Alveolar echinococcosis of the liver: a parasitic disease in search of a treatment

Approaches to reconstruction of inferior vena cava by ex vivo liver resection and autotransplantation in 114 patients with hepatic alveolar echinococcosis

BACKGROUND

Hepatic alveolar echinococcosis (AE) is most commonly found in retrohepatic inferior vena cava (RHIVC). Ex vivo liver resection and autotransplantation (ELRA) can better realize the radical resection of end-stage hepatic AE with severely compromised hepatocaval confluences, and reconstruction of the affected vessels. Currently, there is a scarcity of information regarding RHIVC reconstruction in ELRA.

AIM

To propose reasonable RHICV reconstruction strategies for ex vivo liver resection and autotransplantation.

METHODS

We retrospectively summarized the clinical data of 114 patients diagnosed with hepatic AE who treated by ELRA in our department. A total of 114 patients were divided into three groups according to the different reconstruction methods of RHIVC: Group A with original RHIVC being repaired and reconstructed (n = 64), group B with RHIVC being replaced (n = 43), and group C with RHIVC being resected without reconstruction (n = 7). The clinical data of patients, including the operation time, anhepatic phase, intraoperative blood loss, complications and postoperative hospital stay, were analyzed and the patients were routinely followed up. The normally distributed continuous variables were expressed as means ± SD, whereas the abnormally distributed ones were expressed as median and analyzed by analysis of variance. Survival curve was plotted by the Kaplan-Meier method.

RESULTS

All patients were routinely followed up for a median duration of 52 (range, 12-125) mo. The 30 d mortality rate was 7.0% (8/114) and 7 patients died within 90 d. Among all subjects, the inferior vena cava (IVC)-related complication rates were 17.5% (11/63) in group A and 16.3% (7/43) in group B. IVC stenosis was found in 12 patients (10.5%), whereas thrombus was formed in 6 patients (5.3%). Twenty-two patients had grade III or higher complications, with the complication rates being 17.2%, 16.3%, and 57.1% in the three groups. The average postoperative hospital stay in the three groups was 32.3 ± 19.8, 26.7 ± 18.2, and 51.3 ± 29.4 d (P = 0.03), respectively.

CONCLUSION

ELRA can be considered a safe and feasible option for end-stage hepatic AE patients with RHIVC infiltration. The RHIVC reconstruction methods should be selected appropriately depending on the defect degree of AE lesions in IVC lumen. The RHIVC resection without any reconstruction method should be considered with caution.

A Sarcopenia-Based Prediction Model for Postoperative Complications of ex vivo Liver Resection and Autotransplantation to Treat End-Stage Hepatic Alveolar Echinococcosis

Background

Sarcopenia and visceral adiposity have been shown to be associated with postoperative complications in numerous diseases. However, their effects on the postoperative complications of end-stage hepatic alveolar echinococcosis (HAE) patients undergoing ex vivo liver resection and autotransplantation (ELRA) remain unclear.

Methods

This retrospective study included 101 end-stage HAE patients who underwent ELRA from January 2014 to August 2020. We measured the skeletal muscle and adipose tissue of all patients at the level of the third lumbar vertebra on plain abdominal computed tomography (CT) images and subsequently derived an equation via least absolute shrinkage and selection operator (LASSO) regression analysis to calculate the sarcopenia score. Univariate and multivariate regression were performed to reveal the relationship between major postoperative complications and perioperative clinical data, and the obtained nomogram was validated with the bootstrapping method.

Results

The sarcopenia score was constructed as a personalized indicator to evaluate sarcopenia and visceral adiposity in each patient. Logistic regression analysis finally selected duration from primary diagnosis to obvious symptoms (OR=1.024, 95% CI, 1.007-1.042), surgical time (OR=1.003, 95% CI, 0.999-1.007) and sarcopenia score (OR=4.283, 95% CI, 1.739-10.551) as independent risk factors for predicting major postoperative complications following ELRA for end-stage HAE patients. The area under the receiver operating characteristic curve (AUROC) of 0.807 (95% CI, 0.720-0.895) and the calibration curve for this prediction model were satisfactory.

Conclusion

The sarcopenia score, which systematically evaluates the skeletal muscle and adipose tissue of end-stage HAE patients, was a significant predictive factor for major postoperative complications of ELRA. Relevant interventions should be conducted for those who have a high risk of postoperative complications according to the nomogram.

