Maternal milk protects infants against bronchiolitis during the first year of life. Results from an Italian cohort of newborns

OBJECTIVE

Bronchiolitis is one of the primary causes of hospitalization in infancy. We evaluated the effect of breastfeeding on the occurrence of hospitalization for bronchiolitis in the first year of life.

METHODS

In a prospective cohort study, 1,814 newborns of =33 weeks of gestational age (wGA) were enrolled in 30 Italian Neonatology Units and followed-up for 1 year to assess hospitalizations for bronchiolitis. Children were grouped as 'never breastfed' and 'ever breastfed'; these latter were further divided into those 'exclusively breastfed' and 'breastfed associated with milk formula'. The risk of hospitalization for bronchiolitis was evaluated with survival analysis, and hazard ratios (HR) with 95% confidence interval [95% CI] were calculated.

RESULTS

Among enrolled newborns 22.9% were 'never breastfed'; in the breastfed group, 65% were 'exclusively breastfed' and 35% were 'breastfed with associated milk formula'. At 12 months of age, the risk of hospitalization for bronchiolitis was significantly higher in the 'never breastfed' group (HR: 1.57; 95% CI: 1.00-2.48). 'Breastfed associated with formula milk' and 'exclusively breastfed' groups were at similar risk of hospitalization for bronchiolitis. This observed protective effect of maternal milk was not explained by the higher prevalence of conditions able to increase the risk of bronchiolitis among 'never breastfed newborns'.

CONCLUSIONS

Breastfeeding, even in association with formula milk, reduces the risk of hospitalization for bronchiolitis during the first year of life. Encouraging breastfeeding might be an effective/inexpensive measure of prevention of lower respiratory tract infections in infancy.

Modulation of airway epithelial cell functions by Pidotimod: NF-kB cytoplasmatic expression and its nuclear translocation are associated with an increased TLR-2 expression

Background

Recurrent respiratory infections are one of the most important causes of morbidity in childhood. When immune functions are still largely immature, the airway epithelium plays a primary defensive role since, besides providing a physical barrier, it is also involved in the innate and the adaptive immune responses. A study was therefore designed to evaluate in vitro whether pidotimod, a synthetic dipeptide able to stimulate the inflammatory and immune effector cells, could activate bronchial epithelial cell functions involved in response to infections.

Methods

BEAS-2B cell line (human bronchial epithelial cells infected with a replication-defective Adenovirus 12-SV40 virus hybrid) were cultured in the presence of pidotimod, with or without tumor necrosis factor (TNF)-α or zymosan to assess: a) intercellular adhesion molecule (ICAM)-1 expression, by flow cytometry; b) toll-like receptor (TLR)-2 expression and production, by immunofluorescence flow cytometry and western blotting; d) interleukin (IL)-8 release, by enzyme-linked immunosorbent assay (ELISA); e) activated extracellular-signal-regulated kinase (ERK1/2) phosphorylation and nuclear factor-kappa B (NF-kB) activation, by western blotting.

Results

The constitutive expression of ICAM-1 and IL-8 release were significant up-regulated by TNF-α (ICAM-1) and by TNF-α and zymosan (IL-8), but not by pidotimod. In contrast, an increased TLR-2 expression was found after exposure to pidotimod 10 and 100 μg/ml (p < 0.05) and to the association pidotimod 100 μg/ml + TNF-α (p < 0.05). Western blot analysis substantiated that the constitutive TLR-2 expression was significantly increased after exposure to all the stimuli. Finally, while a remarkable inhibition of TNF-α -induced ERK1/2 phosphorylation was observed in the presence of pidotimod, both TNF-α and pidotimod were effective in inducing NF-kB protein expression in the cytoplasm and its nuclear translocation.

Conclusion

Through different effects on ERK1/2 and NF-kB, pidotimod was able to increase the expression of TLR-2 proteins, surface molecules involved in the initiation of the innate response to infectious stimuli. The lack of effect on ICAM-1 expression, the receptor for rhinovirus, and on IL-8 release, the potent chemotactic factor for neutrophils (that are already present in sites of infection), may represent protective functions. If confirmed in vivo, these activities may, at least in part, clarify the mechanism of action of this molecule at airway level.

