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Most food allergy cases are associated with a limited group of allergens. This could be attributed to an increased ability of some foods to sensitize and trigger allergic reactions. However, there are no validated animal models to evaluate the sensitizing or allergenic potentials of proteins. Our aim was to evaluate three protocols of adjuvant-free intraperitoneal sensitization that differ in the time points for sample collection (days 14, 28 and 35 from beginning of the sensitization) and also in the number of immunizations (2, 5 and 3, respectively). Ovalbumin (OVA; 0.05 mg), cow milk proteins (CMP; 0.025, 0.05 and 0.25 mg), and potato acid phosphatase (PAP; low allergenic protein; 250.0 mg) were administered intraperitoneally (ip) to BALB/c mice (n = 4–6) and the protein-specific IgE and IgG antibody responses were evaluated using ELISA. Additional serum protein-specific IgE antibodies evaluations were carried out after IgG depletion. Anti-OVA IgE antibodies were detected in mice from all three protocols. The responses were higher in the group of mice that underwent the 28-day protocol than in those that underwent the 14- or 35-day protocols (p < 0.01 and p < 0.05, respectively). Anti-CMP IgE antibodies were detected in both the 14- and 28-day protocols, but the response was higher in the group that underwent the 28-day protocol (p < 0.001). The anti-CMP IgE antibody response detection was improved after serum IgG depletion (p < 0.001). Anti-PAP IgE antibodies were not detected. Mice with undetectable serum levels of protein-specific IgE triggered anti-OVA, -CMP, and -PAP IgG responses. An adjuvant-free 28-day protocol with five ip immunizations seems appropriate for evaluation of the inherent sensitizing or allergenic capacity of the studied proteins. Reproducible results were obtained utilizing the BALB/c mouse strain. Inter-laboratory studies including a larger number of proteins should be carried out to validate this model. [ABSTRACT FROM AUTHOR]

Background: Dengue manifestations can range from subclinical to fatal. The study of factors that influence dengue's clinical severity can provide information to potentially limit or predict severe cases. Secondary infection (SI) with a different dengue serotype has been recognized as an important determinant of severity. However, severe dengue (SD) manifestations, including shock, can happen during primary infection (PI) too and the mechanisms involved are less understood. To characterize the severe manifestations associated to PI, we distinguished between primary and secondary dengue cases in hospitalized patients from a region of low and recent dengue incidence in central Mexico. This region can serve as a model for dengue's behavior as it spreads to new areas worldwide. Methods: Dengue-specific immunoglobulin M (IgM) and IgG concentrations were measured in the serum of 78 hospitalized patients with dengue hemorrhagic fever, and their ratios were used to discriminate between PI and SI, as recommended by World Health Organization. Clinical and laboratory manifestations were compared between PI and SI. Results and Conclusions: PI was detected in 23% of hospitalized dengue cases, a proportion similar to that reported in high-incidence regions in Mexico. PI was more frequent in 16- to 40-year-olds, and was absent in patients older than 60 years. Only dengue with warning signs and SD were present in the studied population of hospitalized patients, and case frequency decreased with clinical severity both in PI and SI groups. No significant differences in demographics, laboratory tests, or symptoms were found between PI and SI, which illustrates that cases requiring hospitalization during outbreaks can be severe, even if they are PI. This information can help plan for sanitary contingencies in places where dengue is recently emergent and numerous PI cases are expected. The mechanisms involved in PI clinical severity need to be studied further.

Background: The prevalence of gluten-related disorders (GRD) and adherence to a gluten-free diet (GFD) remains unknown in Brazilian population and there is no published information on the scientific literature about the proportion of Brazilians that were diagnosed with a gluten-related disorder. Thus, the aim of this work was to estimate the prevalence of GRDs and adherence to a GFD by self-report in adult Brazilian population., Materials and Methods: A questionnaire-based cross-sectional study was conducted in two Brazilian cities., Results: The response rate was 93.2% (1630/1749). The self-reported prevalence rates were (95% CI): adverse reactions to gluten 10.06% (8.64-11.62); gluten sensitivity 2.33% (1.65-3.18); physician-diagnosed celiac disease 0.3% (0.09-0.71); non-celiac gluten sensitivity 1.71% (1.14-2.47); wheat allergy 0.79% (0.42-1.36); adherence to gluten-free diet 7.48% (6.25-8.87); gluten avoiders 15.21% (13.5-17.05). Among those who were following a GFD ( n = 122), 65.6% ( n = 80) of them reported that they did not develop symptoms after wheat/gluten ingestion and 50% ( n = 61) were following the diet without medical/dietitian advice. The main motivation for following a GFD in the self-reported and non-self-reported gluten sensitivity groups were the symptoms triggered after wheat/gluten ingestion (86.8%) and weight control (57.1%), respectively., Conclusions: Implementation of programs to increase awareness about GRDs among healthcare professionals and giving scientifically sound information to the general population about the risks and benefits for following a GFD are desirable actions in Brazil. The results also add to the growing body of evidence for highlighting the under-diagnosis of GRD and the trend for following a GFD in Latin America.