Massive pleural empyema secondary to amoebic liver abscess in a child.

BACKGROUND: Pleural empyema secondary to a ruptured amoebic liver abscess is a rare complication in the pediatric population. CASE REPORT: We report the case of a 13-year-old male with right flank abdominal pain, productive cough with foul-smelling sputum, fever, and respiratory distress. Physical examination revealed breathlessness, decreased vesicular murmur in the right hemithorax, abdominal distension, hepatomegaly, and lower limb edema. Laboratory tests revealed mild anemia, leukocytosis without eosinophilia, elevated alkaline phosphatase, hypoalbuminemia, and positive immunoglobulin G antibodies against Entamoeba histolytica in pleural fluid. He required a chest tube and treatment with metronidazole. After 2 months of follow-up, the abscesses disappeared, and the empyema decreased. CONCLUSIONS: Massive pleural empyema secondary to a ruptured liver abscess is a rare complication. The epidemiological link associated with the symptoms and serological tests can help in the diagnosis.

INTRODUCCIÓN: El empiema pleural secundario a ruptura de absceso amebiano hepático es una complicación poco frecuente en la población pediátrica. CASO CLÍNICO: Se reporta el caso de un paciente de sexo masculino de 13 años que presentó dolor abdominal en flanco derecho, tos productiva con esputo de mal olor, fiebre y dificultad respiratoria. Al examen físico se encontró amplexación y murmullo vesicular disminuido en hemitórax derecho, distensión abdominal, hepatomegalia y edema de miembros inferiores. Los resultados del laboratorio evidenciaron anemia leve, leucocitosis sin eosinofilia, elevación de fosfatasa alcalina, hipoalbuminemia y anticuerpos IgG contra Entamoeba histolytica positivo en líquido pleural. Requirió tubo de drenaje torácico y tratamiento con metronidazol. A los dos meses de seguimiento los abscesos desaparecieron y el empiema disminuyó. CONCLUSIONES: El empiema pleural masivo secundario a ruptura de absceso hepático es una complicación poco frecuente. El nexo epidemiológico asociado con la sintomatología y pruebas serológicas pueden ser de ayuda en el diagnóstico.

Apocynin, an NADPH Oxidase Enzyme Inhibitor, Prevents Amebic Liver Abscess in Hamster.

Amebiasis is an intestinal infection caused by Entamoeba histolytica. Amebic liver abscess (ALA) is the most common extraintestinal complication of amebiasis. In animal models of ALA, neutrophils have been shown to be the first cells to come into contact with Entamoeba histolytica during the initial phase of ALA. One of the multiple mechanisms by which neutrophils exhibit amebicidal activity is through reactive oxygen species (ROS) and the enzyme NADPH oxidase (NOX2), which generates and transports electrons to subsequently reduce molecular oxygen into superoxide anion. Previous reports have shown that ROS release in the susceptible animal species (hamster) is mainly stimulated by the pathogen, in turn provoking such an exacerbated inflammatory reaction that it is unable to be controlled and results in the death of the animal model. Apocynin is a natural inhibitor of NADPH oxidase. No information is available on the role of NOX in the evolution of ALA in the hamster, a susceptible model. Our study showed that administration of a selective NADPH oxidase 2 (NOX2) enzyme inhibitor significantly decreases the percentage of ALA, the size of inflammatory foci, the number of neutrophils, and NOX activity indicated by the reduction in superoxide anion (O2-) production. Moreover, in vitro, the apocynin damages amoebae. Our results showed that apocynin administration induces a decrease in the activity of NOX that could favor a decrease in ALA progression.

Massive pleural empyema secondary to amoebic liver abscess in a child / Empiema pleural masivo secundario a absceso hepático amebiano en un niño

Abstract Background: Pleural empyema secondary to a ruptured amoebic liver abscess is a rare complication in the pediatric population. Case report: We report the case of a 13-year-old male with right flank abdominal pain, productive cough with foul-smelling sputum, fever, and respiratory distress. Physical examination revealed breathlessness, decreased vesicular murmur in the right hemithorax, abdominal distension, hepatomegaly, and lower limb edema. Laboratory tests revealed mild anemia, leukocytosis without eosinophilia, elevated alkaline phosphatase, hypoalbuminemia, and positive immunoglobulin G antibodies against Entamoeba histolytica in pleural fluid. He required a chest tube and treatment with metronidazole. After 2 months of follow-up, the abscesses disappeared, and the empyema decreased. Conclusions: Massive pleural empyema secondary to a ruptured liver abscess is a rare complication. The epidemiological link associated with the symptoms and serological tests can help in the diagnosis.

