Differential expression of cysteinyl leukotriene receptors 1 and 2 in tonsils of children with obstructive sleep apnea syndrome or recurrent infection

Efficacy of montelukast for adenoid hypertrophy in paediatrics: A systematic review and meta-analysis

INTRODUCTION

Leukotrienes play a significant role in the pathogenesis of adenoid hypertrophy (A.H.). Therefore, we aimed to analyse the role of montelukast, a leukotriene receptor antagonist, alone or in combination with mometasone, a potent local intranasal steroid, for the treatment of A.H.

METHODS

Participants were children with A.H. were treated with montelukast alone or montelukast and mometasone furoate. The main outcome measures were effect of montelukast on clinical symptoms of A.H. A literature review was conducted using online search engines, Cochrane Library, PubMed, Web of Science and Scopus, for randomized clinical trials assessing children with A.H. treated with montelukast alone or montelukast and mometasone furoate. Seven randomized clinical trials (RCTs) were included with 742 children.

RESULTS

Our study reveals that montelukast alone or in combination with intranasal mometasone furoate significantly improves clinical symptoms of adenoid hypertrophy such as snoring, sleeping disturbance, mouth breathing and A/N ratio. Montelukast was superior to placebo in decreasing snoring (SMD = -1.00, 95% CI [-1.52, -0.49]), sleep discomfort (SMD = -1.26, 95% CI [-1.60, -0.93]), A/N ratio (MD = -0.11, 95% CI [-0.14, -0.09]) and mouth breathing (SMD = -1.36, 95% CI [-1.70, -1.02]). No difference was detected between montelukast and mometasone versus mometasone alone in snoring (SMD = -0.21, 95%CI [-0.69, 0.27]); however, the combination group was superior to the mometasone alone in mouth breathing (SMD = -0.46, 95% CI [-0.73, -0.19]).

CONCLUSIONS

The limitation of studies included a small sample size, with an overall low to medium quality. Thus, further larger, higher-quality RCTs are recommended to provide more substantial evidence.

Infants hospitalized with lower respiratory tract infections during the first two years of life have increased risk of pediatric obstructive sleep apnea

RATIONALE

Lower respiratory tract infections (LRTI) during the first 2 years of life increase the risk of pediatric obstructive sleep apnea (OSA), but whether this risk varies by LRTI severity is unknown.

METHODS

We analyzed data from 2962 children, aged 0-5 years, with early-life LRTI requiring hospitalization (severe LRTI, n = 235), treated as outpatients (mild LRTI, n = 394) and without LRTI (reference group, n = 2333) enrolled in the Boston Birth Cohort. Kaplan-Meier survival estimates and Cox proportional hazards models adjusted by pertinent covariables were used to evaluate the risk of pediatric OSA.

RESULTS

Compared to children without LRTI, those with mild LRTI were at a higher risk of having OSA (hazard ratio [HR] 1.44, 95% confidence interval [CI]: 1.01-2.05), and those with severe LRTI were at the highest risk (HR 2.06, 95% CI: 1.41-3.02), independently of relevant covariables (including maternal age, race, gestational age, and type of delivery). Additional risk factors linked to a higher risk of OSA included prematurity (HR 1.34, 95% CI 1.01-1.77) and maternal obesity (HR 1.82, 95% CI 1.32-2.52). The time elapsed between LRTI and OSA diagnosis was similar in mild and severe LRTI cases, with medians of 23 and 25.5 months, respectively (p = .803).

CONCLUSION

Infants with severe early-life LRTI have a higher risk of developing OSA, and surveillance strategies to identify OSA need to be particularly focused on this group. OSA monitoring should continue throughout the preschool years as it may develop months or years after the initial LRTI hospitalization.

Co-existence of OSA and respiratory diseases and the influence of gender

INTRODUCTION

Sleep-disordered breathing (SDB), especially obstructive sleep apnea (OSA), is commonly associated with respiratory diseases, such as COPD, asthma and interstitial lung disease.

AREAS COVERED

This narrative review aims to comprehensively synthesize the existing information on SDB in respiratory diseases, investigate the role of gender in this association, and highlight the importance of OSA management in improving sleep, quality of life, and disease prognosis in these specific patient populations.

EXPERT OPINION

Research indicates a synergistic link between OSA and chronic respiratory diseases, which leads to greater morbidity and mortality compared to each disorder alone. Given the lack of an optimal OSA screening tool for these patients, a comprehensive patient approach and overnight diagnostic sleep study are imperative. Despite the limited evidence available, it seems that gender has an impact on the prevalence, severity, and susceptibility of this coexistence. Recognizing the role of gender in the coexistence of OSA and other respiratory diseases can enhance everyday medical practice and enable clinicians to adopt a more personalized approach toward optimal screening and diagnosis of these patients.

Effects of oral cysteine leukotriene receptor antagonist-montelukast on adenoid lymphoid tissue: a histopathological study under light microscope

Background: Adenoidal hypertrophy (AH) is one of the most common causes of upper airway obstruction in children. Drug and surgical treatment are the typical treatment of AH. The study on the inflammatory mechanism of AH in children provides a new idea for preoperative intervention and non-surgical treatment with anti-inflammatory drugs such as montelukast sodium (a cysteine leukotriene receptor antagonist). The aim of this study is to evaluate the effect of montelukast sodium on adenoidal lymphoid tissue pathology in children with AH under light microscope. Objective: To study whether there is any change in pathology of the adenoidal lymphoid tissue under the light microscope compared with the control group in children with moderate to severe simple AH treated with montelukast sodium for 1 month before operation. Materials and methods: Twenty patients (8 males, 12 females, 3-8 years old) with moderate to severe AH who were prepared for surgical treatment were selected. All the patients were examined by Nasopharyngeal CT and hemocyte analysis before operation. 20 subjects were randomly divided into two groups: One group was given montelukast chewable tablets 5 mg/d, qn, for 4 weeks; The control group was given placebo 5 mg/d, qn, for 4 weeks. After 4 weeks, the adenoids were removed and examined histopathology. Results: Compared with the control group, the number of lymphocytes in the blood cell analysis of the study group was significantly reduced, with a statistically significant difference (p < 0.05). And the number of germinal centers in adenoid tissue of the study group was relatively reduced, no small cyst was found in the epithelium, and the degree of inflammatory cell infiltration was reduced, with a statistically significant difference (p < 0.05). Conclusion: Montelukast can reduce the number of reactive cells, the number of lymphocytes in blood cells and blood vessels in adenoid lymphoid tissue, which can provide a new idea for preoperative intervention and non-surgical treatment of adenoid hypertrophy in children. However, this is only a pilot study and a longer treatment period is needed to assess the long-term effects of montelukast sodium on adenoid lymphoid tissue. Clinical Trial Registration: www.Chictr.org.cn, identifier ChiCTR2300075040.

150th Anniversary of global adenoid investigations: unanswered questions and unsolved problems

Although the problem of adenoid hypertrophy (AH) has been diagnosed and treated by doctors and scientists from around the world for the last 150 years, there is still no consensus regarding appropriate diagnosis, conservative treatment options, and qualification for surgery. This manuscript presents current knowledge on these issues and compares diagnostic methods and the effectiveness of treatment options. Factors that may influence the obtained treatment results are also described, and a questionnaire is proposed to compare the results of treatment. The objective of drawing attention to this problem is to obtain better results from conservative treatment in the future and better-qualified patients for surgical treatment.

