Anti-inflammatory therapy for obstructive sleep apnea in children

QUESTION

A 4-year-old child was diagnosed by polysomnography as experiencing mild obstructive sleep apnea (OSA). Despite the child being inattentive and distracted during the day at school, his parents prefer to avoid surgical treatment (adenotonsillectomy). Are there any non-surgical treatments for mild OSA in young children?

ANSWER

Obstructive sleep apnea in children is caused mainly by adenotonsillar hypertrophy and can lead to considerable morbidities, including neurocognitive and behavioural disturbances. Surgical removal of the tonsils and adenoids is the treatment of choice. In recent years, however, a new understanding of the inflammatory components of OSA has led to the assumption that anti-inflammatory treatment can reduce adenotonsillar size and improve OSA symptoms. Evidence from a few studies suggests that intranasal steroids and oral leukotriene receptor antagonists have beneficial effects, but data from randomized controlled trials are still lacking.

[Immune function changes in patients with obstructive sleep apnea hypopnea syndrome]

OBJECTIVE

To explore the potential changes in the immune function of patients with obstructive sleep apnea hypopnea syndrome (OSAHS).

METHODS

We carried out a retrospective cross-sectional study of 187 patients with established OSAHS and 20 healthy subjects (control). For all the patients, the medical history was carefully examined, and overnight sleep monitoring was carried out with detection of the humoral and cellular immunity.

RESULTS

We found a significant increase in the levels of C3 and a decrease in both the IgM level and NK cell percentage in OSAHS patients as compared to the control group (P<0.01). Correlation analysis indicated that C3 was positive correlated to AHI but inversely to the lowest pulse oxygen saturation (LSpO(2)); IgM showed a mild positively correlation to LSpO(2), and NK cells had a mild inverse correlation to AHI. The other immunological indices were not found to undergo noticeable changes or show correlations in OSAHS.

CONCLUSION

Immune function changes occur in patients with OSAHS, characterized primarily by deteriorations in the humoral and cellular immunity.

Sleep measures and morning plasma TNF-alpha levels in children with sleep-disordered breathing

BACKGROUND

Sleep disordered breathing in children is associated with severity-dependent increases in excessive daytime sleepiness (EDS). TNF-alpha is an inflammatory cytokine that has been implicated in EDS. Since, at any given level of apnea-hypopnea index, there is significant variability in EDS, we hypothesized that morning tumor necrosis factor (TNF)-alpha plasma levels may provide a biologic correlate of EDS.

METHODS

Children being evaluated for sleep disordered breathing underwent a blood draw after nocturnal polysomnography, and TNF-alpha plasma concentrations were assayed using ELISA. In a subset of 15 children with sleep disordered breathing and in 15 matched control subjects, whole blood cultures in the presence of lipopolysaccharide and Multiple Sleep Latency Test were conducted. Furthermore, 22 children with obstructive sleep apnea had TNF-alpha levels assayed and underwent nocturnal polysomnography and Multiple Sleep Latency Test before and after adenotonsillectomy.

RESULTS

In 298 children, morning TNF-alpha levels were globally increased in the presence of obstructive sleep apnea, particularly in more severe cases, and correlated with obstructive apnea-hypopnea index and sleep pressure score, a measure of respiratory-induced sleep fragmentation, but not with nadir Sa02. A stepwise logistic regression analysis revealed that sleep pressure score and body mass index accounted for 36.2% of the adjusted variance in TNF-alpha levels (P < 0.0001). Furthermore, multiple sleep latencies were correlated with whole blood culture-derived TNF-alpha levels (n = 15), and morning TNF-alpha levels decreased after adenotonsillectomy in 22 children.

CONCLUSIONS

TNF-alpha levels are increased in pediatric obstructive sleep apnea, are primarily driven by sleep fragmentation and body mass index, and are closely associated with the degree of sleepiness, as measured by Multiple Sleep Latency Test. Furthermore, surgical treatment of obstructive sleep apnea results in significant reductions in TNF-alpha levels with reciprocal prolongations in sleep latency.

