Pneumonia por toxoplasmose em paciente imunocompetente / Toxoplasma pneumonia in an immunocompetent patient: case repor

Com grande distribuição mundial e incidência significativa, a toxoplamose é uma doença comum em mamíferos e pássaros, causada pelo protozoário Toxoplasma gondii. No homem, o parasitismo na fase proliferativa intracelular pode se apresentar sem sintomas, ou causar clínica transitória caracterizada por febre, fadiga e linfadenopatia. Por se tratar de patologia com sintomas inespecíficos e comuns a muitas outras, é fundamental a correta pesquisa de diagnósticos diferenciais, como citomegalovírus e Epstein-Barr. Relatamos o caso de um jovem e hígido, que desenvolveu pneumonia e, após confirmação sorológica para toxoplasmose e o tratamento adequado, apresentou melhora clínica.

With great worldwide distribution and significant incidence, toxoplamosis is a common disease in mammals and birds, caused by the protozoan Toxoplasma gondii. In humans, the parasitism in its intracellular proliferative phase may present no symptoms, or cause a transient condition characterized by fever, fatigue, and lymphadenopathy. Because it is a pathology with nonspecific symptoms that are common to many other conditions, it is fundamental to find the correct research of differential diagnoses, such as for Cytomegalovirus and Epstein Barr. We report a case of a young and healthy man who developed pneumonia and, after serological confirmation for toxoplasmosis and the appropriate treatment, presented clinical improvement

Algunas variables epidemiológicas relacionadas con la toxoplasmosis en mujeres en edad fértil en Riobamba / Some epidemiological variables associated to toxoplasmosis in women of childbearing age from Riobamba

Introducción: la toxoplasmosis adquirida durante por la mujer en edad fértil es un problema aun sin comprender por la comunidad y decisores de los sistemas de salud. En Ecuador existen datos pocos consistentes de la circulación de esta parasitosis, por lo que, ampliar el conocimiento sobre las variables que favorecen su adquisición es de gran interés. Objetivo: determinar la seroprevalencia de la toxoplasmosis en mujeres jóvenes y su relación con variables epidemiológicas. Métodos: Se ensayaron 403 muestras de sueros de estudiantes de la Facultad de Ciencias de la Salud de la Universidad Nacional de Chimborazo, se evaluó el comportamiento serológico de Toxoplasma gondii mediante la determinación de IgG anti Toxoplasma gondii utilizando un método inmunoenzimática, se determinó su relación con hábitos alimentarios, convivencia con animales y conocimiento del riesgo de ser seronegativas al momento de decidir de tener hijos. Resultados: El 26,8 por ciento (108/403) de la muestra resultó seropositivas al Toxoplasma gondii; la vía oral, la forma de adquirir la enfermedad más significativa, se demuestra la relación entre seroprevalencia y convivencia con animales de corral y mascotas. El 73,9 por ciento (298/403) de las encuestadas desconocen que las seronegativas durante el embarazo representan un riesgo potencial. Conclusiones: Se demuestra anticuerpos anti Toxoplasma gondii en sangre de las muestras estudiadas, lo que orienta a infecciones anteriores con Toxoplasma gondii y la influencia de variables estudiadas(AU)

Introduction: Toxoplasmosis acquired by women of childbearing age is a problem still not understood by the community and decision makers from health systems. Few consistent data are available in Ecuador about the circulation of this parasitic infection. Therefore, it is of great interest to broaden knowledge about the variables leading to its acquisition. Objective: Determine the seroprevalence of toxoplasmosis among young women and its relationship to epidemiological variables. Methods: A study was conducted of 403 serum samples from students attending the School of Health Sciences of the National University of Chimborazo. Serological behavior of Toxoplasma gondii was evaluated by determination of anti-Toxoplasma gondii IgG using an enzyme immunoassay. Identification was made of its relationship to eating habits, keeping animals at home, and knowledge about the risk of being seronegative when deciding to have children. Results: Of the total sample, 26.8 percent (108/403) were seropositive for Toxoplasma gondii. The oral route was the most significant mode of acquisition of the disease. A relationship was found between seroprevalence and keeping yard animals and pets. 73.9 percent (298/403) of the respondents were not aware that seronegative results during pregnancy constitute a potential risk. Conclusions: Anti-Toxoplasma gondii antibodies were found in blood of the samples studied, pointing to the existence of previous Toxoplasma gondii infections and the influence of the variables analyzed(AU)

