Lung clearance index: evidence for use in clinical trials in cystic fibrosis

The ECFS-CTN Standardisation Committee has undertaken this review of lung clearance index as part of the group's work on evaluation of clinical endpoints with regard to their use in multicentre clinical trials in CF. The aims were 1) to review the literature on reliability, validity and responsiveness of LCI in patients with CF, 2) to gain consensus of the group on feasibility of LCI and 3) to gain consensus on answers to key questions regarding the promotion of LCI to surrogate endpoint status. It was concluded that LCI has an attractive feasibility and clinimetric properties profile and is particularly indicated for multicentre trials in young children with CF and patients with early or mild CF lung disease. This is the first article to collate the literature in this manner and support the use of LCI in clinical trials in CF.

Reference ranges and cutoff levels of pneumococcal antibody global serum assays (IgG and IgG2) and specific antibodies in healthy children and adults

Pneumococcal antibodies represent the acquisition of natural immunity. Determination of pneumococcal antibodies is an important screening tool for immunodeficiencies. Our study generated reference ranges and cutoff levels for pneumococcal antibody global serum assays correlated to a specific pneumococcal antibody ELISA. Specific pneumococcal antibody levels were measured from 457 children undergoing elective surgery and 46 healthy adult volunteers (88 with previous pneumococcal immunization from both groups), 22 severe immunodeficient subjects with ataxia telangiectasia (A-T, negative controls), and age-matched 36 healthy allergic asthmatics. We determined a representative panel of serotype-specific pneumococcal antibodies (serotype 4, 5, 6B, 7F, 14, 18C, 19F, 23F) by ELISA and global pneumococcal IgG and IgG2 antibodies by EIA. In vaccine-naïve healthy subjects, initial pneumococcal IgG geometric mean concentrations of 13.1 μg/ml were low in the first year of life and increased over the time, reaching adult levels (70.5 μg/ml) at age 8-12 years. In parallel, IgG2 antibodies increased from 20.7 % (0.5-1 year old) to adult proportions (>30 %) in preschoolers. Correlation between the pneumococcal IgG screening assay and specific pneumococcal antibody levels was acceptable (Pearson's coefficient r = 0.4455; p = 0.001). Cutoff levels showed high sensitivity, whereas specificity was high to moderate calculated from correlations with the specific ELISA. We provide reference ranges and cutoff levels for the interpretation of specific antibody determinations in the clinical setting. The global pneumococcal IgG/IgG2 assay is a suitable screening tool and correlates with the ELISA serotype-specific pneumococcal antibodies. However, results below our cutoff values should be re-evaluated by serotype-specific ELISA testing.

[Quality of life for adolescents with vocal cord dysfunction]

BACKGROUND

Vocal cord dysfunction (VCD) is a functional breathing disorder. A psychosomatic aetiology has been discussed and associations with depression, anxiety disorders, and social stress have been reported. We have undertaken a screening of behavioural and emotional problems in adolescent patients using standardised questionnaires.

METHODS

Thirty-one patients (8 - 16 years) with the clinical suspicion of VCD were investigated using the Youth-Self-Report (YSR/11 - 18) and for the assessment of the parents we used the analoguous Child-Behaviour-Checklist (CBCL/6 - 18). YSR and CBCL contain two sub-areas: (a) competence scales that measure the child's participation in activities, social skills and school achievements and (b) items that contain subscales for emotional problems such as depressive and anxiety symptoms, conduct problems such as oppositional defiant problems and aggressive behaviour, social problems and physical complaints.

RESULTS

On average, the features of VCD patients were not significantly different from those of the reference population. But we did observe tendencies of psychological problems (YSR 16.7 %, CBCL 20 %) compared with the standard (2 %) in the syndrome scales of both questionnaires Adolescents reported particularly more internalising disorders such as social retreat, physical complaint and anxiety and depressive symptoms. The parents reported more often "physical complaints" (13.3 %) and "aggressive behaviour" (10 %).

CONCLUSIONS

We found tendencies of psychological strain, mainly social retreat, physical complaints and anxiety and depressive symptoms. Further investigations should focus on those emotional problems as well as on psychosomatically caused physical problems. Personality and psychological stress of the parents should be included in the investigation in order to evaluate the reports of the parents on higher aggressive behaviour and enhanced physical problems of their children in relation to their own psychological strain. We suggest family therapies, family counselling, or parental coaching as a therapeutic approach.