Increased cellular proliferation and inflammatory cytokines in tonsils derived from children with obstructive sleep apnea

Adenotonsillar hypertrophy is the major pathophysiological mechanism underlying obstructive sleep apnea (OSA) and recurrent tonsillitis (RI) in children. The increased expression of various mediators of the inflammatory response in tonsils of patients with OSA prompted our hypothesis that the enhanced local and systemic inflammation in children with OSA would promote tonsillar proliferation. Mixed cell cultures from tonsils recovered during adenotonsillectomy in children with OSA and RI were established, and proliferative rates were assessed. Cells were also cultured to determine the levels of proinflammatory cytokines and antioxidant protein levels and mRNA expression. Global cell proliferative rates from OSA tonsils were significantly higher than RI (p < 0.01), with CD3, CD4, and CD8 cell proliferation being higher in OSA (p < 0.05). Moreover, proinflammatory cytokines, such as TNF-alpha, IL-6, and IL-1alpha, were highly expressed in OSA-derived tonsils. Furthermore, thioredoxin (TRX), an antioxidant protein, was also highly expressed in OSA tonsils at the mRNA and protein levels (p < 0.01). Thus, T cells are in a highly proliferative state in the tonsils of children with OSA and are associated with increased production of proinflammatory cytokines and TRX, when compared with children with RI.

Sleep duration and biomarkers of inflammation

INTRODUCTION

Extremes of sleep duration have been associated with adverse health outcomes. The mechanism is unclear but may be related to increased inflammation. We sought to assess the association between sleep duration and inflammatory biomarkers.

METHODS

A total of 614 individuals from the Cleveland Family Study completed questionnaires about sleep habits and underwent polysomnography. A morning fasting blood sample was assayed for 5 inflammatory cytokines.

RESULTS

In this cohort, mean (SD) habitual sleep duration based on self-report was 7.6 (1.6) h and mean sleep duration by polysomnography (PSG) on the night prior to blood sampling was 6.2 (1.3) h. After adjusting for obesity and apnea severity, each additional hour of habitual sleep duration was associated with an 8% increase in C-reactive protein (CRP) levels (P=0.004) and 7% increase in interleukin-6 (IL-6) levels (P=0.0003). These associations were independent of self-reported sleepiness. In contrast, PSG sleep duration was inversely associated with tumor necrosis factor alpha (TNFa) levels. For each hour reduction in sleep, TNFalpha levels increased by 8% on average (P=0.02). Sleep duration was not associated with IL-1 or IL-10.

CONCLUSIONS

Increases in habitual sleep durations are associated with elevations in CRP and IL-6 while reduced PSG sleep duration is associated with elevated TNFa levels. Activation of pro-inflammatory pathways may represent a mechanism by which extreme sleep habits affect health.

[Alteration of the immune function in children with obstruction sleep apnea hypopnea syndrome]

OBJECTIVE

To study the alteration of the immune function in children with obstructive sleep apnea hypopnea syndrome.

METHOD

The changes of the IgG, IgA, IgM, CD3, CD4 and CD8 levels in serum were observed and analyzed pre and post adenoidectomy and tonsillectomy.

RESULT

Post-operatively, the level of IgG, IgA, IgM, and the CD3, CD4 and CD8 in serum showed no evident alteration.

CONCLUSION

Adenoidectomy and tonsillectomy have no injury on the immune function of children with OSAHS.

[Peri-uvulopalatopharyngoplasty erythrocyte immune function analysis in patients with obstructive sleep apnea hypopnea syndrome]

OBJECTIVE

To investigate the effect of ECR I, RBC-C3bRR, RBC-ICR on obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHOD

Fifty-four inpatients with OSAHS and 20 healthy controls at the same age were enrolled. 1 ml fresh whole blood with stomach empty in early morning were collected before and after the surgery to detect ECR I , RBC-C3bRR and RBC-ICR.

RESULT

The erythrocyte immune function of the OSAHS group was lower than that of the control group.

