The epidemiology and genetics of atopic allergy

Respiratory symptoms of rural Fijian and Indian children in Fiji

BACKGROUND

Significant ethnic differences exist in the respiratory morbidity of children in the Fiji Islands. Indian children have higher national hospital admission rates for asthma whereas Fijian children have higher admission rates for pneumonia. In Suva City the prevalence of wheeze is similar in Fijian and Indian children, productive cough is more common in Fijians, and bronchial hyperresponsiveness is more common in Indians. This study was undertaken to see whether ethnic differences in national hospital admission rates are reflected in the prevalence of respiratory symptoms in rural children.

METHODS

A respiratory symptoms questionnaire in three languages with known repeatability was returned by 487 (98.2%) of 496 class 4 primary school children with a mean age of 9.3 years living in Nausori District, an agrarian region with a climate similar to Suva City.

RESULTS

The prevalence of one or more episodes of wheezing in the last 12 months was similar in Fijians (19.8%) and Indians (19.4%). However, 8.9% of Indian children had experienced four or more episodes of wheeze in the last 12 months compared with only 2.9% of Fijian children. Productive cough on most mornings occurred more frequently in Fijians (35.8%) than Indians (23.9%), but this difference was not significant after controlling for the presence of a smoker in the home.

CONCLUSIONS

This study provides the first evidence that frequent wheeze (four or more episodes in the last 12 months) is more prevalent in Indian than Fijian children. The higher prevalence of productive cough in Fijian children may be related to exposure to smoking in the home.

Asthma, allergy and atopy in Asian immigrants in Melbourne

OBJECTIVES

To compare the prevalence of asthma, hay fever and atopy in Asian immigrants in Melbourne with that in Australian-born non-Asians and Australian-born Asians, and to investigate the association of these conditions with atopic status, length of stay in Australia and IgE levels in Asian immigrants.

DESIGN

We performed a cross-sectional study by telephone interviews, using standard questionnaire items on respiratory and allergic symptoms. A random sample of 636 recent Asian immigrants of ethnic Chinese origin, 109 Australian-born Asians and 424 Australian-born non-Asians were selected from the 1991 Melbourne Telephone Directory, using a presumptive surname list. Skin tests to determine atopic status were performed on 269 Asian immigrants and 167 of these also had serum levels of total and specific IgE estimated.

RESULTS

In the under 20 years age group the prevalence of wheeze or asthma ever was higher in Australian-born non-Asians and Australian-born Asians than in Asian immigrants (P < 0.001), and the prevalence of hay fever was higher in Asian immigrants and Australian-born Asians than in Australian-born non-Asians. In those older than 20 years, hay fever was almost twice as common in Asian immigrants as in Australian-born non-Asians (P < 0.001 for 20-40 years age group; P < 0.01 for > 40 years). The prevalence of hay fever and, to a lesser degree, asthma in Asian immigrants increased significantly with length of stay in Australia, independent of age at arrival, sex and atopic status (trend test: P < 0.001 for hay fever; P = 0.05 for asthma). Atopy was more common in Asian immigrants and Australian-born Asians than in Australian-born non-Asians (P < 0.001) and was very strongly associated with both hay fever and asthma, irrespective of length of stay. Pollen and mite sensitivities were more common in Asian subjects (twice as common for Asian-born and 1.5 times for Australian-born) than non-Asian subjects (P < 0.01). Among Asian immigrants, elevated total IgE level (> 100 IU/mL) was strongly associated with a history of hay fever (P < 0.01) and wheeze or asthma ever (P < 0.05), atopy (P < 0.001) and the presence of specific IgE antibodies to grass pollen, dust mite, cockroach and Ascaris antigens (P < 0.05 for all).

CONCLUSION

We found substantial differences in the prevalence of asthma, hay fever and atopy between Asian immigrants, Australian-born Asians and non-Asians. The prevalence of hay fever and asthma in Asian immigrants was strongly associated with length of stay in Australia, suggesting that environmental factors are important in the pathogenesis of these diseases.

Linkage between severe atopy and chromosome 11q13 in Japanese families

Atopy, characterised by allergic asthma and rhinitis, is due to increased IgE responses to common aeroallergens. An Oxford group has described maternal inheritance of atopy, where there is significant linkage between IgE responsiveness and a VNTR marker D11S97 and a CA microsatellite within a candidate gene, the high affinity IgE receptor beta subunit (Fc epsilon RI beta), on chromosome 11q. Attempts at independent replication have produced conflicting results. We therefore recruited 270 atopic asthmatic probands in a Japanese community population for genetic linkage analysis. Four families, each with more than 15 meioses and a clear phenotype for atopy, were selected for genetic analysis. Atopy was defined as presence of all of raised total IgE, positive RAST and skin tests to three or more aeroallergens; non-atopy, as absence of all these criteria. Linkage analysis showed a maximum two-point lod score of 9.35 for D11S97 and Fc epsilon RI beta under the assumption of unequal rates of maternal and paternal recombination. Two families showed close genetic linkage with Fc epsilon RI beta with a pattern of maternal inheritance. These results from a Japanese population provide further evidence for genetic linkage between severe atopy and chromosome 11q13 and the likelihood of genomic imprinting at the locus.

