Tracheostomy decannulation in children: a proposal for a structured approach on behalf of the working group chronic respiratory insufficiency within the German-speaking society of pediatric pulmonology

The number of children with tracheostomies with and without home mechanical ventilation has grown continuously in recent years. For some of these children, the need for tracheostomy resolves and the child can be weaned from the tracheal cannula. Choosing the optimal time point for decannulation after elaborated prior diagnostic work-up needs careful consideration. The decannulation process requires an interdisciplinary team; however, these specialized structures for the experienced care of these children with tracheostomy are not available in all areas. The Working Group on Chronic Respiratory Insufficiency in the German Speaking Pediatric Pneumology Society (GPP) developed these recommendations to guide through a decannulation process. Initial evaluation of decannulation feasibility starts in the outpatient clinic with a detailed history, examination, and a speaking valve trial and is followed by an inpatient workup including sleep study, airway endoscopy and possibly modifications of the tracheal cannula. Downsizing the tracheal cannula allows a stepwise controlled weaning prior to removal of the tracheal cannula. After shrinking of the tracheostomy, the final surgical closure is performed.  Conclusion: An algorithm with diagnostic and therapeutic procedures for a safe and successful decannulation process is proposed. What is Known: • In children tracheostomy decannulation is a complex process that requires careful preparation and surveillance. What is New: • This statement of the German speaking society of pediatric pulmonology provides an expert practice guidance on the decannulation procedure and the value of one-way speaking valves.

Predicting food allergy: The value of patient history reinforced

Background

EAACI guidelines emphasize the importance of patient history in diagnosing food allergy (FA) and the need for studies investigating its value using standardized allergy‐focused questionnaires.

Objective

To determine the contribution of reaction characteristics, allergic comorbidities and demographics to prediction of FA in individuals experiencing food‐related adverse reactions.

Methods

Adult and school‐age participants in the standardized EuroPrevall population surveys, with self‐reported FA, were included. Penalized multivariable regression was used to assess the association of patient history determinants with “probable” FA, defined as a food‐specific case history supported by relevant IgE sensitization.

Results

In adults (N = 844), reproducibility of reaction (OR 1.35 [95% CI 1.29‐1.41]), oral allergy symptoms (OAS) (4.46 [4.19‐4.75]), allergic rhinitis (AR) comorbidity (2.82 [2.68‐2.95]), asthma comorbidity (1.38 [1.30‐1.46]) and male sex (1.50 [1.41‐1.59]) were positively associated with probable FA. Gastrointestinal symptoms (0.88 [0.85‐0.91]) made probable FA less likely. The AUC of a model combining all selected predictors was 0.85 after cross‐validation. In children (N = 670), OAS (2.26 [2.09‐2.44]) and AR comorbidity (1.47 [CI 1.39‐1.55]) contributed most to prediction of probable FA, with a combined cross‐validation‐based AUC of 0.73. When focusing on plant foods, the dominant source of FA in adults, the pediatric model also included gastrointestinal symptoms (inverse association), and the AUC increased to 0.81.

Conclusions

In both adults and school‐age children from the general population, reporting of OAS and of AR comorbidity appear to be the strongest predictors of probable FA. Patient history particularly allows for good discrimination between presence and absence of probable plant FA.

Predictors of Food Sensitization in Children and Adults Across Europe

BACKGROUND

The geographical variation and temporal increase in the prevalence of food sensitization (FS) suggest environmental influences.

OBJECTIVE

To investigate how environment, infant diet, and demographic characteristics, are associated with FS in children and adults, focusing on early-life exposures.

METHODS

Data on childhood and adult environmental exposures (including, among others, sibship size, day care, pets, farm environment, and smoking), infant diet (including breast-feeding and timing of introduction to infant formula and solids), and demographic characteristics were collected from 2196 school-age children and 2185 adults completing an extensive questionnaire and blood sampling in the cross-sectional pan-European EuroPrevall project. Multivariable logistic regression was applied to determine associations between the predictor variables and sensitization to foods commonly implicated in food allergy (specific IgE ≥0.35 kU_A/L). Secondary outcomes were inhalant sensitization and primary (non-cross-reactive) FS.