Measles, rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in São Paulo City, Brazil

ABSTRACT Introduction: Vaccines are well-established public health interventions with major impacton the prevalence of infectious diseases, but outbreaks are occurring frequently due to pri-mary and secondary failures, despite high coverage. Surveillance of efficacy and duration ofinduced immunity is a difficult task as it requires invasive blood sampling in children andteenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacyand toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella,and T. gondii in saliva samples of vaccinated young people. Methods: Saliva was collected from 249 public schools students from São Paulo, Brazil, aged7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus proteinA solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired salivaand serum (47) were tested from young adults with serum evidence of T. gondii infectionand from negative children less than 12 month old for standardization. Reproducibility wasgreater than 98% and sensitivity and specificity of the saliva assays were greater than 95%,as well as the concordance of paired saliva and serum samples. Results: Saliva from high school students showed a prevalence of 8.5% (95% CI: 5.0-11.9%)for anti T. gondii IgG; 96.8% (94.6-99%) of anti-measles IgG; 59.1% (53-65%) of anti-rubella IgG,and 57.5% (51.3-63.6%) of anti-mumps IgG. Discussion: The prevalence of antibodies against mumps and rubella after 6-8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemio- logical studies.

Prevalencia de anticuerpos anti-Toxoplasma gondii en embarazadas en siete hospitales de Buenos Aires: Comparación entre 2006 y 2017 / Prevalence of anti-Toxoplasma gondii antibodies in pregnant women in seven hospitals in Buenos Aires area. Comparison 2006 vs. 2017

Se analizó; de forma retrospectiva la presencia de anticuerpos só;©ricos IgG e IgM anti-Toxoplasma gondii en las embarazadas que concurrieron a siete hospitales del ó;rea Metropolitana de Buenos Aires durante 2006 y 2017. La prevalencia de infecció;n, medida como presencia de anticuerpos, en 2006 vs. 2017, fue: Hospital Alemán: 22 y 17% (p = 0.004), Hospital Fiorito: 44 y 33% (p < 0.001), Hospital Gandulfo: 30 y 34% (p 0.025), Hospital Grierson: 60 y 44% (p < 0.001), Hospital Rivadavia: 59 y 51% (p=0.003), Maternidad Sardá 47 y 39% (p < 0.001) y Hospital Thompson: 61 y 51% (p < 0.001). La comparació;n demostró; una disminució;n estadísticamente significativa de la seroprevalencia en seis hos pitales. Tambín disminuyeron significativamente la reactividad para IgM en 2017 respecto de 2006 y la seroprevalencia para T. gondii en el total de la població;n de embarazadas estudiadas, lo que significa un mayor nó;ºmero de mujeres susceptible de desarrollar infecció;n aguda durante el embarazo.

We analyzed the presence of IgG and IgM anti- Toxoplasma gondii, as a measure of infection, in pregnant women attending seven hospitals in the Metropolitan Area of Buenos Aires during 2006 and 2017. T. gondii seroprevalence in 2006 vs. 2017, was: Hospital Alemán: 22 and 17% (p = 0.004), Hospital Fiorito: 44 and 33% (p < 0.001), Hospital Gandulfo: 30 and 34% (p 0.025), Hospital Grierson 60 and 44% (p < 0.001), Hospital Rivadavia: 59 and 51% (p = 0.003), Hospital Sardá: 47 and 39% (p < 0. 001), and Hospital Thompson: 61 and 51% (p < 0.001). The comparison showed a significant decrease in seroprevalence in six hospitals. We also observed a significant decrease in the reactivity for IgM in 2017 compared to 2006 and in the seroprevalence for T. gondii in the overall population of pregnant women in the study. This means that a greater number of women are susceptible to develop acute infection during pregnancy.

