An update on immunodiagnosis of cystic echinococcosis

Ghrelin regulating liver activity and its potential effects on liver fibrosis and Echinococcosis

Ghrelin widely exists in the central nervous system and peripheral organs, and has biological activities such as maintaining energy homeostasis, regulating lipid metabolism, cell proliferation, immune response, gastrointestinal physiological activities, cognition, memory, circadian rhythm and reward effects. In many benign liver diseases, it may play a hepatoprotective role against steatosis, chronic inflammation, oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress and apoptosis, and improve liver cell autophagy and immune response to improve disease progression. However, the role of Ghrelin in liver Echinococcosis is currently unclear. This review systematically summarizes the molecular mechanisms by which Ghrelin regulates liver growth metabolism, immune-inflammation, fibrogenesis, proliferation and apoptosis, as well as its protective effects in liver fibrosis diseases, and further proposes the role of Ghrelin in liver Echinococcosis infection. During the infectious process, it may promote the parasitism and survival of parasites on the host by improving the immune-inflammatory microenvironment and fibrosis state, thereby accelerating disease progression. However, there is currently a lack of targeted in vitro and in vivo experimental evidence for this viewpoint.

A Canadian children's hospital's experience with cystic echinococcosis over 30 years: A case series

Background

Cystic echinococcosis (CE) or hydatid disease caused by the cestode Echinococcus granulosus sensu lato is an uncommon infection in Canada especially among children. There are limited reports describing the clinical presentation and management in Canadian children.

Methods

The medical records of all children diagnosed with CE at a quaternary paediatric centre in Ontario between January 1988 and August 2021 were retrospectively reviewed. The clinical course, management, and outcomes of each case were summarized.

Results

We report two paediatric cases of cystic echinococcosis (CE) in detail and review four additional cases seen at our institution over 33.5 years. The first case was a previously healthy 12-year-old boy with pulmonary CE resulting in unilateral lung collapse and mediastinal shift, who was presumedly infected while living in the Middle East. The second case was a previously healthy 3-year-old girl with pulmonary CE acquired locally in southern Ontario. Four other cases of CE with hepatic involvement (median age 12.5 years) were identified during the study period. Five out of six patients received both surgical and medical therapy.

Conclusion

CE is a rare but serious disease seen in southern Canada that has historically been associated with travel or migration. Due to changes in urban wildlife landscapes and increased global migration, CE may become more prevalent in Canadian children. We describe the first locally acquired case in rural southern Ontario diagnosed at our centre. Prompt recognition of this infection in children by health care providers is important to prevent morbidity and mortality.

Cystic echinococcosis of the bone

PURPOSE OF REVIEW

Cystic echinococcosis (CE) has a wide world distribution causing important morbidity. Osseous involvement is present in less than 4% of the CE cases. Its diagnosis and therapeutic management is full of challenges and low grade of evidence.

RECENT FINDINGS

The study summarizes literature evidence on the management of osseous CE with particular emphasis on new data regarding diagnosis and treatment.

SUMMARY

Clinical presentation of osseous CE depends on the skeletal area affected. Diagnosis is mostly based on radiological findings and serology. Recent advances with qPCR on osseous tissue samples seem to be a good option for diagnosis confirmation. Complete resection of the cystic lesion is the only curative option, but it is usually not possible performing palliative surgery and prolonged albendazole intake in most cases. Radiotherapy could be an option, but experience to date is only based on clinical cases.

Past and Present of Diagnosis of Echinococcosis: A Review (1999-2021)

The larval forms of taeniid cestodes belonging to the genus Echinococcus are the source of the zoonotic infection known as echinococcosis. Alveolar and cystic echinococcosis are caused by Echinococcus multilocularis and Echinococcus granulosus (s. s) respectively. It is endemic in several regions of the world. In this systematic review, we describe diagnosis, and the species (human, canids, livestock, and small rodents) affected by cystic (CE) and alveolar echinococcosis (AE). From 1999 to 2021, we searched the online directory through PubMed, SCOPUS, Web of Science, and google scholar. Among the 37,700 records found in the online databases, 187 publications met our eligibility requirements. The majority of investigations employed a range of diagnostic methods, such as ELISA, imaging, copro-PCR, necropsy or arecoline hydrobromide purgation, morphological cestode confirmation, and fecal sieving/flotation to detect and confirm Echinococcus infection. ELISA was the most commonly used method followed by PCR, and imaging. The research team retrieved data describing the incidence or assessment of the diagnostic test for E. multilocularis in humans (N = 99), canids (N = 63), small ruminants (N = 13), large ruminants (N= 3), camel (N= 2), pigs (N=2) and small mammals (N= 5). This study was conducted to explore the diagnostic tools applied to detect echinococcosis in humans as well as animals in prevalent countries, and to report the characteristic of new diagnostic tests for disease surveillance. This systematic review revealed that ELISA (alone or in combination) was the most common method used for disease diagnosis and diagnostic efficacy and prevalence rate increased when recombinant antigens were used. It is highly recommended to use combination protcols such as serological with molecular and imaging technique to diagnose disease. Our study identified scarcity of data of reporting echinococcosis in humans/ animals in low-income or developing countries particularly central Asian countries. Study reports in small rodents indicate their role in disease dissemination but real situation in these host is not refected due to limited number of studies. Even though echinococcosis affects both public health and the domestic animal sector, therefore, it is important to devise new and strengthe implementation of the existing monitoring, judging, and control measures in this estimate.

