Revisión sistemática de la exactitud diagnóstica de la gota gruesa en comparación con la reacción en cadena de la polimerasa para malaria asociada al embarazo, 2010-2022 / Systematic review of the diagnostic accuracy of thick smear compared to polymerase chain reaction for pregnancy-associated malaria, 2010-2022

RESUMEN Objetivos. Evaluar la exactitud de gota gruesa (GG) frente a la reacción en cadena de la polimerasa (PCR) cuantitativa para la malaria asociada al embarazo (MAE). Materiales y métodos. Se realizó una revisión sistemática de pruebas diagnósticas en nueve bases de datos. Se evaluó la calidad metodológica con QUADAS. Se estimó sensibilidad, especificidad, cociente de probabilidad positivo (CPP) y negativo (CPN), razón de odds diagnóstica (ORD) y área bajo la curva ROC. Se determinó la heterogeneidad con el estadístico Q de Der Simonian-Laird y la incertidumbre con el porcentaje de peso de cada estudio sobre el resultado global. Resultados. Se incluyeron diez estudios con 5691 gestantes, 1415 placentas y 84 neonatos. En los estudios con nPCR (PCR anidada) y qPCR (PCR cuantitativa) como estándar, los resultados de exactitud diagnóstica fueron estadísticamente similares, con sensibilidad muy baja (50 y 54%, respectivamente), alta especificidad (99% en ambos casos), alto CPP y deficiente CPN. Usando nPCR la OR diagnóstica fue 162 (IC95%=66-401) y el área bajo la curva ROC fue 95%, mientras que con qPCR fueron 231 (IC95%=27-1951) y 78%, respectivamente. Conclusiones. Mediante un protocolo exhaustivo se demostró el bajo desarrollo de investigaciones sobre la exactitud diagnóstica de la GG en MAE. Se demostró que la microscopía tiene un desempeño deficiente para el diagnóstico de infecciones asintomáticas o de baja parasitemia, lo que afianza la importancia de implementar otro tipo de técnicas en el seguimiento y control de las infecciones por malaria en las gestantes, con el fin de lograr el control y posible eliminación de la MAE.

ABSTRACT Objective. To evaluate the accuracy of thick smear (TS) versus quantitative polymerase chain reaction (PCR) for pregnancy-associated malaria (PAM). Materials and methods. We carried out a systematic review of diagnostic tests in nine databases. Methodological quality was evaluated with QUADAS. Sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the ROC curve were estimated. Heterogeneity was determined with the Der Simonian-Laird Q method and uncertainty with the weighted percentage of each study on the overall result. Results. We included 10 studies with 5691 pregnant women, 1415 placentas and 84 neonates. In the studies with nested PCR (nPCR) and quantitative PCR (qPCR) as the standard, the diagnostic accuracy results were statistically similar, with very low sensitivity (50 and 54%, respectively), high specificity (99% in both cases), high PLR and poor NLR. When nPCR was used, the DOR was 162 (95%CI=66-401) and the area under the ROC curve was 95%, while with qPCR it was 231 (95%CI=27-1951) and 78%, respectively. Conclusions. We demonstrated that research on the diagnostic accuracy of TS in PAM is limited. Microscopy showed poor performance in the diagnosis of asymptomatic or low parasitemia infections, which reinforces the importance of implementing other types of techniques for the follow-up and control of malaria infections in pregnant women, in order to achieve the control and possible elimination of PAM.

PCR em tempo real no diagnóstico da toxoplasmose congênita / Real-time PCR in the diagnosis of congenital toxoplasmosis

