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EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 El-Damarany & Saleh TUMOR NECROSIS FACTOR ALPHA GENE POLYMORPHISM IN BRONCHIAL ASTHMA CHILDREN By Eman El-Masry El-Damarany* and Abla Saleh** Departments of *Medical Biochemistry, El-Minia Faculty of Medicine, and **Pediatrics, Cairo Faculty of Medicine ABSTRACT: Bronchial asthma is a common disease with multiple determinants that include genetic variation, environmental exposures, and gene–environment interactions. Tumor necrosis factor alpha (TNF-α) has a role in asthma and wheezing pathophysiology. Single nucleotide gene polymorphisms, may be important as genetic predisposition to increase the production of TNF-α. Aim: we aim to investigate whether genetic variation in TNF-α is associated with asthma and wheezing and whether the association is related to the severity of the disease and other epidemiological factors. Methods and Results: Frequencies of TNF-a 308G/A polymorphism were compared in 50 asthmatic children, 50 wheezy infants and 50 control school children. Genotype frequencies for the TNF-a 308 G/A OR were significantly more in asthmatic children from controls OR 0.4 95%CI (0.1 – 1.9) p <0.001 also a significantly higher frequency of the GA polymorphism in wheezy infant compared to the control group OR 0.2 95%CI (0.04 – 0.9) p <0.001.No association was found between the polymorphism and the severity of the disease, the total eosinophil count and total IgE in both groups. Conclusion: We can conclude that genetic variation in TNF- α may contribute to childhood asthma and wheezing, these findings may have implications for future early intervention studies by helping to identify infants and children at increased risk for wheezing and childhood asthma. KEY WORDS: TNF-α Asthma, wheezes. Single nucleotide polymorphism with inflammatory response that characterizes human asthma. One such mediator is tumor necrosis factor alpha (TNF-α), which has been implicated in asthmatic inflammation by a broad series of in vitro, ex vivo, in vivo and genetic studies2. INTRODUCTION: Epidemiological studies have firmly established a genetic component of asthma disease. However, the genes involved in asthma are still unknown and are likely to be numerous1. Asthma is recognized as a T-helper type 2 (Th2) disease with a particular profile of cytokine release, including interleukin 4 (IL4) and interleukin 5 (IL5). However, increasing evidence indicates that other cytokines, which were classically considered to belong to Th1-type profiles, are also associated Several lines of evidences indicate that high levels of TNF-α are directly linked to asthmatic complications. The bronchial epithelial, endothelial and smooth muscle cells are the primary targets of TNF-α. It causes 227 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 substantial damage in the normal bronchial epithelial cells and the bronchi of the allergic mouse model3. In severe bronchial allergic inflammation TNF-α dependent leakage of epithelial and endothelial cells may have severe pathophysiological conesquences4. In bronchial smooth muscle cells TNF-α dependent hyperplasia and vasoconstriction are important. El-Damarany & Saleh PATIENTS AND METHODS: Hundred and fifty children were enrolled in this study. They were divided into 2 main groups; the patient group (100) and the control group (50). the patient group was subdivided into two groups; group I included 50 infant wheezers up to, 2-yrs old admitted to the hospital with ≥2 episodes of persistent or recurrent wheeze; the other group II included 50 asthmatic children aged between 5–12 yrs. All asthmatic patients had the clinical symptoms and the physical examination compatible with asthma. The patients were classified according to disease severity as recommended by the National Institutes of Health Expert Panel Report9. The TNF- alpha gene is located within the class III region of the major histocompatibility complex (MHC) close to the HLA-B locus on chromosome 6p. A polymorphism in the promoter region of theTNF- alpha gene at nucleotide -308, relative to the transcription start site, may be important in determining the host TNFalpha response5. There are two