ABSTRACT Dengue is a global and growing health threat, especially in Southeast Asia, West Pacific and South America. Infection by the dengue virus (DENV) results in dengue fever, which can evolve to severe forms. Cytokines, especially interferons, are involved in the immunopathogenesis of dengue fever, and so may influence the disease outcomes. The aim of this study was to investigate the association between severe forms of dengue and two single nucleotide polymorphisms (SNPs) in the interferon-gamma gene (IFNG): A256G (rs2069716) and A325G (rs2069727). We included 274 patients infected with DENV serotype 3: 119 cases of dengue without warning signs (DWoWS), and 155 with warning signs (DWWS) or severe dengue (SD). DNA was extracted, and genotyped with Illumina Genotyping Kit or real time PCR (TaqMan probes). We estimated the adjusted Odds Ratios (OR) by multivariate logistic regression models. When comparing with the ancestral AA/AA diplotype (A256G/A325G), we found a protective association of the AA/AG against DWWS/SD among patients with secondary dengue (OR 0.51; 95% IC 0.24-1.10, p = 0.085), adjusting for age and sex. The variant genotype at locus A325G of the IFNG, in combination with the ancestral genotype at locus A256G, can protect against severe clinical forms of secondary dengue in Brazilian DENV3-infected patients.

Abstract INTRODUCTION Suckling by schistosomotic mice improves anti-ovalbumin (OA) antibody production, while delayed-type hypersensitivity (DTH) remains unaffected. This property of milk from schistosomotic mice was investigated in IL-12/IL-23-deficient mice (IL-12p40KO). METHODS We compared anti-OA DTH, IgG2a and cytokines in wild-type and IL-12p40KO mice suckled by infected (SIM) or non-infected (CONTROL) mothers. RESULTS SIM mice showed similar intensity and eosinophils in the DTH, which was abolished in IL-12p40KO and IL-12p40KO-SIM mice. In IL-12p40KO-SIM, IgG2a and TGF-β levels were higher, but IL-6 levels were lower. CONCLUSIONS Milk from schistosomotic mothers may evoke IgG2a without eliciting DTH in IL-12/IL-23 deficiencies, by changing TGF-β/IL-6 levels.

Abstract INTRODUCTION The functioning of the immune system during pregnancy is altered in both human immunodeficiency virus (HIV)-infected and uninfected women. Unfavorable socioeconomic conditions have been indicative of higher morbidity and mortality and worsening of the immune system. The aim of this study was to correlate social status with levels of interleukin (IL)-10 (non-inflammatory) and interferon-gamma (IFN-γ; inflammatory) cytokines. METHODS A cross-sectional study was conducted with three groups of women: 33 pregnant HIV-infected (G1); 40 non-pregnant, HIV-infected (G2); and 35 pregnant, HIV-uninfected. To measure the social status, a compound indicator called the social status index (SSI), was established using sociodemographic variables (i.e., education level, housing conditions, per capita income, and habitation and sanitary conditions). RESULTS The HIV-infected women had a higher proportion of unfavorable SSI (73% and 75% of G1 and G2, respectively). There were significantly lower IL-10 levels in the G1 group with both unfavorable and favorable SSI than in the other groups. No significant difference in IFN-γ levels was observed among groups. However, the G1 group had higher IFN-γ values among both favorable and unfavorable SSI groups. CONCLUSIONS Higher rates of unfavorable conditions, including lower education levels, IL-10 levels, and a trend for higher IFN-γ levels, were identified among HIV-infected women, pregnant and non-pregnant. These factors may interfere in health care and lead to poor outcomes during pregnancy. Therefore, we suggest that health policies could be created to specifically address these factors in this population.