O diagnóstico da toxoplasmose congênita apresenta limitações sendo, portanto, necessárias novas opções de exames. A análise do líquido aminiótico pela PCR em tempo real já se mostrou eficaz para confirmação da infecção fetal. No entanto, o seu desempenho em outras amostras biológicas ainda não está claro. O objetivo deste estudo é avaliar a PCR em tempo real no sangue da mãe e do recém-nascido assim como no líquido amniótico e placenta, no diagnóstico da toxoplasmose congênita. Esse é um estudo descritivo de gestantes com toxoplasmose acompanhadas no Rio de Janeiro, Brasil. Foi realizada PCR em tempo real em amostras de sangue materno, líquido amniótico, placenta e sangue dos recém-nascidos e o exame histopatológico das placentas. Também foram coletados dados clínicos e laboratoriais dos recém-nascidos. Foram acompanhadas 116 gestantes e analisadas 298 amostras. Uma (0,9%) gestante apresentou PCR positiva no sangue, três (3,5%) no líquido amniótico, uma (2,3%) na placenta e nenhum recém-nascido apresentou PCR positiva no sangue. O estudo histopatológico foi sugestivo de infecção por toxoplasmose em 24 (49%) placentas. Seis (5,2%) recém-nascidos foram diagnosticados com toxoplasmose congênita e apenas os casos com PCR positiva no líquido amniótico tinham associação do resultado da PCR com o diagnóstico de infecção congênita. Tanto as amostras de sangue materno quanto as de sangue dos recém-nascidos e placenta, não demonstraram ser promissoras no diagnóstico da toxoplasmose congênita. Novos estudos são necessários para avaliar o real papel do diagnóstico molecular em outros materiais biológicos que não o líquido amniótico.

The diagnosis of congenital toxoplasmosis has limitations so new options are needed. Real-time PCR analysis of amniotic fluid has proven effective for confirming fetal infection. However, its performance in other biological samples still needs to be determined. This study aims to evaluate the real-time PCR role in the blood of the mother and newborn as well as in the amniotic fluid and placenta, in congenital toxoplasmosis diagnosis. It is a descriptive study of pregnant women with toxoplasmosis followed in Rio de Janeiro, Brazil. Real-time PCR was performed on maternal blood, amniotic fluid, placenta, and newborn blood samples. In addition, a histopathological examination of the placentas was performed and data from the babies were collected. One hundred and sixteen pregnant women were followed and 298 samples were analyzed. One (0.9%) pregnant woman had positive PCR in the blood, three (3.5%) in the amniotic fluid, one (2.3%) in the placenta, and any newborn had positive PCR in the blood. The histopathological study suggested toxoplasmosis infection in 24 (49%) placentas. Six (5.2%) newborns were diagnosed with congenital toxoplasmosis and only the cases with positive PCR in amniotic fluid associated with the diagnosis of congenital infection. Neither maternal nor newborn blood and placenta samples have not shown promise in diagnosing congenital toxoplasmosis. Further studies are needed to evaluate the fundamental role of molecular diagnostics in others biological materials than amniotic fluid.

Malaria placentaria submicroscópica: histopatología y expresión de mediadores de procesos fisiológicos / Submicroscopic placental malaria: histopathology and expression of physiological process mediators

RESUMEN Objetivos: Relacionar entre sí los eventos histopatológicos de malaria placentaria (MP), el comportamiento de células inmunitarias y la expresión de genes asociados a citoquinas, hipoxia, inflamación y angiogénesis en placentas con o sin infección plasmodial. Materiales y métodos: Diseño transversal, con tres grupos independientes. Las mujeres y sus placentas fueron captadas en 2009-2016, en los hospitales de Puerto Libertador y Tierralta, noroccidente de Colombia. El tamaño muestral se definió por conveniencia. El diagnóstico malárico se basó en PCR cuantitativa en tiempo real. Resultados: Se estudiaron 20 casos con MP por P. vivax (MP-V), 20 casos de MP por P. falciparum (MP-F) y 19 sin MP; 95% de los casos de MP son infección plasmodial placentaria submicroscópica (IPPS). Los tres grupos difieren en frecuencia y cantidad de eventos histopatológicos. Los mediadores de procesos fisiológicos presentaron diferencia significativa entre grupos, excepto IL-2, VEGF, VEGFR-1 y C5a. Conclusiones: Las placentas con infección difieren claramente de las no infectadas. P. vivax se comporta tan patógeno como P. falciparum. Se resalta la aproximación al abordaje integral del problema de MP. La infección plasmodial placentaria submicroscópica causa alteraciones tisulares y en mediadores fisiológicos como lo hace la infección microscópica, aunque probablemente en menor grado.