Obstructive sleep apnea

Obstructive sleep apnea (OSA) is a disease that results from loss of upper airway muscle tone leading to upper airway collapse during sleep in anatomically susceptible persons, leading to recurrent periods of hypoventilation, hypoxia, and arousals from sleep. Significant clinical consequences of the disorder cover a wide spectrum and include daytime hypersomnolence, neurocognitive dysfunction, cardiovascular disease, metabolic dysfunction, respiratory failure, and pulmonary hypertension. With escalating rates of obesity a major risk factor for OSA, the public health burden from OSA and its sequalae are expected to increase, as well. In this chapter, we review the mechanisms responsible for the development of OSA and associated neurocognitive and cardiometabolic comorbidities. Emphasis is placed on the neural control of the striated muscles that control the pharyngeal passages, especially regulation of hypoglossal motoneuron activity throughout the sleep/wake cycle, the neurocognitive complications of OSA, and the therapeutic options available to treat OSA including recent pharmacotherapeutic developments.

Lower respiratory tract infections in early life are associated with obstructive sleep apnea diagnosis during childhood in a large birth cohort

STUDY OBJECTIVES

Several birth cohorts have defined the pivotal role of early lower respiratory tract infections (LRTI) in the inception of pediatric respiratory conditions. However, the association between early LRTI and the development of obstructive sleep apnea (OSA) in children has not been established.

METHODS

To investigate whether early LRTIs increase the risk of pediatric OSA, we analyzed clinical data in children followed during the first 5 years in the Boston Birth Cohort (n = 3114). Kaplan-Meier survival estimates and Cox proportional hazards models adjusted by pertinent covariates were used to evaluate the risk of OSA by the age of 5 years between children with LRTI during the first 2 years of life in comparison to those without LRTI during this period.

RESULTS

Early life LRTI increased the risk of pediatric OSA independently of other pertinent covariates and risk factors (hazard ratio, 1.53; 95% CI, 1.15 to 2.05). Importantly, the association between LRTI and pediatric OSA was limited to LRTIs occurring during the first 2 years of life. Complementarily to this finding, we observed that children who had severe respiratory syncytial virus bronchiolitis during infancy had two times higher odds of OSA at 5 years in comparison with children without this exposure (odds ratio, 2.09; 95% CI, 1.12 to 3.88).

CONCLUSIONS

Children with severe LRTIs in early life have significantly increased risk of developing OSA during the first 5 years of life. Our results offer a new paradigm for investigating novel mechanisms and interventions targeting the early pathogenesis of OSA in the pediatric population.

Study of montelukast in children with sickle cell disease (SMILES): a study protocol for a randomised controlled trial

Background

Young children with sickle cell anaemia (SCA) often have slowed processing speed associated with reduced brain white matter integrity, low oxygen saturation, and sleep-disordered breathing (SDB), related in part to enlarged adenoids and tonsils. Common treatments for SDB include adenotonsillectomy and nocturnal continuous positive airway pressure (CPAP), but adenotonsillectomy is an invasive surgical procedure, and CPAP is rarely well-tolerated. Further, there is no current consensus on the ability of these treatments to improve cognitive function. Several double-blind, randomised controlled trials (RCTs) have demonstrated the efficacy of montelukast, a safe, well-tolerated anti-inflammatory agent, as a treatment for airway obstruction and reducing adenoid size for children who do not have SCA. However, we do not yet know whether montelukast reduces adenoid size and improves cognition function in young children with SCA.

Methods

The Study of Montelukast In Children with Sickle Cell Disease (SMILES) is a 12-week multicentre, double-blind, RCT. SMILES aims to recruit 200 paediatric patients with SCA and SDB aged 3–7.99 years to assess the extent to which montelukast can improve cognitive function (i.e. processing speed) and sleep and reduce adenoidal size and white matter damage compared to placebo. Patients will be randomised to either montelukast or placebo for 12 weeks. The primary objective of the SMILES trial is to assess the effect of montelukast on processing speed in young children with SCA. At baseline and post-treatment, we will administer a cognitive evaluation; caregivers will complete questionnaires (e.g. sleep, pain) and measures of demographics. Laboratory values will be obtained from medical records collected as part of standard care. If a family agrees, patients will undergo brain MRIs for adenoid size and other structural and haemodynamic quantitative measures at baseline and post-treatment, and we will obtain overnight oximetry.

Discussion

Findings from this study will increase our understanding of whether montelukast is an effective treatment for young children with SCA. Using cognitive testing and MRI, the SMILES trial hopes to gain critical knowledge to help develop targeted interventions to improve the outcomes of young children with SCA.

Trial registration

ClinicalTrials.govNCT04351698. Registered on April 17, 2020. European Clinical Trials Database (EudraCT No. 2017-004539-36). Registered on May 19, 2020

A systematic review of the clinical evidence and biomarkers linking allergy to adeno-tonsillar disease

INTRODUCTION

allergy may be an important risk factor for adenotonsillar disease in children, although conflicting results have been reported in the literature. In previous articles, authors often failed in distinguishing between adeno-tonsillar hypertrophy and recurrent tonsillitis and in not discriminating between isolated or combined adenoid and tonsillar hypertrophy.

AIM

to evaluate clinical evidence and biomarkers linking allergy to different phenotypes of adeno-tonsillar disease. Furthermore, we questioned whether anti-allergy treatment might prevent occurrence of adeno-tonsillar disease or improve its specific management.

METHODS

our systematic review, in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) process, yielded 1010 articles finally screened. This resulted in 21 full texts that were included in a qualitative analysis.

RESULTS

literature data support the association between allergy and combined adeno-tonsillar hypertrophy and isolated adenoid hypertrophy, whereas describe a mainly negative correlation between allergy and isolated tonsillar hypertrophy. The results of this review suggest that local allergic inflammation may play a role in adeno-tonsillar hypertrophy. Data correlating bacterial recurrent tonsillitis and allergy are few, although evidence from the lab revealed that allergy might suppress innate immunity in tonsillar tissue by reducing levels of anti-microbial proteins.

CONCLUSION

basing on our qualitative analyses allergy should not be misdiagnosed in children with combined adenotonsillar hypertrophy or isolated adenoid hypertrophy, whereas evidence do not support a link between allergy and isolated tonsil hypertrophy. Finally, some data support a link between allergy and recurrent adeno-tonsillar infection although future studies are required to confirm this data. We summarized our conclusions in a practical algorithm.

Impact of Snoring on Telomere Shortening in Adolescents with Atopic Diseases

Atopic diseases can impose a significant burden on children and adolescents. Telomere length is a cellular marker of aging reflecting the impact of cumulative stress exposure on individual health. Since elevated oxidative stress and inflammation burden induced by chronic atopy and snoring may impact telomere length, this study aimed to investigate whether snoring would moderate the relationship between atopic diseases and telomere length in early adolescence. We surveyed 354 adolescents and their parents. Parents reported the adolescents' history of atopic diseases, recent snoring history as well as other family sociodemographic characteristics. Buccal swab samples were also collected from the adolescents for telomere length determination. Independent and combined effects of atopic diseases and snoring on telomere length were examined. Among the surveyed adolescents, 174 were reported by parents to have atopic diseases (20 had asthma, 145 had allergic rhinitis, 53 had eczema, and 25 had food allergy). Shorter TL was found in participants with a history of snoring and atopic diseases (β = -0.34, p = 0.002) particularly for asthma (β = -0.21, p = 0.007) and allergic rhinitis (β = -0.22, p = 0.023). Our findings suggest that snoring in atopic patients has important implications for accelerated telomere shortening. Proper management of atopic symptoms at an early age is important for the alleviation of long-term health consequences at the cellular level.