Application of ex vivo liver resection and autotransplantation in treating Budd-Chiari syndrome secondary to end-stage hepatic alveolar echinococcosis: A case series

BACKGROUND

Secondary Budd-Chiari syndrome (BCS) occurs due to a blockage in the liver caused by invasion or compression by a large lesion. Conventional treatments for BCS do not solve practical problems, wherease liver transplantation has been only applied as a last-resort therapy and as the only opportunity for a radical cure. We explored the feasibility of applying ex vivo liver resection and autotransplantation (ELRA) for the new indications of treating patients with end-stage hepatic alveolar echinococcosis (HAE). Our center has firstly proposed the idea and successfully treated the 49 patients with HAE. This article for the first time reports the application of ELRA in treating patients with BCS secondary to HAE.

METHODS

According to the degree of lesion invasion and surgical options, 11 patients were divided into 4 types. These 11 patients had large lesions that invaded the second and third hilum of the caudate lobe and involved the confluence of the hepatic vein and the inferior vena cava, suprahepatic vena cava, or at least 2 hepatic veins and led to secondary BCS. The aim of the present work was to report 11 patients with life-threatening diseases who underwent ELRA (ex vivo liver resection and autotransplantation) for secondary BCS, to propose a classification system for secondary BCS, and to suggest that secondary BCS is an indication for ELRA.

RESULTS

Eleven patients successfully underwent ELRA without intraoperative mortality. The median autograft weight was 690 g (440-950 g); operative time was 12.5 hours (9.4-16.5 hours); Postoperative hospital stay was 15 days (7-21 days). Clavien-Dindo grade IIIa or higher postoperative complications occurred in only 5 patients.

CONCLUSIONS

This article for the first time reports the application of ELRA in treating patients with BCS secondary to HAE, not only provides new ideas for alternative treatments of secondary BCS, but also provides a classification system for secondary BCS. This article describes the technical process of outflow tract reconstruction and the experience for expanding the indications for ELRA. Our study demonstrated that ELRA is well feasible for treatment of BCS secondary to advanced HAE.

A new sarcopenia score prognostic for postoperative complications in hepatic alveolar echinococcosis: a multicenter retrospective study

Background

Skeletal muscle depletion and excessive visceral adipose tissue have been shown to be independent risk factors for postoperative complications (PCs) in various diseases. However, their impact on surgical PCs in hepatic alveolar echinococcosis (HAE) is still unknown.

Methods

We retrospectively reviewed the clinical data of HAE patients who underwent liver resection at our hospital between January 2008 and December 2018. We segmented skeletal muscle and adipose tissue and measured the area of skeletal muscle tissue and adipose tissue at the level of the third lumbar vertebra by manual tracing from preoperative plain computed tomography (CT) images. Sarcopenia features were selected to construct a formula based on the least absolute shrinkage and selection operator (LASSO) logistic regression model in the primary set. Then, integrating the results of multiple clinicopathologic characteristics, we built a nomogram for predicting major PCs in HAE. The results were validated using bootstrap resampling and clinical data from other HAE centers in western China.

Results

The sarcopenia score is based on the personalized levels of the five features from the primary set (n=233). In the multivariate logistic analysis of the primary set, the independent factors for PCs were γ-glutamyl transferase (GGT), and surface area of hepatectomy, which were integrated into the nomogram combined with sarcopenia score. The model had a good prediction capability with a C-index of 0.84 (95% CI, 0.72–0.96). The calibration plot for the probability of PCs showed an optimal agreement between the nomogram predictions and actual observations in the primary and validation sets.

Conclusion

Our study showed that sarcopenia score was significantly correlated with PCs in patients with HAE. In addition, we constructed a prognostic nomogram for predicting complications in HAE patients after liver surgery. The nomogram displayed excellent discrimination and calibration. Improving the nutritional status and physical health of patients before surgery might reduce the incidence of postoperative complications for the high-risk patients.

