[Échinococcose alvéolaire]. / Alveolar echinococcosis.

Alveolar echinococcosi. Alveolar echinococcosis is a parasitic anthropo-zoonosis which looks like a slow-growing liver cancer. The lesions progressively obstruct hepatic vessels and bile ducts and invade neighboring organs, and it may metastasize to the lung and the brain and possibly all distant organs. Since the 1990s earlier diagnosis by imaging, advances in surgical and less invasive interventions, and prolonged anti-parasitic treatment using albendazole, have totally transformed the prognosis of the disease. However, in Europe, the endemic area has considerably increased, the number of alveolar echinococcosis cases has more than doubled in the previously identified endemic regions, and the disease may now be considered to be an 'opportunistic infection', especially diagnosed in those patients treated with immunosuppressive drugs and biologic agents. Alveolar echinococcosis is currently more and more often diagnosed incidentally, at an early stage of development, and not in the usual 'at risk' regions and populations. This makes differential diagnosis and care management more challenging.

Échinococcose alvéolaire. L'échinococcose alvéolaire est une anthropozoonose parasitaire qui se comporte comme un cancer du foie d'évolution lente. Les lésions envahissent de proche en proche les axes vasculaires et biliaires et les organes de voisinage et sont capables de métastaser, le plus souvent vers le poumon et le cerveau mais potentiellement aussi vers tous les organes. Depuis les années 1990, les progrès en imagerie, l'utilisation judicieuse de la chirurgie et des interventions non chirurgicales et le traitement antiparasitaire par albendazole au long cours ont transformé le pronostic de l'infection. Cependant, en Europe, la zone d'endémie s'est considérablement étendue, le nombre de cas a plus que doublé dans les zones d'endémie « traditionnelles ¼, et la maladie peut maintenant être comptée parmi les infections « opportunistes ¼, touchant tout particulièrement les patients traités par des médicaments ou des agents biologiques immunosuppresseurs. La découverte accidentelle de lésions à la phase précoce d'évolution, et de plus en plus fréquemment hors des zones et des populations habituellement considérées à risque, pose actuellement des problèmes difficiles de diagnostic différentiel et de nouveaux défis pour la prise en charge thérapeutique.

Gastrointestinal stromal tumours (GISTs): French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO).

BACKGROUND: This document is a summary of the French Intergroup guidelines regarding the management of gastrointestinal stromal tumours (GISTs) updated in December 2018. DESIGN: This collaborative work summarizes clinical practice recommendations (guidelines) on the management of GISTs. It is based on recent literature review, ESMO recommendations and expert opinions. RESULTS: The diagnosis of GIST is based on histological examination and immunohistochemistry with markers KIT and DOG-1. Each case must be discussed within a multidisciplinary team. Complete surgical resection tumour, avoiding peroperative perforation, is the potentially curative treatment of localized GISTs. The estimation of the recurrence risk is essential, or adjuvant treatment,and follow-up adaptation. Genotyping (KIT and PDGFRA) of all but very low-risk GISTs is recommended. The nature of mutation has a prognostic value and predictive influence on drug efficacy. Imatinib, a tyrosine-kinase inhibitor, is the standard adjuvant treatment after R0 resection of a GIST with a high risk of recurrence, and the first line therapy for advanced GISTs. Suninitib and regorafenib are respectively the second- and third-line standard treatments for advanced GISTs. CONCLUSION: Guidelines for management of GISTs are continuously evolving and need to be regularly updated. This constant progress is made possible through clinical and translational research.

Efficacy and Safety of Two Neoadjuvant Strategies With Bevacizumab in MRI-Defined Locally Advanced T3 Resectable Rectal Cancer: Final Results of a Randomized, Noncomparative Phase 2 INOVA Study.

