Robert A. Barbee

Distribution of IgE in a community population sample: correlations with age, sex, and allergen skin test reactivity

The distribution of total serum IgE determined by the paper radioimmunosorbent test (PRIST) is examined in a large random stratified community population. Prior to logarithmic conversion the distribution of this immunoglobulin is not normal, with almost 40% of values below 20 IU/ml. A normal distribution occurs following such conversion, with a geometric mean value of 32.1 IU/ml. Both age and sex, in addition to atopic status, relate to IgE level. In both sexes highest levels occur among 6- to 14-year-olds, and males have higher levels than females at any given age. Women over age 75 yr have the lowest levels (geometric mean 9.2 IU/ml). Subjects with positive skin test results have several times the concentration of IgE as their nonatopic counterparts.

Immediate Skin-Test Reactivity in a General Population Sample

To assess the prevalence and distribution of allergic skin-test reactions in a general population sample, allergy prick tests were applied to 3101 subjects older than 2 years of age. Test materials included allergens common to the Tucson environment, and subjects were randomly stratified by age, sex, and socioeconomic status. No difference in the prevalence of measurable reactions was found among male subjects versus female subjects. A definite age relation was apparent, however, with the peak prevalence of reactivity (more than 40%) occurring during the third decade, and falling rapidly past age 50. When present, reactions tended to be multiple, highly reproducible, and more frequent among those in the higher socioeconomic strata. The prick test was judged to be a useful tool for the assessment of atopy.

Longitudinal changes in allergen skin test reactivity in a community population sample

A cohort of 1333 subjects, aged 3 years and older, was followed for a mean of 8.1 years to assess changes in allergen skin test reactivity. The overall prevalence of reactivity to the five antigen mixtures was 39.1% during the initial survey and 50.7% after the follow-up period. The greatest increase in prevalence occurred among children and teenagers (22.2% and 19.5%) with only minimal increases after the age of 65 years (6.0%). No difference in prevalence between male and female subjects was apparent, either initially or at the end of the follow-up period. In-migration to the Tucson area was a major factor in determining changes in reaction prevalence. Among subjects more than 35 years of age, recent in-migrants accounted for most of the increased prevalence. Comparisons of atopy among consistent smoking groups confirmed the previous observation that smokers are less atopic than either nonsmokers or exsmokers, probably because of a self-selection process. In contrast, exsmokers were generally the most atopic, both initially and at the end of the longitudinal observation period. The high overall prevalence of allergen reactivity in this population is believed to be due in large measure to high year-round concentrations of multiple aeroallergens in the Tucson environment.

A longitudinal study of serum IgE in a community cohort: Correlations with age, sex, smoking, and atopic status

A number of factors, including age, sex, smoking habits, and atopic status have been reported in cross-sectional studies to influence levels of serum IgE. We have examined the effects of these variables on serum IgE in a community population cohort of 1109 subjects during a longitudinal study in which two serum samples were obtained 8 years apart from each subject. For the entire cohort, mean serum IgE level changed little during the follow-up period (28.9 versus 26.0 IU/ml). Most of the decreases were observed in children and young adults. Subjects more than the age of 35 years demonstrated no systematic change in serum IgE levels. By the end of follow-up (when there were few subjects still less than 16 years of age), significant relationships of IgE to age could no longer be demonstrated in nonatopic subjects. Also, in the nonatopic subjects of this cohort, there were no significant differences in IgE levels between the sexes. Among atopic subjects, there was a clear tendency for IgE to decrease with age, with atopic women more than 35 years of age demonstrating greater declines in IgE levels during follow-up than men of comparable age. The IgE levels in atopic male subjects were significantly higher than in atopic female subjects after the age of 35 years. Smoking was associated with an elevation in serum IgE. In this cohort, the smoking effect appeared to be limited to male subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory Disorders and Allergy Skin-Test Reactions

This study examines the relations of allergy skin-test reactivity, assessed by prick testing, to a variety of respiratory symptoms, findings, and diagnoses in a general population sample consisting of more than 3000 subjects. The independent and combined relations of skin-test reactivity and cigarette smoking are reported. Prevalences of asthma and allergic rhinitis are closely related to the severity of skin-test reactions; all of the 39 subjects with the largest skin-test reactions observed have had one or both of these conditions. A variety of other respiratory findings, not generally considered allergic in nature, are also related to skin-test reactivity, especially in children and in young to middle-aged adults. In subjects 15 to 54 years of age, an atopic predisposition, as manifested by reactions to allergy skin tests, appears to be associated with an increased susceptibility to the bronchoconstrictor effects of cigarette smoking and to recurrent chest infections. It is suggested that an atopic predisposition relatively early in life may be a risk factor for the later development of chronic obstructive lung diseases.