alleles at the polymorphic site, TNF- alpha 308G (TNF1) and TNF- alpha -308A (TNF2). In normal populations, TNFalpha -308G homozygosity is the predominant genotype6. The TNF – 308A allele is of interest because it is associated with increased in vitro transcription of TNF and with increased TNF levels in stimulated human white blood cells7. A number of studies have tried to determine whether the polymorphism influences TNF-α expression or susceptibility to certain diseases. A recent review suggested that the TNF- alpha -308G/ Apolymorphism does have a small, but significant, functional effect, with the A allele being associated with higher constitutive and inducible levels of transcription for TNF-α than the G allele8. All patients were recruited from the outpatient department; Allergy Clinic: New Children Hospital; Cairo University. A full verbal and written explanation of the study was given to all family members; who gave their consent and participated in this study. Ethical approval was obtained from the institutional review board of each hospital. Fifty age, gender and socioeconomic matching controls were included in the study. Normal subjects answered negatively to a screening questionnaire for respiratory symptoms. All children were subjected to the following: o Complete clinical and physical evaluation. o Complete blood picture including peripheral blood eonsinophil count, measurement of total serum Ig-E and TNF polymorphisms were analyzed using PCR with sequence specific primers (SSP). The primers and protocols used were based on those described by Perrey et al.,10 The aim of the present study was to investigate the genetics of TNFα production in terms of the TNFalpha -308 and their relationship to childhood asthma and infant wheezing. 228 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 El-Damarany & Saleh Taq DNA polymerase. The amplification was accomplished by 35 cycles at 94°C for 30 s, 59°C for 30 s, 72°C for 30 s, and a final 10min extension at 72°C. After amplification, a 20-µl aliquot of digestion mixture containing 10 U of NcoI (New England BioLabs, Beverly, MA) was added to 20 µl of PCR product and incubated at 37°C for at least 4 h. The -308G/A alleles were differentiated by NcoI restriction digestion (G allele, 87 and 20 bp; A allele, 107 bp. Digested PCR fragments were subjected to agarose gel electrophoresis (2%) and visualized by ethidium bromide staining and UV transillumination (Fig.1). PROCEDURE: o DNA was extracted from peripheral blood leukocytes. Genotyping for the TNFα-G-308A polymorphisms in genomic DNA were analyzed by polymerase chain reaction-restriction fragment length polymorphism method. o The primers sequences were: antisense primer, 5' TCTCGGTTTCTTCTCCATCG-3' and sense primer, 5' ATAGGTTTTGAGGGGCATGG3'. The reaction conditions used were: 0.1 µg of genomic DNA in a total volume of 20 µl of reaction mixture containing 0.1 µM of each primer, 200 µM of each dNTP, 20 mM Tris -HCl (pH, 8.4), 50 mM KCl, 1.5 mM MgCl2, and 0.5 U of Figure 1: NcoI digestion for the TNF- alpha -308 polymorphism. M indicates 100 bp DNA molecular size marker. Lanes 1&2 are heterozygous (G/A); Lane 3 is homozygous mutant (AA), lanes 4&5 are homozygous wild types (GG). STATISTICAL METHODS: Data was summarized as mean±SD and percentage. NonParametric test (Mann Whitney U) was used for analysis of two quantitative variables as the data not symmetrically distributed. Chi Square was used for analysis of qualitative data. Logistic regression was also done for detection of risk factor of GA genotype in wheezy infant and adult asthma in relation to epidemiological and laboratory data. P-value was consider significant if ≤ 0.05 RESULTS: The study included two groups; group I included 50 infant wheezers with age range was 4-24 month (11.1±7.6), 10 males (20%) and 40 females (80%), 20% of patients had a history of atopic dermatitis, while 20% had a history of allergic rhinitis, history of parental asthma was positive in 40% of patients, 60% were exposed to passive smoking due to parental smoking, Family history of asthma was positive in 48% of patients. (Table 1) 229 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 The group II (asthmatic group) included 