ABSTRACT Objetives: To relate histopathological events of placental malaria (PM), immune cell behavior and gene expression associated with cytokines, hypoxia, inflammation and angiogenesis in placentas with or without plasmodial infection. Materials and methods: Transversal design, with three independent groups. Women were recruited, and their placentas were collected in 2009-2016, in the hospitals of Puerto Libertador and Tierralta, northwestern Colombia. The sample size was defined by convenience. The malaria diagnosis was based on real-time quantitative PCR. Results: We studied 20 cases of PM by P. vivax (PM-V), 20 cases of PM by P. falciparum (PM-F) and 19 without PM; 95% of the cases of PM are submicroscopic placental plasmodial infection (SPPI). The three groups differ in frequency and number of histopathological events. Physiological process mediators showed significant difference between groups, except IL-2, VEGF, VEGFR-1 and C5a. Conclusions: Infected placentas are clearly different from uninfected ones. P. vivax behaves as pathogenic as P. falciparum. The approximation to the integral approach of the problem of PM is underlined. Submicroscopic placental plasmodial infection causes tissue and physiological mediator alterations as does microscopic infection, although probably to a lesser degree.

Consecuencias de la infección malárica gestacional en la función inmune y en la inmunomodulación de la madre y el neonato / Consequences of gestational malaria infection in the immune function and immunomodulation of mother and newborn

Resumen La malaria asociada al embarazo es un evento poco estudiado en América Latina. Los abundantes trabajos sobre el problema en África llevan a pensar que esta infección genera una modulación de la respuesta inmune y alteraciones en el ambiente placentario, eventos cruciales para el adecuado desarrollo del feto y el neonato. La inmunidad contra Plasmodium spp es compleja porque involucra diversos factores que amplían las posibilidades de desenlaces, los que finalmente conducen a los diferentes fenotipos clínicos de la enfermedad. Uno de los desenlaces inmunológicos en infecciones por Plasmodium spp es la modulación de la respuesta inmune hacía un perfil regulador. Esta regulación inducida por la infección malárica resulta ventajosa para la persistencia del parásito en el hospedero, y adicionalmente, podría generar eventos adversos en la respuesta inmune general de los individuos infectados. El objetivo de esta revisión es abordar los mecanismos con los cuales Plasmodium spp modula la respuesta inmune del hospedero y exponer las consecuencias de las infecciones maláricas en el contexto madre-neonato.

Pregnancy-associated malaria is an understudied event in Latin America. Most works about malaria in pregnancy have been conducted in Africa. These studies indicate that the infection generates immune response modulation and alterations in the placental environment, key factors for the proper development of the fetus and neonate. Immunity against Plasmodium spp is complex since involves several factors that increase the possible infection outcomes. One of these immunological outcomes is the immune response modulation towards a regulatory profile, which is advantageous for the persistence of the parasite in the host; additionally, it could generate adverse events in the general immune response of infected individuals. The objective of this review is to address the Plasmodium spp mechanisms of modulation in the host immune response and expose the consequences of malarial infections in the mother-neonate context.

Glicosaminoglicanos como posibles reguladores de inflamación durante la malaria placentaria / Glycosaminoglycans as potential regulators of inflammation during placental malaria

Los mecanismos fisiopatológicos de la malaria placentaria son hasta el momento poco comprendidos, y el daño placentario derivado de la infección por Plasmodium spp se ha relacionado con eventos adversos del embarazo que afectan directamente el desarrollo del feto. Las concentraciones placentarias de algunas citocinas como la IL-10, TNF-alfa y TGF-beta y glicosaminoglicanos como el CSA, HA y HS podrían estar participando de forma reguladora en los eventos inflamatorios placentarios durante la infección por Plasmodium spp.

The pathophysiological mechanisms of placental malaria are until now poorly understood and the placental damage resulting from infection by Plasmodium spp has been linked to adverse pregnancy events that directly affect fetal development. Placental concentrations of some cytokines such as IL-10, TNF-alpha and TGF-beta and glycosaminoglycans such as CSA, HA and HS could be involved in a regulatory role in placental inflammation during infection by Plasmodium spp.

