Asthma and other allergic conditions in Colombia: a study in 6 cities

Study of the Direct Costs of Asthma at a Healthcare Service Provider in Bogotá, Colombia

OBJECTIVES

This study aimed to describe clinical characteristics and direct medical costs associated with disease treatment in Colombia patients with asthma from 1 healthcare provider.

METHODS

This was a descriptive study with a retrospective data collection from a healthcare provider's electronic medical records in Colombia. A clinical, demographic, and healthcare resource utilization profile was developed over a 12-month observation period after the identification of eligible patients. To determine the mean cost per patient per year, the total frequencies of resource utilization were added, and the result was multiplied by the unit cost of each of them.

RESULTS

A total of 7919 patients were included in the analysis. The mean ± SD cost per patient per year ranged from $189.5 ± $1.900.6 to $240.2 ± $1.903.6 depending on the price guidebook. The total cost had been driven by the medication use (79% of total cost) and by the outpatient visits (20% of total cost).

CONCLUSIONS

In the population analyzed, the mean total direct cost per patient per year of asthma was $189.5 and $240.2, depending on the cost source. Direct medical costs were higher in cases classified as severe and in the adult and elderly population. When comparing the sources of resource utilization, it was found that the mean cost per patient obtained from real-life data is lower than the theoretical cost obtained from the bottom-up method with quantification of resources from experts. It is important to consider limitations related to study design and the evolving landscape of asthma treatments.

Association between fractional exhaled nitric oxide and therapeutic adherence to controller management in pediatric asthma patients

OBJECTIVES

Guidelines for asthma management recommend, before establishing additional therapeutic behaviors, to confirm correct use and adequate therapeutic adherence to treatment. Evidence exists on the use of fractional exhaled nitric oxide (FeNO) values for monitoring therapeutic adherence in adults. It is important to establish whether there is a correlation between FeNO and therapeutic adherence in children. This study aims to provide new knowledge about the relationship between FeNO and therapeutic adherence in asthmatic children.

MATERIALS AND METHODS

Analytical cross-sectional study including asthma patients 5-18 years of age, attending follow-up at Hospital Militar Central (HMC) between May and November 2022 in Colombia. A sociodemographic survey was carried out, followed by the Pediatric Inhaler Adherence Questionnaire (PIAQ), and asthma control test (ACT) or childhood asthma control test (cACT). We defined adequate therapeutic adherence as not missing a single application of inhaled steroids in the last 15 days according to PIAQ. A poisson regression model was carried out including relevant predictors for therapeutic adherence such as FeNO values, age, tobacco exposure at home, atopy, and time since initiation of use of inhaled controller.

RESULTS

Eighty-two children with a median age of 10 years (interquartile range: 7-12 years) were included. Adequate therapeutic adherence was reported by 68.3%. After adjusting for age, sex, exposure to cigarette smoke, duration of controller therapy, and atopy, FeNO < 20 ppb was independently associated with adequate therapeutic adherence (RR = 1.5, p = .04, 95% confidence interval: 1.03-2.19).

CONCLUSIONS

FeNO values seem to be useful to identify pediatric patients with asthma who have adequate adherence to inhaled steroids in a MIC.

Comparison of three alternatives for the management of moderate asthma in children aged 6-11 years: a cost-utility analysis

BACKGROUND

Recent asthma guidelines for children 6-11 years with persistent asthma advocate three alternatives: SMART (budesonide/formoterol 80/4.5 mcg qd plus additional doses as needed), fixed combination of budesonide/formoterol, and fixed-dose budesonide. Concerns have arisen as to which of the proposed alternatives has the best possible cost-effectiveness profile. This study aimed to assess the health and economic consequences of SMART, fixed combination, and fixed-dose budesonide therapy in children 6-11 years old with persistent asthma.

METHODS

A probabilistic Markov model was created to estimate the cost and quality-adjusted life-years (QALYs) of patients with persistent asthma. Total costs and QALYs of SMART, fixed combination, and fixed-dose budesonide therapy were calculated over a time horizon of 6 years. Multiple sensitivity analyses were conducted.

RESULTS

The mean QALY per patient was 0.57 and 0.56 QALYs per patient per year of SMART and fixed combination and 0,52 with fixed-dose budesonide. The total mean of discounted costs per patient per cycle were US$111 for SMART, US$133 for fixed combination, and US$67 for fixed-dose budesonide. The net monetary benefit of SMART was US$12,549, US$12278 for fixed combination, and US$11,380 for fixed-dose budesonide.

CONCLUSION

Our study showed that SMART was more cost-effective than fixed combination and fixed-dose budesonide. These findings complement and support the GINA 2021 and National Asthma Education and Prevention Program asthma guideline recommendations for use of inhaled corticosteroids-formoterol in children 6-11 years old with persistent asthma.

Efficacy and safety of subcutaneous immunotherapy with a mixture of glutaraldehyde-modified extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae , and Blomia tropicalis

Background

Allergen Immunotherapy (AIT) is an effective treatment of allergic respiratory diseases induced by the inhalation of house dust mite allergens.

Objectives

To evaluate the efficacy and safety of glutaraldehyde polymerized allergen extracts using a mixture of Dermatophagoides pteronyssinus, D. farinae and Blomia tropicalis in mite allergic individuals residing in Colombia.

Methods

Two hundred and fifty (250) patients with allergic rhinoconjunctivitis with, or without asthma and sensitized to D. pteronyssinus, D. farinae and B. tropicalis were included. A glutaraldehyde-modified extract containing a mixture of D. pteronyssinus, D. farinae and B. tropicalis was employed, using a cluster up-dosing schedule followed by a monthly maintenance dose. The primary endpoints to evaluate the clinical impact were the Combined Symptom and Medication Scores (CSMS) for allergic rhinitis, the Asthma Control Test (ACT) and the reduction in medication consumption.

Results

Significant improvement was found after 3 months of treatment regarding CSMS (p < 0.0001) and ACT (p < 0.0001). Additionally, a significant decrease in medication consumption was found after 3 months of treatment (p < 0.0001). Adverse reactions, either local or systemic were mild and no severe reactions related to the vaccines were observed.

Conclusion

After 12 months of allergen immunotherapy, glutaraldehyde-modified mixture of D. pteronyssinus, D. farinae and B. tropicalis proved to be safe and effective in the treatment of patients with rhinoconjunctivitis with or without asthma due to allergy to mites.

Clinical and sociodemographic features and quality of life in patients with atopic dermatitis who attended dermatology teaching clinics in Medellín, Antioquia and its metropolitan area

Introduction: Atopic dermatitis is a cutaneous, inflammatory, chronic disease, very frequent in the world and it imposes a high clinical and quality of life impact in patients. To date there are no local studies describing the general features in our population. Objective: To evaluate the socio demographic, clinical and life quality features in patients with atopic dermatitis from Medellín city and its metropolitan area. Materials and methods: cross sectional, descriptive study, that included patients who attended some teaching dermatological clinics. Data collection included sociodemographic and clinical features in addition to clinical issues and quality of life measurements. Results: A total of 13 patients were included. 36,3% manifested a sleeping disturbance, 38,1% attention deficit; 44,2% reported asthma in the childhood. EASI and SCORAD scores were 6,9 and 32,4, respectively, which indicates a mild-moderate compromise. Regarding quality of Life, Skindex-29 showed average scores for the symptomatic, emotional and functional dominions of 37,7, 25,09 and 16,9, respectively, and a total score of 24,78. In EQ-5D scores, the most altered component was the presence of pain or discomfort (17,6%) and the presence of anxiety or depression (12,1%), which enhances the symptomatic and emotional impact of the disease. Conclusion: These results confirm that patients with atopic dermatitis present similar features to those reported in other studies from different countries, highlighting the burden of the disease in adults and its impact in neuropsychiatric and emotional domains.