[Lung function testing in children before and after an age-adapted SCUBA dive in a swimming pool]

BACKGROUND

The number of children that SCUBA dive is increasing. Airway narrowing while SCUBA diving can cause dangerous complications like pulmonary barotrauma and arterial gas embolism. Statistics show that children are at an increased risk. Since data are scarce, the goal of this study was to gain new knowledge about acute lung function changes in children while SCUBA diving.

MATERIAL AND METHODS

41 children aged 8 - 14 years underwent lung function testing (spirometry and residual volume measurement) before and after a single age-adapted SCUBA dive in a swimming pool.

RESULTS

A significant reduction of the dynamic expiratory lung function parameters FEV (1) (p < 0.01), FEV (1)/VC (p < 0.05), MEF 75 % (p < 0.05), MEF 50 % (p < 0.01) und MEF 25 % (p < 0.05) was measured. No statistically significant change of the residual volume was found. A decrease of FEV (1) > 10 % (12 % - 21 %) was found in 5 children (12.2 %).

CONCLUSION

The majority of the children (87.8 %) did not show any relevant lung function changes. Five children had a considerable reduction of FEV (1). Signs indicate the importance of bronchial hyperreactivity (BHR) as a key factor. Children with asthma or BHR should not SCUBA dive. A detailed medical examination is recommended (including an unspecific bronchial provocation test) before starting to dive.

[Pro-resolving lipid mediators in inflammatory lung diseases]

Uncontrolled inflammation of the lung contributes to the major medical and economic burden on healthcare, and the need for therapeutics to dampen pathological inflammation is largely unmet. Recently, a new genus of anti-inflammatory/ pro-resolving lipid mediators has been identified: Lipoxins, resolvins, protectins and maresins. These compounds are enzymatically derived from the polyunsaturated fatty acids (PUFAs) arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) that have long been known to have beneficial health properties. These mediators have potent anti-inflammatory effects IN VITRO and IN VIVO in murine models of lung inflammation. Therefore, this group of compounds carries considerable therapeutic potential for the treatment of many inflammatory lung diseases including asthma, cystic fibrosis and acute lung injury.

[The repeatability of forced expiratory manoeuvres in 4- to 6-year-old children with intermittent bronchial asthma in healthy and in exacerbated status]

INTRODUCTION

The question about the repeatability of forced expiratory manoeuvres in childhood lung function testing is of scientific and clinical interest. The following study investigated to what extent children ≥ 4 to < 7 years of age with intermittent bronchial asthma are able to produce reproducible lung function measurements on the one hand in the healthy status and on the other hand in an exacerbated status.

METHOD

64 children at the age of ≥ 4 to < 7 years with intermittent preschool bronchial asthma performed lung function measurements in the healthy status and again in an exacerbated status. FEV (1) values from the measurements were analysed according to ATS/ERS guidelines concerning repeatability.

RESULTS

According to the new ATS/ERS guidelines 74.6 % of the children could perform at least 2, and 59.3 % could perform 3 repeatable measurements in the healthy status. In the exacerbated status this was 87.5 % and 68.8 %, respectively. There were no significant differences between the healthy and the exacerbated status and between the age groups. Compared to former repeatability criteria, children of this age group can perform significantly more reproducible measurements (p < 0.0001).

CONCLUSION

The ATS/ERS guidelines from 2007 simplify the repeatability of forced expiratory manoeuvres in children at ≥ 4 to < 7 years of age compared to the former criteria. Repeatability is not reduced in the exacerbated status. 74.6 % of children in this age group can produce repeatable lung function measurements.

Efficacy of probiotic Lactobacillus GG on allergic sensitization and asthma in infants at risk

BACKGROUND

Probiotics are perceived to exert beneficial effects in the prevention and treatment of allergic diseases.

OBJECTIVE

There are conflicting data from studies as to an impact on allergic sensitization and asthma.

