Use of Phadiatop Infant in diagnosis of specific sensitization in young children with wheeze or eczema

Lack of Consistent Association between Asthma, Allergic Diseases, and Intestinal Helminth Infection in School-Aged Children in the Province of Bengo, Angola

Epidemiological studies have shown conflicting findings on the relationship between asthma, atopy, and intestinal helminth infections. There are no such studies from Angola; therefore, we aimed to evaluate the relationship between asthma, allergic diseases, atopy, and intestinal helminth infection in Angolan schoolchildren. We performed a cross-sectional study of schoolchildren between September and November 2017. Five schools (three urban, two rural) were randomly selected. Asthma, rhinoconjunctivitis, and eczema were defined by appropriate symptoms in the previous 12 months: atopy was defined by positive skin prick tests (SPT) or aeroallergen-specific IgE; intestinal helminths were detected by faecal sample microscopy. In total, 1023 children were evaluated (48.4% female; 57.6% aged 10–14 years; 60.5% urban). Asthma, rhinoconjunctivitis, or eczema were present in 9%, 6%, and 16% of the studies children, respectively. Only 8% of children had positive SPT, but 64% had positive sIgE. Additionally, 40% were infected with any intestinal helminth (A. lumbricoides 25.9%, T. trichiura 7.6%, and H. nana 6.3%). There were no consistent associations between intestinal helminth infections and asthma, allergic diseases, or atopy, except for A. lumbricoides, which was inversely associated with rhinoconjuctivitis and directly associated with aeroallergen-specific IgE. We concluded that, overall, intestinal helminth infections were not consistently associated with allergic symptoms or atopy. Future, preferably longitudinal, studies should collect more detailed information on helminth infections as part of clusters of environmental determinants of allergies.

Phadiatop, Phadiatop Infant and total IgE evaluated in allergic Brazilian children and adolescents

The clinical history is of importance in the investigation of allergic diseases but does have limitations. Many allergic conditions will be over-diagnosed if anamnesis alone is used for diagnostic criteria. Serum total immunoglobulin E (TIgE) quantification, as well as panels containing allergens prevalent in the studied population, may serve as screening tests and facilitate the diagnosis of allergic disease or its exclusion. We assessed the positivity of two versions of these tests, Phadiatop Europe® (PhEU) and Phadiatop Infant® (PhInf), as well as total IgE (TigE) values in patients with a medical diagnosis of allergic disease and non-allergic individuals.

METHODS

A cross-sectional study performed in eleven Brazilian pediatric allergy centers with patients divided into groups according to the primary condition and a group of assessed control subjects. They were submitted to TIgE measurement and screening tests (PhEu and PhInf).

RESULTS

TIgE mean serum levels were significantly higher among allergic patients, especially those with asthma/rhinitis or atopic dermatitis. The positivity of the screening tests, considering the total population, was 63.8% for PhEU and 72.6% for PhInf. These increased when we evaluated only the allergic subjects. The concordance index of the two tests was Kappa=0.7 and higher among those of greater age.

CONCLUSIONS

In the assessed population, there were significantly higher levels among those with positive screening tests and PhInf showed better performance in the identification of sensitized individuals, regardless of age. This is the first study to evaluate Phadiatop and Phadiatop Infant in the same population.

Asthma-related outcomes associated with indoor air pollutants among schoolchildren from four informal settlements in two municipalities in the Western Cape Province of South Africa

The health impact of indoor air pollution in informal settlement households has not been extensively studied in South Africa. This cross-sectional study investigated the association between asthma and common indoor exposures among schoolchildren from four informal settlements located in two municipalities in the Western Cape Province. A total of 590 children, aged 9-11 years, were recruited. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered to caregivers. Pulmonary function assessment included spirometry and fractional exhaled nitric oxide (FeNO). Phadiatop test for atopy was done. The prevalence of doctor-diagnosed asthma was 3.4% (n = 20) among whom only 50% were on treatment. The prevalence of current wheeze was 12.9%, and 17.6% had airway obstruction (FEV₁  < lower limit of normal), while 10.2% had airway inflammation (FeNO > 35 ppb). In adjusted logistic regression models, dampness, visible mold growth, paraffin use for cooking, and passive smoking were associated with a twofold to threefold increased risk in upper and lower airway outcomes. The strongest association was that of visible mold growth with rhinitis (adjusted odds ratio-aOR 3.37, 95% CI: 1.69-6.71). Thus, there is a need for improved diagnosis of childhood asthma and Indoor Air Quality in informal settlement households.