Perfil antigénico en fase aguda y crónica de toxoplasmosis en embarazadas por la técnica de Western Blot / Antigenic profile in the acute and chronic phase of toxoplasmosis in pregnant women using the Western Blot technique

La toxoplasmosis es una enfermedad endémica con prevalencia mundial variable, cuyo agente causal es el parásito Toxoplasma gondii. Para un diagnóstico certero de la infección por T. gondii son necesarias combinaciones de métodos serológicos. Estudios recientes han reportado que la técnica de Western Blot permite evidenciar proteínas antigénicas como marcadores de la infección, así como ciertos perfiles proteicos como posibles indicadores de las fases de la infección, aguda y crónica. El objetivo del estudio fue identificar el perfil antigénico específico asociado a las diferentes fases de la toxoplasmosis. Fueron incluidos en el estudio 55 sueros de embarazadas con toxoplasmosis, diferenciados en fase aguda y crónica de la enfermedad por medio del método de ELISA de Avidez de IgG. Mediante el método de Western Blot se observó que las proteínas antigénicas p35, p43, p45, p56 y p107 fueron reconocidas por el 20- 60% de los sueros de pacientes en fase aguda, mientras que p65, p95, p98 y p113 fueron reconocidas por el 17-35% de sueros de pacientes en fase crónica. Se observó que seis proteínas antigénicas, p32, p38, p41, p48, p59 y p72, fueron reconocidas por más del 60% de los sueros de pacientes tanto en fase aguda como crónica. Los resultados obtenidos sugieren que estas seis proteínas podrían ser consideradas como marcadores diagnósticos de la enfermedad(AU)

Toxoplasmosis is an endemic disease with variable global prevalence, being the causative agent the parasite Toxoplasma gondii. For an accurate diagnosis of a T. gondii infection, combinations of serological methods are required. Recent studies have reported that the Western Blot technique allows the detection of antigenic proteins as markers of infection, as well as certain protein profiles as possible indicators of acute and chronic phases of infection. The objective of the study was to identify the specific antigenic profile associated with different phases of toxoplasmosis. Fifty five sera from pregnant women with toxoplasmosis were included in the study, differentiated in acute and chronic phase of the disease by an IgG Avidity ELISA. By using the Western Blot method it was observed that antigenic proteins p35, p43, p45, p56 and p107 were recognized by 20-60% of sera from patients in acute phase, while p65, p95, p98 and p113 were recognized by 17-35% of sera from patients in chronic phase. It was observed that six antigenic proteins, p32, p38, p41, p48, p59 and p72, were recognized by more than 60% of sera from patients in both acute and chronic phases. The results obtained in this study suggest that these six proteins could be considered as diagnostic markers of the disease(AU)

Toxoplasma gondii molecular and immunological identification and risk factors associated with infection in chicken slaughtered at Triângulo Mineiro region, Minas Gerais, Brazil / Identificação molecular e imunológica de Toxoplasma gondii e fatores de risco associados com infecção em galinhas abatidas na região do Triângulo Mineiro, Minas Gerais, Brasil

This study aimed to determine the occurrence of anti-Toxoplasma gondii antibodies in the serum of slaughtered chickens in the region of Triângulo Mineiro, Minas Gerais, Brazil, to detect the parasite in tissues (heart and brain) of serologically positive chickens, based on molecular analysis, and to investigate risk variables associated with the infection. Sera from 417 chickens raised in extensive, semi-intensive, and intensive production systems were tested by an indirect immunofluorescent antibody test (IFAT) and indirect hemagglutination antibody test (IHA). Polymerase chain reaction (PCR) was performed to detect T. gondii DNA in brain and heart tissues. Antibody anti-T. gondii were found in 37.65% (157/417) of chickens by IFAT, and in 75.06% (313/417) by IHA. The Kappa index showed a weak concordance between the techniques (0.087). Association was observed between seropositivity and the variables, age (p < 0.0001), type of feeding (p < 0.0001) and collective raising with other animal's species (p < 0.0001). Association, based on IFAT, was not observed between seropositivity and the variables, sex (p = 0.0526), presence of cats (p > 0.9999), and presence of rats (p > 0.9999). Presence of parasite DNA was detected in brain samples from two chickens, which were raised in intensive and semi-intensive production systems. The results suggest the meat of these slaughtered animals may serve as a transmission source of this protozoan to humans.(AU)

