Diagnosis and treatment experience of atypical hepatic cystic echinococcosis type 1 at a tertiary center in China.

BACKGROUND: Some hydatid cysts of cystic echinococcosis type 1 (CE1) lack well-defined cyst walls or distinctive endocysts, making them difficult to differentiate from simple hepatic cysts. AIM: To investigate the diagnostic methods for atypical hepatic CE1 and the clinical efficacy of laparoscopic surgeries. METHODS: The clinical data of 93 patients who had a history of visiting endemic areas of CE and were diagnosed with cystic liver lesions for the first time at the People's Hospital of Xinjiang Uygur Autonomous Region (China) from January 2018 to September 2023 were retrospectively analyzed. Clinical diagnoses were made based on findings from serum immunoglobulin tests for echinococcosis, routine abdominal ultrasound, high-frequency ultrasound, abdominal computed tomography (CT) scan, and laparoscopy. Subsequent to the treatments, these patients underwent reexaminations at the outpatient clinic until October 2023. The evaluations included the diagnostic precision of diverse examinations, the efficacy of surgical approaches, and the incidence of CE recurrence. RESULTS: All 93 patients were diagnosed with simple hepatic cysts by conventional abdominal ultrasound and abdominal CT scan. Among them, 16 patients were preoperatively diagnosed with atypical CE1, and 77 were diagnosed with simple hepatic cysts by high-frequency ultrasound. All the 16 patients preoperatively diagnosed with atypical CE1 underwent laparoscopy, of whom 14 patients were intraoperatively confirmed to have CE1, which was consistent with the postoperative pathological diagnosis, one patient was diagnosed with a mesothelial cyst of the liver, and the other was diagnosed with a hepatic cyst combined with local infection. Among the 77 patients who were preoperatively diagnosed with simple hepatic cysts, 4 received aspiration sclerotherapy of hepatic cysts, and 19 received laparoscopic fenestration. These patients were intraoperatively diagnosed with simple hepatic cysts. During the follow-up period, none of the 14 patients with CE1 experienced recurrence or implantation of hydatid scolices. One of the 77 patients was finally confirmed to have CE complicated with implantation to the right intercostal space. CONCLUSION: Abdominal high-frequency ultrasound can detect CE1 hydatid cysts. The laparoscopic technique serves as a more effective diagnostic and therapeutic tool for CE.

The application of laparoscopy combined with indocyanine green fluorescence imaging technique for hepatic cystic echinococcosis.

BACKGROUND: With the mature application of laparoscopy in hepatobiliary surgery, laparoscopic treatment of hepatic cystic echinococcosis (CE) has made certain progress. But, due to the inherent limitations of laparoscopy and the growth characteristics of cystic echinococcosis, distinguishing the boundary between cystic lesion and normal hepatic parenchyma is pivotal importance for successful surgery. Indocyanine green (ICG) fluorescence imaging technology can view the boundary of lesion and normal tissue during the treatment of hepatic cystic echinococcosis. Applied laparoscopy combined with ICG fluorescence imaging technique for hepatic cystic echinococcosis may be an effective surgical strategy. METHODS: The clinical data contained nine patients with hepatic cystic echinococcosis who underwent laparoscopic surgery with indocyanine green fluorescence imaging technique in authors' institution from December 2018 to December 2019 were retrospectively analyzed. Indocyanine green was administered intravenously three days prior to surgery. The fluorescence acquisition system for real-time imaging was used during the surgery and the patients were followed up after surgery. RESULTS: Of reported nine patients, six are male and the remaining three are female. The average age is (36.4 ± 7.6) years. For all subjects, surgical procedures were performed under laparoscopy with indocyanine green fluorescence system. This technique showed the clear boundary of the hepatic cyst with normal liver parenchyma. Total cystectomy in six patients, subtotal cystectomy in two patients and partial hepatectomy in one patient were performed respectively. The average operation time was 3.8 ± 0.9 h, blood loss 206.0 ± 120.7 ml. Neither blood transfusion nor post-operative complication was experienced. The average abdominal drainage time was 3.4 ± 0.9 days with hospital stay 5.7 ± 2.1 days. During the 6-12 months follow-up period, neither recurrence nor intraperitoneal implantation was found. CONCLUSIONS: Applied laparoscopy combined with ICG fluorescence imaging technique for hepatic cystic echinococcosis is safe and feasible. Enhanced boundary image can assist surgeons to complete radical resection and reduce complications.