Resumen Introducción: El empiema pleural secundario a ruptura de absceso amebiano hepático es una complicación poco frecuente en la población pediátrica. Caso clínico: Se reporta el caso de un paciente de sexo masculino de 13 años que presentó dolor abdominal en flanco derecho, tos productiva con esputo de mal olor, fiebre y dificultad respiratoria. Al examen físico se encontró amplexación y murmullo vesicular disminuido en hemitórax derecho, distensión abdominal, hepatomegalia y edema de miembros inferiores. Los resultados del laboratorio evidenciaron anemia leve, leucocitosis sin eosinofilia, elevación de fosfatasa alcalina, hipoalbuminemia y anticuerpos IgG contra Entamoeba histolytica positivo en líquido pleural. Requirió tubo de drenaje torácico y tratamiento con metronidazol. A los dos meses de seguimiento los abscesos desaparecieron y el empiema disminuyó. Conclusiones: El empiema pleural masivo secundario a ruptura de absceso hepático es una complicación poco frecuente. El nexo epidemiológico asociado con la sintomatología y pruebas serológicas pueden ser de ayuda en el diagnóstico.

Differential Pathogenic Gene Expression of E. histolytica in Patients with Different Clinical Forms of Amoebiasis.

The etiological agent of human amoebiasis is the protozoan parasite E. histolytica; the disease is still an endemic infection in some countries and the outcome of infection in the host infection can range from asymptomatic intestinal infection to intestinal or liver invasive forms of the disease. The invasive character of this parasite is multifactorial and mainly due to the differential expression of multiple pathogenic genes. The aim of the present work was to measure the differential expression of some genes in different specimens of patients with amoebic liver abscess (ALA) and specimens of genital amoebiasis (AG) by RT-qPCR. Results show that the expression of genes is different in both types of samples. Almost all studied genes were over expressed in both sets of patients; however, superoxide dismutase (Ehsod), serine threonine isoleucine rich protein (Ehstirp), peroxiredoxin (Ehprd) and heat shock protein 70 and 90 (Ehhsp-70, EHhsp-90) were higher in AG biopsies tissue. Furthermore, cysteine proteinases 5 and 2 (Ehcp5, Ehcp2), lectin (Ehgal/galnaclectin) and calreticulin (Ehcrt) genes directly associate with pathogenic mechanisms of E. histolytica had similar over expression in both AG and ALA samples. In summary the results obtained show that trophozoites can regulate the expression of their genes depending on stimuli or environmental conditions, in order to regulate their pathogenicity and ensure their survival in the host.

Entamoeba histolytica Interaction with Enteropathogenic Escherichia coli Increases Parasite Virulence and Inflammation in Amebiasis.

Epidemiological studies suggest frequent association of enteropathogenic bacteria with Entamoeba histolytica during symptomatic infection. In this study, we sought to determine if the interaction with enteropathogenic (EPEC) or nonpathogenic Escherichia coli (strain DH5α) could modify the virulence of E. histolytica to cause disease in animal models of amebiasis. In vitro studies showed a 2-fold increase in CaCo2 monolayer destruction when E. histolytica interacted with EPEC but not with E. coli DH5α for 2.5 h. This was associated with increased E. histolytica proteolytic activity as revealed by zymogram analysis and degradation of the E. histolytica CP-A1/5 (EhCP-A1/5) peptide substrate Z-Arg-Arg-pNC and EhCP4 substrate Z-Val-Val-Arg-AMC. Additionally, E. histolytica-EPEC interaction increased EhCP-A1, -A2, -A4, and -A5, Hgl, Apa, and Cox-1 mRNA expression. Despite the marked upregulation of E. histolytica virulence factors, nonsignificant macroscopic differences in amebic liver abscess development were observed at early stages in hamsters inoculated with either E. histolytica-EPEC or E. histolytica-E. coli DH5α. Histopathology of livers of E. histolytica-EPEC-inoculated animals revealed foci of acute inflammation 3 h postinoculation that progressively increased, producing large inflammatory reactions, ischemia, and necrosis with high expression of il-1ß, ifn-γ, and tnf-α proinflammatory cytokine genes compared with that in livers of E. histolytica-E. coli DH5α-inoculated animals. In closed colonic loops from mice, intense inflammation was observed with E. histolytica-EPEC manifested by downregulation of Math1 mRNA with a corresponding increase in the expression of Muc2 mucin and proinflammatory cytokine genes il-6, il-12, and mcp-1 These results demonstrate that E. histolytica/EPEC interaction enhanced the expression and production of key molecules associated with E. histolytica virulence, critical in pathogenesis and progression of disease.