METHODS

Our prospective double-blind study randomly assigned 131 children (6-24 months old) with at least two wheezing episodes and a first-degree family history of atopic disease to 6 months of Lactobacillus rhamnosus (LGG, 10(10) colony forming units) or placebo. Atopic dermatitis and asthma-related events (e.g. need of inhalation, symptom-free days) were documented throughout the intervention and 6-month follow-up. We determined IgE, a representative panel of specific IgE, eosinophils, eosinophilic cationic protein, and TGF-beta before, at the end of intervention, and after 6 months of follow-up.

RESULTS

There were no significant differences as to atopic dermatitis or asthma-related events. In a subgroup with antecedent allergic sensitizations, asthmatic complaints were even slightly worse. We found fewer sensitizations towards aeroallergens after 6 months of LGG (P=0.027) and after 6 months of follow-up (P=0.03). Supplementation was well-tolerated and no severe adverse events occurred.

CONCLUSIONS

In young children with recurrent wheeze and an atopic family history, oral LGG had no clinical effect on atopic dermatitis or asthma-related events, and only mild effects on allergic sensitization. This effect persisted 6 months after the cessation of the supplementation.

Tolerance induction after specific immunotherapy with pollen allergoids adjuvanted by monophosphoryl lipid A in children

Specific immunotherapy (SIT) is a well-established and clinically effective treatment for allergic diseases. A pollen allergoid formulated with the T helper type 1 (Th1)-inducing adjuvant monophosphoryl lipid A (MPL) facilitates short-term SIT. Little is known about mechanisms of tolerance induction in this setting. In a prospective study, 34 patients allergic to grass pollen (25 male, nine female, median age 10.2 years) received a total of 44 SIT courses (20 in the first, 24 in the second) with MPL-adjuvanted pollen allergoids. Immunogenicity was measured by levels of specific immunoglobulin G (IgG(grass)) and IgG4(grass) by antibody blocking properties on basophil activation, and by induction of CD4(+), CD25(+) and forkhead box P3 (FoxP3(+)) regulatory T cells (T(reg)). Specific IgG and IgG4 levels increased only slightly in the first year of SIT. In the second year these changes reached significance (P < 0.0001). In keeping with these findings, we were able to show an increase of T(reg) cells and a decreased release of leukotrienes after the second year of treatment. In the first year of treatment we found little evidence for immunological changes. A significant antibody induction was seen only after the second course of SIT. Short-course immunotherapy with pollen allergoids formulated with the Th1-inducing adjuvant MPL needs at least two courses to establish tolerance.

Effect of n-3 polyunsaturated fatty acids in asthma after low-dose allergen challenge

BACKGROUND

We investigated the anti-inflammatory potential of n-3 polyunsaturated fatty acids (PUFA) on specific bronchial inflammation. Allergic asthmatics were challenged using a low-dose allergen provocation model.

METHODS

Our parallel double-blinded study randomly assigned 23 house dust mite-allergic asthmatics (aged 22-29 years; 13 females, 10 males) to dietary supplementation with either an n-3 PUFA-enriched fat blend (0.69 g/day) or placebo for 5 weeks. After 3 weeks, the patients were challenged daily with low doses of mite allergen for 2 weeks. Primary outcome parameters were effects on lung function (forced expiratory volume in 1 s, FEV(1)) and exhaled nitric oxide (eNO) as a marker of bronchial inflammation.

RESULTS

Even before the bronchial challenge, eNO was significantly lower in the n-3 PUFA group (p=0.014). Levels of eNO increased during allergen exposure in both groups, but differences in means were significantly lower in the n-3 PUFA group (p=0.022). During the low-dose allergen challenge, there were no differences between the groups with regard to symptoms, FEV(1) or the allergen dose required to induce deterioration of lung function (PD(20)). Numbers of sputum eosinophils did not differ significantly, while serum eosinophils (10.1+/-0.1.84 vs. 5.79+/-0.69%) as well as changes in eosinophilic cationic protein (20.5+/-9.93 vs. -1.68+/-4.36 ng/ml) and in vitro cysteinyl leukotriene release (2,889+/-872 vs. 1,120+/-173 ng/ml) were significantly lower in the n-3 PUFA group (p<0.05 each).

CONCLUSION

Our results provide evidence that dietary supplementation with n-3 PUFA is able to reduce bronchial inflammation even after low-dose allergen challenge.