RESULTS

Dog ownership in early childhood was inversely associated with childhood FS (odds ratio, 0.65; 95% CI, 0.48-0.90), as was higher gestational age at delivery (odds ratio, 0.93 [95% CI, 0.87-0.99] per week increase in age). Lower age and male sex were associated with a higher prevalence of adult FS (odds ratio, 0.97 [95% CI, 0.96-0.98] per year increase in age, and 1.39 [95% CI, 1.12-1.71] for male sex). No statistically significant associations were found between other evaluated environmental determinants and childhood or adult FS, nor between infant diet and childhood FS, although early introduction of solids did show a trend toward prevention of FS.

CONCLUSIONS

Dog ownership seems to protect against childhood FS, but independent effects of other currently conceived environmental and infant dietary determinants on FS in childhood or adulthood could not be confirmed.

Prevalence of Food Sensitization and Food Allergy in Children Across Europe

BACKGROUND

For adults, prevalence estimates of food sensitization (FS) and food allergy (FA) have been obtained in a standardized manner across Europe. For children, such estimates are lacking.

OBJECTIVES

To determine the prevalence of self-reported FA, FS, probable FA (symptoms plus IgE sensitization), and challenge-confirmed FA in European school-age children.

METHODS

Data on self-reported FA were collected through a screening questionnaire sent to a random sample of the general population of 7- to 10-year-old children in 8 European centers in phase I of the EuroPrevall study. Data on FS and probable FA were obtained in phase II, comprising an extensive questionnaire on reactions to 24 commonly implicated foods, and serology testing. Food challenge was performed in phase III.

RESULTS

Prevalence (95% CI) of self-reported FA ranged from 6.5% (5.4-7.6) in Athens to 24.6% (22.8-26.5) in Lodz; prevalence of FS ranged from 11.0% (9.7-12.3) in Reykjavik to 28.7% (26.9-30.6) in Zurich; and prevalence of probable FA ranged from 1.9% (0.8-3.5) in Reykjavik to 5.6% (3.6-8.1) in Lodz. In all centers, most food-sensitized subjects had primary (non-cross-reactive) FS. However, FS due to birch pollen related cross-reactivity was also common in Central-Northern Europe. Probable FA to milk and egg occurred frequently throughout Europe; to fish and shrimp mainly in the Mediterranean and Reykjavik. Peach, kiwi, and peanut were prominent sources of plant FA in most countries, along with notably hazelnut, apple, carrot, and celery in Central-Northern Europe and lentils and walnut in the Mediterranean.

CONCLUSIONS

There are large geograhical differences in the prevalence of FS and FA in school-age children across Europe. Both primary and cross-reactive FS and FA occur frequently.

Aortopexy for the treatment of tracheobronchomalacia in 100 children: a 10-year single-centre experience

OBJECTIVES

Our study describes and analyses the results from aortopexy for the treatment of airway malacia in children.

METHODS

Demographic data, characteristics and preoperative, operative and outcome details, including the need for reintervention, were collected for children undergoing aortopexy between 2006 and 2016.

RESULTS

One hundred patients [median age 8.2 months, interquartile range (IQR) 3.3-26.0 months] underwent aortopexy. Sixty-four (64%) patients had tracheomalacia (TM) only, 24 (24%) patients had TM extending into their bronchus (tracheobronchomalacia) and 11 (11%) patients had bronchomalacia. Forty-one (41%) children had gastro-oesophageal reflux disease, of which 17 (41%) children underwent a Nissen fundoplication. Twenty-eight (28%) children underwent a tracheo-oesophageal fistula repair prior to aortopexy (median 5.7 months, IQR 2.9-17.6 months). The median duration of follow-up was 5.3 years (IQR 2.9-7.5 years). Thirty-five (35%) patients were on mechanical ventilatory support before aortopexy. Twenty-seven (77%) patients could be safely weaned from ventilator support during the same admission after aortopexy (median 2 days, IQR 0-3 days). Fourteen patients required reintervention. Overall mortality was 16%. Multivariable analysis revealed preoperative ventilation (P = 0.004) and bronchial involvement (P = 0.004) to be adverse predictors of survival. Only bronchial involvement was a predictor for reintervention (P = 0.012).

CONCLUSIONS

Aortopexy appears to be an effective procedure in the treatment of children with severe airway malacia. Bronchial involvement is associated with adverse outcome, and other procedures could be more suitable. For the treatment of severe airway malacia with isolated airway compression, we currently recommend aortopexy to be considered.

