Décio Medeiros

Total IgE level in respiratory allergy: study of patients at high risk for helminthic infection

OBJECTIVE Eosinophilia and increased serum IgE levels are indicators of atopy; however, other factors can also play a key role, such as intestinal parasitic infections. This study assesses the relationship between total serum IgE, eosinophil count, and anti-Ascaris IgE in individuals with asthma and/or allergic rhinitis. METHODS A cross-sectional study was carried out in adolescents with asthma and/or allergic rhinitis. The patients had their total serum IgE, anti-Ascaris IgE and eosinophil count measured. RESULTS A total of 101 patients aged 12 to 21 years were assessed. Median IgE level was 660 IU/mL (P(25-75) 243.5-1500), and the eosinophil count corresponded to 510 cells/mm(3) (P(25-75) 284-811). Anti-Ascaris IgE was positive in 73% (74/101) of the individuals, but parasitological stool examination yielded positive results in only 33.7% (34/101). The correlation coefficients were the following: 0.34 (p = 0.001) between total IgE level and eosinophil count, 0.52 (p < 0.001) between total IgE level and anti-Ascaris IgE, and 0.26 (p = 0.01) between eosinophil count and anti-Ascaris IgE. The final multiple linear regression model pointed out that anti-Ascaris IgE contributed to a total serum IgE level with a coefficient of determination (adjusted R(2)) of 0.25 (F = 12.35; p < 0.001). This effect occurred regardless of eosinophil count and of the presence of intestinal helminthic infection. CONCLUSION In patients with respiratory allergy and increased total serum IgE levels living in areas where there is a high risk for helminthic infections, the quantification of anti-Ascaris IgE can be more useful and more insightful than the parasitological stool examination.

Prevalência de sibilância e fatores de risco associados em crianças no primeiro ano de vida, residentes no Município de Recife, Pernambuco, Brasil

Verificar a prevalencia de sibilância no primeiro ano de vida em lactentes da cidade do Recife, Pernambuco, Brasil e identificar fatores de risco a ela associados. Estudo realizado segundo o protocolo do Estudio Internacional de Sibilancia en Lactantes (EISL) em criancas com idades entre 12 e 15 meses. A amostra foi analisada segundo a presenca ou nao de sibilância. Foram entrevistados 1.071 pais por criancas com idades entre 12 e 15 meses. A prevalencia de sibilância no primeiro ano de vida foi de 43%, sem diferencas quanto aos generos. O relato de sibilância no primeiro ano de vida foi associado a ter tido pneumonia, ter familiares com asma, mais de nove episodios de infeccoes de vias aereas superiores e primeiro episodio de resfriado antes de seis meses de idade (p < 0,001). A prevalencia de sibilância no primeiro ano de vida entre lactentes da cidade do Recife e alta. Inicio precoce e numero elevado de resfriados, ter familiares com asma e ter pneumonia foram fatores associados aos quadros de sibilância nessas criancas.

Production of interleukin-10 in asthmatic children after Beta-1-3-glucan

BACKGROUND Beta-1-3 Glucan is a polysaccharide extracted from Saccharomyces cerevisiae with a possible immunomodulating action that may have a favourable action on asthma symptoms and other allergic diseases. An experimental study carried out using a murine respiratory model detected a decrease in pulmonary tissue eosinophilia, as well as an increase in Interleukin-10 (IL-10) after glucan use. METHODS This open, exploratory study with blind outcome evaluation included asthmatic children between 6 and 12 years of age with mild to moderate persistent asthma and inadequate disease control (rescue medication needed more than twice a week) in spite of inhaled budesonide 400 microg/day. After a four week run-in period, subcutaneous Beta-1-3-glucan injections were given weekly for the first four weeks and then every two weeks for the last four weeks. IL-10 levels, measured by the immunoenzymatic method (ELISA), were compared before and after glucan administration. RESULTS Twenty patients (14 male and 6 female) were included. Mean IL-10 levels were 6.4 pg/ml and 11.3 pg/ml before and after glucan, respectively (p = 0.02). There was also a reduction of asthmatic symptoms score at the end of study. CONCLUSIONS This is the first study which shows that subcutaneous particulate Beta-1-3-glucan increases serum IL-10 levels in asthmatics. The possibility of glucan being able to modulate allergic sensitisation and having a beneficial action in restoring Th2 function should be assessed by means of properly planned controlled clinical trials, as it may represent a new therapeutic strategy.

