Autoantibodies Against Ubiquitous and Confined Antigens in Patients With Ocular, Neuro-Ophthalmic and Congenital Cerebral Toxoplasmosis.

Toxoplasma gondii infection can trigger autoreactivity by different mechanisms. In the case of ocular toxoplasmosis, disruption of the blood-retinal barrier may cause exposure of confined retinal antigens such as recoverin. Besides, cross-reactivity can be induced by molecular mimicry of parasite antigens like HSP70, which shares 76% identity with the human ortholog. Autoreactivity can be a determining factor of clinical manifestations in the eye and in the central nervous system. We performed a prospective observational study to determine the presence of autoantibodies against recoverin and HSP70 by indirect ELISA in the serum of 65 patients with ocular, neuro-ophthalmic and congenital cerebral toxoplasmosis. We found systemic autoantibodies against recoverin and HSP70 in 33.8% and 15.6% of individuals, respectively. The presence of autoantibodies in cases of OT may be related to the severity of clinical manifestations, while in cases with CNS involvement they may have a protective role. Unexpectedly, anti-recoverin antibodies were found in patients with cerebral involvement, without ocular toxoplasmosis; therefore, we analyzed and proved cross-reactivity between recoverin and a brain antigen, hippocalcin, so the immunological phenomenon occurring in one immune-privileged organ (e.g. the central nervous system) could affect the environment of another (egg. the eye).

A Proinflammatory Immune Response Might Determine Toxoplasma gondii Vertical Transmission and Severity of Clinical Features in Congenitally Infected Newborns.

Toxoplasma gondii is the etiological agent of toxoplasmosis. Mother-to-child transmission of this parasite can occur during pregnancy. Newborns with congenital toxoplasmosis may develop central nervous system impairment, with severity ranging from subclinical manifestations to death. A proinflammatory/regulated specific immune profile is crucial in the defense against the parasite; nevertheless, its role in the infected pregnant women and the congenitally infected offspring has been poorly explored, and there is still no consensus about its relation to parasite vertical transmission or to severity and dissemination in the congenitally infected newborns. This work aimed to characterize these relations by means of principal component and principal factor analyses. For this purpose, we determined the specific production of the four immunoglobulin G antibody subclasses, cytokines, and lymphocyte proliferation in the T. gondii-infected pregnant women-10 who transmitted the infection to their offspring and seven who did not-as well as in 11 newborns congenitally infected and grouped according to disease severity (five mild and six moderate/severe) and dissemination (four local and seven disseminated). We found that the immune response of nontransmitter women differed from that of the transmitters, the latter having a stronger proinflammatory response, supporting a previous report. We also found that newborns who developed moderate/severe disease presented higher levels of lymphocyte proliferation, particularly of CD8+ and CD19+ cells, a high proportion of tumor necrosis factor α producers, and reduced expression of the immune modulator transforming growth factor ß, as opposed to children who developed mild clinical complications. Our results suggest that a distinctive, not regulated, proinflammatory immune response might favor T. gondii vertical transmission and the development of severe clinical manifestations in congenitally infected newborns.

Testing New Peptides From Toxoplasma gondii SAG1, GRA6, and GRA7 for Serotyping: Better Definition Using GRA6 in Mother/Newborns Pairs With Risk of Congenital Transmission in Mexico.

Toxoplasma gondii variant influences clinical profile in human congenital and ocular toxoplasmosis. Parasite genotyping represents a challenge due to insufficient amount of genetic material of the protozoan in the host samples, and isolates are hard to obtain, especially from pediatric patients. An alternative is serotyping, which is based on the presence of specific antibodies against polymorphic proteins related to virulence; the more widely used are GRA6 and GRA7, but most works report cross reactions among the classical strains (I, II, and III). We designed new peptides of GRA6, GRA7, and SAG1 proteins, with more SNPs among the three clonal strains than those previously designed. This was done by identifying BcR and polymorphic epitopes by means of bioinformatics; then we designed peptides with linkers joining the specific regions and predicted their 3D structure. With the commercial molecules synthesized on the basis of these designs, we tested 86 serum samples from 42 mother/newborn pairs and two congenitally infected newborns, by indirect ELISA. We implemented a strategy to determine the serotype based on scatter plots and a mathematical formula, using ratios among reactivity indexes to peptides. We found low frequency of samples reactive to GRA7 and SAG1, and cross reactions between GRA6 serotypes I and III; we modified these later peptides and largely improved distinction among the three clonal strains. The chronicity of the infection negatively affected the reactivity index against the peptides. Serotyping both members of the mother/child pair improves the test, i.e., among 26% of them only one member was positive. Serotype I was the most frequent (38%), which was congruent with previous genotyping results in animals and humans of the same area. This serotype was significantly more frequent among mothers who transmitted the infection to their offspring than among those who did not (53 vs. 8%, p = 0.04) and related to disease dissemination in congenitally infected children, although non-significantly. In conclusion, serotyping using the improved GRA6 peptide triad is useful to serotype T. gondii in humans and could be implemented for clinical management and epidemiological studies, to provide information on the parasite type in specific areas.