Feasibility of Retrohepatic Inferior Vena Cava Resection Without Reconstruction for Hepatic Alveolar Echinococcosis

This study evaluates the feasibility of retrohepatic inferior vena cava (RHIVC) resection without reconstruction in patients with end-stage hepatic alveolar echinococcosis (AE). Four hundred and fifty-seven patients diagnosed with hepatic AE and who underwent surgical resections between January 2010 and October 2018 were retrospectively analyzed. Nine patients receiving RHIVC resection without reconstruction were included in this study. Among the patients, 5 were male and 4 female. Mean follow-up time was 64.4 months (18-95). In this series, adequate collateral circulation was formed before operation in all patients, and 7 cases underwent ex vivo liver resection and autotransplantation (ELRA) and 2 cases underwent extended right hemi-hepatectomy. Average standard liver volume, graft volume, surgical time, and anhepatic phase in ELRA group patients was 1144 ± 127 cm³, 740 ± 235 cm³, 16.8 ± 4.1 hours, and 337.4 ± 108.65 minutes respectively. Average hospital stay time for all patients was 45 ± 36.4 days. There were no intraoperative deaths. The 30-day mortality rate was 11.1%, and total mortality rate was 22.2%. Postoperative complications occurred in 4 patients. During follow-up, no relapsed AE lesions were found. RHIVC resection without reconstruction is a feasible way for hepatic AE patients with adequate collateral circulation. Careful protection of collateral venous is the key factor for successful operation.

Vascular infiltration-based surgical planning in treating end-stage hepatic alveolar echinococcosis with ex vivo liver resection and autotransplantation

BACKGROUND

For end-stage hepatic alveolar echinococcosis, insufficient guidance is available regarding surgical treatment, especially for ex vivo liver resection combined with autotransplantation. The indications for this complex surgery require further discussion.

METHOD

We reviewed 50 cases of patients who underwent ex vivo liver resection combined with autotransplantation from January 2014 to February 2018. A newly developed classification was used to describe vascular infiltration in all patients, who were divided into four groups based on anatomic lesion features and surgical patterns. The surgical planning for ex vivo liver resection combined with autotransplantation is then thoroughly discussed according to the gathered information.

RESULTS

In all patients, the length of the operation and the anhepatic phase were 735 minutes (range, 540-1,170 minutes) and 309 minutes (range, 122-480 minutes), respectively. The median remnant liver volume-to-standard liver volume ratio was 0.58 (range, 0.32-1.11). The rate of complications classified as Clavien-Dindo grade III or higher was 22% (11/50). A total of 3 postoperative deaths occurred. We identified 4 types with distinguished lesion anatomic features. Type I patients required more frequent unconventional reconstruction of the portal vein and bile duct than the other patients. Of the 6 type IV patients, 4 required modification of the surgical protocol according to intraoperative findings.

CONCLUSION

Vascular infiltration-based classification could improve the anatomic comprehension and, thus, facilitate surgical planning for ex vivo liver resection combined with autotransplantation. Through cautious evaluation of operability, liver function, and residual liver volume, together with delicate operative techniques and careful postoperative management, ex vivo liver resection combined with autotransplantation can achieve good results in the treatment of end-stage hepatic alveolar echinococcosis.

Ex Vivo Liver Resection and Autotransplantation for End-Stage Alveolar Echinococcosis: A Case Series

The role of autotransplantation in end-stage hepatic alveolar echinococcosis (AE) is unclear. We aimed to present our 15-case experience and propose selection criteria for autotransplantation. All patients were considered to have unresectable hepatic AE by conventional resection due to critical invasion to retrohepatic vena cava, hepatocaval region along with three hepatic veins, and the tertiary portal and arterial branches. All patients successfully underwent ex vivo extended right hepatectomy and autotransplantation without intraoperative mortality. The median autograft weight was 706 g (380-1000 g); operative time was 15.5 hours (11.5-20.5 hours); and anhepatic time was 283.8 minutes (180-435 min). Postoperative hospital stay was 32.3 days (12-60 days). Postoperative complication Clavien-Dindo grade IIIa or higher occurred in three patients including one death that occurred 12 days after the surgery due to acute liver failure. One patient was lost to follow-up after the sixth month. Thirteen patients were followed for a median of 21.6 months with no relapse. This is the largest reported series of patients with end-stage hepatic AE treated with liver autotransplantation. The technique requires neither organ donor nor postoperative immunosuppressant. The early postoperative mortality was low with acceptable morbidity. Preoperative precise assessment and strict patient selection are of utmost importance.