Respiratory muscle training improves respiratory muscle endurance but not exercise tolerance in children with cystic fibrosis

BACKGROUND

Respiratory muscle endurance (RME) training has been shown to increase exercise endurance and lung function in adults with cystic fibrosis (CF). We conducted an interventional study to investigate the effectiveness of RME training on CF-related health outcomes in children.

METHODS

In a crossover trial, 22 children, aged 9-18 years, with CF performed 8 weeks of RME training and standard chest physiotherapy in a randomized sequence separated by a 1 week washout period. All children underwent training sessions using the RME training device before beginning the study. The primary outcomes were RME (in minutes) and exercise endurance (in minutes). Data were analyzed according to the intention-to-treat principle.

RESULTS

Sixteen of 22 children (73%) completed the study. Study dropouts tended to be older with more advanced lung disease. After RME training, respiratory muscle endurance significantly increased by 7.03 ± 8.15 min (mean ± standard deviation, P < 0.001), whereas exercise endurance was unchanged by RME training (0.80 ± 2.58 min, P = 0.169). No significant improvement in secondary outcomes (lung function, CF quality of life, and CF clinical score) were observed. The small sample size and short intervention time have to be acknowledged as limitations of our study.

CONCLUSIONS

RME training led to a significant increase in respiratory muscle endurance in children with CF. However, RME training did not improve exercise endurance or other CF-related health outcomes. Thus, our results do not support the routine use of RME training in the care of children with CF. Future studies in larger populations and with prolonged intervention time may overcome the limitations of our study. Pediatr Pulmonol. 2017;52:331-336. © 2017 Wiley Periodicals, Inc.

Perspective on cystic fibrosis and physical activity: Is there a difference compared to healthy individuals?

OBJECTIVES

The aim of this study was to compare habitual physical activity between cystic fibrosis (CF) patients and healthy controls and to investigate possible predictors for reduced physical activity in CF patients.

METHODS

Sixty-six patients with CF (3-44 years) and 65 healthy controls (3-55 years) were asked to wear an accelerometer (Actigraph GT1M) for 9 days (at least 10 hr/day). Physical activity was classified in five categories from very low to very strenuous.

RESULTS

In general, there was no difference in physical activity between CF patients and healthy controls. However, young school-aged 6-13 years old children with CF spent less time with strenuous and very strenuous activity than healthy controls (adjusted difference in activity -0.43 (-0.69, -0.17)). Patients with very low lung function were significantly less active, but other CF-associated conditions did not affect physical activity.

CONCLUSIONS

While we found similar levels of physical activity measured by accelerometry in patients with CF compared to healthy controls in general, young school-aged children showed less engagement in strenuous activities than their healthy counterparts. As the reduced physical activity in young school children was not likely to be explained by the disease state, strenuous physical activity may be enhanced by advocating exercise and sport. Pediatr Pulmonol. 2016;51:1020-1030. © 2016 Wiley Periodicals, Inc.

Blood plasma lipidome profile of dairy cows during the transition period

BACKGROUND

The transition period of dairy cows, around parturition and the onset of lactation, involves endocrine and metabolic changes to compensate for an increased energy requirement aggravated by reduced feed intake. Transition cows adjust to the resulting negative energy balance with the mobilization of lipids from the adipose tissues yielding increased blood levels of non-esterified fatty acids and ketone bodies like β-hydroxybutyrate.

RESULTS

To study the biochemical adaptations underlying this physiologic adjustment and possible pathologic derangements, we analyzed the blood plasma lipidome of transition cows by ultra-pressure liquid chromatography coupled to high-resolution quadrupole time-of-flight mass spectrometry. The resulting data were processed by principal component analysis, revealing over 60 lipid masses that change in abundance over the test period ranging from two weeks before calving to four weeks postpartum. Further characterization of analytes by tandem mass spectrometry demonstrated that the concentration of triacylglycerides in plasma drops at the day of parturition whereas the plasma level of many phosphatidylcholines and two sphingomyelins increases steadily during early lactation.

CONCLUSION

This newly identified shift in phospholipid composition delivers a potential biomarker to detect aberrant metabolic pathways in transition cows and also provides insights into how to prevent and treat associated disorders like fatty liver disease.

Pulmonary Function Test Abnormalities in Pediatric Inflammatory Bowel Disease

BACKGROUND

Pulmonary involvement in adult patients with inflammatory bowel disease (IBD) seems more common than previously appreciated. Its prevalence and development over time in pediatric IBD patients are largely unknown.