Obstructive Sleep Apnea and Asthma: More Than Chance?

Purpose of Review

To discuss the current evidence regarding the association and mechanistic interaction between asthma and obstructive sleep apnea (OSA).

Recent Findings

The co-existence of OSA is highly prevalent in asthmatics and significantly associated with increased severity, decreased control, more frequent exacerbations, and hospitalizations despite medical management. Pre-existing asthma may also be a risk factor for new onset OSA. Rhinitis, obesity, and gastro-esophageal reflux are risk factors in both conditions. The obese asthmatic with OSA may present a unique phenotype. Positive airway pressure in severe asthma improves outcomes.

Summary

Pathophysiologic mechanisms and co-morbidities overlap between OSA and asthma, but the exact link has yet to be confirmed. Screening for OSA is recommended in those with severe asthma. Further investigations are needed to delineate the cellular processes with therapeutic targets. Similarly, prospective investigations are needed to evaluate the longitudinal relationship in pre-existing asthma and the development of OSA.

Contribution of comorbidities to obesity-related asthma in children

Children with obesity are at increased risk for developing asthma that is difficult to control. A complicating factor to asthma management among these children is likely the commonplace co-morbidities that also result from obesity. We discuss three common obesity-related comorbidities which appear to complicate the effective management of asthma, including hypovitaminosis D, obstructive sleep apnea and gastro-esophageal reflux. Each conditions requires more research to understand their effects on asthma management.

Surgical versus Non-Surgical Management of Obstructive Sleep-disordered Breathing in Children: A Meta-analysis

Background:

Obstructive sleep-disordered breathing (OSDB) is a term for several chronic conditions in which partial or complete cessation of breathing occurs many times throughout the night, resulting in fatigue or daytime sleepiness that interferes with a person’s functions and reduces the quality of life.

Objective:

Comparing the effectiveness of surgical versus non-surgical treatment of OSDB in children in clinical trials through a meta-analysis study.

Patients and Methods:

A number of available studies and abstracts concerning the surgical versus non-surgical treatment of OSDB in children were identified through a comprehensive search of electronic databases. Data were abstracted from every study in the form of a risk estimate and its 95% confidence interval.

Results:

The current study revealed that there was a statistically significant improvement in the surgically treated patients rather than non-surgically treated patients regarding the quality of life.

Conclusion:

The current meta-analysis reports a significant clinical improvement in the surgical (adenotonsillectomy) group as compared to the non-surgical group, in terms of disease specific quality of life, and healthcare utilization in spite of the availability of only one study.

Short-term effect of adenotonsillectomy on growth and nutritional anthropometric parameters of children with obstructive adenotonsillar enlargement

Background

Obstructive adenotonsillar enlargement is known to cause failure to thrive in children. The effect of adenotonsillectomy is not well documented on the growth of affected children. The study was carried out to investigate the effect of adenotonsillectomy on growth of children with obstructive adenotonsillar enlargement. It was a quasi-experimental study consisting of 62 children (≤ 12 years) with obstructive adenotonsillar enlargement and 62 healthy controls. Variables measured at baseline, sixth week and 13th week post adenotonsillectomy, were weight, height, mid-upper arm circumference, and triceps skinfold thickness. The percent of weight-for-age and height-for-age were, respectively, calculated by dividing the child’s weight and height by the median expected weight and height (i.e., the 50th percentile) based on the child’s chronological age. The obtained weight-for-age and height-for-age values were used to determine the presence of failure to thrive and stunting, respectively.

Results

Majority (70.6%) of the patients with malnutrition were from a low socioeconomic class. At baseline, failure to thrive and stunting were found among 17 (26.4%) cases and 11 (17.7%) controls, but the proportion reduced to six (9.7%) and three (4.8%), respectively, at the 13th week post adenotonsillectomy. There was a steady increase in weight-for-age, height-for-age, mid-upper arm circumference, and triceps skinfold thickness in both cases and controls from baseline to the 13th week. However, there was a significant difference in percentage variation of these variables between the two groups.

Conclusions

Adenotonsillectomy improved the growth of children with obstructive adenotonsillar enlargement and hence recommended in cases with failure to thrive and stunting.

Urine concentrations changes of cysteinyl leukotrienes in non-obese children with obstructive sleep apnea undergoing adenotonsillectomy

OBJECTIVE

The main objective of the study was to compare preoperative to postoperative levels of urine-Cysteinyl leukotrienes (uCysLT) in children undergoing adenotonsillectomy (AT) for obstructive sleep apnea (OSA) in order to investigate whether exaggerated leukotriene activity is the cause or consequence of OSA.

METHODS AND MATERIALS

A prospective study was conducted on non-obese children (4-10 years old) referred for overnight PSG. Children with moderate/severe OSA treated with AT were included. A second PSG study performed 2 months postoperatively to confirm OSA resolution, and those with residual OSA were excluded. Morning urine specimens after both PSG studies were obtained and pre-operative uCysLT levels were compared to postoperative levels.

RESULTS

27 children fulfilled the criteria and underwent a post-operative PSG study with three exclusions for residual OSA (postop-AHI>2), so the study group consisted of 24 children (mean age: 5.7 ± 2.1 years). Mean preoperative and postoperative AHI was 10.96 ± 5.93 and 1.44 ± 0.56 respectively. Mean preop-uCysLT were 21.14 ± 4.65, while after AT they significantly reduced to 12.62 ± 2.67 (P < 0.01).

CONCLUSION

uCysLT levels are significantly reduced after AT in non-obese children with moderate/severe OSA, suggesting that exaggerated leukotriene activity is mainly a consequence of OSA.

Increased Incidence of Obstructive Sleep Apnea in Hospitalized Children After Enterovirus Infection: A Nationwide Population-based Cohort Study

BACKGROUND

We report the first nationwide population-based cohort study using Taiwan's National Health Insurance Research Database on the association between enterovirus (EV) infection and the incidence of sleep disorders in a pediatric population.

METHODS

Two matched groups of children under 18 years of age were included in the analyses for nonapneic sleep disorder and obstructive sleep apnea (OSA). Among them, 316 subjects were diagnosed with OSA during the surveillance period, including 182 in the EV infection group and 134 in the non-EV infection group.

RESULTS

Hospitalization because of EV infection was associated with OSA after adjusting for age, sex, urbanization atopic disease and perinatal complications (adjusted hazard ratio: 1.62, 95% confidence interval: 1.18-2.21; P = 0.003). An additional factor significantly associated with sleep apnea was allergic rhinitis (hazard ratio: 4.82, 95% confidence interval: 3.45-6.72).

CONCLUSIONS

Children with severe EV infection (ie, requiring hospitalization) carry a significantly higher risk of developing OSA, particularly in those with allergic rhinitis. As pediatric obstructive sleep apnea is a treatable sleep disorder, we emphasize regular follow-up and early detection in children with EV infection.

Paediatric obstructive sleep apnoea: can our identification of surgical candidates be evidence-based?

BACKGROUND

Paediatric obstructive sleep apnoea is a common clinical condition managed by most ENT clinicians. However, despite the plethora of publications on the subject, there is wide variability, in the literature and in practice, on key aspects such as diagnostic criteria, the impact of co-morbidities and the indications for surgical correction.

