured or a progredient (non-cured) course of disease after treatment. A total of 54 patients (mean age 9 years, range from 3 to 15 years) with surgically, radiologically and/or histologically proven CE were studied for a period up to 60 months after surgery. Additionally, some of the patients underwent chemotherapy. Based on the clinical course and outcome, as well as on imaging findings, patients were clustered into 2 groups of either cured (CCE), or non-cured (NCCE) CE patients. ELISA showed a high rate of seropositivity 4 to 5 years post-surgery for both CCE (57.1%) and NCCE (100%) patients, the difference found between the two groups was statistically not significant. Immunoblotting based upon recognition of AgB subcomponents (8 and 16 kDa bands) showed a decrease of respective antibody reactivities after 4 years post-surgery. Only sera from 14.3% of CCE patients recognized the subcomponents of AgB after 4 years, while none (0%) of these sera was still reactive at 5 years post-surgery. At variance, immunoblotting remained positive for AgB subcomponents in 100% of the NCCE cases as tested between 4 and 5 years after surgical treatment. Immunoblotting therefore proved to be a useful approach for monitoring post-surgical follow-ups of human CCE and NCCE in young patients when based upon the recognition of AgB subcomponents.

Improved serodiagnosis of alveolar echinococcosis of humans using an in vitro-produced Echinococcus multilocularis antigen

Serology is an important tool for the diagnosis of alveolar echinococcosis (AE) in humans. In order to improve serodiagnostic performance, we have developed an in vitro-produced Echinococcus mulilocularis metacestode vesicle fluid (EmVF) antigen for application in an immunoblot assay. Immunoblot analysis of EmVF revealed an abundant immunoreactive band triplet of 20-22 kDa, achieving a sensitivity of 100% based on the testing of sera from 62 pre-operative and pre-treatment cases of active and inactive AE. Thus, the EmVF-immunoblotting allowed the specific detection of cases seronegative by the Em2- and/or EmII/3-10-ELISA, usually attributable to abortive, inactive cases of AE. The specificity of the EmVF-immunoblotting did not allow discrimination between AE and cystic echinococcosis (CE) but was 100% with respect to non-Echinococcus parasitic infections or cancer malignancies. Based on the findings of this study, it is recommended that the current ELISA test combination (Em2- and II/3-10-ELISA) be complemented with EmVF-immunoblotting, allowing an improved diagnosis of both clinical and subclinical forms of AE, including those associated with E. multilocularis-specific antibody reactivities not detectable by ELISA.

Percutaneous imaging-guided treatment of hydatid liver cysts: Do long-term results make it a first choice?

AIM

To evaluate the long-term results of percutaneous imaging-guided treatment of hydatid liver cysts.

MATERIALS AND METHODS

Sixty patients with 77 hydatid liver cysts underwent percutaneous treatment with ultrasonography (US) or computed tomography (CT) guidance. Absolute alcohol and hypertonic saline were used for sclerosing the cysts after aspiration. Prophylactic albendazole treatment was given before and after the procedures. Follow-up US and CT were obtained periodically, and changes in cyst morphology were recorded. Minimum follow-up period for the patients included in this study was 12 months. Serological correlation was also available for a group of patients. The outcome of the procedures were categorized into five groups based on morphological changes observed by imaging.

RESULTS

Procedures were regarded as successful in 80% and unsuccessful in 20% of patients. Failures most often occurred with type III cysts; less than half (39%) of the total type III cysts had a successful outcome. On the other hand, all type I cysts ended up with cure. Anaphylaxis, pneumotorax and severe pain interrupting the procedures were also among the reasons of failure.

CONCLUSION

Percutaneous aspiration, injection and reaspiration (PAIR) of types I and II hydatid liver cysts is effective and safe in the long-term. Surgery should no longer be regarded as the first choice treatment in all hydatid liver cysts but should be reserved for type III and certain active type IV cysts.