Anticorpos anti-neospora caninum em bovinos de leite do sudoeste do estado do Paraná / Antibodies to neospora caninum in dairy cattle in Southwest of Paraná state

Since November 2007 until May 2009, 1,778 serum samples of cattle from dairy herds of the Southwest of Paraná State, Brazil, were used for search of anti-Neospora caninum antibodies. The frequency of seropositive animals, assessed by IFAT, was 24.2 percent (431/1,178), showing a relatively high occurrence in the studied population. These results show that Neospora caninum is widely distributed in the dairy cattle in the Southwest of Paraná State. The presence of Neospora caninum in a herd is worrisome, since this protozoan is closely related with reproductive disorders and low milk production in cattle.

Vertical transmission of Trypanosoma cruzi in the Province of Choapa, IV Region, Chile: Preliminary Report (2005-2008)

Congenital Chagas disease acquired special importance in Chile after the certification of the control of Triatoma infestans and transmission by blood donors affected with Trypanosoma cruzi. In order to establish adequate protocols for intervention and control in infected mother-neonate pairs in endemic zones of Chagas disease, we present partial results (2005-2008) of a pilot project which is being carried out in the Province of Choapa, IV Region, Chile, whose objectives are: determine the current prevalence of the disease in pregnant women, estimate the incidence of vertical transmission of T. cruzi to newborns, determine the lineages of the parasite present in mothers who do and do not transmit the disease, determine the prevalence of Chagas disease in maternal grandmothers of neonates and study placental histopathology. Preliminary results indicated that in this study period, 3.7 percent of the women who gave birth in the Province have Chagas disease and 2.5 percent of their newborns were infected. The most frequent T. cruzi genotypes found in mothers studied during pregnancy were TCI and TCIId, either alone or in mixed infections. A high percentage (74.3 percent) of the grandmothers studied was infected with the parasite. In 29 placentas from mothers with Chagas disease we observed edema, necrosis, fibrinoid deposits and slight lymphoplasmocyte infiltration. In three placentas we found erythroblastosis and in one of them amastigote forms of T. cruzi; this was one of the cases of congenital infection. The evaluation of the diagnostic and control protocols generated will allow us to determine if it has been possible to modify the natural history of vertical transmission of T. cruzi in Chile.

Infection and invasion mechanisms of Trypanosoma cruzi in the congenital transmission of Chagas' disease: A proposal

Chagas' disease is produced by the haemophlagelated protozoan Trypanosoma cruzi and transmitted by haematophages insects such as Triatoma infestans (vinchuca). Due to vector control, congenital transmission gains importance and is responsible for the presence and expansion of this disease in non-endemic areas. The mechanisms of congenital infection are uncertain. It has been suggested that the parasite reaches the fetus through the bloodstream by crossing the placental barrier, and that congenital Chagas' disease is the result of complex interactions between the immune response, placental factors, and the parasite's characteristics. We review the cellular and molecular mechanisms of infection and invasion of the parasite and how immune and placental factors may modulate this process. Finally, we propose a possible model for the vertical transmission of Chagas' disease.

Molecular and pathological study of bovine aborted fetuses and placenta from Neospora caninum infected dairy cattle

The objective of the study was to evaluate the presence of Neospora caninum organisms in the brain of aborted fetuses and placentas of full-term calves born of seropositive cows. During 2006-2007, 12 brains of aborted calves from Neospora seropositive cattle and 7 placentas from seropositive dams giving birth to full-term calves, from four dairy cattle farms located around Tehran province, Iran were examined by Nested-PCR and histopathology techniques. The Nested-PCR demonstrated that all of 12 aborted fetal brain samples and 5 of 7 placentas were infected by N. caninum. Mild to severe placentitis was observed in 5 placentas. Severe hyperemia and perivascular and perineuronal edema revealed in all fetal brain. In 3 out of 12 brains, scattered foci of hemorrhages, neuropilar necrosis and gliosis were present. In addition, nonpurulent encephalitis with severe lymphohistiocytic perivascular cuffing in one case and a small tissue cyst like Neospora caninum cyst in other calf were observed. Our results confirmed the molecular and histopathologic findings of other studies about Neospora caninum infection and it seems to support the hypothesis that Neospora infection is associated with bovine abortion in Iran

Cytoadhesion of Plasmodium falciparum-infected erythrocytes and the infected placenta: a two-way pathway

