Relation between frequency of asthma and IgE antibody levels against Dermatophagoides farinae and total serum IgE levels in schoolchildren

Oral mite anaphylaxis caused by mite-contaminated okonomiyaki/ pancake-mix in Japan: 8 case reports and a review of 28 reported cases

BACKGROUND

Anaphylaxis after the ingestion of foods contaminated with mites has recently been recognized. Case series and case reports thus far have shown that mite-contaminated wheat flour is the major cause of oral mite anaphylaxis. However, we have found 8 cases of oral mite anaphylaxis which were caused by mite-contaminated okonomiyaki-mix, a savory Japanese style pancake mix, in our hospital.

METHODS

In addition to our 8 cases, the databases of MEDLINE and ICHUSHI were systematically searched for patients with oral mite anaphylaxis in Japan.

RESULTS

Thirty-six patients including our 8 cases with oral mite anaphylaxis were identified. Thirty-four out of 36 cases (94%) ingested okonomiyaki or takoyaki, prepared at home using okonomiyaki-mix or takoyaki-mix which was previously opened and stored for months at ambient temperature. Microscopic examination of culprit mixes of 16 cases including our 1 case revealed contamination of mites such as Dermatophagoides farina (Der f) (5 cases), Tyrophagus putrescentiae (Tyr p) (4 cases), and Dermatophagoides pteronyssinus (Der p) (3 cases). The specific IgE to each mite is generally upregulated in these patients. Especially, the titers of specific IgE to Der p and Der f were more than class 2 in all cases.

CONCLUSIONS

Mite-contaminated flavored flour is the major cause of oral mite anaphylaxis in Japan.

House dust allergy and immunotherapy

HDM allergy is associated with asthma, allergic rhinitis and atopic dermatitis. In many countries childhood asthma is predominantly found in HDM-allergic children with their probability of developing disease being proportional to their IgE antibody titers and the early development of Th2 responses. While the pathogenesis is complex and increasingly linked to infection the immunologically-based allergen immunotherapy and anti-IgE antibody therapy are highly beneficial. Immunotherapy could be a short-term treatment providing lifelong relief but the current regimens depend on repeated administration of allergen over years. Immunological investigations point to a contribution of responses outside the Th2 pathway and multiple potential but unproven control mechanisms. Over half of the IgE antibodies are directed to the group 1 and 2 allergens with most of remainder to the group 4, 5, 7 and 21 allergens. This hierarchy found in high and low responders provides a platform for introducing defined allergens into immunotherapy and defined reagents for investigation.

Genetic factors in the treatment of bronchial asthma

Owing to the recent vast progress in analytical tools and procedures to elucidate the relationship between genes and diseases, many candidate genes leading to the development of bronchial asthma have been reported. However, the quantitative phenotypes of asthma, such as decrease in forced expiratory volume in the first second, serum hyper-IgE, bronchial hyperresponsiveness and blood hyper-eosinophilia, do not represent this disease completely. On the other hand, eosinophilic inflammation of the bronchial mucosa represents accurately the feature of bronchial asthma, although accurate quantification of its status is difficult. While the production of interleukin (IL)-5 in peripheral CD4(+) T cells probably correlates with eosinophilic inflammation of the airway, the effectiveness of anti-IL-5 antibody for the treatment of bronchial asthma is controversial. Since intervention with asthma-causing gene products may not be sufficient for the treatment of this disease, identification of therapy-responsive genes should become more important in the near future.

Large scale genotyping study for asthma in the Japanese population

Background

Asthma is a complex phenotype that is influenced by both genetic and environmental factors. Genome-wide linkage and association studies have been performed to identify susceptibility genes for asthma. These studies identified new genes and pathways implicated in this disease, many of which were previously unknown.

Objective

To perform a large-scale genotyping study to identify asthma-susceptibility genes in the Japanese population.

