Influence of ageing on IgE-mediated reactions in allergic patients

Prevalence and clinical characteristics of allergic rhinitis in the elderly Korean population

PURPOSE

The proportion of elderly people aged ≥ 65 years is increasing worldwide. Although the reported prevalence of sinonasal disease can vary according to the diagnostic methods used, differences in allergic rhinitis prevalence in the elderly according to diagnostic method have not been reported. We thus aimed to evaluate allergic rhinitis prevalence in the elderly according to diagnostic criteria obtained from questionnaires, physician diagnoses, and allergy tests.

METHODS

We compared the allergic rhinitis prevalence in the elderly aged ≥ 65 years with adults aged 19-64 years, using data from the Korean National Health and Nutrition Examination Survey 2008-2012. Total serum IgE and IgE levels specific to allergens of Dermatophagoides farina, cockroach, and dog dander were examined, and factors affecting specific IgE levels were investigated.

RESULTS

Allergic rhinitis prevalence according to the questionnaire responses, physician diagnoses, and allergy test results was 35.02%, 14.89%, and 17.56%, respectively. The prevalence based on all diagnostic methods assessed was significantly lower in the elderly than in the general adult group (p < 0.001). Rhinorrhea incidence was significantly increased in the elderly (p = 0.018). Sensitization to Dermatophagoides farina was significantly decreased in the elderly (p = 0.006) and did not correlate with socioeconomic status and/or general health factors.

CONCLUSIONS

The elderly population has a distinct clinical presentation, including a low prevalence of allergic rhinitis, and an increased incidence of rhinorrhea symptoms, compared with the general adult population. The management of allergic rhinitis in elderly patients may therefore require a different therapeutic approach to improve rhinorrhea rather than nasal obstruction.

In utero exposure to genistein decreased intranasal house dust mite-induced respiratory allergy in middle-aged male B6C3F1 offspring

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental effects are increasing. To understand if in utero GEN exposure modulated postnatal respiratory allergies in the middle age, we conducted a time course study in the B6C3F1 offspring (PND 240-330) using a common household allergen (house dust mites: HDM; 10 μg/mouse for PND 240 and 290, and 50 μg/mouse for PND 330, a middle age in mice) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20 mg/kg body weight). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly dosings of HDM extracts, and they were euthanized at day 3 following the final HDM exposure. In utero exposure to GEN decreased HDM allergen-induced respiratory allergy in male B6C3F1 offspring at PND 330 as reflected by decreases in airway hyperresponsiveness (e.g., Penh value), HDM-specific IgG₁ (a Th2 type Ab) and the activity of eosinophil peroxidase in the lung (an indication of eosinophil recruitment to the lungs). However, in utero exposure to GEN had minimal effects on HDM allergen-induced respiratory allergy in the middle-aged female offspring. Changes in serum total IgE, HDM-specific IgE, and lung histopathology scores in both male and female offspring were not biologically significant. Overall, in utero GEN exposure exerted a protective effect on respiratory allergy in the middle-aged male, but not female, B6C3F1 offspring following later-life HDM exposures.

Allergic children with extremely high total IgE but no allergen identified in the initial screening panel

BACKGROUND

High serum IgE level in atopic children usually implies a highly sensitized condition. However, there is a subgroup of atopic children for whom a specific allergen cannot be identified. In this study, we analyzed follow-up data from these children.

METHODS

From March 2014 to July 2017, we recruited 14 atopic children with serum total IgE level higher than 500 Ku/L, but with no specific allergen identified by repeated MAST tests initially. Follow-up studies of specific IgE were conducted by the OPTIGEN MAST Allergy test and ImmunoCAP assays (Thermo Fisher Scientific/Phadia), while total IgE and specific IgG were measured by ImmunoCAP.

RESULTS

The patients were aged from 2 to 17 y/o. The follow-up MAST tests showed significantly positive results in 10 patients. There were no significant differences in any of the clinical characteristics between the MAST-positive and MAST-negative groups. In the MAST-negative group, five allergen-specific IgE antibodies, including those for cockroach, Euroglyphus maynei, Blomia tropicalis, shrimp, and crab, were strongly predictive of negative ImmunoCAP results, according to ROC (Receiver operating characteristic curve) analysis of the AUC (Area under the Curve of ROC) (0.70-0.95), with significance set at p < 0.05.

CONCLUSION

In two thirds of atopic children with a high serum IgE whose specific allergen had yet to be identified, it was possible to identify the specific MAST allergen(s) after an average follow-up of 33.2 months. For patients who still had negative results in follow-up MAST, mite DP, DF, and DM may be suitable choices for further allergen identification by ImmunoCAP.

