Treatment of liver hydatidosis: How to treat an asymptomatic carrier?

Management of a hydatid cyst in a center with high prevalence. Descriptive series

Hydatidosis is a zoonosis caused by the larval stage of the genus Echinococcus. Humans are an accidental intermediate host. The main organ affected is the liver (70%). The incidence increases in endemic regions such as North Africa, Eastern Europe and South America. We present a descriptive series of cases treated in our hospital in the last 5 years. Demographic variables, cyst characteristics, as well as preoperative and postoperative variables are collected.

Autoimmunity in human CE: Correlative with the fertility status of the CE cyst

Cystic echinococcosis is speculated to exert several immune-evasion strategies involving autoimmune-phenomena. We evaluated the hypothesizes that the prevalence of autoantibodies increases in the sera of CE patients that may evidence the association between the parasite and autoimmune diseases. Sera from 63 subjects at distinct types of CE cyst fertility were investigated for antinuclear antibodies (ANA), and anti-CCP antibodies. Plasma levels and cellular production of IL-17A cytokine were specifically defined as being assumed to prime for autoimmunity. Healthy-controls were age and gender-matched to test sera. ANA expressions inside the surgically removed metacestode and adventitial layer were also assayed. Out of 63 patients, 35 % had fertile highly viable cysts (group-1), 41 % had fertile low viable cysts (group-2) and 24 % had non-fertile cysts (group-3). A four-fold increase in ANA sera-levels was detected in group-1 compared with their controls (p-value 0.001) while anti-CCP levels were of insignificant differences. In group-2 and group-3, no significant differences were detected between ANA and anti-CCP sera-levels in CE patients and their controls. IL-17A sera-levels in group-1 and group- 2 were significantly higher than their healthy-controls while being of insignificant differences in group-3, p-value= 0.300. No association was detected between sera-levels of IL-17A and ANA as well as anti-CCP antibodies. Interestingly, relative IL-17A cellular expression associated positive ANA deposition in the parasite cells and adventitial layer. Collectively, based on the parasite fertility, IL-17A and ANA seemed to be involved in the host immune defenses against CE. There is no association between CE and anti-CCP antibodies.

Can parasite-derived microRNAs differentiate active and inactive cystic echinococcosis patients?

Cystic Echinococcosis (CE) is a neglected zoonotic disease caused by the metacestode form of Echinococcus granulosus sensu lato. Non-invasive imaging techniques, especially ultrasound, are primarily used for CE diagnosis. MicroRNAs (miRNAs) are small, non-coding RNA molecules that act as post-transcriptional regulators in various biological processes. After identification of parasite-derived miRNAs, these miRNAs are considered to be potential biomarkers for diagnosis and follow-up. The focus of this research is to compare the expression profiles of certain parasite-derived miRNAs in CE patients with active and inactive cysts as well as healthy controls. Parasite-derived miRNAs, egr-let-7-5p, egr-miR-71a-5p, and egr-miR-9-5p, of inactive CE patients were found to be differentially expressed with 3.74-, 2.72-, and 20.78-fold change (p < 0.05), respectively, when compared with active CE patients. In this study, we evaluated for the first time the expression profile of three parasite-derived miRNAs in the serum of CE patients to determine their potential to distinguish between active and inactive CE. It was concluded that serum levels of parasite-derived miRNAs, egr-let-7-5p and egr-miR-9-5p, could be promising new potential biomarkers for stage-specific diagnosis of CE. Further studies are needed with larger sample set to validate discriminating potential of these miRNAs.

Mid-term Outcomes of Laparoscopic Total Cystectomy Versus Open Surgery for Complicated Liver Hydatid Cysts

Total cystectomy is a challenging procedure in patients with complicated liver hydatid cysts (HCs). This study aimed to evaluate the feasibility and safety of laparoscopic total cystectomy in patients with complicated liver HCs.

Epidemiology, diagnosis, treatment and follow-up of cystic echinococcosis in asymptomatic carriers

Background

Río Negro Province is endemic for cystic echinococcosis (CE). A CE control program includes early diagnosis in humans. During 1980-1996, screening was done with serology and surgery was the unique choice of treatment. Since 1997, ultrasound (US) has been the method of choice for screening, and new choices of treatment for asymptomatic carriers are discussed in the CE guidelines.