50 children whose age range was 2-12 years (7.8±3.1), 30 patients (60%) were suffering from mild persistent asthma, while the rest were suffering from moderate persistent asthma .Two patients had a history of atopic dermatitis and two patients had a history of allergic rhinitis. History of parental asthma was positive in 18 patients, 28 patients had a positive history of parental smoking, and only 32 patients had a positive family history of asthma. (Table 1) El-Damarany & Saleh between the 2 groups with the wheezy infant group (306.4±268.8) while the asthmatic group (390.4±165.3), p= 0.09, also no significant difference was found between the total IgE of both groups with the wheezy infant group (194.1±284.3) and asthmatic group (377.3±105.2), p= 0.2. A significant difference was found in the Hb, Ht (%) as well as MCV where the wheezy infant had a significantly lower Hb 8.3±1.2, Ht(%)26.1±3.4, MCV 60.9±6.8 compared to asthmatics Hb 10.5±1.5, Ht(%) 31.4±4.6, MCV 70.4±6.1, p =0.0001, 0.001, 0.0001 respectively. (Table 1) The total eosinophil count showed no significant difference Table I: Demographic and clinical data of patients VARIABLES Age Sex: (Males/ Females) Atopic Dermatitis:% Allergic Rhinitis: % Parental Asthma: % Passive Smoking: % Family History%: Disease Classification WHEEZY INFANT N = 50 11.1 ± 7.6 month 10/40 80% Negative 20% Positive 80% Negative 20% Positive 60% Negative 40% Positive 40% Negative 60% Positive 50% Negative 50% Positive Onset of disease <6 month: 42(84%) >6month 8(16%) CHILD ASTHMA N= 50 7.8 ± 3.1 year 26/24 96% 4% 96% 4% 64% 36% 44% 56% 36% 64% Mild persistent: 30 (60%) Moderate persistent: 20(40%) 306.4 ± 268.8 390.4 ± 165.3 Eosinophil count (mm3) Total IgE (IU/ml) 194.1±284.3 Hematological Data 8.3 ± 1.2 Hb (gm/dl) 26.1 ± 3.4 Ht (%) 60.9 ± 6.8 MCV *P-value is significant if ≤ 0.05 Genotype frequencies for the TNF- alpha -308 polymorphism for asthmatics and infant wheezers were 377.3 ± 105.2 10.5 ± 1.5 31.4 ± 4.6 70.4 ± 6.1 P-value 0.3 0.7 0.5 0.2 0.6 0.5 0.09 0.2 0.0001* 0.001* 0.0001* significantly different from controls (p<0.001; table2). GA polymorphism in the wheezy infant occurred in 68% 230 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 of patients compared to the control group which occurred in only 30% OR 0.2 95%CI (0.04 – 0.9), p<0.001, meanwhile, the asthmatic group showed a significant association with the GA polymorphism occurring in 60 % of patients compared to the 30% polymorphism of the control group OR 0.4 95%CI (0.1 – 1.9), p<0.001. Wheezy infants also showed a El-Damarany & Saleh significantly lower homozygosity GG in 28% of patients OR 6.3 95%CI (1.331.6), p<0.001 compared to the control group where homozygous allele GG occurred in 70 % of patients. Asthmatic patients showed the homozygous allele GG in 36% of patients compared to the control group 70 % OR 3.1 95%CI (0.6 –15.5), p<0.01. Table 2: Comparison between TNF genotype frequency of wheezy infants and children with asthma in relation to controls WHEEZY INFANT CHILD ASTHMA CONTROL N = 50 N = 50 N = 50 VARIABLES N (%) OR (95%CI) N (%) OR (95%CI) N (%) 2(4) NS 2(4 ) NS 0(0) AA 34(68)* 0.2(0.04 – 0.9) 30( 60)* 0.4(0.1 – 1.9) 15(30) GA 14(28)* 6.3(1.3- 31.6) 18( 36)* 3.1 (0.6 –15.5) 35(70) GG * P<0.001 Indicate a significant difference with controls, p –values reflect the whole ratio compared to control. In a logistic regression analysis we tested the association of the polymorphism GA with different epidemiological and laboratory data in wheezy infant (table 3). Neither the onset of wheeze nor the parental or the family history of asthma and the exposure to passive smoking was a risk factor for the polymorphism (P-value: 0.2, 0.8, 0.5, and 0.9 respectively). The polymorphism had also no effect on the total eosinophil count and the total serum IgE (P-value: 0.9 and 0.9 respectively). Table 3: Logistic regression for detection of risk factor of GA genotype in wheezy infant in relation to epidemiological and laboratory data. VARIABLES B 95% CI Odds ratio P-value 2.6764 0.1528 – 1382.6252 14.5333 0.2 Onset of wheeze (months) -3.1023 0.0 – 483 0.0449 0.9 Eosinophil 0.1 –3.1273 0.0 – 9673 0.0438 0.9 Total IgE 1.4151 0.1340 – 126.5336 4.1170 0.4 Parental atopic dermatitis -0.3160 0.0993 – 5.3519 0.7291 0.8 Parental asthma 0.0753 0.1507 – 7.7126 1.0782 0.9 Passive smoking -2.3807 0.0081 – 1.0592 0.0925 0.5 Family history o P-value is significant if ≤ 0.05. o B: is the estimated logit coefficient o Odds ratio = P/ (1-P). P is the probability that the event y occurs. o C.I: Confidence interval (it is an interval in which a true population parameters fall). o Dependant variables: GA genotype. 