Methods

We performed a large-scale, three-stage association study on 288 atopic asthmatics and 1032 controls, by using multiplex PCR-Invader assay methods at 82,935 single nucleotide polymorphisms (SNPs) (1^st stage). SNPs that were strongly associated with asthma were further genotyped in samples from asthmatic families (216 families, 762 members, 2^nd stage), 541 independent patients, and 744 controls (3^rd stage).

Results

SNPs located in the 5' region of PEX19 (rs2820421) were significantly associated with P < 0.05 through the 1^st to the 3^rd stage analyses; however, the P values did not reach statistically significant levels (combined, P = 3.8 × 10^-5; statistically significant levels with Bonferroni correction, P = 6.57 × 10^-7). SNPs on HPCAL1 (rs3771140) and on IL18R1 (rs3213733) were associated with asthma in the 1^st and 2^nd stage analyses, but the associations were not observed in the 3^rd stage analysis.

Conclusion

No association attained genome-wide significance, but several loci for possible association emerged. Future studies are required to validate these results for the prevention and treatment of asthma.

Association of a lymphotoxin-alpha gene polymorphism and atopic asthma in Taiwanese children

BACKGROUND

The lymphotoxin-alpha (LT-alpha) gene is located on chromosome 6 (6p21.1-6p21.3) and it may regulate tumor necrosis factor (TNF) production. TNF is a potent cytokine in the airway inflammatory response. Polymorphisms of TNF-associated genes have been related to asthma. This study investigated an LT-alpha-Ncol polymorphism in the first intron of the LT-alpha gene (LT-alpha-Ncol*1 allele, as a variant type; and LT-alpha-Ncol*2 allele), which may predispose individuals to asthma and atopy.

METHODS

Polymerase chain reaction-based assays were performed to determine LT-alpha-Ncol genotypes among our subjects. A genetic case control analysis was then performed on 114 atopic asthmatic and 155 non-asthmatic unrelated children.

RESULTS

There was a statistically higher frequency of LT-alpha-Ncol*1 allele carriers (1/1+1/2) in the subjects with atopic asthma than in controls (OR=1.923; 95% CI = 1.061-3.484; p = 0.031).

CONCLUSION

The results indicate that LT-alpha-Ncol*1 may be a risk factor for atopic asthma in Taiwanese children.

ADAM33 polymorphisms are associated with asthma susceptibility in a Japanese population

BACKGROUND

Asthma is the most common chronic disorder in childhood, and asthma exacerbation is an important cause of childhood morbidity and hospitalization. Asthma is believed to be a complex disorder involving genetic and environmental factors, and several asthma susceptibility loci have been identified through genome-wide screening. A disintegrin and metalloprotease 33 (ADAM33) was the first asthma susceptibility gene to be discovered by positional cloning in 2002.

OBJECTIVE

The aim of the present study was to investigate whether single-nucleotide polymorphisms (SNPs) in ADAM33 are associated with childhood asthma in the Japanese population.

METHODS

Twenty-three ADAM33 SNPs were genotyped by fluorescence correlation spectroscopy with the use of DNA from 155 families (538 members) identified through children with atopic asthma. The transmission disequilibrium test (TDT) was performed for family-based association study.

RESULTS

TDT revealed that minor alleles of S+1, ST+4, and T2 SNPs were over-transmitted to asthma-affected offspring (P<0.05). According to the haplotype TDT, no haplotype of ADAM33 was transmitted preferentially to asthmatic offspring.

CONCLUSION

Our results confirm the involvement of ADAM33 in the development of childhood asthma among the Japanese.