OBJECTIVES

The aim was to study lung function including fraction of exhaled nitric oxide (FeNO) and transfer capacity for carbon monoxide (TLCO) in pediatric IBD patients and to describe the longitudinal development in a subset of patients with lung function abnormalities.

METHODS

Sixty-six measurements were made in 48 IBD patients (30 patients with Crohn's disease and 18 with ulcerative colitis) and 108 matched controls. Patients with abnormal TLCO or elevated residual volume/total lung capacity (RV/TLC) ratios were invited for a follow-up. Statistical comparisons were made by nonparametric tests and ANOVA.

RESULTS

TLCO was decreased in IBD patients [median: 88% predicted (interquartile range, IQR, 22) vs. 99% predicted (IQR 19) in controls]. RV/TLC ratios were mildly elevated in patients with ulcerative colitis [32% (IQR 9) vs. 27% (IQR 8) in controls], and maximum expiratory flows at 50 and 25% of vital capacity were mildly reduced in patients with Crohn's disease. FeNO and disease activity did not correlate with lung function abnormalities. Abnormalities did not consistently persist over a median follow-up period of 34 months.

CONCLUSIONS

This study supports evidence that variable and fluctuating pulmonary involvement also occurs in pediatric IBD patients. Its clinical significance is unclear.

Expression of genes related to anti-inflammatory pathways are modified among farmers' children

Background

The hygiene hypothesis states that children exposed to higher loads of microbes such as farmers’ children suffer less from allergies later in life. Several immunological mechanisms underpinning the hygiene hypothesis have been proposed such as a shift in T helper cell balance, T regulatory cell activity, or immune regulatory mechanisms induced by the innate immunity.

Objective

To investigate whether the proposed immunological mechanisms for the hygiene hypotheses are found in farmers’ children.

Methods

We assessed gene expression levels of 64 essential markers of the innate and adaptive immunity by quantitative real-time PCR in white blood cells in 316 Swiss children of the PARSIFAL study to compare farmers’ to non-farmers’ expressions and to associate them to the prevalence of asthma and rhinoconjunctivitis, total and allergen-specific IgE in serum, and expression of Cε germ-line transcripts.

Results

We found enhanced expression of genes of the innate immunity such as IRAK-4 and RIPK1 and enhanced expression of regulatory molecules such as IL-10, TGF-β, SOCS4, and IRAK-2 in farmers’ children. Furthermore, farmers’ children expressed less of the T_H1 associated cytokine IFN-γ while T_H2 associated transcription factor GATA3 was enhanced. No significant associations between the assessed immunological markers and allergic diseases or sensitization to allergens were observed.

Conclusion

Farmers’ children express multiple increased innate immune response and immune regulatory molecules, which may contribute to the mechanisms of action of the hygiene hypothesis.

Induction of specific immunotherapy with hymenoptera venoms using ultrarush regimen in children: safety and tolerance

Background & Objective. Ultrarush induction for specific venom immunotherapy has been shown to be reliable and efficacious in adults. In this study its safety and tolerance in children was evaluated. Methods. Retrospective analysis of 102 ultrarush desensitizations carried out between 1997 and 2005 in 94 children, aged 4 to 15 years. Diagnosis and selection for immunotherapy were according to recommendations of the European Academy of Allergy and Clinical Immunology. Systemic adverse reactions (SARs) were described using the classification of H. L. Mueller. Results. All patients reached the cumulative dose of 111.1 μg hymenoptera venom within 210 minutes. Six patients (6%) had allergic reactions grade I; 2 patients (2%) grade II and 5 patients (5%) grade III. Three patients (3%) showed unclassified reactions. SARs did not occur in the 15 patients aged 4 to 8 years and they were significantly more frequent in girls (29%) compared with boys (12%) (P = 0.034, multivariant analysis) and in bee venom extract treated patients (20%) compared to those treated with wasp venom extract (8%) (OR 0.33, 95% Cl 0.07-1.25). Conclusion. Initiation of specific immunotherapy by ultrarush regimen is safe and well tolerated in children and should be considered for treating children with allergy to hymenoptera venom.

Gene-environment interaction for childhood asthma and exposure to farming in Central Europe

BACKGROUND

Asthma is a disease in which both genetic and environmental factors play important roles. The farming environment has consistently been associated with protection from childhood asthma and atopy, and interactions have been reported with polymorphisms in innate immunity genes.