Immunogenicity of peptide-based vaccine composed of epitopes from Echinococcus granulosus rEg.P29

Echinococcus granulosus is one of the main causes of economic loss in the livestock industry because of its food-borne transmission. Cutting off the transmission route is a valid prevention method, and vaccines are the most effective means of controlling and eliminating infectious diseases. However, no human-related vaccine has been yet marketed. As a genetic engineering vaccine, recombinant protein P29 of E. granulosus (rEg.P29) could provide protection against deadly challenges. In this study, we generated peptide vaccines (rEg.P29_T , rEg.P29_B , and rEg.P29_T+B ) based on rEg.P29 and an immunized model was established by subcutaneous immunization. Further evaluation showed that peptide vaccine immunization in mice induced T helper type 1 (Th1)-mediated cellular immune responses, leading to high levels of rEg.P29 or rEg.P29_B -specific antibodies. In addition, rEg.P29_T+B immunization can induce a higher antibody and cytokine production level than single-epitope vaccines, and immune memory is also longer. Collectively, these results suggest that rEg.P29_T+B has the potential to be developed as an efficient subunit vaccine for use in areas where E. granulosus is endemic.

A recombinant rabies virus expressing Echinococcus granulosus EG95 induces protective immunity in mice

Cystic echinococcosis (CE), caused by Echinococcus granulosus (E, is a zoonosis with a worldwide distribution, resulting in heavy impact to public health and social economics. In this study, we generated a recombinant rabies virus (RABV) expressing EG95 protein of E. granulosus (LBNSE-EG95) as a bivalent candidate vaccine for use in sheep and cattle against CE and rabies, which is another severe health threat in CE-endemic areas. It was found that EG95 was successfully expressed without altering the pathogenicity of parent LBNSE vector. Further study showed that LBNSE-EG95 immunization in mice elicited activation of dendric cells (DCs) and B cells and induced Th1-/Th2-mediated cellular immune responses, leading to robust production of RABV neutralizing antibodies and high level of EG95-sepecific antibodies with more than 90% protection against CE. In addition, single dose of LBNSE-EG95 conferred full protection against lethal RABV challenge in mice. Collectively, these results suggest that the recombinant LBNSE-EG95 has the potential to be developed as an efficient bivalent vaccine for sheep and cattle use in endemic areas of CE and rabies.

Case Report: Laparoscopic Excision of a Primary Giant Splenic Hydatid Cyst: Literature Review

Cystic echinococcosis (CE), also known as hydatid cyst, is a zoonosis caused by the tapeworm Echinococcus granulosus. It is a common health problem in many countries. This condition predominantly affects the liver and the lungs, and the spleen to a less extent (splenic hydatid cyst, SHD). Indeed, it is estimated that SHD occurs in less than 2% of abdominal CE and 0.5-8% of CE cases. Here, we present a case of a 44-year-old Chinese woman with primary giant SHD who experienced pain in the left hypochondrium for 10 days. A combination of abdominal ultrasonography and computed tomography (CT) were used for preoperative diagnosis. Laparoscopic splenectomy was performed without any complications, and albendazole (400 mg per day) was administered postoperatively for 3 months. At 3-, 6-, 12-, and 24-month follow-up, the patient remained symptoms free, and abdominal CT found no signs of recurrence. In addition to this case, we review the previous literature on SHD treated by laparoscopy and reveal that laparoscopic approach is safe and effective for SHD. Particularly, we show that laparoscopic splenectomy is feasible for giant cysts (> 10 cm) at high risk of rupture or compressing other vital structures.

Potential role of NF-κB pathway in the immuno-inflammatory responses during human cystic echinococcosis

Cystic echinococcosis (CE) induces in the human host innate and adaptive immune response that plays an important role in controlling the immunopathogenesis. Due to the crucial role of nuclear factor kappa B (NF-κB) in regulating immuno-inflammatory processes, we investigated its potential contribution in systemic and local immuno-inflammatory responses in primary CE patients and relapsed patients. The expression of NF-κB and inducible nitric oxide synthase (iNOS) was analyzed in peripheral blood mononuclear cells (PBMC) as well as in pericystic layer of pulmonary hydatid cysts from Algerian primary CE patients and relapsed patients. Tumor necrosis factor alpha (TNF-α) and nitric oxide (NO) production was evaluated in plasma samples. Our results showed high iNOS and NF-κB expression in both PBMCs and pericystic histiocytes from primary CE patients. In addition, substantial amounts of systemic NO and TNF-α were detected in the same patients. Remarkably, relapsed patients exhibited a low NF-κB and iNOS expression associated with low amounts of plasmatic TNF-α and NO. Collectively, NF-κB/iNOS pathway is involved in the host defense mechanisms at the systemic and local level during primary CE. Our results indicate that the inhibition of this pathway in relapsed patients will attenuate protective immunity and promote parasite escape. This study allowed to identify a novel predictive biomarkers of hydatidosis.

Human cystic echinococcosis: Serological diagnosis by indirect hemagglutination test, enzyme-linked immunosorbent assay, immunoelectrophoresis, and immunoblotting in surgically confirmed patients versus cases diagnosed by imaging techniques

INTRODUCTION

Human cystic echinococcosis (CE) diagnosis is based on imaging findings and serology. Serology is the first-line test followed by imaging tests.

MATERIALS AND METHODS

A total of 268 serum samples from CE patients were included in this study. The serodiagnosis was made simultaneously by indirect hemagglutination assay (IHA), enzyme-linked immunosorbent assay (ELISA), immunoblotting test (IB), and immunoelectrophoresis (IEP).