Epidemiology of alveolar echinococcosis with particular reference to China and Europe

Human alveolar echinococcosis (AE), caused by the metacestode of the fox tapeworm Echinococcus multilocularis, is the most pathogenic zoonosis in temperate and arctic regions of the northern hemisphere. Prospective collection of human cases in some areas and mass screenings using ultrasound imaging and confirmation with serological techniques have markedly improved our knowledge of the epidemiology of the disease in humans during the past two decades. Transmission occurs when eggs of the tapeworm, excreted by the final hosts (usually foxes but also dogs, wolves and cats), are ingested accidentally by humans or during normal feeding by a variety of rodents and small lagomorphs. However, the species of host animals differ according to regional changes in mammalian fauna. This review mostly focuses on epidemiology of alveolar echinococcosis in those parts of the world where new and more accurate epidemiological data are now available, i.e. China and Europe, as well as on new epidemiological trends that can be suspected from recent case reports and/or from recent changes in animal epidemiology of E. multilocularis infection. The People's Republic of China (PRC) is a newly recognized focus on AE in Asia. Human AE cases were firstly recognized in Xinjiang Uygur Autonomous Region and Qinghai Provinces at the end of 1950s and infected animals were first reported from Ningxia in central China and northeast of Inner Mongolia in the 1980s. E. multilocularis (and human cases of AE) appears to occur in three areas: (1) Northeastern China (northeast focus): including Inner Mongolia Autonomous region and Heliongjiang Province (2) Central China (central focus): including Gansu Province, Ningxia Hui Autonomous Region, Sichuan Province, Qinghai Province and Tibet Autonomous Region and (3) Northwestern China: including Xinjiang Uygur Autonomous Region, bordered with Mongolia, Russia, Kazakhstan and Kyrgyzstan. The highest prevalence of the disease, up to 15 per cent of the population in some villages, is reached in China. In Europe, data from the European Echinococcosis Registry (EurEchinoReg: 1982-2000) show 53 autochthonous cases of AE in Austria, 3 in Belgium, 235 in France, 126 in Germany, 1 in Greece, and 112 in Switzerland, and 15 'imported' cases, especially from central Asia; 14 cases were collected in Poland, a country not previously considered endemic for AE. Improved diagnostic technology, as well as a real increase in the infection rate and an extension to new areas, can explain that more than 500 cases have been reported for these 2 decades while less than 900 cases were published for the previous 7 decades. New epidemiological trends are related to an unprecedented increase in the fox population in Europe, to the unexpected development of urban foxes in Japan and in Europe, and to changes in the environmental situation in many countries worldwide due to climatic or anthropic factors which might influence the host-predator relationship in the animal reservoir and/or the behavioural characteristics of the populations in the endemic areas.

Immunoblot evaluation of the species-specificity of Em18 and Em16 antigens for serodiagnosis of human alveolar echinococcosis

An immunoblot study to confirm the species-specificity of the diagnostic antigens Em18 and Em16 of Echinococcus multilocularis protoscolex extract showed that both antigens cross-reacted with sera from cystic echinococcosis (CE) patients. The 18 kDa component was detectable by 75% of the sera from active alveolar echinococcosis (AE) patients, while only 31% detected Em16. Western blot analysis also showed that AE sera recognized a band in the 18 kDa region of E. granulosus protoscolex extract, which was different from the 16/17 kDa subunit of antigen B. The results suggested that Em18 antigen is present in E. granulosus as well as E. multilocularis, and that some CE patients may have serum antibody against this antigen.

Analysis of immunoglobulin G subclass in the serum antibody responses of alveolar echinococcosis patients after surgical treatment and chemotherapy as an aid to assessing the outcome

Immunoglobulin G (IgG) subclass-specific antibody responses were evaluated for the follow-up of alveolar echinococcosis (AE) patients. Seventy-four sequentially collected sera from 25 Chinese and French AE cases who underwent surgery including hepatectomy, liver transplant and/or chemotherapy were analysed quantitatively and qualitatively during the clinical follow-up period. These AE patients were classified in 4 groups--cured, improved, stabilized, or aggravated. Serum antibody levels of the subclasses IgG1 and IgG4 were significantly higher in the AE patients than in healthy controls. IgG1 and IgG4 isotypes in AE patients were the most sensitive IgG antibody response in an enzyme-linked immunosorbent assay (ELISA) and in binding to antigens of 44kDa, 35kDa, 21kDa and 17.5kDa in an Echinococcus multilocularis protoscolex extract after Western blotting. In AE cases classed as cured or improved, IgG subclass antibody levels tended to decrease earlier than total IgG levels, especially IgG4 antibody levels which became negative within one year after successful treatment. IgG4 antibody levels also decreased in most of the improved cases. Increasing or unchanged levels of IgG4 and IgG1 antibodies were demonstrated in both stabilized and aggravated AE cases using both ELISA and immunoblot assays. Reappearance of specific IgG4 antibodies was a strong indication of recurrence, especially in liver transplant patients. Combined quantitative and qualitative assessment of IgG1 and IgG4 antibodies may be potentially useful for the serological follow-up of human AE.