Methods

Between 1997 and 2016, 42 734 abdominal USs were performed, 192 new asymptomatic cases were diagnosed and underwent a protocol according to the size, location and type of cyst. Treatment options included active surveillance (US monitoring, 83 [43.3%]), antiparasitic (albendazole, 92 [47.9%]) and surgery (17 [8.8%], including percutaneous treatment).

Results

After 7.7 y of follow-up, of the cases under active surveillance, 28 (33.7%) had to change treatment: 5 (6%) to surgery and 22 (26.5%) to albendazole. Of the patients treated with albendazole, 3 (3.2%) were operated on and 13 (14%) were treated with a second cycle of albendazole.

Conclusion

As a result of the present study, resolution of CE in a non-surgical way with albendazole is confirmed to be effective in asymptomatic carriers with CE1 or CE3a cysts. An update eliminates the strategy of active surveillance in type CE1 cysts <3 cm and is replaced by treatment with antiparasitic in all asymptomatic cases with CE1 or CE3a cysts <10 cm. The update also limits follow-up to 12-18 months to evaluate those cases with non-response to antiparasitic and switch to a surgical option.

Control of cystic echinococcosis: Background and prospects

Cystic echinococcosis (CE), caused by Echinococcus granulosus, is a chronic and debilitating zoonotic larval cestode infection in humans, which is principally transmitted between dogs and domestic livestock, particularly sheep. Human CE occurs in almost all pastoral communities and rangeland areas of the underdeveloped and developed world. Control programmes against CE have been implemented in several endemic countries to reduce or eliminate the disease. New Zealand and Tasmania are examples of some of the first programmes to be undertaken (in insular territories) and which were very successful in the elimination of CE. The advent and proven effectiveness of praziquantel, plus the experience of insular models, produced high expectations for rapid advances in a second generation of control programmes undertaken in continental areas (Argentina, Uruguay and Chile). Nevertheless, only moderate gains in CE control have been made and the impact on prevalence among humans has been slight. A major impediment to the adoption of procedures that were successful in New Zealand and Tasmania has been the requirement to administer praziquantel to dogs in rural areas eight times per year over numerous years. In addition, there have been clear technological improvements made in the diagnosis of canine echinococcosis for surveillance, the genetic characterization of parasite strains and in vaccination against CE infection in livestock. In order to establish new paradigms and appropriate combinations of control strategies, we have carried out a review and discussion of the available control tools and control models. Control strategies must be suitable and sustainable to benefit the Echinococcosis-endemic areas primarily, which at the same time are the poorest regions of the world.

Evaluation of the recombinant antigens B2t and 2B2t, compared with hydatid fluid, in IgG-ELISA and immunostrips for the diagnosis and follow up of CE patients

Cystic echinococcosis (CE) is one of the most widespread helminthic zoonoses and is caused by the tapeworm Echinococcus granulosus complex. CE diagnosis and monitoring primarily rely on imaging techniques, complemented by serology. This is usually approached by the detection of IgG antibodies against hydatid fluid (HF), but the use of this heterogeneous antigenic mixture results in a variable percentage of false positive and negative results, and has shown to be useless for follow-up due to the long persistence of anti-HF antibodies in cured patients. To improve test performances and standardization, a number of recombinant antigens mainly derived from HF have been described, among them the B2t and 2B2t antigens. The performance of these antigens in the diagnosis and follow up of patients with CE has been so far evaluated on a limited number of samples. Here, we evaluated the performances of tests based on B2t and 2B2t recombinant antigens compared to HF in IgG-ELISA and immunochromatography (IC) for the diagnosis and follow-up of patients with CE in a retrospective cohort study. A total of 721 serum samples were collected: 587 from 253 patients with CE diagnosed by ultrasonography (US), 42 from patients with alveolar echinococcosis and 92 from healthy donors from Salamanca (Spain). The highest overall sensitivity was obtained with HF in ELISA (85.5%), followed by IC containing HF and 2B2t-HF (83.0% and 78.2%, respectively). The lowest sensitivity was obtained with B2t and 2B2t in ELISA (51.8%). The highest specificity was obtained with IC containing 2B2t-HF (100%), and the lowest with HF-ELISA (78.0%). The lowest cross-reactivity with sera from patients with alveolar echinococcosis was detected with the recombinant antigens in ELISA (9.5% - 16.7%) and the highest with the HF-IC (64.3%). The results of B2t and 2B2t-ELISA were influenced by cyst stage, as classified by US according to the WHO-Informal Working Group on Echinococcosis (WHO-IWGE), with low sensitivity for inactive (CE4 and CE5) cysts, and by the drug treatment, with higher sensitivity in patients after drug treatment compared with patients not subjected to drug treatment. The two recombinant antigens in ELISA provided promising results for monitoring patients in follow-up, although their use is limited to patients with positive serology against them at the beginning of the follow-up. Potential biological reasons behind the low sensitivity of the recombinant antigens and possible strategies to enhance the performance of CE serology are discussed.