RESULTS

In serum samples belonging to surgically confirmed CE patients, we observed a percentage of positivity of 83.7% [77.2%-89.0%] and 80.7% [73.9%-86.4%] for IHA and IgG-ELISA, respectively. IgG-IB was associated with a higher positivity rate than IEP with 81.3% [74.6%-86.9%] and 62.0% [54.2%-69.5%], respectively. IHA and ELISA results were analyzed using cut-off generated by receiver operating curves. The best diagnostic performances were achieved by IHA (cut-off ≥1/128) and ELISA (>1.16 index). Sensitivities reported in patients with suggestive imaging findings and positive Echinococcus IB were 86.2% [78.0%-92.2%], 72.5% [62.8%-80.9%], 49.0% [39.0%-59.1%] for IHA, IgG-ELISA, and IEP, respectively. All tests gave false negative results in the confirmed CE group. Overall, 18.6% of negative results were obtained by IgG-IB test. Cross-reactivities with non-hydatid serum samples were observed in all tests. Only one patient carrying Taenia saginata serum cross-reacted with 8/12 kDa band by IB. We observed specificity at 73% [63.2%-81.4%], 87% [78.8%-92.9%], 99% [94.6%-100.0%], and 99% [94.6%-100.0%] with IHA, IgG-ELISA, IEP, and IgG-IB, respectively. Serology was less sensitive (74%) in lung cysts. Sensitivity was better in liver cysts, especially by IgG-IB (96%).

Osseous cystic echinococcosis: A case series study at a referral unit in Spain

Background

Cystic echinococcosis (CE) is present in all continents, except for the Antarctica. Characteristically, CE lesions are found in the liver and the lungs, but virtually any part of the body may be affected (the spleen, kidneys, heart, central nervous system, bones, among others). It is estimated that the incidence of bone involvement in CE is 0.5% to 4%.

Methodology

A retrospective study was performed of patients with osseous CE treated at the National Reference Unit of Tropical Diseases of the Ramon y Cajal Hospital, Madrid, Spain, between 1989 and December 2017. Epidemiological, clinical, diagnostic and therapeutic data of patients with long-term follow-up were collected.

Main findings

During the study period, of the 104 patients with CE, 27 exhibited bone involvement (26%). The bones most frequently affected were the spine, followed by the ribs, pelvis, femur, tibia and the scapula. The most common symptom was pain followed by medullar syndrome and pathologic fracture. In total, 81.5% of patients underwent surgery for osseous CE at least once. As many as 96% received albendazol either in (mostly long-term) monotherapy or in combination with praziquantel.

Conclusions

The diagnosis and management of osseous CE is challenging. In many cases osseous CE should be considered a chronic disease and should be managed on a case-by-case basis. Lifelong follow-up should be performed for potential recurrence and sequels.

Echinococcosis occurs in humans as a result of infection by a cestodes of the genus Echinococcus. One of the species, E. granulosus, causes cystic echinococcosis (CE) in humans worldwide. In the lifecycle there is a definitive host (generally dogs) which host this parasites at the small bowel. From there, ground is shed with the eggs of the parasite through feces and the intermediate host (usually a sheep or other herbivores get infected). Humans act as an incidental intermediate host when they become infected through the consumption of water or food contaminated with Echinococcus eggs. Once the egg has been ingested, it penetrates the intestinal mucosa and through the circulatory system finds an anatomical site forming a cystic lesion (hydatid or hydatid cyst). Characteristically, CE are found in the liver and the lungs, but virtually any part of the body may be affected. Incidence of osseous CE is low, its diagnosis and management is challenging and there is little information published. In this study we report our experience at a referral unit during nearly 30 years in the management of a series of patients with osseous CE. Such information may be useful for other physicians when treating osseous CE.

Analysis of Immune Responses in Mice Orally Immunized with Recombinant pMG36e-SP-TSOL18/Lactococcus lactis and pMG36e-TSOL18/Lactococcus lactis Vaccines of Taenia solium

Cysticercosis is a cosmopolitan zoonotic parasitic disease infected by larval of Taenia solium (T. solium). Several drugs for the treatment of cysticercosis, such as praziquantel, albendazole, and mebendazole, have certain toxicity and side effects. Considering that there is no vaccine available, we studied a new vaccine for cysticercosis in this study. The complete TSOL18 gene and the optimized SP-TSOL18 gene fragments were obtained using PCR-based accurate synthesis method. The secretory and intracellular recombinant pMG36e-SP-TSOL18/Lactococcus lactis (L. lactis) and pMG36e-TSOL18/L. lactis vaccines of T. solium were prepared. Immune responses in mice orally immunized with these two recombinant L. lactis vaccines were analyzed by the determination of specific antibodies (IgG, IgG1, IgG2a, and sIgA) in serum, spleen lymphocyte proliferation, and cytokines (IL-2, IFN-γ, IL-4, and IL-10) in spleen lymphocyte culture supernatant. Our results showed that, after the first immunization, in these two recombinant L. lactis vaccine groups, the levels of serum specific IgG, IgG2a, and IgG1 increased on 14–56 d and reached the highest level on days 42, 42, and 28, respectively. The level of specific sIgA of intestinal mucosa also increased on 14–56 d and reached the highest level on day 42. The level of spleen lymphocyte proliferation increased on 14–56 d and reached the highest level on day 42. The levels of IL-2, IFN-γ, IL-4, and IL-10 in spleen lymphocyte culture supernatant increased on 14–56 d and reached the highest level on days 42, 42, 28, and 28, respectively. These results indicated that the recombinant pMG36e-SP-TSOL18/L. lactis and pMG36e-TSOL18/L. lactis vaccines can induce specific cellular, humoral, and mucosal immune responses in mice with oral vaccination. More importantly, the recombinant pMG36e-SP-TSOL18/L. lactis vaccine has a better immune effect. In summary, these results demonstrated the possibility of using L. lactis strain as a vector to deliver protective antigens of T. solium.

Demographic aspects of human hydatidosis in Iranian general population based on serology: A systematic review and meta-analysis

AIM

Human cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus cestodes, is a globally distributed chronic disease that is an important socioeconomic and public health problem in humans and livestock in developing countries, including Iran. The aim of this study was to determine the overall seroprevalence of hydatid infection in the general population of Iran.

MATERIALS AND METHODS

This systematic review began by searching electronic databases in English (PubMed, Science Direct, Scopus, and Google Scholar) and Persian (Magiran, Scientific Information Database, Iran Medex, and Iran Doc).