Pharmacological Management of Allergic Rhinitis in the Elderly

Recent studies suggest that allergic rhinitis is highly prevalent in the elderly population, but is underdiagnosed and undertreated. This review article briefly introduces allergic rhinitis in the elderly (epidemiology and pathophysiology) and identifies the main goals of treatment in these patients with respect to age-related physiological factors, comorbid conditions and polypharmacy. The primary focus of the article is a narrative review of the literature concerning the different types of treatment options in elderly patients aged 60+ years (pharmacological therapy and allergen-specific immunotherapy). The main management trend for allergic rhinitis in elderly patients is the same as the trend in young patients. Second-generation antihistamines and nasal glucocorticosteroids are also the first-line therapies in seniors. In a few trials, allergen-specific immunotherapy for grass pollen or house dust mites has been shown to be effective and safe in patients aged 60 years or older with allergic rhinitis. In conclusion, undertreatment of allergic rhinitis in the elderly is a reality. Pharmacological treatment is quite similar in both older and younger patients with allergic rhinitis.

The impact of age on serum allergen-specific IgE to inhaled molecular components

BACKGROUND

Respiratory allergy is characterised by an IgE-mediated reaction. The immune system functions, including IgE production, progressively decline over time, such as growing up and ageing. Molecular-based allergy diagnostic defines sensitisation profile. This study aimed to evaluate the impact of age on serum allergen-specific IgE to molecular component levels in a large sample of subjects.

METHODS

Serum IgE to: Phl p1, Bet v1, Ole e1, Cup a1, Par j2, Can f1, Der p2, and Fel d1 were assessed by ISAC method. Sera from 2788 patients, 1230 males (44.1%) and 1558 females (55.9%), median age 23 years (1st and 3rd quartiles: 9.7-49.7 years; age range: 1 month-103 years) were analysed.

RESULTS

The number of positive tests (i.e. sensitisation) tended to increase between birth and school-age till young adulthood and then decreased (p<0.0001) with the exception of Fel d 1 (p=0.14). A similar age-dependent trend was observed considering the levels of each allergen components: the levels of each allergen component, with the exception of Fel d 1, tended to increase till early adulthood and then to decrease reaching the lowest levels in the elderly.

CONCLUSIONS

Allergen-specific IgE production to inhaled molecular components trend to reduce with ageing, but with differences between allergens. This phenomenon should be adequately evaluated managing allergic patients.

The Lancet Weight Determines Wheal Diameter in Response to Skin Prick Testing with Histamine

BACKGROUND

Skin prick test (SPT) is a common test for diagnosing immunoglobulin E-mediated allergies. In clinical routine, technicalities, human errors or patient-related biases, occasionally results in suboptimal diagnosis of sensitization.

OBJECTIVE

Although not previously assessed qualitatively, lancet weight is hypothesized to be important when performing SPT to minimize the frequency of false positives, false negatives, and unwanted discomfort.

METHODS

Accurate weight-controlled SPT was performed on the volar forearms and backs of 20 healthy subjects. Four predetermined lancet weights were applied (25 g, 85 g, 135 g and 265 g) using two positive control histamine solutions (1 mg/mL and 10 mg/mL) and one negative control (saline). A total of 400 SPTs were conducted. The outcome parameters were: wheal size, neurogenic inflammation (measured by superficial blood perfusion), frequency of bleeding, and the lancet provoked pain response.

RESULTS

The mean wheal diameter increased significantly as higher weights were applied to the SPT lancet, e.g. from 3.2 ± 0.28 mm at 25 g to 5.4 ± 1.7 mm at 265 g (p<0.01). Similarly, the frequency of bleeding, the provoked pain, and the neurogenic inflammatory response increased significantly. At 265 g saline evoked two wheal responses (/160 pricks) below 3 mm.

CONCLUSION AND CLINICAL RELEVANCE

The applied weight of the lancet during the SPT-procedure is an important factor. Higher lancet weights precipitate significantly larger wheal reactions with potential diagnostic implications. This warrants additional research of the optimal lancet weight in relation to SPT-guidelines to improve the specificity and sensitivity of the procedure.

In Utero exposure to genistein enhanced intranasal house dust mite allergen-induced respiratory sensitization in young adult B6C3F1 mice

Despite many hypothesized benefits of dietary isoflavone genistein (GEN) deriving from soy-based products, questions surrounding GEN's developmental immunotoxic effects are increasing. To understand how in utero GEN exposure may modulate postnatal respiratory sensitization, we conducted a time course study using a common household allergen (house dust mites: HDM; 10μg/mouse) following intranasal instillation, a physiological route of allergen exposure. GEN was administered to dams by gavage from gestational day 14 to parturition at a physiologically relevant dose (20mg/kg bw). Female and male offspring were sensitized with HDM allergens beginning about one month prior to sacrifice followed by challenges with three weekly doses of HDM extracts, and they were euthanized at day 3 following the final HDM exposure at four different time points (postnatal day (PND) 80, 120, 160, and 200). In utero GEN combined with postnatal HDM exposures (GEN+HDM) increased total IgE production in both young female and male B6C3F1 offspring (e.g., PND 80 in females and PND 120 in males). Increased antigen-specific IgG1, IgG2a and IgG2b levels were also observed at various time points in both female and male offspring. In addition, increases in macrophage number in bronchoalveolar lavage fluid of both female and male GEN+HDM offspring at PND 80 and PND 120, respectively, were observed when compared to the vehicle group. For T cells, an increase over the vehicle in female GEN+HDM offspring was observed at PND 80. Due to similar patterns of increases, it seems likely that GEN+HDM-induced increases in total IgE and macrophages are related. Overall, in utero GEN plus later-life HDM exposures exert increases in total IgE and HDM-specific IgG production as well as macrophage recruitments to the lung in young adult mice.