OBJECTIVE

To detect gene-environment interactions for asthma and atopy in the farming environment.

METHODS

We performed a genome-wide interaction analysis for asthma and atopy by using 500,000 genotyped single nucleotide polymorphisms (SNPs) and farm-related exposures in 1708 children from 4 rural regions of Central Europe. We also tested selectively for interactions between farm exposures and 7 SNPs that emerged as genome-wide significant in a large meta-analysis of childhood asthma and 5 SNPs that had been reported previously as interacting with farm exposures for asthma or atopy.

RESULTS

Neither the asthma-associated SNPs nor the SNPs previously published for interactions with asthma showed significant interactions. The genome-wide interaction study did not reveal any significant interactions with SNPs within genes in the range of interacting allele frequencies from 30% to 70%, for which our study was well powered. Among rarer SNPs, we identified 15 genes with strong interactions for asthma or atopy in relation to farming, contact with cows and straw, or consumption of raw farm milk.

CONCLUSION

Common genetic polymorphisms are unlikely to moderate the protective influence of the farming environment on childhood asthma and atopy, but rarer variants, particularly of the glutamate receptor, metabotropic 1 gene, may do so. Given the limited statistical power of our study, these findings should be interpreted with caution before being replicated in independent farm populations.

Prenatal animal contact and gene expression of innate immunity receptors at birth are associated with atopic dermatitis

BACKGROUND

Cross-sectional studies have suggested that prenatal farm exposures might protect against allergic disease and increase the expression of receptors of the innate immune system. However, epidemiologic evidence supporting the association with atopic dermatitis remains inconsistent.

OBJECTIVE

To study the association between prenatal farm-related exposures and atopic dermatitis in a prospective study. We further analyzed the association between the expression of innate immune genes at birth and atopic dermatitis.

METHODS

A total of 1063 children who participated in a birth cohort study, Protection against Allergy-Study in Rural Environments, were included in this study. Doctor diagnosis of atopic dermatitis was reported by the parents from 1 to 2 years of age by questionnaire. Gene expression of Toll-like receptors (TLRs) and CD14 was assessed in cord blood leukocytes by quantitative PCR.

RESULTS

Maternal contact with farm animals and cats during pregnancy had a significantly protective effect on atopic dermatitis in the first 2 years of life. The risk of atopic dermatitis was reduced by more than half among children with mothers having contact with 3 or more farm animal species during pregnancy compared with children with mothers without contact (adjusted odds ratio, 0.43; 95% CI, 0.19-0.97). Elevated expression of TLR5 and TLR9 in cord blood was associated with decreased doctor diagnosis of atopic dermatitis. A significant interaction between polymorphism in TLR2 and prenatal cat exposure was observed in atopic dermatitis.

CONCLUSION

Maternal contact with farm animals and cats during pregnancy has a protective effect on the development of atopic dermatitis in early life, which is associated with a lower expression of innate immune receptors at birth.

Early mobilization after flexor tendon repair in children

PURPOSE

Aim of the study was to provide an age-adapted rehabilitation protocol for flexor tendon repairs of children and to evaluate a patient series accordingly.

METHODS

A modified Kessler's technique was used to repair 49 flexor tendon injuries in 39 children. All children had immediate postoperative mobilization according to the protocol that provides specific guidelines for preschoolers, children and teenagers. Range of motion was monitored and the final results were evaluated retrospectively.

RESULTS

All children could be treated successfully according to the protocol with no occurrence of secondary tendon ruptures. Forty finger injuries were evaluated according to the Strickland classification, resulting in a median total active motion of 92.6 % with 29 (72.5 %) excellent results, 8 (20 %) good results, 3 (7.5 %) fair results and no poor result. All 7 thumbs had an excellent result according to the Buck-Gramcko score. There was no significant difference in outcomes between the three age groups.

CONCLUSIONS

The rehabilitation protocol provided in this study allows an age-adapted early mobilization of children's hands after flexor tendon injuries. It respects age-specific limitations in rehabilitation and takes a child's superior healing capacity compared to adults into account. The good results and the very low complication rate observed in the present series suggest that the extra effort of early mobilization may be justified.

Gene expression measurements in the context of epidemiological studies

BACKGROUND

Gene expression measurements became an attractive tool to assess biological responses in epidemiological studies. However, collection of blood samples poses various technical problems. We used gene expression data from two epidemiological studies to evaluate differences between sampling methods, comparability of two methods for measuring RNA levels and stability of RNA samples over time.