RESULTS

Our search resulted in a total of 40 reports published from 1995 to 2015. Of 49,460 individuals surveyed, 3090 cases of hydatidosis were reported. Community-based studies showed that the seroprevalence of CE in the Iranian general population was 6.0% (95% confidence interval: 5.0-7.0%). The age group with the highest CE seroprevalence was 20-40 years, and the lowest one was in the under 20 year's group. The seroprevalence of hydatidosis in males was significantly higher than that in females. In addition, the intended rate was significantly higher in rural regions than in urban areas.

CONCLUSION

Management program for developing more efficient diagnostic tests should be established. Further, cost-effective preventive approaches, including relevant research, should be considered. Finally, hydatid cyst control programs that are important for interrupting the transmission of human CE should be improved.

Ultrasound and Cystic Echinococcosis

The introduction of imaging techniques in clinical practice 40 years ago changed the clinical management of many diseases, including cystic echinococcosis (CE). For the first time cysts were clearly seen before surgery. Among the available imaging techniques, ultrasound (US) has unique properties that can be used to study and manage cystic echinococcosis. It is harmless, can image almost all organs and systems, can be repeated as often as required, is portable, requires no patient preparation, is relatively inexpensive and guides diagnosis, treatment and follow-up without radiation exposure and harm to the patient. US is the only imaging technique which can be used in field settings to assess CE prevalence because it can be run even on solar power or a small generator in remote field locations. Thanks to US classifications, the concept of stage-specific treatments was introduced and because US is repeatable, the scientific community has gained a clearer understanding of the natural history of the disease. This paper reviews the scope of US in CE, describes its strengths and weaknesses compared to other imaging techniques and its relationship with serodiagnosis and discusses sonographic features that may be helpful in differential diagnosis.

Pathological fracture of femoral neck in a middle-aged woman: a rare presentation of primary hydatid cyst disease in humans

Hydatid disease in humans is caused by Echinococcus granulosus. It most commonly involves the liver and, to a lesser extent, the lungs and spleen; however, it is known to involve other areas, too. Involvement of bone by hydatid cyst is rare. Here, we describe the case of a 37-year-old woman who presented with pain in the left groin and swelling in the left thigh. The radiological imaging showed a fracture of the femoral neck and cysts in the shaft of the femur. Diagnosis of hydatid cyst was confirmed on the basis of histopathology of biopsy specimens. The patient recovered after surgical excision of the cyst. This case illustrates the various sites and presentations of hydatid cyst disease, and the need to investigate for it if cystic bony lesions are encountered especially in endemic regions, as a delay in diagnosis can lead to long-term morbidity and even death.

Management of osseous cystic echinococcosis

INTRODUCTION

Osseous cystic echinococcosis (CE) is one of the most complicated and devastating conditions caused by Echinococcus granulosus. Its management is difficult and there is scant literature about it. Areas covered: A literature review was performed to provide an update on its diagnosis, treatment and follow-up. Expert commentary: In most cases diagnosis of osseous CE can only be confirmed by surgery. Osseous CE should be managed by experienced physicians and addressed as a chronic disease with therapies must be aimed at controlling the disease and its sequels or complications, rather than with a curative intent.

Case-series study of hepatic echinococcal cysts in Serbia: viability of scolices, seropositivity and epidemiological characteristics

Cystic echinococcosis (CE) is an endemic helminthic disease caused by infection with Echinococcus granulosus metacestodes. Although CE is endemic in the Balkan region, the exact epidemiology remains unknown. We conducted a case-series study with the aim of evaluating the correlation between seropositivity, socio-epidemiological data, pre-operative treatment with albendazole and viability of protoscolices in human hepatic hydatid cysts. Consecutive patients with hepatic CE underwent surgery to extract E. granulosis cysts. The viability of protoscolices was measured by their ability to absorb 0.1% eosin. Socio-epidemiological data were collected and serological testing was performed. In the present study, 38 patients (28 adults and 10 children) with hepatic CE were treated surgically. The scolex viability test was positive in 30/38 (79%) samples. All patients with non-viable cysts had seronegative results. The viability test was positive in 11/12 (91.6%) adult patients with pre-operative albendazole treatment and in 9/10 (90%) children. Statistically more patients were from an urban area compared with a rural area (65.8% vs. 15.7%). The increasing number of stray dogs shedding E. granulosus eggs in urban public areas in the Balkans might be the reason for the significant difference in the rate of infection between urban and rural areas in the present study. In addition, uncontrolled slaughtering of livestock, common in rural settlements, and feeding the infected viscera to dogs, favour the maintenance of the parasite cycle. We believe that the results of our study will encourage physicians, veterinarians and health authorities to initiate a programme to prevent and control CE in the Balkan region.

Current status of diagnosis and treatment of hepatic echinococcosis

Echinococcus granulosus (E. granulosus) and Echinococcus multilocularis (E. multilocularis) infections are the most common parasitic diseases that affect the liver. The disease course is typically slow and the patients tend to remain asymptomatic for many years. Often the diagnosis is incidental. Right upper quadrant abdominal pain, hepatitis, cholangitis, and anaphylaxis due to dissemination of the cyst are the main presenting symptoms. Ultrasonography is important in diagnosis. The World Health Organization classification, based on ultrasonographic findings, is used for staging of the disease and treatment selection. In addition to the imaging methods, immunological investigations are used to support the diagnosis. The available treatment options for E. granulosus infection include open surgery, percutaneous interventions, and pharmacotherapy. Aggressive surgery is the first-choice treatment for E. multilocularis infection, while pharmacotherapy is used as an adjunct to surgery. Due to a paucity of clinical studies, empirical evidence on the treatment of E. granulosus and E. multilocularis infections is largely lacking; there are no prominent and widely accepted clinical algorithms yet. In this article, we review the diagnosis and treatment of E. granulosus and E. multilocularis infections in the light of recent evidence.