Report of an unsual case of anophthalmia and craniofacial cleft in a newborn with Toxoplasma gondii congenital infection.

BACKGROUND: We present one unusual case of anophthalmia and craniofacial cleft, probably due to congenital toxoplasmosis only. CASE PRESENTATION: A two-month-old male had a twin in utero who disappeared between the 7th and the 14th week of gestation. At birth, the baby presented anophthalmia and craniofacial cleft, and no sign compatible with genetic or exposition/deficiency problems, like the Wolf-Hirschhorn syndrome or maternal vitamin A deficiency. Congenital toxoplasmosis was confirmed by the presence of IgM abs and IgG neo-antibodies in western blot, as well as by real time PCR in blood. CMV infection was also discarded by PCR and IgM negative results. Structures suggestive of T. gondii pseudocysts were observed in a biopsy taken during the first functional/esthetic surgery. CONCLUSIONS: We conclude that this is a rare case of anophthalmia combined with craniofacial cleft due to congenital toxoplasmosis, that must be considered by physicians. This has not been reported before.

Vertical transmission and fetal damage in animal models of congenital toxoplasmosis: A systematic review.

In humans, the probability of congenital infection and fetal damage due to Toxoplasma gondii is dependent on the gestation period at which primary infection occurs. Many animal models have been used for vaccine, drug testing, or studies on host or parasite factors that affect transmission or fetal pathology, but few works have directly tested fetal infection and damage rates along gestation. So, the purpose of this work was to perform a systematic review of the literature to determine if there is a model which reflects these changes as they occur in humans. We looked for papers appearing between 1970 and 2014 in major databases like Medline and Scopus, as well as gray literature. From almost 11,000 citations obtained, only 49 papers fulfilled the criteria of having data of all independent variables and at least one dependent datum for control (untreated) groups. Some interesting findings could be extracted. For example, pigs seem resistant and sheep susceptible to congenital infection. Also, oocysts cause more congenitally infected offspring than tissue cysts, bradyzoites or tachyzoites. In spite of these interesting findings, very few results on vertical transmission or fetal damage rates were similar to those described for humans and only for one of the gestation thirds, not all. Moreover, in most designs tissue cysts - with unknown number of bradyzoites - were used, so actual dose could not be established. The meta-analysis could not be performed, mainly because of great heterogeneity in experimental conditions. Nevertheless, results gathered suggest that a model could be designed to represent the increase in vertical transmission and decrease in fetal damage found in humans under natural conditions.

Toxoplasma gondii invasion and replication within neonate mouse astrocytes and changes in apoptosis related molecules.

Toxoplasma gondii invades any nucleated cell, but different replication speed and effects on survival/apoptosis processes have been found depending on cell type. There are scarce and controversial results regarding the effect of this parasite on host cell apoptosis within the brain. The invasion and replication of T. gondii RH strain within newborn mouse astrocytes were evaluated in the present work. At 4 hpi>90% cells were infected and harbored one to three parasitophorous vacuoles with one tazchyzoite/vacuole. Cell culture massive destruction started after 24 h of exposure, when the parasite already replicated, with a duplication time of around 5 h. The effect of T. gondii infection on apoptosis was also evaluated by changes in some anti- and pro-apoptotic markers. At early infection times decreased Bcl-2, Survivin and PUMA and increased Noxa expression was found, although Survivin and Noxa mRNA levels reverted towards an anti-apoptotic phenotype after 6 h. Caspases 3/7 activity decreased three hours after infection, although it returned to normal levels thereafter. This enzymatic activity was strongly stimulated by Cisplatin (anti-neoplasic drug) but it was inhibited by previous T. gondii infection. Likewise, parasite invasion prevented PARP-1 fragmentation and cell apoptosis induced by the same drug. In conclusion, astrocytes seem to activate some apoptosis signals shortly after infection, but the parasite takes control of the cell and inhibits programmed death for up to 24 h, until it replicates, egresses and generates cellular destruction.