CONCLUSION

Erythrocyte immune functional disorder plays an important role in OSAHS and surgical procedures is effective in correcting the changes.

Systemic inflammation in non-obese children with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) has been associated with increased systemic inflammatory responses that may contribute to an increased risk for end-organ morbidity. The changes in levels of pro-inflammatory cytokine IL-6 , and the anti-inflammatory cytokine IL-10, both of which play a major role in atherogenesis, a major consequence of OSA, have not specifically been assessed in pediatric patients.

METHODS

Consecutive non-obese children (aged 4-9years) who were polysomnographically diagnosed with OSA, and age-, gender-, ethnicity-, and BMI-matched control children underwent a blood draw the next morning after a sleep study and plasma samples were assayed for interleukins 6 (IL-6) and 10 (IL-10). These tests were repeated 4-6months after tonsillectomy and adenoidectomy (T&A) in children with OSA.

RESULTS

IL-6 levels were higher and IL-10 plasma levels were lower in children with OSA and returned to control levels after T&A.

CONCLUSIONS

Systemic inflammation is a constitutive component and consequence of OSA in many children, even in the absence of obesity, and is reversible upon treatment in most patients.

Inflammatory proteins in patients with obstructive sleep apnea with and without daytime sleepiness

Excessive daytime sleepiness (EDS) is one of the most frequent symptoms in patients with obstructive sleep apnea syndrome (OSAS). However, not all patients with OSAS manifest EDS. The aim of this study was to assess whether differential circulatory levels of inflammatory mediators would account for differences in somnolence among patients with OSAS. Patients were prospectively recruited from referral patient cohort to the university hospital sleep center. A total of 50 consecutive patients with OSAS undergoing overnight polysomnography with or without EDS and 20 controls were evaluated. EDS was assessed using the Epworth sleepiness scale (ESS) and the multiple sleep latency test after overnight polysomnography. EDS was defined when the ESS was >10 and the mean sleep latency <10 min. Fasting blood was drawn in the morning after polysomnography. Circulating levels of tumor necrosis factor alpha (TNFalpha), interleukin-6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), 8-isoprostaglandin F2alpha (8-iso-PGF2alpha), and P-selectin were measured with commercially available high sensitivity kits. Although patients with OSAS have elevated levels of ICAM-1, IL-6, and TNFalpha, there were no statistically significant differences in any of the inflammatory mediators between patients with EDS and without EDS. Emergence of EDS in the context of OSA does not appear to result from the selective increase of any particular somnogenic substance, i.e., TNFalpha, IL-6, ICAM-1, 8-iso-PGF2alpha, and P-selectin in the context of sleep-disordered breathing.

Evidence for activation of nuclear factor kappaB in obstructive sleep apnea

Obstructive sleep apnea (OSA) is a risk factor for atherosclerosis, and atherosclerosis evolves from activation of the inflammatory cascade. We propose that activation of the nuclear factor kappaB (NF-kappaB), a key transcription factor in the inflammatory cascade, occurs in OSA. Nine age-matched, nonsmoking, and non-hypertensive men with OSA symptoms and seven similar healthy subjects were recruited for standard polysomnography followed by the collection of blood samples for monocyte nuclear p65 concentrations (OSA and healthy groups). In the OSA group, p65 and of monocyte production of tumor necrosis factor alpha (TNF-alpha) were measured at the same time and after the next night of continuous positive airway pressure (CPAP). p65 Concentrations in the OSA group were significantly higher than in the control group [median, 0.037 ng/microl (interquartile range, 0.034 to 0.051) vs 0.019 ng/microl (interquartile range, 0.013 to 0.032); p = 0.008], and in the OSA group were significantly correlated with apnea-hypopnea index and time spent below an oxygen saturation of 90% (r = 0.77 and 0.88, respectively) after adjustment for age and BMI. One night of CPAP resulted in a reduction in p65 [to 0.020 ng/mul (interquartile range, 0.010 to 0.036), p = 0.04] and levels of TNF-alpha production in cultured monocytes [16.26 (interquartile range, 7.75 to 24.85) to 7.59 ng/ml (interquartile range, 5.19 to 12.95), p = 0.01]. NF-kappaB activation occurs with sleep-disordered breathing. Such activation of NF-kappaB may contribute to the pathogenesis of atherosclerosis in OSA patients.