Rhinitis in older adults

Rhinitis symptoms of rhinorrhea, congestion, sneezing, nasal/ocular pruritis, and postnasal drainage can significantly affect the quality of life for older adults. As the US population ages, it will be increasingly important for health-care providers to effectively diagnose and manage rhinitis. Rhinitis is categorized broadly into allergic rhinitis and non-allergic rhinitis. Environmental changes and avoidance measures are a primary means of intervention. In addition, there are several topical therapies (nasal sprays) that can be effective for symptom control.

The Age Impact on Serum Total and Allergen-Specific IgE

Aging is accompanied by a progressive decline in almost all functions of the immune system. To investigate a possible impact of age on IgE production, this study evaluated total and allergen-specific serum IgE levels in a large cohort of allergic patients. This study included 6,370 allergic patients (2,961 females, 3,409 males; mean age, 21.7 years; age range, 0-96 years). Total and allergen-specific serum IgE levels were measured by immunoenzymatic assay. The analysis of variance showed a significant difference (P<0.0001) in the mean value of total IgE among the different age groups of patients. Moreover, specific IgE levels for all allergens examined differed significantly among the age groups of patients (P<0.0001), with a specific trend pattern for each allergen. Total IgE increased with age, but allergen-specific IgE levels significantly decreased with age, with a trend specific for each allergen tested.

Clinical course of rhinitis and changes in vivo and in vitro of allergic parameters in elderly patients: a long-term follow-up study

Changes in rhinitis symptom severity tend to decrease with aging, but whether the decrease is associated with allergic skin test reactivity, serum total and specific IgE, and nasal eosinophils or determined only by aging is poorly understood. The aim of the study was to analyze sensitivity in vivo and in vitro some 15 years after primary testing, skin prick test (SPT), serum total and specific IgE, ratio sIgE/tIgE, and nasal eosinophils in order to evaluate changes due to age and changes due to the severity of rhinitis symptoms. One hundred and eight rhinitis patients who had been investigated in 1995 were re-interviewed and their current allergy re-assessed after a follow-up of 15 years. All patients were SPT with eight common allergens in the area of Palermo (Italy). Rhinitis symptoms tended, on average, to have become milder at the follow-up. All parameters examined showed a decreasing trend in older age groups over the period between the two investigations. Rhinitis symptoms tend to become milder and the allergic parameters both in vivo and in vitro usually decrease in the long run; however, the changes in rhinitis symptoms appear to be related to changes in the nasal eosinophils, independently of SPT and serum-specific IgE.

Role of allergen sensitization in older adults

There is a common perception among physicians and patients that allergic diseases are not relevant in older adults. There is also recognition that innate and adaptive immune functions decline with aging. It is the function of a variety of immune cells in the form of allergic inflammation that is a hallmark of allergic diseases. In fact, there is a fairly consistent observation that measures of allergic sensitization, such as skin prick testing, specific IgE, or total IgE, decline with age. Nonetheless, the association between allergic sensitization and allergic diseases, particularly asthma and allergic rhinitis, remains robust in the older adult population. Consequently, an appropriate evaluation of allergic sensitivities is warranted and indicated in older asthma and rhinitis patients to provide optimal care for the individual and minimize any resultant morbidity and mortality.

Asthma in the elderly: Current understanding and future research needs--a report of a National Institute on Aging (NIA) workshop

Asthma in the elderly is underdiagnosed and undertreated, and there is a paucity of knowledge on the subject. The National Institute on Aging convened this workshop to identify what is known and what gaps in knowledge remain and suggest research directions needed to improve the understanding and care of asthma in the elderly. Asthma presenting at an advanced age often has similar clinical and physiologic consequences as seen with younger patients, but comorbid illnesses and the psychosocial effects of aging might affect the diagnosis, clinical presentation, and care of asthma in this population. At least 2 phenotypes exist among elderly patients with asthma; those with longstanding asthma have more severe airflow limitation and less complete reversibility than those with late-onset asthma. Many challenges exist in the recognition and treatment of asthma in the elderly. Furthermore, the pathophysiologic mechanisms of asthma in the elderly are likely to be different from those seen in young asthmatic patients, and these differences might influence the clinical course and outcomes of asthma in this population.

The impact of age on prevalence of positive skin prick tests and specific IgE tests

Aging is associated with modifications of the immune system, defined as immunosenescence. This could contribute to a reduced prevalence of allergic disease in the elderly population. In this regard, atopy has rarely been considered in the clinical assessment of the geriatric respiratory patient. This article is a review of the available literature assessing the impact of age on atopy. In the majority of papers, we found a lower prevalence of atopy in the most advanced ages, both in healthy subjects and in individuals affected by allergic respiratory diseases. Unfortunately, no large, longitudinal studies performed in the general population have been conducted to further explore this observation. Although available data seem to favor the decline of allergen sensitization with age, the prevalence of allergic sensitizations in the elderly population with respiratory symptoms is substantial enough to warrant evaluation of the atopic condition. From a clinical perspective, allergic reactions in older adults can have the same or even worse manifestations compared to young people. For this reasons, the evaluation of the atopic condition also in the geriatric patient is recommended. Thus, the role of atopy as it pertains to the diagnosis, therapy (adoption of preventive measure such as removal of environmental allergen or immunotherapy), and prognosis (influence on morbidity and mortality) of chronic respiratory illnesses in the elderly is addressed.