BACKGROUND: Recurrence and distant metastases remain a significant issue in locally advanced rectal cancer (LARC). Several multimodal strategies are assessed in clinical trials. PATIENTS AND METHODS: Patients with mid/low magnetic resonance imaging-defined high-risk LARC were randomized to arm A (12-week bevacizumab + FOLFOX-4 then bevacizumab-5-fluorouracil [5-FU]-radiotherapy [RT] before total mesorectal excision [TME]) or arm B (bevacizumab-5-FU-RT then TME). Long-term efficacy and safety up to 5 years' follow-up are reported. No comparison between arms was planned. RESULTS: Overall, 91 patients (46 in arm A and 45 in arm B) were included. Main results have been presented previously. During the late follow-up period (> 4 weeks after surgery), 4 patients (8.7%) in arm A and 4 (8.9%) in arm B experienced grade 3/4 adverse events related to bevacizumab; the most frequent were 2 anastomotic fistulas (both in arm A) and abscesses (1 in arm A and 2 in arm B). At 5 years' follow-up, 9 (19.6%) and 11 (24.4%) patients in arms A and B developed a fistula in the year after surgery, and 2 (4.3%) in arm A at > 1 year after surgery. Most resolved before study end. Five-year disease-free survival was 70% and 64.3% in arms A and B, respectively. Five-year overall survival was 90.5% (95% confidence interval, 76.7, 96.3) in arm A and 72.7% (95% confidence interval, 56.0, 83.9) in arm B. CONCLUSION: Neoadjuvant bevacizumab + FOLFOX-4 may have the potential to increase survival outcomes when followed by bevacizumab-5-FU-RT and TME in LARC. Bevacizumab-5-FU-RT then TME was associated with a higher-than-projected rate of anastomotic fistulas. Further research of neoadjuvant strategies in LARC is encouraged.

Current interventional strategy for the treatment of hepatic alveolar echinococcosis.

INTRODUCTION: The use of various types of invasive interventions combined with anti-infective drugs in the therapeutic strategy of alveolar echinococcosis (AE) has changed during the last 30 years. Areas covered: This article reviews the current respective indications of surgical, percutaneous and perendoscopic interventions in AE and proposes an integrative therapeutic strategy. Expert commentary: Hepatic resection is indicated whenever it is feasible and curative; palliative surgery should be avoided; percutaneous procedures are best adapted to the drainage of the necrotic cavity present in advanced cases; perendoscopic procedures with stenting are best adapted to alleviating the biliary complications that are common and life-threatening in AE patients. Continuous administration of albendazole or mebendazole, without interruption is mandatory in all cases, temporarily (recommended duration: 2 years) after radical lesion resection in patients without immune suppression; for life in all other cases. Long-term follow-up is essential.

Emergency surgery for intestinal obstruction revealing ileal Crohn's disease (CD) during pregnancy.

Few data are available regarding emergency surgery for Crohn's disease (CD) during pregnancy. A 22-year -old woman, at 26 weeks of pregnancy, was admitted for premature labour, intestinal obstruction and systemic inflammation. Biology and ultrasonography were not helpful; imaging was completed with a CT scan, which confirmed the mechanical ileal obstruction. The intestinal obstruction worsened and led to emergency surgery. An inflammatory stenosis of the terminal ileum with two fistulas was found. An ileal resection and ileostomy were performed. The pathological analysis of the resected specimen confirmed CD. The postoperative course was uneventful. The delivery of a baby with normal weight and status occurred at term (40 weeks of amenorrhoea). There have been only 10 case reports of intestinal complications revealing CD during pregnancy. The delay in diagnosis and adequate treatment led to significant maternal and fetal morbidity and mortality. This case suggests that intestinal surgery for CD is feasible during pregnancy and may be associated with a favourable outcome for the baby as well as for the mother.

Tumour size over 3 cm predicts poor short-term outcomes after major liver resection for hilar cholangiocarcinoma. By the HC-AFC-2009 group.