C-reactive protein is associated with sleep disordered breathing independent of adiposity

STUDY OBJECTIVES

It is well established that medical conditions such as obesity and cardiovascular disease are associated with increased levels of inflammatory biomarkers such as C-reactive protein (CRP). Prior studies have produced inconsistent results regarding the association between sleep disordered breathing (SDB) and CRP, possibly due to the confounding effects of obesity or medical comorbidity. The present study examined the association between degree of SDB and level of CRP independent of prevalent medical conditions and obesity.

DESIGN

Cross-sectional study.

SUBJECTS AND SETTING

University-based clinical sample referred for diagnostic polysomnography.

MEASUREMENTS AND RESULTS

The study sample consisted of 69 men (mean age 40 years; mean BMI of 31.2 kg/m2) free of prevalent medical conditions including hypertension, diabetes mellitus, and cardiovascular disease. Measurements of morning and evening CRP levels were performed along with full-montage polysomnography. Confounding due to obesity was assessed by adjustments for body mass index, waist circumference, and percent body fat. A strong association was found between degree of SDB and serum levels of CRP, with or without adjustment for age and several measures of adiposity. Between the lowest and highest quartiles of apnea-hypopnea index (AHI) the mean difference in adjusted level of CRP was 3.88 microg/ml (P < 0.001). Moreover, an independent association between serum CRP levels and nocturnal hypoxia was also observed, whereas no association was noted with parameters of sleep architecture.

CONCLUSIONS

While more research is needed to elucidate causal pathways involving the effects of sleep-related hypoxia on low-grade systemic inflammation, the results of this study suggest that mechanisms other than adiposity per se could contribute to the inflammatory state seen in adults with SDB.

Hypoxemia and obesity modulate plasma C-reactive protein and interleukin-6 levels in sleep-disordered breathing

C-reactive protein (CRP) and interleukin-6 (IL-6) are pro-inflammatory proteins and important risk factors for atherosclerosis. Plasma CRP levels in snoring children may or may not be elevated. Since obesity is prevalent among snoring children and is associated with elevated CRP levels, we aimed to investigate the relative contributions of sleep-disordered breathing (SDB) and obesity to the inflammatory processes in snoring children in this prospective study. Two hundred forty-four children (mean age 8.9 +/- 3.4 years) underwent polysomnographic evaluation. CRP was measured the following morning, and plasma IL-6 levels from 111 randomly selected children were also examined. Plasma CRP and IL-6 levels were elevated in children with SDB. Log plasma CRP levels were higher in the moderate-severe SDB group (apnea/hypopnea index, AHI > or = 5) compared to the mild SDB group (AHI > or = 1 and <5; p < 0.0001) or the control group (AHI < 1; p = 0.0001). Log plasma CRP levels correlated with AHI, arousal index, relative BMI, and SpO(2) nadir (r = 0.30, p < 0.0001; r = 0.21, p = 0.002; r = 0.39, p < 0.0001, r = -0.36, p < 0.0001, respectively). Log plasma CRP levels were lower in children with SpO(2) nadir > or =90 (p < 0.0001). Sub-analysis of the 116 non-obese children in the cohort revealed similar findings. Log plasma IL-6 levels were increased in children with moderate-severe SDB compared to controls (p = 0.03) and correlated with AHI (r = 0.28, p = 0.003) and SpO(2) nadir (r = -0.24, p = 0.02). Children with SDB display significant severity-dependent increases in plasma CRP and IL-6 levels independent of obesity.