Impact of the allergen-specific immunotherapy in pediatric patients with asthma treated at a health institution in Colombia

Introduction: Asthma is a chronic and potentially serious disease and 80% of the cases have an allergic etiology. In this sense, allergen-specific immunotherapy is an alternative that modulates the natural course of the disease. Objective: To evaluate the impact of immunotherapy in pediatric asthma patients treated at a health institution in Colombia. Materials and methods: We conducted an observational descriptive study with an analytical cross-sectional component. Sixty-two patients diagnosed with allergic asthma sensitized to dust mites and treated with at least 6 doses of mite immunotherapy were included. We assessed the impact of immunotherapy using the Asthma Control Test (ACT), the Global Initiative for Asthma (GINA) treatment scale, and spirometry values. Results: The ACT score before the start reported 30% of patients with uncontrolled asthma, 28% with good control, and 4% with totally controlled asthma. Of the patients with uncontrolled asthma, 46.7% achieved good control and 23.3% total control. Regarding patients’ perception of improvement with the immunotherapy, 9.75% perceived a response of less than 50%, 45.2% one between 50% -90%, and 41.9% reported response equal to or greater than 90%. No significant changes in FEV1 values were found in spirometry. Conclusions: Significant changes in the ACT scores and the perception of disease improvement were observed in the population evaluated with specific mite immunotherapy, i.e., it had a positive impact on the natural course of the disease.

Nasal Obstruction and Quality of Life Assessment After Septoplasty With Turbinoplasty: Correlation Between Subjective Scales

BACKGROUND

Assessment of nasal obstruction is imprecise due to a low correlation between findings on the physical examination and objective measures with the severity of symptoms reported by the patient even after septoplasty with turbinoplasty is performed. The aim of this study is to evaluate the use of subjective scales, and the correlation between them for the evaluation of nasal obstruction after surgery.

OBJECTIVE

To assess the impact of undergoing septoplasty with turbinoplasty to relieve nasal obstructive symptoms and the quality of life in a mid-term period by using the Visual Analogue Scale (VAS), Nasal Obstruction Symptom Evaluation (NOSE), and Glasgow Benefit Inventory (GBI).

METHODS

A retrospective study was conducted of patients who underwent a septoplasty with turbinoplasty due to nasal septodeviation and secondary nasal obstructive symptoms at the Hospital Universitario Fundación Santa Fe de Bogotá. Three scales were used to measure the outcomes one year after surgery: VAS (0-10), NOSE (0-100), and GBI (-100 to 100).

RESULTS

Data from 56 patients (21 females, mean age 37.5 years of age, SD 12.13) was collected. The results showed that 75% of the patients had a post-surgical NOSE score below 50 and a VAS score below 6. Regarding the GBI scale, 75% of the patients improved in their quality of life. An inverse proportional correlation was found between the NOSE and GBI scales (rho = -0.3682) (95% CI -0.579 to -0.111), and there was a directly proportional correlation between the NOSE and VAS scales (rho = 0.7440) (95% CI 0.595 to 0.844).

CONCLUSION

Subjective measures suggest there was an improvement in nasal obstructive symptoms and quality of life after surgery. Non-anatomical causes such as rhinitis can be confounding factors to consider in subsequent studies. VAS stands out as a possible interchangeable scale with NOSE to measure nasal obstruction in these patients.

Prevalence of skin diseases in children 1 to 6 years old in the city of Bogota, Colombia

BACKGROUND

Skin diseases represent an important part of the morbidity among children and are possibly influenced by geographic, racial, social, cultural, and economic factors. Despite being so frequent around the world, skin diseases have not been important in developing strategies in public health.

AIM

The purpose of this study was to evaluate the prevalence of skin diseases among the student population between 1 and 6 years of age in Bogotá, Colombia between March 2009 and June 2011.

MATERIALS AND METHODS

This cross-sectional study was performed across a probabilistic, stratified, randomized sampling by proportional assignment (based on locality and type of institution) and was developed in schools in Bogotá, Colombia.

RESULTS

A total of 2437 children between 1 and 6 years of age were examined, and 42.8% (1035) presented a dermatologic disease. Papular urticaria was the most frequent (62.9%) (IC: 58.4%; 67.1%), followed by dermatitis/eczema (13.0%) (IC: 10.8%; 15.4%), and infectious diseases (12.3%) (IC: 9.7%; 15.3%).

CONCLUSION

The research demonstrates a high prevalence of papular urticaria as a result of flea and mosquito bites and infectious diseases of the skin in the studied population. The dermatologic diseases found are easy to diagnose, respond to the proper treatment, and are preventable. However, the fact that many of the examined children likely had not visited the doctor for the detected pathology could indicate the lack of access to health services affecting this population.

Asia-Pacific Survey of Physicians on Asthma and Allergic Rhinitis (ASPAIR): physician beliefs and practices about diagnosis, assessment, and treatment of coexistent disease

Background

Asthma and allergic rhinitis (AR) frequently coexist, and having both asthma and AR is associated with uncontrolled asthma and a heavier disease burden. The Asia-Pacific Survey of Physicians on Asthma and Allergic Rhinitis (ASPAIR) aimed to assess physicians’ perceptions and their management practices for patients with coexistent disease.

Materials and methods

A total of 1,204 general physicians and pediatricians from six countries in Asia, who routinely treat asthma patients, were interviewed in-person. Physicians were questioned about their attitudes and beliefs of coexistent asthma-AR, how they diagnose and treat patients, and their knowledge of international guideline recommendations.

Results

Physicians reported that 45% of their patients with asthma have coexistent AR and 37% of their patients with AR have coexistent asthma. Most physicians (77%) agreed that coexistent asthma-AR is a genuine condition and that patients suffer worse symptoms with both the conditions vs one alone (86%). Although nearly all agreed that both asthma and AR should be treated (91%) and that intranasal (INS) and inhaled corticosteroids (ICS) could be given concurrently to these patients, 40% also thought that treating both conditions effectively at the same time is difficult, and approximately a quarter believed that corticosteroid therapy should be delayed in children for both asthma and AR. While there was universal recognition and acceptance that guidelines provide sufficient information for treating uncontrolled coexistent disease (≥80% physicians in all countries), physicians revealed that 41% of their asthma patients are treated with short-acting rescue medications alone, and only 47% responded that treatment with concurrent INS and ICS, as recommended in the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines, was their preferred treatment for coexistent disease.

Conclusion

The ASPAIR survey demonstrates a widespread acceptance of coexistent asthma-AR, and the associated burden, but highlights the need for increased healthcare practitioner communication and awareness to improve appropriate treatment and management of these coexistent conditions.

Health care costs and resource utilization for different asthma severity stages in Colombia: a claims data analysis

BACKGROUND

Asthma is one of the most common chronic respiratory conditions worldwide. Asthma-related economic burden has been reported in Latin America, but knowledge about its economic impact to the Colombian health care system and the influence of disease severity is lacking. This study estimated direct medical costs and health care resource utilization (HCRU) in patients with asthma according to severity in Colombia.

METHODS

This study identified all-age patients who had at least one medical event linked to an asthma diagnosis (CIE-10: J45-J46) between 2004 and 2014. Patients were selected if they had a continuous enrollment and uninterrupted insurance coverage between January 1-2015 and December 31-2015 and were categorized into 4 different severity levels using a modified algorithm based on Leidy criteria. Healthcare utilization and costs were estimated in a 1-year period after the identification period. A Generalized Linear Model (GLM) with gamma distribution and log link was used to analyze costs adjusting for patient demographics.

RESULTS

A total of 20,410 patients were included: 69.5% had mild intermittent, 18.0% mild persistent, 6.9% moderate persistent and 5.5% severe persistent asthma; with mean costs (SD) of $67 (134), $482 (1506), $1061 (1983), $2235 (3426) respectively (p < 0.001). The mean total direct cost was estimated at $331 (1278) per patient. Medication and hospitalization had the higher proportion in total costs (46% and 31% respectively). General physician visits was the most used service (57.2%) and short-acting β-2 agonists the most used medication (24%).

CONCLUSIONS

Health services utilization and direct costs of asthma were highly related to disease severity. Nationwide health policies aimed at the effective control of asthma are necessary and would play an important role in reducing the associated economic impact.