Linkage analysis of IL4 and other chromosome 5q31.1 markers and total serum immunoglobulin E concentrations

Sib-pair analysis of 170 individuals from 11 Amish families revealed evidence for linkage of five markers in chromosome 5q31.1 with a gene controlling total serum immunoglobulin E (IgE) concentration. No linkage was found between these markers and specific IgE antibody concentrations. Analysis of total IgE within a subset of 128 IgE antibody-negative sib pairs confirmed evidence for linkage to 5q31.1, especially to the interleukin-4 gene (IL4). A combination of segregation and maximum likelihood analyses provided further evidence for this linkage. These analyses suggest that IL4 or a nearby gene in 5q31.1 regulates IgE production in a nonantigen-specific (noncognate) fashion.

HLA-DR and HLA-DP genotypes and immunoglobulin E responses to common major allergens

In order to test for human histocompatibility leucocyte antigens (HLA) class II restriction of IgE responses, 431 subjects from 83 families were genotyped at the HLA-DR and HLA-DP loci and serotyped for IgE responses to six major allergens from common aero-allergen sources. A possible excess of HLA-DR1 was found in subjects who were responsive to Fel d I compared with those who were not (Odds Ratio (OR) = 2, P = 0.002), and a possible excess of HLA-DR4 was found in subjects responsive to Alt a I (OR = 1.9, P = 0.006). Increased sharing of HLA-DR/DP haplotypes was seen in sibling pairs responding to both allergens. Der p I, Der p II, Phl p V and Can f I were not associated with any definite excess of HLA-DR alleles. No significant correlations were seen with HLA-DP genotype and reactivity to any of the allergens. The results suggest class II HLA restriction is insufficient to account for individual differences in reactivity to common allergens.

Hospital admission rates for asthma and pneumonia in Fijian and Indian children

To confirm the clinical impression that Melanesian Fijian and Fiji Indian children differ in their profiles of respiratory morbidity, national hospital admission statistics for respiratory diseases in children aged 5-14 years were examined for 4 years between 1985 and 1989. The mean annual admission rate for asthma was three-fold higher in Indians (1.68/1000) than Fijians (0.56/1000); rate ratio (Indian:Fijian) = 3.00, 95% confidence interval 2.54-3.55. Conversely, the mean annual admission rate for pneumonia was three-fold higher in Fijians (1.70/1000) than Indians (0.50/1000); rate ratio (Fijian:Indian) = 3.39 (2.85-4.03). Admission rates for influenza, tuberculosis and bronchiectasis were also higher in Fijian children. Fijian and Indian children differ in hospital admission rates for respiratory diseases, possibly due to differences in incidence, prevalence or severity.

Allergen skin test reactivity in an unselected Danish population. The Glostrup Allergy Study, Denmark

The aim of this study was to assess the distribution of allergen skin test reactivity in an unselected Danish population. A total of 793 subjects, aged 15-69 years, were invited, and 599 (75.5%) attended. The skin prick test was performed with standardized allergen extracts of high potency. Skin reactivity occurred in 28.4% of the subjects. The frequency of skin reactivity to the specific allergens ranged from 1.5% (Cladosporium) to 12.5% (Dermatophagoides pteronyssinus), and the frequencies of skin reactivity to the allergen groups (pollen, animal dander, house-dust mites, and molds) were 17.6%, 8.7%, 14.0%, and 3.2%, respectively. Young women appeared to reflect the average skin reactivity. When compared with young women, skin reactivity to animal dander was more probable in young men (odds ratio (OR) value = 2.6; 95% confidence interval (CI) of odds ratio value = 1.1-6.1). Current smokers were less likely than nonsmokers to be skin-reactive to pollen (OR = 0.4; 95% CI = 0.3-0.7). In conclusion, allergen skin test reactivity was common, and was related to sex, age, smoking history, and probably genetic predisposition.

Interfering factors to sensitivity and specificity of bronchial reactivity in children

Bronchial reactivity to carbachol, estimated by the PD65, the provocation dose of inhaled carbachol inducing a 65% increase of baseline respiratory resistance, was measured in 355 asthmatic children (age 8.7 +/- 2.6 years) and 149 healthy children (age 11.8 +/- 2.3 years). The frequency distribution of PD65 showed apart from 2 minima at 480 micrograms and 960 micrograms 2 significant peaks at 240 micrograms (p = 0.003) and 1200 micrograms (p = 0.01) to carbachol, reflecting a hyperreactive class (PD65 < 480 micrograms), an intermediate class (481 micrograms < PD65 < 960 micrograms) and a normo-reactive class (PD65 > 961 micrograms). The intermediate class is characterised by a considerable overlap between "health" and "disease". However, taking into account the degree of air pollution in which healthy children are living (best related factor to specificity) and the type of initial lung function disorder in asthmatic children, (the MEF50 to be the best related factor for specificity), weighed specificity and sensitivity improved from 64 to 88%. Evaluating bronchial responsiveness in children, such interfering factors should be strongly considered.