Toxoplasma gondii invasion and replication in astrocyte primary cultures and astrocytoma cell lines: systematic review of the literature.

Toxoplasma gondii is a cosmopolitan protozoan which infects all homoeothermic species, including humans. This parasite may cause severe neurological problems in congenitally infected newborns or immunocompromised individuals, but it also provokes psychiatric and neurological disorders as well as behavioural and sensory deficit. There is controversy regarding the effect of T. gondii upon astrocytes, which may serve as parasite proliferation recipients or protective immune response activators within the central nervous system. This apparent contradiction could partially be due to the infection degree obtained in the different experiments reported. Thus, we decided to systematically review the in vitro models used to study these phenomena. Fifteen articles from which direct invasion and replication data could be gathered were found. Very heterogeneous results emerged, mainly due to diversity of models in relation to parasite strain (virulence), host species, parasite dose and evaluation times after infection. Also, the results were measured in diverse ways, i.e. some reported percent infected cells, while others informed parasites pervacuole or cell, or parasitic vacuoles per cell. Very few conclusions could be drawn, among them that human astrocytoma cell lines and mouse astrocytes seem more susceptible to infection and less resistant to tachyzoite proliferation than human primary culture astrocytes. The present study supports the need to reanalyse T. gondii astrocyte invasion and replication processes, especially with the use of actual technology, which allows detailed mechanistic studies.

Short report: limited and short-lasting humoral response in Taenia solium: seropositive households compared with patients with neurocysticercosis.

Epidemiologic data suggest that 30-40% of Taenia solium-seropositive people become spontaneously negative without acquiring cysticercosis. To compare the responses of these individuals with those of patients with neurocysticercosis, we screened seropositive persons among family members of 16 patients. We searched for specific antibodies in patients and their 118 households by an enzyme-linked immunoelectrotransfer blot assay using specific glycoproteins of T. solium metacestodes. We found six seropositive individuals without neurocysticercosis among members of four families. The matching patients were young, harbored viable cysts, and had short evolution of disease. The baseline response of healthy seropositive individuals was scarce and showed a low frequency of antibodies against glycoproteins GP39-42 and GP24, which are immunodominant in patients with neurocysticercosis. Moreover, they became spontaneously negative in few months. The response of patients was heterogeneous as shown in other studies. The results of this work support a highly dynamic host-parasite immunologic interaction and suggest individual susceptibility or level of exposure among family members.

Current consensus guidelines for treatment of neurocysticercosis.

Taenia solium neurocysticercosis is a common cause of epileptic seizures and other neurological morbidity in most developing countries. It is also an increasingly common diagnosis in industrialized countries because of immigration from areas where it is endemic. Its clinical manifestations are highly variable and depend on the number, stage, and size of the lesions and the host's immune response. In part due to this variability, major discrepancies exist in the treatment of neurocysticercosis. A panel of experts in taeniasis/cysticercosis discussed the evidence on treatment of neurocysticercosis for each clinical presentation, and we present the panel's consensus and areas of disagreement. Overall, four general recommendations were made: (i) individualize therapeutic decisions, including whether to use antiparasitic drugs, based on the number, location, and viability of the parasites within the nervous system; (ii) actively manage growing cysticerci either with antiparasitic drugs or surgical excision; (iii) prioritize the management of intracranial hypertension secondary to neurocysticercosis before considering any other form of therapy; and (iv) manage seizures as done for seizures due to other causes of secondary seizures (remote symptomatic seizures) because they are due to an organic focus that has been present for a long time.

Infectious diseases in Mexico. A survey from 1995-2000.