Immunoblot evaluation of IgG and IgG-subclass antibody responses for immunodiagnosis of human alveolar echinococcosis

Antigen binding of total-IgG and IgG-subclass antibodies from patients with alveolar or cystic echinococcosis (AE and CE) was assessed by immunoblotting. Antigen extracts were prepared from Echinococcus multilocularis protoscoleces (EmP) or from homogenized E. multilocularis metacestode tissue (EmCH). Antigens of approximately 44, 35, 21, 17.5 and 16.5 were recognized by total-IgG and IgG1- and IgG4-subclass antibodies in some of 50 human AE sera from China, Japan or France. The 44- and 35-kDa polypeptides, present in both EmP and EmCH extracts, were recognized by total-IgG antibodies in sera from 82% and 66% of the AE patients, respectively. However, over 30% cross-reactivity occurred between these two antigens and sera from CE and Taenia solium cysticercosis patients. The immunoblot specificities of the 27-, 21- and 17.5-kDa antigens in EmP for E. multilocularis infection were 73%, 88% and 93%, respectively. Recognition of the 17.5-kDa antigen in the EmP immunoblot was much higher for the Japanese AE cases (11/13; 85%) than for the French (9/19; 47%) or Chinese (9/18; 50%) AE cases. None of the CE cases from Uruguay or Libya, where human AE has not been reported, was seropositive for the 17.5-kDa antigen. Antibodies from three (7.3%) of the 41 Chinese CE cases recognized the 17.5-kDa antigen. Within the 13 Japanese AE sera, the combined detection by IgG1, IgG4 and total-IgG antibodies of the 27-, 21- and 17.5-kDa antigens in either EmP or EmCH immunoblots was greater than that by each class/subclass alone, increasing the overall sensitivity for AE patients. A combined ELISA/immunoblot approach, including IgG-subclass detection using E. multilocularis protocolex or cyst extracts, could be useful for the differential diagnosis of human alveolar echinococcosis. An algorithm for such an approach is given.

Metabolism ofD-[1-13C]glucose in livers ofMeriones unguiculatusinfected withEchinococcus multilocularis

Following administration of [1-13C]glucose, sequential13C nuclear magnetic resonance (NMR) in situ spectra were obtained from the liver of uninfected jirds (Meriones unguiculatus) and those infected with Echinococcus multilocularis over a period of 2 h. Quantitative evaluation of the flow of labelled carbon through the liver at 80 and 120 min after glucose administration revealed that although the percentage of labelled glucose utilized by the liver was the same for both groups, glycogen synthesis differed. At both times, the livers of infected animals had incorporated a smaller percentage of the [1-13C]glucose into glycogen labelled at C1and a larger percentage into the C6position of glucose/glycogen. In another experiment, identical with respect to the substrate administered, NMR analysis of perchloric acid extracts revealed that the livers of infected animals had lower concentrations of labelled glucose and glycogen and higher concentrations of labelled alanine and lactate than those of uninfected controls. Concentration differences were also noted for some of the unlabelled metabolites. Echinococcus multilocularis cysts contained the same labelled metabolites as the livers but the concentration of lactate was much higher. Parasite cysts also contained labelled acetate.

Albendazole chemotherapy for human cystic and alveolar echinococcosis in north-western China