Lymphocyte activation as a possible measure of atherosclerotic risk in patients with sleep apnea

Obstructive sleep apnea (OSA), a breathing disorder in sleep characterized by intermittent hypoxia and sleep fragmentation, constitutes an independent risk factor for cardiovascular morbidity. Investigating how this breathing disorder modulates immune responses may facilitate understanding one of the risk factors for atherosclerosis. T cells play a significant role in atherogenesis and plaque development via cytokine production and by directly contributing to vascular injury. Using flow cytometry and chromium release assays, we found that CD4 and CD8 T cells of OSA patients undergo phenotypic and functional changes and acquire cytotoxic capabilities. Thus, a shift in CD4 and CD8 T cells toward type 2 cytokine dominance with increased IL-4 expression was noted. IL-10 expression in T cells was negatively correlated with the severity of OSA, as determined by the apnea-hypopnea index (AHI), whereas TNF-alpha was positively correlated. CD8 T cells of OSA patients expressed a fourfold increase in TNF-alpha and CD40 ligand (CD40L), and exhibited an increased OSA severity-dependent cytotoxicity against endothelial cells. The percentage of CD4(+)CD28(null) and cytotoxicity of CD4 T lymphocytes were also significantly higher in OSA patients than in controls. Nasal continuous positive airway pressure (nCPAP) treatment, which ameliorated the severity of OSA, significantly lowered TNF-alpha and CD40L expression, and decreased cytotoxicity in CD8 T cells. In conclusion, increased cytotoxicity and cytokine imbalance in CD4 and CD8 T cells may be involved in atherogenesis in OSA. Nasal CPAP treatment ameliorates some lymphocyte dysfunctions and thus may moderate some atherogenic pathways.

Increased carotid intima-media thickness and serum inflammatory markers in obstructive sleep apnea

Increased carotid intima-media thickness (IMT) and increased serum levels of inflammatory markers, such as C-reactive protein (CRP), interleukin (IL)-6, and IL-18, are associated with an increased risk of cardiovascular and cerebrovascular diseases. The aim of this study was to evaluate whether carotid IMT, a useful marker for early atherosclerosis, is associated with these inflammatory markers in patients with obstructive sleep apnea (OSA). Carotid IMT was investigated with ultrasonography in 36 patients with OSA and 16 obese control subjects. Serum levels of CRP, IL-6, and IL-18 were measured at 5:00 A.M. Carotid IMT (p < 0.001) and serum levels of CRP (p < 0.003), IL-6 (p < 0.005), and IL-18 (p < 0.03) of patients with OSA were significantly higher than those of obese control subjects. Carotid IMT was significantly correlated with serum levels of CRP (r = 0.61, p = 0.0001), IL-6 (r = 0.41, p = 0.01), and IL-18 (r = 0.45, p = 0.005), duration of OSA-related hypoxia (r = 0.60, p = 0.0001), and severity of OSA (r = 0.50, p = 0.002). In addition, the primary factor influencing carotid IMT was duration of hypoxia during total sleep time (p = 0.036). These results suggest that OSA-related hypoxia and systemic inflammation might be associated with the progression of atherosclerosis and thus might increase the risks of cardiovascular and cerebrovascular morbidity in patients with OSA.

The relationship between serum cytokine levels with obesity and obstructive sleep apnea syndrome

Inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) may have a direct effect on glucose and lipid metabolism. On the other hand, it is known that IL-6 and TNF-alpha are important pro-inflammatory cytokines in the pathogenesis of atherosclerosis. The goal of present study was to test whether sleep apnea contributes to the previously reported increases of IL-6 and TNF-alpha independent of obesity. Forty-three obese (body mass index, BMI>27 kg/m2) men with newly diagnosed obstructive sleep apnea syndrome (OSAS) (apnea-hypopnea index, AHI> or =5) and age- and BMI-matched 22 obese nonapneic male controls (AHI<5) were enrolled in this study. To confirm the diagnosis, all patients underwent standard polysomnography in the sleep disorders center. Serum samples were taken at 08:00 h in the morning after overnight fasting. Serum IL-6 and TNF-alpha levels were found significantly higher in OSAS patients than in controls (p=0.002, p=0.03). Serum IL-6 and TNF-alpha levels were significantly correlated with AHI in OSAS patients (r=0.03, p=0.046 and r=0.36, p=0.016). There was no significant correlation between serum IL-6, TNF-alpha levels and AHI in controls. Serum IL-6 and TNF-alpha levels were not correlated with BMI both in OSAS patients and controls. In conclusion, circulating IL-6 and TNF-alpha levels in patients with OSAS, as independent of BMI are significantly higher than levels in controls and there is a positive relationship between previously mentioned cytokines' levels and the severity of OSAS. According to these results, the link between cardiovascular morbidity and OSAS may be explained by the coexistence of other cardiovascular risk factors such as circulating IL-6 and TNF-alpha levels.