Biliary Peritonitis due to a Ruptured Amebic Liver Abscess Mimicking a Periampullary Tumor and Liver Metastases with the Elevation of CA 19-9 and CA 125: A Case Report.

INTRODUCTION: An amebic liver abscess is the most common presentation of extraintestinal amebiasis. This condition is the result of a parasite infection caused by Entamoeba histolytica. MATERIALS AND METHODS: We report a case of a 53-year-old male who presented with abdominal pain in the right upper quadrant, jaundice, and a 10-kg weight loss within a 1-month span. RESULTS AND CONCLUSION: A wide range of symptoms and findings in the imaging tests suggestive of neoplasia, elevated levels of CA 19-9 and CA 125, and the presentation of biliary peritonitis as a complication makes this case a challenge for its approach and management.

INTRODUÇÃO: O abcesso amebiano é a apresentação mais comum da amebíase extraintestinal. Esta condição é resultado da infeção pelo parasita Entamoeba histolytica. MATERIAIS E MÉTODOS: Reportamos um caso clínico de um homem de 53 anos com dor abdominal no quadrante superior direito, icterícia e emagrecimento de 10 kg em 1 mês. RESULTADOS E CONCLUSÕES: Os sintomas e os achados imagiológicos sugestivos de neoplasia, os níveis elevados de CA 19-9 e CA 125 e a apresentação como peritonite biliar tornam este caso um desafio de diagnóstico e abordagem clínica.

Entamoeba histolytica Calreticulin Induces the Expression of Cytokines in Peripheral Blood Mononuclear Cells Isolated From Patients With Amebic Liver Abscess.

Calreticulin (CRT) is a highly conserved protein in the endoplasmic reticulum that plays important roles in the regulation of key cellular functions. Little is known about the participation of E. histolytica CRT (EhCRT) in the processes of pathogenicity or in the modulation of the host immune response. The aim of this study was to evaluate the role of CRT in the proliferation and the cytokine profile in peripheral blood mononuclear cells (PBMCs) from patients with amebic liver abscess (ALA) during the acute phase (AP-ALA) of the disease compared to patients during the resolution phase (R-ALA). The PBMCs from each participant were cocultured with EhCRT and tested by the colorimetric method to evaluate their proliferation index (PI). The supernatants were subjected to an enzyme-linked immunosorbent assay (ELISA) to evaluate the concentration of cytokines. The mean values of all groups were compared using the independent t-test. When the PIs of individuals without diagnosis of liver abscess (NEG) were compared, there were no statistically significant differences in the proliferation of PBMCs between patients with AP-ALA and R-ALA when stimulated with EhCRT or concanavalin A (ConA). However, the levels of interleukins [IL-6, IL-10, granulocyte colony stimulating factor (GCSF), and transforming growth factor ß1 (TGFß1)] were higher in patients with AP-ALA, whereas in patients with R-ALA, higher levels of interferon gamma (IFNγ) were detected. These results suggest that EhCRT acts as a mitogen very similar to the activity of ConA. In addition, EhCRT is an excellent immunogen for the specific activation of PBMCs, inducing the differential expression of ILs depending on the outcome of disease, determining the type of immune response: a Th2 cytokine profile during the acute phase and a Th1 profile during the resolution phase.

Characterization of the protein tyrosine phosphatase PRL from Entamoeba histolytica.