O objetivo do presente estudo foi determinar a frequência de anticorpos anti-Toxoplasma gondii em soro de galinhas abatidas na região do Triângulo Mineiro, Minas Gerais, detectar molecularmente o parasito em tecidos (coração e cérebro) de algumas das aves sorologicamente positivas e averiguar variáveis de risco associadas à infecção. Foram testados soros de 417 galinhas, criadas nos sistemas extensivo, semi-intensivo e intensivo. Para a pesquisa de anticorpos anti-T. gondii foi utilizada a Reação de Imunofluorescência Indireta (RIFI) e Hemaglutinação Indireta (HAI). A Reação em Cadeia da Polimerase (PCR) foi utilizada para detectar o DNA de T. gondii em fragmentos de cérebro e coração. Anticorpos foram detectados no soro de 37,65% (157/417) das aves pela RIFI e em 75,06% (313/417) pela HAI. O índice Kappa mostrou uma fraca concordância entre as técnicas (0,087). Baseado na RIFI, foi verificada associação estatisticamente significativa (p < 0,0001) entre a soropositividade e as variáveis: idade, tipo de alimentação e criação em conjunto com outras espécies animais. Não foi observada associação estatística (p > 0,01) entre as variáveis: sexo, presença de gatos e presença de ratos. Pelo diagnóstico molecular DNA do parasito foi detectado em duas amostras de cérebro, de indivíduos diferentes criados em sistema intensivo e semi-intensivo. Os resultados indicam a possibilidade de a carne dessas aves poderem atuar como fonte de infecção deste protozoário para o homem.(AU)

Preliminary multiplex microarray IgG immunoassay for the diagnosis of toxoplasmosis and rubella

BACKGROUND During pregnancy, toxoplasmosis and rubella can cause serious damage to the mother and the foetus through vertical transmission. Early diagnosis enables implementation of health measures aimed at preventing vertical transmission and minimising damage caused by these diseases. OBJECTIVE Here, we report the development of a multiplex assay for simultaneous detection of IgG antibodies produced during toxoplasmosis and rubella infection. METHODS This assay is based on xMap technology. Initially, by singleplex assays, we evaluated the following antigens: one Toxoplasma gondii lysate; two antigenic extracts of T. gondii (TOX8131 and TOX8122); fragments of T. gondii antigens [SAG-1 (amino acids 45-198), GRA-7 (24-100), GRA-1 (57-149), ROP-4, and MIC-3 (234-306)]; two chimeric antigens composed of fragments of SAG-1, GRA-7, and P35 (CTOX and CTOXH); and fragments of Rubella virus antigens [E-1 (157-176, 213-239, 374-390), E-2 (31-105), and C (1-123)]. FINDINGS A multiplex assay to simultaneously diagnose toxoplasmosis and rubella was designed with the best-performing antigens in singleplex and multiplex assays, which included CTOXH, T. gondii lysate, TOX8131, E-1, and E-2. The multiplex assay showed 100% sensitivity and specificity for anti-T. gondii IgG detection and 95.6% sensitivity and 100% specificity for anti-R. virus IgG detection. MAIN CONCLUSIONS We found that, despite the difficulties related to developing multiplex systems, different types of antigens (extracts and recombinant proteins) can be used to develop high-performance diagnostic tests. The assay developed is suitable to screen for prior T. gondii and R. virus infections, because it is a rapid, high-throughput, low-cost alternative to the current standard diagnostic tools, which require multiple individual tests.

Evaluation of a recombinant rhoptry protein 2 enzyme-linked immunoassay for the diagnosis of toxoplasmosis acquired during pregnancy

The aim of this study was to evaluate an enzyme-linked immunoassay with recombinant rhoptry protein 2 (ELISA-rROP2) for its ability to detectToxoplasma gondii ROP2-specific IgG in samples from pregnant women. The study included 236 samples that were divided into groups according to serological screening profiles for toxoplasmosis: unexposed (n = 65), probable acute infection (n = 48), possible acute infection (n = 58) and exposed to the parasite (n = 65). When an indirect immunofluorescence assay forT. gondii-specific IgG was considered as a reference test, the ELISA-rROP2 had a sensitivity of 61.8%, specificity of 62.8%, predictive positive value of 76.6% and predictive negative value of 45.4% (p = 0.0002). The ELISA-rROP2 reacted with 62.5% of the samples from pregnant women with probable acute infection and 40% of the samples from pregnant women with previous exposure (p = 0.0180). Seropositivity was observed in 50/57 (87.7%) pregnant women with possible infection. The results underscored that T. gondii rROP2 is recognised by specific IgG antibodies in both the acute and chronic phases of toxoplasmosis acquired during pregnancy. However, the sensitivity of the ELISA-rROP2 was higher in the pregnant women with probable and possible acute infections and IgM reactivity.