Dual Role of Hepatic Macrophages in the Establishment of the Echinococcus multilocularis Metacestode in Mice.

Echinococcus multilocularis larvae, predominantly located in the liver, cause a tumor-like parasitic disease, alveolar echinococcosis (AE), that is characterized by increased infiltration of various immune cells, including macrophages, around the lesion that produces an "immunosuppressive" microenvironment, favoring its persistent infection. However, the role of hepatic macrophages in the host defense against E. multilocularis infection remains poorly defined. Using human liver tissues from patients with AE and a hepatic experimental mouse model of E. multilocularis, we investigated the phenotype and function of hepatic macrophages during the parasite infection. In the present study, we found that a large number of CD68+ macrophages accumulated around the metacestode lesion in the liver of human AE samples and that both S100A9+ proinflammatory (M1 phenotype) and CD163+ anti-inflammatory (M2 phenotype) macrophages were significantly higher in close liver tissue (CLT) than in distant liver tissue (DLT), whereas M2 macrophages represent the dominant macrophage population. Furthermore, E. multilocularis-infected mice exhibited a massive increase in macrophage (F4/80+) infiltration in the liver as early as day 5, and the infiltrated macrophages were mainly monocyte-derived macrophages (CD11bhi F4/80int MoMFs) that preferentially differentiated into the M1 phenotype (iNOS+) at the early stage of E. multilocularis infection and then polarized to anti-inflammatory macrophages of the M2 phenotype (CD206+) at the chronic stage of infection. We further showed that elimination of macrophages by treatment of mice with clodronate-liposomes before E. multilocularis infection impaired worm expulsion and was accompanied by a reduction in liver fibrosis, yielding a high parasite burden. These results suggest that hepatic macrophages may play a dual role in the establishment and development of E. multilocularis metacestodes in which early larvae clearance is promoted by M1 macrophages while persistent metacestode infection is favored by M2 macrophages.

Thioredoxin peroxidase secreted by Echinococcus granulosus (sensu stricto) promotes the alternative activation of macrophages via PI3K/AKT/mTOR pathway.

BACKGROUND: Larvae of Echinococcus granulosus (sensu lato) dwell in host organs for a long time but elicit only a mild inflammatory response, which indicates that the resolution of host inflammation is necessary for parasite survival. The recruitment of alternatively activated macrophages (AAMs) has been observed in a variety of helminth infections, and emerging evidence indicates that AAMs are critical for the resolution of inflammation. However, whether AAMs can be induced by E. granulosus (s.l.) infection or thioredoxin peroxidase (TPx), one of the important molecules secreted by the parasite, remains unclear. METHODS: The activation status of peritoneal macrophages (PMs) derived from mice infected with E. granulosus (sensu stricto) was analyzed by evaluating the expression of phenotypic markers. PMs were then treated in vivo and in vitro with recombinant EgTPx (rEgTPx) and its variant (rvEgTPx) in combination with parasite excretory-secretory (ES) products, and the resulting activation of the PMs was evaluated by flow cytometry and real-time PCR. The phosphorylation levels of various molecules in the PI3K/AKT/mTOR pathway after parasite infection and antigen stimulation were also detected. RESULTS: The expression of AAM-related genes in PMs was preferentially induced after E. granulosus (s.s.) infection, and phenotypic differences in cell morphology were detected between PMs isolated from E. granulosus (s.s.)-infected mice and control mice. The administration of parasite ES products or rEgTPx induced the recruitment of AAMs to the peritoneum and a notable skewing of the ratio of PM subsets, and these effects are consistent with those obtained after E. granulosus (s.s.) infection. ES products or rEgTPx also induced PMs toward an AAM phenotype in vitro. Interestingly, this immunomodulatory property of rEgTPx was dependent on its antioxidant activity. In addition, the PI3K/AKT/mTOR pathway was activated after parasite infection and antigen stimulation, and the activation of this pathway was suppressed by pre-treatment with an AKT/mTOR inhibitor. CONCLUSIONS: This study demonstrates that E. granulosus (s.s.) infection and ES products, including EgTPx, can induce PM recruitment and alternative activation, at least in part, via the PI3K/AKT/mTOR pathway. These results suggest that EgTPx-induced AAMs might play a key role in the resolution of inflammation and thereby favour the establishment of hydatid cysts in the host.