Protein tyrosine phosphatase of regenerating liver (PRL) is a group of phosphatases that has not been broadly studied in protozoan parasites. In humans, PRLs are involved in metastatic cancer, the promotion of cell migration and invasion. PTPs have been increasingly recognized as important effectors of host-pathogen interactions. We characterized the only putative protein tyrosine phosphatase PRL (PTP EhPRL) in the eukaryotic human intestinal parasite Entamoeba histolytica. Here, we reported that the EhPRL protein possessed the classical HCX5R catalytic motif of PTPs and the CAAX box characteristic of the PRL family and exhibited 31-32% homology with the three human PRL isoforms. In amebae, the protein was expressed at low but detectable levels. The recombinant protein (rEhPRL) had enzymatic activity with the 3-o-methyl fluorescein phosphate (OMFP) substrate; this enzymatic activity was inhibited by the PTP inhibitor o-vanadate. Using immunofluorescence we showed that native EhPRL was localized to the cytoplasm and plasma membrane. When the trophozoites interacted with collagen, EhPRL relocalized over time to vesicle-like structures. Interaction with fibronectin increased the presence of the enzyme in the cytoplasm. Using RT-PCR, we demonstrated that EhPRL mRNA expression was upregulated when the trophozoites interacted with collagen but not with fibronectin. Trophozoites recovered from amoebic liver abscesses showed higher EhPRL mRNA expression levels than normal trophozoites. These results strongly suggest that EhPRL may play an important role in the biology and adaptive response of the parasite to the host environment during amoebic liver abscess development, thereby participating in the pathogenic mechanism.

Amebic liver abscess in rat: morphological evidence of innate immune modulation by the sympathetic nervous system / Absceso hepático amebiano en rata: evidencia morfológica de la modulación de la respuesta inmune innata por el sistema nervioso simpático

All organs of the immune system are innervated and almost all neurotransmitter receptors are present on immune cells. We studied the effects of sympathetic innervation in the development of amebic liver abscess (ALA) in rats. Our results showed that lack of sympathetic innervation promote a decrease in size of ALA. We found scarce amoebas, increased the number of neutrophils and a few collagen fibers surrounding the abscess, meanwhile in control group, we observed abscesses areas with typical necrosis including trophozoites and neutrophils. Macrophages were differentially distributed surrounding abscess area in control and vehicle groups, but equally located in and outside of the abscesses in sympathectomized rat. No significant differences were observed on NK cells in analysed groups. In cytokines quantification studies, we observed down-expression of IFN-g and TNF-a, moreover, we found overexpression of IL-10 in sympathectomized and ALA group. In conclusion, our results suggest that elimination of sympathetic nerve fibers in a model rat of amebic liver abscess induces reduction of the innate immune response and presence of amebas through the liver at seven days post-inoculation.

Todos los órganos del sistema inmune están inervados y casi todos los receptores para neurotransmisores están presentes en las células de la respuesta inmune. Nosotros estudiamos el efecto de la inervación simpática en el desarrollo del Absceso Hepático Amebiano (AHA) en ratas. Nuestros resultados muestran que la inervación simpática promueve una disminución en el tamaño del AHA. Nosotros encontramos áreas fibróticas bien definidas con algunas amibas, mayor número de neutrófilos y pocas fibras de colágena rodeando el área de daño, mientras que en el grupo control, nosotros observamos áreas con necrosis, trofozoítos y pocos neutrófilos en el área fibrótica. Los macrófagos se observaron distribuidos en el área fibrótica en los animales simpatectomizados, mientras que en los controles encontramos a los macrófagos distribuidos en la periferia del absceso. No se encontró diferencia significativa en la distribución y cantidad de células NK. En el estudio de citocinas nosotros observamos una disminución de IFN-g y TNF-a y un incremento de IL-10 en animales simpatectomizados. En conclusión, nuestros resultados sugieren que la eliminación de las fibras del sistema nervioso simpático en el modelo de AHA en rata, reduce la respuesta inmune innata y persisten amebas en el tejido dañados a los 7 días post-inoculación.

Ameboma del recto con absceso hepático asociado: reporte de un caso / Case Report of Rectal Ameboma with Associated Liver Abscess

La infección por Entamoeba histolytica sigue siendo un problema mayor de salud pública en los países en desarrollo como Colombia. Aunque en la gran mayoría de casos se presenta como una disentería o un absceso hepático amebiano, existen casos donde la evolución genera una verdadera masa inflamatoria en el colon llamada ameboma. Estos amebomas son fácilmente confundidos con una lesión neoplásica y, de no tener un gran nivel de sospecha clínica o endoscópica, terminan en una resección de colon con un diagnóstico posoperatorio dado por la presencia de trofozoítos sin malignidad. Sin embargo, cuando el diagnóstico se hace de manera preoperatoria, podría haber resolución del cuadro sin necesidad de cirugía. Exponemos el caso de una rara presentación de ameboma en el recto asociado con un absceso hepático perforado, en el cual se hizo un diagnóstico preoperatorio, pero dada la ruptura de la lesión en el hígado, requirió de una intervención quirúrgica.