Chronic Toxoplasmosis Modulates the Induction of Contact Hypersensitivity by TNCB in Mouse Model

Mouse models of chronic toxoplasmosis and atopic dermatitis (AD) were combined to clarify the effect of opportunistic Toxoplasma gondii infection on the development of AD. AD was induced as a chronic contact hypersensitivity (CHS) with repeated challenge of 2,4,6-trinitro-1-chlorobenzene (TNCB) on the dorsal skin of mice. TNCB induced skin thickness increases in both normal and toxoplasmic mice. The changing patterns were different from the sigmoidal which saturated at 20 days in normal mice to the convex saturated at 12 days in toxoplasmic mice with the crossing at 18 days. Compared to normal mice, toxoplasmic mice presented CHS more severely in earlier times and then moderately in later times. These data suggest that host immune modification by T. gondii infection enhances CHS in early times of atopic stimulation but soothes the reaction of CHS in later times in mouse model.

Detection of antibodies to Toxoplasma gondii in wild animals in Brazil

Background Toxoplasmosis is a worldwide zoonosis caused by an obligate intracellular protozoan parasite,Toxoplasma gondii, that affects all warm-blooded animals, including wild animals. The increased number of cases of parasitic infections is mainly due to the destruction of environmental conservation areas, which is driving wild animals out of their habitats and towards urban areas. In this study, the occurrence of T. gondii infection was investigated by the modified agglutination test (MAT) in 26 different species of run over and injured wild animals that were treated at a Brazilian university veterinary hospital, from June 2007 to August 2008.Findings Of the studied animals, six (23.1%; CI95% 11.1-42.2%) had T. gondii antibodies, with titers equal to 10 (4; 66.7%) and 40 (2; 33.3%). The species Pseudalopex vetulus,Cerdocyon thous, Hydrochoerus hydrochaeris and Tapyrus terrestris had titers of 10, while Alouatta caraya and Puma concolor had titers of 40. There was no significant association regarding age, gender or purpose of care (p> 0.05).Conclusions Carnivorous, herbivorous and omnivorous wild animals are potential sentinels of human toxoplasmosis, especially when wild felids are present, maintaining the environmental contamination.(AU)

Toxoplasmose e Toxoplasma gondii / Toxoplasmosis and Toxoplasma gondii

A infecção por Toxoplasma gondii é hoje muito disseminada ao redor do mundo, especialmente no Brasil. A coletânea parte da história da descoberta desse parasita e da doença por ele causada, a toxoplasmose, e visita os diferentes aspectos relacionados ao tema. São apresentados o ciclo evolutivo, a epidemiologia, o diagnóstico, o quadro clínico e o tratamento, em uma ampla revisão sobre o assunto, provavelmente a mais completa já realizada. Somente nos anos 1970 desvendou-se o ciclo de vida desse protozoário, do qual o gato é hospedeiro definitivo. Outros animais de sangue quente, entre eles o ser humano, são hospedeiros intermediários. Muitos indivíduos infectados pelo T. gondii não apresentam sintomas, mas, quando a doença se manifesta, pode ter diferentes configurações, afetando gânglios, olhos, coração, pulmões, fígado, cérebro e meninges, ou articulações. Além de uma completa revisão, a obra também traz para o leitor o que há de mais atual no conhecimento científico acerca da toxoplasmose e do T. gondii. O livro cobre praticamente todos os campos do conhecimento sobre o agente etiológico e a doença, apresentando novos aspectos, particularmente em relação à bioquímica, à interação entre o parasita e a célula hospedeira e à resposta imunológica à infecção.