METHODS

A systematic review is presented, addressing four key questions from the available literature: (1) what is the evidence base for any definition of paediatric obstructive sleep apnoea?; (2) does it cause serious systemic illness?; (3) what co-morbidities influence the severity of paediatric obstructive sleep apnoea?; and (4) is there a medical answer?

RESULTS AND CONCLUSION

There is a considerable lack of evidence regarding most of these fundamental questions. Notably, screening measures show low specificity and can be insensitive to mild obstructive sleep apnoea. There is a surprising lack of clarity in the definition (let alone estimate of severity) of sleep-disordered breathing, relying on what may be arbitrary test thresholds. Areas of potential research might include investigation of the mechanisms through which obstructive sleep apnoea causes co-morbidities, whether neurocognitive, behavioural, metabolic or cardiovascular, and the role of non-surgical management.

Evaluation of the effects of montelukast, mometasone furoate, and combined therapyon adenoid size: a randomized, prospective, clinical trial with objective data

Background/aim: The incidence of adenoid hypertrophy is 2%-3% in children. Adenoidectomy is a commonly performed procedure in children that may cause complications such as early or late bleeding (4%-5%), recurrence of adenoid tissue (10%-20%), and postoperative respiratory problems (27%). Therefore, medical therapy alternatives to adenoidectomy are important and must be tried before surgery. In this study, we investigated the efficacy of mometasone furoate, montelukast, and a combination of these drugs in pediatric patients with adenoid hypertrophy who were scheduled for reduction with medical therapy after not being recommended for surgery.Materials and methods: The study included 120 children with adenoid hypertrophy aged between 4 and 10 years. The patients were randomized into 4 separate groups, with 30 in each group. Group 1 received 100 μg of mometasone furoate per day, group 2 received 4/5 mg (for age) montelukast per day, and group 3 received mometasone furoate + montelukast. Medical therapy continued for 3 months in the treatment groups. Group 4, which comprised patients with mild symptoms, received no treatment and was the control group. The pre- and posttreatment adenoid tissue ratios in lateral neck radiographs were recorded in the four groups. Results: When radiologic measurements of adenoid-to-air passage were calculated, an improvement of 21.76% was observed in group 1 after treatment. The rate of improvement was 22.51% in group 2. There was a 21.79% reduction in adenoid size in group 3 after 3 months? treatment and 12.46% in the control group. There were statistically significant differences between pre- and posttreatment values in every single group administered corticosteroids, montelukast, and combined therapy (P < 0.05).Conclusion: According to our results, both montelukast and mometasone furoate therapies were similarly successful in treating adenoid hypertrophy. Combined therapy has no superiority over single-therapy treatment.

Urine cysteinyl leukotriene levels in children with sleep disordered breathing before and after adenotonsillectomy

OBJECTIVES

Obstructive sleep apnea (OSA) is a common problem in children and is associated with increased cardiovascular, neurobehavioral and somatic growth consequences. Cysteinyl leukotrienes (CysLTs) play a major role with local and systemic relations to the pathophysiology of OSA. The level of CysLTs in urine, blood, exhaled breath and adenotonsillar tissue of OSA children are increased. However it remains unclear whether inflammatory marker levels are alleviated after adenotonsillectomy. Therefore, we compare the urine leukotriene E4 (uLTE4) levels in children before and after adenotonsillectomy and evaluate clinical outcomes on resolution of OSA.

METHODS

Children under 15 years who suspected OSA with planned adenotonsillectomy were recruited. Sleep questionnaires, quality of life assessment by OSA-18, physical examination, lateral neck radiographs, overnight SpO₂ monitoring and uLTE4 levels were collected. 4 ± 2 weeks post-surgery, OSA-18 was reevaluated and urine was collected again.

RESULTS

Thirty-three children with sleep disordered breathing (SDB) were included (mean age 8.1 ± 2.8 years). After adenotonsillectomy, the uLTE₄ levels decreased from 961.9 (684.8-1438.2) to 708.6 (538.2-1038.8) pg/mg Cr (P = 0.009). The post-surgery score from sleep questionnaire, OSA-18 questionnaire were significant improved (P < 0.001). Obese children demonstrated an improved quality of life post-surgery, but results were poorer than normal-weight children (P = 0.01). The uLTE4 no obvious improved in obese children.

CONCLUSIONS

Adenotonsillectomy remains an effective treatment for SDB children that not only alleviated the severity of SDB and improved quality of life; it also decreased levels of the systemic inflammatory marker, uLTE4. However, benefits were more obvious in non-obese children.

Relation between asthma and sleep disordered breathing in children: is the association causal?

Over the last few decades, asthma and sleep disordered breathing (SDB) in children have experienced similar increases in prevalence, and have both been shown to have airway inflammation, leading investigators to postulate an association between asthma and SDB. However, whether this relationship is causal or not needs to be proven. In this manuscript, we use the most widely accepted epidemiologic criteria for causality, the Bradford Hill criteria, to test step-by-step whether the relation between asthma and SBD in children is causal or not. We found studies supporting 8 of the 9 criteria (strength, consistency, specificity, biological gradient, coherence and biological plausibility, experiment, and analogy) for association between asthma and SDB. However, we did not find any study showing temporality or directionality between asthma and SDB. Therefore, establishing a causal association between asthma and SDB is not yet possible.

Prevalence of M75 Streptococcus pyogenes Strains Harboring slaA Gene in Patients Affected by Pediatric Obstructive Sleep Apnea Syndrome in Central Italy

Recently we reported an association between pediatric obstructive sleep apnea syndrome (OSAS) and Group A streptococcus (GAS) sub-acute chronic tonsil colonization. We showed that GAS may contribute to tonsil hyperplasia via a streptolysin O (SLO)-dependent cysteinyl leukotrienes (CysLTs) production, which can trigger T and B cell proliferation. In the present study, we characterized the GAS strains isolated from pediatric OSAS patients in comparison with a panel of age and sex matched GAS strains unrelated to OSAS, but isolated in the same area and during the same period ranging from 2009 to 2013. We found that slaA gene, previously reported to be associated to CysLTs production pathway, was significantly associated to GAS OSAS strains. Moreover, the most numerous group (32%) of the GAS OSAS strains belonged to M75 type, and 6 out of 7 of these strains harbored the slaA gene. Multilocus Sequence Typing (MLST) experiments demonstrated that the clone emm75/ST49/ smeZ, slaA was associated to OSAS cases. In conclusion, we found an association between slaA gene and the GAS OSAS strains, and we showed that the clone emm75/ST49 harboring genes smeZ and slaA was exclusively isolated from patients affected by OSAS, thus suggesting that this genotype might be associated to the pathogenesis of OSAS, although further studies are needed to elucidate the possible role of SlaA in tonsil hypertrophy development.

Sleep-disordered breathing children: Measurement of nasal nitric oxide and fractional exhaled nitric oxide

OBJECTIVE

To assess the clinical significance of nasal nitric oxide (nNO) and fractional exhaled nitric oxide (FeNO) concentrations in children with sleep-disordered breathing (SDB).

METHODS

Enrolled in this study were 30 children with SDB and 15 healthy children. The nNO and FeNO concentrations were measured noninvasively using a NIOX MINO system (Aerocrine AB, Solna, Sweden). SPSS statistics 20.0 software (IBM SPSS statistics 20.0, Armonk, NY, USA) was used to analyze the data.

