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Association of IL-4 receptor polymorphisms with atopic asthma in Korean children
$128
Abstracts
J ALLERGY CLIN IMMUNOL FEBRUARY 2003
1,~ Association of Genetic Instability of Lymphocytes with
2~ ~ll~lllncreased IgE in Children Living in Areas of Belarus Contaminated with Cs137
L. P. Titov l, D. Charnashey I, E. Kirylchykl, P. Rytik ], S. Melnov I, L. M. Du Buske 2, H. C. Schroder 3, W. Muller3; IRIEM, Minsk, BELARUS, 2Immunology Research Insti" e of New England, Fitchburg, MA, 3Institute for Physiologische Chemie, Universitat Mainz, GERMANY. RATIONALE: Instability of the lymphocytic genome consequent to low levels of radiation exposure may induce re-arranging of genes due to DNA strand breakage. This investigation of lymphocytic genome instability and its relation to IgE formation focuses on children living in Cs137-contaminated territories of Belarus. METHODS: 209 children aged 5-15 were studied. The examination included DNA strand breakage index (DSBI) determined in lymphocytes by a recently developed "fast micromethod" which determines DNA breakage in freshly isolated lymphocytes by calculation of the ratio between the speed of control and sample DNA unwinding in highly alkaline conditions. A low or negative index indicates increased DNA breakage in the lymphocytes. IgE levels were determined by immunoassay. RESULTS: DNA breakage increased according to the degree of Csl37 contamination, the index falling from 0.235 - 0.02 to 0.027 _ 0.008 in areas with Cs137 radiation contamination of <5 Cu/km 2 and >16 Cu/km 2 respectively. DNA instability increased with the children's age and radiation exposure duration. In children from l 3-16Cu/km 2 contaminated areas DSBI indexes were 0.056 _+ 0.001; 0.03 ___0.007 and 0.016 _ 0.001 for children aged 5-10, I 1-15 and 16-l 7 years respectively. Analysis of DBSI and lgE levels revealed a significant negative correlation between DBSI and serum IgE level, ranging from -0.58 (p<0.05) to ~0.82 (p<0.02). CONCLUSIONS: (1) Low radiation exposure increases DNA instability in lymphocytes from children from Csl37 contaminated areas. (2) DNA breakage correlates with the degree of Cs137 contamination and duration of exposure to radiation. (3) DNA breakage correlates with serum lgE level, increased DNA instability being associated with increased lgE levels. Funding: EC ( FP5RTD), Grant of EC, Proposal No. ICA2-1999-10025
234 AfricanThe CD14(C-159T)AmeriFamiliesP~176 can
and Allergic Disease in
E. Ehrlieh, A. Zambelli-Weiner, M. Stockton-Porter, K. C. Barnes; Johns Hopkins University, Baltimore, MD. RATIONALE: Polymorphisms in candidate genes that bind endotoxin have been shown to be associated with allergic disease, especially CDI4, a cell surface antigen preferentially expressed on mature cells of the monocytic lineage. The CD 14(C- 159T) polymorphism has been associated with markers of asthma and atopy in several studies, none of which have focused on populations of African descent, despite the fact that this group suffers greater asthma morbidity/mortality than others. METHODS: To examine the frequency of CDI4(C-159T) in a population of African descent, genomic DNA was extracted from blood samples of 129 subjects and screened for CDI4(C-159T) using the PCR-RFLP technique following informed consent approved by the Johns Hopkins University IRB. RESULTS: The frequency of TT genotypes (5.5%) was much lower than that reported previously in populations with few or no subjects of African descent, and the CC genotype frequency was nearly doubled (55%). Frequency of C and T alleles among asthmatics were 74% and 26%, respectively. Among non-asthmatics, the allele frequency o f T increases to 29%, which is still lower than the frequency of -50% reported by others. CC homozygotes were more likely to be asthmatic compared to carriers of the CT and TT genotypes (OR=1.34), however this trend was not statistically significant (p<0.05). CONCLUSIONS: While allele frequencies are markedly different in this African American population compared to Caucasian populations reported elsewhere, the CDI4(C-159T) SNP may still be associated with asthma outcomes. Funding: NIH