Nasal cytology: a marker of clinically silent inflammation in patients with obstructive sleep apnea and a predictor of noncompliance with nasal CPAP therapy

STUDY OBJECTIVES

Patients with obstructive sleep apnea treated with nasal continuous positive airway pressure (CPAP) often complain of nasal side effects. We studied patients before and after initiation of nasal CPAP to see how treatment affected nasal function and markers of nasal inflammation. We searched for pretreatment findings that might help to predict noncompliance.

METHODS

Nasal symptom scores, nasal flow by anterior rhinomanometry, mediator levels (intercellular adhesion molecule-1, interleukin-6, interleukin-8 and interleukin-13), and nasal scrapes for cytology were obtained at baseline and monthly for up to 3 months of nasal CPAP therapy. Compliance was assessed from the patient's report and by recording hours of usage for up to 19 months of follow-up.

RESULTS

Thirty-eight patients with newly diagnosed obstructive sleep apnea were classified as having no rhinitis (42%), allergic rhinitis (37%), or nonallergic rhinitis (21%). There was no significant difference in compliance in patients with and without rhinitis. Compliant and noncompliant patients showed no significant differences in their baseline nasal symptom scores, nasal flow, and mediator levels. Nasal neutrophil counts before treatment were greater in noncompliant than in compliant patients (p = .004) and greater in those discontinuing because of nasal symptoms than in patients who quit for other reasons (p = .05). There was a positive correlation between neutrophil counts and nasal bacterial scores, both before and after treatment with nasal CPAP.

CONCLUSIONS

Patients with increased neutrophil counts in the nasal scrape before beginning nasal CPAP are at increased risk of discontinuing therapy. They appear to have subclinical nasal inflammation that cannot be identified from clinical assessment, nasal symptom scores or rhinomanometry.

Activated CD8+ T-lymphocytes in obstructive sleep apnoea

T-lymphocytes are implicated in the development of atherosclerosis. The aim of this study was to assess whether the CD8+ T-lymphocytes of obstructive sleep apnoea (OSA) patients undergo phenotypic and functional changes that may exaggerate atherogenic sequelae in OSA. A total of 36 OSA patients, 17 controls and 15 single-night-treated OSA patients were studied. Phenotype and cytotoxicity against K562 target cells were analysed by flow cytometry. Cytotoxicity against human umbilical vein endothelial cells (HUVECs) was assessed by 51Cr release assay. The cytotoxicity of the CD8+ T-lymphocytes of OSA patients against K562 and HUVECs was significantly greater than controls. This increased cytotoxicity directly depended on the presence of perforin and natural killer receptors (CD56, CD16), which were significantly increased in OSA CD8+ T-lymphocytes. Also the percentage of the CD56bright subset, which mediates initial interactions with vascular endothelium, significantly increased in OSA. Nasal continuous positive airway pressure treatment significantly decreased CD8+ T-cell cytotoxicity and CD56 expression, and was positively correlated with natural killer inhibitory NKB1 receptor expression either after a single-night treatment or after a prolonged treatment. In conclusion, the CD8+ T-lymphocytes of obstructive sleep apnoea patients undergo phenotypic and functional changes, rendering them cytotoxic to target cells via increased CD56+/perforin+ expression, which can be ameliorated by nasal continuous positive airway pressure treatment. These results are compatible with the current authors' hypothesis of atherogenic sequelae in obstructive sleep apnoea.