Diagnostic value of semi-purified antigens of hydatid cyst fluid in human cystic echinococcosis

Cystic Echinococcosis (CE) is an infection caused by the larval stage of Echinococcus granulosus. The diagnosis of this disease has been problematic. Serological tests detecting antibodies against E. granulosus are the most popular and mainly use the crude Hydatid Cyst Fluid (HCF) or its components, Ag 5 and B. However, the diagnostic value of these tests is limited by the problems of specificity and/or sensitivity. The use of purified HCF antigens could be more helpful in the serodiagnosis of CE compared to the whole HCF. In the present study, we have evaluated the diagnostic value of semi-purified antigens using ELISA tests. Our results have shown that the 53 KDa antigen gave the best specificity (97.5%) and sensitivity (80%). We have also used Western Blot technique to analyze the serological profile against HCF. The results have confirmed that the most immunogenic component of HCF is the Ag 5.

Detection of serum cytokines before and after pharmacological and surgical treatment in patients with cystic echinococcosis

Human cystic echinococcosis (CE), caused by Echinococcus granulosus, is one of the most important and widespread parasitic zoonoses. One of the problems that can be encountered after treating CE patients is the risk of post-surgical relapses or treatment failure, thus a long-term clinical and serological follow-up is required to evaluate the success or failure of therapy. In the present study immunological markers have been identified to indicate the effectiveness of pharmacological and surgical treatments. The relationship between serum cytokine levels and the outcome of chemotherapy and surgery was evaluated in 50 patients with CE. Serum interleukin (IL)-4, IL-10 and interferon-gamma (IFN-γ) concentrations were determined by enzyme-linked immunosorbent assay (ELISA) before and after pharmacological and surgical treatment. Serum cytokine levels of IL-4, IL-10 and IFN-γ were elevated in a significant proportion of patients during the active stage of disease. IL-4, IL-10 and IFN-γ were measurable in 41 (82%), 37 (74%) and 25 (50%) patients before the treatment. Clinical and radiological assessment of patients 2 years after pharmacological treatment has shown that 48 of 50 patients responded to treatment. IL-4 and IL-10 levels were decreased significantly (P< 0.05) in these patients. Conversely, patients who did not respond showed high levels of IL-4 and IL-10 and undetectable levels of IFN-γ. Hence these results suggest that serum IL-4 and IL-10 detection may be useful in the follow-up of patients with CE.

Lateral flow test using Echinococcus granulosus native antigen B and comparison of IgG and IgG4 dipsticks for detection of human cystic echinococcosis

Cystic echinococcosis (CE) caused by infection with Echinococcus granulosus is of major concern for humans in many parts of the world. Antigen B was prepared from E. granulosus hydatid fluid, and Western blots confirmed eight batches showing a band corresponding to the 8-/12-kDa subunit with positive serum and no low-molecular mass band (< 15 kDa) with negative serum. The batches were pooled and used to prepare lateral flow immunoglobulin G4 (IgG4) and IgG dipsticks. Diagnostic sensitivity was determined using serum samples from 21 hydatidosis patients, and diagnostic specificity was established using sera from 17 individuals infected with other parasites and 15 healthy people. IgG4 dipstick had a diagnostic sensitivity of 95% (20 of 21) and a specificity of 100% (32 of 32). The IgG dipstick had a sensitivity of 100% (21 of 21) and a specificity of 87.5% (28 of 32). Thus, both IgG and IgG4 dipsticks had high sensitivities, but IgG4 had greater specificity for the diagnosis of human CE.

Cystic echinococcosis of the liver: A primer for hepatologists

Cystic echinococcosis (CE) is a complex, chronic and neglected disease with a worldwide distribution. The liver is the most frequent location of parasitic cysts. In humans, its clinical spectrum ranges from asymptomatic infection to severe, potentially fatal disease. Four approaches exist in the clinical management of CE: surgery, percutaneous techniques and drug treatment for active cysts, and the ”watch and wait” approach for inactive cysts. Allocation of patients to these treatments should be based on cyst stage, size and location, available clinical expertise, and comorbidities. However, clinical decision algorithms, efficacy, relapse rates, and costs have never been properly evaluated. This paper reviews recent advances in classification and diagnosis and the currently available evidence for clinical decision-making in cystic echinococcosis of the liver.

Immunoproteomics approach for EPC1 antigenic epitope prediction of G1 and G6 strains of Echinococcus granulosus

It is important to establish the diagnosis of cystic echinococcosis (CE) infection and begin control management. Currently, it is difficult to make an accurate diagnosis of CE without the availability of an accurate test, which requires the use of sensitive and specific antigens. Using recombinant antigens the sensitivity and specificity of the CE serology assays could be improved considerably. Recently, a highly antigenic protein named EPC1was characterized and isolated from an Echinococcus granulosus protoscoleces. The current study was designed to assess the sequences of EPC1 isolated from different intermediate hosts of E. granulosus. In addition, identification of a highly antigenic linear B cell epitope was found within EPC1 antigen candidate. The EPC1 sequence contains coding and non-coding regions and was compared between two predominant strains (G1 and G6) in Iran. Sequence polymorphism was not found in protein coding regions, suggesting that these regions may be useful for identification of protein expression as an antigen. The average antigenic activity for the whole protein is above 1.1, and hydrophobicity below 0 indicates that it is hydrophilic. Structural analysis showed alpha helical regions in amino acids 6-25, 35-44, 52-62, and 72-78. Nine B cell epitope residues were identified out of 67 total residues. The identity of EPC1 sequence in both G1 and G6 genotypes affects the antigenic efficacy of EPC1and suggests the recombinant protein will be useful in serological assays in the regions where the two strains are prevalent.