35 Association of IL-4 Receptor Polymorphisms with Atopic Asthma in Korean Children S. Hong ], J. Kim I, B. Kim I, S. Choi 2, S. Lee2; 1Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, REPUBLIC OF KOREA, 2Asan Institute for Life Sciences, Seoul, REPUBLIC OF KOREA. RATIONALE: Atopy is major risk factor of the development of asthma. Interleukin-4 receptor ot (IL-4Re0 plays crucial roles for the binding and signal transduction of IL-4 and IL-13 which participate in IgE production. We investigated to determine whether IL-4R polymorphisms contribute to any susceptibility to atopic asthma or non-atopic asthma. METHODS: We conducted an association study of the known polymorphisms of 1L-4R (Ile50Val, Arg551Gln) with the atopic-asthma and nonatopic asthma in the Korean children. A hundred ninety-six atopic asthmatic children, 60 non-atopic asthma, and 100 non-atopic healthy children were enrolled. Asthma phenotypes were determined by a physician and bronchial responsiveness to methacholine, and genotypes of IL-4R polymorphisms were determined with PCR-RFLP method. RESULTS: The allele frequencies of Ile50Val polymorphism were not statistically different among atopic asthma, non-atopic asthma, and nonatopic healthy children and not associated with the clinical parameters of atopy. In the polymorphisms of Arg551 Gin of IL-4Ro~ gene, the frequency of Arg/Gln heterozygote and Arg/Arg homozygote in atopic asthma (27.6%) was significantly increased compared to that in non-atopic healthy children (16.0%). Total eosinophil count, eosinophil fraction (%), and D.fIgE concentration ofArg/Gln heterozygote and Arg/Arg homozygote were higher significantly than Gln/Gln homozygote in the polymorphisms of Arg551Gln 1L-4R~ gene, whereas bronchial responsiveness (PC20) was significantly low in the Arg/Gln heterozygote and Arg/Arg homozygote. CONCLUSIONS: These data suggest that the IL-4Rot 551Arg allele is associated with increased risk of atopic asthma in the Korean children. Funding: Grant from Asan h~stitutefor Life Sciences
236
Atopic Families
o, Allergen-Specific
Responses in
D, R. Jackola, L. K. Mullany, C. L. Liebeler, M. N. Blumenthal, A. Rosenberg; Asthma & Allergy Program, University of Minnesota, Minneapolis, MN. RATIONALE: Determine which of two models best describes allergenspecific humoral responses in atopy-prone families. I. Modulated Inheritance: obligate metabolic pathways involved with sensitivity to specific allergens. II. Stochastic Competition: response to allergen is primarily due to probabilistic elements impinging upon the humoral immune system. METHODS: A total of 1099 members of families with positive atopic history were evaluated (26 multi-generation and 112 nuclear families). Each was tested for sensitivity to t4 allergens by skin prick test (SPT). Five multi-generation families were tested for Amb a 1-specific IgE and IgG 1 responses (concentration and binding affinity), and Amb a 1 IgA and IgG subclass "concentration profiles." RESULTS: By Spearman rank correlation test, all but 3 families had comparable SPT results, suggesting that environmental exposure rather than allergen-specific inheritance determined the responses. Calculating conditional probabilities for 100 nuclear families, children's SPT outcomes were independent of their parent's SPT responses. The relative concentrations o f A m b a 1 lgAl&2 and lgGI-4 were comparable among atopics and non-atopics. However. atopics produced high affinity allergen-specific lgE and attenuated (low affinity) IgGl, whereas non-atopics produced high affinity allergen-specific IgG1. CONCLUSIONS: While the general propensity for atopy may be inherited, there is no evidence that sensitivity to specific allergens is inherited. Also, both atopics and non-atopics can mount vigorous humoral responses to allergens. An individual's specific atopic outcome is a stochastic variable independent of familial sensitization patterns. Thus, Model I1. Stochastic Competition best describes the propensity for allergen sensitization in atopy-prone families. Funding: NIH, American Lung Association. Minnesota Medical Foundation
