IgG Autoantibodies Induced by T. cruzi During Pregnancy: Correlation with Gravidity Complications and Early Outcome Assessment of the Newborns.

Objective The aim of the present research was to evaluate the correlation of vertically transmitted IgG antibodies induced by T. cruzi and newborn early outcome assessment, mainly birth weight and gestational age. Methods We performed a cross-sectional study with 183 pregnant women (64 with asymptomatic Chagas disease) and their newborns. Both were subjected to complete clinical examination. Peripheral parasitemia was assessed in mother and neonates by parasite detection through microscopic examination of the buffycoat from mother's peripheral and cord blood. Antibodies induced by T. cruzi, such as anti-FRA, anti-B13, anti-p2ß and anti-T. cruzi were assessed by immunoassay. Birth weight, general condition evaluation by APGAR Score and gestational age by Capurro Score, were determined in newborns. Results The rate of stillbirth background and pregnancy-induced hypertension were higher in patients with Chagas disease (p = 0.01 and p = 0.02, respectively). Parasitemia was detectable in 17 mothers and 4 newborns. The newborns of mothers with detectable parasitemia presented decreased gestational age (p = 0.006) and body weight (p = 0.04). Mostly all the mothers with Chagas disease and all their newborns have positive values of antibodies induced by T. cruzi; however, only anti-p2ß showed to be related to the presence of complication during pregnancy (OR 2.35, p = 0.036), and to low birth weight (OR 1.55, p = 0.02). Conclusions Low birth weight and decreased postnatal estimation of maturity were related to detectable parasitemia in the mother. Also, vertical transmission of T. cruzi-induced autoantibodies might have clinical implication in newborns given the negative association between anti-p2ß values and weight.

Parasitic Effects on the Congenital Transmission of Trypanosoma cruzi in Mother-Newborn Pairs.

Maternal parasitemia and placental parasite load were examined in mother-newborn pairs to determine their effect on the congenital transmission of Trypanosoma cruzi. Parasitemia was qualitatively assessed in mothers and newborns by the microhematocrit test; parasite load was determined in the placental tissues of transmitting and non-transmitting mothers by the detection of T. cruzi DNA and by histology. Compared to transmitter mothers, the frequency and prevalence of parasitemia were found to be increased in non-transmitter mothers; however, the frequency and prevalence of parasite load were higher among the transmitter mothers than among their non-transmitter counterparts. Additionally, serum levels of interferon (IFN)-γ were measured by an enzyme-linked immunosorbent assay (ELISA) in peripheral, placental, and cord blood samples. Median values of IFN-γ were significantly increased in the cord blood of uninfected newborns. The median IFN-γ values of transmitter and non-transmitter mothers were not significantly different; however, non-transmitter mothers had the highest total IFN-γ production among the group of mothers. Collectively, the results of this study suggest that the anti-T. cruzi immune response occurring in the placenta and cord is under the influence of the cytokines from the mother's blood and results in the control of parasitemia in uninfected newborns.

Frequency of Gastrointestinal Parasites, Anemia, and Nutritional Status among Children from Different Geographical Regions of Bolivia.

The study aimed to measure the frequency of occurrence of infections with helminths, protozoa, and risk factors of undernutrition and anemia among schoolchildren from the Bolivian highland (altiplano) and lowland (subtropical) rural regions, with a high frequency of gastrointestinal parasite infections. Cross-sectional data were collected from 790 children, 5-13 years old. Microscopic examination of stool using the Ritchie technique, hemoglobin testing using the HemoCue analyzer, and anthropometric measurements were performed. Over 60% and 20% of children were infected with protozoa and helminth parasites, respectively. Infections caused by pathogenic Hymenolepis nana (15.7-5.2%), Ascaris lumbricoides (41.9-28.5%), Giardia lamblia (30.1-11.2%), Entamoeba histolytica (5.7-0.7%), and nonpathogenic Entamoeba coli (48.9-16%), Blastocystis hominis (40.2-28.5%), Iodamoeba butschli (16.1-2.5%), Chilomastix mesnili (19.2-7.3%), and Entamoeba histolytica/dispar (7.4-5.5%) parasites, were more prevalent in the highlands than the lowlands. Single parasitic infections were more prevalent in the lowlands; polyparasitism of light or heavy intensity predominated in the highlands. A strongly increased risk of anemia and a low prevalence of wasting were determined in children in the highlands. A higher risk for stunting was associated with children of older age, and a low burden of intestinal helminths would prevent wasting in children of highlands. Infections with A. lumbricoides and G. lamblia pathogens in older children were not significant covariates for stunting. Environmental, nutritional, and parasitic factors may predispose to anemia in the highlands. A nutritional intervention and parasite control effort will substantially improve children´s health in the highlands.