Ascariasis as a model to study the helminth/allergy relationships

Ascariasis is the most frequent soil transmitted helminthiasis and, as well as other helminth infections, is expected to influence the clinical presentation of allergic diseases such as asthma. Indeed, several clinical and experimental works have shown an important impact either increasing or suppressing symptoms, and the same effects have been detected on the underlying immune responses. In this review we analyze the work on this field performed in Colombia, a Latin American tropical country, including aspects such as the molecular genetics of the IgE response to Ascaris; the allergenic activity of Ascaris IgE-binding molecular components and the immunological and clinical influences of ascariasis on asthma. The analysis allows us to conclude that the impact of ascariasis on the inception and evolution of allergic diseases such as asthma deserves more investigation, but advances have been made during the last years. The concurrent parasite-induced immunostimulatory and immunosuppressive effects during this helminthiasis do modify the natural history of asthma and some aspects of the practice of allergology in the tropics. Theoretically it can also influence the epidemiological trends of allergic diseases either by its absence or presence in different regions and countries.

Adherence to pharmacotherapy improves school performance in children with rhinitis and asthma

BACKGROUND

Adherence to pharmacotherapy reduces symptoms of asthma and rhinitis, however, little is known of its impact on school performance.

OBJECTIVE

To evaluate the impact of pharmacotherapy in absenteeism and school performance in a child population.

METHODS

A cross-sectional study, carried out in eight schools. All participants and their parents were given a questionnaire assessing parameters related to respiratory diseases and pharmacotherapy. Data on school performance was obtained from the academic history of each child who participated in the study. Adherence to pharmacotherapy was classified as a correct use of therapy for more than five days per week.

RESULTS

1109 children agreed to participate. Students were divided into two groups: symptomatic (36%) and asymptomatic (63%). The symptomatic group had a higher frequency of school absenteeism (1 vs. 3.1days/year/patient p<0.01) and lower academic performance (failed: 20% vs. 33% p<0.01). After dividing the symptomatic group between adherents and non-adherents to the pharmacotherapy, the group of adherents had a similar school performance to the asymptomatic group and it was significantly different from the no-adherent group.

CONCLUSION

Respiratory symptoms are associated with poor school performance and with an increase in school absenteeism, but adherence to pharmacotherapy can reduce these negative impacts in children.

Nanogold - IgY antibodies. An immunoconjugated for the detection of house dust mite (Dermatophagoides) allergens

Conjugation of avian IgY antibodies to nanosensors has been extensively explored for the diagnostics of virus and parasite infection, as well as for the detection of pharmaceutically and toxicologically relevant molecules. However, to date this strategy has only been minimally applied the detection of allergens. In this study, gold nanoparticles (GNPs) were conjugated to a polyvalent IgY antibodies raised against Dermatophagoides group I allergens. GNPs were synthesized by HAuCL₄ reduction using 1% trisodium citrate, and characterized them by absorption spectroscopy and transmission electron microscopy (TEM). The most stable immunoconjugates were obtained with 18-nm monodisperse GNPs and a minimal concentration of 12.5 μg/mL of IgY at pH 7.5. The immunoconjugate was capable of detecting up to 1.5 μg of a total Dermatophagoides farinae protein extract in an immuno-dot blot assay. This immunoreactant conjugate represents a new tool for the detection and control of indoor dust mite allergens.

Clinical differences between children with asthma and rhinitis in rural and urban areas

BACKGROUND

Epidemiological studies have shown that children who grow up on traditional farms are protected from allergic diseases. However, less is known about if the environment influences the pharmacotherapy in these patients.

OBJECTIVE

To compare the treatment of asthmatic and rhinitis children from urban and rural areas in Medellín, Colombia.

METHODS

During one year, we follow up a group of children (6 to 14 years) with diagnostic of asthma or rhinitis living for more than five years in urban or rural area. A questionnaire with socio-demographic characteristics, pharmacotherapy treatments, was obtained each three months. Atopy evaluation, spirometry and clinical test for asthma and rhinitis severity were done at the beginning and one year later.

RESULTS

Eighty six point four percent patients completed the follow up (rural n: 134, urban n: 248). Patients in rural location required less salbutamol (p: 0.01), visit to emergency department (p <0.01) and have a less number of patients with FEV1 <80% (p: 0.05). For clinical control rural children require less pharmacotherapy than urban children (p: 0.01) and more patients with rhinitis (18% vs 8% p: 0.03) and asthma (23% vs 12% p: 0.01) in the rural group could suspended pharmacotherapy. Atopy (p: <0.07) and poli-sensitization (p: <0.08) was a little higher in urban than rural area. We observe that poverty/unhygienic indicators were risk factors for higher levels of specific IgE among patients from urban area.

CONCLUSION

Patients with respiratory allergies located in urban area require more pharmacotherapy and have less clinical response than rural children.

Gut microbiota components are associated with fixed airway obstruction in asthmatic patients living in the tropics

Microbiome composition has been associated to several inflammatory diseases, including asthma. There are few studies exploring the relationships of gut microbiota with airway obstruction pheonotypes in adult asthma, especially those living in the tropics. We sought to evaluate the relationships of gut microbiota with the airway obstruction and other variables of interest in asthmatic patients living in the tropics according to three phenotypes: No Airway Obstruction (NAO), Reversible Airway Obstruction (RAO) or Fixed Airway Obstruction (FAO). We found that Streptococcaceae:Streptococcus and Enterobacteriaceae:Escherichia-Shigella consistently discriminated asthmatic individuals suffering FAO from NAO or RAO, plus Veillonellaceae:Megasphaera when comparing FAO and RAO (p < 0.05; FDR < 0.05). In the FAO, the network showing the genus relations was less complex and interconnected. Several Rumminococcaceae, Lachnospiraceae and Clostridiales were enriched in patients with low specific IgE levels to mites and Ascaris. All patients shared a common exposure framework; control medication usage and smoking habit were uncommon and equally distributed between them. In conclusion, in this tropical asthmatic population, components of human gut microbiota are associated with the presence of a FAO phenotype and lower specific IgE response to mites and Ascaris.

Sex-Related Allergic Rhinitis Prevalence Switch from Childhood to Adulthood: A Systematic Review and Meta-Analysis

BACKGROUND

A sex-related switch in the prevalence of asthma from childhood (male predominance) to adulthood (female predominance) has been described, but for allergic rhinitis this remains unclear. We aimed to examine sex- and age-group-specific differences in allergic rhinitis prevalence by systematically evaluating studies from across the globe.

METHODS

A systematic search of MEDLINE and Embase for population-based cross-sectional studies was performed regardless of the language of publication. The search was restricted to the present millennium (2000 to June 2014). Study quality was defined by the sampling method, response rate, sample size, and data collection method. To assess sex differences in the prevalence of self- or parent-reported symptoms of rhinitis, calculated pooled estimates of the male-female ratio (MFR) were obtained using random-effects model meta-analyses due to heterogeneity. A meta-regression analysis was also performed.

RESULTS

Out of 6,539 publications identified, 67 cross-sectional population-based studies (291,726 males and 301,781 females) were included in our meta-analysis. In children (<11 years of age) significantly more boys than girls had rhinitis symptoms (MFR 1.21, 95% CI 1.17-1.25), whereas in adolescents (11 to <18 years of age) males were significantly less often affected than females (MFR 0.90, 95% CI 0.85-0.95). No sex-specific prevalence difference was observed in adults (MFR 0.96, 95% CI 0.83-1.17). These findings were consistent in all continents except in Asia, where the male predominance remained beyond childhood.

CONCLUSIONS

The male predominance of rhinitis prevalence in childhood changed towards a female predominance in adolescence across the globe, except in Asia. Longitudinal studies are needed to confirm these cross-sectional data and examine possible determinants and underlying mechanisms.

[Allergen immunotherapy: Mechanisms of action, and therapeutic and socioeconomic impact Consensus of the Asociación Colombiana de Alergia, Asma e Imunología]

Allergies comprise a set of highly prevalent diseases. When allergic processes are not controlled, they can endanger patients' health and lives, and have an important economic and social impact. The aim of this paper is to present a practical consensus of the scientific evidence on the use of immunotherapy in allergic diseases. A collaborative review made by various institutes and universities in Colombia was carried out upon request of the Asociación Colombiana de Alergia, Asma e Imunología, led by general practitioners, allergists, immunologists, internists and paediatricians with experience in the field of allergies. As a result, based on current national and international scientific evidence, we describe in detail what immunotherapy is about, its indications, contraindications and its economic and health benefits. Conclusions show immunotherapy as a clinically effective and safe treatment, which can substantially reduce the cost of the overall treatment of allergic patients.