Data obtained at a central laboratory for emerging, re-emerging, and other infectious diseases in Mexico from 1995-2000 are presented. An outstanding increase of DEN-3 circulation was identified. Aedes aegypti, the dengue vector, is widely distributed. Leptospirosis has become the most important differential diagnosis for dengue. Identification of rabies virus variants allowed cataloging of new transmitters of rabies. Rotavirus showed a clear seasonal distribution, while different proportions of pathogenic classes of Escherichia coli under endemic and outbreak conditions were seen. Serotypes of several bacteria are reported as well as the sources of isolation and frequency of Shigella, Salmonella, and Vibrio cholerae. Rise and disappearance of cholera could be followed along the past decade. Influenza strains were identified, as were several pathogens causing sexually transmitted infections. Laboratory support was important for surveillance after Hurricane Mitch. Multidrug-resistant strains of Mycobacterium tuberculosis are emerging and primary resistance is very high. It is now mandatory to search for antibodies to Trypanosoma cruzi in blood banks. Triatoma barberi, a peridomestic bug, is the main vector of Chagas disease. Localized cutaneous leishmaniosis increased in regions having a guerrilla element in Chiapas. Modern immunodiagnostic techniques are used for control studies of cysticercosis and similar techniques were recently standardized for Trichinella spiralis detection. Low iodine values in children's urine were found in several Mexican states; therefore, use of iodized salt should be encouraged.

Evaluation of the enzyme-linked immunoelectrotransfer blot assay for diagnosis of neurocysticercosis in children.

Neurocysticercosis is a common problem in developing countries, and it causes neurologic disorders in children. Immunodiagnosis with Taenia solium glycoproteins as an antigen has been validated in adults but not in children. The aim of this work was to evaluate a Taenia solium glycoproteins-based enzyme-linked immunoelectrotransfer blot assay in children with neurocysticercosis. Twenty-five confirmed cases of neurocysticercosis and 50 healthy children from the same community were included. The test had a sensitivity of 72% and a specificity of 96%. Sensitivity was higher (100%) in cases with multiple cysts and in multiple sites. Sensitivity was higher when cysts were in parenchyma (86%) than when they were in the subarachnoid space. The most frequently recognized proteins were 24, 39 to 42, and 50 kDa. Diagnosis was more efficient in serum than in cerebrospinal fluid. Western blot is a reliable method for serologic diagnosis of neurocysticercosis in children. Multiple cysts and infections in multiple sites elicited a stronger immune response.

Taeniasis and cysticercosis prevalence in a small village from Northeastern Brazil.

UNLABELLED: Although not considered as an endemic region, the Northeast of Brazil has the necessary conditions for the development of taeniasis-cysticercosis complex. In a previous paper, we demonstrated that Mulungu do Morro municipality, in the State of Bahia, has a high seroprevalence to cysticercosis in epileptic patients. OBJECTIVE: to determine the prevalence of taeniasis and positive cysticercosis serology in the population of Mulungu do Morro. METHOD: blood and stool samples were collected from a random sampling of the population, by family. The identification of antibodies against T. solium cysticerci was made by EITB and T. solium antigens were identified using a polyclonal antibody-capture ELISA. RESULTS: the cysticercosis seroprevalence was 1.6% (C.I. = 0.8 to 2.8%) and the taeniasis prevalence 4.5% (C.I. = 3.0 to 6.5%). Seropositivity to cysticercosis was higher among those who lived in a house of a person testing positive for coproantigen, p=0.017. CONCLUSION: our results demonstrate that the taeniasis-cysticercosis complex is endemic in Mulungu do Morro. We believe that all areas in the world with the same socio-economic and sanitary characteristics are likely to have high prevalence of this parasite.

Taeniasis and cysticercosis prevalence in a small village from Northeastern Brazil

Although not considered as an endemic region, the Northeast of Brazil has the necessary conditions for the development of taeniasis-cysticercosis complex. In a previous paper, we demonstrated that Mulungu do Morro municipality, in the State of Bahia, has a high seroprevalence to cysticercosis in epileptic patients. OBJECTIVE: to determine the prevalence of taeniasis and positive cysticercosis serology in the population of Mulungu do Morro. METHOD: blood and stool samples were collected from a random sampling of the population, by family. The identification of antibodies against T. solium cysticerci was made by EITB and T. solium antigens were identified using a polyclonal antibody-capture ELISA. RESULTS: the cysticercosis seroprevalence was 1.6 percent (C.I. = 0.8 to 2.8 percent) and the taeniasis prevalence 4.5 percent (C.I. = 3.0 to 6.5 percent). Seropositivity to cysticercosis was higher among those who lived in a house of a person testing positive for coproantigen, p=0.017. CONCLUSION: our results demonstrate that the taeniasis-cysticercosis complex is endemic in Mulungu do Morro. We believe that all areas in the world with the same socio-economic and sanitary characteristics are likely to have high prevalence of this parasite

Laboratory diagnosis of human neurocysticercosis: double-blind comparison of enzyme-linked immunosorbent assay and electroimmunotransfer blot assay.

