Genetic algorithms identify individuals with high risk of severe liver disease caused by schistosomes.

Schistosomes induce severe hepatic disease, which is fatal in 2-10% of cases, mortality being higher in cases of co-infection with HBV or HCV. Hepatic disease occurs as a consequence of the chronic inflammation caused by schistosome eggs trapped in liver sinusoids. In certain individuals, the repair process leads to a massive accumulation of fibrosis in the periportal spaces. We and others have shown that genetic variants play a crucial role in disease progression from mild to severe fibrosis and explain why hepatic fibrosis progresses rapidly in certain subjects only. We will review here published findings concerning the strategies that have been used in the analysis of hepatic fibrosis in schistosome-infected individuals, the genetic variants that have associated with fibrosis, and variants in new pathways crucial for fibrosis progression. Together, these studies show that the development of fibrosis is under the tight genetic control of various common variants with moderate effects. This polygenic control has made it possible to develop models that identify schistosome-infected individual at risk of severe hepatic disease. We discuss the performances and limitations of these models.

Recombinant adeno-associated virus-mediated inhibition of microRNA-21 protects mice against the lethal schistosome infection by repressing both IL-13 and transforming growth factor beta 1 pathways.

UNLABELLED: Schistosomiasis is a serious parasitic disease in humans, which can lead to liver fibrosis and death. Accumulating evidence indicated that targeting the deregulated microRNAs (miRNAs) could mitigate disease outcomes. Here, we showed that progressive hepatic schistosomiasis caused elevation of miR-21 and efficient and sustained inhibition of miR-21 by using highly hepatic tropic adeno-associated virus serotype 8 (rAAV8), which protected mice against lethal schistosome infection through attenuation of hepatic fibrosis (HF). We demonstrated an additive role of interleukin (IL)-13 and transforming growth factor beta 1 (TGF-ß1) in up-regulating miR-21 expression in hepatic stellate cells (HSCs) by activation of mothers against decapentaplegic (SMAD) proteins. Furthermore, down-regulation of miR-21 in HSCs reversed HF by enhancing SMAD7 expression, thus repressing TGF-ß1/Smad and IL-13/Smad pathways. CONCLUSION: This study suggests the mechanism of IL-13-mediated schistosomiasis HF by up-regulation of miR-21 and highlights the potential of rAAV8-mediated miR-21 inhibition as a therapeutic intervention for hepatic fibrotic diseases, such as schistosomiasis.

Genetic analysis of human predisposition to hepatosplenic disease caused by schistosomes reveals the crucial role of connective tissue growth factor in rapid progression to severe hepatic fibrosis.

Schistosome worms inhabit mammalian mesenteric veins. Their eggs cause chronic inflammation, which progresses to periportal fibrosis in 5 to 30% of cases, increasing portal blood pressure and leading to esophageal varices. Episodes of bleeding cause hepatic necrosis and may ultimately lead to hepatic failure and the death of the patient. Schistosome infections can also cause pulmonary hypertension and heart failure. The mechanisms of fibrogenesis and fibrolysis are beginning to be unraveled, but it remains unclear why disease occurs only in certain subjects, as also observed for other types of chronic liver inflammation, as in hepatitis C or B. We summarize here the results that showed that fibrosis progression is determined by a genetic locus on chromosome 6. The CCN2 gene at this locus, encodes CTGF that is a crucial regulator of fibrosis. Two groups of CCN2 polymorphisms independently modulate the progression of hepatic fibrosis. These results were obtained in an Asian population, but were extended to humans living in Africa and South America and are presently tested in liver fibrosis of other etiological origins.

Bioengineered Liver Cell Models of Hepatotropic Infections.