Allergen skin-test reactivity in a community population sample: correlation with age, histamine skin reactions, and total serum immunoglobulin E

Allergen skin reactivity to 14 common local antigens was studied in a community population sample. Differences in the prevalence of positive reactions were related to both the specific antigen itself and the age of the subjects. For most allergens, peak prevalence occurred in the 20- to 34-yr age group, falling thereafter with increasing age. The frequency distribution of reactions revealed a bimodal curve, peaks occurring among nonreactors and those with eight positive reactions out of the 14 tests that were applied. The major contributor to this age--skin test relationship was the level of total serum IgE that was highest in young people and decreased progressively with age. Histamine skin reactions, which were smallest in younger subjects compared with all three older age groups, also contributed to the age-related prevalence of allergen skin-test reactions.

The relationship of respiratory allergy, skin test reactivity, and serum IgE in a community population sample☆

Abstract The relationship between prick and intradermal skin test reactivity and serum levels of total and specific IgE was evaluated in 311 subjects selected from a general population. Test results were related to the historical allergy status of the subjects. Prick test reactivity to 14 common local allergens correlated with the presence of allergy symptoms. Similarly, mean total serum IgE (PRIST) levels were significantly higher (p

The natural history of asthma

Our understanding of the natural history of asthma is improving through the establishment of a more precise definition of asthma linked with information from large-scale longitudinal studies. Risk factors for the development of childhood asthma including sex, atopic status, genetic and familial factors, respiratory infections, and outdoor and indoor pollution are now more clearly understood. New information on the relation of viral wheezing episodes in infancy to later childhood asthma is evolving. We now know that children who start wheezing early in life and continue to wheeze at age 6 years are more likely to have a maternal history of asthma, elevated serum IgE levels, and normal lung function in the first year of life. However, at age 6 years they have both elevated serum IgE levels and diminished lung function. Approximately 50% of adults who report having had childhood asthma no longer have symptoms. Airway responsiveness in childhood tends to predict airway responsiveness in adulthood and to be greater in asthmatics with persistent symptoms. Studies of the natural history of asthma support the hypothesis that early therapeutic intervention in mild disease may lead to an improved clinical outcome. Adults exposed to specific occupational environments are at additional risk for the development of asthma. As we learn more about the natural history of asthma, we will have a better understanding of the effect of early diagnosis, environmental control, and therapy on the outcome of the disease.

An epidemiologic study of the interrelationships of total serum immunoglobulin E, allergy skin-test reactivity, and eosinophilia

Abstract In a general population sample from Tucson, Arizona, we examined the effects of age, sex, and smoking habits on the interrelationships of total serum IgE, allergy skin-test reactivity, and peripheral blood eosinophilia. Allergy skin-test reactivity showed a direct linear relationship to total serum IgE, but this relationship was differentially affected by age and smoking habits. The frequency of positive skin-test reactivity for a given level of IgE was greater among females than that among males, but a comparison of female and male nonsmokers indicated that this difference was attributable to differences in smoking habits rather than sex. Subjects less than 16 and those over 45 yr of age demonstrated reduced skin-test reactivity for a given level of IgE when compared with subjects 16 to 45 yr of age. Restricting the analysis to nonsmokers diminished (but did not obliterate) this age effect. Those over 45 yr of age (but not those less than 16) were shown to have reduced levels of IgE specific for Bermuda grass as compared with the 16 to 45 yr age group. The skin of subjects less than 16 and those over 65 yr of age was reduced in its capacity to respond to histamine. Thus the reduction in the skin-test reactivity of subjects less than 16 yr of age appears to involve a reduction in their skin reactivity to mediators, whereas for those over 45 it is related to a reduction in IgE specific for common aeroallergens, and for those over 65 it is apparently related to both of these causes. The frequency of peripheral blood eosinophilia was also found to be directly related to total serum IgE. Skin test-negative subjects had the same frequency of eosinophilia as that in skin test-positive subjects at any given level of serum IgE. Males had higher rates of eosinophilia than did females for a given level of IgE, but this difference also became insignificant if the analysis was restricted to nonsmokers. The increase in eosinophilia among smokers as compared with nonsmokers with equivalent serum IgE levels implies that smoking may trigger immunologic reactions associated with eosinophilia.

Nitrogen dioxide-induced pulmonary disease: five new cases and a review of the leterature.

Twenty-three patients exposed to nitrogen dioxide in agriculture or industry were referred to the University of Wisconsin Medical Center. Eighteen experienced a transient upper respiratory tract syndrome; five developed pulmonary edema or bronchiolitis obliterans. This latter group responded to steroid therapy but all demonstrated evidence of persistent pulmonary dysfunction on follow-up studies. Combining our findings with those in the literature we concluded: (1) exposure to NO2 is more common than generally appreciated; (2) case fatality is high--29% for silo-fillers disease; (3) steroids are effective therapy and should be continued for at least eight weeks; (4) although the majority recover without significant sequelae, some individuals may develop persistent functional abnormalities; (5) there is no evidence that long-term exposure to low concentrations of NO2 leads to chronic airway obstruction; and, (6) NO2-induced pulmonary disease could be elminated with appropriate preventive measures.