INTRODUCTION: As mortality and morbidity after a curative resection remains high, it is essential to identify pre-operative factors associated with an early death after a major resection. METHODS: Between 1998 and 2008, we selected a population of 331 patients having undergone a major hepatectomy including segment I with a lymphadenectomy and a common bile duct resection for a proven hilar cholangiocarcinoma in 21 tertiary centres. The study's objective was to identify pre-operative predictors of early death (<12 months) after a resection. RESULTS: The study cohort consisted of 221 men and 110 women, with a median age of 61 years (range: 24-85). The post-operative mortality and morbidity rates were 8.2% and 61%, respectively. The 1-, 3- and 5-year overall survival rates were 85%, 64% and 53%, respectively. The median tumour size was 23 mm on pathology, ranging from 8 to 40. A tumour size >30 mm [odds ratio (OR) 2.471 (95% confidence interval (CI) 1.136-7.339), P = 0.001] and major post-operative complication [OR 3.369 (95% CI 1.038-10.938), P = 0.004] were independently associated with death <12 months in a multivariate analysis. CONCLUSION: The present analysis of a series of 331 patients with hilar cholangiocarcinoma showed that tumour size >30 mm was independently associated with death <12 months.

A case-control study of pre-operative levels of serum neutrophil gelatinase-associated lipocalin and other potential inflammatory markers in colorectal cancer.

BACKGROUND: Chronic inflammation is a key feature of colorectal cancer (CRC), meaning that inflammatory biomarkers may be useful for its diagnosis. In particular, high neutrophil gelatinase-associated lipocalin (NGAL) expression has been reported in CRC. Thus, we investigated whether serum NGAL and NGAL/MMP-9 could be potential biomarkers for the early detection of CRC. Concurrently, we studied other inflammatory biomarkers such as soluble tumor necrosis factor receptor 1 and 2 (sTNFR-1, sTNFR-2), and C reactive protein (CRP). METHODS: The AGARIC multicenter case-control study was performed in eastern France and included patients admitted for elective surgery either for a priori non-metastatic incident CRC (n=224) or for benign causes (n=252). Pre-operative serum levels of NGAL, NGAL/MMP-9, sTNFR-1, sTNFR-2 and CRP were measured. RESULTS: Median values of serum NGAL, NGAL/MMP-9, sTNFR-1, sTNFR-2 and CRP were significantly higher in CRC patients than in controls. Receiver Operating Characteristic analysis provided relatively poor values of area under the curve, ranging from 0.65 to 0.58. Except for NGAL/MMP-9, all biological parameters were strongly correlated in CRC cases and, less strongly in controls. Multivariate odds ratio (OR) of CRC comparing the extreme tertiles of serum NGAL was 2.76 (95% confidence interval (CI): 1.59-4.78; p<0.001),. Lower but significant multivariate associations were observed for sTNFR-1, and sTNFR-2: OR=2.44 (95% CI : 1.34-4.45, p=0.015) and 1.93 (95% : CI 1.12-3.31), respectively. No independent association was found between case-control status and NGAL/MMP-9. Among CRC cases, maximal tumor size was an independent determinant of serum NGAL (p=0.028) but this association was reduced after adjustment for CRP (p=0.11). CONCLUSION: Despite a significant increase in serum NGAL and other inflammatory markers among CRC patients, our findings suggest that they may not be suitable biomarkers for the diagnosis and especially early detection of CRC.

Echinococcus ortleppi infections in humans and cattle, France.

In 2011 and 2012, liver infections caused by Echinococcus ortleppi tapeworms were diagnosed in 2 humans in France. In 2012, a nationwide slaughterhouse survey identified 7 E. ortleppi infections in cattle. The foci for these infections were spatially distinct. The prevalence of E. ortleppi infections in France may be underestimated.

Liver resection for colorectal metastases: results and prognostic factors with 10-year follow-up.