Abstracts
J ALLERGY CLIN IMMUNOL FEBRUARY 2003
1,~ Association of Genetic Instability of Lymphocytes with
2~ ~ll~lllncreased IgE in Children Living in Areas of Belarus Contaminated with Cs137
L. P. Titov l, D. Charnashey I, E. Kirylchykl, P. Rytik ], S. Melnov I, L. M. Du Buske 2, H. C. Schroder 3, W. Muller3; IRIEM, Minsk, BELARUS, 2Immunology Research Insti" e of New England, Fitchburg, MA, 3Institute for Physiologische Chemie, Universitat Mainz, GERMANY. RATIONALE: Instability of the lymphocytic genome consequent to low levels of radiation exposure may induce re-arranging of genes due to DNA strand breakage. This investigation of lymphocytic genome instability and its relation to IgE formation focuses on children living in Cs137-contaminated territories of Belarus. METHODS: 209 children aged 5-15 were studied. The examination included DNA strand breakage index (DSBI) determined in lymphocytes by a recently developed "fast micromethod" which determines DNA breakage in freshly isolated lymphocytes by calculation of the ratio between the speed of control and sample DNA unwinding in highly alkaline conditions. A low or negative index indicates increased DNA breakage in the lymphocytes. IgE levels were determined by immunoassay. RESULTS: DNA breakage increased according to the degree of Csl37 contamination, the index falling from 0.235 - 0.02 to 0.027 _ 0.008 in areas with Cs137 radiation contamination of <5 Cu/km 2 and >16 Cu/km 2 respectively. DNA instability increased with the children's age and radiation exposure duration. In children from l 3-16Cu/km 2 contaminated areas DSBI indexes were 0.056 _+ 0.001; 0.03 ___0.007 and 0.016 _ 0.001 for children aged 5-10, I 1-15 and 16-l 7 years respectively. Analysis of DBSI and lgE levels revealed a significant negative correlation between DBSI and serum IgE level, ranging from -0.58 (p<0.05) to ~0.82 (p<0.02). CONCLUSIONS: (1) Low radiation exposure increases DNA instability in lymphocytes from children from Csl37 contaminated areas. (2) DNA breakage correlates with the degree of Cs137 contamination and duration of exposure to radiation. (3) DNA breakage correlates with serum lgE level, increased DNA instability being associated with increased lgE levels. Funding: EC ( FP5RTD), Grant of EC, Proposal No. ICA2-1999-10025
234 AfricanThe CD14(C-159T)AmeriFamiliesP~176 can
and Allergic Disease in
E. Ehrlieh, A. Zambelli-Weiner, M. Stockton-Porter, K. C. Barnes; Johns Hopkins University, Baltimore, MD. RATIONALE: Polymorphisms in candidate genes that bind endotoxin have been shown to be associated with allergic disease, especially CDI4, a cell surface antigen preferentially expressed on mature cells of the monocytic lineage. The CD 14(C- 159T) polymorphism has been associated with markers of asthma and atopy in several studies, none of which have focused on populations of African descent, despite the fact that this group suffers greater asthma morbidity/mortality than others. METHODS: To examine the frequency of CDI4(C-159T) in a population of African descent, genomic DNA was extracted from blood samples of 129 subjects and screened for CDI4(C-159T) using the PCR-RFLP technique following informed consent approved by the Johns Hopkins University IRB. RESULTS: The frequency of TT genotypes (5.5%) was much lower than that reported previously in populations with few or no subjects of African descent, and the CC genotype frequency was nearly doubled (55%). Frequency of C and T alleles among asthmatics were 74% and 26%, respectively. Among non-asthmatics, the allele frequency o f T increases to 29%, which is still lower than the frequency of -50% reported by others. CC homozygotes were more likely to be asthmatic compared to carriers of the CT and TT genotypes (OR=1.34), however this trend was not statistically significant (p<0.05). CONCLUSIONS: While allele frequencies are markedly different in this African American population compared to Caucasian populations reported elsewhere, the CDI4(C-159T) SNP may still be associated with asthma outcomes. Funding: NIH