Safety and immunogenicity of a cluster specific immunotherapy in children with bronchial asthma and mite allergy

BACKGROUND

Cluster specific immunotherapy (SIT) is a modern form of allergen immunotherapy allowing safe administration of high allergen doses in a short time interval compared to classic SIT. In the current study, we investigated the safety profile and immunological effect of cluster SIT in children with allergic asthma due to house dust mite allergy.

METHODS

A total of 34 children (6-18 years) with allergic asthma were assigned to cluster (n = 22) or classic SIT (n = 12). To achieve a maintenance dose of allergen extract, cluster patients received 14 injections of house dust mite allergen within 6 weeks, whereas the classic SIT group received 14 injections within 14 weeks. Safety was monitored by recording adverse events. Immunogenicity was measured by specific IgG(Mite) and IgG4(Mite), by antibody-blocking properties on basophil activation, and by the T cell subset transcription factors Foxp3, T-bet, and GATA-3.

RESULTS

There were no significant differences in local and systemic side effects between the two groups. In the cluster group, serum levels of specific IgG(Mite) (p < 0.001) and specific IgG4(Mite) (p < 0.001) significantly increased after 8 weeks, while it took 12 weeks in the classic SIT group. These data were confirmed by blocking CD63 expression as well as release of cysteinyl leukotrienes after in vitro basophil stimulation. No differences in transcription factor expression were found in the two groups.

CONCLUSION

Cluster SIT is safe in children. Additionally, our data demonstrated an even more rapid induction of specific immune tolerance. Cluster SIT is an attractive alternative to conventional up-dosing schedules with fewer consultations for the patients.

Specific IgE serum concentration is associated with symptom severity in children with seasonal allergic rhinitis

BACKGROUND

The impact of allergen-specific and total IgE serum levels before and during the pollen season on symptom severity as well as efficacy of treatment with anti-IgE requires further delineation.

METHODS

Birch and grass pollen allergic patients aged 6-17 years with seasonal allergic rhinitis (SAR) were analyzed for the association of IgE serum concentration with symptom severity and rescue medication use (combination: symptom load, SL) during the grass pollen season. Reference group A (n = 53) received placebo, while group B (n = 54) received Omalizumab (anti-IgE) monotherapy before and during the grass pollen season.

RESULTS

Patients on placebo with high baseline specific grass pollen IgE (>50 kU/l) had a significantly higher SL compared with those with low IgE levels (< or =50 kU/l): SL 1.28 vs 0.61, P = 0.015. This association was nonexistent in patients treated with anti-IgE. In contrast, baseline total IgE levels did not correlate with SL in any group. Patients with anti-IgE treatment and high free total IgE levels (>16.7 ng/ml) had a significantly higher SL compared with those with low free total IgE levels (< or =16.7 ng/ml): SL 0.63 vs 0.23, P = 0.031.

CONCLUSIONS

Baseline specific IgE, but not total IgE, is associated with symptom severity during the pollen season in children with SAR. Likewise, the symptom load in SAR patients with anti-IgE correlates with free total IgE levels. Although further research in larger populations is needed to confirm our findings, our data suggest that specific IgE can be used as a parameter for patient selection for this kind of treatment.

[Effects of active and passive smoking on the health of children and adolescents]

Tobacco abuse is especially a public health problem among children and teenagers in Germany. While the proportion of adolescents smoking regularly was 18% in 1997, this has increased to more than 30% in 2001. The high impact of peer groups in young people aggravates the development of smoking habits. Furthermore, an addiction to nicotine develops mainly before the age of 20 (80% of all adults smokers have started as teenagers). Early and continued damage to health will result in long-term sequelae due to immaturity of the organs. Fortunately, the proportion of smoking adolescents has decreased in the last few years. Besides the well known effects of active smoking, children are especially endangered by environmental tobacco smoke (ETS). Exposure to cigarette smoke during pregnancy is directly correlated to premature rupture of the membranes, premature birth, delayed foetal development, and reduced lung function. Children are suffering from impairments of their health not only due to ETS exposure in utero but also after birth (e. g., diseases of upper and lower airways, delayed physical and mental development). Therefore, the prevention of active and passive smoking must be intensified and should consider the special situation of children and adolescents.