PURPOSE: Actual 5-year survival rates after resection of colorectal liver metastases (CLM) are 25-45%, whereas 10-year survival rates are extrapolated from survival curves. Few studies have reported long-term survivors with 10 years of actual follow-up. Therefore, no recurrences occurring after 10-plus years have been reported. The aim of our study was to analyze actual 10-year survival rates and prognostic factors. METHODS: Clinical data of patients with CLM who had undergone first liver resection in our center between January 1990 and December 2000 were retrospectively analyzed. RESULTS: Eighty-nine patients of mean age 64 years were studied. Three patients were excluded from the study: one because of postoperative death, and two from being lost to follow-up. All other subjects had a potential 10-year follow-up. Only 33% patients received perioperative chemotherapy. The actual 10-year overall and disease-free survival rate were 22 and 19%, respectively. Poor prognostic factors were disease-free interval less than 1 year, wedge liver resection, clinical risk score>2, segment 1 CLM location, and peritumoral lymphangitis. Good prognostic factors were tumors having mucinous components in primary tumor and CLM located in the right lobe. CONCLUSIONS: With actual long-term follow-up for 10 years, disease-free survival rate is 19% and mainly depends on surgical management. Recurrence continues to occur more than 5 years after liver resection for CLM; cure cannot be assumed at this time. Clinical risk score is a good predictor of cure and should be taken into account when choosing perioperative treatment.

Liver transplantation for neuroendocrine tumors in Europe-results and trends in patient selection: a 213-case European liver transplant registry study.

OBJECTIVE: The purpose of this study was to assess outcomes and indications in a large cohort of patients who underwent liver transplantation (LT) for liver metastases (LM) from neuroendocrine tumors (NET) over a 27-year period. BACKGROUND: LT for NET remains controversial due to the absence of clear selection criteria and the scarcity and heterogeneity of reported cases. METHODS: This retrospective multicentric study included 213 patients who underwent LT for NET performed in 35 centers in 11 European countries between 1982 and 2009. One hundred seven patients underwent transplantation before 2000 and 106 after 2000. Mean age at the time of LT was 46 years. Half of the patients presented hormone secretion and 55% had hepatomegaly. Before LT, 83% of patients had undergone surgical treatment of the primary tumor and/or LM and 76% had received chemotherapy. The median interval between diagnosis of LM and LT was 25 months (range, 1-149 months). In addition to LT, 24 patients underwent major resection procedures and 30 patients underwent minor resection procedures. RESULTS: Three-month postoperative mortality was 10%. At 5 years after LT, overall survival (OS) was 52% and disease-free survival was 30%. At 5 years from diagnosis of LM, OS was 73%. Multivariate analysis identified 3 predictors of poor outcome, that is, major resection in addition to LT, poor tumor differentiation, and hepatomegaly. Since 2000, 5-year OS has increased to 59% in relation with fewer patients presenting poor prognostic factors. Multivariate analysis of the 106 cases treated since 2000 identified the following predictors of poor outcome: hepatomegaly, age more than 45 years, and any amount of resection concurrent with LT. CONCLUSIONS: LT is an effective treatment of unresectable LM from NET. Patient selection based on the aforementioned predictors can achieve a 5-year OS between 60% and 80%. However, use of overly restrictive criteria may deny LT to some patients who could benefit. Optimal timing for LT in patients with stable versus progressive disease remains unclear.

Metronomic cyclophosphamide: an alternative treatment for hepatic epithelioid hemangioendothelioma.

Hepatic epithelioid hemangioendothelioma is a rare liver mesenchymatous tumor with an epithelial aspect developed from endothelial cells with a lack of validated therapeutic options at metastatic stage. Metronomic chemotherapy has been described as an anti-angiogenic therapy leading to the depletion of circulating endothelial progenitors. We report the results of two patients treated for metastatic hemangioendothelioma with metronomic cyclophosphamide chemotherapy. Following initiation of metronomic cyclophosphamide chemotherapy (50mg once a day continuously), the two patients exhibited significant clinical improvement and decrease in metastasis size without any clinically relevant side-effect. Metronomic cyclophosphamide could be proposed as a new therapeutic option to treat metastatic hepatic epithelioid hemangioendothelioma.

