The jury is still out on whether supplementation with active prebiotics favorably affects atopic conditions, in particular, atopic dermatitis (AD) and food allergies, in children and adults. This question is becoming increasingly relevant as more and more research is showing that our gut microbiota differs significantly from what is considered to be the primitive state.
Noting that more cases of atopy are associated with children who have little or no familial risk, Grüber et al in this issue investigate the effects of immunoactive, pre-biotic oligosaccharides (OS) added to formula on weaned infants with low atopic risk. The authors created a cow’s milk formula with OS that was very similar to breast milk. Three groups were followed: a group of infants receiving pre-biotic formula (PG), a group receiving formula with no added OS (CG), and an exclusively breastfed group (BG).
The authors report that the incidence of AD in PG infants at the first birthday was reduced 44% as compared to CG infants. This rate was much closer to that of the breastfed group. Severity as measured by TARC levels did not differ between the three groups at the first birthday. Grüber et al. also report that milk and egg specific IgE was not affected, implying that pre-biotic supplementation did not alter sensitization.
Finally, Grüber et al. comment that it would be an important public health issue to know if this effect is persistent. They suggest that it does and could result in reduced respiratory allergy in later life.
We asked Dr. Grüber about the implications of this study:
JACI: Given your results on serum levels of TARC in infants that remained free of AD at their first birthday, please comment about the usefulness of TARC as a biomarker of severity in atopic dermatitis.
Dr. Christoph Grüber: TARC (Thymus- and activation-regulated chemokine) is a Th2-type chemotactic messenger which is upregulated during eczema exacerbation in the blood and which recruits inflammatory cells to the eczematous skin. TARC has been found useful as a biomarker for moderate to severe inflamed skin. Most affected infants in our study had mild eczema. TARC may discriminate non-afflicted and mildly afflicted cases less well.
Do you have any questions for the authors, or comments about this study? We want to hear from you. Please feel free to post your own questions or comments. All questions and comments will be forwarded to the authors for a response.
Friday, October 1, 2010
Review of asthma care in the elderly
This month’s issue includes a clinical review of asthma diagnosis and management in geriatric patients by Charles Reed, MD. Dr. Reed discusses the NAEPP Expert Panel Report 3 (2007) guidelines for diagnosing and managing asthma in the context of the different presentation of late-in-life asthma.
The author points out that clinicians have additional considerations trying to diagnose asthma in geriatric patients. These confounders include decrease in lung function that results from structural compromise associated with aging, comorbid lung disease such as COPD and bronchiectasis, and increased IgE levels that are not allergen specific. Structural changes associated with aging negatively affect pulmonary function testing and often manifest as irreversibility with bronchodilators and increased residual volume.
NAEPP asthma management guidelines can be complicated by a number of characteristics associated with the elderly asthma patients. Drug therapy may be less effective in light of structural changes to the lungs, thus bronchodilators may not be fully effective. Short-acting bronchodilators have the risk of increasing cardiac symptoms and should be avoided, especially in patients with heart disease. Corticosteroid therapy may be effective, but comes with significant side effects such as osteoporosis and hyperglycemia, which are of particular concern in the elderly asthma patient. Furthermore, Dr Reed points out that elderly patients often have difficulty using inhalers effectively, and their inhalation technique needs to be checked at every visit. It may be necessary to switch to old-fashioned pressure nebulizers or oral medications.
Careful assessment of the home environment also remains an important part of management. Dr. Reed emphasizes that, even though elderly patients may not have IgE antibody to aeroallergens, mites, molds and bacteria can cause airway inflammation through innate immune pathways. He notes, “In many elderly asthmatic patients' records, information about the environment is the major omission” (unpublished correspondence). Additionally, anti-fungal medications should be considered if sputum cultures are positive for fungi.
In summary, Dr. Reed revisits the importance of following the guidelines by assessment and control of environmental triggers, effective use of inhaled corticosteroids and oral medications, close evaluation of drug side-effects, and management of comorbid lung disease.
Do you have any questions for Dr. Reed, or comments about this study? We want to hear from you. Please feel free to post your own questions or comments. All questions and comments will be forwarded to the authors for a response.
The author points out that clinicians have additional considerations trying to diagnose asthma in geriatric patients. These confounders include decrease in lung function that results from structural compromise associated with aging, comorbid lung disease such as COPD and bronchiectasis, and increased IgE levels that are not allergen specific. Structural changes associated with aging negatively affect pulmonary function testing and often manifest as irreversibility with bronchodilators and increased residual volume.
NAEPP asthma management guidelines can be complicated by a number of characteristics associated with the elderly asthma patients. Drug therapy may be less effective in light of structural changes to the lungs, thus bronchodilators may not be fully effective. Short-acting bronchodilators have the risk of increasing cardiac symptoms and should be avoided, especially in patients with heart disease. Corticosteroid therapy may be effective, but comes with significant side effects such as osteoporosis and hyperglycemia, which are of particular concern in the elderly asthma patient. Furthermore, Dr Reed points out that elderly patients often have difficulty using inhalers effectively, and their inhalation technique needs to be checked at every visit. It may be necessary to switch to old-fashioned pressure nebulizers or oral medications.
Careful assessment of the home environment also remains an important part of management. Dr. Reed emphasizes that, even though elderly patients may not have IgE antibody to aeroallergens, mites, molds and bacteria can cause airway inflammation through innate immune pathways. He notes, “In many elderly asthmatic patients' records, information about the environment is the major omission” (unpublished correspondence). Additionally, anti-fungal medications should be considered if sputum cultures are positive for fungi.
In summary, Dr. Reed revisits the importance of following the guidelines by assessment and control of environmental triggers, effective use of inhaled corticosteroids and oral medications, close evaluation of drug side-effects, and management of comorbid lung disease.
Do you have any questions for Dr. Reed, or comments about this study? We want to hear from you. Please feel free to post your own questions or comments. All questions and comments will be forwarded to the authors for a response.
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