Monoclonal antibody-based localization of major diagnostic antigens in metacestode tissue, excretory/secretory products, and extracellular vesicles of Echinococcus species

Histopathological assessment of the viability of hepatic alveolar echinococcosis

AIMS

Infections by the larval stage of the tape worms Echinococcus multilocularis and Echinococcus granulosus s.l. are potentially fatal zoonoses affecting humans as dead-end hosts. Histopathological evaluation of hepatic echinococcosis is an integral part of patient management, including the distinction between alveolar (AE) and cystic echinococcosis (CE), which are associated with different disease courses and treatments. To improve histopathological assessment of Echinococcus lesions, we aimed to develop robust criteria to evaluate their viability and decay.

METHODS AND RESULTS

Histomorphological criteria for determining parasitic viability based on the morphology of parasite structures and different stages of their decay were defined based on a clinically and molecularly defined cohort comprising 138 specimens from 112 patients (59 AE and 53 CE); 618 AE lesions were assessed for histopathological viability comparing haematoxylin and eosin (H&E) staining with mAbEm18 and mAbEm2G11 immunostaining. Moreover, parasite viability was systematically mapped in cross-sections of five additional AE lesions. Protoscoleces in CE and AE displayed variable states of degeneration. Albendazole had no significant effect on the morphology of parasite structures. Viability assessment revealed high agreement between H&E and mAbEm18, but not mAbEm2G11 staining, suggesting mAbEm18 staining as reliable for parasite viability assessment. H&E and mAbEm18 staining displayed a central-peripheral gradient of parasite viability and decay across parasitic lesions, with decayed cystic lesions located more towards the lesion centre while the most viable cystic lesions were located more peripherally.

CONCLUSIONS

Histopathological criteria corroborated by mAbEm18 staining provide a simple and reliable tool to assess the viability of AE lesions, knowledge of which is a valuable decision-making tool for further treatment.

Benzaldehyde stimulates autophagy via the sonic hedgehog signaling pathway in mouse brain astrocytes after treatment with Angiostrongylus cantonensis excretory-secretory products

Autophagy is a vital cellular process responsible for digesting various cytoplasmic organelles. This process plays a crucial role in maintaining cell survival and homeostasis, especially under conditions that cause nutrient deficiency, cellular damage, and oxidative stress. Neuroangiostrongyliasis is an infection caused by the parasitic nematode Angiostrongylus cantonensis and is considered as an emerging disease in many parts of the world. However, effective therapeutic strategies for neuroangiostrongyliasis still need to be further developed. In this study, we investigated the effects of benzaldehyde treatment on autophagy and sonic hedgehog (Shh) signaling in A. cantonensis-infected mice and its mechanisms. First, we found autophagosome generation in the central nervous system after A. cantonensis infection. Next, benzaldehyde combined with albendazole treatment reduced eosinophilic meningitis and upregulated the expression of Shh signaling- and autophagy-related molecules in A. cantonensis-infected mouse brains. In vitro experiments demonstrated that benzaldehyde could induce autophagy via the Shh signaling pathway in A. cantonensis excretory-secretory products (ESPs)-treated mouse astrocytes. Finally, benzaldehyde treatment also decreased lipid droplet accumulation and increased cholesterol production by activating the Shh pathway after ESPs treatment. In conclusion, these findings suggested that benzaldehyde treatment could alleviate brain damage by stimulating autophagy generation through the Shh signaling pathway.

Immunohistochemistry as a Reliable Tool for the Diagnosis of Cystic Echinococcosis in Patients from Sardinia, Italy-A Confirmatory Study

Cystic Echinococcosis (CE) is a zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus sensu lato (s.l.). This study aims to investigate the use of two monoclonal antibodies (mAbEmG3 and mAbEm2G11) by immunohistochemistry (IHC) to confirm the diagnosis of CE in human patients, in particular in those cases in which other techniques fail to provide a correct or conclusive diagnosis. For this purpose, a survey on 13 patients was performed. These subjects were referred to Sardinian hospitals (Italy) from 2017 to 2022 and were suspected to be affected by CE. Our findings from these 13 patients showed the detection of E. granulosus sensu stricto by IHC in 12 of 13 echinococcal cysts, as one sample was of a non-parasitological origin. The results confirmed that IHC, by means of the mAbEmG3 and mAbEm2G11, is a reliable diagnostic tool that showed a very high performances when tested on strain of E. granulosus s.l. from Sardinia.

Serological Comparison of Native Antigen ELISAs with Rapid ICT Test Kits for the Diagnosis of Human Alveolar and Cystic Echinococcosis in China

BACKGROUND

The aim of this study was to compare the diagnostic performance of native antigen ELISAs and ADAMU-AE/CE commercial ICT test kits in subjects either exposed to Echinococcus infection or with clinically diagnosed alveolar (AE) or cystic (CE) echinococcosis.

METHODS

A total of 370 subjects with a previous clinical confirmation of CE or AE from northwestern China were recruited. Serum samples were also obtained from 3923 children/teenagers during a community survey. All sera were tested using native antigen ELISAs. The ADAMU-AE/CE test kits were subsequently used for the serology of the 370 clinically confirmed individuals and of 251 children/teenagers that were ELISA antibody-positive for both Echinococcus species but ultrasound-negative during baseline survey. An analysis of the association between the serological tests and ultrasound classification was carried out amongst 89 AE and 164 CE cases. A Kappa consistency analysis was undertaken to compare the diagnostic performance of the native antigen ELISAs and the ADAMU kits and the ultrasound imaging results. The χ² test was also used for a comparison of the different seropositivity rates between the groups.

FINDINGS

There was poor consistency (Kappa = 0.26 and 0.28 for AE and CE respectively) between the native antigen ELISAs and the ADAMU kits for the diagnosis of AE and CE among the cases and the surveyed children/teenagers, but a relatively good consistency (Kappa = 0.63) between the ADAMU-AE kit and ultrasound observations for the AE cases. Additionally, of the 251 teenagers co-positive for both AE and CE antibodies by the native antigen ELISAs, only one was found positive by the ADAMU-AE kit, verified as a new AE case on subsequent ultrasound follow-up. The remainder (N = 250) were negative by serology using the ADAMU-AE/CE kits and by ultrasound examination. The two native antigen ELISAs did not discriminate well between cases of clinically diagnosed AE and CE. In contrast, ADAMU-AE and ADAMU-CE commercial ICT test kits readily differentiated cases of AE from CE with specificities of 99% for AE and 100% for CE.

CONCLUSIONS

The ADAMU-AE/CE kits proved reliable, accurate, and amenable diagnostic tools in the clinical setting for confirmation of suspected AE/CE cases. The native antigen ELISAs tests can provide useful information on the level of human exposure to Echinococcus infection.