Particularities of allergy in the Tropics

Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

Modulación de la respuesta alérgica por los carotenoides de la dieta

<p>Los carotenoides son pigmentos isoprenoides que están presentes de manera natural y en altas concentraciones en la mayoría de alimentos vegetales —entre ellos, aguacate, papaya, tomate y zanahoria—, pero también encontrados como aditivos y colorantes en diversos productos cárnicos, aceites vegetales, salsas, aderezos, harinas, entre otros. En los últimos años, algunos estudios han descrito que los carotenoides de la dieta participan en varios procesos fisiopatológicos, incluyendo la respuesta inmune de tipo alérgico. Las tasas de prevalencia para este tipo de enfermedades han incrementado de manera alarmante durante las últimas cinco décadas en todo el mundo, a la vez que varios factores e hipótesis se han planteado tratando de explicar este fenómeno: uno de ellos es la hipótesis de la dieta, la cual plantea que la composición de varios micro y macronutrientes de la alimentación, así como los cambios en los patrones dietarios, influirían en tal problemática. Evidencia epidemiológica y básica experimental emergente señala que los carotenoides de la dieta participan en la regulación de la inflamación alérgica, y por ello se postulan como coadyuvantes en la terapia de tales padecimientos. En el presente artículo se revisará el estado del arte en relación a los efectos de los carotenoides de la dieta sobre la patología alérgica.</p>

IgE responses to Ascaris and mite tropomyosins are risk factors for asthma

BACKGROUND

The relationship between helminthiases and allergy is a matter of considerable interest and research. In the tropics, house dust mite exposure, a known risk factor for asthma, is frequently concurrent with helminth infections. It remains to be defined whether infection with the common roundworm Ascaris or its bystander immunological effects influence the prevalence and pathogenesis of asthma independently of mite sensitization.

OBJECTIVE

To investigate the relationship between the IgE responses to Ascaris and its purified allergens and the risk of asthma in a tropical country.

METHODS

A nested case-control study was performed in 356 subjects who reported current and past asthma symptoms (asthmatics) and 435 controls that had never experienced such symptoms. They were tested for serum levels of total IgE and specific IgE to Ascaris extract, Asc s 1 (ABA-1), Asc l 3 (tropomyosin) and GST (glutathione transferase). In addition, specific IgE to Dermatophagoides pteronyssinus, Blomia tropicalis and their tropomyosins Der p 10 and Blo t 10 was measured. Sensitization was defined as a positive specific IgE result to any extract or recombinant allergen.

RESULTS

Sensitization to Ascaris and D. pteronyssinus was independently associated with asthma after adjustment for age, gender, socio-economic stratum, city and other IgE levels (adjusted ORs: 2.17; 95% CI 1.37-3.42 and 2.46; 95% CI 1.54-3.92), respectively. There was also a significant association with sensitization to the highly allergenic and cross-reactive tropomyosins Asc l 3, Blo t 10 and Der p10 (aORs: 1.76; 95% CI 1.21-2.57, 1.64; 95% CI 1.14-2.35 and 1.51; 95% CI 1.02-2.24), respectively.

CONCLUSION AND CLINICAL RELEVANCE

IgE responses to Ascaris are associated with asthma symptoms in a population living in the tropics. Sensitization to the cross-reactive Ascaris and mite tropomyosins partially underlies this finding. These results have potential relevance in asthma diagnosis and management.

Virus and Mycoplasma pneumoniae prevalence in a selected pediatric population with acute asthma exacerbation

OBJECTIVE

To determine the prevalence of viral and atypical bacteria Mycoplasma pneumoniae infection in children experiencing asthma exacerbation and compare positive and negative subjects with regard to exacerbation severity, need for hospitalization, and treatment.

METHODS

One hundred sixty-nine asthmatic children aged 2-15 years old who were admitted to emergency rooms in Bogota, Colombia for acute asthma exacerbation were interviewed. Nasopharyngeal aspirates were taken for DNA and RNA extraction. M. pneumoniae and virus were detected by PCR using specific primers.

RESULTS

The prevalence of M. pneumoniae and viral infection in the study population was 12.4% and 83.7%, respectively. All subjects positive for M. pneumoniae were also positive for viral infection. Rhinovirus was the most frequently detected viral agent. No significant differences in severity of asthma exacerbations or in need for hospitalization between the virus or M. pneumoniae positive and negative groups were observed. A significantly lower percentage of M. pneumoniae positive subjects had used inhaled steroids over the six months prior to asthma exacerbation compared to M. pneumoniae negative subjects (38.1% vs. 68.2%), suggesting that inhaled corticosteroids may have a protective effect against M. pneumoniae infections.

CONCLUSIONS

The M. pneumoniae and virus prevalence found in this study were similar to those described in the literature. The 100% co-infection rate observed suggests that viral infection can predispose patients to M. pneumoniae infection, and that this interaction may trigger asthmatic exacerbation. Further studies should be done to confirm the protective effect of inhaled corticosteroids on M. pneumoniae infection in patients with asthma exacerbations.

Prevalence, risk factors and underdiagnosis of asthma and wheezing in adults 40 years and older: A population-based study

OBJECTIVE

There are differences in the prevalence and risk factors of asthma around the world. The epidemiological situation of adults 40 years and older is not well established. Our aim was to determine the prevalence, underdiagnosis and risk factors of asthma and wheezing in adults in Colombia.

METHODS

A cross-sectional, population-based study including 5539 subjects from 40 to 93 years selected by a probabilistic sampling technique in five cities was conducted.

MEASUREMENTS

respiratory symptoms and risk factors questionnaire and spirometry.

DEFINITIONS

(a) Wheezing: Affirmative answer to the question "have you ever had two or more attacks of "wheezes" causing you to feel short of breath?" (b) Asthma: Wheezing definition and FEV1/FVC post-bronchodilator ≥ 70%. (c) Underdiagnosis: Asthma definition without a physician-diagnosis. Logistic regression was used for exploring risk factors.

RESULTS

Prevalence of asthma was 9.0% (95% CI: 8.3-9.8) and wheezing 11.9% (95% CI: 11.0-12.8). Asthma underdiagnosis was 69.9% and increased to 79.0% in subjects 64 years or older. The risk factors related to asthma and/or wheezing were: living in Bogota or Medellin, female gender, first degree relative with asthma, respiratory disease before 16 years of age, obesity, no education, indoor wood smoke exposure and occupational exposure to dust particles, gases or fumes.

CONCLUSION

We described the epidemiologic situation of asthma in adults 40 years and older in Colombia. In addition to some recognized risk factors, our data supports the association of indoor wood smoke and occupational exposures with asthma and wheezing. Underdiagnosis of asthma in adults was high, particularly in older subjects.

The IgE response to Ascaris molecular components is associated with clinical indicators of asthma severity

Background

Asthma is a common chronic disease worldwide and Ascaris lumbricoides infection (ascariasis) is frequent in tropical regions. However, the effect of ascariasis on asthma severity has not been sufficiently explored. We sought to evaluate the influence of the IgE immune response to Ascaris extract and purified house dust mites (HDM) and Ascaris allergens on indicators of asthma severity in patients living in the tropics.

Methods

Asthmatic patients from Cartagena, Colombia were recruited. Clinical assessment included questionnaires, physical examination, allergy skin tests, spirometry, parasite stool examination and IgE antibody measurements. Asthma was diagnosed by a physician according to validated criteria. Indicators of severity were occurrence of severe dyspnea episodes, night awakenings events, > 4 emergency room (ER) visits and hospitalizations during the last year. Specific IgE to Der p 2, Ascaris spp., Blomia tropicalis and Dermatophagoides pteronyssinus extracts was determined by ImmunoCap. IgE to tropomyosins (Asc l 3, Blo t 10 and Der p 10), Blo t 5 and Asc s 1 was detected by ELISA. Logistic regression analyses were used to explore the relationships between sensitization and indicators of asthma severity.

