Biomedical subjects

Robert S Zeiger

Publications and source records attributed to Robert S Zeiger.

32 records · Page 2Linked to original sources

PubMed2005

The role of breast-feeding in the development of allergies and asthma.

Breast-feeding is the preferred method of infant nutrition for numerous reasons. However, its role in the prevention of allergic disease remains controversial. Reasons for this controversy include methodological differences and flaws in the studies performed to date, the immunologic complexity of breast milk itself and, possibly, genetic differences among patients that would affect whether breast-feeding is protective against the development of allergies or is in fact sensitizing. The preponderance of evidence does suggest, however, that there would be much to lose by not recommending breast-feeding. In general, studies reveal that infants fed formulas of intact cow's milk or soy protein compared with breast milk have a higher incidence of atopic dermatitis and wheezing illnesses in early childhood. Consistent with these findings, exclusive breast-feeding should be encouraged for at least 4 to 6 months in infants at both high and low risk of atopy and irrespective of a history of maternal asthma.

Allergens↗

PubMed2005

Relationships among quality of life, severity, and control measures in asthma: an evaluation using factor analysis.

BACKGROUND: Validated psychometric tools measuring quality of life, asthma control, and asthma severity have been developed, but their relationships with each other and with other important patient-centered outcomes have not been rigorously assessed. OBJECTIVE: To use factor analysis to evaluate the relationships of these validated tools with each other and with other patient-centered outcomes. METHODS: Surveys were completed by a random sample of 2854 Health Maintenance Organization members age 18 to 56 years with persistent asthma. Surveys included demographic information; validated tools measuring generic (Short Form-12; SF-12) and asthma-specific (Juniper Mini Asthma Quality of Life Questionnaire; AQLQ) quality of life, asthma control (Asthma Therapy Assessment Questionnaire), and asthma symptom severity (Asthma Outcomes Monitoring System); self-described severity, control, and course over time; and history of acute exacerbations. RESULTS: Principal component analysis suggested a 5-factor model that accounted for approximately 59% of the variability. The most prominent rotated factor reflected asthma symptom frequency (19.4% of variability), was measured by the symptom subscale of the AQLQ, and was the only factor significantly related to the Asthma Therapy Assessment Questionnaire, Asthma Outcomes Monitoring System, or the self-reported assessments of severity, control, or course. Other factors included symptom bother (12.1% of variability), reflected by the environment and emotion AQLQ subscales; activity limitation (13.9% of variability), reflected by the activity AQLQ subscale and the SF-12 physical component scale; mental health (8.3% of variability), reflected by the SF-12 mental component scale; and acute exacerbations (5.0% of variability), not measured by any of the validated scales. CONCLUSION: Distinct components of patient-reported asthma health status can be identified by factor analysis. Distinct constructs of severity versus control cannot be identified by the use of these tools alone.

Adolescent↗

PubMed2004

The Prevention of Early Asthma in Kids study: design, rationale and methods for the Childhood Asthma Research and Education network.

Pediatric asthma remains an important public health concern as its prevalence and cost to the health care system is rising. In order to promote innovative research in asthma therapies, the National Heart, Lung and Blood Institute created the Childhood Asthma Research and Education Network in 1999. As its first study, the steering committee of the Childhood Asthma Research and Education Network designed a randomized clinical trial to determine if persistent asthma could be prevented in children at a high risk to develop the disease. This communication presents the design of its first clinical trial, the Prevention of Asthma in Kids (PEAK) trial and the organization of the Childhood Asthma Research and Education Network that developed and implemented this trial. Studies of the natural history of asthma have shown that, in persistent asthma, the initial asthma-like symptoms and loss of lung function occur predominately during the first years of life. Therefore, in the Prevention of Asthma in Kids study, children 2 and 3 years old with a positive asthma predictive index were randomized to twice daily treatment with fluticasone 88 microg or placebo via metered-dose inhaler and Aerochamber for 2 years. The double blind treatment period was followed by a 1-year observational period. Lung function was measured by spirometry and oscillometry technique at 4-month intervals throughout the study. Bronchodilator reversibility and exhaled nitric oxide (ENO) studies were performed at the end of the treatment and observation periods. The primary outcome measure was the number of asthma-free days. Other secondary outcomes included number of exacerbations, use of asthma medications and lung function. These measures were chosen to reflect the progression of the disease from intermittent wheezing to persistent asthma and measurement of the extent of airflow limitation and airway reactivity.