Association between polymorphisms in the SPINK5 gene and atopic dermatitis in the Japanese

Atopy, which is characterized by increased levels of immunoglobulin E (IgE) against common environmental allergens, is considered the strongest predisposing factor for asthma and atopic dermatitis (AD). Mutations in the gene encoding serine protease inhibitor Kazal-type 5 (SPINK5) are responsible for Netherton syndrome, a rare skin disorder characterized by greatly elevated IgE levels with atopic manifestations. A recent study of Caucasian AD families showed that maternally derived alleles of the SPINK5 gene are associated with development of AD and asthma, suggesting the parent-of-origin effect for the development of atopic diseases in the SPINK5 gene. We studied the possible association of the SPINK5 gene for the development of atopic diseases by determining the genotypes of five polymorphisms in a Japanese population. Ttransmission disequilibrium tests revealed an association of SPINK5 polymorphisms with AD but not with asthma. Our data indicate that the SPINK5 gene is associated with AD across ethnicities.

Immunological findings in 3 dogs clinically diagnosed with allergic rhinitis

Three dogs clinically diagnosed with allergic rhinitis (AR) were examined for their immunological findings. House dust mites (HDM) such as Dermatophagoides farinae (DF) and D. pteronyssinus (DP) were identified as positive allergens in the 3 dogs with both intradermal skin test and serum antigen-specific IgE test. Lymphocyte blastogenic response of peripheral blood mononuclear cells (PBMCs) under stimulation with DF antigen in dogs with AR was higher than that in 4 healthy control dogs. Expression level of IL-4 mRNA in PBMCs obtained from the 3 AR dogs was higher than that in PBMCs obtained from 4 healthy control dogs before and after stimulation with DF antigen. Expression level of IFN-gamma mRNA in PBMCs was not different between the AR and control dogs before and after stimulation with DF antigen. These results suggested that allergic reaction to HDM antigen and T(H)2-type immune response were associated with the development of AR in 3 dogs examined in this study.

Candidate genes for atopic asthma: current results from genome screens

Atopic asthma is one of the most common childhood diseases in developed countries. Asthma is characterized by reversible airway obstruction, bronchial hyper-responsiveness, and airway inflammation. Atopy in childhood is considered the strongest predisposing factor for asthma. The etiology of asthma is complex and is thought to involve the interaction of multiple genes and a variety of environmental factors such as allergens and viral and bacterial infections. To identify genes conferring susceptibility for asthma and atopy, many genome-wide screens for asthma and its associated traits have now been carried out, and genetic linkage has been consistently identified in several regions. Several independent genome-wide screens found regions of linkage with asthma on chromosomes 5, 6, 11, 12, 13, 16 and 19, identifying candidate susceptibility genes including FCER1B, the IL-4 gene cluster, TNFalpha, HLA loci and others. However, the evidence for linkage is still only suggestive for most regions. In an effort to clarify the mechanism underlying the development of asthma, further studies utilizing new technologies and data from the Human Genome Project are ongoing. It is hoped that this accumulation of data will lead to improved genetic testing and assist in the development of new drugs.

Association between TNFA polymorphism and the development of asthma in the Japanese population

Tumor necrosis factor (TNF) is a proinflammatory cytokine that participates in the inflammatory reaction in patients with asthma. The TNFA and TNFB genes, which encode TNF-alpha and TNF-beta, respectively, are located within the region encoding the human major histocompatibility complex on chromosome 6p21.3, which showed linkage to atopic asthma in our genome-wide search. To determine whether polymorphisms in the 5' flanking region of the TNFA gene (-1031C/T, -863C/A, and -857C/T) and an NcoI polymorphism in the TNFB gene (LTA NcoI) are associated with the development of asthma, we performed transmission disequilibrium tests of families identified through children with atopic asthma. Genotypes of families were determined by polymerase chain reaction-based restriction fragment length polymorphism or SNaPshot analysis. Transmission disequilibrium tests of 144 asthmatic families revealed that transmission of the -857C allele and the -1031T-863C-857C haplotype in the TNFA gene to asthma-affected offspring occurred more frequently than expected (-857C allele, p = 0.0055; -1031T-863C-857C haplotype, p = 0.0002). Our results suggest that TNFA or nearby genes, including those in the major histocompatibility complex region, may contribute to the development of asthma in the Japanese population.