Malaria is undoubtedly the world's most devastating parasitic disease, affecting 300 to 500 million people every year. Some cases of Plasmodium falciparum infection progress to the deadly forms of the disease responsible for 1 to 3 million deaths annually. P. falciparum-infected erythrocytes adhere to host receptors in the deep microvasculature of several organs. The cytoadhesion of infected erythrocytes to placental syncytiotrophoblast receptors leads to pregnancy-associated malaria (PAM). This specific maternal-fetal syndrome causes maternal anemia, low birth weight and the death of 62,000 to 363,000 infants per year in sub-Saharan Africa, and thus has a poor outcome for both mother and fetus. However, PAM and non-PAM parasites have been shown to differ antigenically and genetically. After multiple pregnancies, women from different geographical areas develop adhesion-blocking antibodies that protect against placental parasitemia and clinical symptoms of PAM. The recent description of a new parasite ligand encoded by the var2CSA gene as the only gene up-regulated in PAM parasites renders the development of an anti-PAM vaccine more feasible. The search for a vaccine to prevent P. falciparum sequestration in the placenta by eliciting adhesion-blocking antibodies and a cellular immune response, and the development of new methods for evaluating such antibodies should be key priorities in mother-child health programs in areas of endemic malaria. This review summarizes the main molecular, immunological and physiopathological aspects of PAM, including findings related to new targets in the P. falciparum var gene family. Finally, we focus on a new methodology for mimicking cytoadhesion under blood flow conditions in human placental tissue.

Factores y mecanismos involucrados en la transmissión y el desarollo de la infección congénita por Trypanosoma cruzi / Factors and mechanisms involved in the transmission and development of congenital infection with Trypanosoma cruzi

This paper synthesizes the results obtained from multidisciplinary studies of Bolivian cases of congenital infection with T. cruzi. Congenital infection and congenital Chagas disease do not result from transmission of a particular strain of parasite, but from an equilibrium between complex phenomena, such as a weak maternal type 1 adaptative immune response associated with high maternal parasitemia, an invasion of placental chorion and umbilical cord by parasites, in front of a fetal T. cruzi-specific immune response characterized by an activation of cytotoxic CD8 T cells producing IFN-gamma and able to limit parasite multiplication and morbi-mortality of congenital Chagas disease.

Componentes celulares y fosfatasa alcalina placentaria en la infección por T. cruzi / Cellular components and placental alkaline phosphatase in Trypanosoma cruzi infection

Trypanosoma cruzi induces changes in the protein pattern of human placenta syncytiotrophoblast. Placental alkaline phosphatase (PLAP) is a glycoenzyme anchored to the membrane by a glycosyl-phosphatidylinositol molecule. PLAP activity and its presence was altered by the parasite in cultures of human placental villi and HEp2 cells with T.cruzi. The cells treated before the cultures with agents which affect PILAP or glycosyl-phosphatidylinositol (antibodies, PL-C, genistein, lithium) presented less parasitic invasion than the control ones. It was also observed a modification in the pattern of actine filaments of the host cells infected. We concluded that PLAP would participate in the process of T. cruzi invasion into placental syncitiotrophoblast cells, by a mechanism that involves hydrolysis of the glycosyl-phosphatidylinositol molecules, the activation of tyrosine kinase proteins, the increase of cytosolic calcium and the rearrangement of actine filaments of the host cells.

Las lesiones placentarias en la infección humana por Trypanosoma cruzi / Placental lesions in human Trypanosoma cruzi infection

This histopathological study analyzes placentas of babies congenitally infected with T. cruzi (M+B+), or babies not infected but born from infected- (M+B-), or non infected-mothers (M-B-). Placentas M+B+ showed lesions of chorionitis, chorioamnionitis and cord edema with lymphocyte infiltration, whereas such lesions were infiltrated only with polymorphonuclear cells in M+B- and M-B- placentas. Parasites were found in M+B+ placentas, in fibroblasts and macrophages of chorion, membranes, chorionic plate, mainly in the area of membrane insertion, as well as in cells of Wharton jelly and myocytes of umbilical cord vessels. These results suggest that the materno-fetal transmission of parasites occurs mainly through the marginal sinus, spreading into the chorionic plate infecting fibroblasts and macrophages so far as to found a fetal vessel, inducing a fetal infection by hematogenous route.