Entamoeba histolytica infections continue to be a major public health problem in developing countries such as Colombia. Although it most often presents as dysentery or amebic liver abscess, there are cases in which a true inflammatory mass develops in the colon. This is called an ameboma. These amebomas are easily confused with neoplastic lesions so that in the absence of a high level of clinical and endoscopic suspicion, a colon resection may be performed with the postoperative diagnosis given by the presence of trophozoites without malignancy. However, when the diagnosis is made preoperatively symptoms can be without surgery. We report a rare presentation of ameboma in the rectum associated with a perforated liver abscess. This was diagnosed prior to surgey, but given the liver injury, required surgery.

Absceso hepático amebiano: Presentación de caso / Amebic liver abscess: Case report

El absceso hepático amebiano (AHA) es la manifestación extraintestinal más frecuente de la amebiasis. El AHA es resultado de la invasión de Entamoeba histolytica al hígado. Es una infección que está asociada a las malas condiciones de saneamiento ambiental y a los deficientes hábitos higiénicos. Es una patología que aún sigue presentado una alta morbilidad. En este artículo se informa un caso clínico y seguimiento de un paciente de 23 años con AHA, quien presenta la sintomatología típica a quien se suministra tratamiento etiológico adecuado. Adicionalmente, se realiza una revisión sobre el tema abordando los aspectos epidemiológicos más relevantes.

Amebic liver abscess (ALA) is the most common extraintestinal manifestation of amebiasis. The AlA is a result of the invasion of Entamoeba histolytica in the liver. It is an infection that is associated with poor environmental sanitation and poor hygiene. It is a disease that is still presented a high morbidity. This article presents a case report and track a patient aged 23 with ALA, who has the typical symptoms who provided adequate etiological treatment is reported. Additionally, a review of the subject is done by addressing the most relevant epidemiological aspects.

Estudio y tratamiento de los abscesos hepáticos / Study and treatment of liver abscesses

Liver abscess is an unusual but potentially lethal disease. We should be especially cautious in patients diagnosed with biliary pathology or immunosuppression, with right upper quadrant pain, fever or jaundice. The study should include images, cultures and serology for Entamoeba histolytica in certain scenarios. The treatment of pyogenic liver abscess is based on prolonged antibiotic therapy and usually in the drainage of the collection, which can be percutaneous, open or endoscopic. In case of amoebic liver abscesses, drug treatment -in two phases- achieve the parasitic removal at tissue and luminal levels, keeping the drain choice for larger abscesses.

El absceso hepático es una patología poco prevalente pero potencialmente letal. Se debe tener una alta sospecha en pacientes con patología de la vía biliar o inmunosupresión, que presenten dolor en hipocondrio derecho, fiebre o ictericia. El estudio debe incluir imágenes, cultivos y eventualmente serología para Entamoeba histolytica en determinados escenarios. El tratamiento de los abscesos hepáticos piógenos se basa en antibioterapia prolongada y habitualmente en el drenaje de la colección, el cuál puede ser percutáneo, abierto o endoscópico. En el caso de los abscesos hepáticos amebianos el tratamiento farmacológico, en dos fases, logra la eliminación parasitaria a nivel tisular y luminal, reservando el drenaje para los de gran tamaño.

Absceso hepático amebiano en el embarazo: reporte de un caso / Amebic liver abscess in pregnancy: a case report

La asociación de absceso hepático amebiano y embarazo es poco frecuente y se asocia a un aumento de la morbilidad y mortalidad materna. Presentamos el caso de una paciente de 33 años, cursando un embarazo de 35 semanas, que ingresó a nuestro servicio con el diagnóstico de absceso hepático, cuya etiología fue E. histolytica.

The appearance of amebic liver abscess in pregnancy is uncommon and is associated to increased maternal morbidity and mortality. We report the case of 33 years old woman, with a 35 weeks pregnancy that was admitted in our Hospital with the diagnosis of liver abscess, whose etiology was E. histolytica.