METHODS

For the PARSIFAL study, PBLC of 1155 children were collected using EDTA tubes in two countries. In the PASTURE study, tubes containing RNA-stabilizing solutions (PAXgene) Blood RNA Tubes; PreAnalytiX) were used to collect cord blood leucocytes of 982 children in five countries. Real-time PCR (conventional single tube assay and high-throughput low density arrays) was used to quantify expression of various innate immunity genes. In 77 PARSIFAL samples, gene expression was measured repeatedly during prolonged storage.

RESULTS

In PARSIFAL (EDTA tubes) the median RNA yield after extraction significantly differed between the two centres (70 and 34 ng/microl). Collecting blood into an RNA-stabilizing solution markedly reduced differences in RNA yield in PASTURE (range of medians 91-107 ng/microl). The agreement [Spearman rank correlation (r)] between repeated measurements of gene expression decreased with increasing storage time [e.g., for CD14: r (first/second measurement) = 0.35; r (first/third measurement) = 0.03]. RNA levels measured with either the conventional method or low-density arrays were comparable (r > 0.9).

CONCLUSION

Collecting blood samples into tubes containing an RNA-stabilizing solution increases RNA yield and reduces its variability. Long-term storage of samples may lead to RNA degradation, requiring special attention in longitudinal studies.

A polymorphism in CD14 modifies the effect of farm milk consumption on allergic diseases and CD14 gene expression

BACKGROUND

Consumption of farm milk in early life is associated with less asthma and allergies.

OBJECTIVE

We hypothesized that genetic variation in the innate immunity receptor CD14 might modify the association between farm milk consumption and asthma and atopy.

METHODS

Questionnaire data, serum IgE levels, and genotypes for 4 single nucleotide polymorphisms in CD14 were assessed in farmers' and nonfarmers' children from 2 European populations (Allergy and Endotoxin study, n = 576; Prevention of Allergy Risk factors for Sensitization in children related to Farming and Anthroposophic Lifestyle study, n = 1539). In a subsample (n = 222) CD14 gene expression was measured in peripheral blood leukocytes. The effects of farm milk and CD14 genotypes on asthma, allergies, and CD14 expression and their interactions were investigated.

RESULTS

We found a significant interaction between genetic variation in CD14/-1721 and farm milk consumption. Adjusted odds ratios for the association between farm milk and asthma varied between the genotypes: AA, 0.18 (95% CI, 0.07-0.47); AG, 0.47 (95% CI, 0.26-0.86); and GG, 0.98 (95% CI, 0.46-2.08). Similar patterns were observed for symptoms of allergic rhinoconjunctivitis and pollen sensitization. CD14/-1721 also modified the association between farm milk and CD14 gene expression (adjusted geometric means ratios: AA, 1.61 (95% CI, 0.98-2.66); AG, 1.11 (95% CI, 0.71-1.72); and GG, 0.76 (95% CI, 0.39-1.48).

CONCLUSION

The protective effect of farm milk consumption on allergic diseases is stronger in children carrying the A allele in CD14/-1721 than in children homozygous for the G allele. This might be mediated through farm milk-induced upregulated CD14 gene expression.

CLINICAL IMPLICATIONS

Our results support the hypothesis that the inverse association between farm milk consumption and allergic diseases is mediated by CD14-activated innate immune mechanisms.

Inverse association of farm milk consumption with asthma and allergy in rural and suburban populations across Europe

BACKGROUND

Dietary interventions as a means for atopy prevention attract great interest. Some studies in rural environments claimed an inverse association between consumption of farm-produced dairy products and the prevalence of allergic diseases, but current evidence is controversial.

OBJECTIVE

To investigate whether consumption of farm-produced products is associated with a lower prevalence of asthma and allergy when compared with shop-purchased products.

METHODS

Cross sectional multi-centre study (PARSIFAL) including 14,893 children aged 5-13 years from five European countries (2823 from farm families and 4606 attending Steiner Schools as well as 5440 farm reference and 2024 Steiner reference children). A detailed questionnaire including a dietary component was completed and allergen-specific IgE was measured in serum.