TGF-ß and TGF-ß/Smad signaling in the interactions between Echinococcus multilocularis and its hosts.

Alveolar echinococcosis (AE) is characterized by the development of irreversible fibrosis and of immune tolerance towards Echinococcus multilocularis (E. multilocularis). Very little is known on the presence of transforming growth factor-ß (TGF-ß) and other components of TGF-ß/Smad pathway in the liver, and on their possible influence on fibrosis, over the various stages of infection. Using Western Blot, qRT-PCR and immunohistochemistry, we measured the levels of TGF-ß1, TGF-ß receptors, and down-stream Smads activation, as well as fibrosis marker expression in both a murine AE model from day 2 to 360 post-infection (p.i.) and in AE patients. TGF-ß1, its receptors, and down-stream Smads were markedly expressed in the periparasitic infiltrate and also in the hepatocytes, close to and distant from AE lesions. Fibrosis was significant at 180 days p.i. in the periparasitic infiltrate and was also present in the liver parenchyma, even distant from the lesions. Over the time course after infection TGF-ß1 expression was correlated with CD4/CD8 T-cell ratio long described as a hallmark of AE severity. The time course of the various actors of the TGF-ß/Smad system in the in vivo mouse model as well as down-regulation of Smad7 in liver areas close to the lesions in human cases highly suggest that TGF-ß plays an important role in AE both in immune tolerance against the parasite and in liver fibrosis.

30-yr course and favorable outcome of alveolar echinococcosis despite multiple metastatic organ involvement in a non-immune suppressed patient.

We report the 30-yr history of a well-documented human case of alveolar echinococcosis, with a lung lesion at presentation followed by the discovery of a liver lesion, both removed by surgery. Subsequently, within the 13 years following diagnosis, metastases were disclosed in eye, brain and skull, as well as additional lung lesions. This patient had no immune suppression, and did not have the genetic background known to predispose to severe alveolar echinococcosis; it may thus be hypothesized that iterative multi-organ involvement was mostly due to the poor adherence to benzimidazole treatment for the first decade after diagnosis. Conversely, after a new alveolar echinococcosis recurrence was found in the right lung in 1994, the patient accepted to take albendazole continuously at the right dosage. After serology became negative and a fluoro-deoxy-glucose-Positron Emission Tomography performed in 2005 showed a total regression of the lesions in all organs, albendazole treatment could be definitively withdrawn. In 2011, the fluoro-deoxy-glucose-Positron Emission Tomography showed a total absence of parasitic metabolic activity and the patient had no clinical symptoms related to alveolar echinococcosis.The history of this patient suggests that multi-organ involvement and alveolar echinococcosis recurrence over time may occur in non-immune suppressed patients despite an apparently "radical" surgery. Metastatic dissemination might be favored by a poor adherence to chemotherapy. Combined surgery and continuous administration of albendazole at high dosage may allow alveolar echinococcosis patients to survive more than 30 years after diagnosis despite multi-organ involvement.

Liver transplantation for unresectable hepatocellular carcinoma in normal livers.

BACKGROUND & AIMS: The role of liver transplantation in the treatment of hepatocellular carcinoma in livers without fibrosis/cirrhosis (NC-HCC) is unclear. We aimed to determine selection criteria for liver transplantation in patients with NC-HCC. METHODS: Using the European Liver Transplant Registry, we identified 105 patients who underwent liver transplantation for unresectable NC-HCC. Detailed information about patient, tumor characteristics, and survival was obtained from the transplant centers. Variables associated with survival were identified using univariate and multivariate statistical analyses. RESULTS: Liver transplantation was primary treatment in 62 patients and rescue therapy for intrahepatic recurrences after liver resection in 43. Median number of tumors was 3 (range 1-7) and median tumor size 8 cm (range 0.5-30). One- and 5-year overall and tumor-free survival rates were 84% and 49% and 76% and 43%, respectively. Macrovascular invasion (HR 2.55, 95% CI 1.34 to 4.86), lymph node involvement (HR 2.60, 95% CI 1.28 to 5.28), and time interval between liver resection and transplantation < 12 months (HR 2.12, 95% CI 0.96 to 4.67) were independently associated with survival. Five-year survival in patients without macrovascular invasion or lymph node involvement was 59% (95% CI 47-70%). Tumor size was not associated with survival. CONCLUSIONS: This is the largest reported series of patients transplanted for NC-HCC. Selection of patients without macrovascular invasion or lymph node involvement, or patients ≥ 12months after previous liver resection, can result in 5-year survival rates of 59%. In contrast to HCC in cirrhosis, tumor size is not a predictor of post-transplant survival in NC-HCC.