Faecal eosinophil cationic protein and serum immunoglobulin E in relation to infant feeding practices

Background To date, the effects of exclusive breastfeeding duration and timing of solid food introduction on allergy prevention are unclear. The aim of this study was to determine the effect of variable feeding practices on intestinal inflammation in infants using faecal eosinophil cationic protein as a surrogate marker and to assess whether faecal eosinophil cationic protein is associated with serum immunoglobulin E. Methods Subjects ( n = 206) were enrolled from the Prediction of Allergies in Taiwanese CHildren (PATCH) birth cohort study. Stool samples were collected at 6 and 12 months for determining eosinophil cationic protein, and blood was collected for determining total and allergen-specific immunoglobulin E at 12 months. We compared these biomarkers between infants with variable exclusive breastfeeding duration and infants introduced to solid foods at various periods. The association between faecal eosinophil cationic protein, total serum immunoglobulin E and specific immunoglobulin E was also analysed. Results Faecal eosinophil cationic protein was significantly higher in exclusively breastfed infants compared with formula-fed infants and infants who were not exclusively breastfed at 6 months of age ( P < 0.05). At 12 months, infants who were introduced to solid foods at 5-6 months had the lowest faecal eosinophil cationic protein compared with those who were introduced at earlier and later periods. There was no significant association between faecal eosinophil cationic protein and serum immunoglobulin E. Conclusion We found that breastfeeding exclusively for >6 months did not reduce serum immunoglobulin E, but rather increased intestinal inflammation. Faecal eosinophil cationic protein was not associated with total serum immunoglobulin E and specific immunoglobulin E and might not be a useful indictor of immunoglobulin E sensitization in infancy.

Phadiatop Infant(®) detects IgE-mediated diseases among pre-school children: a prospective study

BACKGROUND

IgE-sensitization to food and inhalant allergens may precede and accompany the appearance of clinical symptoms of allergic diseases. The aim was to study the diagnostic capacity of Phadiatop(®) Infant (Phinf) for detecting IgE-sensitization at 5 yr of age and further to evaluate the predictive capacity of Phinf longitudinally with regard to sensitization and allergic symptoms in pre-school children.

METHODS

Two hundred and one children with complete data on sIgE testing for 10 individual allergens, Phinf analyses, and clinical evaluations at 2 and 5 yr of age were evaluated.

RESULTS

The diagnostic performance of Phinf, applied at the age of 5 and compared to specific IgE testing, gave a sensitivity of 84% and a specificity of 98%. The positive and negative predictive values were 97% and 92%, respectively. A positive Phinf test at 2 yr increased the odds 35.6-fold (95% CI 11.8-107) for IgE-sensitization and 14.7-fold (95% CI 4.4-49.7) for any allergic symptom at 5 yr of age. The association (OR) between Phinf and current symptoms was, at 2 and 5 yr of age, 3.6 (95% CI 1.6-7.9) and 18.4 (95% CI 7.4-45.8), respectively.

CONCLUSIONS

Phinf seems to be a reliable tool for predicting future sensitization as well as allergic symptoms in young children.

[Clinical manifestations of atopy in children up to two years of age]

BACKGROUND/AIM

Atopic diseases such as atopic dermatitis, allergic rhinitis and asthma have had increased prevalence during the past decade and nowadays occur in every third child in developed countries. The aim of the study was to determine frequency and type of atopic diseases at the age of two, as well as the importance the total IgE antibodies concentrations have in diagnosis and prognosis of the disease.

METHODS

The study involved 175 children up to two years of age. Allergy-like symptoms were found after surveying their parents and pediatric medical records. Using the fluorescence immunossay (FIA) method, total IgE antibodies concentrations and specific IgE antibodies (Phadiatop infant) were determined on an Immunocap 100 Dyagnostic System.

RESULTS

One or more allergy-like symptoms accounted for 57.7% of findings in children under the age of two, whilst in 19.4% the existence of IgE-related allergic diseases was found. Atopic diseases usually have clinical manifestations of atopic dermatitis (11.4%), IgE-bound wheezing/asthma (10.8%) and food allergies (7.4%), and to much lesser extent those of allergic rhinitis (3.4%) and urticaria (1.7%). The significantly higher total IgE antibodies concentrations were found in children with allergy-like symptoms (p < 0.0005) (cut-off 15.15 kU/L, sensitivity 76.5% specificity 71.6%).