Differences in Nutritional and Health Status in School Children from the Highlands and Lowlands of Bolivia.

Children in the Bolivian Andes are exposed to endemic infections and meager nourishment, and live under poor hygienic conditions. The prevention of children malnutrition is a priority in many countries including Bolivia. In this study, the health status of schoolchildren in Taraco, a Puna district, at 4,000 meters above sea level (masl) and in Caranavi, at 650 masl in the wealthier subtropical valleys, was compared. The weight, height, and hematological and biochemical parameters in blood, parasites in stool, and clinical information in 120 children from rural Taraco and in 96 from semi-urban Caranavi, both predominantly of Aymara ethnicity, were registered. Eleven percent of Taraco children were undernourished compared with 3% in Caranavi. Instead, 41% of the children in Caranavi were obese or overweight, compared with 8% in Taraco. Anemia was found in 74% of the children in Taraco compared with 7% in Caranavi. Albumin levels were normal in all samples, albeit lower in Taraco. Similar and normal serum zinc levels were measured in both groups. Approximately 60% of the children in both locations showed insufficient vitamin D levels, with lower levels in Taraco children. Hymenolepis nana and Entamoeba coli, parasites determinant of poor hygienic conditions, were respectively detected in 78% and 21% of fecal samples from Taraco, and in 29% and 8% of samples from Caranavi. We show increased anemia, nutritional deficiencies, and indications of poor hygienic conditions in highlands compared with lowlands. The prevalence of obesity in the lowlands demands addressing diverse nutritional deficiencies in the regions of Bolivia.

Pro-inflammatory cytokine production in chagasic mothers and their uninfected newborns.

The levels of IFN-gamma, TNF-alpha, IL-10, and TGF-beta1 cytokines associated with Trypanosoma cruzi during pregnancy were determined by enzyme-linked immunosorbent assay (ELISA) in serum samples from peripheral, placental, and cord blood of chronic infected mothers with detectable and undetectable parasitemia, and in their uninfected newborns. Compared to uninfected pregnant women and mothers with undetectable parasitemia, the concentrations of IFN-gamma were higher at the 3 sites in mothers with detectable parasitemia. In these mothers and their newborns, the TNF-alpha concentrations were higher in the periphery and cord in comparison to serum samples from non-chagasic pregnant women. TNF-alpha levels were higher in newborns of mothers with detectable parasitemia than in newborns of mothers with undetectable parasitemia. IL-10 and TGF-beta1 levels at the 3 sites were unchanged and diminished, respectively, in samples from infected mothers with patent parasitemia in comparison with uninfected pregnant women. Cytokine concentrations did not change significantly in all samples from mothers with undetectable parasitemia; however, the concentration of TGF-beta1 was significantly reduced in their peripheral samples but significantly higher in the placenta in comparison with uninfected mothers and mothers with detectable parasitemia, respectively. These results suggest that elevated numbers of circulating parasites in vivo elicit production of pro-inflammatory cytokines that control congenital T. cruzi infection.

Enhancement of a TH1 immune response in amphotericin B-treated mucocutaneous leishmaniasis.