Sensitisation to aeroallergens among asthmatic and non-asthmatic adolescents living in a poor region in the Northeast of Brazil

OBJECTIVES To assess the kind and frequency of sensitisation to aeroallergens (skin prick test - SPT) of asthmatic and non-asthmatic adolescents (13-14 years old) living in the city of Caruaru, Northeast of Brazil, and to analyse their exposure to some environmental factors. METHOD A case-control study was conducted with asthmatic (50) and non-asthmatic (150) adolescents diagnosed by the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire. All were submitted to SPT with aeroallergens (house dust mites, cat and dog epithelium, cockroaches, moulds and grass) and completed a questionnaire to evaluate their environmental exposure. RESULTS There were no significant differences between groups regarding gender, age, number of siblings and environmental exposure. Asthmatic subjects exhibited a higher frequency of positive SPTs than non-asthmatic subjects (54.0% vs 33.3%, p=0.009) mainly due to Periplaneta americana (34.0% vs 12.7%, p=0.0007 respectively) and Canis familiaris (20.0% vs 8.7%, p=0.029). CONCLUSION Although sensitisation to aeroallergens was high among non-asthmatic adolescents, asthma was associated with parental history of atopic disease and sensitisation to P. americana and Canis familiaris but not to D. pteronyssinus showing that local studies are mandatory for the tailoring of appropriate management of allergic diseases.

Assessing caries, dental plaque and salivary flow in asthmatic adolescents using inhaled corticosteroids.

BACKGROUND A number of studies have reported that inhaled corticosteroids may cause a greater incidence of caries, reduced salivary flow, changes in saliva composition and an increased frequency of dental plaque, probably through alterations in the oral microbiota. The objective was to compare the frequency of caries, dental plaque and non-stimulated salivary flow rate among asthmatic adolescents using inhaled corticosteroids and non-asthmatic adolescents, as well as the salivary biochemical parameters (pH and leucocytes) in both groups. METHODS This research has a descriptive cross-sectional design to compare dental health of 40 asthmatics on inhaled corticosteroids and 40 non-asthmatic adolescents (median age 13 years). RESULTS The findings were a higher number of tooth surfaces affected by dental caries (median 4 versus 1.5), and more dental plaques (median 70.5 versus 60.7) among asthmatic adolescents. They also had a significantly higher frequency of salivary leucocytes. The non-stimulated salivary flow was similar in both groups. CONCLUSIONS The results suggest an association between the use of inhaled corticosteroids and an increased risk of dental caries and bacterial plaque, which calls for special attention of these patients by doctors and dental health professionals.

Benzalkonium chloride and nasal mucociliary clearance: a randomized, placebo-controlled, crossover, double-blind trial.

Background Benzalkonium chloride (BKC) has been considered an innocuous preservative for prescription drugs. Methods We performed a double-blind, placebo-controlled, randomized, crossover, single-center trial with a 3-week washout period in 43 healthy volunteers comparing the effect of 3-week use of saline nasal spray containing BKC 0.01% to preservative-free saline t.i.d. on nasal mucociliary clearance rate. Evaluations were done at the beginning and the end of each period by γ-scintigraphy with technetium99m-labeled strontium. Results Nasal mucociliary clearance rate was significantly impaired by BKC with a difference of 1.23 mm·min-1 (p < 0.01) between periods. Conclusion BKC in the concentration used in nasal preparations impaired mucociliary clearance in healthy individuals after 3 weeks of use. Presently, when preservative-free alternatives are available, BKC could be a risk without benefit.

Ascaris lumbricoides infection in urban schoolchildren: Specific IgE and IL-10 production ,

BACKGROUND Helminth infections and allergies are diseases with intense Th2 lymphocytes participation and characterised by a high IgE and Interleukin-(IL) IL-4, IL-5 production and eosinophilia. However, helminths also induce IL-10 production, which may alter the outcome of allergic diseases in infected patients. OBJECTIVE This experimental study analyses the relationship between IL-10 production by cell culture from geohelminth infected and non-infected children and specific IgE to Ascaris lumbricoides (Asc) or Blomia tropicalis (BT). METHODS IL-10 content in supernatant from peripheral blood mononuclear cell culture from nine helminth infected and eleven non-infected patients was determined by ELISA after in vitro stimulation with Asc or BT extracts. RESULTS A positive association was observed between total IgE levels and anti-Ascaris and anti-Blomia tropicalis specific IgE, independent of infection status. For both helminth-infected and non-infected groups, there was no difference in IL-10 production in response to Asc extract, even though anti-Ascaris IgE levels were higher in the latter group. In response to BT stimulus, a lower production of IL-10 by the geohelminth-infected group was observed, but with no relationship between IL-10 production and specific IgE to BT. CONCLUSION The results suggest that anti-Ascaris IgE in non-infected patients may be associated to a resistance to parasites. Levels of specific IgE to parasite antigens or B. tropicalis allergen were not impaired by IL-10 production in children from an urban area in which geohelminthiasis is endemic.