Gestational toxoplasmosis in Paraná State, Brazil: prevalence of IgG antibodies and associated risk factors

The aim of the present study was to verify the association between seropositivity for IgG anti-Toxoplasma gondii antibodies and social, economic and environmental variables of pregnant women attending the public health centers of Paraná, Brazil. From January 2007 to July 2010, 2226 pregnant women were interviewed and detection of anti-T. gondii specific IgG and IgM antibodies was performed by chemiluminescence test. Seropositivity for anti-T. gondii IgG was observed in 1151 (51.7%) pregnant women, 29 of which (1.3%) presented IgM reagent with IgG of high avidity. The variables associated with the presence of IgG were residency in the rural area, more than one pregnancy, less than or equal to eight years schooling, low per capita income, age group, raw or poorly cooked meat ingestion, and contact with the soil. There was neither association with raw fruit and vegetable ingestion nor with the presence of cats in the residencies.

Soroprevalência de toxoplasmose na região do Pontal do Triângulo Mineiro, Minas Gerais, Brasil / The prevalence of toxoplasmosis in the Pontal of the Triângulo Mineiro region, Minas Gerais State, Brazil

Toxoplasma gondii é um parasito intracelular obrigatório de distribuição mundial com diferentes formas infectantes: taquizoítos, bradizoítos e oocistos. A toxoplasmose é uma zoonose comum em vertebrados, sendo os felídeos seus hospedeiros definitivos. Possui elevada prevalência sorológica,é assintomática em indivíduos imunocompetentes e detectada mediante anticorpos IgM e IgGcontra antígenos do parasito. Neste estudo, investigou-se a soroprevalência de toxoplasmose no Pontal do Triângulo Mineiro, Minas Gerais, em 1.532 pacientes atendidos em um laboratório de análises clínicas do município de Ituiutaba no período de agosto 2007 a abril 2010, mediante a detecção de anticorpos IgM e IgG anti-T. gondii. Foram obtidas informações sobre gênero e idade por meio de estudo retrospectivo dos exames destes pacientes. Os testes sorológicos empregados foram hemaglutinação passiva e imunofluorescência indireta. Não houve a detecção de IgM anti-T.gondii e 36por cento dos indivíduos eram IgG anti-Toxoplasma gondii sororreagentes, o que pode indicarque os pacientes estavam na fase crônica da doença. Neste trabalho, observou-se que a prevalência foi maior em indivíduos de 16 a 45 anos, com títulos de IgG de 1:256. Sugere-se, portanto, a implementação de medidas preventivas na região do Pontal do Triângulo Mineiro, Minas Gerais.

Toxoplasma gondii antibody profile in HIV-1-infected and uninfected pregnant women and the impact on congenital toxoplasmosis diagnosis in Rio de Janeiro, Brazil

OBJECTIVE: Compare the anti-T. gondii IgG titer between HIV-1 infected and non HIV-1 infected pregnant women and report three cases of congenital toxoplasmosis resulting from reactivation of infection during pregnancy of HIV-1 infected women. METHODS: This study was conducted among 2,270 pregnant women with chronic Toxoplasma gondii infection (absence of IgM and presence of IgG), including 82 HIV-1 infected and 2,188 non-infected women. RESULTS: The average anti-T. gondii IgG titer was 127 for the 2,188 non-HIV-1 infected women, and 227 for the 82 HIV-1-infected women (p = 0,007). These results suggested that higher anti-T. gondii IgG titers in HIV-1-infected pregnant women may not be indicative of an elevated risk for fetal infection. In this study three cases of congenital toxoplasmosis that resulted from infection reactivation during pregnancy of HIV-1-infected women were manifested by fetal death, symptomatic infection, and infant without symptoms, respectively. In two of these women, a ten-fold increase in IgG levels above used cutoff was observed (2,320 UI/mL and 3,613 UI/mL, respectively). In the third pregnant women anti-T. gondii IgG titers during pregnancy did not rise despite the occurrence of congenital toxoplasmosis (204; 198; 172 UI/mL). CONCLUSIONS: Congenital toxoplasmosis resulting reactivation of infection during pregnancy in the studied group leads us to believe that it is a public health problem, especially in our population, in which seroprevalence of T. gondii infections is high. These findings also suggest that special attention is necessary during pregnancy, because the serologic diagnosis may not be indicative of toxoplasmosis reactivation.