RESUMO CONTEXTO A fibrose periportal é a maior consequência patológica da infecção pelo Schistosoma mansoni. OBJETIVO Avaliar a acurácia de marcadores séricos e construir um índice para avaliar a fibrose. MÉTODOS Pacientes (n=116) com esquistossomose foram avaliados pela ultrassonografia e dosados os níveis de aminotransferases, γ-glutamil transferase, fosfatase alcalina, ácido hialurônico, citocinas e plaquetas. Imagens de ultrasom foram utilizadas para avaliar a fibrose através de classificação de Niamey e identificados 19 pacientes sem fibrose periportal (padrão A e B), 48 com fibrose média a moderada (C e D) e 49 com fibrose avançada (E e F). RESULTADOS Através de análise multivariada, um modelo foi criado, que envolveu a fosfatase alcalina e plaquetas e conseguiu separar pacientes com diferentes padrões de fibrose periportal. Este índice mostrou um melhor desempenho em separar pacientes sem fibrose dos pacientes com fibrose avançada. O índice biológico mostrou uma área sob a curva ROC de 1,000. Usando valores infereiores e acima do ponto de corte, a presença ou ausência de fibrose avançada pode ser prevista em todos os pacientes. CONCLUSÃO O índice construído pode ser usado para separar os pacientes com diferentes padrões de fibrose periportal, especialmente para prever fibrose avançada em pacientes com esquistossomose.

ABSTRACT BACKGROUND Periportal fibrosis is the major pathological consequence of the Schistosoma mansoni infection. OBJECTIVE To evaluate the accuracy of serum markers and to construct an index to assess fibrosis. METHODS Patients (n=116) with schistosomiasis were evaluated by ultrasound scan and measurements of serum levels of aminotransferases, γ-glutamyl transferase, alkaline phosphatase, hyaluronic acid, cytokines and platelets. Ultrasound images were used to evaluate the fibrosis using Niamey's classification and identified 19 patients without periportal fibrosis (patterns A and B), 48 with mild to moderate fibrosis (C and D) and 49 with advanced fibrosis (E and F). RESULTS Using multivariate analysis, a model was created, which involved alkaline phosphatase and platelets and could separate patients with different patterns of fibrosis. This index showed a better performance in separating patients without fibrosis from with advanced periportal fibrosis. The biological index showed an area under the ROC curve of 1.000. Using values below the lowest or above the highest cut-off point, the presence or absence of advanced fibrosis could be predicted in all patients. CONCLUSION The index constructed can be used to separate patients with different patterns of periportal fibrosis, specially to predict advanced fibrosis in schistosomiasis patients.

Liver biopsy is the gold-standard method to stage fibrosis; however, it is an invasive procedure and is potentially dangerous. The main objective of this study was to evaluate biological markers, such as cytokines IL-13, IFN-γ, TNF-α and TGF-β, platelets, bilirubins (Bil), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), total proteins, γ-glutamil transferase (γ-GT) and alkaline phosphatase (AP), that could be used to predict the severity of hepatic fibrosis in schistosomiasis and hepatitis C (HC) as isolated diseases or co-infections. The following patient groups were selected: HC (n = 39), HC/hepatosplenic schistosomiasis (HSS) (n = 19), HSS (n = 22) and a control group (n = 13). ANOVA and ROC curves were used for statistical analysis. P < 0.05 was considered significant. With HC patients we showed that TNF-α (p = 0.020) and AP (p = 0.005) could differentiate mild and severe fibrosis. With regard to necroinflammatory activity, AST (p = 0.002), γ-GT (p = 0.034) and AP (p = 0.001) were the best markers to differentiate mild and severe activity. In HC + HSS patients, total Bil (p = 0.008) was capable of differentiating between mild and severe fibrosis. In conclusion, our study was able to suggest biological markers that are non-invasive candidates to evaluate fibrosis and necroinflammatory activity in HC and HC + HSS.

The production and regulation of interleukin (IL) IL-13, IL-4 and interferon-gamma (IFN-³) was evaluated in 43 schistosomiasis patients with different clinical forms. Whole-blood cultures cytokine production in response to soluble egg antigen (SEA), soluble worm adult preparation (SWAP), mitogens, neutralizing antibodies or recombinant IL-13 were measured by ELISA. After SWAP stimulation, chronic patients, particularly hepatointestinals, produced higher levels of IL-4 in comparison with acute patients, suggesting the presence of a type 2 cytokine profile in these patients. Following SEA and SWAP stimulation, hepatosplenic (HS) patients showed increased levels of IFN-³ when compared with acute patients, indicating that HS disease in humans is associated with a type 1 cytokine response. The mechanisms of immune regulation are apparently different between the clinical stages of the disease, some of which are antigen-specific.