Hepatitis viruses and liver-stage malaria are within the liver infections causing higher morbidity and mortality rates worldwide. The highly restricted tropism of the major human hepatotropic pathogens-namely, the human hepatitis B and C viruses and the Plasmodium falciparum and Plasmodium vivax parasites-has hampered the development of disease models. These models are crucial for uncovering the molecular mechanisms underlying the biology of infection and governing host-pathogen interaction, as well as for fostering drug development. Bioengineered cell models better recapitulate the human liver microenvironment and extend hepatocyte viability and phenotype in vitro, when compared with conventional two-dimensional cell models. In this article, we review the bioengineering tools employed in the development of hepatic cell models for studying infection, with an emphasis on 3D cell culture strategies, and discuss how those tools contributed to the level of recapitulation attained in the different model layouts. Examples of host-pathogen interactions uncovered by engineered liver models and their usefulness in drug development are also presented. Finally, we address the current bottlenecks, trends, and prospect toward cell models' reliability, robustness, and reproducibility.

Imaging techniques and histology in the evaluation of liver fibrosis in hepatosplenic schistosomiasis mansoni in Brazil: a comparative study.

Few publications have compared ultrasound (US) to histology in diagnosing schistosomiasis-induced liver fibrosis (LF); none has used magnetic resonance (MR). The aim of this study was to evaluate schistosomal LF using these three methods. Fourteen patients with hepatosplenic schistosomiasis admitted to hospital for surgical treatment of variceal bleeding were investigated. They were submitted to upper digestive endoscopy, US, MR and wedge liver biopsy. The World Health Organization protocol for US in schistosomiasis was used. Hepatic fibrosis was classified as absent, slight, moderate or intense. Histology and MR confirmed Symmers' fibrosis in all cases. US failed to detect it in one patient. Moderate agreement was found comparing US to MR; poor agreement was found when US or MR were compared to histology. Re-classifying LF as only slight or intense created moderate agreement between imaging techniques and histology. Histomorphometry did not separate slight from intense LF. Two patients with advanced hepatosplenic schistosomiasis presented slight LF. Our data suggest that the presence of the characteristic periportal fibrosis, diagnosed by US, MR or histology, associated with a sign of portal hypertension, defines the severity of the disease. We conclude that imaging techniques are reliable to define the presence of LF but fail in grading its intensity.

[Clinical characteristics and distribution of peripheral T lymphocyte subsets in patients with schistosomal hepatic diseases in Suzhou City].

OBJECTIVE: To investigate the clinical characteristics and the distribution of peripheral blood T lymphocyte sub-sets in patients with schistosomal hepatic cirrhosis in Suzhou City. METHODS: A total of 32 inpatients with liver diseases due to advanced schistosomiasis at the Department of Infectious Diseases, The First Affiliated Hospital of Soochow University from January 2016 to January 2018 were recruited and assigned into the infection and non-infection groups according to presence of co-infections, and 20 old healthy volunteers served as controls. Venous blood samples were collected on the day of admission, and the proportions of CD4+ T cells, CD8+ T cells, regulatory T (Treg) cells and Th17 cells were detected in peripheral blood using flow cytometry. RESULTS: Most patients with liver disorders due to advanced schistosomiasis were admitted to hospital in Suzhou City because of portal hypertension-associated complications, with a high prevalence of co-infections (59.38%, 19/32). The proportions of peripheral CD4+ and CD8+ T cells and Th17 cells were all significantly lower in patients with liver disorders due to advanced schistosomiasis than in controls (t = -5.111, -4.470 and -2.749, all P < 0.05), and a higher proportion of Treg cells was detected in patients than in controls (t = 5.628, P < 0.05). In addition, there were significant differences among the infection group, non-infection group and controls in terms of the percentage of CD4+ T cells, CD8+ T cells, Th17 cells and Treg cells (F = 15.837, 16.594, 9.290 and 27.866, all P < 0.05). CONCLUSIONS: Portal hypertension-associated complications are predominantly seen in patients with liver diseases due to advanced schistosomiasis at admission in Suzhou City, and co-infections are common. Imbalance of peripheral T cell subsets is detected in patients with liver diseases due to advanced schistosomiasis in Suzhou City.