Familial occurrence of atopic disease: genetic versus environmental factors

Cumulative life prevalence of atopic disease (any of reported symptoms of asthma/wheezy bronchitis, allergic rhinitis, eczema and urticaria) was studied by means of a questionnaire in 19814 (7-, 10- and 14-year-old) Swedish school children and their parents. Maternal history was found to be twice as common as paternal history. The children of affected mothers contracted atopic disease in the same proportion as the children of affected fathers yielding twice as many affected children with affected mothers than with affected fathers. The strongest parental influence on childhood disease was seen for multiple symptoms and for congruent symptoms with both parents. The number of children with both parents affected was 1.6 times larger than expected. A possible dose-response effect in polygenic inheritance is discussed as well as assumed impact of environmental factors with a tendency to familial clustering.

Lower respiratory tract symptoms in Queensland schoolchildren: risk factors for wheeze, cough and diminished ventilatory function

BACKGROUND

The occurrence of respiratory symptoms and abnormal lung function in children is known to be influenced by genetic and many environmental factors. The association between specific respiratory symptoms in children of school age and their parents has been examined.

METHODS

Respiratory symptoms and ventilatory function were recorded for 4549 schoolchildren in Queensland, Australia.

RESULTS

The cumulative prevalence of wheezing was 23.1% of 8 year olds and 20.8% of 12 year olds, and the prevalence of wheezing within the previous 12 months was 13.9% and 10.5% respectively. A parental history of asthma or wheeze and hayfever was associated with wheeze in the child, but did not affect either the age of onset or frequency of episodes. A history of frequent cough in children who had never wheezed was associated with a parental history of frequent bronchitis, but less strongly with parental wheeze. These familial aggregations were not mediated by common exposure to cigarette smoke. Both a history of parental wheeze and maternal cigarette use were associated with a decrease in FEF25-75 in the child and these effects were additive.

CONCLUSIONS

The association of specific symptoms (wheeze and cough without wheeze) in parent and offspring is interpreted as evidence for different mechanisms of familial transmission, which may be genetic.

Sensitization to four common inhalant allergens within 302 nuclear families

The coincidence of allergic sensitization was investigated in 302 school-aged children and their parents. Specific sensitization to four common inhalant allergens (grass and birch pollens, cat dander, Dermatophagoides pteronyssinus) was ascertained by means of skin-prick tests (SPT) carried out on the complete family unit at the beginning of a 22-month follow-up period. The same test procedure was then repeated on the children twice at 11-month intervals to provide cumulative prevalences of sensitization. A clinical history of atopy in the children (hay fever or asthma; n = 47), which was derived from an interview, is associated with sensitization (positive SPT in 89%). For three allergens (grass and birch pollens, cat dander) sensitization occurs significantly more frequently in the children of mothers who are sensitized to the same allergen (odds-ratios (ORs), 2.5-4.1). Additionally, in three of the four explanatory models related to a single antigen, maternal sensitization to one of the complementary allergens is of importance (ORs, 2.7-3.7). In contrast to this finding, none of the paternal sensitizations has statistical significance. Based on a reaction to at least one of the four allergens, the child's relative risk to be sensitized is increased in case of maternal (OR, 2.88; P = 0.001) but not of paternal (OR, 1.06; P = 0.83) sensitization. In conclusion, our data indicate that the maternal status is more predictive than that of the father with regard to the child's risk of sensitization.

Allergic rhinitis. Helping patients lead an unrestricted life

Allergic rhinitis is a common, chronic disorder that responds well to treatment. Evaluation should begin with thorough history taking and be followed by a comprehensive treatment plan that includes avoidance measures, combination medical therapy, and allergen immunotherapy, when appropriate. The management objective should be to alleviate symptoms so that the patient can lead a normal, unrestricted life.

Heterogeneity of atopy. I. Clinical and immunologic characteristics of patients allergic to cypress pollen

The heterogeneity of pollen-allergic persons is well known but poorly characterized. Cypress is one of the major pollen-producing plants of the Mediterranean area. A study was undertaken to characterize the symptoms presented by patients allergic to cypress pollen and the heterogeneity of the IgE immune response between patients allergic only to cypress pollen and those who are polysensitized. Eighty-nine patients allergic to cypress pollen were studied, 26 being allergic only to cypress pollen. The IgE response was assessed by skin prick tests and the titration of serum total IgE and cypress-specific IgE by RAST. Clinical reactivity was assessed by symptom scores during the cypress pollen season and skin tests. Pollen counts were obtained. The clinical reactivity was similar in both patient groups. Rhinitis was present in all patients, conjunctivitis in 73.7-88.5%, and asthma in only 7.4-19.2%. The age of onset of symptoms caused by cypress pollen allergy was significantly greater in patients allergic to cypress pollen only. Total serum IgE was within the normal range in the cypress pollen group and significantly lower than in the polysensitized groups. Cypress pollen RAST was higher in the polysensitized group. We concluded that conjunctivitis is particularly common in cypress pollen allergy. Patients allergic only to cypress pollen may be unique in their way of expressing serum total IgE levels.

