[Study of lesional aspects of hydatid echinococcosis in man in Mauritania: fertility, histology of hydatid cysts and protoscolex viability]

Viability predictive factors of the daughter vesicles in hepatic cystic echinococcosis

INTRODUCTION

Management of cystic echinococcosis (CE) requires knowledge of certain aspects related to the survival of Echinococcus granulosus. The viability of daughter vesicles (DV) is a determining factor in guiding therapeutic indications, particularly for transiently active Cysts type CE3b.

PURPOSE

To determine the predictive factors of DV viability and its impact on the therapeutic management of CE3b type.

MATERIALS AND METHODS

This is a prospective pilot study with an analytical aim on patients with cystic echinococcosis of the liver type CE2 and CE3b, operated in the General Surgery Department of Habib-Bourguiba Academic Hospital, Sfax-Tunisia for 22 months from March 2018 until December 2019. The unit of the study is the DV. A parasitological study of the DV was done in the parasitology laboratory.

RESULTS

During the study period, 27 (40.9%) of 66 operated CE Disease from 21 patients containing 248 DV were explored. The median viability of DV protoscoleces was 16.7%. In bivariate analysis, factors for viability of DV protoscoleces were: fever, acute cholangitis, hyperbilirubinemia, left liver location, rock water and bilious echinococcal fluid (EF), cyst size ≥ 43 mm, Intracystic pressure ≥ 35 mmHg, DV size ≥ 6.5 mm, volume, number of DV/cyst ≥ 5, and opaque wall (p < 0.05). Predictive factors for the Non-viability of DV were: CE3b type, purulent EF, gelatinous EF. In multivariate analysis, only CE2 type, cyst size ≥ 43 mm, number of DV/cyst ≥ 5 and DV size ≥ 6.5 mm were factors significantly associated with the viability of DV protoscoleces.

CONCLUSION

CE3b cysts without the criteria of viability of DV protoscoleces may become candidates for the 'Wait-and-Watch' procedure.

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.

New insights of the local immune response against both fertile and infertile hydatid cysts

BACKGROUND

Cystic echinococcosis is caused by the metacestode of the zoonotic flatworm Echinococcus granulosus. Within the viscera of the intermediate host, the metacestode grows as a unilocular cyst known as hydatid cyst. This cyst is comprised of two layers of parasite origin: germinal and laminated layers, and one of host origin: the adventitial layer, that encapsulates the parasite. This adventitial layer is composed of collagen fibers, epithelioid cells, eosinophils and lymphocytes. To establish itself inside the host, the germinal layer produces the laminated layer, and to continue its life cycle, generates protoscoleces. Some cysts are unable to produce protoscoleces, and are defined as infertile cysts. The molecular mechanisms involved in cyst fertility are not clear, however, the host immune response could play a crucial role.

METHODOLOGY/PRINCIPAL FINDINGS

We collected hydatid cysts from both liver and lungs of slaughtered cattle, and histological sections of fertile, infertile and small hydatid cysts were stained with haematoxylin-eosin. A common feature observed in infertile cysts was the disorganization of the laminated layer by the infiltration of host immune cells. These infiltrating cells eventually destroy parts of laminated layer. Immunohistochemical analysis of both parasite and host antigens, identify these cells as cattle macrophages and are present inside the cysts associated to germinal layer.

CONCLUSIONS/SIGNIFICANCE

This is the first report that indicates to cell from immune system present in adventitial layer of infertile bovine hydatid cysts could disrupt the laminated layer, infiltrating and probably causing the infertility of cyst.

[Parasitological study of 78 cases of human cystic echinococcosis collected between 2005 to 2012 in Mustapha hospital center of Algiers]

AIM

The aim of this work is to know the fertility rate of the metacestodes resulting from patients suffering from hydatidosis, the one of protoscoleces's viability and by comparing the results obtained with those found elsewhere. It reports, also, the epidemiological, clinical and diagnostically aspects of the studied patients.

MATERIALS AND METHODS

This study has carried on 78 hydatics samples resulting from 78 patients collected between 2005 and 2012 at the laboratory of parasitology of the Mustapha hospital center of Algiers. A questionnaire on the epidemiological context (contact with an animal-host of the cycle, place of residence, presence of family cases reached of hydatidosis and knowledge on the hydatic disease) concerned 69 patients. For each sample, a direct microscopic examination is made with or without vital staining. The presence of protoscoleces made qualified the fertile cyst. Those visualized moving or resistant to eosin at 0.2% are considered viables. Indirect diagnosis is based on the techniques: passive hemagglutination, electrophoresis, Elisa IgG Echinococcus granulosus and immunoblotting IgG "Echinococcus". Molecular analysis is based on PCR and sequencing the partials fragments of two mitochondrial genes with the primers COX1 and ND1.

RESULTS

The results obtained show that the surgical frequency of hydatidosis is significant at the young adult and at the child. The epidemiological context associated at the disease is the conjointly presence of a dog and herbivores. The fertility rate of human hydatid cysts is 88.4% and the ones of viability of the protoscoleces is 74.5%. In this series, the serology shows global positivity at 70%. The molecular characterization of five samples identify the species: E. granulosus ss.

CONCLUSION

Finally, the viability and fertility rates found here are raised. Sometimes viables protoscoleses are found after use of scolicidal solution. In front of these results, the parasitical treatment is more than necessary in order to minimize the risk of occurred of secondary echinococcosis or the relapses postoperatives.