Clinical characteristics of children and adolescents with severe therapy-resistant asthma in Brazil

Childhood severe asthma: relationship among asthma control scores, FeNO, spirometry and impulse oscillometry

INTRODUCTION

The evaluation of the asthmatic patient is usually based on clinical and functional parameters that do not necessarily evidence the degree of airway inflammation. The aim of this study was to analyze whether clinical scores (CS) correlate with spirometry (S), impulse oscillometry (IO) and FeNO, in severe asthmatic children.

MATERIAL AND METHODS

A multicentric, prospective, cross-sectional study was conducted over a 12-month period. All SA patients (6-18 years old) followed-up in the Pulmonology Department were recruited. CS, FeNO measurements, IO and S were consecutively performed on the same day. Asthma control was ascertained using ACT and GINAq. A cut-off value of ≥ 25 parts per billion (ppb) was used to define airway inflammation.

RESULTS

Eighty-one patients were included. ACT: 75% (n 61) were controlled; GINAq: 44.5% (n 36) were controlled; 39.5% (n 32) were partly controlled, and 16% (n 13) were uncontrolled. FeNO had a median value of 24 ppb (IQR 14-41); FeNO ≥ 25 ppb was observed in 49% of patients (n 39). ROC AUC for FeNO vs. ACT was 0.71 (95%CI 0.57-0.86), PPV 0.47, NPV 0.87, SE 0.61, SP 0.80; FeNO vs. GINAq was ROC AUC 0.69 (95%CI 0.54-0.85), PPV 0.34, NPV 0.91, SE 0.62, SP 0.77; Youden cut-off FeNO > 39 ppb for both CS.

CONCLUSION

In severe asthmatic children, current symptoms control as evidenced by ACT and GINA correlates with low FeNO values. Clinical scores showed good correlation with airway inflammation.

Asthma control in Brazil: a systematic review

Objectives: To explore asthma control in patients undergoing pharmacotherapy on studies in the last 20 years in Brazil. Asthma is a chronic airway inflammation disease with a high prevalence worldwide. Even with a variety of drug treatment improvements, attaining asthma control is challenging, since it should have a personalized approach. In Brazil, studies on the prevalence of asthma control are scarce and usually from a small sample size.Data Sources: A systematic review was performed to assess asthma control in Brazilian population. Terms related to "asthma", "asthma control" and "Brazil" were used in the search strategies in PubMed, BVSalud, Embase and Cochrane Library, including Brazilian Journal of Allergy and Immunology as data sources. A narrative synthesis was performed to report key outcome.Study Selections: In total, 23 studies were included. Most of them were conducted in the Southeastern and Northeast regions, in a short duration.Results: Pediatric and non-pediatric population were assessed, with a higher proportion of female. In pediatric population, those with poorly controlled asthma usually had severe or persistent disease. In elderly, an increased asthma severity was found, although proper treatment might be effective. Most studies (70%) also described exacerbations, hospitalizations (48%), quality of life (39%), and emergency visits (30%). Despite heterogeneity of outcomes and population, studies show an important prevalence of uncontrolled asthma even in patients being treated, with better disease control with treatment improvements.Conclusions: Studies in Brazil have shown that asthma control remains a challenge and there is still a need for improvement on disease management.

Frequência de alterações espirométricas, aprisionamento aéreo e hiperinsuflação pulmonar em crianças e adolescentes com asma grave resistente à terapia

Objetivos: avaliar a frequência de alterações espirométricas e pletismográficas em crianças e adolescentes com asma grave resistente à terapia (AGRT). Além disso, testaram-se possíveis associações entre esses desfechos.Métodos: trata-se de um estudo retrospectivo, no qual foram incluídas crianças e adolescentes (6-18 anos), com diagnóstico de AGRT, e que se encontravam em acompanhamento ambulatorial regular. Todos deveriam possuir informações antropométricas (peso, altura, índice de massa corporal), demográficas (idade, etnia e sexo), clínicas (teste cutâneo, teste de controle da asma, tabagismo familiar e medicações em uso) e de função pulmonar (espirometria e pletismografia corporal) registradas no banco de dados do serviço. Os testes de função pulmonar seguiram as recomendações das diretrizes nacionais e internacionais. Para fins estatísticos, utilizou-se análise descritiva e o teste de qui-quadrado de Pearson.Resultados: de um total de 15 pacientes com AGRT, 12 deles foram incluídos na amostra. A média de idade foi de 12,2 anos, com predomínio do sexo feminino (66,7%). Destes, 50,0% apresentaram a doença controlada, 83,3% foram considerados atópicos e 50,0% tinham histórico de tabagismo familiar. Em relação aos testes de função pulmonar (% do previsto), as médias dos parâmetros espirométricos e de plestismografia corporal encontraram-se dentro dos limites inferiores da normalidade. Apenas 16,7% da amostra apresentou espirometria alterada (<percentil 5), 25,0% aprisionamento aéreo (volume residual>130,0%) e 16,7% hiperinsuflação pulmonar (capacidade pulmonar total>120,0%). Houve frequência estatisticamente maior (p=0,045) de aprisionamento aéreo nos participantes com espirometria alterada, em comparação à espirometria normal. Contudo, não se observou diferença (p=0,341) em relação à hiperinsuflação pulmonar.Conclusões: os achados demonstraram pouco comprometimento espirométrico e dos volumes e das capacidades pulmonares em crianças e adolescentes com AGRT. Além disso, aqueles participantes com espirometria alterada obtiveram frequência maior de aprisionamento aéreo no exame de pletismografia corporal.