Cystic echinococcosis (CE) is a helminthic zoonosis caused by Echinococcus granulosus sensu lato. CE diagnosis and monitoring is of paramount importance for the clinical management of patients and primarily rely on imaging techniques, complemented by serology. CE serology is usually based on the detection of antibodies against hydatid fluid (HF), but the use of this heterogeneous antigenic mixture shows several drawbacks, including false positive and negative results, unsatisfied predictive values, and long persistence of detectable antibody levels in cured patients. As an alternative, to improve test performances and standardization, several recombinant antigens have been described, but these have been so far evaluated only on a limited number of samples. Here, two recombinant antigens derived from one of the immunodominant HF antigens (antigen B2) have been tested in enzyme-linked immunosorbent assay (ELISA) and in immunochromatographic strips (IC) against 721 serum samples. Although more specific than the HF, the recombinant antigens in ELISA showed low sensitivity for patients with inactive (CE4 and CE5) cysts and for patients not subjected to drug treatment. This limited their use for follow-up, although promising, to those patients with positive serology at the beginning of the follow-up period. These results will aid in the future development of a serological test with enhanced performance in the diagnosis and follow-up of patients with CE.

The Non-operative Management of Asymptomatic Liver Hydatids: Ending Echinococcophobia

BACKGROUND

Cystic echinococcosis is common in many countries and involves the liver in 75% of cases. The current belief is that all incidentally discovered asymptomatic liver hydatids must be subjected to some types of interventional treatments pre-emptively for fear of some presumably impending complications. We conducted this study to assess the prognosis of patients with liver hydatids without any surgical interventions. Furthermore, we tried to predict the outcome of the cyst using two radiological signs.

METHODS

Of 434 asymptomatic patients with liver cysts who referred to our center, 297 were found eligible to be monitored at 1-3-year intervals by unenhanced computed tomography (CT) over a 20-year period. The patients were given the option of either having their cysts removed by open operation (the surgical group) or entering an open-ended "watch-and-wait" program (the surveillance group). Using unenhanced CT, cyst size, laminated membrane detachment (LMD), and pericyst degenerative changes (PDCs) were evaluated every 1-3 years. If a complication happened or the cyst size increased during the follow-up period, the cyst outcome was considered "unfavorable"; otherwise, it was considered "favorable."

RESULTS

Forty-three patients with 56 liver cysts were operated upon without morbidity or mortality. One hundred and twenty-seven patients with 137 cysts were followed. After a median follow-up of 6 (IQR 3 to 10) years, 111 (81.0%) had favorable outcome and 26 (19.0%) cysts had an unfavorable outcome. The size of 69 (50.4%) cysts with favorable outcome was not changed. It was decreased by a mean of 35.7% (SD 17.5%) in 34 (24.8%) cysts; 8 (5.8%) cysts disappeared. Of 26 cysts with unfavorable outcome, 8 (5.8%) developed complications (6 fistulas and 2 secondary infections) after a median follow-up of 6.5 (IQR 2.3 to 12.8) years. The size of the remaining 18 cysts increased by a mean of 42.2% (SD 29.5%). Albendazole administered at a dose of 400 mg, po, bid for 3 years, had a significant effect on hydatids. After adjustment for cyst size at diagnosis and patient's age and sex, logistic regression analysis showed that being univesicular (OR 6.00, 95% CI 1.32 to 27.29), having LMD (OR 5.51, 95% CI 1.03 to 29.43), and the presence of PDCs (OR 4.25, 95% CI 1.36 to 13.30) were independent predictors of a favorable outcome for a cyst.

CONCLUSIONS

More than 80% of asymptomatic liver hydatids have a favorable outcome without pre-emptive surgical interventions. The presence of LMD at any stage and/or PDCs of any grade justifiably exempts asymptomatic univesicular liver hydatids from any treatments. Those without LMD or PDCs can be effectively managed with long-term albendazole, artificially inducing larval involution.