Allergy and asthma in the elderly

Allergies and asthma are diseases that affect individuals of all ages, and their prevalence is comparable in all age groups. As age demographics in the United States and other countries shift to greater proportions and numbers of patients in the "elderly" categories, it is becoming increasingly important for clinicians to become aware of the impact of aging on a variety of diseases. Allergy and asthma are recognized as inflammatory disorders, and there are data demonstrating that age-related changes in immune function can have a significant impact on these disorders.

Effect of ageing on the immune response of dogs to vaccines

Ageing is associated with a decline in functional competence of the immune system, sometimes referred to as immunosenescence. As this increases the susceptibility of dogs to infectious diseases, it is important to determine if the efficacy of vaccines is affected by ageing. Studies to date suggest that the primary response to vaccines may be compromised in old dogs, but recall responses remain intact. Information on the effect of ageing on the duration of protective immunity following vaccination is needed.

Changes in immune function in asthma in the elderly

Asthma is an inflammatory disorder of the airway. The airway inflammation of asthma is typically an allergic inflammation characterized by cells and mediators described as a "Th2" inflammatory response. There is a growing body of evidence describing changes in the function of immune cells upon aging, a phenomenon referred to as "immunosenescence". Several studies utilizing animal models and human subjects with asthma have begun to explore age-related effects on the airway inflammation in asthma. This review explores the existing data on the presence and effects of immunosenescence or age-related changes in immune function in asthma.

Age-related changes in eosinophil function in human subjects

BACKGROUND

Aging results in changes in immune cell function that have been described for T-cells, macrophage, neutrophils, and dendritic cells but not for eosinophils. We sought to define age-related changes in eosinophil function and their potential implications for asthma.

METHODS

We recruited human subjects with asthma in two age groups: a younger group (20 to 40 years), and an older group (55 to 80 years). Lung function, induced sputum, and peripheral blood were obtained from each subject. Eosinophils isolated from the peripheral blood were examined for in vitro functional activities including degranulation, superoxide anion production, adhesion, and chemotaxis.

RESULTS

Eosinophil degranulation in response to interleukin-5 stimulation was significantly decreased in the older group (p = 0.025). Eosinophil production of superoxide anions in response to phorbol myristate acetate was lower in the older group but did not achieve statistical significance (p = 0.097). Eosinophil adhesion, eosinophil chemotaxis, lung function, and the percentage of sputum eosinophils were similar in the two groups.

CONCLUSION

Airway eosinophilia is comparable in younger and older asthma subjects. However, there are age-related changes in peripheral blood eosinophil "effector" functions. Diseases such as asthma, in which eosinophils are thought to play a pathophysiologic role, may exhibit important clinical differences in the elderly due to age-related changes in inflammatory cell function that affect the manifestations of the disease and/or responsiveness to specific classes of medications.

Rhinitis in the elderly

The effects of aging on the nose include structural, hormonal, mucosal, olfactory, and neural changes. As the US population ages and remains in overall better health, we will have more patients with rhinologic problems related to aging. In this manuscript, we review the available evidence on the structural and physiologic changes of the nose caused by aging, and we briefly describe management of common causes of rhinitis in the elderly.

Total and specific serum IgE decreases with age in patients with allergic rhinitis, asthma and insect allergy but not in patients with atopic dermatitis

Concerning allergic diseases, the incidence of allergic symptoms, as well as their severity, seems to decrease with age. The decline of onset of allergic symptoms observed in ageing might result from a decrease of serum total and specific IgE. Atopic disorders are complex diseases that involve interactions among several physiological systems, e.g. skin, lung, mucosae, and the immune system. It was the aim of this study to compare the effects of age on total and specific IgE in patients with atopic dermatitis (AD), allergic rhinitis or asthma, and insect allergy, respectively.

The study population consisted of 559 individuals (male: 229 and female: 330). Total and allergen specific IgE was measured in every individual. From the whole study population, 113 patients suffered from atopic dermatitis (AD), 132 had allergic rhinitis or asthma, and 314 were tested because of insect allergy. Total and specific serum IgE was significantly decreased as a function of age in patients with allergic rhinitis and asthma and with insect allergy. In contrast, no significant decrease of total and specific serum IgE in old individuals with AD was observed. Additionally, in the group of patients with a total IgE < 300 kU/l a reduction of total serum IgE was significantly correlated with age. In contrast, patients with IgE levels > 300 kU/l showed no correlation with age.