Opisthorchis viverrini Proteome and Host-Parasite Interactions.

The omics technologies have improved our understanding of the molecular events that underpin host-parasite interactions and the pathogenesis of parasitic diseases. In the last decade, proteomics and genomics in particular have been used to characterize the surface and secreted products of the carcinogenic liver fluke Opisthorchis viverrini and revealed important roles for proteins at the host-parasite interface to ensure that the flukes can migrate, feed and reproduce in a hostile environment. This review summarizes the advances made in this area, primarily focusing on discoveries enabled by the publication of the fluke secreted proteomes over the last decade. Protein families that will be covered include proteases, antioxidants, oncogenic proteins and the secretion of exosome-like extracellular vesicles. Roles of these proteins in host-parasite interactions and pathogenesis of fluke-induced hepatobiliary diseases, including cholangiocarcinogenesis, are discussed. Future directions for the application of this knowledge to control infection and disease will also be discussed.

[Liver injury in visceral leishmaniasis in children: systematic review]. / Alteraciones hepáticas en la Leishmaniasis Visceral (Kalazar) en niños: revisión sistemática de la literatura.

UNLABELLED: Visceral Leisshimaniosis or Kalazar is a parasitic infection caused by Leishimania Donovani subspecies. It is transmitted by phlebotomineos and may lead to liver and spleen enlargements as well as immunological impairment. Sometimes it is described liver injury simulating acute or chronic viral hepatitis and even portal hypertension. The liver injury makes difficult the diffencial diagnosis of Kalazar and other liver diseases in endemic regions. OBJECTIVE: To define and clarify the liver injury spectrum described in published cases reports. METHODS: Systematic revision of published data on Kalazar and liver injury using the following databank: LILACS, MEDLINE and EMBASE. Only paper published in French, English, Portuguese and Spanish were taken into consideration. The procedures for systematic review recommended by the NHS Centre for Reviews and Dissemination, University of Cork, were adopted. The paper quality classification was based on the number of reported variables previously defined in our study RESULTS: Only 11/28 (55%) publications were included in our analysis because they filled the minimal required data. Acute and chronic liver disease were well documented in these articles. Serum albumin and prothombine time were associated with severity of liver disease (P < .05). CONCLUSION: "Liver involvement, even when it is severe, may occur at tha begining of the disease. Kalazar should be considered as a differential diagnosis of cholestasis, acute and chronic liver injury as well as portal hypertension in children.

[Re-understanding of liver cirrhosis induced by Schistosomiasis japonica].

Whether the hepatic pipestem fibrosis induced by schistosomiasis japonica can result in cirrhosis, confusion exists among parasitologists in China. Evidence from national and international pathologists and clinicians confirmed that the pipestem fibrosis could develop into cirrhosis undoubtedly. Owing to different pathogenic causes, the characters of cirrhosis are different. To re-understand cirrhosis induced by Schistosomiasis japonica is of significance for the diagnosis and treatment of the advanced patient.

Cx3cr1 deficiency in mice attenuates hepatic granuloma formation during acute schistosomiasis by enhancing the M2-type polarization of macrophages.

Acute schistosomiasis is characterized by pro-inflammatory responses against tissue- or organ-trapped parasite eggs along with granuloma formation. Here, we describe studies in Cx3cr1(-/-) mice and demonstrate the role of Cx3cr1 in the pathoetiology of granuloma formation during acute schistosomiasis. Mice deficient in Cx3cr1 were protected from granuloma formation and hepatic injury induced by Schistosoma japonicum eggs, as manifested by reduced body weight loss and attenuated hepatomegaly along with preserved liver function. Notably, S. japonicum infection induced high levels of hepatic Cx3cr1 expression, which was predominantly expressed by infiltrating macrophages. Loss of Cx3cr1 rendered macrophages preferentially towards M2 polarization, which then led to a characteristic switch of the host immune defense from a conventional Th1 to a typical Th2 response during acute schistosomiasis. This immune switch caused by Cx3cr1 deficiency was probably associated with enhanced STAT6/PPAR-γ signaling and increased expression of indoleamine 2,3-dioxygenase (IDO), an enzyme that promotes M2 polarization of macrophages. Taken together, our data provide evidence suggesting that CX3CR1 could be a viable therapeutic target for treatment of acute schistosomiasis.