Repeated treatment of cystic echinococcosis in patients with a long-term immunological response after successful surgical cyst removal

Six cystic echinococcosis patients underwent surgery for the removal of echinococcal cysts. All were treated with albendazole prior to and following treatment. After surgery, no cysts were detected in five of the six patients examined. Both ELISA and immunoblot analysis have been used to determine specific IgG, IgG4 and IgE activities. Total elimination of IgG and IgG4 was not achieved in any of the patients studied. Prior to the first surgery/treatment, specific IgG, IgG4 and IgE antibodies were demonstrated in all patients, except one who did not show any IgE activity. The first treatment was followed by highly elevated IgE in two patients; in one of them it was further combined with an apparent decrease in IgG activity. Repeated treatment with albendazole given 0.8-8.5 years after the first treatment/surgery was followed by either moderate or highly reduced IgE activity in two patients, respectively, and a slight increase in IgG4 in another patient. A third course of treatment, given 2-2.5 years after the second treatment, barely affected the antibody activities. The present study suggests that anti-echinoccocal antibody activity may remain high many years after successful cyst removal. Determination of IgG, IgG4 and IgE responses is preferable for the assessment of treatment results. The presence of anti-echinococcal antibodies after surgery with no cyst detection does not necessarily indicate an active echinococcal infection.

Evaluation of enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunoelectrotransfer blot (EITB) for immunodiagnosis of hydatid diseases in sheep

This study was undertaken to investigate antigenic characteristics of hydatid cyst fluid in sheep by SDS-PAGE method, to evaluate sensitivity and specificity of Enzyme-linked immunosorbent assay (ELISA) and Enzyme-linked immunoelectrotransfer blot (EITB) assay for diagnosis of sheep hydatidosis, and to determine seroprevalance of hydatidosis in sheep population in Elazig, Turkey. SDS-PAGE analysis of hydatid cyst fluids indicated that 6 specific-protein bands were detected at molecular weights of 29, 45, 58, 68, 98 and 116 kDa. EITB analysis showed presence of 29, 38, 42, 58, 62, 68, 98, 116, 120, 150 and 205 kDa bands in positive sheep sera, while 38, 58, 62, 68, 116 and 205 kDa bands were detected in negative sheep sera. Therefore, it was concluded that the 116 kDa band was specific for diagnosis of sheep hydatid disease by EITB assay. Sensitivity and specificity of EITB assay were determined as 88% and 84%, respectively, whereas corresponding rates for ELISA were 60% and 94%, respectively. Sensitivity of ELISA was 47.3% in hepatic cysts, 60% in pulmonary cysts, 69.2% in hepato-pulmonar cysts. Sensitivity ratios of ELISA were 67.8%, 75%, and 38.4% for fertile, sterile, and under-growth cysts, respectively. Sensitivity of EITB was found 84.2% in hepatic cysts, 80% in pulmonary cysts, and 92.3% in hepato-pulmonar cysts. Corresponding ratios for sensitivity of EITB for fertile, sterile, calcified, and under growth cysts were 92.8%, 75%, 100%, and 84.6%, respectively. In addition, seroprevalance of hydatidosis in sheep was found as 62% by ELISA and 66.4% by EITB in Elazig, Turkey and seroprevalance increased by age.

Development of a dipstick dye immunoassay for diagnosing hydatidosis

We have developed a kit to diagnose hydatidosis, based on the detection of specific antibodies. This disease, caused by larvae of the cestode Echinococcus granulosus, is a zoonosis commonly found throughout the world. The diagnostic kit discriminates between positive and negative cases in a way that is easily interpreted, i.e., positive cases form a colored band on an inert substrate. The results show test sensitivity to be some 94.87% and specificity 85.71%, which is comparable to those of the ELISA technique. The high sensitivity and specificity of this test affords the great advantage of speed in diagnosing this parasitosis. No other equipment or procedure is required.