Immunosenescence does not affect increased IgE levels in atopic patients with AD and/or high serum IgE levels indicating that in these subgroups of patients the atopic propensity remains into advanced age. One may hypothesize that either onset of allergic sensitization during life or the kind of atopic disease influences the correlation between age and IgE synthesis.

Bimodal skin reactivity to histamine in atopic children in Singapore: influence of specific sensitizations

Histamine skin prick test (SPT) is used as the 'golden standard' for positive control in in vivo immediate type hypersensitivity testing. The skin reactivity to histamine can, however, be modulated by a bevy of extraneous factors. We aimed to define whether histamine skin reactivity in atopic children in Singapore is influenced by age, ethnic origin, gender, environmental exposure or specific sensitization patterns. A retrospective analysis of children, with specific aeroallergen sensitization (as measured by at least one allergen-specific SPT with a wheal size > 3 mm compared with the negative control) from the outpatient speciality clinic of the KK Children's Hospital, during 06/2002-06/2003. A total of 315 patients were included, 235 (75%) were males, 252 (80%) were Chinese, age mean was 7.7 yr (range: 2-15). Patients were referred to the SPT with a diagnosis of one or more of: allergic rhinitis 287 (91%), asthma 112 (36%) or atopic dermatitis 60 (19%). The mean histamine response showed a bimodal distribution, independent of age, ethnic origin, gender or phenotypical expression of allergic disease. Histamine skin reactivity was higher in atopic patients with polysensitization (mean 5.0 mm vs. 2.9 mm in monosensitized patients, p < 0.001), and in patients with mould sensitization (mean 5.1 mm vs. 3.3 mm in patient not sensitized to moulds, p < 0.001). The presence of passive smoking increased the likelihood of a diminished histamine skin response. Histamine skin response data strongly suggested the presence of two heterogeneous subpopulations. Children with polysensitization and mould sensitization were more likely to show a large significant histamine response, whereas children with passive smoke exposure, showed a diminished skin reactivity to histamine.

Cutaneous testing for allergy diagnosis: comparison of methods in common use

Practitioners who treat allergic patients must be familiar with the tests that are available to assist them in establishing the diagnosis. They must also understand the strengths and weaknesses of each of the techniques, devices, and grading systems at their disposal and that there is no criterion standard skin test. This article discusses the various techniques used in skin testing for allergy, their grading systems, and their advantages and disadvantages.

Atopic disorders in ankylosing spondylitis and rheumatoid arthritis

BACKGROUND

The prevalence of atopic disorders in ankylosing spondylitis (AS) is unknown. AS and rheumatoid arthritis (RA) exhibit divergent T helper (Th) cell cytokine patterns.

OBJECTIVE

To test the hypothesis that Th2 polarised atopic disorders may be decreased in Th1 polarised RA but increased in AS, which is characterised by an impaired Th1 cytokine pattern, by assessing the prevalence of atopic disorders in AS and RA.

METHODS

2008 subjects (380 patients with AS, 728 patients with RA, 900 controls) from Berlin, Germany, were considered in this cross sectional study. A questionnaire incorporating questions from the European Community Respiratory Health Service (ECRHS) and the International Study of Asthma and Allergies in Childhood (ISAAC) protocol was mailed to all subjects. Disease severity was assessed by the modified Health Assessment Questionnaire (mHAQ).

RESULTS

1271 (63.3%) people responded to the questionnaire. The prevalence of any atopic disorder was 24.6% (61/248) in patients with AS, 20.7% (111/536) in controls, and 13.1% (64/487) in patients with RA (p=0.0009 for AS v RA; p=0.001 for controls v RA). Hay fever was reported by 40/248 (16.1%) patients with AS, 82/536 (15.3%) controls, and 42/487 (8.6%) patients with RA (p=0.002 for AS v RA; p=0.001 for controls v RA). Atopic dermatitis was reported by 19/248 (7.7%) patients with AS, 26/536 (4.9%) controls, and 14/487 (2.9%) patients with RA (p=0.003 for AS v RA), and asthma by 18/248 (7.3%) patients with AS, 35/536 (6.5%) controls, and 21/487 (4.3%) patients with RA. The differences were related neither to age nor to drugs. Disease severity was less in atopic patients with RA who had the atopic disorder before the onset of RA (median mHAQ 0.75) than in patients in whom RA preceded the atopic disorder (median mHAQ 1.75; p=0.027).

CONCLUSIONS

Atopic disorders are decreased in RA but only slightly and non-significantly increased in AS. This may imply that atopy confers some protection from RA but only little if any susceptibility to AS. It may further indicate that the cytokine deviation towards an impaired Th1 pattern in AS is less strong than the cytokine deviation towards Th1 in RA, a finding which may affect future therapeutic approaches.