Factors confounding genetic linkage between atopy and chromosome 11q

The results of testing for linkage between atopy and the chromosome 11 marker D11S97 is shown for all the 723 subjects genotyped by us up to January 1992. Lod score estimations were confounded by the high population prevalence of atopy, maternal inheritance of atopy at the 11q locus, genetic heterogeneity, and excess of atopy in families not ascertained through a single proband. Affected sib-pair analysis shows evidence for linkage which is not dependent on the definition of atopy or model specification. We suggest that presentation of sib-pair data will be suitable for meta-analysis of the different studies of genetic linkage and atopy.

Genetic 'risk' for atopy is associated with delayed postnatal maturation of T-cell competence

Recent in vitro studies suggest that IgE production in adults is co-ordinately regulated by negative signals from gamma IFN-producing CD4+ T-helper-1 (TH-1) and positive signals from IL-4 producing (TH-2) T-cells. Additionally, seroepidemiological evidence has pinpointed infancy as the period of maximum lifetime risk for T-cell sensitization to ubiquitous environmental antigens. The present study sought to elucidate the relationship between these observations, by examination of CD4+ T-cell function in normal children and those genetically at 'high risk' for atopy, spanning the age range (up to 4 years) in which IgE responses to environmental allergens is typically manifest. Immunocompetent T-cell precursor frequencies (determined by cloning at limiting dilution) were markedly reduced in 'high risk' children relative to normals (0.53 +/- 0.29 vs 0.26 +/- 0.19; P = 0.0025). Consistent with reports from other laboratories employing bulk T-cell culture techniques, the gamma IFN producing capacity of CD4+ T-cell clones from both groups of children were markedly reduced relative to adults, and was lowest in the high risk group (P < 0.02). IL-4 production by CD4+ T-cell clones from the normal children was within the adult range, but again was significantly lower in the high risk group (P < 0.00005). This indicates that initial immune responses to environmental allergens in early childhood occur against a background of maturational 'deficiency' in CD4+ T-cell function, and suggests the possibility that variations in the rate of postnatal maturation of T-cell competence may be a contributing factor in the development of differing patterns of immunological responsiveness to environmental allergens.

Gastrointestinal food hypersensitivity: basic mechanisms of pathophysiology

Gastrointestinal symptoms occur in a large number of patients with food allergies. Immediate hypersensitivity mechanisms may give rise to the nausea, vomiting, abdominal pain, and diarrhea experienced by these patients. However, there are limited human data about the pathophysiological basis for these symptoms. Most of the available information comes from a variety of animal models. This article reviews the literature using models of intestinal food hypersensitivity, as well as human studies, that have contributed to our understanding of the pathophysiological mechanisms in gastrointestinal food hypersensitivity.

Maternal inheritance of atopic IgE responsiveness on chromosome 11q

Atopy is a common familial state underlying allergic asthma and rhinitis. Lately, we have assigned a gene for atopy to chromosome 11q by linkage to the marker D11S97. Since previous studies have suggested that the risk of atopy is higher for children of atopic mothers than for those of atopic fathers, we sought differences between maternal and paternal patterns of transmission at the 11q13 locus among pairs of siblings in families affected by atopy. When we defined atopy as the presence of a positive skinprick test (greater than or equal to 2 mm) to any of a panel of common allergens, a higher than normal concentration of total serum IgE, or a positive radioallergosorbent test for a specific IgE, we found that 125 (62%) of the sibling-pairs affected by atopy shared the maternal 11q13 allele and 78 (38%) did not. This distribution differs significantly from the expected 50/50 distribution (p = 0.001). Of paternally derived alleles, 83 (46%) were shared and 96 (54%) were not (not significantly different from 50/50). The result was similar whatever definition of atopy was used and with other genetic markers on 11q. These findings show that transmission of atopy at the chromosome 11q locus is detectable only through the maternal line. The pattern of inheritance is consistent either with paternal genomic imprinting or with maternal modification of developing immune responses.