In an attempt to investigate the effects of treatment of human leishmaniasis, the cytokines produced by peripheral blood mononuclear cells (PBMCs) of patients with cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL) under treatment with amphotericin B were determined during the active disease from cocultures of cells and Leishmania (Viannia) braziliensis antigens. PBMC of these patients exhibited a nonsignificant marginal increased production of TNF-alpha upon antigen stimulation. However, under the same antigenic stimulus, patients with active MCL presented higher IFN-gamma production compared to patients with CL. This increased IFN-gamma production was accompanied by a drastically augmented IL-12 synthesis from cells of MCL patients. The highlighted T cell responses could be relevant for sound control measures of protozoan infections with emphasis on the combined usage of immunoenhancing agents and antiprotozoal drugs.

Ausencia de capacidad tripanocida en macrofagos de apcients chagasicos / absebce of tripanocidal capacity in macrophages of chagasic patients

Pregunta de investigaciòn: ¿Cuàl es el comportamiento de macròfagos de pacientes chagàsicos frente a cutokinas individuales?. Objetivos: Determinar el efecto de IL-2, IL-4 TNF-alpha, IFN-gamma, M-CSF, y GM-CSF en la interacciòn de macaròfagos y Trypanosoma cruzi. Diseño. Experimental en controles y pacientes. Lugar. Instituto Boliviano de Biología de Altura, Faucltad de Meidicina, UMSA. Población. Veinte pacientes chagàsicos con serología positiva para T. cruzi (inmunofluorescencia y ELISA). Diez donadores sanos con relogia negaiva para T. cruzi. Métodos. Células mononucleares periféricos fueron separadas medniante gradiente de densidad (Ficoll Hypaque). Los monocitos fueron recuperados por adhesión en placas de vidrio y cultivados en presencia de parásitos. Luego de 2 hs se eliminaron parásitos libres y se incubaron los cultivos con cytokinas durante 48 hs. Se analizaron no menos de 200 células microscópicamente en cada condición para detrminar multiplicación o desnutrición de parásitos . Resultados. Solamente las células de donadores sanos respnden al estimulo de GM-CSF e IL-4 como se evidencia por una reducción significativa del número de parásitos y porcentaje de células parasitadas.

Characterization of T cell clones from chagasic patients: predominance of CD8 surface phenotype in clones from patients with pathology

Human Chagas' disease, caused by the protozoan Trypanosoma cruzi, is associated with pathological processes whose mechanisms are not known. To address this question, T cell lines were developed from chronic chagasic patients peripheral blood mononuclear cells (PBMC) and cloned. These T cell clones (TCC) were analyzed phenotypically with monoclonal antibodies by the use of a fluorescence microscope. The surface phenotype of the TCC from the asymptomatic patient were predominantly CD4 positive (86 por cento). On the contrary, the surface phenotype CD8 was predominant in the TCC from the patients suffering from cardiomegaly with right bundle branch block (83 por cento), bradycardia with megacolon (75 por cento) and bradycardia (75 por cento). Future studies will be developed in order to identify the antigens eliciting these T cell subpopulations.

Obtención y caracterización de clones de leshmania para la producción de antígeno / Production and characterization of leshmania clones for antigen production

Objetivos: Producción de leishmanina. Lugar. Intituto Boliviano de Biología de Altura, Facultad de Medicina, UMSA. Diseño. Experimental. Métodos. Una capa nativa (MHOM/BO/89EQ) y una cepa de referencia de OMS (MHOM/BR/75 2903) amsas correspondientes a Leishmania braziliensis braziliensis, fueron clonadas y cultivadas durante 7 días,la recolección de formas promastigotes se realizó en fase exponencial de crecimiento. Luego de fijación de parásitos el antigeno fué evaluado en un test de linfoproliferación con células de paciaentes con leishmania cutanea, In vivo, se realizó en hamsters y ratones, el tamaño de la lesión, desarrollo de metástasis, toxicidad anormal y diametro de induración. Resultados. El diámetro de induración obtenido en hambsters fué de 8 mm, 7.5 mm en ratones con la lesihmanina dae la cepa nativa EQ, con la cepa de refernecia 2903, en hamster fue de 7.6 mm y en ratones 8.25 mm. En pacientes con leishmaniasis se ha obtenido 75.67 por ciento y 76.19 por ciento de positividad en pacients conlesiones cutáneas y lesiones mucosas, respectivamente. La correlación cone l diagnóstico parsitológico es de 97 por ciento.