Cinara Cássia Brandão de Mattos

Contribution of laboratory methods in diagnosing clinically suspected ocular toxoplasmosis in Brazilian patients

This prospective study evaluated the value of laboratorial diagnosis in ocular toxoplasmosis analyzing peripheral blood samples from a group of Brazilian patients by immunologic and molecular methods. We analyzed blood samples from 184 immunocompetent patients with ocular disorders divided into 2 groups: Group I, composed of samples from 49 patients with ocular toxoplasmosis diagnosed by clinical features; Group II, samples from 135 patients with other ocular diseases. Samples were assayed by conventional polymerase chain reaction (cnPCR), real-time PCR (qPCR) for Toxoplasma gondii, indirect immunofluorescence reaction (IF), avidity test (crude tachyzoite lysate as antigen), and excreted-secreted tachyzoite proteins as antigen (ESA-ELISA). cnPCR and qPCR profiles were concordant in all samples. Positive PCR was shown in 40.8% of group I patients. The majority of the positive blood samples (75%) were taken from patients with toxoplasmic retinochoroiditis scars, and the others (25%), from patients with retinal exudative lesions. Despite that 86 of the 135 patients from Group II had asymptomatic toxoplasmosis, all DNA blood samples had negative PCR. Concordant results were shown in the data obtained by serologic methods. Around 24% of the patients with ocular toxoplasmosis had high antibody titers determined by ESA-ELISA and IF. Anti-ESA antibodies are shown principally in patients with active infection. Collectively, these data demonstrate the presence of tachyzoites in the blood of patients with chronic infection, supporting the idea of recurrent disease. Circulating parasites in blood of immunocompetent individuals may be associated with the reactivation of the ocular disease.

Cerebral and ocular toxoplasmosis related with IFN-γ, TNF-α, and IL-10 levels.

This study analyzed the synthesis of Interferon gamma (IFN-γ), Tumor Necrosis Factor alpha (TNF-α), and Interleukin 10 (IL-10) in chronically infected patients which developed the symptomatic disease as cerebral or ocular toxoplasmosis. Blood from 61 individuals were divided into four groups: Cerebral toxoplasmosis/AIDS patients (CT/AIDS group) (n = 15), ocular toxoplasmosis patients (OT group) (n = 23), chronic toxoplasmosis individuals (CHR group) (n = 13) and healthy individuals (HI group) (n = 10). OT, CHR, and HI groups were human immunodeficiency virus (HIV) seronegative. The diagnosis was made by laboratorial (PCR and ELISA) and clinical subjects. For cytokine determination, peripheral blood mononuclear cells (PBMC) of each patient were isolated and stimulated in vitro with T. gondii antigen. IFN-γ, TNF-α, and IL-10 activities were determined by ELISA. Patients from CT/AIDS and OT groups had low levels of IFN-γ when were compared with those from CHR group. These data suggest the low resistance to develop ocular lesions by the low ability to produce IFN-γ against the parasite. The same patients, which developed ocular or cerebral toxoplasmosis had higher TNF-α levels than CHR individuals. High TNF-α synthesis contribute to the inflammatory response and damage of the choroid and retina in OT patients and in AIDS patients caused a high inflammatory response as the TNF-α synthesis is not affected since monocytes are the major source this cytokine in response to soluble T. gondii antigens. IL-10 levels were almost similar in CT/AIDS and OT patients but low when compared with CHR individuals. The deviation to Th2 immune response including the production of anti-inflammatory cytokines, such as IL-10 may promote the parasites survival causing the tissue immune destruction. IL-10 production in T. gondii-infected brains may support the persistence of parasites as down-regulating the intracerebral immune response. All these indicate that OT and CT/AIDS patients produced low levels of IL-10 (Th2 response) and IFN-γ (Th1 response). They produced high TNF-α suggesting a high inflammatory response triggered by the parasite.

Genetic Susceptibility to Cardiac and Digestive Clinical Forms of Chronic Chagas Disease: Involvement of the CCR5 59029 A/G Polymorphism.