IgG4 detection of Echinococcus granulosus paramyosin is a useful diagnostic test for human hydatidosis

Hydatidosis is a public health problem in many parts of the world, and improvement in diagnosis of the disease is still being pursued. Protoscoleces of Echinococcus granulosus were isolated from hydatid cysts collected from naturally infected sheep slaughtered in abattoirs in Iran. Sonicated extract of protoscolex was subjected to two-dimensional gel electrophoresis and Western blot analysis. Primary antibodies were from serum samples from 130 hydatidosis patients, 38 individuals infected with other parasitic infections, and 30 healthy people, whereas peroxidase (HRP)-conjugated anti-human IgG and IgG4 were used as secondary antibodies. The recombinant form of the identified protein was produced and tested for its sensitivity and specificity for the detection of human hydatidosis. An antigenic band of ∼60 kDa was found to be sensitive (82%) and specific (100%) for the detection of hydatidosis when probed with anti-human IgG4-HRP, while the sensitivity and specificity were 33 and 100%, respectively, with anti-human IgG-HRP. By mass spectrometry, the band was identified as protoscolex tegument paramyosin. The sensitivity and specificity of full-length paramyosin-recombinant protein in IgG4 blots were found to be 86 and 98%, respectively. In conclusion, IgG4 detection of Echinococcus granulosus paramyosin was found to be useful for the diagnosis of human hydatidosis.

A pilot study on developing mucosal vaccine against alveolar echinococcosis (AE) using recombinant tetraspanin 3: Vaccine efficacy and immunology

Background

We have previously evaluated the vaccine efficacies of seven tetraspanins of Echinococcus multilocularis (Em-TSP1–7) against alveolar echinococcosis (AE) by subcutaneous (s.c.) administration with Freund's adjuvant. Over 85% of liver cyst lesion number reductions (CLNR) were achieved by recombinant Em-TSP1 (rEm-TSP1) and -TSP3 (rEm-TSP3). However, to develop an efficient and safe human vaccine, the efficacy of TSP mucosal vaccines must be thoroughly evaluated.

Methodology/Principal Findings

rEm-TSP1 and -TSP3 along with nontoxic CpG ODN (CpG oligodeoxynucleotides) adjuvant were intranasally (i.n.) immunized to BALB/c mice and their vaccine efficacies were evaluated by counting liver CLNR (experiment I). 37.1% (p<0.05) and 62.1% (p<0.001) of CLNR were achieved by these two proteins, respectively. To study the protection-associated immune responses induced by rEm-TSP3 via different immunization routes (i.n. administration with CpG or s.c. immunization with Freund's adjuvant), the systemic and mucosal antibody responses were detected by ELISA (experiment II). S.c. and i.n. administration of rEm-TSP3 achieved 81.9% (p<0.001) and 62.8% (p<0.01) CLNR in the liver, respectively. Both the immunization routes evoked strong serum IgG, IgG1 and IgG2α responses; i.n. immunization induced significantly higher IgA responses in nasal cavity and intestine compared with s.c. immunization (p<0.001). Both immunization routes induced extremely strong liver IgA antibody responses (p<0.001). The Th1 and Th2 cell responses were assessed by examining the IgG1/IgG2α ratio at two and three weeks post-immunization. S.c. immunization resulted in a reduction in the IgG1/IgG2α ratio (Th1 tendency), whereas i.n. immunization caused a shift from Th1 to Th2. Moreover, immunohistochemistry showed that Em-TSP1 and -TSP3 were extensively located on the surface of E. multilocularis cysts, protoscoleces and adult worms with additional expression of Em-TSP3 in the inner part of protoscoleces and oncospheres.

Conclusions

Our study indicated that i.n. administration of rEm-TSP3 with CpG is able to induce both systemic and local immune responses and thus provides significant protection against AE.

Humans and rodents become infected with E. multilocularis by oral ingesting of the eggs, which then develop into cysts in the liver and progress an endless proliferation. Untreated AE has a fatality rate of >90% in humans. Tetraspanins have been identified in Schistosoma and showed potential as the prospective vaccine candidates. In our recent study, we first identified seven tetraspanins in E. multilocularis and evaluated their protective efficacies as vaccines against AE when subcutaneously administered to BALB/c mice. Mucosal immunization of protective proteins is able to induce strong local and systemic immune responses, which might play a crucial role in protecting humans against E. multilocularis infection via the intestine, blood and liver. We focused on Em-TSP3, which achieved significant vaccine efficacy via both s.c. and i.n. routes. The adjuvanticity of nontoxic CpG OND as i.n. vaccine adjuvant was evaluated. The widespread expression of Em-TSP3 in all the developmental stages of E. multilocularis, and the strong local and systemic immune responses evoked by i.n. administration of rEm-TSP3 with CpG OND adjuvant suggest that this study might open the way for developing efficient, nontoxic human mucosal vaccines against AE.

Bovine (Bos taurus) humoral immune response against Echinococcus granulosus and hydatid cyst infertility

Echinococcus granulosus, the agent of hydatid disease, presents an indirect life cycle, with canines (mainly dogs) as definitive hosts, and herbivores and human as intermediary ones. In intermediary hosts fertile and infertile cysts develop, but only the first ones develop protoscoleces, the parasite form infective to definitive hosts. We report the presence of bovine IgGs in the germinal layer from infertile cysts (GLIC), in an order of magnitude greater than in the germinal layer from fertile cysts (GLFC). When extracted with salt solutions, bovine IgGs from GLIC are associated with low or with high affinity (most likely corresponding to non specific and antigen specific antibodies, respectively). Specific IgGs penetrate both the cells of the germinal layer and HeLa cultured cells and recognize parasitic proteins. These results, taken together with previous ones from our laboratory, showing induction of apoptosis in the germinal layer of infertile hydatid cysts, provide the first coherent explanation of the infertility process. They also offer the possibility of identifying the parasite antigens recognized, as possible targets for immune modulation.