Results

After adjustment for HDM sensitization, Ascaris sensitization remained associated with severe dyspnea (aOR: 1.90, 95% CI: 1.08 - 3.34, p = 0.03) and > 4 ER visits (aOR: 2.23, 95% CI: 1.15 - 4.30, p = 0.02). We also found that sensitization to the species specific markers Blo t 5 and Asc s 1, as well as the cross-reactive tropomyosins of D. pteronyssinus and Ascaris were associated with > 4 ER visits. Der p 2 sensitization was associated with bronchodilator responsiveness (aOR: 2.24: 1.25-4.02, p = 0.01). Remarkably, significantly higher IgE levels to HDM species specific allergens were found in Ascaris sensitized patients.

Conclusions

In this tropical population, IgE sensitization to Ascaris and the cross-reactive tropomyosins was frequent and associated with clinical indicators of asthma severity. The significant relationship between sensitization to the nematode-specific marker Asc s 1 and ER attendance supports these findings. Moreover, ascariasis increases the human IgE responses to HDM specific allergens.

Early life IgE responses in children living in the tropics: a prospective analysis

BACKGROUND

There are few birth cohort studies analyzing IgE sensitization in the tropics.

OBJECTIVES

We aimed to describe the evolution of total IgE and specific IgE responses to house-dust mite (HDM) allergens and Ascaris in a birth cohort (Risk Factors for Asthma and Allergy in the Tropics, FRAAT), analyzing their relationships with wheezing.

METHODS

Total and specific IgE were measured by ImmunoCap in mothers and children at four different time points (S1-S4) between 0 and 42 months. Parasite infection was evaluated by stool examination.

RESULTS

Maternal total IgE (aOR: 2.43, 95% CI: 1.09-5.43; p = 0.03) and socio-demographic factors were associated with high cord blood (CB) total IgE. High CB total IgE was positively associated with higher Blomia tropicalis and Ascaris-specific IgE values during lifetime, but protected from recurrent wheezing (aOR: 0.26, 95% CI: 0.08-0.88, p = 0.03). Prevalence rates of IgE sensitization were high; at around 3 yr old, they were 33.3, 18.6, and 26.5% for B. tropicalis, Dermatophagoides pteronyssinus, and Ascaris, respectively. Indicators of unhygienic conditions were risk factors for HDM and Ascaris sensitization in children. A weak statistical association between B. tropicalis-specific IgE and ever wheezing was found (aOR: 1.47 95% CI: 1.00-2.28, p = 0.05).

CONCLUSIONS

In a socioeconomically deprived community from the tropics, sensitization to HDM allergens was very frequent at early life, especially to B. tropicalis. In contrast to expected according to the hygiene hypothesis, unhygienic/poverty conditions were risk factors for allergen sensitization. High CB total IgE levels were a risk factor for allergen sensitization but protected from recurrent wheezing.

New Allergens of Relevance in Tropical Regions: The Impact of Ascaris lumbricoides Infections

One of the many aspects of the relationships between parasite infections and allergic diseases is the possibility that allergens from parasites enhance the T_H2 responses, especially IgE production, in allergic diseases such as asthma. In this review we discuss about the allergenic composition of the nematode Ascaris lumbricoides and their potential impact on allergy sensitization and asthma pathogenesis and prevalence in populations living in the tropics and naturally exposed to both, mite allergens and helminth infections.

Health-related quality of life in children and adults with respiratory allergy in Colombia: prospective study

BACKGROUND

Allergic diseases are very common, with the estimated cumulative prevalence in Colombia for asthma and allergic rhinitis being 22.7% and 31.3% respectively, and with a clear upward trend. A major social as well as economic impact associated with allergic disease has been described. Because in Colombia there are no studies that assess the Health-Related Quality of Life (HRQOL) in allergic respiratory diseases, our aim is to describe the HRQOL in subjects with respiratory allergy and its association with clinical control variables.

METHODS

A prospective descriptive study was conducted among 76 Colombian subjects with rhinitis and asthma/allergic rhinitis. In order to evaluate the HRQOL, the instruments Kidscreen-27 and SF-36 were applied. The scores obtained in the HRQOL fields were correlated with the following clinical variables: peak expiratory flow (PEF) and peak nasal inspiratory flow (PNIF).

RESULTS

In children, the better HRQL domain is present in the school environment (55.9) and the worst in psychological well-being (39.9). For adults the worst HRQL was found in the emotional function domain (55.6) while the physical function (81.7) had the best. There were no statistical differences between groups of asthma/allergic rhinitis and allergic rhinitis. Subjects with allergic asthma showed a strong correlation between the mental health domain and PEF values (r=-0717, p=0.046).

CONCLUSION

Mental health is more affected than physical health in Colombian subjects with respiratory allergy. There was a strong correlation between the mental health domain and the values of PEF in patients with asthma/allergic rhinitis.

Prevalence of asthma and other allergic conditions in Colombia 2009-2010: a cross-sectional study

Background

While it is suggested that the prevalence of asthma in developed countries may have stabilized, this is not clear in currently developing countries. Current available information for both adults and children simultaneously on the burden and impact of allergic conditions in Colombia and in many Latin American countries is limited. The objectives of this study were to estimate the prevalence for asthma, allergic rhinitis (AR), atopic eczema (AE), and atopy in six colombian cities; to quantify costs to the patient and her/his family; and to determine levels of Immunoglobulin E (IgE) in asthmatic and healthy subjects.

Methods

We conducted a cross-sectional, population-based study in six cities during the academic year 2009–2010. We used a school-based design for subjects between 5–17 years old. We carried out a community-based strategy for subjects between 1–4 years old and adults between 18–59 years old. Serum samples for total and antigen-specific (IgE) levels were collected using a population-based, nested, case–control design.

Results

We obtained information on 5978 subjects. The largest sample of subjects was collected in Bogotá (2392). The current prevalence of asthma symptoms was 12% (95% CI, 10.5-13.7), with 43% (95% CI, 36.3-49.2) reporting having required an emergency department visit or hospitalization in the past 12 months. Physician diagnosed asthma was 7% (95% CI, 6.1-8.0). The current prevalence of AR symptoms was 32% (95% CI, 29.5-33.9), and of AE symptoms was 14% (95% CI, 12.5-15.3). We collected blood samples from 855 subjects; 60.2% of asthmatics and 40.6% of controls could be classified as atopic.

Conclusions

In Colombia, symptom prevalence for asthma, AR and AE, as well as levels of atopy, are substantial. Specifically for asthma, symptom severity and absence from work or study due to symptoms are important. These primary care sensitive conditions remain an unmet public health burden in developing countries such as Colombia.

Rhinoconjunctivitis prevalence and associated factors in school children aged 6-7 and 13-14 years old in Bogota, Colombia

OBJECTIVE

Allergic rhinitis is one of the most frequent chronic diseases among children. The objective of the study was to assess the prevalence of rhinoconjunctivitis and determine clinical, social and environmental associated factors, among school children aged 6-7 years and adolescents aged 13-14 years in Bogotá, Colombia.

METHODS

We used ISAAC (International Study of Asthma and Allergies in Childhood) phase III study methodology and questionnaire for design and data collection, and we did a secondary analysis of these data. The sample consisted of 3830 registers from adolescents between 13 and 14 years old and 3256 registers from children between 6 and 7 years.

RESULTS

The prevalence of rhinoconjunctivitis symptoms in the last year was 17.2% (95% CI, 15.9-18.5) in children vs. 24.9% (95% CI, 23.6-26.3) in adolescents. In both groups there was a female predominance in children (17.8% vs. 16.5%), and in the teenagers group (28.0% vs. 21.4%), though the differences were not statistically significant. The factors associated with rhinoconjunctivitis in the group of 6-7 years where: asthma [OR 3.9; (95% CI, 2.8-5.4)], atopic dermatitis [OR 2.3; (95% CI, 1.7-3.1)], use of acetaminophen in the last year [OR 2.6; (95% CI, 1.4-4.9)], use of antibiotics in the first year of live [OR 1.7; (95% CI, 1.3-2.3)], higher maternal education [OR 1.5; (95% CI, 1.0-2.3)] and cesarean delivery [OR 1.6; (95% CI, 1.2-2.1)]. Among the 13-14 year age-group, factors associated with rhinoconjunctivitis included: asthma [OR 2.6; (95% CI, 2.0-3.4)], atopic dermatitis [OR 1.8; (95% CI, 1.4-2.3)], use of acetaminophen in the last year [OR 1.8; (95% CI, 1.4-2.4)], consumption of fast-food three times or more per week [OR 1.5; (95% CI, 1.2-2.0), ever smoked [OR 1.4; (95% CI, 1.2-1.7)] and meat consumption was protective factor [OR 0.7; (95% CI, 0.5-0.9)].