Failure of aged rats to accumulate eosinophils in allergic inflammation of the airway

To investigate the effect of aging on the allergic airway response, we examined the bronchoconstrictive responses and cellular inflammatory changes in a rat model of bronchial asthma by evaluating young and old animals. Two different age groups of Brown-Norway rats, actively sensitized by injection of ovalbumin into the foot pads, were used: 7 to 8 weeks old (young group) and 100 to 120 weeks old (aged group). Both the aged and young rats produced on ovalbumin-specific IgE antibody and exhibited an immediate asthmatic response after exposure to ovalbumin, but the degree of specific IgE antibody was significantly higher in young rats. The young group showed a marked increase in the number of eosinophils and neutrophils in bronchoalveolar lavage fluid 2 days after exposure to ovalbumin, whereas no eosinophilia was seen in the aged group. To evaluate the mechanism of the decreased accumulation of eosinophils in aged rats, cells from popliteal lymph nodes from ovalbumin-sensitized rats were incubated with ovalbumin for 48 hours. Although eosinophil chemotactic activity, determined by a modified Boyden chamber method, was present in the supernatant of cultured lymph node cells from young rats, it was absent from those of aged rats. In vivo administration of anti-IL-5 monoclonal antibody revealed that one of the factors of eosinophil chemotactic activity was IL-5. Lymph node cells from aged rats tended to produce greater amounts of interferon-gamma than did those from young animals. Findings indicate that aged rats have a defect in eosinophil accumulation in sites exposed to antigen, probably because of an age-dependent alteration in T cells.

Factors influencing serum immunoglobulin E levels in Greek children

Serum levels of immunoglobulin E (IgE) were determined by enzyme immunoassay in 414 Greek infants and children of both sexes, 1 month to 14 years old. The children were admitted to the "Aghia Sophia" Teaching Hospital for Children (Athens, Greece) for surgical corrections of minor anatomic abnormalities, but they were otherwise healthy. Statistical analysis was performed through multiple regression after logarithmic transformation of the immunoglobulin values. IgE levels increased significantly by about 80% per year up to the age of 5 years, without noticeable impact of age on these levels thereafter. History of allergic disease showed a significant positive association with serum levels of IgE in both younger (less than 5 years) and older children. History of frequent infections was positively associated with IgE levels, although the relation was statistically significant only in the older age group, IgE levels in Greek children appear to be higher than the corresponding levels of children living in northern Europe, but much lower than those of children in Southeast Asia, a fact that may reflect different exposure level during childhood to infections known to influence IgE levels.

Relationships between total serum IgE, atopy, and smoking: a twenty-year follow-up analysis

BACKGROUND

A number of cross-sectional studies have demonstrated that higher levels of IgE are found in subjects who currently smoke cigarettes and/or who are atopic and that IgE levels decline with age.

OBJECTIVE

This report examines the interactions among atopic status, smoking, and IgE with longitudinal data and methods.

METHODS

Subjects were participants in the Tucson Epidemiological Study of Airways Obstructive Disease and were 6 years of age and older. Total serum IgE measures and allergen skin test results were obtained during three surveys spanning a period of up to 20 years.

RESULTS

The results showed no significant gender differences between nonatopic nonsmoking subjects, who were considered the reference group. Nonatopic current smokers had IgE levels similar to those of the reference subjects initially, but IgE levels did not decline with age at the same rate as in the reference subjects, causing significant differences at older ages. There was a significant relationship between number of cigarettes smoked and IgE level.

CONCLUSIONS

Atopy and smoking are both associated with elevated total serum IgE levels. Although the exact mechanism for elevated IgE levels in smokers is not known, the significant dose relationship is suggestive of a causal association.

Host factors and environmental determinants associated with skin test reactivity and eosinophilia in a community-based population study

We examined the relationship of host factors (age, gender) and environmental determinants (smoking status, area of residence) to indicators of allergy (skin test reactivity and eosinophil count) in a random population sample in the Netherlands. Positive skin test reactivity was associated with age (decreasing with increasing age), with male gender (versus female gender), and with urban residence (versus rural residence). Positive skin test reactivity was not associated with smoking. Elevated eosinophil counts were associated with male gender (versus female gender), with urban residence (versus rural residence), and with current smoking (versus never smoking). Elevated eosinophil counts were not clearly associated with age (if adjusted for the age-related effects of skin test reactivity). Additionally, this study specifically demonstrates that skin test reactivity increases with increasing eosinophil count and vice versa, indicating that the two traits are interrelated. Furthermore, this interrelationship was demonstrated to be age-dependent (decreasing with increasing age).

A follow-up study of laboratory animal exposed workers: the influence of atopy for the development of occupational asthma

In a 5-year follow-up study of 88 animal exposed laboratory technicians, the incidence of laboratory animal allergy (LAA), lung function, and the development of allergy test reactivity were investigated. Only two individuals developed test positive LAA rhinitis during the follow-up period. Furthermore, one subject who had previously had LAA rhinitis developed LAA asthma. In the remaining subjects the results of skin prick tests against laboratory animals and environmental allergens, total serum IgE levels, and lung function were unchanged. Atopy defined as parental and childhood allergy, raised total serum IgE levels, and positive skin prick tests against nonanimal environmental allergens and nonlaboratory animals (dog and horse) were risk indicators for development of test positive LAA asthma. The low incidence of LAA during the 5-year follow-up is interpreted as a result of an early LAA development in atopic subjects.

