The 'clinically significant' bronchodilator responsiveness (BDR) in children: a comparative study between six definitions of scholarly societies and a mini-review.

Objective: To compare the percentages of children with and without airway obstruction (obstructive and non-obstructive groups, respectively) presenting a 'clinically significant' BDR according to the following definitions: GINA: FEV1 increase >12% predicted (∆Predicted), ATS/ERS: FEV1 increase ≥12% initial (∆Initial) and ∆FEV1 absolute (∆) ≥200 ml and/or ∆FVCInitial ≥12% and ∆FVC ≥200 ml, British thoracic society (BTS): ∆FEV1Initial ≥12%, National asthma education and prevention program (NAEPP): ∆FEV1Initial ≥12% and ∆FEV1 > 200 ml, Group of research on advances in pediatric pneumology: ∆FEV1Initial ≥12% or ∆PEFInitial ≥20%, and South African thoracic society (SATS): ∆FEV1Initial ≥12% or ∆FEV1 >200 ml and/or ∆FVCInitial ≥12% or ∆FVC >200 ml.Methods: This was a multicenter comparative study involving 278 children aged 6 to16 years: obstructive group (FEV1/FVC < lower-limit-of-normal, n = 116) and non-obstructive group (FEV1/FVC ≥ lower-limit-of-normal, n = 162). Spirometry was performed before/after a bronchodilator test. The Cochrane Q test was used to compare the percentage of responders according to the six definitions.Results: The percentages of responders among the obstructive [ranging from 51.72 (NAEPP) to 74.14% (SATS)] and the non-obstructive [ranging from 0.62 (NAEPP, BTS) to 8.64% (SATS)] groups were definition-dependent.Conclusion: In children, a 'clinically significant' BDR is definition-dependent.

Plethysmographic data and profile of North-African patients with severe obstructive sleep apnea treated with continuous positive airway pressure.

OBJECTIVES: In obstructive sleep apnea (OSA) patients, the frequencies of the different ventilatory defects are unknown and the studies examining their plethysmographic profiles and/or pulmonary function test data have contradictory results. The main aim of this prospective study was to establish the plethysmographic profile of severe OSA patients treated with continuous positive airway pressure (CPAP). METHODS: 100 (33 females) clinically consecutive stable patients with severe OSA treated with CPAP were included. Anthropometric, polysomnographic, and pulmonary function test data were collected. The following definitions were applied: large airways obstructive ventilatory defect (LAOVD): (FEV1/SVC or FEV1/FVC < lower limit of normal (LLN), small airways obstructive ventilatory defect (SAOVD): (FEV1/FVC and FVC) > LLN and maximal mid-expiratory flow (MMEF) < LLN, restrictive ventilatory defect (RVD): total lung capacity (TLC) < LLN, lung-hyperinflation: residual volume > upper limit of-normal, and nonspecific ventilatory defect (NSVD): (FVC and FEV1) < LLN and TLC > LLN and (FEV1/SVC or FEV1/FVC) > LLN. RESULTS: The plethysmographic profile of OSA patients included RVD (73%), SAOVD (50%), LAOVD (16%), mixed-VD (11%), lung-hyperinflation (11%), and NSVD (2%). CONCLUSION: The plethysmographic profile of OSA patients was dominated by the presence of an RVD.

[Association between HLA-class II genes and asthma susceptibility in a selected Constantine population]. / L'association entre les gènes HLA II et la susceptibilité à l'asthme chez une population constantinoise sélectionnée.