Resistin levels in patients with obstructive sleep apnoea syndrome--the link to subclinical inflammation?

BACKGROUND

The role of resistin, a "new" white adipose tissue hormone, still needs to be established. Its linkage to insulin sensitivity and body mass was controversial in previous studies.

MATERIAL/METHODS

Twenty obese patients (BMI: 32.1+/-6.9 kg/m2 ) with obstructive sleep apnoea syndrome (OSAS) (Apnoea-Hypopnoea Index: 48.6+/-19.1, underwent measurements of resistin, interleukin-6 (IL-6), intracellular adhesion molecule-1 (ICAM-1), CRP and the insulin sensitivity index (ISI) by hyperinsulinaemic euglycaemic clamp before, 2 days and 2 months after onset of CPAP treatment.

RESULTS

Resistin remained unchanged during CPAP-therapy and was negatively correlated to ISI (r=-0.359; p=0.006), the latter was significantly improved by CPAP (p<0.001). In a correlation matrix, IL-6 and ICAM-1 were significantly (p=0.001) correlated to resistin (p=0.614 and 0.427). Changes of inflammatory markers under CPAP treatment were related to AHI, as well as resistin changes.

CONCLUSIONS

In agreement with previous investigations, we could only demonstrate a weak linkage between ISI and resistin. However, at least in obese patients with OSAS, there is a close relation to subclinical inflammation (IL-6) and endothelial activation (ICAM-1).

[T cell immunity analysis in children with obstructive sleep apnea syndrome]

OBJECTIVE

To probe into the possible impact on T cell immunity in children with obstructive sleep apnea syndrome (OSAS).

METHOD

Lymphocytes in peripheral blood vessel of children with OSAS vs normal controls were checked by APAAP method and analyzed statistically.

RESULT

The comparison with the controls showed that CD3+ had no significant difference (P>0.05), CD4+, CD4+/CD8+ were significantly lower, CD8+ was significantly higher in children with OSAS (P<0.01), and the analysis of the LSaO2 and period of history showed that the lower the LSaO2, and the longer the period of history, the more effect to CD4+, CD8+, CD3+/CD8+ (P<0.05).

CONCLUSION

T cell immunity are impaired in children with OSAS.

Differential gene expression in the T-helper lymphocytes of obstructive sleep apnea patients treated with nasal continuous positive airway pressure (nCPAP)

Obstructive sleep apnea (OSA) is a disease with significant morbidity, increased risk of accidents attributed to daytime somnolence, and has been associated with cardiovascular complications. The treatment of choice for OSA is nasal continuous positive airway pressure (nCPAP). Some OSA patients, however, are unable to benefit from this therapy as they find nCPAP intolerable due to the related nasal inflammation. It is hypothesized that nCPAP may cause nasal inflammation in these patients by inducing changes in the expression of genes that encode interleukins (IL-3, IL-4, IL-6, IL-8, IL-13) or adhesion molecules (i.e., ICAM-1) in T-helper lymphocytes. An understanding of the underlying inflammatory mechanism could lead to specific interventions that render nCPAP therapy tolerable for these individuals.

Sleep apnea: a model for studying cytokines, sleep, and sleep disruption

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder, characterized by repeated disruptions of breathing during sleep. The sleep fragmentation and accompanying hypoxemia lead to many negative consequences including cardiac arrhythmias, nocturnal hypertension, confusion, cognitive impairment, daytime sleepiness, as well as depressive symptoms. From the perspective of psychoneuroimmunology (PNI), OSA holds promise as a model for studying sleep and cytokines because of its many relevant characteristics, including neuroimmune interactions, mood changes, and behaviors that directly affect the course of the disorder. In this minireview we briefly summarize the existing literature on cytokines and sleep and then discuss work on cytokines and OSA. We believe that the study of OSA presents researchers with an excellent opportunity to tease apart the many complex and interwoven components of sleep that are relevant to PNI.