Age-dependency of sensitization to aero-allergens in asthmatics

Skin reactivity (intracutaneous test) to histamine and allergens was studied cross-sectionally in a Dutch asthmatic patient population from childhood to old age (4-75 years). It was found that the histamine skin reactivity rose significantly (p less than 0.05) during childhood, was significantly higher in the 10-15-year age group, and was constant between 20 and 75 years of age. The mean wheal index (histamine ratio) of all allergens was constant during childhood, and decreased after the age of 25 for grass pollen and house-dust mite and after the age of 15 for the other allergens. The prevalence of a positive skin test decreased with age, except for grass pollen. During childhood the indoor allergens, cat dander and house-dust mite, were the most important, while after the age of 15 sensitivity to an outdoor allergen, grass pollen, increased markedly. At all ages house-dust mite was the most important allergen. After the age of 25 the prevalence of every allergen declines. The prevalence of a positive skin test to Cladosporium was unexpectedly high in childhood (10-40%). It can be concluded that the prevalence of a positive skin test declines with age, except for grass pollen. The degree of sensitization in asthmatics peaked in the age groups between 20 and 40 and sensitivity to indoor allergens developed earlier than sensitivity to outdoor allergens.

Isotopic and enzymatic IgE assays in non-allergic subjects

In order to establish normal values in an adult population for serum IgE concentration, sera were obtained from 446 ambulatory Canadian caucasian subjects with negative allergy histories. A standard isotopic procedure, the Phadebas paper radioimmunosorbent test (PRIST), was compared with the new enzymatic counterpart, the Phadezyme PRIST. By the isotopic method, serum IgE concentrations in women and men were comparable from one age group to another with no age-related trend in the seven age groups examined (15-20, 21-30, 31-40, 41-50, 51-60, 61-70, above 70). The median and 95th percentile units (U)/ml respectively were 17.5 and 145 for 224 women and 25.5 and 275 for 222 men. Mean values +/- 1 SD for women were 43 +/- 102 and for men, 58 +/- 137. Levels were significantly higher in men as a group. Sera with IgE concentrations above 100 U and a sampling of additional sera were tested for specific IgE antibodies to 13 common allergens by the radioallergosorbent test (RAST). After exclusion of RAST-positive sera, the mean U/ml values +/- 1 SD were 22 +/- 29 for 204 women and 37 +/- 54 for 196 men. Geometric mean U/ml values for these sera were 14.6 for women and 22.3 for men and the median and 95th percentile U/ml respectively for the women were 15 and 66, for the men, 24 and 135. These 95th percentile values are considered the upper limits of normal in this population. The RAST identification of antibodies to allergens to which sensitization was demonstrated provided a potential explanation for serum IgE concentrations above 100 U/ml in less than 30% of the sera in this population with negative allergy histories. The isotopic method and the counterpart enzymatic method (Phadezyme PRIST) were highly comparable; the correlation coefficient (r) for all the sera was +0.93 (P less than 0.001). IgE levels were significantly higher in male smokers than non-smokers by both methods but these differences were not significant in women.

An epidemiological study on total and specific IgE levels in Japanese schoolchildren

Total serum IgE, and specific serum IgE against mites, Ascaris and Japanese cedar pollen were surveyed in 251 schoolchildren by a radioimmunoassay method. These children, aged from 10 to 13 years and living in a rural Japanese town, were selected according to one-third random population sample. A high concentration of total serum IgE (700 u/ml or more) was found in thirty-one children (12 X 3%). The sex ratio of these children, boys to girls, was 2 X 1:1. The cross-sectional and 6-year follow-up study of total IgE levels showed that they decreased with advancing age. Total IgE levels were significantly related to each of three specific IgE species investigated in this study. The levels of these three specific IgE's were also significantly related to each other. Schoolchildren with high specific IgE levels against mites have had significantly more asthmatic histories compared to children with low specific IgE levels. Such a relationship was not observed for total IgE levels and another two specific IgE species.

Skin reactivity, basophil degranulation and IgE levels in ageing

Skin tests with histamine, the histamine-liberator, codeine, and various allergens as well as blood basophil degranulation by anti-IgE or anti-IgG4 and total serum IgE levels have been studied in two female populations of different ages (average 23.1 and 73.9 years). All thirty-one patients selected for this study were clinically non-allergic. We observed a trend towards reduced skin reactions to histamine and codeine in the higher age-group; on the other hand, we could not find any decrease of basophil degranulation as a sign of basophil impairment with age. Likewise no difference in total serum IgE levels have been noticed. No correlation between skin tests and basophil degranulation was observed; yet patients with isolated, positive skin tests to house dust and/or Candida albicans showed a statistically significant reduced blood basophil degranulation by anti-IgE or anti-IgG4.