Human cystic echinococcosis: old problems and new perspectives

Cystic echinococcosis (CE) is a widespread chronic endemic helminthic disease caused by infection with metacestodes of the tapeworm Echinococcus granulosus. CE affects humans and has a worldwide prevalence of approximately six million. In this review, we discuss current findings in diagnosis and clinical management of CE and new concepts relating to E. granulosus molecules that directly modulate the host immune responses favouring a strong anti-inflammatory response and perpetuating parasite survival in the host. New insights into the molecular biology of E. granulosus will improve considerably our knowledge of the disease and will provide new potential therapeutic applications to treat or prevent inflammatory immune-mediated disease.

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.

Transdiaphragmatic amyloidoma

The term "amyloidoma" has been used to describe localized pulmonary nodular amyloidosis when it is a solitary lesion. Amyloidoma is an uncommon and infrequently reported cause of benign pulmonary lesions. We report the case of a 45-year-old man with hemoptysis, eosinophilia, and a large mass involving both lobes of the left lung, the chest wall, and, via extension through the diaphragm, the liver. Clinical suspicion of echinococcal cyst led to treatment via en bloc excision rather than attempting tissue biopsy for diagnosis. Complete resection of the isolated pulmonary amyloidoma was achieved with no evidence of recurrence.

Usefulness of four different Echinococcus granulosus recombinant antigens for serodiagnosis of unilocular hydatid disease (UHD) and postsurgical follow-up of patients treated for UHD

Four different recombinant antigens derived from Echinococcus granulosus, designated B1t, B2t, E14t, and C317, were tested with enzyme-linked immunosorbent assays (ELISAs) for the detection of specific immunoglobulin G (IgG) in patients with unilocular hydatid disease (UHD). The results were compared to those obtained with hydatid fluid and were subjected to receiver operator characteristic analysis. The diagnostic performance of the above-listed proteins was defined with respect to their specificity, sensitivity, and predictive values (PV); the influence of cyst location; and usefulness in the follow-up of surgical treatment for UHD and in the determination of whether or not patients have been surgically cured of UHD. The best diagnostic results were obtained with the anti-B2t IgG ELISA, with 91.2% sensitivity, 93% specificity, and high positive and negative PV (89.4 and 94.2, respectively). In addition, this diagnostic tool proved to be useful for the follow-up of surgically treated UHD patients. The anti-B2t IgG ELISA may find an application in the serodiagnosis of UHD in clinical laboratories.

[Recent advances in the immunodiagnosis of human cystic echinococcosis]

Human cystic echinococcosis is a severe zoonotic infection caused by the larval stage of the taeniid tapeworm Echinococcus granulosus. The infection may be fatal if proper treatment is not provided; hence, early diagnosis is very important. Currently, ELISA and immunoblotting are the most reliable tests for serodiagnostic purposes, although their accuracy is largely dependent on the quality of the antigenic source used. Hydatid cyst fluid has been the antigenic extract of choice for primary immunodiagnosis of the disease, which is mainly based on the detection of antigens B and 5. Several problems are associated with this extract, however, including a lack of sensitivity and specificity, and difficulties with standardization of its use. This paper reviews recent advances in the identification and characterization of novel antigens that may be useful for the immunodiagnosing of human cystic echinococcosis, with emphasis on progress in recombinant technologies and synthetic peptides. Novel approaches are discussed, such as the design of antigenic extracts from other developmental stages of the parasite, as well as the usefulness of serum cytokine detection in the clinical follow-up of affected patients after surgical or pharmacological treatment.

The immunodiagnosis of Echinococcus multilocularis infection

Alveolar echinococcosis (AE) is a severe zoonotic disease caused by the metacestode stage of Echinococcus multilocularis. The infection can have fatal consequences in humans if treatment is not provided, so early diagnosis is fundamental for initiating treatment and reducing morbidity and mortality. In addition, detection of the parasite in the definitive host plays a central role in epidemiological studies and surveillance programmes for control of AE. This review presents an overview of the present situation regarding the immunodiagnosis of E. multilocularis infection. Special attention is given to the description of the native, partially purified and recombinant antigens available currently for immunodiagnostic purposes. Recent advances in the primary serodiagnosis and follow-up of AE patients are highlighted, including the detection of specific cytokine profiles. Progress in the immunodiagnosis of intestinal E. multilocularis infection in definitive hosts, particularly the detection of excretory-secretory and integument products of the worm in faeces (copro-antigens) by ELISA, is also discussed.

Antibody responses in human cystic hydatid disease to the laminated layer of Echinococcus granulosus

The laminated layer of hydatid cysts of Echinococcus granulosus represents a considerable amount of parasite material. Its antigenic role, however, is unclear. Extracts of laminated layer taken from sheep cysts were analysed in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE) and were found to contain bands at 55 and 25-29 kDa, which reacted with an anti-sheep IgG antibody probe, indicating that these were likely to be host-contaminating components within the layer. However, the same bands were also recognised by a significant proportion of human hydatid patients, particularly by IgG4 antibodies, and not by negative control individuals. These individuals did not recognise immunoglobulin heavy and light chains in a sheep serum extract in the same manner. It seems likely that there are either host or parasite antigenic components at similar molecular weights or that certain parasite antigens may share epitopes with sheep immunoglobulins. The antigens at 25-29 kDa were found to be glycoproteins by lectin blot analysis and may be important markers of disease status.