RESULTS

Farm milk consumption ever in life showed a statistically significant inverse association with asthma: covariate adjusted odds ratio (aOR) 0.74 [95% confidence interval (CI) 0.61-0.88], rhinoconjunctivitis: aOR 0.56 (0.43-0.73) and sensitization to pollen and the food mix fx5 (cut-off level of >or=3.5 kU/L): aOR 0.67 (0.47-0.96) and aOR 0.42 (0.19-0.92), respectively, and sensitization to horse dander: aOR 0.50 (95% CI 0.28-0.87). The associations were observed in all four subpopulations and independent of farm-related co-exposures. Other farm-produced products were not independently related to any allergy-related health outcome.

CONCLUSION

Our results indicate that consumption of farm milk may offer protection against asthma and allergy. A deepened understanding of the relevant protective components of farm milk and a better insight into the biological mechanisms underlying this association are warranted as a basis for the development of a safe product for prevention.

Not all farming environments protect against the development of asthma and wheeze in children

BACKGROUND

In recent years, studies have shown a protective effect of being raised in a farm environment on the development of hay fever and atopic sensitization. Inconsistent data on the relation of farming to asthma and wheeze have raised some doubt about a true protective effect.

OBJECTIVE

We sought to study the differential effects of farm-associated exposures on specific asthma-related health outcomes.

METHODS

The cross-sectional Prevention of Allergy Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Lifestyle study included 8263 school-age children from rural areas in 5 European countries. Information on farm-related exposures and health outcomes was obtained by using questionnaires. In subsamples allergen-specific IgE and RNA expression of CD14 and Toll-like receptor genes were measured, and dust from children's mattresses was evaluated for microbial components.

RESULTS

Inverse relations with a diagnosis of asthma were found for pig keeping (odds ratio [OR], 0.57; 95% CI, 0.38-0.86), farm milk consumption (OR, 0.77; 95% CI, 0.60-0.99), frequent stay in animal sheds (OR, 0.71; 95% CI, 0.54-0.95), child's involvement in haying (OR, 0.56; 95% CI, 0.38-0.81), and use of silage (OR, 0.55; 95% CI, 0.31-0.98; for nonatopic asthma) and in Germany for agriculture (OR, 0.34; 95% CI, 0.22-0.53). Protective factors were related with higher expression levels of genes of the innate immunity. Potential risk factors for asthma and wheeze were also identified in the farm milieu. Levels of endotoxin and extracellular polysaccharides were related to the health outcomes independently of the farm exposures.

CONCLUSIONS

The protective effect of being raised in a farm environment was ascribed to distinct exposures.

CLINICAL IMPLICATIONS

The development of atopic sensitization and atopic and nonatopic asthma is most likely determined by different environmental factors, possibly reflecting distinct pathomechanisms.

Prenatal farm exposure is related to the expression of receptors of the innate immunity and to atopic sensitization in school-age children

BACKGROUND

There is increasing evidence that environmental exposures determining childhood illnesses operate early in life. Prenatal exposure to a farming environment through the mother might also play an important role.

OBJECTIVE

We sought to investigate the role of maternal exposures to environments rich in microbial compounds for the development of atopic sensitization, asthma, and corresponding alterations in the innate immune system in offspring.

METHODS

In the children of the cross-sectional Prevention of Allergy Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Life Style study, asthma and atopy were assessed by means of standardized questionnaires (n = 8263) and serum IgE measurements (n = 2086). In a subsample (n = 322) gene expression of Toll-like receptors (TLR2 and TLR4) and CD14 was assessed. Maternal exposures were defined through questionnaire information.

RESULTS

Both atopic sensitization (adjusted odds ratio, 0.58; 95% CI, 0.39-0.86) and the gene expression of receptors of innate immunity were strongly determined by maternal exposure to stables during pregnancy, whereas current exposures had much weaker or no effects. A dose-response relation was found between the extent of upregulation of these genes and the number of different farm animal species the mother had encountered in her pregnancy. Each additional farm animal species increased the expression of TLR2, TLR4, and CD14 by a factor of 1.16 (95% CI, 1.07-1.26), 1.12 (95% CI, 1.04-1.2), and 1.10 (95% CI, 1.03-1.23), respectively.

CONCLUSION

Maternal exposure to an environment rich in microbial compounds might protect against the development of atopic sensitization and lead to upregulation of receptors of the innate immune system. The underlying mechanisms potentially operating through the intrauterine milieu or epigenetic inheritance await further elucidation.

CLINICAL IMPLICATIONS

When assessing risk factors of allergies in an infant's medical history, attention must also be paid to environmental exposures affecting the mother.