Humoral immune responses in human hepatosplenic schistosomiasis mansoni.

The development of hepatosplenic schistosomiasis in humans cannot always be related to the intensity of infection. A study was designed to identify different humoral immunologic responses to Schistosoma mansoni in patients with and without hepatosplenic disease. Twenty-four patients with active hepatosplenic disease were closely matched for age, sex, and fecal egg counts with twenty-four patients with only intestinal disease. A serum sample from each of these patients was tested for antibodies to the major soluble egg antigen (MSA1) by radioimmunoassay, for total and IgM antibodies to egg and worm antigenic preparations by ELISA, and for its ability to suppress antigen stimulated lymphocyte blastogenesis. No difference was found using these assays between the hepatosplenic and the intestinal schistosomiasis patients.

Lack of association of hepatosplenic schistosomiasis and alpha-1-antitrypsin deficiency.

To evaluate the role of alpha-1-antitrypsin deficiency in the pathogenesis of hepatosplenic schistosomiasis, alpha-1-antitrypsin was measured in 90 patients with schistosomal splenomegaly and in 87 phenotyping was also done. All levels were in the normal range except for those of two patients who were shown to have the heterozygous deficiency state, PiMZ. The phenotypes found in the 87 were as would be expected in a normal population. Alpha-1-antitrypsin deficiency does not play a significant role in the pathogenesis of hepatosplenic schistosomiasis.

Demonstration of hypnozoites in sporozoite-transmitted Plasmodium vivax infection.

Hypnozoites of two strains of the human relapsing malaria parasite, Plasmodium vivax, have been detected among maturing 7- and 10-day pre-erythrocytic schizonts in liver biopsies of chimpanzees infected by intravenous inoculation of sporozoites obtained from dissected salivary glands of heavily infected anopheline mosquitoes. As in the simian relapsing species, P. cynomolgi, the hypnozoites of P. vivax at 7 and 10 days are uninucleate forms of approximately 4-5 micrometers diameter, lying within the cytoplasm of individual hepatocytes. Their presence in this relapsing human species is added support for the hypnozoite theory of malarial relapse.

Immunity and immunopathology following reinfection of mice cured of chronic schistosomiasis mansoni.

The effect of curative treatment of murine schistosomiasis mansoni on resistance to reinfection and on granulomatous hypersensitivity following reinfection was studied. The sera of mice with light chronic Schistosoma mansoni infection of 32 weeks duration were tested by immunodiffusion analysis with soluble egg antigens for a precipitin band containing an antigen specific for eggs in order to identify bisexual infections. A group of the 32 week bisexually-infected mice were treated with niridazole, as was a similar group of uninfected mice. Six weeks later (at 38 weeks) the previously infected mice were injected subcutaneously with 30 cercariae and the uninfected mice with 20 cercariae. On perfusion 12 weeks later the secondarily infected mice had a percentage worm yield following infection of 16 while that in the primarily infected mice was 60. Twelve weeks after reinfection (at 50 weeks), the previously infected mice had moderate hepatosplenic disease similar to the mice which had remained constantly infected for 50 weeks, and formed relatively small granulomas around eggs injected into their pulmonary microvasculature. In spite of much lower liver egg counts, particularly severe hepatosplenic disease was seen in the previously uninfected mice. When eggs were injected into their lungs, however, very large granulomas were observed. These experiments suggest that both immunity and modulation of immunopathology are residual after curative treatment.