CONCLUSION

Almost 20% of two-year-old children have any of clinically manifested allergic diseases, with atopic dermatitis and IgE wheeze/asthma being predominant. The higher total IgE antibodies concentration is a good marker for sensitization in children with allergy-like symptoms.

Accuracy of ImmunoCAP Rapid in the diagnosis of allergic sensitization in children between 1 and 14 years with recurrent wheezing: the IReNE study

It is estimated that at least one out of three children with recurrent wheezing is atopic. Reliable diagnostic tools are needed in primary care that allow for adequate identification of these children. The purpose of this study was to assess the value of ImmunoCAP Rapid (ICR) Wheeze-Rhinitis Child in the identification of atopy with the use of 10 selected allergens in children with recurrent episodes of wheezing. A multicenter population study is based on primary care. It included children managed consecutively at the health center, who had three or more episodes of wheezing, at least one of them in the last 12 months. Each child completed a physical examination, an epidemiological survey, one capillary blood sampling (110 microl) for ICR, and one venous blood sampling for determination of Phadiatop Infant, total IgE and 10 specific IgE measurements. The children were identified as atopic, based on their clinical signs and symptoms and at least one positive specific IgE (0.35 kU(A)/l or higher), before knowing the results of ICR, Phadiatop Infant and total IgE. ICR was read by two independent observers. Six classes were evaluated, negative without any color and five positive degrees of pink-red color. Two hundred and fifteen children aged between 1 and 14 years were studied (138 boys); 50.7% were identified as atopic, 39.1% were sensitized only to inhalant allergens, 6.5% to food allergens and 5.1% to both. The predominant allergen was the dust mite (39.3%). For ICR, there were 2134 valid double observations. The Kappa index, comparing the negative results vs. any positive result, was 0.91 (95% CI: 0.88-0.94). The intraclass correlation coefficient was 0.98 (95% CI: 0.98-0.99). In the identification of a child as atopic, the positive post-test probability of ICR depended on the color degrees considered: 88.4% for any positive and 97.6% for the most intense tones. The positive post-test probability of Phadiatop Infant and total IgE was 95.6% and 68.2% respectively. ICR showed good reliability for the most prevalent allergen, the dust mite, with a sensitivity of 90.5% (95% CI: 82.1-95.8) and specificity of 88.5% (95% CI: 81.7-93.4). The analysis of the other allergens was limited by the small number of sensitized children. The analysis of receiver operating characteristic curves revealed an area under the curve of 0.84 (95% CI 0.80-0.88) for the cut-off point of specific IgE of 0.35 kU(A)/l and of 0.94(CI 0.91-0.97) for 2 kU(A)/l. A greater intensity of color of the lines of ICR was related to higher levels of specific IgE in blood. ICR is a reliable test for the identification of atopy in children, which identifies most children as atopic, and shows a good correlation in allergen-by-allergen identification. This suggests that it should be regarded as a first-rate tool, in the primary care clinic, for the evaluation of children with recurrent wheezing.

Phadiatop infant in the diagnosis of atopy in children with allergy-like symptoms

Background and Objective. Allergy-like symptoms such as wheezing and eczema are common in young children and an early diagnosis is important to initiate correct management. The objective of this study was to evaluate the diagnostic performance of Phadiatop Infant, an in vitro test for determination of early sensitisation to food and inhalant allergens. Patients and Methods. The study was conducted, retrospectively, using frozen sera from 122 children (median age 2.7 years) admitted to the hospital with suspected allergic symptoms. The doctor's diagnosis atopic/nonatopic was based on routinely used procedures such as clinical evaluation, SPT, total and allergen-specific IgE antibodies. The performance of Phadiatop Infant was evaluated in a blinded manner against this diagnosis. Results. Eighty-four of the 86 children classified as atopic showed a positive Phadiatop Infant test. Thirty-six were classified as nonatopic, 32 of who had a negative test. With a prevalence of atopy of 70% in this population, this gives a sensitivity of 98%, a specificity of 89%, and a positive and negative predictive value of 95% and 94%, respectively. Conclusion. The results from the present study suggest that Phadiatop Infant could be recommended as a complement to the clinical information in the differential diagnosis on IgE-mediated disease in young children with allergy-like symptoms.