Genetic risk for asthma, allergic rhinitis, and atopic dermatitis

In order to explore the genetic risk of a child with a family history of allergies developing asthma, allergic rhinitis, or atopic dermatitis, questionnaires filled in by 6665 families were analysed. The data were collected in a population based cross sectional survey of 9-11 year old schoolchildren living in Munich and southern Bavaria. The relation between asthma, allergic rhinitis, and atopic dermatitis and the number of allergic first degree relatives, and the type of allergic disease was examined. Analyses were done separately for families with single or multiple allergic diseases. In families with one allergic parent the risk of the child developing asthma was increased by asthma in a parent, with an odds ratio (OR) of 2.6 (95% confidence interval 1.7 to 4.0) but not by parental allergic rhinitis with OR 1.0 (0.7 to 1.5) or atopic dermatitis, OR 1.0 (0.6 to 1.6). For allergic rhinitis the highest risk with OR 3.6 (2.9 to 4.6) was observed with allergic rhinitis of one parent, apparently lower for asthma of one parent, OR 2.5 (1.6 to 4.0) or atopic dermatitis, OR 1.7 (1.1 to 2.5). Children with parental atopic dermatitis had a high risk for atopic dermatitis, OR 3.4 (2.6 to 4.4), compared with children with parental asthma, OR 1.5 (1.0 to 2.2), or parental allergic rhinitis, OR 1.4 (1.1 to 1.8). Risk factors in families with combined allergies of two relatives (parents and siblings) were analysed separately for the different combinations. These results support the hypothesis that asthma, allergic rhinitis, and atopic dermatitis are multifactorial diseases brought about by various familial and environmental influences.

House dust mite sensitivity: interaction of genetics and allergen dosage

Pairwise analysis of siblings from 21 families showed that house dust mite (HDM) sensitive children were exposed to higher concentrations of Der p I allergen in their mattress (P = 0.005) and bedding (P = 0.04), but not bedroom floor (P = 0.33), than their atopic sibling who was not sensitive to HDM antigens. There was no difference in the exposure to HDM numbers/100 mg of dust in the mattress (P = 0.61) or bedroom floors (P = 0.09). In contrast, pairwise analysis of siblings from 15 families showed that HDM sensitive children were not exposed to significantly different concentrations of Der p I in the mattress (P = 0.96), bedding (P = 0.11) or bedroom floor (P = 0.70) nor HDM numbers/100 mg of dust in the mattress (P = 0.12) and bedroom floor (P = 0.98) than their non-atopic siblings. These findings were identical when absolute allergen load was compared in these pairs. Genetic linkage studies in these families suggest the tendency to atopic IgE responses is conferred by a putative atopy locus on chromosome 11q. These results together suggest that differences in allergen levels in beds, among siblings with a comparable genetic tendency to atopy, play a significant role in determining the development of HDM allergy.

MHC associations of autoantibodies against recombinant Ro and La proteins in systemic lupus erythematosus. Results of a multicenter study. SLE Study Group

Antibodies against recombinant 52 kD-Ro, recombinant 60 kD-Ro and recombinant La protein were determined by ELISA in over 300 central European patients with systemic lupus erythematosus (SLE). A strong association with HLA-DR3 was found for antibodies against 52 kD-Ro and La, but not for recombinant 60 kD-Ro antibodies in the absence of antibodies against 52 kD-Ro or La. Ro/La negative SLE patients still showed an increased frequency of HLA-DR3 as compared to healthy controls. These results indicated that the preferential formation of Ro and La antibodies was not due to an unspecific stimulatory effect of HLA-DR3 but that the antibody response to certain defined proteins (52 kD-Ro and La) was influenced by MHC genes in SLE. Furthermore, the association of SLE with HLA-DR3 was independent of the effects of DR3 on the formation of 52 kD-Ro and La antibodies.

Differences in clinical and immunologic reactivity of patients allergic to grass pollens and to multiple-pollen species. II. Efficacy of a double-blind, placebo-controlled, specific immunotherapy with standardized extracts

The IgE response of patients only allergic to grass pollens differs from response of patients allergic to multiple-pollen species. The IgE immunoblots to orchard-grass pollens confirmed that polysensitized patients had more proteins revealed than patients only allergic to grass pollens. To determine if both groups of patients present a different response toward specific immunotherapy (IT), a double-blind, placebo-controlled study was performed in 70 patients. Patients receiving the active treatment had a rush IT with either a standardized orchard grass-pollen extract or with a standardized mixed-pollen extract prepared, depending on the sensitivity of the patients. The maintenance dose was defined as that dose effective in grass-pollen IT in previous experiments. The same equipotent maintenance dose was administered for all pollen species. Symptom-medication scores during the pollen season and nasal challenge with orchard grass-pollen grains demonstrated that grass pollen-allergic patients had a significantly improved efficacy by comparison to placebo treatment, whereas polysensitized patients had a nonsignificant improvement. Serum grass-pollen IgG was significantly increased after IT in both treated groups. This study demonstrate that the response toward specific IT differs in patients only allergic to grass pollens by comparison to polysensitized patients.