RESULTS

The median (25th and 75th percentiles) nNO concentration of SDB children measured in parts per billion (ppb) was 111.0 (44.0; 349.0) ppb; FeNO concentration of SDB children was 12.0 (9.8; 14.0) ppb. The nNO concentration of healthy children was 52.0 (22.0; 139.0) ppb; FeNO concentration of healthy children was 12.0 (10.0; 16.0) ppb. Compared to healthy children, nNO concentration was significantly higher in children with SDB (Z = -2.215, P = 0.027). Correlation analysis showed that SDB children's nNO concentration directly correlated with apnea-hypopnea index (AHI; r = 0.429, P = 0.018), and inversely correlated with nadir oxygen saturation (SaO2; r = -0.482, P = 0.007). No other polysomnographic parameters significantly correlated with nNO concentration.

CONCLUSION

Our data suggest that nNO concentration might be useful for diagnosis and evaluation of disease severity in SDB children. Furthermore, these results suggest that nNO concentration has a greater prognostic value than FeNO concentration.

Paediatric obstructive sleep apnoea syndrome (OSAS) is associated with tonsil colonisation by Streptococcus pyogenes

The involvement of pathogenic bacteria in obstructive sleep apnoea syndrome (OSAS) has yet to be elucidated. We investigated the possible role of group A streptococcus (GAS) in OSAS pathogenesis. In 40 tonsillectomized patients affected by OSAS and 80 healthy controls, significant (p < 0.0001) association of GAS with paediatric OSAS was found. Supernatant from streptolysin O (SLO)-producing GAS induced production of cysteinyl leukotrienes (CysLTs) in tonsil mononuclear cells (TMCs). CysLTs-treated TMCs showed significant (p < 0.05) proliferation of CD4+ T, CD19+ and CD19+CD27+CD38+ B lymphocytes. We discovered a SLO-dependent activation of CysLTs production through a pathway involving TOLL-like receptor 4 (TLR4), TIR-domain-containing adapter-inducing interferon-β (TRIF), Myeloid differentiation primary response gene 88 (MyD88), and p38 MAP Kinase. In conclusion, we hypothesise that GAS may contribute to paediatric tonsillar hyperplasia through CysLTs production induced by SLO, and this might explain its association with OSAS.

Measurement of nasal and fractional exhaled nitric oxide in children with upper airway inflammatory disease: Preliminary results

OBJECTIVES

To assess the clinical significance of nasal nitric oxide (nNO) and fractional exhaled nitric oxide (FeNO) concentrations in children with upper airway inflammatory disease.

METHODS

Fifteen healthy children, 30 with allergic rhinitis (AR), 10 with non-allergic rhinitis (NAR), and 30 with sleep disordered breathing (SDB) were enrolled. The FeNO and nNO concentrations were measured non-invasively using a NIOX MINO system.

RESULTS

Both nNO and FeNO were significantly higher in children with AR than in healthy children (P=0.000 and P=0.000, respectively). Compared to healthy children, nNO was also significant higher in children with NAR (P=0.011) or SDB (P=0.027). In contrast, FeNO did not differ from controls in children with NAR or SDB.

CONCLUSIONS

Our data suggest that nNO has potential value for diagnosing upper airway inflammation. Moreover, elevated FeNO distinguishes allergic from non-allergic rhinitis.

Tonsillectomy or adenotonsillectomy versus non-surgical management for obstructive sleep-disordered breathing in children

BACKGROUND

Obstructive sleep-disordered breathing (oSDB) is a condition that encompasses breathing problems when asleep, due to an obstruction of the upper airways, ranging in severity from simple snoring to obstructive sleep apnoea syndrome (OSAS). It affects both children and adults. In children, hypertrophy of the tonsils and adenoid tissue is thought to be the commonest cause of oSDB. As such, tonsillectomy - with or without adenoidectomy - is considered an appropriate first-line treatment for most cases of paediatric oSDB.

OBJECTIVES

To assess the benefits and harms of tonsillectomy with or without adenoidectomy compared with non-surgical management of children with oSDB.

SEARCH METHODS

We searched the Cochrane Register of Studies Online, PubMed, EMBASE, CINAHL, Web of Science, Clinicaltrials.gov, ICTRP and additional sources for published and unpublished trials. The date of the search was 5 March 2015.

SELECTION CRITERIA

Randomised controlled trials comparing the effectiveness and safety of (adeno)tonsillectomy with non-surgical management in children with oSDB aged 2 to 16 years.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Three trials (562 children) met our inclusion criteria. Two were at moderate to high risk of bias and one at low risk of bias. We did not pool the results because of substantial clinical heterogeneity. They evaluated three different groups of children: those diagnosed with mild to moderate OSAS by polysomnography (PSG) (453 children aged five to nine years; low risk of bias; CHAT trial), those with a clinical diagnosis of oSDB but with negative PSG recordings (29 children aged two to 14 years; moderate to high risk of bias; Goldstein) and children with Down syndrome or mucopolysaccharidosis (MPS) diagnosed with mild to moderate OSAS by PSG (80 children aged six to 12 years; moderate to high risk of bias; Sudarsan). Moreover, the trials included two different comparisons: adenotonsillectomy versus no surgery (CHAT trial and Goldstein) or versus continuous positive airway pressure (CPAP) (Sudarsan). Disease-specific quality of life and/or symptom score (using a validated instrument): first primary outcomeIn the largest trial with lowest risk of bias (CHAT trial), at seven months, mean scores for those instruments measuring disease-specific quality of life and/or symptoms were lower (that is, better quality of life or fewer symptoms) in children receiving adenotonsillectomy than in those managed by watchful waiting:- OSA-18 questionnaire (scale 18 to 126): 31.8 versus 49.5 (mean difference (MD) -17.7, 95% confidence interval (CI) -21.2 to -14.2);- PSQ-SRBD questionnaire (scale 0 to 1): 0.2 versus 0.5 (MD -0.3, 95% CI -0.31 to -0.26);- Modified Epworth Sleepiness Scale (scale 0 to 24): 5.1 versus 7.1 (MD -2.0, 95% CI -2.9 to -1.1).No data on this primary outcome were reported in the Goldstein trial.In the Sudarsan trial, the mean OSA-18 score at 12 months did not significantly differ between the adenotonsillectomy and CPAP groups. The mean modified Epworth Sleepiness Scale scores did not differ at six months, but were lower in the surgery group at 12 months: 5.5 versus 7.9 (MD -2.4, 95% CI -3.1 to -1.7). Adverse events: second primary outcomeIn the CHAT trial, 15 children experienced a serious adverse event: 6/194 (3%) in the adenotonsillectomy group and 9/203 (4%) in the control group (RD -1%, 95% CI -5% to 2%).No major complications were reported in the Goldstein trial.In the Sudarsan trial, 2/37 (5%) developed a secondary haemorrhage after adenotonsillectomy, while 1/36 (3%) developed a rash on the nasal dorsum secondary to the CPAP mask (RD -3%, 95% CI -6% to 12%). Secondary outcomesIn the CHAT trial, at seven months, mean scores for generic caregiver-rated quality of life were higher in children receiving adenotonsillectomy than in those managed by watchful waiting. No data on this outcome were reported by Sudarsan and Goldstein.In the CHAT trial, at seven months, more children in the surgery group had normalisation of respiratory events during sleep as measured by PSG than those allocated to watchful waiting: 153/194 (79%) versus 93/203 (46%) (RD 33%, 95% CI 24% to 42%). In the Goldstein trial, at six months, PSG recordings were similar between groups and in the Sudarsan trial resolution of OSAS (Apnoea/Hypopnoea Index score below 1) did not significantly differ between the adenotonsillectomy and CPAP groups.In the CHAT trial, at seven months, neurocognitive performance and attention and executive function had not improved with surgery: scores were similar in both groups. In the CHAT trial, at seven months, mean scores for caregiver-reported ratings of behaviour were lower (that is, better behaviour) in children receiving adenotonsillectomy than in those managed by watchful waiting, however, teacher-reported ratings of behaviour did not significantly differ.No data on these outcomes were reported by Goldstein and Sudarsan.