Efectos de la infección aguda y crónica por Trypanosoma cruzi en la gestación de los ratones / Effects of acute and chronic Trypanosoma cruzi infection in pregnant mice

Pathogens may impair reproduction in association or not with congenital infections. We have investigated the effect of acute infection with Trypanosoma cruzi, the protozoan agent of Chagas disease, on reproduction of female mice. In the acute, parasitemic, phase of the infection, female mice were totally unable to reproduce. Most of them (80%) were infertiles and did not develop any gestation. In the few gravid infected mice, implantation numbers were as in uninfected control mice. However, their fetuses presented a weight meanly reduced by 40% as compared to those of uninfected females, and all of them died during the gestation or whithin 48 h after birth. Such massive mortality did not result from congenital infection, which did not occur. The infertility and the fetal mortality occuring early in gestation (resorptions) were significantly correlated with a high maternal parasitemia, whereas later fetal mortality was associated with the presence of intracellular parasites in the utero-placental unit. The decidua was particularly receptive to T. cruzi multiplication, since this tissue harboured 125 fold more amastigotes than the maternal heart or other placental tissues. In addition, placentas of dead fetuses presented histopathological lesions (inflammatory infiltrates, fibrine deposits and ischemic necrosis). Such harmfull effects of acute infection were not observed when female mice were in the chronic phase of the infection, since these reproduce normally. Their fetuses only suffered from moderate and reversible growth retardation. These results indicate that, following the maternal parasite burden, T. cruzi infection may induce very deleterious effects on gestation.

Influence of placental malaria infection on foetal outcome in the Gambia: twenty years after Ian Mcgregor.

Malaria infection in pregnancy has serious health consequences among mothers and offspring. The influence of placental malaria infection on foetal outcome was studied in a Gambian rural setting where few pregnant women take antimalarial chemoprophylaxis. During July-December 1997, three hundred thirteen mother-newborn pairs (singletons only) were consecutively recruited into a study of the effects of placental malaria infection on the outcome of pregnancy. Placental blood and tissue were collected at delivery. Babies were clinically assessed until discharge. The overall prevalence of placental malaria infection was 51.1% by placental histology and 37.1% by blood smear. The primigravid women were more susceptible to placental malaria than the multigravidae (65.3% vs 44.7%, p=0.01). Placental malaria was significantly associated with pre-term deliveryand intrauterine growth retardation (p<0.01), and there was a four-fold risk of delivering low-birth-weight babies if mothers had parasitized placentae [OR=4.42, 95% confidence interval (CI) 2.10-9.27]. A reduction of mean birth-weight of babies by 320 g was associated with placental malaria infection (p<0.001). Similarly, a two-fold risk of stillbirth delivery (OR=2.22, 95% CI 1.04-4.72) was observed among the infected mothers. The findings showed that there was still an overall poor foetal outcome associated with placental malaria infection. The findings of this study confirm the findings of an earlier study by McGregor in the Gambia that the low birth-weight rate is significantly higher if the placenta is parasitized. In addition, this study observed that the high stillbirth and prematurity rates were associated with placental malaria infection. The findings of the present study suggest undertaking of effective malaria-control strategies during pregnancy, such as use of insecticide-impregnated bednets, intermittent and early treatment for malaria, and antimalarial chemoprophylaxis, in the Gambia.

possibility of transplacental transmission of experimental schistosomiasis

Congenital transmission of Schistosoma mansoni and S. hematobium in mice was studied by experimentally infected pregnant mice on day 3, 9 or 14 of gestation. None of the pups born to mothers infected in early or mid- pregnancy were infected. However, several pregnancies ended in abortion ranging between 10% to 40%. On the other hand, 8 out of 30 pups born to mice infected with S. hematobium in late pregnancy were found to harbor Schistosomes with granulomas recovered in their livers and intestines. These findings showed that congenital infection of mice with S. mansoni and S. hematobium could occur when pregnant mice were infected during late pregnancy. This may have important implications not only for mice but also for other mammalian hosts of Schistosomes including man