CONCLUSION

In both studied groups, the estimated prevalence of rhinoconjunctivitis symptoms was relatively high. Future in-depth research is needed to assess the complex interactions between allergic rhinoconjunctivitis symptoms and social and environmental factors.

Influence of poverty and infection on asthma in Latin America

PURPOSE OF REVIEW

Asthma in Latin America is a growing public health problem and seems to be most prevalent and cause most morbidity among poor urban populations. This article will review the findings of recent human studies of the associations of asthma prevalence in Latin America with factors associated with poverty and inequality including childhood infections, stress, environment, nutrition and diet.

RECENT FINDINGS

Most asthma in childhood in Latin America is nonatopic and has been associated with exposures related to environmental dirt, diet and psychosocial distress. These factors are strongly linked to poverty and inequality. Interestingly, infections with bacterial, viral and parasitic pathogens in childhood appear to attenuate atopy in childhood but have no effect on asthma symptoms. There are biologically plausible mechanisms by which dirt exposures (e.g. endotoxin and other microbial products and nonmicrobial irritants), diet and obesity and psychosocial stress may cause airways inflammation.

SUMMARY

Most childhood asthma in Latin America is nonatopic for which important risk factors are those of poverty including poor hygiene (i.e. dirt), poor diet and obesity and psychosocial stress. There is evidence that exposures to infections in early childhood reduce atopy but not asthma. Research is needed to identify causes of nonatopic asthma that may be suitable for primary prevention or other public health intervention strategies for asthma in Latin America.

Particular characteristics of allergic symptoms in tropical environments: follow up to 24 months in the FRAAT birth cohort study

Background

Early wheezing and asthma are relevant health problems in the tropics. Mite sensitization is an important risk factor, but the roles of others, inherent in poverty, are unknown. We designed a birth-cohort study in Cartagena (Colombia) to investigate genetic and environmental risk factors for asthma and atopy, considering as particular features perennial exposure to mites, parasite infections and poor living conditions.

Methods

Pregnant women representative of the low-income suburbs of the city were randomly screened for eligibility at delivery; 326 mother-infant pairs were included at baseline and biological samples were collected from birth to 24 months for immunological testing, molecular genetics and gene expression analysis. Pre and post-natal information was collected using questionnaires.

Results

94% of families were from the poorest communes of the city, 40% lacked sewage and 11% tap-water. Intestinal parasites were found as early as 3 months; by the second year, 37.9% of children have had parasites and 5.22% detectable eggs of Ascaris lumbricoides in stools (Median 3458 epg, IQR 975-9256). The prevalence of "wheezing ever" was 17.5% at 6 months, 31.1% at 12 months and 38.3% at 24 months; and recurrent wheezing (3 or more episodes) 7.1% at 12 months and 14.2% at 24 months. Maternal rhinitis [aOR 3.03 (95%CI 1.60-5.74), p = 0.001] and male gender [aOR 2.09 (95%CI 1.09 - 4.01), p = 0.026], increased risk for wheezing at 6 months. At 24 months, maternal asthma was the main predisposing factor for wheezing [aOR 3.65 (95%CI 1.23-10.8), p = 0.01]. Clinical symptoms of milk/egg allergy or other food-induced allergies were scarce (1.8%) and no case of atopic eczema was observed.

Conclusions

Wheezing is the most frequent phenotype during the first 24 months of life and is strongly associated with maternal asthma. At 24 months, the natural history of allergic symptoms is different to the "atopic march" described in some industrialized countries. This cohort is representative of socially deprived urban areas of underdeveloped tropical countries. The collection of biological samples, data on exposure and defined phenotypes, will contribute to understand the gene/environment interactions leading to allergy inception and evolution.

IgE cross-reactivity between Ascaris lumbricoides and mite allergens: possible influences on allergic sensitization and asthma

Nematode infections such as Ascariasis are important health problems in underdeveloped countries, most of them located in the tropics where environmental conditions also promote the perennial co-exposure to high concentrations of domestic mite allergens. Allergic diseases are common, and most of patients with asthma exhibit a predominant and strong IgE sensitization to mites. It is unknown whether co-exposure to Ascaris lumbricoides and the domestic mites Blomia tropicalis and Dermatophagoides pteronyssinus potentiates Th2 responses and IgE sensitization, thereby modifying the natural history of allergy. Recently, we obtained experimental evidence of a high cross-reactivity between the allergenic extracts of these invertebrates, involving well-known allergens such as tropomyosin and glutathione transferases. There is indirect evidence suggesting that the clinical impact of these findings may be important. In this review, we discuss the potential role of this cross-reactivity on several aspects of allergy in the tropics that have been a focus of a number of investigations, some of them with controversial results.

[Incidence of respiratory symptoms and the association with air pollution in preschoolers: a multilevel analysis]

The aim of this study was to evaluate the association between air pollution and respiratory symptoms in preschoolers from Bucaramanga, Colombia. A cohort study was conducted by reporting daily symptoms in preschoolers living in two zones of the city with different PM10 air pollution levels. Individual and neighborhood variables were included in a multilevel analysis. In 707 preschoolers followed for a year, sneezing and cough with mucus were the most frequent symptoms, with incidence rates of 277.2 and 203.3 events per 100 child months at risk. In the high pollution zone, an increase of 10 microg/m3 in PM10 concentration increased the reporting of daily symptoms by 1.3. Multilevel analysis showed no statistical association between PM10 and respiratory symptoms, but asthma history, heavy traffic in front of the residence, presence of domestic pets, and dirt floors were associated with respiratory symptoms.

Importance of allergic rhinitis management in achieving asthma control: ARIA update

Asthma continues to be a major burden for the health and healthcare of people worldwide. The recent updates of the Global Initiative for Asthma and the National Heart, Lung and Blood Institute asthma guidelines stress the need for achieving and monitoring asthma 'control', emphasizing the importance of identifying, assessing and treating comorbid conditions. Allergic rhinitis (AR) is a major comorbid condition in people with asthma and is related to inflammation of the upper portions of the airway. Recognizing and treating AR has been shown to improve asthma control, specifically by decreasing rates of asthma attacks or asthma exacerbations. In 2008, updated Allergic Rhinitis in Asthma (ARIA) guidelines were published. The updated version of the guidelines has a familiar look, with classification systems and care algorithms that are similar to those presented in other asthma guidelines. The new ARIA guidelines make one major change that should affect the care of adults and children with asthma: everyone with asthma should be assessed for AR. In addition, AR should be considered a risk factor for asthma, and all children and adults with AR, especially persistent AR, should be assessed for asthma, including testing lung function for reversible obstruction whenever feasible. Treatment for AR follows a similar format to that for asthma, including symptom management, treatment of chronic inflammation, identification and management of triggers, including allergens, and ongoing education for self-management. Pharmacotherapies that address both asthma and AR include corticosteroids (intranasal and inhaled), leukotriene receptor antagonists, immunomodulation or immunotherapy. Too often, pharmacotherapy is not supplemented by the necessary education and evaluation related to allergen, trigger identification and management.

A Six-SNP haplotype of ADAM33 is associated with asthma in a population of Cartagena, Colombia

BACKGROUND

A disintegrin and metalloprotein-33 (ADAM33) participates in the bronchial remodeling process in asthma, and genetic analyses pointed it out as a candidate gene in asthma.