Association between a new polymorphism in the activation-induced cytidine deaminase gene and atopic asthma and the regulation of total serum IgE levels

BACKGROUND

Activation-induced cytidine deaminase (AICDA) is a recently identified RNA-editing deaminase that plays an important role in class-switching. Defects in AICDA result in a hyper-IgM phenotype and lack of IgG, IgA, and IgE in both human beings and mice.

OBJECTIVE

The aim of this study was to determine whether the AICDA gene is related to regulation of total serum IgE and development of atopic asthma.

METHODS

We screened for polymorphisms in the 5;-flanking and coding regions of the AICDA gene in subjects with atopic asthma and analyzed the effect of these polymorphisms on the development of atopic asthma and on total serum IgE levels in Japanese asthmatic families.

RESULTS

We identified 3 novel polymorphisms (5923A/G, 7888C/T, and 8578A/C) and 1 rare variant (Arg25Cys) in the AICDA gene. Transmission disequilibrium testing showed that the 7888C allele was transmitted preferentially to asthma-affected children (P =.007). Mean log [total serum IgE] levels of parents with the 7888C/7888C, 7888C/7888T, and 7888T/7888T genotypes were 2.12, 1.99, and 1.77, respectively, and a significant association was observed between the genotypes (P =.02). In RT-PCR experiments, we found 2 novel splice variants of AICDA, one lacking all of exon 4 (variant 1; 367 base pairs) and the other lacking the first 30 base pairs of exon 4 (variant 2; 453 base pairs). These variants were not associated with the 7888C/T polymorphism.

CONCLUSION

The 7888C/T polymorphism might be associated with the pathogenesis of atopic asthma and the regulation of total serum IgE levels.

Reactivity to intradermal injection of extracts of Dermatophagoides farinae, Dermatophagoides pteronyssinus, house dust mite mix, and house dust in dogs suspected to have atopic dermatitis: 115 cases (1996-1998)

OBJECTIVE

To compare reactivities to intradermal injection of extracts of Dermatophagoides farinae, Dermatophagoides pteronyssinus, house dust mite mix, and house dust in dogs suspected to have atopic dermatitis.

DESIGN

Retrospective study.

ANIMALS

115 dogs.

PROCEDURES

Records of all dogs suspected to have atopic dermatitis that underwent intradermal testing between October 1996 and July 1998 were reviewed. Reactivities to intradermal injection of crude mixed house dust mite (1:25,000 wt/vol) and crude house dust (25 PNU/ml) extracts were compared with reactivities to intradermal injection of individual extracts of D farinae and D pteronyssinus (1:50,000 wt/vol).

RESULTS

Ninety dogs were confirmed to have atopic dermatitis including 61 of the 69 dogs with positive reactions to either or both of the individual house dust mite extracts. Intradermal testing with the mixed house dust mite extract had sensitivity of 75%, specificity of 96%, and accuracy of 83%. Intradermal testing with the house dust extract had sensitivity of 30%, specificity of 93%, and accuracy of 56%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that use of crude mixed house dust mite and crude house dust extracts for intradermal testing in dogs is not as accurate a method of determining house dust mite hypersensitivity as is the use of individual D farinae and D pteronyssinus extracts mainly because of the high percentage of false-negative results. Extracts of individual house dust mites are recommended for intradermal testing of dogs suspected to have atopic dermatitis.

Cytokine responses to Der p 1 and Der p 7: house dust mite allergens with different IgE-binding activities

BACKGROUND

There is very limited information comparing T-cell responses to different house dust mite (HDM) allergens even though T cells are essential in the initiation and regulation of immunoglobulin (Ig) E synthesis and eosinophilia.

OBJECTIVE

To compare the level of T-cell proliferation and cytokine production to the group 1 and group 7 HDM allergens which are known to have different IgE-binding capabilities.

METHODS

Freshly isolated peripheral blood mononuclear cells (PBMC) from HDM-allergic and HDM-nonallergic donors were stimulated with the group 1 and group 7 allergens of Dermatophagoides pteronyssinus and the level of proliferation as well as IL-5 and IFNgamma production were measured.