INTRODUCTION: asthma is a complex disease caused by the interaction of several genes. Some of them have a protective effect and some others contribute to disease onset. This study focuses on a region of the short arm of chromosome 6, where the genes encoding the major histocompatibility complex called HLA are located. This short arm plays an important role in the pathogenesis of asthma. METHODS: our study included 61 subjects, 30 non-asthmatic, non-allergic subjects and 31 patients with more than a 2-year history of allergic asthma. Atopic asthma was confirmed by skin tests and HLA-typing of class II which were performed following the principle of the serological technique of separation by FluoroBeads B. RESULTS: statistical analysis showed that HLA - DR11 and DQ2 genes were significantly more frequent in the asthmatic group compared to the control. The results were as follows: HLA-DR11 with p=0.05 and HLA-DQ2 with p=0.002. Based on this results HLA markers could be associated with asthma. On the other hand HLA-DQ6 marker was substantially higher in the control group than in the asthmatic subjects with p=0.003. CONCLUSION: HLA DR11 and DQ2 markers could be potential markers of susceptibility to asthma, while HLA-DQ6 may have a protective effect.

The multi-ethnic global lung initiative 2012 (GLI-2012) norms reflect contemporary adult's Algerian spirometry.

BACKGROUND: The validation of the multi-ethnic GLI-2012 spirometric norms has been debated in several countries. However, its applicability in Algeria has not been verified. AIM: To ascertain how well the GLI-2012 norms fit contemporary adult Algerian spirometric data. METHODS: This was a cross-sectional study of a convenience sample of 300 healthy non-smoker adults (50% men, age range: 18-85 years) recruited from the Algiers region general population. All participants underwent a clinical examination and a plethysmography measurement. Z-scores for some spirometric data [FEV1, FVC, FEV1/FVC and forced expiratory flow at 25-75% of FVC (FEF25-75%)] were calculated. If the average Z-score deviated by "< ± 0.5" from the overall mean, the GLI-2012 norms would be considered as reflective of contemporary Algerian spirometry. RESULTS: The means±SDs of age, height, weight, FVC, FEV1, FEV1/FVC and FEF25-75% of the participants were, respectively, 48±17 years, 1.65±0.10 m, 73±14 kg, 4.04±1.04 L, 3.18±0.82 L, 0.79±0.05 and 4.09±1.09 L/s. Almost the quarter of participants were obese. The total sample means±SDs Z-scores were 0.22±0.87 for FVC, 0.04±0.88 for FEV1, -0.34±0.67 for FEV1/FVC and 0.93±0.79 for FEF25-75%. For men and women, only the means±SDs of the FEF25-75% Z-scores exceeded the threshold of "± 0.5", respectively, 1.13±0.77 and 0.73±0.76. CONCLUSION: Results of the present study, performed in an Algerian population of healthy non-smoking adults, supported the applicability of the GLI-2012 norms to interpret FEV1, FVC and FEV1/FVC but not the FEF25-75%.

Spirometric reference values for children living in Constantine (Eastern region of Algeria).

BACKGROUND: Spirometry play an important role in diagnosing obstructive lung disease, assessing the severity of lung disease, monitoring treatment of patients with respiratory disorders, and allocating patients to treatment groups in drug intervention studies. Since spirometric lung function depends on body size, age, gender and ethnic group, reference equations derived from healthy individuals are imperative for interpreting results. AIM: To assess the need for spirometric norms for children 5 to 16 years old and living in Constantine (Eastern region of Algeria). METHODS: Anthropometric and spirometric data were measured in 208 healthy children (101 girls) living in Constantine (649 m above sea level). RESULTS: Published reference equations did not reliably predict measured spirometric data in Constantinian children. Combination of gender, age, height, weight, body mass index and body surface area explained between 69% and 94% of the spirometric data variability's. FEV1/FVC ratio [means±SD (5th percentiles) were0.91±0.06 (0.80) for boys and 0.90±0.06 (0.81) for girls] was not included in the regression because of its relative independence of anthropometric data. The mean±SD of the forced expiratory time was 2.44±0.74 s and only 27% of children reached the threshold of ³ 3 s. In an additional group of 24 children prospectively studied, the agreement between measured and predicted FEV1 was satisfactory. CONCLUSION: Our reliable spirometric reference equations provide a useful norm for the care of paediatric patients living in the Eastern region of Algeria. The present study enriches the World Bank of reference equations, from which physicians should choose according to where patients live and their ethnic background.