METHODS

To analyze the association between ADAM33 and asthma and total and mite-specific IgE levels in a population of the Caribbean Coast of Colombia, we genotyped 6 single-nucleotide polymorphisms of ADAM33 in 429 asthmatics, 401 controls and 116 family trios using fluorogenic probes. Total and specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus were determined by ELISA. Case-control and family-based analyses were performed. Case-control association analyses were corrected by population stratification using a set of 52 ancestry-informative markers.

RESULTS

Eight common haplotypes were identified; among them, H4 (GCAGGG) was associated with asthma in the family group (Z score: -2.049, p = 0.04). We also found an association between the TT genotype of ST+7 and asthma in the case-control study (p = 0.05) that disappeared after correcting for multiple testing. In the family-based analysis, this genotype was a risk factor for asthma (p = 0.01), high total IgE (Z score: 2.546, p = 0.01) and high specific IgE against B. tropicalis (p = 0.02) and D. pteronyssinus (Z score: 2.414, p = 0.01). V4 was associated with specific IgE against B. tropicalis (p = 0.03); T2 with asthma (p = 0.03), high total IgE (p = 0.02) and IgE against D. pteronyssinus (p = 0.03) and T1 with high total IgE (p = 0.04). None of these associations was maintained after correction for multiple testing.

CONCLUSIONS

Our findings suggest a relevant role of ADAM33 in thepathogenesis of asthma in this population.

Association between total immunoglobulin E and antibody responses to naturally acquired Ascaris lumbricoides infection and polymorphisms of immune system-related LIG4, TNFSF13B and IRS2 genes

The 13q33-34 region harbours a susceptibility locus to Ascaris lumbricoides, although the underlying genes are unknown. Immunoglobulin (Ig)E and IgG confer protective immunity and here we sought to investigate in an endemic population whether LIG4, TNFSF13B and IRS2 genes influence IgE and IgG levels against Ascaris and the ABA-1 allergen as a putative resistance marker. Mite-allergic asthmatic patients were analysed for potential relationships between Ascaris predisposition and allergy. One thousand and sixty-four subjects from Cartagena, Colombia, were included. Single nucleotide polymorphisms (SNPs) were genotyped using TaqMan assays. Antibody levels were measured by enzyme-linked immunosorbent assay. Linear and logistic regressions were used to model effects of genotypes on antibody levels. The GG genotype of LIG4 (rs1805388) was associated with higher IgE levels to Ascaris compared with other genotypes. TNFSF13B (rs10508198) was associated positively with IgG levels against Ascaris extract and IgE levels against ABA-1. In asthmatics, IRS2 (rs2289046) was associated with high total IgE levels. Associations held up after correction by population stratification using a set of 52 ancestry markers, age, sex and disease status. There was no association with asthma or mite sensitization. In a tropical population, LIG4 and TNFSF13B polymorphisms are associated with specific IgE and IgG to Ascaris, supporting previous linkage studies implicating the 13q33 region. Our results suggest that genes protecting against parasite infections can be different to those predisposing to asthma and atopy.

Association of G-protein-coupled receptor 154 with asthma and total IgE in a population of the Caribbean coast of Colombia

BACKGROUND

G protein-coupled receptor 154 was described as an asthma susceptibility gene by positional cloning. It has been subsequently associated with asthma and other inflammatory diseases in several populations with different ethnic origin. Replication of associations adds reliability to these findings.

OBJECTIVE

To analyze the association of G protein-coupled receptor 154 with asthma and total and mite-specific IgE levels in a population of the Caribbean Coast of Colombia.

METHODS

We genotyped seven single nucleotide proteins (SNPs) in GPR154 in 475 asthmatics, 394 controls and 116 families from Cartagena, Colombia using either SnaPshot or TaqMan. Total and specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus were determined by ELISA. Hardy-Weinberg equilibrium was assessed and case-control and family-based analyses were performed to evaluate the association between the SNPs and their haplotypes and asthma and IgE. Association analyses in the case-control dataset were corrected by population stratification using 52 ancestry informative markers.

RESULTS

Allelic distribution was similar to that described in other populations. Two SNPs were associated with the same direction of the effect in both datasets. Allele A of Hopo546333 was protective for asthma (case-control OR: 0.42; 95% CI: 0.17-0.99, P=0.042; P=0.043; families Z score=-2,236; P=0.025). Similarly, allele C of rs740347 conferred low risk for asthma (OR: 0.44; 95% CI: 0.28-0.70, P=0.00017; Pc=0.00037) and total IgE (OR: 0.29; 95% CI: 0.09-0.88, P=0.015; Pc=0.030) in the case-control study and families (Z score=-3.207, P=0.0013; Z score=-3.182, P=0.0014, respectively). Haplotype CCAGGT was associated with total IgE (OR: 1.76; 95% CI: 1.14-2.71, P=0.006, Pc=0.007) in the case-controls group and CGCGGT with both phenotypes (P=0.044 and P=0.032, respectively) in families. Neither SNPs nor haplotypes were associated with levels of mite-specific IgE.

CONCLUSIONS

Our findings in a sample of asthmatics from Colombia suggest a relevant role of G protein-coupled receptor 154 in the pathogenesis of asthma and allergy.

Asthma in Latin America: a public heath challenge and research opportunity

Asthma has emerged as an important public health problem in many Latin American countries over the past decade. In Brazil and Costa Rica, the prevalence of asthma and associated morbidity is as great or greater as reported in traditional high prevalence countries such as the US, but remains neglected as a public health priority. Asthma in Latin America is associated particularly with underprivileged populations living in cities but remains relatively rare in many rural populations. The causes of asthma in Latin America are likely to be associated with urbanization, migration, and the adoption of a modern 'Westernized' lifestyle and environmental changes that follow these processes that include changes in diet, physical activity, hygiene, and exposures to allergens, irritants, and outdoor and indoor pollutants. Because of the enormous social, genetic, and environmental contrasts within and between Latin American countries, and the large differences in prevalence associated with these differences, the investigation of asthma in Latin America provides important research opportunities to identify the social and biological mechanisms that underlie asthma development. Asthma in Latin America poses enormous challenges for health policy makers, health services, and researchers to respond to and alleviate the growing burden of asthma disability, particularly among marginalized urban populations.

Prevalence of and factors associated with current asthma symptoms in school children aged 6-7 and 13-14 yr old in Bogotá, Colombia

This cross-sectional study of children aged 6-7 years and adolescents aged 13-14 years in Bogotá, Colombia, assessed the prevalence of asthma symptoms and their associations with dietary, health, and behavioral habits. This study is part of the International Study of Asthma and Allergies in Childhood (ISAAC)-phase III. Asthma prevalence among the children was assessed using a parental self-administered written questionnaire (WQ), and among adolescents using a WQ together with a video questionnaire (VQ). Associations were estimated with bivariate and multivariate analysis. The study found that the 6-7 year age-group were more likely to report current asthma symptoms than the 13-14 year age-group (10.4% [WQ] vs. 8.6% [WQ] and 8.0% [VQ], respectively). Factors associated with current asthma symptoms among the 6-7 year age-group included higher maternal education (OR = 1.7, [95% CI 1.2-2.6], p = 0.007), a cat in the home during the last year (OR = 1.5, [95% CI 1.0-2.3], p = 0.036), watching TV 1-2 hours/day (OR = 2.1, [95% CI 1.2-3.9], p = 0.013), and medication with acetaminophen in the first and most recent year of life (OR = 1.8, [95% CI 1.3-2.4], p < 0.001; OR = 2.2, [95% CI 1.7-2.8], p < 0.001, respectively) or antibiotics in the first year of life (OR = 1.9, [95% CI 1.4-2.5], p < 0.001). Among the 13-14 year age-group, factors associated with current asthma symptoms included medication with acetaminophen during the last year (OR = 1.8, [95% CI 1.4-2.3], p < 0.001); cereal, milk, and fruit consumption 3 or more times weekly (OR = 1.5, [95% CI 1.1-1.9], p = 0.010; OR = 0.8, [95% CI 0.6-1.0], p = 0.046; OR = 0.6, [95% CI 0.4-1.0], p = 0.031, respectively). Overall, compared with that in other Latin American centers, asthma prevalence in Bogotá is close the lower estimates. However, associations with dietary, health, and behavioral habits need further study to assess their complex relationship with asthma.