Administration, Inhalation↗

PubMed2004

Atopic characteristics of children with recurrent wheezing at high risk for the development of childhood asthma.

BACKGROUND: Few studies have characterized the atopic profile of toddler-aged children with recurrent wheezing at high risk of the development of persistent asthma. Objective We sought to determine the atopic profile of toddler-aged children with frequent wheeze at high risk for the development of persistent asthma who either had a parental history of asthma, a personal history of atopic dermatitis, or both. METHODS: Participants enrolled in the Prevention of Early Asthma in Kids study (n = 285) on the basis of a modified Asthma Predictive Index were characterized on the basis of allergy and asthma questionnaire responses and allergy skin puncture test results. RESULTS: The majority of the children (60.7%, n = 148) were sensitized to either food or aeroallergens. Male children were significantly more likely to be sensitized to aeroallergens ( P = .03) and to have a blood eosinophil level of 4% or greater ( P = .03) and a total serum IgE level of greater than 100 IU/mL ( P = .0004). Additionally, eosinophilia and total serum IgE level had the strongest correlation with aeroallergen sensitization. CONCLUSION: The high prevalence of aeroallergen sensitization in this high-risk cohort suggests that aeroallergens might have an important role in the early development of asthma. As such, the Prevention of Early Asthma in Kids cohort appears to be an appropriate cohort in which to test whether early intervention with an inhaled corticosteroid can significantly attenuate, or perhaps even prevent, the allergic march from the initial stages of allergic sensitization to the subsequent development of asthma in toddlers with episodic wheezing.

Age Factors↗

PubMed2004

Variability of symptoms in mild persistent asthma: baseline data from the MIAMI study.

OBJECTIVE: To describe the variability of the asthma phenotype in patients with mild persistent asthma enrolled in the Mild Asthma Montelukast versus Inhaled Corticosteroid (MIAMI) study. METHODS: The variability of asthma rescue-free days, asthma symptoms, albuterol use, medical resource use, and exercise Limitations among patients with documented mild persistent asthma was compared between the month before study enrollment and the last 2 weeks of the run-in period. RESULTS: Patients eligible for randomization (n = 400), aged 15-85 years, exhibited symptoms (mean +/- SD) 3.6 +/- 1.3 days/week, beta-agonist use 3.5 +/- 1.3 days/week, and normal FEV1 (94.0 +/- 9.9% predicted) during the last 2 weeks of the run-in period. In the year before enrollment, medical intervention for asthma flares was common: 38.5% made office visits, 15.8% had oral corticosteroids, and 8.3% required emergency room or hospitalized care. In the month before enrollment, 11.8% experienced daily symptoms, and 28.3% had limitations of normal activity. Patients with daily symptoms in the month before study enrollment, compared with those having less-than-daily symptoms, experienced fewer rescue-free days (P = 0.024) and had more days per week with symptoms (P = 0.008) and requiring albuterol (P = 0.048) during the run-in; FEV1 was similar for both groups (93.1% vs. 94.2% predicted, respectively). CONCLUSION: Patients with mild persistent asthma reported a substantial disease burden in the year before enrollment. The asthma burden experienced by these patients both before and during the run-in period was of sufficient severity to support the recommendation that mild persistent asthma should be managed with daily controller therapy.

Acetates↗

PubMed2004

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.

Breast Feeding↗

PubMed2004

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.

Breast Feeding↗

PubMed2004

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.

Asthma↗

PubMed2003

Relationship of exhaled nitric oxide to clinical and inflammatory markers of persistent asthma in children.