Relative risks of bronchial hyper-responsiveness associated with skin-prick test responses to common antigens in young adults

We studied 143 young subjects by skin-prick testing to common allergens and by the measurement of non-specific bronchial responsiveness (NSBR). A logistic regression model showed a prevalence odds ratio (POR) for bronchial hyper-responsiveness (PD20 less than 10 mumol methacholine) in house dust positive subjects of 4.10 (95% CI 1.77-9.51, P less than 0.001), and in mould positive subjects 5.72 (95% CI 2.06-15.9, P less than 0.001): the PORs for epithelia (2.05, P = 0.12) and grasses (1.78, P = 0.19) were not significant. If bronchial reactivity was assessed as measurable (PD20 less than 102 mumol methacholine) or not, the POR for house-dust-positive subjects was 4.83 (95% CI 2.23-10.5, P less than 0.001), for moulds was 10.5 (95% CI 2.33-47.5, P less than 0.001), for epithelia was 4.79 (95% CI 1.91-12.0, P less than 0.001), and for grasses was 2.21 (95% CI 1.11-4.4, P = 0.022). The results show the risk of bronchial hyper-responsiveness is greater in subjects sensitive to house dust and mould than in those reactive to grasses, and suggests that the presence or absence of increased NSBR in atopic individuals may depend on the antigens to which they become sensitized.

Effects of maternal diet during late pregnancy and lactation on the development of IgE and egg- and milk-specific IgE and IgG antibodies in infants

The IgE levels and food-allergen-specific IgE- and IgG-antibodies (Ab) to ovalbumin (OA), ovomucoid (OVO) and beta-lactoglobulin (BLG) were determined up to 18 months of age in 163 infants born to women who were atopic. A high (HIGH group) or a low (REDUCED group) intake of hen's egg and cow's milk by the mother during the third trimester gave no significant differences in the concentrations of IgE or in IgE-Ab (OVO, BLG) and IgG-Ab (OA, OVO, BLG). Similarly, a prolongation of the abstention diet to the early lactation period did not influence the immune response. The IgG-Ab levels to all three food allergens decreased significantly (P less than 0.001) in both study groups between birth and 2 months of age, but then increased significantly (P less than 0.001) between 6 and 18 months of age. The presence in serum of IgE-Ab to OVO (greater than or equal to 0.15 PRU/ml) was associated with significantly higher IgG-Ab levels to OVO at 6 months (P less than 0.001) and at 18 months (P less than 0.05). Infants with positive skin-prick tests (SPT) to OA and OVO showed higher IgG-Ab levels at 6 and 18 months of age than did infants with negative SPT reactions to the two egg allergens. This indicates a relation between the IgE- and IgG-Ab response and it also suggests that some individuals are 'high responders' to both types of immunoglobulin isotypes while others are 'low responders'.

Relationship of total serum IgE levels in cord and 9-month sera of infants

To characterize IgE levels at birth and changes in those levels during the first year of life and to identify factors that might influence IgE levels in infancy, we measured IgE levels in 1074 umbilical cord sera and in 697 sera obtained at 9 months of age in a healthy population of infants enrolled at birth into the Children's Respiratory Study in Tucson, Arizona, U.S.A. Serum IgE levels at birth and 9 months were log normally distributed with geometric means of 0.09 and 3.87 IU/ml, respectively. Cord serum IgE levels were unaffected by maternal smoking. Levels varied according to month of birth with a nadir in September. Cord and 9-month serum IgE levels were higher in boys than in girls, Hispanics compared with Anglos, and infants who developed eczema compared with those who did not, but the mean increases in log IgE from birth to 9 months were not significantly affected by these factors. A significant correlation between IgE levels at cord and 9 months was observed (r = 0.44; P less than 0.0001). Also, mean log IgE levels at 9 months in infants grouped according to cord serum IgE levels maintained the same rank order of mean values as the cord groups. These data indicate that 9-month IgE levels are influenced by cord serum IgE levels and that the main influence of gender, ethnicity and susceptibility to eczema on IgE levels occurs before birth.

A multigene deletion in the immunoglobulin heavy chain region in a highly atopic individual

Highly atopic individuals, with marked allergy, have extremely elevated total plasma IgE levels. To determine if atopy could be associated with structural alterations involving the IGHE gene of the immunoglobulin heavy chain constant region, the genomic DNA from five atopic individuals was examined. We describe here the identification of a deletion of approximately 120kb, including the IGHA1, IGHGP, IGHG2, AGHG4, and IGHE genes of the IGH constant region, in one atopic patient. This deletion arose de novo from a maternally derived chromosome. The deletion, although apparently not the primary cause of the atopic phenotype of this patient, could be indirectly responsible for the phenotype by exposing aberrant immunoglobulin-regulating elements within the paternally derived IGH constant region.

Exposure to house-dust mite allergen (Der p I) and the development of asthma in childhood. A prospective study

BACKGROUND AND METHODS

Children with asthma commonly have positive skin tests for inhaled allergens, and in the United Kingdom the majority of older children with asthma are sensitized to the house-dust mite. In a cohort of British children at risk for allergic disease because of family history, we investigated prospectively from 1978 to 1989 the relation between exposure to the house-dust mite allergen (Der p I) and the development of sensitization and asthma.