Depletion of CD25+ cells during acute toxoplasmosis does not significantly increase mortality in Swiss OF1 mice

The interleukin (IL)-2R alpha chain (CD25) is expressed on regulatory T cells (Treg), which constitute more than 85 percent of the CD25+ T cell population in a naïve mouse. CD25 is also expressed on effector T cells in mice suffering from an acute infection by the obligate intracellular protozoan parasite, Toxoplasma gondii. Lethal toxoplasmosis is accompanied by a significant loss of Treg in mice naturally susceptible to toxoplasmosis. The present study was done to explore the role of Treg cells using an anti-CD25 antibody-mediated depletion in mice naturally resistant to toxoplasmosis. Although a significant decrease in the percentage of Treg cells was observed following anti-CD25 monoclonal antibody injections, the depletion of CD25+ cells during acute toxoplasmosis did not significantly increase the mortality of Swiss OF1 mice and no significant difference was observed in the brain parasitic load between the mice in the depleted-infected and isotype-infected groups. We found no significant difference between the titres of total IgG in the sera of the mice from the two groups in the chronic phase. However, CD25+ cells depletion was followed by significantly higher levels of IL-12 in the serum of depleted mice than in that of mice injected with the isotype control antibody.

Evaluación de un test comercial de avidez de IgG: Aporte al diagnóstico de primoinfección por Toxoplasma gondii / Evaluation of an IgG avidity commercial test: Contribution to diagnosis of primary infection caused by Toxoplasma gondii

Introduction: Toxoplasmosis (T) is a major chronic parasitic infection in immunocompromised patients and pregnant women. It is important to discriminate between acute phase (AT) and chronic phase (CT). Diagnosis is serological in immunocompetent patients (concentration of IgG and IgM). Objective: To evaluate the utility of an IgG avidity test (A-IgG) to identify the acute and chronic stage. Avidity is the strength of affinity between a specific immunoglobulin and the protein antigenic epitope of the infecting agent, an affinity that increases over time. Patients and Methods: We used a qualitative kit that measures the avidity of IgG, discriminating the two phases. In 35 patients with clinical diagnosis of AT and/or CT, IgG, IgM and IgG A (VIDAS®) were performed. Results: Patients with AT were positive for IgM and IgG, but presented weak avidity. In the 21 cases with CT, 52 percent (n: 11) were IgM positive and 100 percent (n: 21) had positive IgG with strong avidity. Discussion: The results confirm that the test of A-IgG may be useful in the diagnosis of AT, and has 100 percent concordance with reference test (qualitative IgM + quantitative IgG). The result is available within 24 hrs, and may be useful in diagnosis of AT in pregnant women.

Introducción: Toxoplasmosis (T) es una infección parasitaria crónica importante en pacientes inmunocompro-metidos y mujeres embarazadas. Es relevante discriminar entre fase aguda (TA) y fase crónica (TC). Su diagnóstico es serológico en inmunocompetentes (detección de IgG e IgM). Objetivo: Evaluar la utilidad del test de avidez IgG (A-IgG) para identificar la fase aguda y o crónica. Avidez es la fuerza de afinidad entre una inmunoglobulina específica y el epítope de la proteína antigénica del agente infectante, afinidad que aumenta con el tiempo. Pacientes y Métodos: Se usó un test cualitativo que mide la avidez de IgG, discriminando las dos fases. A 35 pacientes con diagnóstico clínico de TA y o TC, se les realizó IgG, IgM e A-IgG en Equipo VIDAS®. Resultados: Los pacientes con TA fueron positivos para IgM e IgG y presentaron avidez débil. Los 21 casos con TC 52 por ciento (n: 11) tuvieron IgM positivo y 100 por ciento (n: 21) tuvo IgG positiva con avidez fuerte. Discusión: Los resultados confirman que el test de A-IgG puede ser de gran utilidad en el diagnóstico de TA, concordancia: 100 por ciento con test de referencia (IgM cualitativa + IgG cuantitativa). El resultado está disponible en menos de 24 hrs, pudiendo ser útil en el diagnóstico de TA en mujeres embarazadas.

Serological monitoring of a Toxoplasma infection after hematopoietic stem cell transplantation / Monitoramento sorológico de uma infecção toxoplásmica após transplante de células progenitoras hematopoiéticas

We report a primary response to Toxoplasma gondii following a hematopoietic stem cell transplantation in a patient with multiple myeloma. The primary response to T. gondii was supported by IgM, IgG and IgA seroconversion. The patient was promptly treated and there were no complications related to toxoplasmosis in the subsequent months.