Immunological characterization of a Blo t 12 isoallergen: identification of immunoglobulin E epitopes

BACKGROUND

Differences in the IgE response to isoallergens could have clinical implications; therefore, its analysis will contribute to the design of better strategies for the diagnosis and treatment of allergic respiratory diseases. Several isoforms have been described from mites but there is no information about the clinical impact of Blomia tropicalis isoallergens.

OBJECTIVE

To evaluate the differences in the IgE response against two Blo t 12 isoallergens.

METHODS

The IgE-binding properties of Blo t 12 isoallergens were analysed by ELISA, a skin prick test and ELISA cross-inhibition. Epitope mapping was performed using synthetic overlapping peptides. Fold recognition methods were used to model the chitin-binding domain of the two isoallergens.

RESULTS

The frequency and strength of the IgE response were greater for Blo t 12.0101 than for Blo t 12.0102. Three IgE-binding areas were identified in Blo t 12.0101; one of them included two residues that are different in Blo t 12.0102. Modelling of the chitin-binding domains of these allergens predicted that they have structural differences that could influence antibody recognition of one of these epitopes.

CONCLUSION

In silico structural analysis and immunological characterization of Blo t 12 reveals that allergen polymorphism influences IgE reactivity. Blo t 12.0101 is the most IgE-reactive isoform in Cartagena. The identified IgE epitopes could be mutated to obtain hypoallergenic molecules of potential use for immunotherapy.

Common characteristics of upper and lower airways in rhinitis and asthma: ARIA update, in collaboration with GA(2)LEN

This update aimed to review the new evidence available to support or refute prior Allergic Rhinitis and its Impact on Asthma (ARIA) statements. A Medline search of publications between 2000 and 2005 was conducted, with articles selected by experts. New evidence supports previous ARIA statements, such as: (i) allergic rhinitis (AR) is a risk factor for asthma; (ii) patients with persistent rhinitis should be evaluated for asthma; (iii) most patients with asthma have rhinitis; (iv) a combined strategy should be used to treat the airways and (v) in low- to middle-income countries, a different strategy may be needed. The increased risk of asthma has also been found among sufferers from non-AR. Recent reports show AR is a global problem. Many studies demonstrated parallel increasing prevalence of asthma and rhinitis, but in regions of highest prevalence, it may be reaching a plateau. Factors associated with a reduced risk of asthma and AR have been identified, confirming previous findings of protection related to exposure to infections. Treatment of rhinitis with intranasal glucocorticosteroids, antihistamines, leukotriene antagonists or immunotherapy may reduce morbidity because of asthma. To take advantage of the paradigm of unified airways, there is a need to rationalize diagnosis and treatment to optimize management.

Distinctive immunoglobulin E anti-house dust allergen-binding specificities in a tropical Australian Aboriginal community

BACKGROUND

There is evidence that the specificity of the IgE binding in allergy tests can vary for different populations.

OBJECTIVE

We aimed to examine the allergenic specificity of IgE binding in sera from house dust mite (HDM)-atopic subjects in a tropical Australian Aboriginal community.

METHODS

Sera shown to contain IgE antibodies to an HDM extract of Dermatophagoides pteronyssinus were examined for IgE binding to a panel of nine purified HDM allergens from this mite species by quantitative microtitre assays. IgG antibody binding (IgG1 and IgG4) was also measured.

RESULTS

The IgE-binding activity in the sera from the Aboriginal community was not directed to the expected major groups 1 and 2 HDM allergens but instead to the group 4 amylase allergen. There was also little IgE binding to the potentially cross-reactive tropomyosin (Der p 10) or arginine kinase (Der p 20) allergens. The IgG4 antibody was rarely detected and limited to the Der p 4 allergen. IgG1 antibody binding was frequently measured to all the allergens regardless of an individual's atopic status, whereas in urban communities it is restricted to the major allergens and to atopic subjects.

CONCLUSION

The high IgE anti-HDM response of Australian Aboriginals predominantly bound Der p 4 and not the Der p 1 and 2 allergens, showing a distinctive allergy that could affect the disease outcome and diagnosis.

A NOS1 gene polymorphism associated with asthma and specific immunoglobulin E response to mite allergens in a Colombian population

BACKGROUND

Nitric oxide (NO) is involved in asthma pathogenesis and is synthesized by three isoforms of NO synthase, one of them encoded by NOS1 gene. The CA-repeat and the C5266T SNP in NOS1 exon 29 have been associated with asthma and IgE levels. We thought to test the association of asthma and asthma-related phenotypes with the exon 29 CA-repeat and the C5266T SNP in a Colombian population sample.

METHODS

The CA-repeat and the C5266T SNP were genotyped in 167 asthmatics and 166 controls using PCR-based fragment length polymorphism and TaqMan assay. We also determined total and mite-specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus.

RESULTS

Three new CA-repeat alleles, 14, 23 and 24 repeats were detected. Allele comprising 16 repeats was associated with asthma (OR: 1.90 (CI 1.22-2.97, p(c) = 0.028) and low total (p(c) = 0.02) and specific IgE to B. tropicalis (p(c) < 0.0001) and D. pteronyssinus (p(c) < 0.0001). We found no association of the C5266T SNP and asthma or IgE levels.

CONCLUSION

NOS1 exon 29 CA-repeat may be a risk factor for asthma susceptibility and mite specific IgE response in a Colombian population.

Asthma hospitalizations in the state of Qatar: an epidemiologic overview

BACKGROUND

An increasing trend in asthma morbidity and mortality has been reported in a number of countries, including New Zealand, Great Britain, France, Italy, the United States, and Asia; however, no previous studies have evaluated the trend in admission and epidemiology of asthma in the state of Qatar.

OBJECTIVE

To describe the patterns of epidemiology of asthma patients who require hospitalization in the state of Qatar.

METHODS

This study is a cross-sectional analysis of discharge data for 2002 from the Hamad General Hospital, State of Qatar, for patients who were hospitalized with a primary diagnosis of asthma.

RESULTS

The asthma hospitalization rate was 42 per 100,000 population. The male-female ratio was 47:53. Of these patients, 35% were younger than 15 years, 60% were between 15 and 64 years, and 5% were 65 years or older. The average cost per admission was dollar 1,544. The mean length of stay was 6.4 days and was longer for females, Qatar nationals, older patients, and those with comorbid conditions. Infectious diseases were common in younger patients, whereas cardiovascular diseases and diabetes were the most common comorbidities in middle-age and elderly asthmatic patients. December was the peak month for hospitalization. The mortality rate was 1.7 per 100,000 population.

CONCLUSIONS

For asthma patients in Qatar, the hospitalization rate is below the recommended Healthy People 2000 goal and the mortality rate is low.

Asthma in Hispanics

Hispanic individuals trace their ancestry to countries that were previously under Spanish rule, including Mexico, large parts of Central and South America, and some Caribbean islands. Most--but not all--Hispanics have variable proportions of European, Amerindian, and African ancestry. Hispanics are diverse with regard to many factors, including racial ancestry, country of origin, area of residence, socioeconomic status, education, and access to health care. Recent findings suggest that there is marked variation in the prevalence, morbidity, and mortality of asthma in Hispanics in the United States and in Hispanic America. The reasons for differences in asthma and asthma morbidity among and within Hispanic subgroups are poorly understood but are likely due to the interaction between yet-unidentified genetic variants and other factors, including environmental tobacco smoke exposure, obesity, allergen exposure, and availability of health care. Barriers to optimal management of asthma in Hispanics in the United States and in Hispanic America include inadequate access to health care, suboptimal use of antiinflammatory medications, and lack of reference values for spirometric measures of lung function in many subgroups (e.g., Puerto Ricans). Future studies of asthma in Hispanics should include large samples of subgroups that are well characterized with regard to self-reported ethnicity, country of origin, place of birth, area of residence, and indicators of socioeconomic status. Because Hispanics are disproportionately represented among the poor in the United States, implementation of adequate access to health care and social reforms (e.g., improving housing conditions) would likely have a major impact on reducing asthma morbidity in this population.