BACKGROUND: Exhaled nitric oxide (eNO) is a noninvasive test that measures airway inflammation. Insufficient information is available concerning correlations between eNO and biologic, physiologic, and clinical characteristics of asthma in children currently not taking controller medications. OBJECTIVE: The aim of this study was to find correlations between eNO and other characteristics of children with mild to moderate asthma currently not taking medications. METHODS: Children aged 6 to 17 years with mild to moderate persistent asthma, taking only albuterol as needed, were characterized during 2 visits 1 week apart before being randomly assigned into a clinical trial. At the screening visit, online measurements of eNO, spirometry before and after bronchodilator, and biomarkers of peripheral blood eosinophils, serum eosinophil cationic protein, total serum IgE, and urinary leukotriene E4 were obtained. During a week characterization period before randomization, symptoms were recorded on a diary and peak expiratory flows were measured twice daily using an electronic device. At the randomization visit, eNO was repeated followed by a methacholine challenge and aeroallergen skin testing. Correlations and rank regression analyses between eNO and clinical characteristics, pulmonary function, and biomarkers were evaluated. RESULTS: eNO was significantly correlated with peripheral blood eosinophils (r =.51, P <.0001), IgE (r =.48, P <.0001), and serum eosinophil cationic protein (r =.31, P =.0003) but not with urinary leukotriene E4 (r =.16, P =.08). A moderate correlation was found between eNO and the number of positive aeroallergen skin tests (r =.45, P <.0001). eNO did not correlate with FEV1% predicted but was weakly correlated with FEV1/forced vital capacity (r = -.19, P =.032), bronchodilator response (r =.20, P =.023), and FEV1 PC20 methacholine (r = -.31, P =.0005). No significant correlations were found between eNO and clinical characteristics or morning or evening peak expiratory flow measurements. The rank regression analysis demonstrated that 5 variables accounted for an R square of.52 (eosinophils [P <.0001], IgE [P =.0023], age [P <.0001], months of inhaled corticosteroid use in the year before study entry [P =.01], and FEV1 PC20 [P =.0061]). CONCLUSIONS: These findings suggest that eNO provides information about the asthmatic state consistent with information from other markers of inflammation. It is a noninvasive technique that could be used in decisional management of children with asthma.

Adolescent↗

PubMed2003

The relationship of frequency of follow-up visits to asthma outcomes in patients with moderate persistent asthma.

BACKGROUND: Although regular follow-up is recommended for patients with asthma, the optimal frequency of such follow-up has not been defined. The purpose of this study was to evaluate the relationship of the interval between routine physician visits to asthma outcomes in patients with moderate persistent asthma. METHODS: The study population was a volunteer sample of subjects aged 18 years or older with moderate persistent asthma requiring at least moderate doses of inhaled corticosteroids who were followed for at least 6 months by one of two allergists in a large staff model HMO. Subjects were randomized to one of three groups: 1) monthly physician visits, 2) semi-annual physician visits, and 3) semiannual physician visits and monthly nurse phone calls. All subjects were advised to call their physician for questions or increased symptoms. The primary outcome variable was total asthma quality of life measured at baseline, 6 months and 12 months. Other outcome variables included specific asthma quality of life domains; spirometry, global asthma rating, satisfaction with treatment rating, and asthma resource and medication utilization during the one year of follow-up. RESULTS: The final cohort included 29 patients per group. There were no significant differences between groups in baseline demographics, smoking history, spirometry, asthma quality of life, global rating, or satisfaction with treatment rating. As per the protocol, patients in the monthly physician visit group made significantly more routine visits during the study than other patients (P<.0001), but there were no other significant differences between groups in any of the other outcome variables at 6 months, 12 months, or during the year of the study. CONCLUSION: Patients with the characteristics of those in this study do not need routine follow-up visits more often than every 6 months. Further studies will be necessary to determine optimal follow-up intervals for patients with other degrees of asthma severity and for those followed in other settings.

Adolescent↗

PubMed2003

Food allergen avoidance in the prevention of food allergy in infants and children.

Food allergy afflicts an increasing number of infants and children and is associated with both clinical and familial burdens. To help lessen this burden, the Nutritional Committees from the American Academy of Pediatrics and jointly the European Society for Pediatric Allergology and Clinical Immunology and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition published recommendations to prevent and treat food allergy. Although there is much in common with these recommendations, differences exist. This review compares, contrasts, and reconciles them, presenting the evidence that has led to their statements.

Allergens↗

PubMed2002

Factors affecting the determination of threshold doses for allergenic foods: how much is too much?

BACKGROUND: Ingestion of small amounts of an offending food can elicit adverse reactions in individuals with IgE-mediated food allergies. The threshold dose for provocation of such reactions is often considered to be zero. However, because of various practical limitations in food production and processing, foods may occasionally contain trace residues of the offending food. Are these very low, residual quantities hazardous to allergic consumers? How much of the offending food is too much? Very little quantitative information exists to allow any risk assessments to be conducted by the food industry. OBJECTIVE: We sought to determine whether the quality and quantity of existing clinical data on threshold doses for commonly allergenic foods were sufficient to allow consensus to be reached on establishment of threshold doses for specific foods. METHODS: In September 1999, 12 clinical allergists and other interested parties were invited to participate in a roundtable conference to share existing data on threshold doses and to discuss clinical approaches that would allow the acquisition of that information. RESULTS: Considerable data were identified in clinical files relating to the threshold doses for peanut, cows' milk, and egg; limited data were available for other foods, such as fish and mustard. CONCLUSIONS: Because these data were often obtained by means of different protocols, the estimation of a threshold dose was very difficult. Development of a standardized protocol for clinical experiments to allow determination of the threshold dose is needed.