RESULTS

The proliferative and IL-5 production to the group 1 and group 7 allergens were equivalent despite the group 7 allergen's lower frequency of IgE-binding. However more IFNgamma was produced to Der p 7 than to Der p 1, particularly for the nonallergic donors. As expected IL-5 production was much higher for PBMC from the allergic donors than for cells from nonallergics; however, there was no difference in the level of T-cell proliferation between the donor groups.

CONCLUSION

The relative importance of the individual HDM allergens is normally determined by measuring the frequency of IgE-binding to the allergen in sera from an allergic population. The equivalent increased IL-5 response of PBMC from allergic people to the group 1 and group 7 allergens despite the different IgE-inducing activity indicates that these allergens may be equally capable of contributing to an asthmatic response by inducing eosinophilia.

Significant evidence for linkage of mite-sensitive childhood asthma to chromosome 5q31-q33 near the interleukin 12 B locus by a genome-wide search in Japanese families

Childhood-onset asthma is frequently found in association with atopy. Although asthmatic children may develop IgE antibodies against variety of allergens, asthma is associated primarily with allergy to house-dust mites, molds, or other allergens. In this study, we conducted a genome-wide linkage search in 47 Japanese families (197 members) with more than two mite-sensitive atopic asthmatics (65 affected sib-pairs) using 398 markers. Multipoint linkage analysis was carried out for atopic asthma as a qualitative trait using the MAPMAKER/SIB program. We observed significant evidence for linkage with maximum lod scores (MLS) of 4.8 near the interleukin 12 B gene locus on chromosome 5q31-q33. In addition, suggestive evidence on 4q35 with MLS = 2.7 and on 13q11 with MLS = 2.4 was obtained. The other possible linkage regions included 6p22-p21.3 (MLS = 2.1), 12q21-q23 (MLS = 1.9), and 13q14.1-q14.3 (MLS = 2.0). Many of the linkage loci suggested in this study were at or close to those suggested by genome-wide studies for asthma in Caucasian populations. The present study suggests the contribution of the interleukin 12 B gene or nearby gene(s) to mite-sensitive atopic asthma and a considerable number of genetic variants common across Caucasians and Japanese populations contributing to asthma, although the relative importance of various variants may differ between the groups.

Immunoglobulin E antibody against environmental allergens in subjects with trimellitic anhydride-induced asthma

The purpose of this study was to assess the relationship between atopy and the development of occupational asthma as a consequence of exposure to trimellitic anhydride (TMA). A case-control study was performed, which comprised 16 employees identified as having TMA-induced asthma and 44 similarly exposed controls. Specific immunoglobulin E measurements in response to cat, dust mite, ryegrass, and ragweed antigens were performed. Fifty-six percent of cases and 29% of controls were found to be atopic (P = 0.098). We demonstrated that there was a trend toward employees with TMA asthma being more atopic than those without TMA asthma. Atopy as an assessment of risk for the development of TMA asthma is unlikely to be useful, although further investigation may be warranted.

Evidence for linkage between asthma/atopy in childhood and chromosome 5q31-q33 in a Japanese population

Susceptibility to the development of asthma and other atopic diseases is known to be associated with genetic components, and several candidate genes have been reported to be linked to atopy in Caucasian populations. We conducted a study of linkage between asthma and markers on chromosomes 5q31-q33 and 11q13 in 68 Japanese families (306 members) by affected sib-pair analysis. Families for the linkage study were ascertained through asthmatic children visiting the allergy clinic. The results provide supportive evidence for linkage between asthma and gene markers in or near the interleukin-4 (IL-4) gene, the IL-9 gene, and D5S393 on chromosome 5q31-q33 (p = 0.0013, p = 0.018, and p = 0.0077, respectively). Linkage between atopic phenotype and these genetic markers was also suggested (p = 0.006, p = 0.01, and p < 0.0001 for atopy, respectively). However, we failed to find evidence for linkage of asthma or atopy to the IgE high-affinity receptor gene on 11q13 (p > 0.1). These findings indicate that beyond ethnicity, there are specific loci that contribute to susceptibility to atopy on chromosome 5q31-q33. In addition, our findings suggest that loci on chromosome 5q31-q33 are linked to the development of asthma in childhood.