Treatment of wheezing in Brazilian infants in the first year of life

To the Editor, Wheezing disorders in infants are a significant global public health problem, with high morbidity (1), and are responsible for overuse of health resources. The first year of life is when the majority of wheezing infants present their first wheezing episode (2). However, it is difficult to distinguish the different wheezing phenotypes in this age group, such as post-viral wheezing and asthma, which delays the use of appropriate treatment. Asthma-like symptoms are particularly common in the first years of life but represent heterogenic diseases, with little to differentiate the clinical presentations. This heterogeneity is the main problem in both research and daily clinical practice and results in inappropriate treatments in young children (3). The Estudio Internacional de Sibilancias en Lactentes (EISL), or International Study of Wheezing in Infants, held in Latin America, the Netherlands, and Spain, was developed in order to study the impact of wheezing in infants in the first year of life and to identify its prevalence and associated risk factors (1). Parents of infants aged between 12 and 15 months, who attended health centers for routine visits or immunization, answered the validated written questionnaire (WQ)(4) on demographic characteristics, respiratory symptoms (including wheezing), use of medications, medical diagnosis, and possible risk factors for wheezing in the first year of life, such as gender; history of previous respiratory infections; parents or siblings with asthma, rhinitis, or eczema; daycare attendance; exposure to tobacco smoke; presence of pets, carpet, or mold at home; skin allergies; breastfeeding; consumption of processed food. In Brazil, seven centers participated in this study, and the prevalence of wheezing ranged from 43 to 63.6% and recurrent wheezing (three or more episodes in the first year of life) ranged from 21.9 to 36.3% between them (1). The aim of this study was to evaluate the use of drugs for the treatment of occasional and recurrent wheezing among Brazilian centers of EISL.

Investigation of the positivity profile for the skin prick test in children infected with parasites in the metropolitan region of Pernambuco, Northeast of Brazil.

Methods Children between 2 and 14 year old were submitted to a parasitological survey using the Hoffman, Pons e Janer (3 blades) method and the Kato-Katz (2 blades) method. The ISAAC questionnaire was applied to collect informations related to asthma. The Skin Prick Test was applied using extracts of Dermatophagoides pteronyssinus (DP), Blomia tropicalis (BT), Blatella germânica (BG), Periplaneta americana (PA), fungus and cat epithelium (EPC).

Risk factors for recurrent wheezing in infants: a case-control study

ABSTRACT OBJECTIVE To evaluate the association between recurrent wheezing and atopy, the Asthma Predictive Index, exposure to risk factors, and total serum IgE levels as potential factors to predict recurrent wheezing. METHODS A case-control study with infants aged 6-24 months treated at a specialized outpatient clinic from November 2011 to March 2013. Evaluations included sensitivity to inhalant and food antigens, positive Asthma Predictive Index, and other risk factors for recurrent wheezing (smoking during pregnancy, presence of indoor smoke, viral infections, and total serum IgE levels). RESULTS We evaluated 113 children: 65 infants with recurrent wheezing (63.0% male) with a mean age of 14.8 (SD = 5.2) months and 48 healthy infants (44.0% male) with a mean age of 15.2 (SD = 5.1) months. In the multiple analysis model, antigen sensitivity (OR = 12.45; 95%CI 1.28–19.11), positive Asthma Predictive Index (OR = 5.57; 95%CI 2.23–7.96), and exposure to environmental smoke (OR = 2.63; 95%CI 1.09–6.30) remained as risk factors for wheezing. Eosinophilia ≥ 4.0% e total IgE ≥ 100 UI/mL were more prevalent in the wheezing group, but failed to remain in the model. Smoking during pregnancy was identified in a small number of mothers, and secondhand smoke at home was higher in the control group. CONCLUSIONS Presence of atopy, positive Asthma Predictive Index and exposure to environmental smoke are associated to recurrent wheezing. Identifying these factors enables the adoption of preventive measures, especially for children susceptible to persistent wheezing and future asthma onset.