Allergens↗

PubMed2002

Current issues with influenza vaccination in egg allergy.

Influenza infection, with its accompanying morbidity and mortality, represents a major public health concern yearly to the elderly and high-risk groups, including asthmatic patients. Active prevention with vaccination consistently falls short of reaching optimal immunization rates in all risk groups. Asthmatic patients and others with concomitant egg allergy might be denied active immunization because of the risk of inducing adverse reactions with a vaccine derived from egg embryo tissue. Evidence supports the relatively safe administration of influenza vaccine to individuals with egg allergy in whom vaccination is indicated when specific protocols are followed under the supervision of experienced physicians. A practical protocol that includes incremental dosing of influenza vaccine is presented to guide clinicians in influenza vaccination in this high-risk group.

Asthma↗

PubMed2002

Association of asthma symptoms with peak particulate air pollution and effect modification by anti-inflammatory medication use.

Maxima of hourly data from outdoor monitors may capture adverse effects of outdoor particulate matter (PM) exposures in asthmatic children better than do 24-hr PM averages, which form the basis of current regulations in the United States. Also, asthmatic children on anti-inflammatory medications may be protected against the proinflammatory effects of air pollutants and aeroallergens. We examined strengths of pollutant associations with asthma symptoms between subgroups of asthmatic children who were on versus not on regularly scheduled anti-inflammatory medications, and tested associations for different particle averaging times. This is a daily panel study of 22 asthmatic children (9-19 years of age) followed March through April 1996 (1,248 person-days). They lived in nonsmoking households in a semirural area of Southern California within the air inversion mixing zone (range, 1,200-2,100 feet) with transported air pollution from urban areas of Southern California. The dependent variable derived from diary ordinal scores is episodes of asthma symptoms that interfered with daily activities. Minimum to 90th-percentile levels of exposures at the outdoor monitoring site were 12-63 microg/m(3) for 1-hr PM < 10 microm in aerodynamic diameter (PM(10)); 8-46 microg/m(3) for 8-hr PM(10); 7-32 microg/m(3) for 24-hr PM(10); 45-88 ppb for 1-hr O(3); 6-26 ppb for 8-hr NO(2); 70-4,714 particles/m(3) for 12-hr daytime fungi; and 12-744 particles/m(3) for 24-hr pollen. Data were analyzed with generalized estimating equations controlling for autocorrelation. There was no confounding by weather, day of week, or linear time trend. Associations were notably stronger in 12 asthmatic children who were not taking anti-inflammatory medications versus 10 subjects who were. Odds ratios (95% confidence intervals) for asthma episodes in relation to lag 0 minimum to 90th-percentile pollutant changes were, respectively, 1-hr maximum PM(10), 1.92 (1.22-3.02) versus 0.96 (0.25-3.69); 8-hr maximum PM(10), 1.68 (0.91-3.09) versus 0.75 (0.18-3.04); 24-hr average PM(10), 1.35 (0.82-2.22) versus 0.80 (0.24-2.69); 1-hr maximum O(3), 1.28 (0.75-2.17) versus 0.76 (0.24-2.44); 8-hr maximum NO(2), 1.91 (1.07-3.39) versus 1.08 (0.30-3.93); 12-hr fungi, 1.89 (1.24-2.89) versus 0.90 (0.35-2.30); 24-hr pollen, 1.90 (0.99-3.67) versus 0.85 (0.18-3.91). Pollutant associations were stronger during respiratory infections in subjects not on anti-inflammatory medications. Although lag 0 1-hr maximum PM(10) showed the strongest association, the most robust associations were for lag 0 and 3-day moving averages (lags 0-2) of 8-hr maximum and 24-hr mean PM(10) in sensitivity analyses testing for thresholds. Most pollutant effects were largely driven by concentrations in the upper quintile. The divergence of exposure-response relationships by anti-inflammatory medication use is consistent with experimental data on inflammatory mechanisms of airborne pollutants and allergens.

Activities of Daily Living↗