231 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 El-Damarany & Saleh respectively. Family smoking wasn’t a risk factor for the polymorphism (Pvalue: 0.8), nor was the polymorphism associated to the severity of asthma (Pvalue: 0.3) or the total eosinophil count and the total serum IgE (P-value: 0.9 and 0.9) respectively. We also tested the association of GA polymorphism with different epidemiological and laboratory data in children with asthma (table 4); the polymorphism was not associated with an early onset of wheeze (P-value: 0.9), or the parental and family history of asthma (P-value: 0.6 and 0.4) Table 4: Logistic regression for detection of risk factor of GA genotype in child asthma to epidemiological and laboratory data VARIABLES B 95% C-I Odds ratio P-value -50.0849 0.0 – 0.0 0.0 0.9 Onset of asthma (months) 0.1738 0.0 – 2686 1.1898 0.9 Eosinophil 0.2 0.1242 0.0162 – 79.0281 1.1322 0.9 Total IgE -0.05377 0.0634 – 5.3819 0.5841 0.6 Parental asthma 0.3061 0.1487 – 12.4055 1.3582 0.8 Passive smoking 0.8957 0.2921 – 20.5326 2.4492 0.4 Family history -1.1497 0.0367 – 2.7320 0.3167 0.3 Type of asthma o P-value is significant if < 0.05. o B: is the estimated logit coefficient o Odds ratio = P/ (1-P). P is the probability that the event y occurs. o C.I: Confidence interval (it is an interval in which a true population parameters fall). o Dependant variables: GA genotype polymorphisms in the TNF-α gene and childhood asthma and infant wheezing keeping us with some15-17 but not all studies18. DISCUSSION: Although environmental factors are clearly important determinants of asthma, numerous studies have revealed that asthma has a strong genetic component but does not follow monogenic patterns of inheritance11. For a long time, asthma has been known to cluster in families, and family studies were the first to suggest that the disease was genetically inherited. Many studies of respiratory conditions have focused on the G–308A polymorphism in the TNF gene because of its associations with inflammation and diseases, including asthma12-14. To further investigate the role of TNF in asthma occurrence, we examined the associations of TNF G– 308A polymorphism with asthma and infant wheezing. A definite relationship was found in our study between the gene Three explanations are possible for an association between a candidate gene and disease: 1) the candidate allele is the relevant mutation in the disease gene; 2) the allele is positioned very close to the disease gene (linkage disequilibrium); or 3) the association is due to confounding by the allele frequency being higher in population subgroups in which disease frequency is also higher (population admixture)19. The TNF-308A allele is a much stronger transcriptional activator than the more common G allele and is associated with higher TNF production .The TNF-308A allele leads to high binding affinity of 232 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 nuclear factors to the TNF promoter and gives a high level of gene transcription. Thus, observations from functional studies suggest that the TNF-308A allele is of biological significance20. El-Damarany & Saleh There is extensive linkage disequilibrium on chromosome 622. The TNF- α gene is located within the class III region of the MHC close to the HLAB locus. The MHC is the most polymorphic region of the genome and there is strong linkage disequilibrium within the MHC itself. Di-Somma et al.,12 suggested that the association of TNF- α 308A with asthma reflected linkage disequilibrium with genes influencing a specific immune response. Whilst studying haplotype and genotype combinations may give more useful results, if too many polymorphisms are included, the subgroups become so numerous that huge patient numbers are required, otherwise