Hepatocyte proliferation/growth arrest balance in the liver of mice during E. multilocularis infection: a coordinated 3-stage course.

BACKGROUND: Alveolar echinococcosis (AE) is characterized by the tumor-like growth of Echinococcus (E.) multilocularis. Very little is known on the influence of helminth parasites which develop in the liver on the proliferation/growth arrest metabolic pathways in the hepatocytes of the infected liver over the various stages of infection. METHODOLOGY/PRINCIPAL FINDINGS: Using Western blot analysis, qPCR and immunohistochemistry, we measured the levels of MAPKs activation, Cyclins, PCNA, Gadd45ß, Gadd45γ, p53 and p21 expression in the murine AE model, from day 2 to 360 post-infection. Within the early (day 2-60) and middle (day60-180) stages, CyclinB1 and CyclinD1 gene expression increased up to day30 and then returned to control level after day60; Gadd45ß, CyclinA and PCNA increased all over the period; ERK1/2 was permanently activated. Meanwhile, p53, p21 and Gadd45γ gene expression, and caspase 3 activation, gradually increased in a time-dependent manner. In the late stage (day180-360), p53, p21 and Gadd45γ gene expression were significantly higher in infected mice; JNK and caspase 3 were activated. TUNEL analysis showed apoptosis of hepatocytes. No significant change in CyclinE, p53 mRNA and p-p38 expression were observed at any time. CONCLUSIONS: Our data support the concept of a sequential activation of metabolic pathways which 1) would first favor parasitic, liver and immune cell proliferation and survival, and thus promote metacestode fertility and tolerance by the host, and 2) would then favor liver damage/apoptosis, impairment in protein synthesis and xenobiotic metabolism, as well as promote immune deficiency, and thus contribute to the dissemination of the protoscoleces after metacestode fertility has been acquired. These findings give a rational explanation to the clinical observations of hepatomegaly and of unexpected survival of AE patients after major hepatic resections, and of chronic liver injury, necrosis and of hepatic failure at an advanced stage and in experimental animals.

Should possible recurrence of disease contraindicate liver transplantation in patients with end-stage alveolar echinococcosis? A 20-year follow-up study.

Liver transplantation (LT) is currently contraindicated in patients with residual or metastatic alveolar echinococcosis (AE) lesions. We evaluated the long-term course of such patients who underwent LT and were subsequently treated with benzimidazoles. Clinical, imaging, serological, and therapeutic data were collected from 5 patients with residual/recurrent AE lesions who survived for more than 15 years. Since 2004, [(18) F]-2-fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) images were available, and the levels of serum antibodies (Abs) against Echinococcus multilocularis-recombinant antigens were evaluated. Median survival time after LT was 21 years. These patients were from a prospective cohort of 23 patients with AE who underwent LT: 5 of 8 patients with residual/recurrent AE and 4 of 9 patients without residual/recurrent AE were alive in September 2009. High doses of immunosuppressive drugs, the late introduction of therapy with benzimidazoles, its withdrawal due to side effects, and nonadherence to this therapy adversely affected the prognosis. Anti-Em2(plus) and anti-rEm18 Ab levels and standard FDG-PET enabled the efficacy of therapy on the growth of EA lesions to be assessed. However, meaningful variations in Ab levels were observed below diagnostic cutoff values; and in monitoring AE lesions, images of FDG uptake taken 3 hours after its injection were more sensitive than images obtained 1 hour after its injection. In conclusion, benzimidazoles can control residual/recurrent AE lesions after LT. Using anti-rEm18 or anti-Em2(plus) Ab levels and the delayed acquisition of FDG-PET images can improve the functional assessment of disease activity. The potential recurrence of disease, especially in patients with residual or metastatic AE lesions, should not be regarded as a contraindication to LT when AE is considered to be lethal in the short term.