Human echinococcosis is highly endemic in north-western China; the main treatment is by surgery. In this paper, we report the results of chemotherapy with albendazole (ABZ), 15-20 mg/kg/d orally, for 30 d with intervals of 10 d between treatments for 3-6 courses. For multi-organ cystic echinococcosis (CE) and alveolar echinococcosis (AE), patients were given 12-18 courses of ABZ. Patients were divided into 4 groups: (i) ABZ surgery group, albendazole with surgery for 21 CE cases: (ii) non-ABZ surgery group, 80 CE cases treated by surgery alone; (iii) ABZ CE group, albendazole treatment alone in 58 CE cases, and (iv) ABZ AE group, 14 AE patients treated by albendazole and surgical intervention and 5 AE patients treated by albendazole alone. Twenty-seven of 34 (79.4%) cysts in group (i) patients showed increased necrotic changes and decreased viability of the cysts compared to group (ii). However, 10 of 84 (11.9%) cysts in group (ii) patients showed spontaneous evidence of necrosis at surgery. In group (iii), ABZ treatment alone was successful in 14 (24.1%), resulted in improvement in 29 (50%) and had no effect in 15 (25.9%) patients. Seven cases in group (iv) improved, with diminished size of lesions which were non-viable. The remaining 7 cases in group (iv) showed evidence of cyst viability at surgery; 2 could not be saved after a further 15 courses of albendazole. Of the five AE patients in group (iv) who received only ABZ, one improved, 2 stabilized, one deteriorated and one died. Albendazole chemotherapy, while not completely effective, has an important role in treatment of both cystic and alveolar echinococcosis.

The efficacy of chemotherapy with mebendazole in human cystic echinococcosis: long-term follow-up of 52 patients

Sixty patients with Echinococcus granulosus infection of the liver, lungs, bone and/or soft tissues were treated for several months with oral mebendazole (50-60 mg kg-1 day-1), in divided doses after fat-rich meals, either without surgery (WS), post-surgery (PS) or pre- and post-surgery (PPS). Long-term follow-up, possible for 52 of the patients, showed that WS, PS and PPS patients have so far remained disease-free following treatment for (means +/- standard deviations) 65.5 +/- 37.7, 82.5 +/- 37.0 and 84.1 +/- 28.3 months, respectively. Ultrasound and computed tomography scans were similar in WS and PPS patients post-treatment. Blood eosinophil levels, which were sometimes elevated initially, returned to normal in all patients and this decrease indicated cyst degeneration before this was evident on the scans. Treatment of patients with cystic echinococcosis may no longer require surgery.

Hydroxypyridinium collagen cross-links in human liver fibrosis: study of alveolar echinococcosis

Liver samples from patients with three different types of liver diseases, alveolar echinococcosis (a dense and irreversible fibrosis), hepatocellular carcinoma and alcoholic cirrhosis, were analyzed for their content in hydroxypyridinium cross-links found in mature collagen. We demonstrated the presence of small amounts of pyridinoline in control livers (0.27 +/- 0.06 pmol/pmol of collagen). Pyridinoline content was increased in fibrotic livers, with the highest values found in patients with alveolar echinococcosis (up to 1.33 pmol/pmol of collagen). The deoxy analogue of pyridinoline was not detected in either normal or fibrotic livers. Pyridinoline levels, expressed as picomoles per picomole of collagen, were similar in all patients with carcinoma (0.7 +/- 0.05 pmol/pmol of collagen). They were heterogeneous in patients with alveolar echinococcosis and were particularly high in patients with alcoholic cirrhosis (1.04 +/- 0.11 pmol/pmol of collagen). These results demonstrate for the first time the presence of an hydroxypyridinium cross-link in liver fibrosis and suggest that pyridinoline measurement might be an important criterion in assessing the irreversibility of human liver fibrosis.

Effects of cyclosporin A on the course of murine alveolar echinococcosis and on specific cellular and humoral immune responses against Echinococcus multilocularis

The effects of cyclosporin A (CsA) on Echinococcus multilocularis (E. multilocularis) metacestode growth, and on the specific immune responses of the hosts, were examined in AKR mice. Mice were intra-peritoneally infected with a metacestode homogenate. CsA (40 mg kg(-1) day(-1)) was injected subcutaneously from the 45th day after infection (Group 1), and from the day before infection (Group 2) until the day of autopsy (days 125 and 80, respectively). Results showed that unlike ths situation with some other helminthiases, CsA had no antiparasitic effect, although it lengthened the maturation time of protoscoleces in Group 1. The parasitic burden, unmodified in Group 1, was significantly enhanced in Group 2. This enhancement was associated with a decrease in antibody levels, whereas the delayed-type hypersensitivity was decreased in the two groups. These results confirm the role of cellular immunity in controlling the first stages of the larval development of E. multilocularis and indicate the necessity for a careful follow-up of any recurrence of alveolar echinococcosis in patients treated with CsA after liver transplantation.