Determinants of exercise capacity in children and adolescents with severe therapy-resistant asthma

OBJECTIVE

To evaluate the exercise capacity of children and adolescents with severe therapy resistant asthma (STRA) aiming to identify its main determinants.

METHODS

Cross-sectional study including individuals aged 6-18 years with a diagnosis of STRA. Clinical (age and gender), anthropometric (weight, height and body mass index) and disease control data were collected. Lung function (spirometry), cardiopulmonary exercise testing (CPET) and exercise-induced bronchoconstriction (EIB) test were performed.

RESULTS

Twenty-four patients aged 11.5 ± 2.6 years were included. The mean forced expiratory volume in one second (FEV₁) was 91.3 ± 9.2%. EIB occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO_2peak) was 34.1 ± 7.8 mL kg^-1 min^-1. A significant correlation between ventilatory reserve and FEV₁ (r = 0.57; p = 0.003) was found. Similarly, there was a significant correlation between CPET and percent of FEV₁ fall in the EIB test for both V_E/VO₂ (r = 0.47; p = 0.02) and V_E/VCO₂ (r = 0.46; p = 0.02). Patients with FEV₁<80% had lower ventilatory reserve (p = 0.009). In addition, resting heart rate correlated with VO_2peak (r=-0.40; p = 0.04), V_E/VO₂ (r = 0.46; p = 0.02) and V_E/VCO₂ (r = 0.48; p = 0.01).

CONCLUSIONS

Exercise capacity is impaired in approximately 30% of children and adolescents with STRA. The results indicate that different aspects of aerobic fitness are influenced by distinct determinants, including lung function and EIB.

PEDIATRIC ASTHMA: IMPACT OF THE DISEASE IN CHILDREN RECEIVING OUTPATIENT TREATMENT IN SOUTHERN BRAZIL

OBJECTIVE

To evaluate the impact of pediatric asthma on patients of a specialized outpatient clinic in Southern Brazil.

METHODS

The study included children aged 8 to 17 years old with asthma diagnosis (mild, moderate and severe) under treatment at the asthma clinic of Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil. Measurements of spirometry, quality of life, disease control and atopy tests were applied.

RESULTS

A total of 66 children were included in the study and divided into groups, according to the severity of the disease: mild, moderate or severe asthma. The results showed similarities in both the treatment and the impact of asthma between groups, except for adherence to treatment: the group with mild asthma showed least adherence to treatment, and the group with severe asthma, greater adherence (p=0.011). As to school absenteeism, the group with severe asthma showed higher frequency (p=0.012), with over 10 days per year (p=0.043). Spirometry showed lower volume/capacity for the group with moderate asthma, followed by the groups with severe and mild asthma. All groups had a high prevalence of allergic asthma, with mites as the main allergens. For quality of life (QOL), and health-related quality of life (HRQOL) levels, there were no differences between groups. In addition, the values were close to the acceptable levels for the total score and for each one of the six domains. The same occurred for the HRQOL-asthma module.

CONCLUSIONS

QOL and HRQOL present acceptable levels regardless of the severity of the disease.

Modified Shuttle Test Distance Correlates With Peak Oxygen Uptake in Children and Adolescents With Severe Therapy-Resistant Asthma

Introduction

Several tests may be used to assess exercise intolerance in severe therapy-resistant asthma (STRA), including the gold standard cardiopulmonary exercise test (CPET) and the modified shuttle test (MST).

Objective

To correlate the distance achieved in the MST with peak oxygen uptake (VO₂peak) and to compare the maximal heart rate (HRmax) obtained in both tests in children and adolescents with STRA.

