Dietary prevention of allergic diseases in infants and small children.

Because of scientific fraud four trials have been excluded from the original Cochrane meta-analysis on formulas containing hydrolyzed protein for prevention of allergy and food intolerance in infants. Unlike the conclusions of the revised Cochrane review the export group set up by the Section on Paediatrics, European Academy of Allergology and Clinical Immunology (SP-EAACI) do not find that the exclusion of the four trials demands a change of the previous recommendations regarding primary dietary prevention of allergic diseases. Ideally, recommendations on primary dietary prevention should be based only on the results of randomized and quasi-randomized trials (selection criteria in the Cochrane review). However, regarding breastfeeding randomization is unethical, Therefore, in the development of recommendations on dietary primary prevention, high-quality systematic reviews of high-quality cohort studies should be included in the evidence base. The study type combined with assessment of the methodological quality determines the level of evidence. In view of some methodological concerns in the Cochrane meta-analysis, particularly regarding definitions and diagnostic criteria for outcome measures and inclusion of non peer-reviewed studies/reports, a revision of the Cochrane analysis may seem warranted. Based on analysis of published peer-reviewed observational and interventional studies the results still indicate that breastfeeding is highly recommended for all infants irrespective of atopic heredity. A dietary regimen is effective in the prevention of allergic diseases in high-risk infants, particularly in early infancy regarding food allergy and eczema. The most effective dietary regimen is exclusively breastfeeding for at least 4-6 months or, in absence of breast milk, formulas with documented reduced allergenicity for at least the first 4 months, combined with avoidance of solid food and cow's milk for the first 4 months.

Frequency of detection of picornaviruses and seven other respiratory pathogens in infants.

BACKGROUND: Previous studies in which molecular-based techniques have been used to identify the causative pathogens of respiratory tract infection have investigated hospitalized children only. We report a prospective study designed to determine the frequency and clinical presentation of community-acquired respiratory illness in infancy associated with 8 common respiratory pathogens. METHODS: Eighty-eight infants were monitored through their first winter. With each respiratory illness, infants were examined, and a nasal lavage specimen was collected. Individual reverse transcription-polymerase chain reactions were performed to detect infection with picornaviruses (rhinoviruses and enteroviruses), coronaviruses (serotypes OC43 and 229E), adenoviruses, parainfluenza viruses 1-3, influenza viruses (types A and B), respiratory syncytial virus (RSV), Chlamydia pneumoniae and Mycoplasma pneumoniae. RESULTS: Picornaviruses were the most frequently detected pathogen identified in 46% (56 of 123) of episodes, followed by RSV (27%), parainfluenza viruses (13%) and coronaviruses (9%). Dual pathogen infections were identified in 20% of episodes, predominantly caused by picornaviruses together with either RSV or parainfluenza viruses. RSV infection was significantly associated with a diagnosis of bronchiolitis. No other associations were found between pathogen and clinical diagnosis. Dual infection did not predispose infants to a more severe clinical course. CONCLUSIONS: Picornaviruses are the predominant cause of community-acquired respiratory tract infection in the first year of life. Large prospective community-based studies will be needed to fully evaluate the contribution of picornaviruses, both in isolation and in combination with other respiratory pathogens, to the various clinical syndromes of respiratory infection observed during infancy.

Dietary prevention of allergic diseases in infants and small children. Part III: Critical review of published peer-reviewed observational and interventional studies and final recommendations.

The role of primary prevention of allergic diseases has been a matter of debate for the last 40 years. In order to shed some light on this issue, a group of experts of the Section of Pediatrics EAACI reviewed critically the existing literature on the subject. An analysis of published peer-reviewed observational and interventional studies was performed following the statements of evidence as defined by WHO. The results of the analysis indicate that breastfeeding is highly recommended for all infants irrespective of atopic heredity. A dietary regimen is unequivocally effective in the prevention of allergic diseases in high-risk children. In these patients breastfeeding combined with avoidance of solid food and cow's milk for at least 4-6 months is the most effective preventive regimen. In the absence of breast milk, formulas with documented reduced allergenicity for at least 4-6 months should be used.

Dietary prevention of allergic diseases in infants and small children. Part II. Evaluation of methods in allergy prevention studies and sensitization markers. Definitions and diagnostic criteria of allergic diseases.