Blood eosinophil counts rarely reflect airway eosinophilia in children with severe asthma

BACKGROUND

The inflammatory phenotypes of severe asthma in adults may be reflected in peripheral blood. If this were true in children with severe therapy-resistant asthma (STRA), invasive tests could be avoided. At the moment there is no conclusive evidence in children.

METHODS

All patients underwent blood tests, exhaled nitric oxide (FeNO), sputum induction, bronchoalveolar lavage (BAL) and endobronchial biopsy (EB).

RESULTS

Sixty-three (71.6%) patients had a normal blood profile and only 1/88 had a combined blood eosinophilia and neutrophilia. 76/88 (86%) had normal blood eosinophils, but of these, 84% had airway eosinophilia in either BAL (n = 43;66%) or EB (n = 41;79%). In children with STRA blood eosinophilia was associated with airway eosinophilia. However, normal blood eosinophil levels did not exclude airway eosinophilic inflammation.

CONCLUSIONS

Peripheral blood counts are not reliable in characterising airway inflammation in severe asthmatic children exposed to high dose steroid therapy, therefore bronchoscopy with BAL should be considered.

Weakly acidic gastroesophageal refluxes are frequently triggers in young children with chronic cough

OBJECTIVE

To evaluate whether the proportion of acid and weakly acidic refluxes preceding cough bursts could be different in infants, preschool- and school-aged children with chronic, unexplained cough.

PATIENTS AND METHODS

One hundred six children with unexplained chronic cough, not receiving acid suppressive therapy, underwent impedance-pH monitoring. They were divided into Group A: <2 years (21 pts), Group B: ≥2 to ≤6 years (41 pts), and Group C: >6 years (44 pts). Reflux was defined as acid (pH <4), weakly acidic (WA; pH 4-7), and weakly alkaline (pH >7).Cough episodes were considered temporally associated with gastroesophageal reflux (GER) when occurring within 2 min after a GER episode.

RESULTS

Impedance-pH detected 55.50 (39.00-76.00) reflux episodes/patient with an acid-to-WA reflux event ratio of 3.31 (1.55-8.33). This parameter was significantly lower in Group A (1.33 [0.41-3.40]) than in Group B (3.06 [2.00-6.50]; P < 0.05] and Group C (5.09 [2.34-12.43; P < 0.001]). No cough episode was preceded by weakly alkaline refluxes in any patient. During impedance-pH recording, 93 patients (87.7%) had at least one cough episode that had been preceded by impedance refluxes in 83 patients. In this latter group (83 pts), the median number of cough episodes was 12.0 (5.0-25.5), of which 48.15% (30.15-71.43%) were preceded by refluxes; GER-preceded cough episodes were similar in the three groups. The majority of children had cough episodes preceded by acid refluxes in the total population (78.3%), in Group B (80.5%) and in Group C (93.7%), but not in Group A (40.0%; P < 0.001).

CONCLUSIONS

In addition to acid, also a significant proportion of WA GER may precede cough episodes in young children with persistent cough, possibly explaining the inconstant effects of anti-acid treatment on respiratory symptoms.

Clinical and pharmacological aspects of immunoprophylaxis for respiratory syncytial virus infection in high-risk infants

Respiratory syncytial virus (RSV) is the leading cause of respiratory tract infection in infants and young children throughout the world. Although preterm birth has been considered for years the major risk factor for severe disease and hospitalization, recent findings indicate that prematurity is not a necessary condition, but one of the independent risk factors for severe RSV infection, together with chronic lung diseases, congenital heart disease and immunodeficiency. Furthermore, over 50% of infants hospitalized for RSV infections during the first year of life are healthy, full-term newborns, suggesting that other environmental and individual factors may be involved. Unfortunately, there is still no specific therapy against RSV infection and therefore prophylactic measures seem to be the only intervention to avoid disease complications. No safe and effective RSV vaccine is available for the prevention of serious RSV infection. Therefore, in addition to hygienic measures, the only approach is passive immunoprophylaxis with humanized monoclonal anti-RSV antibodies, such as palivizumab that have been developed for clinical use. Because of the high cost of these antibodies, a better definition of the individual risk profile for severe RSV infection and timing of administration is needed for optimal effectiveness and careful use of limited health care resources. In this article, we have reviewed the clinical and pharmacological aspects of immunoprophylaxis with monoclonal antibodies for preventing RSV infection in high-risk infants.