RESULTS

Of the 67 children studied in 1989, 35 were atopic (positive skin tests), and 32 were nonatopic. Of the 17 with active asthma, 16 were atopic (P less than 0.005), all of whom were sensitized to the house-dust mite, as judged by positive skin tests and levels of specific IgE antibodies (P less than 0.001). For house-dust samples collected from the homes of 59 of the children in 1979 and from 65 homes in 1989, the geometric means for the highest Der p I exposure were, respectively, 16.1 and 16.8 micrograms per gram of sieved dust. There was a trend toward an increasing degree of sensitization at the age of 11 with greater exposure at the age of 1 (P = 0.062). All but one of the children with asthma at the age of 11 had been exposed at 1 year of age to more than 10 micrograms of Der p I per gram of dust; for this exposure, the relative risk of asthma was 4.8 (P = 0.05). The age at which the first episode of wheezing occurred was inversely related to the level of exposure at the age of 1 for all children (P = 0.015), but especially for the atopic children (r = -0.66, P = 0.001).

CONCLUSIONS

In addition to genetic factors, exposure in early childhood to house-dust mite allergens is an important determinant of the subsequent development of asthma.

Association between left-handedness and allergy: a reappraisal

There are conflicting reports in the literature about the possible association between left-handedness and immune disorders, including autoimmune diseases as well as allergies. In this study we compared the distribution of right- and left-handers, assessed with the Edinburgh Handedness Inventory, in a group of patients consulting an allergy clinic and a control population with a similar sex and age distribution. There was no overall association between left-handedness and allergies, although we found a tendency towards left-handedness in patients whose allergic symptoms started before puberty, suggesting that left-handers may have an increased predisposition to allergic disease that manifests itself during early life.

Association of class I, II, and III MHC gene products with systemic lupus erythematosus. Results of a Central European multicenter study

Class I, II, and III MHC gene products were examined in 248 Central European SLE patients. The previously reported association with HLA-A1, -B8 and -DR3, and C4AQ0 alleles was confirmed. The frequency of HLA-DR2 was also slightly elevated in SLE patients, while no increase in C4BQ0 alleles was observed. Additional findings were a significantly increased frequency of HLA-B13 and a significant decrease of HLA-B44.

Recovery from milk allergy in early childhood: antibody studies

We assessed the relationships of clinical symptoms and serum antibody levels during follow-up of 47 patients, aged 3 to 66 months, who were shown by formal milk challenge to have cow milk allergy. Three groups of patients were identified. Group 1 patients (n = 15) were sensitized to IgE and responded rapidly to small volumes of milk with urticaria, an exacerbation of eczema, wheeze, or vomiting. In the second group (n = 24), symptoms of milk enteropathy (vomiting and diarrhea) developed between 1 and 20 hours after milk ingestion. In the group 3 patients (n = 8), coughing, diarrhea, eczematoid rashes, or a combination of these developed more than 20 hours after normal volumes of milk were given. Serum levels of IgG, IgA, IgM, and IgE and of milk-specific anti-cow milk antibodies of these isotypes were measured initially and then at a median follow-up time of 16 months (range 6 to 39 months). In this investigation, changes in these immunologic measures during the study period were related to whether or not clinical tolerance to cow milk was achieved. At follow-up, six patients from group 1, ten from group 2, and two from group 3 were milk tolerant. No consistent change in any of the immunologic measurements was associated with remission of the disease. These findings raise the question of whether acquisition of clinical tolerance to cow milk in cow milk allergy can be attributed solely to immunologic events.

The load of genetic and partially genetic diseases in man. II. Some selected common multifactorial diseases: estimates of population prevalence and of detriment in terms of years of lost and impaired life

This paper presents epidemiological data on the prevalence of 26 common (i.e., having a lifetime prevalence of more than 1 per 10(4) individuals in the population) multifactorial diseases in Hungary and estimates of detriment associated with them. The detriment is expressed using 3 indicators, namely years of lost life (LL), potentially impaired life (PIL) and actually impaired life (AIL). The total prevalence of these diseases in Hungary has been estimated to be about 6500 per 10(4) individuals in the population. This estimate is in agreement with published data for other parts of the world. On the basis of clinical severity, these diseases have been split into 3 groups, namely (1) very severe (schizophrenia, multiple sclerosis, epilepsy, acute myocardial infarction and related conditions, and systemic lupus erythematosus); (2) moderately severe and/or episodal or seasonal (15 entities including Graves' disease, diabetes mellitus, gout, affective psychoses, essential hypertension, peptic ulcers, asthma, etc.); and (3) less severe than those in the first 2 groups (varicose veins, allergic rhinitis, atopic dermatitis, Scheuermann disease and adolescent idiopathic scoliosis). The essential clinical and genetic aspects of these diseases are briefly discussed. With the exception of epilepsy, none of the diseases included in our list causes mortality between ages 0 and 19. However, they are among the leading causes of death between ages 20 and 69 and thereafter. A sizeable proportion of those with essential hypertension, diabetes mellitus, rheumatoid arthritis, etc. survive to 70 years and beyond, as do those with gout, glaucoma, allergic rhinitis, psoriasis, etc. Overall, about 16% of all deaths that occur in Hungary every year (all age groups) can be attributed to these diseases. The mean number of years of PIL covers a wide range (about 20-40, 12-70 and 40-60 for groups 1, 2 and 3, respectively), the overall mean being about 24 years. However, the nature and degree of impairment and the impact on the life quality of those afflicted differ for the different diseases. Likewise, the mean number of years of AIL (for which the interval between the mean age at premature retirement and mean age at death was used as a rough index) also spans a wide range from 16 to 45, and the overall mean is about 20 years. At the population level, the diseases considered in this paper cause about 2700 years of LL, 96,000 years of PIL and about 5800 years of AIL per 10(4) individuals in the population. Relative to Mendelian diseases as a whole, these multifactorial diseases are associated with much greater detriment (LL: 1.4 X; PIL: 30 X and AIL: 3.9 X).