Immune response to food antigens: kinetics of food-specific antibodies in the normal population

The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to beta-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.

Distribution of IgE and IgG antibody levels against house dust mites in schoolchildren, and their relation with asthma

Although asthmatic patients are known to have increased levels of IgG antibody against house dust mite (HDM), it is not clear whether or not the presence of HDM-specific IgG antibody is associated with the etiological mechanism of asthma. To address this problem, we evaluated the relationship between HDM-specific IgG antibody levels and incidence of asthma in a general pediatric population. IgE and IgG antibody levels against Dermatophagoides farinae (Df) were examined by RAST and ELISA in a total of 722 randomly selected schoolchildren including 26 subjects with asthma, and the relative prevalence rates of asthma in this population were evaluated in relation to both Df-specific IgE and IgG levels. The incidence of asthma correlated not only with levels of Df-specific IgE, but also with those of Df-specific IgG. There was a significant correlation between Df-specific IgE and IgG levels both in the total population and in the asthmatic children. Because IgG and IgE responses occurred in parallel in this population, the clinical significance of HDM-specific IgG anti-body remains unclear. However, our findings have suggested that clinical expression of asthma in children is primarily dependent on their capacity to mount a immune response to HDM, which includes both IgE and IgG responses.

Comparisons of IgE, IgG, and IgG4 responsiveness to Dermatophagoides farinae in children by immunoblotting

Although asthmatic children are often sensitized to the house-dust mite (HDM) during early childhood, it is not clear what antigenic components are associated with the early immune response of these children. To investigate this problem, we evaluated IgE, IgG, and IgG4 antibody responses to Dermatophagoides farinae (Df) by immunoblotting among three groups of children: group I aged 0-4 years, group II aged 5-9 years, and group III aged 10-14 years. In the group I subjects, positive IgE-binding reactions to 15- and 25-kDa components were found in 76% and 44% of sera, respectively. Those to other components were generally low in frequency. In contrast, positive IgG-binding reactions to 15- and 25-kDa components were found in 44% and 24% of sera, and those to 30- and 110-kDa components in 48% and 88% of sera, respectively. Positive IgG4 reactions to 15- and 25-kDa components were found in 48% and 24%, respectively, and those to other components were very low. Positive IgE-binding reactions to these components gradually became more frequent with increasing age in groups II and III, while IgG and IgG4 reactivities were not markedly different in these age groups. These results suggest that the 15- and 25-kDa proteins of Df are important antigens associated with the initial IgE response to HDM in early childhood, while the 30- and 110-kDa proteins are associated with IgG and 15-kDa components with IgG4.

Total serum IgE in trimellitic anhydride-induced asthma

The objective of this study was to determine whether total serum IgE levels are elevated in workers with trimellitic anhydride-induced asthma as compared with anhydride-exposed workers without an occupational immunologic syndrome. Sera from 12 highly exposed workers with trimellitic anhydride-induced asthma, and from 31 similarly exposed workers without occupational immunologic disease, were assayed for total immunoglobulin E (IgE) levels by Total IgE II FAST analysis. The mean total IgE levels were 176.74 ng/mL and 34.55 ng/mL respectively. The difference between the two groups was statistically significant, but considerable overlap of IgE levels between groups was seen. In conclusion, although mean total IgE levels are significantly different between TMA-exposed workers with or without occupational asthma, the significant amount of overlap and poor sensitivity of the test preclude the use of this assay in the individual evaluation of these workers.