Pulmonary function and airway responsiveness in young competitive swimmers

RATIONALE

Strong physical activities are often associated with large lung volumes and relatively reduced flow, which may represent a physiological variant but also an obstructive abnormality. Competitive swimmers have also spirometric values even larger than other athletes, although they are at increased risk for asthma or airway hyperresponsiveness.

AIM

We aimed to investigate whether lung volumes increase with duration of swimming training and are related to an obstructive abnormality associated with airway hyperresponsiveness and asthma-like symptoms.

METHODS

Forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC), airway responsiveness, and skin prick test were measured in 34 children/adolescents (age: 7-19 yrs old) trained for competitive swimming. Their "lifetime" exposure, i.e., the hours spent in pool was very strongly correlated with their age at the time of study. The effect of swimming activity was therefore estimated from the relationships between lung function data and age.

RESULTS

FVC Z-score was positively correlated with age, indicating that absolute values increased more than expected with normal growth, but FEV(1)/FVC was negatively correlated with age. Although the majority of subjects had allergic sensitization to aeroallergens and about one half had asthma-like symptoms and/or airway hyperresponsiveness, these conditions did not alter the relationships between lung function and age.

CONCLUSION

Intense swimming activity may cause a greater than normal lung growth, irrespective of the presence of allergic sensitization or airway hyperresponsiveness. The associated reduction of FEV(1) /FVC may represent a physiological variant rather than a true obstructive abnormality.

Pharmacological modulation of the bradykinin-induced differentiation of human lung fibroblasts: effects of budesonide and formoterol

OBJECTIVE

Bradykinin (BK) induces differentiation of lung fibroblasts into myofibroblasts, which play an important role in extracellular matrix remodeling in the airways of asthmatic patients. It is unclear whether this process is affected by antiasthma therapies. Here, we evaluated whether a glucocorticoid, budesonide (BUD), and a long-acting β2-agonist, formoterol (FM), either alone or in combination, modified BK-induced lung fibroblast differentiation, and affected the BK-activated intracellular signaling pathways.

METHODS

Human fetal lung fibroblasts were incubated with BUD (0.001-0.1 μM) and/or FM (0.0001-0.1 μM) before exposure to BK (0.1 or 1 μM). Fibroblast differentiation into α-smooth-muscle-actin-positive (α-SMA⁺) myofibroblasts, BK2 receptor (B2R) expression, extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation (p-ERK1/2), intracellular Ca²⁺ concentration ([Ca²⁺]i), and p65 nuclear factor kappa B translocation were evaluated.

RESULTS

BUD (0.1 μM) and FM (0.1 μM), either alone or in combination, completely inhibited BK-induced α-SMA protein expression and decreased the numbers of α-SMA⁺ fibroblasts, with a clear reduction in α-SMA stress fibers organization. BUD also completely inhibited the increase of B2R, whereas FM with or without BUD had no effect. BK-induced increases of [Ca²⁺]i and p-ERK1/2 were significantly reduced to similar levels by BUD and FM, either alone or in combination, whereas p65 translocation was completely inhibited by all treatments.

CONCLUSION

Both BUD and FM, either alone or in combination, effectively inhibited the BK-induced differentiation of fibroblasts into α-SMA⁺ myofibroblasts and the intracellular signaling pathways involved in fibroblast activation. These results suggest that BUD and FM combination therapy has potential to inhibit fibroblast-dependent matrix remodeling in the airways of asthmatic patients.

Breathlessness perception assessed by visual analogue scale and lung function in children with asthma: a real-life study

BACKGROUND

In children with asthma, discrepancies between objective indicators of airway obstruction and symptom perception are often observed. Although visual analogue scale (VAS) has been proposed as a useful tool for assessing accurate symptom perception, previous studies conducted in children with asthma included only small cohorts. A study was therefore designed to investigate the usefulness of VAS in establishing a reliable relationship between breathlessness perception and lung function in a large cohort of children with clinical diagnosis of asthma.