Esse relato de caso descreve uma resposta primária ao Toxoplasma gondii após transplante de células progenitoras hematopoiéticas em paciente com mieloma múltiplo. A resposta primária para o T. gondii foi evidenciada pela soroconversão observada na resposta de anticorpos IgM, IgG e IgA. O paciente foi prontamente tratado e complicações relacionadas à toxoplasmose não foram observadas nos meses subseqüentes.

Avaliação comparativa entre o desempenho dos reagentes paratoxoplasmose AxSYM, VIDAS e VIDIA em um país latinoamericano com alta soroprevalência / Comparative evaluation of AxSYM, VIDAS and VIDIA toxoplasmosis reagent performance in a high seroprevalence Latin American country

Aims: The purpose of this study was to compare the performance of three automated immunoassays for the detection of IgM and IgG Toxoplasma gondii antibodies using sera of pregnant women living in Colombia, a Latin American country with a high seroprevalence. Methods: A total of 905 sera were tested for IgM antibodies and 914 for IgG antibodies with AxSYM, VIDAS and VIDIA immunoassays. Discrepancies were resolved by using the dye test for IgG antibodies, and the ISAGA test for IgM. Results: The overall agreement between AxSYM, VIDAS and VIDIA assays was excellent for detection of IgG and IgM antibodies, and discrepancies were relatively rare (3.6% and 5.5% of sera for IgG and IgM antibodies, respectively). The performance of the three immunoassays was similar for the detection of IgG antibodies with high sensitivity (100.00% for VIDIA, 99.59% for VIDAS, 99.38% for AxSYM) and specificity (99.04% for VIDIA, 98.82% for AxSYM, 98.57% for VIDAS). The specificity for IgM antibodies was excellent for the three immunassays (99.88% for VIDIA, 99.76% for AxSYM and VIDAS). The sensitivity of the detection of IgM antibodies was higher with VIDIA (95.12%) than with VIDAS (76.74%) and AxSYM (61.90%) assays. The correlation between IgG titers was limited between AxSYM and VIDAS assays and between AxSYM and VIDIA assays, but was excellent between VIDIA and VIDAS assays. Conclusions: Our study performed with Latin American sera confirmed the excellent specificity of AxSYM, VIDAS and VIDIA assays for the detection of IgG and IgM antibodies already reported in other countries. The sensitivity of the detection of IgG antibodies was slightly higher with VIDIA than with VIDAS and AxSYM assays. The sensitivity of the detection of IgM antibodies was higher with VIDIA than with VIDAS and AxSYM assays.

Humoral and cellular immune responses as diagnostic tools in human toxoplasmosis

The study was conducted to assess the humoral and cellular immune responses in patients suspected to have Toxoplasma infection, and to evaluate their use as diagnostic tools. Seventy six persons were enrolled in the study, 56 of them are patients with toxoplasmosis. In addition to 20 apparently healthy persons were served as control. They were divided into 4 main groups according to their signs and symptoms, Group I, 17 patients with ocular signs and symptoms suggestive of toxoplasmosis Group II, 23 patients complaining of complicated obstetric problems, Group III, 9 infants and children with signs and symptoms of congenital toxoplasmosis, and Group IV, 7 patients with manifestations suggesting toxoplasmic lymphadenopathy. RH Toxoplasma strain was used. Experimental animals: 400 mice were used, 10 each time, for maintainance of Toxoplasma strain, by regular serial passage and for preparation of antigen. Enzyme linked immunosorbent assay [ELISA] for detection of anti Toxoplasma IgG and IgM antibodies. Lymphocyte transformation test were done for detection of specific lymphocyte proliferation [blastogenic response]. Out of total 56 patients, 49 patients [87.5%] gave positive results to Toxopasma antigen in one or more of the specific techniques applied. Seven patients gave negative results were recommended for periodic follow up before exclusion of toxoplasmosis. High rates of seropositivity detected among suspected patients suggest the reliability of ELISA in diagnosis of toxoplasmosis. Specific lymphoblastognic response would confirm the results and reveal dormant infection in some suspected subjects. However, rising titre/ seroconversion is a prerequisite for therapy