AUTHORS' CONCLUSIONS

In otherwise healthy children, without a syndrome, of older age (five to nine years), and diagnosed with mild to moderate OSAS by PSG, there is moderate quality evidence that adenotonsillectomy provides benefit in terms of quality of life, symptoms and behaviour as rated by caregivers and high quality evidence that this procedure is beneficial in terms of PSG parameters. At the same time, high quality evidence indicates no benefit in terms of objective measures of attention and neurocognitive performance compared with watchful waiting. Furthermore, PSG recordings of almost half of the children managed non-surgically had normalised by seven months, indicating that physicians and parents should carefully weigh the benefits and risks of adenotonsillectomy against watchful waiting in these children. This is a condition that may recover spontaneously over time.For non-syndromic children classified as having oSDB on purely clinical grounds but with negative PSG recordings, the evidence on the effects of adenotonsillectomy is of very low quality and is inconclusive.Low-quality evidence suggests that adenotonsillectomy and CPAP may be equally effective in children with Down syndrome or MPS diagnosed with mild to moderate OSAS by PSG.We are unable to present data on the benefits of adenotonsillectomy in children with oSDB aged under five, despite this being a population in whom this procedure is often performed for this purpose.

Sleep medicine

PURPOSE OF REVIEW

To reflect the recent advances in the field of pediatric sleep medicine. The pediatrician will be able to define which children to refer for a sleep study and what to expect from the sleep specialist in 2015.

RECENT FINDINGS

In the first study that compared adeno tonsillectomy (TA) to watchful waiting, TA reduced symptoms and improved children's behavior, quality of life, and polysomnographic results. Anti-inflammatory therapy for mild obstructive sleep apnea was effective and well tolerated according to a double-blind study. A retrospective study showed that it is beneficial for 80% of the patients. TA is associated with a decrease in asthma symptoms and medication utilization.

SUMMARY

Pediatricians need to be aware of the clear benefits of tonsillectomy (including better asthma control), although anti-inflammatory therapy may improve symptoms and polysomnographic findings in children with nonsevere obstructive sleep apnea.

Nasal nitric oxide in sleep-disordered breathing in children

BACKGROUND

Inflammation plays a role in the pathogenesis and consequences of sleep-disordered breathing (SDB). The nasal mucosa and paranasal sinuses produce high levels of nitric oxide (NO). In asthma, exhaled NO is a marker of airway inflammation. There is only limited information whether nasal NO (nNO) accompanies also chronic upper airway obstruction, specifically, SDB. The objective of this study was to investigate nNO levels in children with SDB in comparison to healthy non-snoring children.

METHODS

Nasal NO was measured in children who underwent overnight polysomnographic studies due to habitual snoring and suspected SDB and in healthy non-snoring controls.

RESULTS

One hundred and eleven children participated in the study: 28 with obstructive sleep apnea (OSA), 60 with primary snoring (PS), and 23 controls. Nasal NO levels were significantly higher in children with OSA and PS compared to controls (867.4 ± 371.5, 902.0 ± 330.9, 644.1 ± 166.5 ppb, respectively, p = 0.047). No difference was observed between children with OSA and PS. No correlations were found between nNO levels and any of the PSG variables, nor with age, BMI percentile or tonsils size.

CONCLUSIONS

Compared to healthy controls, nNO is increased in children with SDB, but it is not correlated with disease severity. This is probably due to the local mechanical processes and snoring.

Detection of common respiratory viruses in tonsillar tissue of children with obstructive sleep apnea

BACKGROUND

Early life viral infection is associated with neurogenic inflammation that is present in lymphoid tissues of the upper airway in children with obstructive sleep apnea (OSA). We hypothesized that viral genomic material is present in tonsils of children with OSA. Therefore, we examined tonsils for the presence of respiratory viruses' nucleic acids in children with OSA, and in children without OSA (undergoing surgery for recurrent throat infections (RI)).

METHODS

Tonsillar tissue from patients with OSA and RI was subjected to multiplex quantitative real time reverse transcription PCR (mqRTPCR), analyzed for the presence of common respiratory viruses' genetic material.

RESULTS

Fifty-six patients were included, of whom 34 had OSA (age (years ± S.D), 4.22 ± 1.14) and 22 with RI (4.35 ± 1.36). Respiratory viruses nucleic acids (24 detections) were observed in 17 (50%) OSA samples. In contrast, no virus was detected in RI samples (relative frequency P<0.0001). Viruses detected, based on frequency were Rhinovirus, Adenovirus, human metapneumovirus (hMPV), respiratory syncytial virus (RSV), and corona virus.

CONCLUSIONS

Respiratory viruses are detected in OSA hypertrophic tonsils, suggestive of their role in the evolution of tonsillar inflammation and hypertrophy. Early life viral infections may contribute to the pathogenesis of pediatric OSA.

Substance P and neurokinin 1 receptors as potential therapeutic targets in children with OSA

BACKGROUND

Increased substance P (SP) levels and abundant expression of neurokinin (NK) 1 receptor in adenotonsillar tissues of children with OSA but not recurrent tonsillar infection (RI) suggest that NK1 antagonists could be useful in treating OSA.

METHODS

The effects of SP and the NK1 antagonist GR-82334 were examined on mixed cell cultures prepared from dissociated tonsils harvested intraoperatively from children with OSA and RI. Proliferation was assessed by [3H]-thymidine or 5-ethynyl-2'-deoxyuridine incorporation, and inflammatory cytokine production (tumor necrosis factor [TNF]-α, IL-6, IL-1β) was assessed in supernatants by enzyme-linked immunosorbent assay.

RESULTS

SP elicited dose-dependent increases in tonsillar cell proliferation in mixed cell cultures from children with OSA but not with RI (P &lt; .0001). The NK1 antagonist exhibited dose-dependent reductions in cellular proliferative rates in OSA-derived cell cultures but not in RI-derived mixed cell cultures (P &lt; .00001). SP treatment was associated with increased TNF-α and IL-6 production, and GR-82334 abrogated SP effects, as well as reduced basal cytokine release (P &lt; .0001).

CONCLUSIONS

SP pathways appear to underlie intrinsic proliferative and inflammatory signaling pathways in tonsillar tissues from children with OSA but not with RI. Selective disruption of these pathways may provide nonsurgical alternatives for prevention and treatment of pediatric OSA.