Reproducibility of prick skin tests to five allergens

Thirty-five patients had prick skin tests to the common allergens Candida albicans. Aspergillus fumigatus, grass pollen, horse dander and Dermatophagoides pteronyssinus performed on a regular basis from Autumn 1973 to Autumn 1975. Specific IgE to the same allergens (except C. albicans) was determined at the time of skin testing for the first five seasons. It was found that the position on the volar aspect of the forearm on which the test was performed did not affect the reaction. There was a significant variation in the percentage of patients with positive skin tests to A. fumigatus, grass pollen and horse dander with the latter showing as significant decrease with time. There was evidence of variation in weal size for all but C. albicans, and for grass pollen, horse dander and D. pteronyssinus there were reduction in weal size with time. Significant differences were found for results of Log specific IgE for grass pollen and D. pteronyssinus over the study, but there was no trend. A good correlation between weal size and Log specific IgE for grass pollens and D. pteronyssinus was observed. For the four allergens, the coefficient of concordance between IgE levels within patients for the five seasons was highly significant.

Aging and serum immunoglobulin E levels, immediate skin tests, RAST

The changes of the serum IgE levels, specific immediate skin-test responses, and RAST measurements with age were evaluated. A total of 331 unrelated individuals were studied, consisting of 166 subjects with ragweed allergic rhinitis and/or asthma, 67 with idiopathic (intrinsic) asthma, and 98 who appeared in good health with no clinical evidence of atopic diseases. All subjects were evaluated by history and physical examination, intradermal skin testing to the common aeroallergens, measurements of IgE antibody to common aeroallergens with the RAST, and serum IgE levels. Results demonstrated a significant decrease in serum IgE levels with aging in atopic individuals. This decline was exponential in character. In addition, a tendency for RAST and immediate type skin-test responses for selected antigens and histamine to decrease with age was observed.

Clinical features and diagnosis of adult atopic keratoconjunctivitis and the effect of treatment with sodium cromoglycate

This study describes 17 cases of atopic keratoconjunctivitis in adults. In 8 cases the clinical appearances were nonspecific and sufficiently different from vernal keratoconjunctivitis to make diagnosis difficult. These atypical cases often showed a fine papillary conjunctival reaction on the upper tarsus, subconjunctival scarring, and in 1 case severe symblepharon. Corneal features included corneal microcysts, peripheral vascularisation, and various patterns of punctate epithelial keratitis. It was therefore important to establish the atopic status of the patient. A personal or family history of other atopic disease was elicited in every case, and the diagnosis was confirmed by the detection of raised serum IgE level. Uncontrolled clinical assessment suggested that 10 out of 15 patients experienced improvement in symptoms with the use of 2% sodium cromoglycate eyedrops 4 times a day. A subsequent double-masked cross-over trial comparing the same treatment with a matched placebo preparation indicated that 6 out of 9 patients preferred sodium cromoglycate while 1 preferred the placebo. Two patients noted no difference. Cases showing nonspecific or atypical clinical features responded to treatment just as frequently as did cases of typical vernal keratoconjunctivitis.

A genetic-epidemiologic study of human immune responsiveness to allergens in an industrial population: I. Epidemiology of reported allergy and skin-test positivity

Four hundred six subjects, comprising a 10% random sample of all employees, and a sample of "self-reported" allergic employees of a light industrial plant participated in an epidemiologic study of allergy. Puncture skin testing with a wide variety of crude allergens revealed a significantly higher prevalence of IgE-mediated sensitivity in males than females (29% males and 7% females in a random group; 60% males and 30% females in a self-reported allergic group); however, reported prevalence rates for "allergy" and different allergic symptoms were generally not different between males and females. Interestingly, reported asthma was greater in skin-test-positive subjects than in skin-test-negative subjects. We also noted a decrease in skin-test positivity with increasing age in self-reported allergic subjects. This was significant in the case of several crude allergens but not in the case of positivity to at least one allergen. We also found evidence that people born in and who have been resident in "Zone I) (MD, PA, Del, NJ, or DC) for most of their lives exhibit a greater prevalence of skin-test positivity than people who were born in and have lived for much of their lives in the northeastern United States (east of the Mississippi River and to the north of South Carolina) other than in Zone I.

Circulating IgE levels in the over-seventies

In a normal population aged over 70 years the geometric mean IgE value of 30.6 u/ml was not significantly different from that obtained previously in a similar epidemiological survey of a population aged 20-44 years. However, in the older population we have noted a significant sex difference-38.6 u/ml for males against 27.2 u/ml for females-which was only apparent in the atopic subjects of the younger population. There have been some other reports that IgE levels decrease with age, and possible reasons for these differences with our own results are discussed.

Total serum IgE levels in normals and patients with chronic non-specific lung diseases

Total serum IgE was measured, using a sensitive sandwich method, in a healthy control population, in healthy persons with a familial history of chronic non-specific lung disease and in patients with chronic non-specific lung disease (CNSLD). In the control population a median total serum IgE of 39 I.U./ml was found. Total serum IgE levels were significantly lower in women that in men. Healthy persons with a familial history of CNSLD had significantly increased total IgE levels compared with the control population. The IgE level was even higher in the group of patients with CNSLD. The presence of specific IgE antibodies and/or an early onset of the symptoms of CNSLD was accompanied by higher total serum IgE levels compared with the IgE values in the other CNSLD patients. But the total IgE levels were increased in all subgroups of CNSLD patients. A significant decrease of the IgE level with age was observed in CNSLD patients.