Altered schistosome granuloma formation in nude mice.

Schistosome egg-induced lesions in congenitally athymic mice differed from those found in normal heterozygous controls. Heterozygote liver granulomas were chareacterized by poorly phagocytic epithelioid macrophages, and were rich in eosinophils and fibroblasts, with peripheral lymphocytes and plasma cells. Hepatic lesions in nude mice were much smaller and lacked epithelioid macrophages, with lesions about mature eggs, typically consisting of monocytes and macrophages filled with pigment, occasional neutrophils, and rarely one or more eosinophils or giant cells. While heterozygote granulomas damaged liver cells mainly by encroachment or by their vascular effects, in the nudes hepatocytes bordering the lesions showed microvesicular cytoplasmic damage and either hydropic degeneration or focal acidophilic necrosis of individual liver cells. In heterozygotes, immunofluorescent-stainable schistosome egg antigen (SEA) was concentrated in the granuloma center. In nude mice, SEA, was distributed throughout the infiltrates and in and around hepatocytes adjacent to egg lesions corresponding to the observed pattern of hepatocyte necrosis. We conclude that, in contrast to heterozygotes, nude mice lack hypersensitivity granulomas and fail to sequester toxic egg products, this resulting in zonal hepatocellular damage. Alternative explanations include the possibility of a latent hepatitis virus being activated by the schistosome infection; however, several cogent arguments are presented against that alternative.

Renal involvement in patients with hepatosplenic Schistosomiasis mansoni.

In a prospective study of renal involvement in 100 consecutively hospitalized patients with hepatosplenic schistosomiasis mansoni, 15 exhibited persistent proteinuria of varying degree, which in 6 instances was accompanied by hypertension. Nine patients had the nephrotic syndrome. The most common glomerular lesion in this group was membrano-proliferative glomerulonephritis. Surgical biospy obtained during splenectomy in 15 patients without clinical evidence of renal involvement showed glomerular lesions in 6 instances. Focal proliferative glomerulonephritis was the most common lesion in this group. The detection of silent glomerular lesions in patients with Schistosoma mansoni infection suggests that the glomerular alterations may precede clinical manifestations of renal disease.

Severe and complicated falciparum malaria in Melanesian adults in Papua New Guinea.

Severe falciparum malaria usually occurs in children, but also occurs in nonimmune migrants or partially immune adults in areas of unstable transmission. We have studied prospectively 70 adult patients with strictly defined severe malaria from the south coast of Papua New Guinea where malaria transmission is not intense. Only 19 (27.1%) were migrants from areas where malaria transmission does not occur; many other patients were periurban dwellers who had become infected after visits to their home villages. The most common clinical features were jaundice or hepatic dysfunction, impaired consciousness, renal failure, cerebral malaria, and anemia. Hypoglycemia was common following treatment with quinine. The overall case fatality rate was 18.6%; renal failure and cerebral malaria in particular were associated with a poor outcome. Reduction in mortality might be achieved by aggressive therapy of renal failure with earlier institution of dialysis; the use of preventive measures for immigrants or urban dwellers returning to high transmission areas might reduce the incidence of this dangerous disease.

Subcutaneous implantation of the spleen as a new technique for experimental induction of hepatic Schistosoma mansoni egg granulomas.

Schistosoma mansoni egg granulomas were induced in the livers of mice by injecting eggs into spleens which had been surgically exposed with their vascular beds intact. Subsequent return of the spleens to a subcutaneous site allows repeated injections of eggs into the liver if necessary.

Hepatopathy in complicated falciparum malaria: report from eastern India.

A prospective study done in 216 children with complicated falciparum malaria showed hepatopathy in 33.3% of cases with a higher incidence in children aged above five years. Bilirubin and alanine aminotransferase were moderately raised in most cases. No significant association with other common complications and no higher risk of mortality was observed.