Long-term sonographic and serological follow-up of inactive echinococcal cysts of the liver: hints for a "watch-and-wait" approach

Human cystic echinococcosis is a chronic, complex and neglected infection. Its clinical management has evolved over decades without adequate evaluation of efficacy. Recent expert opinion recommends that uncomplicated inactive cysts of the liver should be left untreated and solely monitored over time ("watch-and-wait" approach). However, clinical data supporting this approach are still scant and published mostly as conference proceedings. In this study, we report our experience with long-term sonographic and serological follow-up of inactive cysts of the liver. From March 1994 to October 2013, 38 patients with 47 liver cysts, diagnosed as inactive without any previous treatment history, were followed with ultrasound and serology at 6-12 months intervals for a period of at least 24 months (median follow-up 51.95 months) in our outpatient clinic. In 97.4% of patients, the cysts remained inactive over time and in only one case was reactivation of the cyst detected. No complications occurred during the time of monitoring. During follow-up, serology tests for CE were negative at diagnosis or became negative in 74.1% and were positive or became positive in 25.9% of cases. Patients with inactive cysts on ultrasound but positive serological tests were also investigated by CT scan (chest and abdomen) to rule out extra-hepatic cyst localization. This study confirms the importance of a stage-specific approach to the management of cystic echinococcosis and supports the use of a monitoring-only approach to inactive, uncomplicated cysts of the liver. It also confirms that serology plays only an ancillary role in the clinical management of these patients, compared to ultrasound and other imaging techniques. The implications of these findings for clinical management and natural history of cystic echinococcosis are discussed.

The destructive effects of high-intensity focused ultrasound on hydatid cysts enhanced by ultrasound contrast agent and superabsorbent polymer alone or in combination

Cystic echinococcosis, caused by the metacestode stage of Echincoccus granulosus, remains endemic in many regions around the world. The present work evaluated whether or not a superabsorbent polymer (SAP) and ultrasound contrast agent (UCA) alone or in combination could enhance damage efficacy of high-intensity focused ultrasound (HIFU) on hydatid cysts in vitro. HIFU of 100 W acoustic power, with the aid of 0.1 ml UCA and 0.1 g SAP alone or in combination, was used to ablate hydatid cysts in vitro. The comparison of ultrasound image for each layer of hydatid cyst before and after HIFU ablation was made immediately, and the protoscolices of the cysts were stained by eosin exclusion assay, and the structures of protoscolices were observed by light microscopy. To understand the destructive effects of HIFU, the pathological changes in cyst walls of hydatid cyst ablated with HIFU were examined. The results demonstrated that HIFU had some lethal effect on hydatid cysts: echo enhancement of ultrasound image, increase of mortality rate of protoscolices, serious structural damage of protoscolices, and complete destruction or even disappearance of laminated layer and germinal layer was observed in the group of HIFU combined with UCA and SAP alone or in combination. It was found that the destructive effect of HIFU aided with a combination of UCA and SAP to hydatid cysts was more effective than that of HIFU just aided with UCA or SAP alone. These results suggested that UCA and SAP might be used as a HIFU enhancing agent to improve the efficacy of HIFU ablation to hydatid cysts, which could be a possible therapeutic option for cystic echinococcosis.

In vitro effects of some herbs used in Egyptian traditional medicine on viability of protoscolices of hydatid cysts

The present work evaluated the effects of alcoholic extracts of salvia (Salvia officinalis), thyme (Thymus vulgaris), and 2 pure compounds (thymol and menthol) on the viability of Echinococcus granulosus protoscolices in vitro. Four different concentrations of each extract (2,500, 1,500, 1,000, and 500 µg/ml) and 3 different concentrations each of thymol and menthol (50, 10, and 1 µg/ml) were used. Concentration of 2,500 µg/ml of both extracts showed a significant protoscolicidal activity on the 6th day. Complete loss of viability of protoscolices occurred with 500 µg/ml concentration of both extracts at day 6 and day 7 post-treatment (PT), respectively. Pure compounds, i.e., menthol and thymol, showed potent effects with 50 µg/ml concentration at day 2 and day 5 PT, respectively. These effects were compared with those of albendazole sulfoxide (800 µg/ml), a commonly used treatment drug for hydatidosis. Krebs-Ringer solution and the hydatid cystic fluid at a ratio of 4:1 was a good preservative solution which kept the protoscolices viable for 15 days.