The clinical manifestations of chronic Chagas disease include the cardiac form of the disease and the digestive form. Not all the factors that act in the variable clinical course of this disease are known. This study investigated whether the CCR5Δ32 (rs333) and CCR5 59029 A/G (promoter region—rs1799987) polymorphisms of the CCR5 gene are associated with different clinical forms of chronic Chagas disease and with the severity of left ventricular systolic dysfunction in patients with chronic Chagas heart disease (CCHD). The antibodies anti-T. cruzi were identified by ELISA. PCR and PCR-RFLP were used to identify the CCR5Δ32 and CCR5 59029 A/G polymorphisms. The chi-square test was used to compare variables between groups. There was a higher frequency of the AA genotype in patients with CCHD compared with patients with the digestive form of the disease and the control group. The results also showed a high frequency of the AG genotype in patients with the digestive form of the disease compared to the other groups. The results of this study show that the CCR5Δ32 polymorphism does not seem to influence the different clinical manifestations of Chagas disease but there is involvement of the CCR5 59029 A/G polymorphism in susceptibility to the different forms of chronic Chagas disease. Besides, these polymorphisms do not influence left ventricular systolic dysfunction in patients with CCHD.

Association of the Functional MICA-129 Polymorphism With the Severity of Chronic Chagas Heart Disease

MICA-129 polymorphism affects the binding affinity of MICA molecules with the NKG2D receptor and influences effector cell function. The genotype met/met was associated with the severity of left ventricular systolic dysfunction (LVSD) in patients with chronic Chagas heart disease, while the val/val genotype was associated with the absence of LVSD.

Anti-Toxoplasma gondii antibodies in pregnant women and their newborn infants in the region of Sao Jose do Rio Preto, Sao Paulo, Brazil

CONTEXT AND OBJECTIVE Toxoplasmosis transmission during pregnancy can cause severe sequelae in fetuses and newborns. Maternal antibodies may be indicators of risk or immunity. The aim here was to evaluate seropositivity for anti-Toxoplasma gondii (anti-T. gondii) immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies and IgG avidity in pregnant women and their newborn infants. DESIGN AND SETTING Cross-sectional study in a high-risk pregnancy outpatient clinic. METHODS Serum samples from pregnant women (n = 87) and their respective newborns (n = 87) were evaluated for anti-T. gondii antibodies using indirect immunofluorescence (IIF) (IgM and IgG), enzyme-linked immunosorbent assay (ELISA) (IgG) and an avidity test. RESULTS Anti-T. gondii antibodies were identified in 64.4% of the serum samples from the mothers and their infants (56/87). Except for two maternal serum samples (2.3%), all others were negative for anti-T. gondii IgM antibodies, using IIF. The results showed that 92.9% of the pregnant women had high IgG avidity indexes (> 30%) and four samples had avidity indexes between 16 and 30%. Two women in the third trimester of pregnancy were positive for anti-T. gondii IgM antibodies; their babies had avidity indexes between 16 and 30%. The avidity indexes of serum from the other 83 newborns were similar to the results from their mothers. CONCLUSIONS The results showed that 2% of the pregnant women were at risk of T. gondii transmission during the gestational period. These data seem to reflect the real situation of gestational toxoplasmosis in the northwestern region of the state of São Paulo.

The ADA*2 allele of the adenosine deaminase gene (20q13.11) and recurrent spontaneous abortions: an age-dependent association

OBJECTIVE: Adenosine deaminase acts on adenosine and deoxyadenosine metabolism and modulates the immune response. The adenosine deaminase G22A polymorphism (20q.11.33) influences the level of adenosine deaminase enzyme expression, which seems to play a key role in maintaining pregnancy. The adenosine deaminase 2 phenotype has been associated with a protective effect against recurrent spontaneous abortions in European Caucasian women. The aim of this study was to investigate whether the G22A polymorphism of the adenosine deaminase gene is associated with recurrent spontaneous abortions in Brazilian women. METHODS: A total of 311 women were recruited to form two groups: G1, with a history of recurrent spontaneous abortions (N = 129), and G2, without a history of abortions (N = 182). Genomic DNA was extracted from peripheral blood with a commercial kit and PCR-RFLP analysis was used to identify the G22A genetic polymorphism. Fishers exact test and odds ratio values were used to compare the proportions of adenosine deaminase genotypes and alleles between women with and without a history of recurrent spontaneous abortion (p<0.05). The differences between mean values for categorical data were calculated using unpaired t tests. The Hardy-Weinberg equilibrium was assessed with a chi-square test. RESULTS: Statistically significant differences were identified for the frequencies of adenosine deaminase genotypes and alleles between the G1 and G2 groups when adjusted for maternal age. CONCLUSIONS: The results suggest that the adenosine deaminase *2 allele is associated with a low risk for recurrent spontaneous abortions, but this association is dependent on older age.