An epidemiological study of atopy in children

A sample of 930 children, between 9 years and 15 years old from six Italian towns, were studied. Their family history of allergy, personal allergy and medical history, current allergy symptoms, exposure to environmental allergens, feeding as infants, and their parents' occupations were recorded. They were skin-prick tested (SPT) with a range of common allergens. A subject was defined as atopic if at least one SPT caused a weal greater than 3 mm diameter. The association between the recorded information and atopy was investigated by logistic multiple regression. Atopy was positively associated with: high density housing; medium or high exposure to environmental allergens; a history of rhinitis, asthma or atopic eczema; male gender; and a history of breastfeeding. It was independent of infectious diseases, vaccinations and operations, social class and family history. Thus, there was no evidence of a genetic factor in atopy, other than sex.

Immunoglobulin genes, HLA-B8/DR3, and immune responsiveness to primary immunogen and mitogens in normal subjects

The genetic regulation of immune responsiveness by genes from two independent, highly polymorphic genetic systems, namely immunoglobulin allotypes and human leukocyte antigens (HLA), was studied in 35 healthy Caucasian volunteers. The in vivo IgG class antibody response to the primary test immunogen alpha-helix pomatia hemocyanin (HPH) was increased in subjects with the Gm1,17;..;21 haplotype compared to that of the non-Gm1,17;..;21 group. The IgM-class response tended to be higher in the former group. Levels of in vivo IgA-class-specific anti-HPH antibodies tended to be higher in the group of individuals positive for HLA-B8/DR3 than in the non-B8/DR3 group. This difference was statistically significant only in the absence of the Gm1,17;..;21 haplotype. The in vitro lymphocyte proliferative response on mitogenic stimulation with phytohemagglutinin (1 micrograms/ml) and pokeweed mitogen (10 micrograms/ml) also appeared to be associated with both systems. The presence of the Gm1,17;..;21 haplotype was associated with decreased lymphocyte reactivity, whereas the B8/DR3 phenotype was associated with high responsiveness to these mitogens. However, in the presence of the Gm1,17;..;21 haplotype subjects positive for HLA-B8/DR3 did not respond better to mitogenic stimulation than those lacking this HLA haplotype. Our results imply that the immunogenetic make-up of test persons should be taken into account in the assessment of the immune status of individuals or groups of patients.

Laboratory animal allergy--possible association with HLA B15 and DR4

In 101 laboratory technicians working with laboratory animals 30 presented laboratory animal allergy (LAA) symptoms. Twenty-seven of these LAA technicians were HLA tested. In these the HLA B15 and DR4 frequencies were raised.

Association of HLA-DR3 with human immune response to Lol p I and Lol p II allergens in allergic subjects

Associations between HLA type and IgE or IgG antibody (Ab) responses to two well-characterized, antigenetically non-crossreactive components of Lolium perenne (rye grass) pollen extract, Lol p I (Rye I) and Lol p II (Rye II) were studied in two groups of skin-test positive (ST+) Caucasoid adults. By both nonparametric and parametric statistical methods, significant associations were found between Ab responses to both Lol I and Lol II and the possession of HLA-DR3. In view of the well-known associations of both DR3 and B8 (which are in linkage disequilibrium) with many autoimmune diseases, differences in anti-Lol I and anti-Lol II mean log[Ab] levels between B8+, DR3- vs B8-, DR3- subjects and B8+, DR3+ vs B8-, DR3+ subjects were investigated. No differences were found. Our data, along with recent RFLP and DNA sequence studies, suggest that an Ia molecule involved in immune recognition of a similar major Ia recognition site of both the Lol molecules may consist of a DR3 alpha-beta I pair. Abbreviations used: Ab: Antibody. HLA: Human leukocyte antigen. Lol p I, Lol I: Group I allergen from Lolium perenne pollen (Rye I). Lol p II, Lol II: Group II allergen from Lolium perenne pollen (Rye II). Mr: Relative molecular mass. Rx: Immunotherapy with grass pollen extracts. ST: Skin test.