The promise of translational and personalised approaches for paediatric obstructive sleep apnoea: an 'Omics' perspective

Obstructive sleep apnoea (OSA) can result in significant morbidities including the cardiovascular, metabolic and neurocognitive systems. These effects are purportedly mediated via activation of inflammatory cascades and the induction of oxidative stress, ultimately resulting in cellular injury and dysfunction. While great advances have been made in sleep medicine research in the past decades, there are still wide gaps in our knowledge concerning the exact underlying pathophysiological mechanisms of OSA and consequences. Without resolving these issues, the reasons why patients with a similar severity of OSA can have markedly different clinical presentation and end-organ morbidity, that is, phenotype, will continue to remain elusive. This review aims to highlight the recent exciting discoveries in genotype-phenotype interactions, epigenetics, genomics and proteomics related to OSA. Just as PCR revolutionised the field of genetics, the potential power of 'Omics' promises to transform the field of sleep medicine, and provide critical insights into the downstream pathological cascades inherent to OSA, thereby enabling personalised diagnosis and management for this highly prevalent sleep disorder.

A pro-inflammatory role for nuclear factor kappa B in childhood obstructive sleep apnea syndrome

STUDY OBJECTIVES

Childhood obstructive sleep apnea syndrome (OSAS) is associated with an elevation of inflammatory markers such as C-reactive protein (CRP) that correlates with specific morbidities and subsides following intervention. In adults, OSAS is associated with activation of the transcription factor nuclear factor kappa B (NF-kB). We explored the mechanisms underlying NF-kB activation, based on the hypothesis that specific NF-kB signaling is activated in children with OSAS.

DESIGN

Adenoid and tonsillar tissues from children with OSAS and matched controls were immunostained against NF-kB classical (p65 and p50) and alternative (RelB and p52) pathway subunits, and NF-kB-dependent cytokines: interleukin (IL)- 1α, IL-1β, tumor necrosis factor-α, and IL-8). Serum CRP levels were measured in all subjects. NF-kB induction was evaluated by a luciferase-NF-kB reporter assay in L428 cells constitutively expressing NF-kB and in Jurkat cells with inducible NF-kB expression. p65 translocation to the nucleus, reflecting NF-kB activation, was measured in cells expressing fluorescent NF-kB-p65-GFP (green fluorescent protein).

SETTING

Sleep research laboratory.

PATIENTS OR PARTICIPANTS

Twenty-five children with OSAS and 24 without OSAS.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Higher expression of IL-1α and classical NF-kB subunits p65 and p50 was observed in adenoids and tonsils of children with OSAS. Patient serum induced NF-kB activity, as measured by a luciferase-NF-kB reporter assay and by induction of p65 nuclear translocation in cells permanently transfected with GFP-p65 plasmid. IL-1β showed increased epithelial expression in OSAS tissues.

CONCLUSIONS

Nuclear factor kappa B is locally and systemically activated in children with obstructive sleep apnea syndrome. This observation may motivate the search for new anti-inflammatory strategies for controlling nuclear factor kappa B activation in obstructive sleep apnea syndrome.

Obstructive sleep apnea in children: a critical update

Obstructive sleep apnea (OSA) in children is a highly prevalent disorder caused by a conglomeration of complex pathophysiological processes, leading to recurrent upper airway dysfunction during sleep. The clinical relevance of OSA resides in its association with significant morbidities that affect the cardiovascular, neurocognitive, and metabolic systems. The American Academy of Pediatrics recently reiterated its recommendations that children with symptoms and signs suggestive of OSA should be investigated with polysomnography (PSG), and treated accordingly. However, treatment decisions should not only be guided by PSG results, but should also integrate the magnitude of symptoms and the presence or absence of risk factors and signs of OSA morbidity. The first-line therapy in children with adenotonsillar hypertrophy is adenotonsillectomy, although there is increasing evidence that medical therapy, in the form of intranasal steroids or montelukast, may be considered in mild OSA. In this review, we delineate the major concepts regarding the pathophysiology of OSA, its morbidity, diagnosis, and treatment.

Newer treatment modalities for pediatric obstructive sleep apnea

The obstructive sleep apnea syndrome is common and its prevalence is expected to increase with the current obesity epidemic. If left untreated, it is associated with important morbidity such as growth failure, neurocognitive impairment, systemic and pulmonary hypertension, and endothelial dysfunction. Recent research has shown that many children, especially the obese or those with other underlying medical conditions, have residual obstructive sleep apnea after adenotonsillectomy (the primary treatment for childhood obstructive sleep apnea). These children could be effectively treated with continuous positive airway pressure but poor adherence is a significant limitation of this therapy. Therefore, new treatment modalities for the pediatric obstructive sleep apnea syndrome are needed. Current research has focused on newer therapies for pediatric obstructive sleep apnea, such as anti-inflammatories, dental treatments, high-flow nasal cannula, and weight loss. However, there are few randomized controlled trials assessing the effectiveness of these therapies. Further research is warranted.

Obstructive sleep apnea and asthma: associations and treatment implications

Obstructive sleep apnea (OSA) and asthma are highly prevalent respiratory disorders and are frequently co-morbid. Risk factors common to the two diseases include obesity, rhinitis, and gastroesophageal reflux (GER). Observational and experimental evidence implicates airways and systemic inflammation, neuromechanical effects of recurrent upper airway collapse, and asthma-controlling medications (corticosteroids) as additional explanatory factors. Therefore, undiagnosed or inadequately treated OSA may adversely affect control of asthma and vice versa. It is important for clinicians to be vigilant and specifically address weight-control, nasal obstruction, and GER in these populations. Utilizing validated screening instruments to affirm high risk of co-morbid OSA or asthma in persistently symptomatic patients will allow clinicians to cost-effectively test and treat appropriate patients, potentially improving outcomes. While non-invasive ventilation in acute asthma improves outcomes, the role of chronic continuous positive airway pressure (CPAP; the first-line treatment for OSA) in improving long-term asthma control is not known. Future research should focus on the impact of optimal CPAP therapy and adherence on asthma symptoms and outcomes.

Long-term continuous positive airway pressure therapy normalizes high exhaled nitric oxide levels in obstructive sleep apnea

STUDY OBJECTIVES

Upper airway inflammation and oxidative stress have been implicated in the pathogenesis of obstructive sleep apnea (OSA) and may be linked to cardiovascular consequences. We prospectively examined fraction of exhaled nitric oxide (FENO), a surrogate marker of upper airway inflammation using a portable nitric oxide analyzer (NIOX MINO).

DESIGN

In consecutive adult nonsmokers with suspected OSA, FENO was measured immediately before and after polysomnographic studies, and within 1-3 months following continuous positive airway pressure (CPAP) therapy.

MEASUREMENT AND RESULTS

FENO levels were increased in the 75 patients with OSA compared to the 29 controls, both before sleep (13.4 ± 6.5 ppb vs. 6.5 ± 3.5; p < 0.001) and after sleep (19.0 ± 7.7 ppb vs. 6.9 ± 3.7; p < 0.001). Furthermore, in patients with OSA, FENO levels were significantly higher post-sleep than pre-sleep (19.0 ± 7.7 ppb vs. 13.4 ± 6.5; p < 0.001), while there was no significant overnight change in patients without OSA. The rise in FENO correlated with the apnea-hypopnea index (r = 0.65, p < 0.001), nadir oxygen saturation (r = 0.54, p < 0.001), and arousal index (r = 0.52, p < 0.001). Thirty-seven of these patients underwent CPAP titration and treatment. Successful titration was associated with a lower overnight increase in FENO (7.2 ± 3.3 vs. 11.0 ± 4.3, p = 0.02). FENO levels declined after 1-3 months of CPAP therapy (11.7 ± 4.4 ppb, p < 0.001).