Clinical features and evolution of alveolar echinococcosis in France from 1982 to 2007: results of a survey in 387 patients.

BACKGROUND & AIMS: Alveolar echinococcosis (AE) is a rare disease in humans, caused by the larval stage of the fox tapeworm Echinococcus multilocularis. METHODS: We present here 387 detailed AE cases diagnosed in France from 1982 to 2007 actively identified by a retrospective survey performed in 1997-1998 and prospectively thereafter. RESULTS: Male:female ratio was 1.03 and mean age 57.8 years at time of diagnosis. Among the 362 complete files (including 347 non dead-out and 15 dead-out lesions), 73% of the patients were symptomatic at first admittance. Among them, 83% presented with clinical patterns evocative either of a digestive or a hepatic disorder. Other symptomatic patients presented with erratic clinical pictures, generally due to metastasis or extra-hepatic location of the parasite. Except for a few patients with particularly severe AE who died shortly after the diagnosis, most patients were treated using benzimidazoles. Their mortality tends to merge with that of the general French population, matched by sex, age, and calendar year. This study also highlights an unexpectedly high frequency of blood-tied family cases (13% of patients submitted to a specific questionnaire). CONCLUSIONS: Even though the broad set of clinical features provoked by E. multilocularis makes AE a potential diagnostic trap for many physicians, our study revealed an improvement of its prognosis. However, as shown by our findings about the frequency of family cases, there is still a need for studies aimed at better describing this uncommon parasitic disease.

Time course of gene expression profiling in the liver of experimental mice infected with Echinococcus multilocularis.

BACKGROUND: Alveolar echinococcosis (AE) is a severe chronic parasitic disease which behaves like a slow-growing liver cancer. Clinical observations suggest that the parasite, Echinococcus multilocularis (E. multilocularis) influences liver homeostasis and hepatic cell metabolism. However, this has never been analyzed during the time course of infection in the common model of secondary echinococcosis in experimental mice. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression profiles were assessed using DNA microarray analysis, 1, 2, 3 and 6 months after injection of E. multilocularis metacestode in the liver of susceptible mice. Data were collected at different time points to monitor the dynamic behavior of gene expression. 557 differentially expressed genes were identified at one or more time points, including 351 up-regulated and 228 down-regulated genes. Time-course analysis indicated, at the initial stage of E. multilocularis infection (month 1-2), that most of up-regulated pathways were related to immune processes and cell trafficking such as chemokine-, mitogen-activated protein kinase (MAPK) signaling, and down-regulated pathways were related to xenobiotic metabolism; at the middle stage (month 3), MAPK signaling pathway was maintained and peroxisome proliferator-activated receptor (PPAR) signaling pathway emerged; at the late stage (month 6), most of up-regulated pathways were related to PPAR signaling pathway, complement and coagulation cascades, while down-regulated pathways were related to metabolism of xenobiotics by cytochrome P450. Quantitative RT-PCR analysis of a random selection of 19 genes confirmed the reliability of the microarray data. Immunohistochemistry analysis showed that proliferating cell nuclear antigen (PCNA) was increased in the liver of E. multilocularis infected mice from 2 months to 6 months. CONCLUSIONS: E. multilocularis metacestode definitely exerts a deep influence on liver homeostasis, by modifying a number of gene expression and metabolic pathways. It especially promotes hepatic cell proliferation, as evidenced by the increased PCNA constantly found in all the experimental time-points we studied and by an increased gene expression of key metabolic pathways.