The role of primary prevention of allergic disease has been a matter of debate for the last 40 years. In order to shed some light into this issue a group of experts of the Section of Pediatrics EAACI critically reviewed the existing literature on the subject. The design of observational and interventional studies was evaluated with relevance to the important factors influencing outcome of studies on allergy development/prevention. in this analysis the statements of evidence as defined by WHO were applied. Best evidence of recommendations are those fulfilling the criteria for statements category 1 and 2 and grade of recommendations A and B as proposed by WHO. This survey include target group for dietary prevention and methods and diagnostic criteria of atopic dermatitis, asthma and food allergy for prevention studies.

Dietary prevention of allergic diseases in infants and small children. Part I: immunologic background and criteria for hypoallergenicity.

The role of primary prevention of allergic diseases has been a matter of debate for the last 40 years. In order to shed some light into this issue, a group of experts of the Section of Pediatrics EAACI critically reviewed the existing literature on the subject. In this paper, the immunology of the fetus and newborn is reviewed as well as the post-natal development of the immune system. The influence of post-natal environment and breastfeeding on tolerance induction and sensitization are examined. Allergic diseases result from a strong relationship between genetic and environmental factors. Sensitization to food allergens occurs in the first year of life and cow's milk allergy is the first food allergy to appear in the susceptible infants. Hypoallergenicity of food formulas to be used is a critical issue both for treatment of cow's milk-allergic children and for prevention. Methods to document hypoallergenicity are discussed and evaluated in the preclinical and clinical steps.

Type 1 and type 2 cytokine imbalance in acute respiratory syncytial virus bronchiolitis.

We examined the in vivo immune response of infants to natural respiratory syncytial virus (RSV) infection through analysis of cytokine levels in nasal lavage fluid and stimulated peripheral blood mononuclear cells. Eighty-eight babies with at least one parent with atopy and asthma were prospectively studied through their first winter. Twenty-eight infants had an upper respiratory tract infection where RSV was detected, of whom nine developed signs of acute bronchiolitis. Nasal lavage specimens were assayed for interferon-gamma, interleukin (IL)-4, IL-10, and IL-12 and the RSV load determined by quantitative polymerase chain reaction. Messenger RNA (mRNA) was extracted from stimulated peripheral blood mononuclear cells and interferon-gamma, IL-4, IL-12, and IL-18 mRNA levels determined by polymerase chain reaction. Cytokine profiles were analyzed in relation to clinical outcome. The IL-4/interferon-gamma ratio for infants with acute bronchiolitis was elevated in nasal lavage fluid on both Days 1-2 (p = 0.014) and Days 5-7 (p = 0.001) of the illness compared with infants with upper respiratory tract infection alone. Those with acute bronchiolitis demonstrated a higher IL-10/IL-12 ratio (p = 0.0015) on Days 1-2. IL-18 mRNA levels were reduced (p = 0.019) and the IL-4/interferon-gamma ratio elevated (p = 0.01) in stimulated peripheral blood mononuclear cells from infants with acute bronchiolitis. There was no difference in initial RSV load. These data strongly implicate excess type 2 and/or deficient type 1 immune responses in the pathogenesis of RSV bronchiolitis.

Reduced soluble CD14 levels in amniotic fluid and breast milk are associated with the subsequent development of atopy, eczema, or both.

BACKGROUND: Exposure to various microbial products in early life reduces the risk of atopy. Such exposure induces downregulation of T(H)2 allergy-biased responses by means of pattern recognition molecules, such as CD14, an LPS receptor. OBJECTIVE: We sought to determine whether infant and maternal levels of soluble CD14 (sCD14) are associated with the atopic outcomes of infants. METHODS: Levels of sCD14 in plasma, amniotic fluid, and breast milk were measured with a specific ELISA in different cohorts. Expression of toll-like receptors in the fetal gut was examined by using RT-PCR. RESULTS: Soluble CD14 levels increased during fetal development and postnatally, attaining adult levels by around 4 months of age, with an overshoot of adult levels from 6 months of age. There was no difference in plasma sCD14 levels at birth of children with a high compared with those with a low risk of development of atopy. Amniotic fluid sCD14 levels at midgestation (16-17 weeks) were significantly lower when the child was subsequently atopic (P <.05). Soluble CD14 levels in breast milk collected 3 months postpartum were significantly lower in children with eczema at 6 months of age, irrespective of whether they were atopic (P =.003). Transcripts for toll-like receptor 4, which would enable transmembrane signaling for LPS/sCD14 complexes, were expressed within fetal gut and skin. CONCLUSION: Exposure to reduced levels of sCD14 in the fetal and neonatal gastrointestinal tract is associated with the development of atopy, eczema, or both. Thus the exogenous supply of sCD14 might influence immunologic reactivity both locally and systemically in early life and thereby influence disease outcome.