Effect of specific immunotherapy in Dermatophagoides pteronyssinus allergic children

The effect of immunotherapy on 21 Dermatophagoides pteronyssinus (Dpt)-sensitive patients (15 children with extrinsic asthma and six children with extrinsic asthma plus allergic rhinitis) aged 8.9 +/- 0.71 years was studied. Their subjective and objective respiratory symptom score was recorded before beginning and after the first year of immunotherapy. The respiratory subjective symptoms, such as cough day/night, running nose, sputum production, sneezing, shortness of breath at night and asthma attacks, decreased significantly from pretreatment level (P < 0.05). The objective symptoms, such as wheezing, dyspnea with prolonged expiration, sibilant rales and retractions score, gradually decreased during treatment (P < 0.01). Total eosinophil count decreased in 76.2% of patients after immunotherapy (P < 0.01). While total immunoglobulin E (IgE) decreased in 81% of patients and specific IgE for Dpt decreased in 90.5% of patients, specific IgG for Dpt increased in 76% of patient (P < 0.001). Our results suggested that rising IgG and falling IgE values do not always coexist in the patients who benefit from immunotherapy.

Crossreactivity of IgE antibody against Dermatophagoides farinae with Limulus polyphemus agglutinin

Crossreactivity of IgE antibody against Dermatophagoides farinae (Der f) with Limulus polyphemus agglutinin (LPA) was examined using RAST and immunoblot analysis. Of 40 Der f-sensitive asthmatic patients, 28 revealed a positive RAST reaction to LPA, while none of 20 Der f-insensitive hay fever patients showed this reaction. LPA-specific RAST levels of the 40 asthmatic patients correlated with their Der f-specific levels. The RAST reactivity to LPA was competitively inhibited by the addition of either soluble Der f or LPA, but not by the specific inhibitory sugar of sialic acid. LPA could also induce histamine release from leucocytes of Der f-sensitive asthmatic patients. IgE immunoblot analyses showed that the positive RAST sera for LPA had a strong IgE binding activity to the 30 kDa and 80 kDa components of Der f body extract, whereas gel filtration studies showed that the high molecular weight fractions above 150 kDa retained antigenic constituents associated with IgE reactivity to LPA. These results suggest that the antigenic materials of Dermatophagoides mites share some determinants with the haemagglutinin of horseshoe crabs.

PKU-related dysgammaglobulinaemia: the effect of diet therapy on IgE and allergic sensitization

The effect of diet on the development of immunoallergic signs and symptoms in children with phenylketonuria (PKU) was evaluated. Immunological indices of 58 children with PKU treated with diets were compared to the immunological indices of 58 healthy (non-PKU) children. In the PKU group, 39 children had been placed on diet therapy within the first month of life; 19 children had been placed on diet therapy after 6 months of age. Total circulating lymphocytes; CD3+, CD4+, CD8+ circulating lymphocytes; and serum IgA, IgM, IgG and total IgE levels were measured for each child. Skin prick tests were performed for common inhalant and food allergens. Every 3 months over the 2-year period of this study, the signs and symptoms of eczema, allergic rhinitis and asthma were recorded. The PKU group had lower IgG levels (p = 0.004) and higher total IgE levels (p = 0.0001) than the control group. Significantly lower IgE levels were found in children started on diet therapy within the first month of life compared with those started on diet therapy after 6 months of age (p = 0.0001). Allergic sensitization was significantly more frequent in the PKU group (24/58 vs 13/58, z = 2.00, p < 0.05), but no significant difference in the incidence of eczema and allergic rhinitis was found. Asthma was less frequent in the PKU group than in the control group (5/58 vs 14/58, z = 2.09, p < 0.05). Thus, diet appeared to prevent the development of immunoallergic signs and symptoms.