Inflammation and obstructive sleep apnea syndrome pathogenesis: a working hypothesis

Obstructive sleep apnea syndrome (OSAS) afflicts about 5% of adults in Western countries and is thought to play an important role in the pathogenesis of cardiovascular disorders and diabetes mellitus. Although the etiology of OSAS is uncertain, intense local and systemic inflammation are present in these patients. In the upper airway, this process may promote oropharyngeal inspiratory muscle dysfunction and amplify upper airway narrowing and collapsibility thereby worsening the frequency and duration of apneas during sleep. The presence of systemic inflammation, characterized by elevated levels of certain potent pro-inflammatory mediators, such as C-reactive protein, leptin, TNF-alpha, IL-1beta, IL-6, reactive oxygen species and adhesion molecules, may predispose to the development of cardiovascular complications observed in patients with OSAS. Treatment with nasal CPAP abrogates, in part, local and systemic inflammation in these patients. Whether therapeutic interventions aimed at abating inflammation could be a useful adjunct in the treatment of OSAS merits further investigation.

The Effect of Surgical Treatment of Obstructive Sleep Apnea Syndrome on the Plasma TNF-.ALPHA. Levels

Obstructive sleep apnea syndrome (OSAS) is defined as intermittent complete or partial upper airway obstruction during sleep, causing mental and physical effects. Both the local and systemic inflammation observed in OSAS induce certain potent pro-inflammatory mediators, which may contribute to the development of cardiovascular consequences. The present study was designed to evaluate the plasma levels of TNF-alpha, which is one of the known pro-inflammatory cytokines, in patients with OSAS and to assess the effect of surgical treatment on the levels of TNF-alpha levels. Twenty seven patients diagnosed to have OSAS, 7 non-apneic patients with chronic tonsillitis (non-OSAS patients), and 4 healthy subjects were enrolled in this study. Blood samples were collected one week preoperatively and postoperatively, and the plasma TNF-alpha levels were measured using high-sensitivity ELISA. The plasma TNF-alpha levels in patients with OSAS were significantly elevated in comparison to normal healthy subjects. In contrast, there was no difference between the patients with non-OSAS and healthy subjects. Moreover, the surgical treatment to enlarge the upper airway in patients with OSAS significantly decreased the levels of TNF-alpha levels. Surgical treatment of patients with OSAS reduces the plasma TNF-alpha levels, thereby ameliorating the systemic inflammation and preventing the development of cardiovascular consequences.

Plasma cytokine levels in patients with obstructive sleep apnea syndrome: a preliminary study

The levels of some pro- and anti-inflammatory cytokines [interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, IL-6, IL-10, and transforming growth factor (TGF)-beta], were measured by enzyme-linked immunosorbent assay (ELISA) method in the plasma of patients affected by obstructive sleep apnea syndrome (OSAS) at 22:00 hours before polysomnographic recording and immediately after the first obstructive apnea causing an SaO2 below 85%. Significantly higher levels of TNF-alpha were found in OSAS patients assessed before polysomnography compared with the control group (P < 0.01). A slight but significant increase in the plasma levels of IL-6 was also present (P < 0.05). Conversely, a significant decrease in the plasma levels of IL-10 was evident at baseline in OSAS patients (P < 0.04). No significant difference emerged between the mean values of IL-1alpha and TGF-beta between OSAS patients and controls. The present data support a prevailing activation of the Th1-type cytokine pattern in OSAS patients, which is not associated with the severity and duration of OSAS. This can have important consequences for the outcome of OSAS patients, especially with regard to the increased risk for developing atherosclerosis and cardiovascular and cerebrovascular diseases. Immediately after the first obstructive apnea causing an SaO2 <85%, a significant variation was observed in the plasma levels of TNF-alpha in OSAS patients compared with those measured before the beginning of polysomnographic recording (P < 0.001). The role played by this further increase in TNF-alpha levels after the obstructive apnea in OSAS patients remains to be established in the light of the pathogenic mechanisms of this sleep disorder.