Laboratory screening test with inhalant and food allergens in atopic Brazilian children and adolescents: a performance.

The Phadiatop Infant® (PhInf) is a panel developed to assess allergic sensitization (immunoglobulin E [IgE]) in children aged <5 years and combines inhalant and food allergens. The test has not been evaluated outside Europe. This is a cross-sectional study conducted at 11 pediatric allergy centers to evaluate PhInf as an allergic disease screening method in Brazilian children. Children as controls and patients (aged 6 months-18 years) were grouped according to their primary disease and age group. PhInf and specific serum IgE (sIgE) screening was performed for Dermatophagoides pteronyssinus (DP), cat and dog epithelia, a mix of grasses and pollens, eggs, cow's milk, peanuts, and shrimp. Values ≥ 0.35 kUA/L (or PAU/L) were considered positive. A total of 470 children and adolescents, which included 385 patients and 85 controls, participated in the study (47.7% boys, average age: 6.3 years). In all, 72.6% of the participants had positive PhInf test (n = 341), with a higher proportion of those having food allergy (92.6%), atopic dermatitis (91.9%), and those aged >13 years having allergy (95%). The PhInf and sIgE agreement between patients (Kappa = 0.94, P < 0.001) and controls (Kappa = 0.84, P < 0.001) was high. PhInf and DP agreement in patients aged >13 years was excellent (Kappa = 0.936, P < 0.001). Compared with sIgE dosage, PhInf had high sensitivity (97%) and specificity (93%). Positivity of PhInf test in this population was high and had an excellent correlation with the allergens comprising the panel. It is a useful method for screening children suspected of having allergic diseases in a non-European country.

Respiratory viruses in pediatric necropsies: an immunohistochemical study.

Infections of the respiratory system are responsible for the majority of hospitalizations and deaths in pediatric patients in developing countries. We selected 177 necropsies of pediatric patients who died as a result of serious respiratory infections. The histopathological findings and epidemiological data were reviewed, and lung tissue samples were separated for immunohistochemistry testing. Conventional immunohistochemistry techniques were used to detect viral antigens in formalin-fixed, paraffin-embedded (FF-PE) lung tissue samples using a pool of monoclonal antibodies against respiratory viruses (respiratory syncytial virus, influenza A and B, adenovirus, and parainfluenza 1, 2, and 3 viruses) as primary antibodies. The histopathological findings were classified into bronchopneumonia (BCP) and interstitial pneumonitis (IP) patterns. The immunohistochemistry results were compared with histopathological patterns and epidemiological data. Positive results for viruses were found in 34% and 62.5% of the BCP and IP cases, respectively. Males and infants below 1 year of age were more frequent in the group that had positive results for viruses. Acute enteritis was the main cause of hospitalization and sepsis the most frequent cause of death in this group. A clear seasonal distribution was observed, with the majority of cases occurring in the 2nd and 3rd trimesters (autumn and winter) of each year in the period studied. Immunohistochemistry is an affordable and easy-to-perform method for viral-antigen detection in FF-PE tissue samples. Although BCP is a classic histopathological pattern found in bacterial infections, it is possible that children with serious respiratory infections had concomitant viral and bacterial infections, regardless of their previous immunologic state.