Relation between bronchial responsiveness to methacholine and levels of IgE antibody against Dermatophagoides farinae and serum IgE in asthmatic children

The relation between non-specific bronchial responsiveness and allergic sensitivity was evaluated in children with asthma. Bronchial responsiveness was determined by methacholine inhalation challenge test, and was expressed as a provocative concentration of methacholine causing a 20% fall in FEV1 (PC20). RAST titre for Dermatophagoides farinae and serum IgE level were evaluated as parameters of allergic sensitivity. When the PC20 values, RAST titres for D. farinae, and serum IgE levels of 47 asthmatic children and 16 normal controls were compared, the asthmatic children had significantly lower PC20 values and higher D. farinae-RAST titres and serum IgE levels than the normal controls. The correlation analyses in 47 asthmatic children have shown that there is no significant correlation between PC20 values and RAST titres for D. farinae (r = 0.04, P > 0.1) or between PC20 values and serum IgE levels (r = 0.03, P > 0.1). These results suggest that although both bronchial hyperresponsiveness and allergic sensitization may be in some way related to one another in children with asthma, the magnitude of allergic sensitization does not influence the degree of the non-specific bronchial responsiveness.

Methacholine inhalation challenge in children with idiopathic chest pain

Bronchial reactivity to inhaled methacholine (MCH) was evaluated in 32 patients with 'idiopathic' chest pain. Each pain was recurrent in nature. The incidence of cases with a provocative concentration causing a 20% fall in the forced expiratory volume in 1 sec (PC20) of 10 mg/ml or less was 62.5% (20 cases), while it was only 11.1% (three cases) in 27 healthy controls. Seventeen patients had no personal history of allergic diseases, elevated serum IgE level or positive house dust mite-specific IgE antibody. Among these 17, eight (47.1%) had a PC20 of 10 mg/ml or less, the incidence of which was also higher than that of the healthy controls. During the challenge, eight patients complained of chest pain similar to that experienced before. The present results indicate that bronchial hyper-reactivity is an important cause of 'idiopathic' chest pain. Patients with unexplained chest pain should be considered for inhalation challenge.

IgE hidden in immune complexes with anti-IgE autoantibodies in children with asthma

Serum levels of IgE, anti-IgE autoantibodies (Abs), and IgE/IgG anti-IgE immune complexes (ICs) were measured in 110 children with asthma and 90 healthy control children. Significantly enhanced levels of IgE/anti-IgE IC were detected in children with asthma. However, only a weak correlation was found between anti-IgE auto-Ab serum levels and the degree of lung function abnormalities in children with asthma. However, children with asthma with low serum IgE levels had elevated IC serum levels of IgE/anti-IgE auto-Abs, suggesting that IgE might be hidden within these ICs and is therefore not measurable in vitro. The significant elevation of IgE/anti-IgE IC serum levels raises the question whether IgE within ICs is neutralized or might still be involved in immunologic mechanisms responsible for clinical symptoms of bronchial asthma.

House dust mite sensitization in children and residential characteristics in a temperate region

House dust mite (Hdm) infestation used to be rare in Stockholm, but Hdm-sensitized children are now frequently observed, which probably indicates an increased infestation rate. This study was performed to elucidate determinants of Hdm sensitization in children living in the area. In a case-control study, 53 Hdm-sensitized children (cases), a group of non-Hdm-sensitized atopic children (N = 54), and a group of nonallergic neighborhood children (N = 53) were included. Mattress dust was analyzed with ELISA for content of Hdm allergens. Indoor humidity and temperature were measured, and questionnaire data were collected. Asthma was significantly more common in the Hdm-sensitized group than in the atopic control group. Hdm allergens were found in 40%, 19%, and 23% of the dust samples of the case group, atopic group, and neighborhood control groups, respectively. Only 15% of the dust samples of the Hdm-sensitized children contained Hdm allergens above the recommended threshold levels of sensitization of 2000 ng/gm of dust. Inadequate ventilation, which partly appeared to be a consequence of energy saving, appeared to be a risk factor for Hdm sensitization. This result may apply also to other temperate regions and suggests that the problem is preventable.