CONCLUSIONS

FENO levels are elevated in OSA, correlate with severity, and decrease after positive pressure therapy. This study supports the role of upper airway inflammation in OSA pathogenesis and a possible role for FENO in monitoring CPAP therapy.

Genotype-phenotype interactions in pediatric obstructive sleep apnea

Pediatric sleep disordered breathing (PSDB) is not only a very frequent condition affecting 2-4% of all children, but is also associated with an increased risk for a variety of manifestations underlying end-organ injury and dysfunction that impose both immediate and potentially long-term morbidities and corresponding inherent elevations in healthcare costs. One of the major problems with the creation of valid algorithms aiming to stratify diagnostic and treatment prioritization lies in our current inability to predict and identify those children who are most at-risk for PSDB-induced adverse consequences. Thus, improved our understanding of the mechanisms governing phenotype variance in PSDB is essential. Here, we examine some of the potential underpinnings of phenotypic variability in PSDB, and further propose a conceptual framework aimed at facilitating the process of advancing knowledge in this frequent disorder.

Novel pharmacological approaches for treatment of obstructive sleep apnea in children

INTRODUCTION

The lymphadenoid tissues in the upper airway are sparse and organized lympho-epithelial structures playing an important role against foreign pathogens, with the palatine tonsils being the major components of the lymphoid tissues contained in the Waldeyer's ring. Obstructive sleep apnea (OSA) has emerged as a very frequent condition in the pediatric age range that is associated with substantial neurobehavioral, cardiovascular and metabolic morbidities. Adenotonsillar hypertrophy is the major pathophysiological contributor to OSA occurrence in children.

AREAS COVERED

Here, the authors provide a systematic review and summary of some of the known histological and pathological features of human lymphadenoid tissues and their fundamental immunological functions, provide insights into the pathophysiology of pediatric OSA, particularly focusing on inflammatory pathways and the available outcomes associated with targeting such pathways with compounds such as corticosteroids and leukotriene modifiers. Furthermore, they present findings from an unbiased approach to discovery of therapeutic targets and formulate constructs toward putative future interventional approaches for this highly prevalent condition.

EXPERT OPINION

Surgical approaches for pediatric OSA may not be as effective as previously anticipated. Accordingly, expanded use of existing systemic or topical anti-inflammatory agents or development of novel compounds targeting selected immune cell populations underlying pathophysiological determinants of OSA is needed.

Montelukast for children with obstructive sleep apnea: a double-blind, placebo-controlled study

OBJECTIVES

Children with nonsevere obstructive sleep apnea (OSA) benefit from alternative therapeutic interventions such as leukotriene modifiers. We hypothesized that montelukast might improve OSA in children. We tested this hypothesis in a double-blind, randomized, placebo-controlled fashion.

METHODS

Of 50 possible candidates, we recruited 46 children with polysomnographically diagnosed OSA. In this prospective, double-blind, randomized trial, children received daily oral montelukast at 4 or 5 mg (<6 or >6 years of age, respectively) or placebo for 12 weeks. Polysomnographic assessments, parent questionnaires, and radiographs to assess adenoid size were performed before and after therapy.

RESULTS

Compared with the 23 children that received placebo, the 23 children that received montelukast showed significant improvements in polysomnographic measures of respiratory disturbance (obstructive apnea index), children's symptoms, and adenoid size. The obstructive apnea index decreased by >50% in 65.2% of treated children. No attrition or side effects occurred.

CONCLUSIONS

A 12-week treatment with daily, oral montelukast effectively reduced the severity of OSA and the magnitude of the underlying adenoidal hypertrophy in children with nonsevere OSA.

Cysteinyl leukotriene receptors in tonsillar B- and T-lymphocytes from children with obstructive sleep apnea

OBJECTIVES

Cysteinyl leukotrienes have been implicated in the pathogenesis of adenotonsillar hypertrophy in children with obstructive sleep apnea (OSA). This study aimed to quantify the expression of cysteinyl leukotriene receptors (CysLT(1), CysLT(2)) by tonsillar lymphocyte subpopulations from children with OSA and to make comparisons to lymphocyte subpopulations from control subjects with recurrent tonsillitis (RT).

METHODS

Tonsillar tissue from children with OSA or RT was studied for CysLT(1) and CysLT(2) expression by RT-PCR, flow cytometry (FC), and immunofluorescence.

RESULTS

Ten children with OSA and 10 control subjects were recruited. In OSA participants, CysLT(1)+ fraction of small-size CD19+ B-lymphocytes was similar to the CysLT(1)+ CD3+ T-lymphocytes fraction (FC: 36.5 [16.5-55.4] vs. 14 [2.8-22.1]) (p>0.05) and higher than the CysLT(1)+ moderate/large-size CD19+ B-lymphocytes fraction (6.6 [1.5-14.4]) (p<0.01). Similar trends were recognized for CysLT(2). CysLT(1) and CysLT(2) immunoreactivity was detected by immunofluorescence in the tonsillar mantle zones (small B-lymphocytes) and the extrafollicular areas (T-lymphocytes). Compared to subjects with RT, children with OSA had significantly higher expression of CysLT(1) in small-size CD19+ B-lymphocytes (FC) and in CD3+ T-lymphocytes (RT-PCR and FC) (p<0.05).

CONCLUSIONS

Increased expression of leukotriene receptors by immunologically active tonsillar areas in children with OSA is a potential therapeutic target for pediatric sleep apnea.

Sleep-disordered breathing is a risk factor for community-acquired alveolar pneumonia in early childhood

BACKGROUND

Data are scarce with regard to risk factors for acute community-acquired alveolar pneumonia (CAAP) in children, but it is known that children with sleep-disordered breathing (SDB) experience more respiratory infections. We aimed to assess whether SDB is a risk factor for CAAP in early childhood.

METHODS

We conducted a prospective, nested, case-control study assessing children < 5 years old who had been given a diagnosis of CAAP based on World Health Organization radiographic criteria. Demographic and clinical data were collected. SDB symptoms were documented using a structured questionnaire. CAAP study and retrospective sleep laboratory databases were compared. SDB presence and severity were determined by questionnaire and polysomnography (PSG).

RESULTS

A total of 14,913 children underwent chest radiography during the study period; 1,546 children with radiographically proven CAAP (58% boys) and 441 control subjects (54% boys) were prospectively enrolled. Frequent snoring was reported in 18.6% vs 2.9% subjects with CAAP and control subjects, respectively (P < .001). The respective figures for subjects with CAAP and control subjects for restless sleep, nocturnal breathing problems, abnormal behavior, and chronic rhinorrhea were 21.6% vs 5.3%, 5% vs 1.4%, 6.4% vs 0.2%, and 12.9% vs 1.8%, (P < .001 for each). Fifty children (3.3%) with CAAP vs three control subjects (0.7%) underwent adenoidectomy (P < .001). PSG diagnosis of obstructive sleep apnea had been established previously in 79 patients (5%) with CAAP vs six (1.3%) of the control subjects (OR, 3.7 [95% CI, 1.6-10.0]; P < .001), with higher severity in patients with CAAP than in control subjects.

CONCLUSIONS

SDB is common in children with CAAP and is possibly a predisposing risk factor for CAAP in children < 5 years old. We recommend considering SDB in young children who are given a diagnosis of CAAP.