Methods

This is a cross-sectional study, with 19 children and adolescents with STRA. Demographic, anthropometric, clinical data, and spirometric values were collected. CPET and the MST were performed in two consecutive visits. HRmax, pulse oxygen saturation, and dyspnea were compared between tests. The distance achieved in the MST was correlated with VO₂peak.

Results

Nineteen patients with a mean age of 11.5 ± 2.5 years were included. The mean HRmax (bpm) achieved was 180.8 ± 12.10 for the MST and 187.6 ± 9.35 for CPET, whereas the mean HRmax as a percentage of predicted (HRmax%) was 90.7 ± 6.5 for the MST and 93.8 ± 4.5 for CPET. A difference of only 6 bpm was found for HRmax (p = 0.10) and of 3% for HRmax% (p = 0.06) between tests. A strong correlation was found between the MST (r = 0.79; p = 0.001) and VO₂peak measured through CPET. However, there were no correlations between the MST and both body mass index (r = -0.14; p = 0.564) and forced expiratory volume in the first second - FEV₁ (r = -0.02; p = 0.917).

Conclusion

The results demonstrate that the MST distance strongly correlates with VO₂peak, measured through CPET, and the main physiological variable responses were similar between both tests. Our results provide additional data for the use of the MST to assess exercise capacity in children and adolescents with STRA.

Can inflammatory markers in induced sputum be used to detect phenotypes and endotypes of pediatric severe therapy-resistant asthma?

BACKGROUND

The phenotypes and endotypes of severe therapy-resistant asthma (STRA) have not been fully elucidated in children. The aim of the present study was to investigate inflammatory markers in the induced sputum of children with STRA and to compare them with those present in a group of children who achieved control.

METHODS

A prospective cohort of children (6-18 years of age) diagnosed with severe asthma (GINA criteria) who had undergone treatment for at least 6 months was comprehensively followed for 3 months. Inhalation technique, adherence to treatment, ACT score, and main comorbidities were assessed. Induced sputum samples were collected for cytology analysis and quantitative assessment of cytokines; the participants also underwent spirometry, plethysmography, and fractional exhaled nitric oxide (FeNO) measurement.

RESULTS

Forty patients were included (average age 12.8 years; 62.5% male); of these, 13 (32.5%) were classified as STRA at the end of follow-up. There were no significant differences between the STRA and control groups in demographic data, functional test results, or FeNO levels. The eosinophilic inflammatory pattern predominated in both groups; however, the STRA group showed a proportionally higher percentage of sputum neutrophils (P < 0.05). The median sputum levels of the cytokines IL-10, GM-CSF, IFN-γ, and TNF-α were significantly higher in the STRA group (P < 0.05). GM-CSF and TNF-α levels showed inverse correlations with ACT scores.

CONCLUSION

The presence of neutrophils, the cytokines IL-10, and IFN-γ and, more particularly, TNF-α, and GM-CSF in the sputum may play an important role in the pathophysiological mechanism of STRA in children and adolescents. Specific antagonists for these cytokines may represent a future therapeutic strategy.

Association between KIR genes and dust mite sensitization in a Brazilian population

BACKGROUND

Killer cell immunoglobulin-like receptors (KIRs), found on the surface of natural killer (NK) cells, play a key role in controlling the innate response. Such response depends on a series of cellular interactions between these receptors and HLA activating/inhibiting ligands. Atopic diseases have been associated with genes that regulate cytokine production and HLA genes, which may either protect or predispose to hypersensitivity.

OBJECTIVE

To verify an association study of KIR genes with sensitization to the following mites: Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Blomia tropicalis.

METHODS

A total of 341 children aged up to 14 years, were classified as mite-sensitive or mite-insensitive after undergoing a skin prick test for immediate allergic reactions. The presence/absence of KIR genes and their human leukocyte antigen (HLA) ligands was determined by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) with the commercial kit LabType™ using Luminex™.

RESULTS

The frequencies of KIR genes and their respective class I HLA ligands and the frequency of haplotypes were performed in sensitive and insensitive individuals, and no significant differences were found.

CONCLUSION

Our results suggest no influence of KIR genes on resistance/susceptibility to sensitization to dust mites.

Impact of omalizumab in children from a middle-income country with severe therapy-resistant asthma: A real-life study

BACKGROUND

Severe asthma in children is a global health problem. Severe therapy-resistant asthma (STRA) in children is a major clinical challenge due to persistent symptoms despite high doses of corticosteroids and results in high public health costs. Omalizumab (anti-IgE monoclonal antibody) has been described as an effective add-on therapy in these patients. The characteristics of children with STRA from low- and middle-income countries have scarcely been reported, and no real-life study has been published on the effects of omalizumab in this group of patients. The aim of our study is to report the first clinical real-life experiences with omalizumab in Brazilian children with STRA.