METHODS

A total of 703 children [470 boys and 233 girls, median age 10.29 (8.33-12.58) yr] with asthma were included in this cross-sectional, real-life study. Perception of breathlessness was assessed by using VAS, and lung volumes and expiratory flows were measured by spirometry.

RESULTS

Most children had intermittent or mild persistent asthma (93.3%), and only 46 children had a significant bronchial obstruction defined by FEV(1) values <80% of predicted. Globally, VAS was significantly, even though weakly, related to lung function. Analyzing children with bronchial obstruction, a moderate relationship between both FEV(1) (r = 0.47) and FEF(25-75) (r = 0.42) and VAS was detected. A VAS value of 6 was found to be a reliable cutoff for discriminating children with bronchial obstruction (AUC 0.83 at ROC curve; OR 9.4).

CONCLUSION

The present study demonstrates that VAS might be considered a useful tool to assess symptom perception, mainly in children with airflow limitation.

Exhaled nitric oxide is related to bronchial eosinophilia and airway hyperresponsiveness to bradykinin in allergen-induced asthma exacerbation

Exhaled nitric oxide (FeNO) has been associated with bronchial eosinophilia and with airway hyperresponsiveness (AHR) in mild stable asthma. We previously demonstrated in a large project that allergen exposure is able to raise FeNO and to worsen AHR to bradykinin. We postulated that allergen-induced increase in FeNO could be related to heightened mucosal eosinophils and AHR to bradykinin in atopic asthma. We performed a new immunohistochemical analysis on bronchial biopsy specimens, previously obtained from the same large project, in order to assess the number of mucosal eosinophils (EG-2+ cell) and other inflammatory cells at 48 hours after diluent and allergen exposures. Inflammatory cell counts were related to FeNO and AHR to BK (expressed as logPD20 bradykinin). In 10 atopic mild asthmatics, we found that the numbers of EG-2+ and CD4+ cells in bronchial submucosa were significantly increased after allergen compared to the respective counts after diluent (p &#x003C; 0.01). EG-2+ cells in the bronchial submucosa were negatively correlated with logPD20 bradykinin only after allergen challenge (rho = -0.709, p = 0.027). We also found a positive strong correlation between EG-2+ cells and FeNO values in atopic asthmatics at 48 hours after both diluent (rho = 0.746, p = 0.017) and allergen (rho = 0.644, p = 0.049) challenge. FeNO values negatively correlated with responsiveness to bradykinin only after allergen challenge (rho = -0.675, p = 0.039). This study indicates that after allergen exposure heightened level of exhaled NO may reflect augmented airway eosinophilic inflammation and airway responsiveness to bradykinin indicating loss of asthma control.

[Improving dietary habits in the effective prevention of excess weight and obesity]

The new research survey "Okkio alla salute", conducted in children in the 3rd year of elementary school, has confermed the worrisome phenomenon of the high number of obese and overweight children. Therefore, it is necessary, also in light of the few available resources, to fight back against this phenomenon that has been demonstrated to be a cause of disabling illnesses in adults. There must therefore be collaboration between Departments of Prevention and Hygiene and Nutrition services (SIAN) to build valid and efficient pathways. In this presentation we describe some national projects carried out by various local health agencies to address this health problem.

Acid and weakly acid gastroesophageal refluxes and type of respiratory symptoms in children

OBJECTIVES

To evaluate the association between the frequency of acid reflux (AR) and weakly acid reflux (WAR) and specific respiratory symptoms (RS) in childhood.

STUDY DESIGN

We retrospectively reviewed medical records of children with difficult-to-treat RS, not under acid suppressive therapy, and with a positive multiple intraluminal esophageal impedance (pH/MII) monitoring. To discriminate children with prevalent AR and WAR events, a ROC curve was designed and the distribution of the different RS in children with prevalent AR or WAR events was analyzed.