35 Association of IL-4 Receptor Polymorphisms with Atopic Asthma in Korean Children S. Hong ], J. Kim I, B. Kim I, S. Choi 2, S. Lee2; 1Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, REPUBLIC OF KOREA, 2Asan Institute for Life Sciences, Seoul, REPUBLIC OF KOREA. RATIONALE: Atopy is major risk factor of the development of asthma. Interleukin-4 receptor ot (IL-4Re0 plays crucial roles for the binding and signal transduction of IL-4 and IL-13 which participate in IgE production. We investigated to determine whether IL-4R polymorphisms contribute to any susceptibility to atopic asthma or non-atopic asthma. METHODS: We conducted an association study of the known polymorphisms of 1L-4R (Ile50Val, Arg551Gln) with the atopic-asthma and nonatopic asthma in the Korean children. A hundred ninety-six atopic asthmatic children, 60 non-atopic asthma, and 100 non-atopic healthy children were enrolled. Asthma phenotypes were determined by a physician and bronchial responsiveness to methacholine, and genotypes of IL-4R polymorphisms were determined with PCR-RFLP method. RESULTS: The allele frequencies of Ile50Val polymorphism were not statistically different among atopic asthma, non-atopic asthma, and nonatopic healthy children and not associated with the clinical parameters of atopy. In the polymorphisms of Arg551 Gin of IL-4Ro~ gene, the frequency of Arg/Gln heterozygote and Arg/Arg homozygote in atopic asthma (27.6%) was significantly increased compared to that in non-atopic healthy children (16.0%). Total eosinophil count, eosinophil fraction (%), and D.fIgE concentration ofArg/Gln heterozygote and Arg/Arg homozygote were higher significantly than Gln/Gln homozygote in the polymorphisms of Arg551Gln 1L-4R~ gene, whereas bronchial responsiveness (PC20) was significantly low in the Arg/Gln heterozygote and Arg/Arg homozygote. CONCLUSIONS: These data suggest that the IL-4Rot 551Arg allele is associated with increased risk of atopic asthma in the Korean children. Funding: Grant from Asan h~stitutefor Life Sciences
236
Atopic Families
o, Allergen-Specific
Responses in
D, R. Jackola, L. K. Mullany, C. L. Liebeler, M. N. Blumenthal, A. Rosenberg; Asthma & Allergy Program, University of Minnesota, Minneapolis, MN. RATIONALE: Determine which of two models best describes allergenspecific humoral responses in atopy-prone families. I. Modulated Inheritance: obligate metabolic pathways involved with sensitivity to specific allergens. II. Stochastic Competition: response to allergen is primarily due to probabilistic elements impinging upon the humoral immune system. METHODS: A total of 1099 members of families with positive atopic history were evaluated (26 multi-generation and 112 nuclear families). Each was tested for sensitivity to t4 allergens by skin prick test (SPT). Five multi-generation families were tested for Amb a 1-specific IgE and IgG 1 responses (concentration and binding affinity), and Amb a 1 IgA and IgG subclass "concentration profiles." RESULTS: By Spearman rank correlation test, all but 3 families had comparable SPT results, suggesting that environmental exposure rather than allergen-specific inheritance determined the responses. Calculating conditional probabilities for 100 nuclear families, children's SPT outcomes were independent of their parent's SPT responses. The relative concentrations o f A m b a 1 lgAl&2 and lgGI-4 were comparable among atopics and non-atopics. However. atopics produced high affinity allergen-specific lgE and attenuated (low affinity) IgGl, whereas non-atopics produced high affinity allergen-specific IgG1. CONCLUSIONS: While the general propensity for atopy may be inherited, there is no evidence that sensitivity to specific allergens is inherited. Also, both atopics and non-atopics can mount vigorous humoral responses to allergens. An individual's specific atopic outcome is a stochastic variable independent of familial sensitization patterns. Thus, Model I1. Stochastic Competition best describes the propensity for allergen sensitization in atopy-prone families. Funding: NIH, American Lung Association. Minnesota Medical Foundation