Total IgE plasma levels vary according to gender and age in Brazilian patients with allergic rhinitis

OBJECTIVE: Allergic rhinitis is a disease that affects the upper airways and causes inflammation of the nasal mucosa and it is mediated by IgE antibodies produced after sensitization to environmental allergens. Previous reports have indicated that this disease affects males more often than females. The objective of this study was to verify whether total IgE plasma levels vary between genders in patients suffering from allergic rhinitis. METHODS: A total of 171 adult patients suffering from allergic rhinitis (55 males and 116 females) were enrolled. Total IgE plasma levels were determined using commercial kits, with 140 IU/mL considered as a reference value. The mean total IgE plasma levels were compared according to gender and age. RESULTS: The mean age of the overall patient group with allergic rhinitis was 38.4±19.0 years and a significant difference in age was observed between genders (males: 32.2±17.8 years; females: 41.4±18.9 years; p = 0.0027). Additionally, the mean total IgE plasma levels were higher in males (413.0±143.0 IU/mL) than in females (147.9±98.0 IU/mL) (p<0.0001). These differences persisted even when males and females were stratified by age (up to or older than 20 years of age). CONCLUSIONS: In conclusion, total IgE plasma levels are higher in young adult males than in females suffering from allergic rhinitis. Evaluating total IgE plasma levels can be useful to identify patients at risk of allergic rhinitis in areas with low industrial pollution.

Long-Term Viruria in Zika Virus-Infected Pregnant Women, Brazil, 2016

During the 2016 Zika virus outbreak in Brazil, we detected Zika virus RNA in urine samples collected from Zika virus–positive pregnant women during different stages of pregnancy. Women had positive and negative intervals of viruria; 3 newborns had adverse outcomes. Further research is needed to clarify the relationship between viruria and outcomes for newborns.

The role of CCR5 in Chagas disease - a systematic review

Chagas disease is an infection caused by the protozoan Trypanosoma cruzi. The clinical manifestations result from the chronic forms of the disease: indeterminate, cardiac, digestive or mixed. The pathogenesis of this disease is related to the genetic variability of both the parasite and the host with polymorphisms of genes involved in immune response possibly being involved in the variable clinical course. Cytokines play a key role in regulating immune response, in particular chemokines exert a crucial role in the control of leukocyte migration during the hosts response to infectious processes. Furthermore, inflammatory cytokines and chemokines have been implicated in the generation of inflammatory infiltrates and tissue damage. The involvement of the CC Chemokine Receptor 5 (CCR5) in leukocyte migration to sites of inflammation has been elucidated and this receptor has been investigated in Chagas disease. Here we review the role of CCR5 in T. cruzi infection as well as its importance in the pathogenesis of the Chagas disease.

MHC Class I Chain-Related Gene A Polymorphisms and Linkage Disequilibrium with HLA-B and HLA-C Alleles in Ocular Toxoplasmosis

This study investigated whether polymorphisms of the MICA (major histocompatibility complex class I chain-related gene A) gene are associated with eye lesions due to Toxoplasma gondii infection in a group of immunocompetent patients from southeastern Brazil. The study enrolled 297 patients with serological diagnosis of toxoplasmosis. Participants were classified into two distinct groups after conducting fundoscopic exams according to the presence (n = 148) or absence (n = 149) of ocular scars/lesions due to toxoplasmosis. The group of patients with scars/lesions was further subdivided into two groups according to the type of the ocular manifestation observed: primary (n = 120) or recurrent (n = 28). Genotyping of the MICA and HLA alleles was performed by the polymerase chain reaction-sequence specific oligonucleotide technique (PCR-SSO; One Lambda®) and the MICA-129 polymorphism (rs1051792) was identified by nested polymerase chain reaction (PCR-RFLP). Significant associations involving MICA polymorphisms were not found. Although the MICA*002~HLA-B*35 haplotype was associated with increased risk of developing ocular toxoplasmosis (P-value = 0.04; OR = 2.20; 95% CI = 1.05–4.60), and the MICA*008~HLA-C*07 haplotype was associated with protection against the development of manifestations of ocular toxoplasmosis (P-value = 0.009; OR: 0.44; 95% CI: 0.22–0.76), these associations were not statistically significant after adjusting for multiple comparisons. MICA polymorphisms do not appear to influence the development of ocular lesions in patients diagnosed with toxoplasmosis in this study population.