A correlative study of ultrasound with serology in an area in China co-endemic for human alveolar and cystic echinococcosis

We correlated ultrasound (US) imaging classifications for human alveolar echinococcosis (AE) and cystic echinococcosis (CE) with serology (ELISA and immunoblotting (IB) incorporating native and recombinant/purified echinococcal antigens) in community surveys (2001-2003) and follow-up (2002 and 2003) of US-confirmed cases in Ningxia, China. One hundred and seventy-one cases (96 with AE, 75 with CE) were identified; of these, US classification and serological data were obtained for 142 and 112 cases, respectively. Seropositive-rates increased in CE patients with highly viable unilocular cyst lesions (Types CL, CE 1 or CE 2) to degenerating primary lesions (CE 3), but then decreased in subjects with inactive (CE 4) or dead (CE 5) cysts. In contrast, there was a constant increase in seropositivity from the early (P1, P2) to the advanced stages (P3, P4) with AE cases. For US-confirmed cases, follow-up by US combined with serology is invaluable for studying the clinical progression of echinococcosis and for detecting recurrent cysts or reinfection post-treatment.

IgG serum antibody responses in suspected liver cystic echinococcosis patients

Introduction: Cystic echinococcosis is a parasitic zoonosis caused by a tapeworm Echinococcus granulosus. Liver infection is the most common form of human echinococcosis. Diagnosis of liver echinococcosis could be made by different methods. It is very important to have good anamnesis and epidemiological evaluation, clinical status and clinical investigations such as X-ray examination, ultrasonography, nuclear magnetic resonance, computerized tomography, laboratory analysis and serology. Different serologic tests could be used for diagnosis of echinococcosis: complement fixation test, immunoelectrophoresis, indirect haemagglutination, latex agglutination, indirect fluorescence test and enzyme immunoassays sush as ELISA test. Objective. The aim of this study was to investigate anti-E. granulosus antibodies by ELISA test as a complementary laboratory method in the diagnosis of human echinococcosis. Method. In this study, we investigated 212 patients of suspected liver cystic echinococcosis. ELISA test was used for detection of whole anti-E. granulosus IgG antibodies specific for AgB. Results. Out of 212 patients, in 26 (12.26%) patients echinococcosis was confirmed by ELISA test. In 7/26 patients who had data about the ultrasonographic morphological type of cyst according to Gharbi, high values of seropositivity were found. Borderline values were found in 15/212 (7.08%) patients. In three patients with borderline values, second sera samples were examined after 18-22 days. In one patient, the test showed the same value, in the second patient echinococcosis was confirmed while in the third, the test showed a negative value. In 171 (80.66%) patients, anti-Echinococcus antibodies were not found by ELISA test. Conclusion. It has already been known that serological investigation has some limitations, but detection of specific antibodies remains an indispensable mark in evaluation of suspected liver cystic echinococcosis patients. .

Analysis of specific IgE and IgG subclass antibodies for diagnosis of Echinococcus granulosus

The potential roles of specific antibodies of different immunoglobulin G (IgG) subclasses and IgE in serological diagnosis of cystic echinococcosis (CE) were investigated by an enzyme linked immunosorbent assay (ELISA) based on Antigen 5 (Ag5). Presence of IgG1 was demonstrated in all sera from 58 patients with CE. The most discriminatory and specific antibodies found in this study belonged to IgG4 and IgE. Only one false-positive reaction was observed with IgG4 and no IgE cross-reactivity occurred with 40 sera from healthy controls. In 36 sera from patients infected with parasites other than CE two false-positive reactions with IgG4 were observed but none occurred with IgE. In immunoblotting, it was shown that IgG1 subclass was responsible for cross-reactivity of human antibodies that reacted with a 38 kDa subunit of Ag5. IgG4 and IgE antibodies could not recognize the 38 kDa subunit and under non-reducing conditions reacted with the 57 kDa subunit without any cross-reactivity to other parasites. The results demonstrated that IgG4 and IgE are the most important antibodies for serological diagnosis of hydatid cyst in an Ag5 based immunoassay system.

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.

33-jährige Libanesin mit rezidivierenden Hämoptysen und zystischer Raumforderung in der Lunge

A 33 year old woman from Lebanon presented with recurrent hemoptysis, subfebrile temperature, dyspnoe in stress, fatigue, weight loss, and pruritus. Serological tests and results from chest X-ray and computer tomography revealed cystic echinococcosis with pulmonary involvement. After refusal of surgical therapy a medical treatment with albendazole was implemented. Two months after the start of the therapy only a small fibrotic residuum in the lung was seen. A spontaneous healing success seems unlikely because of the duration of the pulmonary cyst and the progressive symptoms before treatment.

Antigens for the immunodiagnosis of Echinococcus granulosus infection: An update

The taeniid tapeworm Echinococcus granulosus is the causative agent of the echinococcal disease, an important zoonosis with worldwide distribution. Accurate immunodiagnosis of the infection requires highly specific and sensitive antigens to be used in immunodiagnostic assays. The choice of an appropriate source of antigenic material is a crucial point in the improvement of the diagnostic features of tests, and must be based on the developmental stage of the parasite and the host. The most common antigenic sources used for the immunodiagnosis of echinococcal disease are hydatid cyst fluid, somatic extracts and excretory-secretory products from protoscoleces or adults of E. granulosus. Hydatid cyst fluid is the antigenic source of reference for immunodiagnosis of human hydatidosis, which is mainly based on the detection of antigens B and 5. Somatic extracts have been widely used in the serodiagnosis for E. granulosus infection in dogs and ruminant intermediate hosts, although in the last few years the detection of excretory-secretory products of the worm in faeces (coproantigens) have become the most reliable method for the detection of the parasite in the definitive host. This review emphasizes recent advances in the identification and characterization of novel antigens with potential for the immunodiagnosis of echinococcal disease. Progress in recombinant technologies and synthetic peptides are also discussed. The paper highlights the need to search for new antigenic components with high diagnostic sensitivity and specificity, a fact that remains a crucial task in the improvement of the immunodiagnosis of the disease.