METHODS

Children (6-18 years old) from a referral center who were diagnosed with STRA were included in this retrospective study based on our clinical databases. The included children had undergone at least 6 months of omalizumab treatment and fulfilled the following initial criteria: 1) >6 years old; 2) a positive skin-prick test for at least one aeroallergen; and 3) a serum total IgE level between 30 and 1500 IU/mL. Clinical and lung function variables were analyzed before and after treatment.

RESULTS

Fourteen children (mean age: 11.9 years; percentage female: 72%) were included in this study. Omalizumab treatment significantly increased control of the disease according to a standardized questionnaire administered at every visit (P < 0.0001), ceased hospitalizations in 70% (P = 0.02) of patients, and allowed 8/9 (89%) patients to be weaned off oral steroids (P = 0.004).

CONCLUSIONS

In this retrospective report, the use of omalizumab in Brazilian children with STRA significantly improved disease control, decreased hospitalizations, and allowed suspension of continuous oral corticosteroids.

Presence of sarcopenia in asthma-COPD overlap syndrome may be a risk factor for decreased bone-mineral density, unlike asthma: Korean National Health and Nutrition Examination Survey (KNHANES) IV and V (2008-2011)

Background

Sarcopenia and decreased bone-mineral density (BMD) are common in elderly people, and are major comorbidities of obstructive airway disease (OAD). However, the relationship between sarcopenia and BMD in each OAD phenotype, especially asthma–COPD overlap syndrome (ACOS), is not yet clear. We aimed to evaluate differences in BMD according to the presence of sarcopenia in each OAD phenotype.

Materials and methods

Among the research subjects in KNHANES IV and V (2008–2011), 5,562 were ≥50 years old and underwent qualified spirometry and dual-energy X-ray absorptiometry. A total of 947 subjects were included in the study: 89 had asthma, 748 COPD, and 110 ACOS.

Results

In the COPD and ACOS phenotypes, T-scores were lower in the sarcopenia group than the nonsarcopenia group. Prevalence rates of osteopenia and osteoporosis were higher in the sarcopenia group than the nonsarcopenia group. (P<0.001 and P=0.017, respectively). The sarcopenia group had higher risks of developing osteopenia, osteoporosis, and low BMD than the nonsarcopenia group in the ACOS phenotype (OR 6.620, 95% CI 1.129–38.828 [P=0.036], OR 9.611, 95% CI 1.133–81.544 [P=0.038], and OR 6.935, 95% CI 1.194–40.272 [P=0.031], respectively). However, in the asthma phenotype, the sarcopenia group showed no increased risk compared with the nonsarcopenia group.

Conclusion

In the ACOS phenotype, individuals with sarcopenia had a higher prevalence rate and higher risks of osteopenia and osteoporosis than those without sarcopenia among all OAD phenotypes.

Inspiratory muscle function in asthmatic and healthy subjects: influence of age, nutrition and physical activity

OBJECTIVE

To compare inspiratory muscle function (strength and endurance) between asthmatics and healthy controls, and the influence of age, nutritional status and physical activity on them.

METHODS

This is a cross-sectional study. Asthmatic and healthy subjects, aged 6 to 18 years old, recruited from two public schools in Southern Brazil were included in the study. Asthmatic subjects were selected using the criteria presented by the International Study on Asthma and Allergies in Children and control subjects based on the absence of respiratory symptoms. Anthropometric data was measured, body mass index calculated and subjects classified as normal weight, overweight or obese. Physical activity levels, maximum inspiratory pressure (MIP) and inspiratory muscle endurance (IME) were also evaluated.

RESULTS

A total of 314 participants were included, separated into control group (181) and asthmatics (133), with a total mean age of 11 years. When both groups were compared, there were no significant differences in both MIP and IME. However, when groups were analyzed subdivided in children and adolescents, IME was significantly reduced (p = 0.003) in asthmatic adolescents. Indeed, when groups were also stratified considering the nutritional status, IME showed a reduction in asthmatic adolescents with overweight (p = 0.042) and obesity (p = 0.041) when compared to healthy controls. No effects of physical activity levels between groups were found.

CONCLUSIONS

Results demonstrate a reduction in the IME in asthmatic adolescents with overweight and obesity, indicating an association between asthma, nutritional status and respiratory muscle function.