RESULTS

A higher number of AR over WAR events was detected (p < 0.0001) but the WAR-to-AR events ratio progressively decreased with the age of the subjects (p < 0.01). Similar total number of reflux events was found in the three age group and in children with a more prevalent WAR or AR. The most prevalent RS, equally distributed among the three age groups, were persistent and/or nocturnal cough, wheezy bronchitis/asthma, and recurrent lower respiratory tract infections (RLRTI). Apnoea was most frequent in infants (p = 0.036). A higher frequency of RLRTI, but not of nocturnal cough or wheezy bronchitis/asthma, was shown in WAR as compared with AR patients (p = 0.040), and specifically those in the school-aged group (p = 0.013). Age and WAR were respectively identified as independent predictors of apnoea and RLRTI (p < 0.05).

CONCLUSION

WAR events are common in children with gastroesophageal reflux and difficult-to-treat RS and often associated with RLRTI. These findings support the role of pH/MII monitoring in the evaluation of these patients and may explain the disappointing clinical results often observed with anti-acid treatments.

IgE in childhood asthma: relevance of demographic characteristics and polysensitisation

BACKGROUND

Despite the therapeutic efficacy of the anti-IgE monoclonal antibody, the role of IgE in allergic asthma is still a matter of debate. This may be mostly relevant in childhood, where a wide range of total serum (s) IgE levels is often detected.

AIM

To evaluate whether the relationships between total or allergen-specific sIgE levels and the clinical markers of allergic inflammation and the pulmonary function values might be affected by the demographic characteristics of the patients or by the presence of multiple sensitisations to allergens.

METHODS

64 asthmatic children sensitised to house dust mites (HDM) were evaluated. The role of age, sex and multiple sensitisations was evaluated by multiple regression model (MRM) analysis.

RESULTS

Total and HDM-specific sIgE levels (Log) showed similar moderate-to-strong correlations with exhaled nitric oxide (FENO) and blood eosinophilia (Log) (p<0.0001) but not with forced vital capacity, forced expiratory volume in 1 s (FEV(1)), %FEV(1) change after salbutamol. The positive associations between total sIgE levels and Log FENO levels or Log blood eosinophilia were also detected by MRM analysis. Age brought a negative, although limited, contribution to FENO levels and blood eosinophilia (p<0.043). Positive similar associations were also detected between HDM-specific sIgE levels and FENO levels or blood eosinophilia; however, no significant contribution of age or of other covariates was detected.

CONCLUSION

In childhood allergic asthma, total and HDM-specific sIgE levels are tightly linked to markers of allergic inflammation but not to pulmonary functions. These relationships are weakly affected by age but not by sex or by the presence of multiple sensitisations.

Determinants of exhaled nitric oxide levels (FeNO) in childhood atopic asthma: evidence for neonatal respiratory distress as a factor associated with low FeNO levels

BACKGROUND

In allergic asthmatic children exhaled nitric oxide (FeNO) levels are related to eosinophilic inflammation by correlation analysis. Whether FeNO can be modified by factors potentially influencing the natural history of asthma in early life is not known.

OBJECTIVE

To evaluate the frequency of anamnestic factors influencing the natural history of asthma and to identify potential determinants for elevated or low FeNO levels by multivariate analysis.

METHODS

One hundred seventy-one children with mild-moderate asthma were stratified according to their FeNO levels into three groups: low (<20 ppb), mid (20-40 ppb), and high (>40 ppb). The frequency of nine anamnestic factors together with indices of allergic sensitization (total and allergen-specific immunoglobulin E [IgE], blood eosinophil counts) and of airflow limitation (forced expiratory volume in one second [FEV(1)]% predicted) were evaluated. Results. Among factors related to the patient history, neonatal respiratory distress was reported only in children with low FeNO levels, whereas this factor was never reported in children with mid-to-high FeNO levels (p = .008). As compared with low FeNO group, mid and high FeNO groups showed higher eosinophil counts and a tendency to have lower FEV(1) values. By multivariate analysis, four factors (eosinophils >300 cells/mm(3), cat-specific IgE, house dust mites [HDM]-specific IgE, FEV(1) ≤ 86% predicted) turned out to be significantly associated with mid-high FeNO levels and two factors (eosinophils >600 cells/mm(3), total IgE >355 kU/L) with high FeNO levels.

CONCLUSIONS

Besides confirming the well-known tight association between blood eosinophilia and/or allergic sensitization and FeNO, these data provide new evidence for neonatal respiratory distress as potential factor associated with low FeNO levels in childhood atopic asthma.