Schistosoma mansoni eggs in the placenta: an unusual finding

Schistosomiasis is a parasitic disease affecting millions of people in different parts of the world. It is estimated that only in Brazil 8 to 12 milion people are affected by Schistosoma mansoni, the species responsible for this disease in this country. Although its high prevalence, only rarely have S. mansoni eggs been found in the placenta. We report here a case in which the eggs were found in villous vessels during a routine examination of the placentas at our Institution. This region is not endemic for this disease and the patient did not know she had the disease

Aumento de celulas de Hofbauer en placentas humanas cocultivadas in vitro con Trypanosoma cruzi / Increment of Hofbauer cells in human placentas cocultured in vitro with Trypanosoma cruzi

Con el objetivo de analizar la interacción de placentas humanas normales con el Trypanosoma cruzi, se estudió mediante el microscopio óptico y electrónico el estroma de vellosidades coreales cocultivadas in vitro con 1,5 x 106 formas tripomastigotes de la cepa Tulahuen del Trypanosoma cruzi durantre 1h, 3hs y 12hs, en medio mínimo esencial de Eagle bajo condiciones adecuadas. Se observó en los cultivos experimentales (con T. cruzi) una aglutinación de las muestras placentarias que fue más evidente a partir de los 60 min y que resistió la separación mediante agitación suave. En el estroma de las vellosidades coriales se apreció separación de sus estructuras, edema vellositario y aumento de las células de Hofbauer de acuerdo a los análisis cuantitativos realizados. La aglutinación de las vellosidades puede deberse a modificaciones de los componentes glucoproteicos del trofoblasto por acción de productos secretados por el parásito, como ya ha sido señalado por otros autores en diversos tipos celulares. El aumento de las células de Hofbauer podría representar un mecanismo regulador de la placenta para equilibrar el nivel de agua del estroma vellositario

Demostracion de la infeccion placentaria por T. Cruzi a traves de la tecnica de inmunoperoxidasa / Demostration of transplacental infections for by T. cruzi inmunoperoxidease technique

Los autores en el presente trabajo, muestran la utilidad y especificidad de la tecnica de la inmuno-peroxidasa aplicada para la identificacion del T. Cruzi y sus formas degeneradas (exoantigenos). Tecnicas realizadas en cortes de tejido de placenta, cordon y membrana incluidos en parafina y procedentes de madres con infeccion chagasica cronica

Leiomiócitos parasitados pelo Trypanosoma Cruzi nas formas congênita e crônica adquirida da doença de Chagas / Smooth muscle cells infected by Trypanosoma Cruzi in congenital and chronic acquired forms of Chagas disease

Os leiomiócitos parassitados pelo T. cruzi, de vasos umbilicais e placentários de casos congênitos da doença de Chagas, foram comparados com células semelhantes da veia suprarrenálica de chagásicos crônicos. Observou-se que algumas destas células, em ambos os grupos, apresentavam envoltório visto à microscopia de fase, nas preparaçöes näo coradas, e à microscopia de luz comum, quando coradas pelo PAS e pela HE. A prata-metenamina cora apenas o envoltório das células parasitadas dos casos de doença de Chagas congênita. A técnica do picro-sirius, associada à microscopia de luz polarizada, mostra que ambos os grupos de leiomiócitos parasitados podem apresentar delicada membrana com birrefrigência discreta "verde limäo", enquanto que un envoltório espesso com forte birrefrigência amarelada ou brancacente é visto apenas nos leiomiócitos fetais. A técnica da peroxidase anti-peroxidase cpara T. cruzi mostra acúmulo de material PAP-positivo formando uma faixa interrompida que se coloca mais internamente à faixa PAS-positivo, em ambas as formas da doença. As modificaçöes nucleares e citoplasmáticas das células fetais parasitadas (Chagas congênito) e dos adultos (chagásicos crônicos) säo muito semelhantes, destacando-se o gigantismo nuclear, o aparecimento de grânulos algumas vezes PAP-positivo, e a desproporçäo entre o aumento do volume celular e o número de parasitas. É possível que o estado de imunodeficiência, localizado na glândula suprarrenal do adulto e o tecido fetal tenham algum papel na gênese dessa peculiaridade das células parasitadas, comuns na doença de Chagas congênita e na forma crônica adquirida