Neurocysticercosis is a common disease in underdeveloped countries. Its diagnosis is based on clinical, imaging (tomography or magnetic resonance), epidemiological, and laboratory data. Several methods based on the detection of antibodies against cysticerci in cerebrospinal fluid or serum have been tested. Among them, an enzyme-linked immunosorbent assay (ELISA) based on the use of a crude parasite antigen has been used by the laboratory network of cysticercosis in Mexico, which has given support to clinicians for up to 7 years. A Taenia solium-specific glycoprotein-based electroimmunotransfer blot (EITB) assay was reported to be highly sensitive and specific for this purpose. In order to compare both techniques, we studied 100 neurocysticercosis patients and 70 neurological noncysticercosis controls and searched for specific antibodies in paired samples of serum and cerebrospinal fluid using both techniques. We found that the EITB assay is more sensitive than the ELISA, especially when serum is being tested. Both techniques are more sensitive in cases with multiple living cysts than in cases with single cysts or calcified lesions. No global differences among cases with parasites located in different parts of the central nervous system were found. In the patients with cysts within the parenchyma, the sensitivity of the EITB assay was higher with serum than with cerebrospinal fluid. The immunodominant bands were found to be the same as those previously reported, i.e., GP-39 to -42, GP-24, and GP-13. Based on these results, we suggest the use of the EITB assay in routine diagnosis of cysticercosis for clinical cases.

Cuantificación de linfocitos T CD4+ y de RNA viral en pacientes con VIH/SIDA / Quantification of CD4+ T lymphocytes and viral DNA in patients with HIV/AIDS

Se determinaron los valores de los marcadores de progresión (carga viral y cuenta de linfocitos T CD4+) de 410 pacientes que viven con VIH-SIDA, que estaban en diferentes etapas clínicas de la enfermedad y bajo diferentes esquemas terapéuticos. El objetivo fue determinar la correlación entre los valores de los marcadores de progresión y el estado clínico de los pacientes. Se utilizaron metodologías comerciales para cuantificar las subpoblaciones de linfocitos y el RNA viral circulante. Los resultados indican que existía correlación entre los valores de CD4+ bajos y la carga viral alta en pacientes que estaban bajo tratamiento antirretroviral pero no en pacientes sin tratamiento. Además el análisis de 1208 muestras procesadas durante 1999 mostró que el 46 por ciento de los pacientes tenían menos de 200 linfocitos T CD4+/mL de sangre y más de 500 copias de RNA circulante. Se discuten las implicaciones de estos resultados en la salud pública de México.

Cysticercosis in epileptic patients of Mulungu do Morro Northeastern Brazil

With the aim to study the magnitude of infection by the metacestode of Taenia solium in a population of epileptic patients in the arid region of Bahia, Northeastern Brazil, we examined 200 consecutive cases who attended an ambulatory clinic in the disctrict of Mulungu do Morro. Sixty-six of the patients had a diagnosis of epilepsy. From them 10 (15.2 percent) presented antibodies against a specific fraction of antigens in Western blot, and 4 (6.0 percent) had circulating parasite products, as tested by capture ELISA. Only 1 case was positive for antibodies and antigens. We found that the frequency of seropositivity was related to the time without epileptic seizure. We conclude that cysticercosis is endemic in the region of Mulungu do Morro and that it is related to a benign form of epilepsy

Diagnóstico, tratamiento y mecanismos de evasión inmune de la cisticercosis por larvas de taenia solium en seres humanos y cerdos

En este trabajo se presenta una revisión del ciclo de vida de Taenia solium y un análisis de los principales factores de riesgo involucrados en la adquisición de la cisticercosis. También se presentan los datos obtenidos por nuestro grupo con respecto al diagnóstico inmunológico y la teniasis; sobre la quimioterapia experimental de la cisticercosis porcina y los que sugieren la existencia de mecanismos de evasión inmune ejercidos por los parásitos para sobrevivir en sus hospderos inmunocompetentes