statistical evaluation becomes difficult. Diseases with a complex genetic origin, such as asthma, also may be characterized by pleiotropy (the same genotype has different phenotypes), genetic heterogeneity (the same phenotype results from different polymorphisms), and incomplete penetrance (the same polymorphism does not always produce the same phenotype) 19. For a candidate gene to potentially be important in the disease, a number of criteria must be met. First, the gene protein product must be relevant to the pathophysiology of the disease. Second, the gene must contain mutations within either the coding region or the regulatory regions controlling gene expression; these mutations need to be functionally relevant. Third, functionally relevant mutations should demonstrate association and/or linkage with an appropriate phenotype19. The contrasting findings reported in some of the published asthma studies, may be related to number of potential reasons for the discrepancies. First Many of the published asthma studies are from quite different population groups, which could account for some of their different findings, as the prevalence of polymerphisms within different racial groups is often markedly different21 .Comparisons of findings between different ethnic groups may be irrelevant due to population-specific masking of gene variant effects, or gene-environment interactions specific to one population22. Another problem with genotype patient studies is that of assessing whether any association found with a disease state is genuine or whether it is due to linkage disequilibrium. This is the phenomenon whereby combinations of alleles occur together more or less often than expected by chance alone, due to their positions relative to each other on the gene. Any association found with a particular polymorphism may then be due to a nearby polymorphism, which is in linkage disequilibrium with the one under scrutiny. In our study polymorphism was also found to be associated with infant wheezing. We found a marked increase in the proportion of TNF- α 308GA in the wheezy infants (with a corresponding deficit of GG). Although the current authors have no explanation for this finding, it is believed to be a genuine (biological) rather than genotyping error. Azevedo et al.,23 demonstrated that alveolar macrophages from infants with recurrent episodes of wheezing, spontaneously generate increased amounts of TNF- α when compared to controls suggesting the presence of an ongoing activation of alveolar macrophages in the airways of wheezy infants, even during asymptomatic periods. Our results are the same like Biolikar et al.,6 another study by Zhu et al.,24 looked at this young age group, found, in contrast, that TNF- α 308A was not a risk factor for 233 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 the development of asthma by 12 months of age in 373 Canadian infants from atopic families .The reason for this variance may relate to the fact that only 12 out of 281 (4%) of their infants were labeled as having "probable asthma". Therefore, the numbers are rather small for significant differences to be found. El-Damarany & Saleh Other inflammatory exposures and conditions have the potential to confound the relationship between the TNF–308 polymorphisms and asthma. Some that have been well described in the literature include active personal smoking, exposure to second-hand smoke, indoors allergens, allergic diseases, and family history of asthma. Because of the consistent association between parental smoking and childhood asthma and the involvement of TNF in cigarette smoke–induced inflammation responses28, we examined the association of TNF-α single nucleotide polymerphism with asthma stratified by exposure to a smoking parent in the home. Exposure to tobacco smoke was assessed using questionnaire responses about household sources and was not validated by objective measurements such as nicotine levels. However, the validity of exposure estimates based on questionnaire responses has been investigated and found to provide reasonably valid estimates of exposure for adjustment for confounding29. We encountered that cigarette smoking wasn’t a risk factor for the polymorphism, a study by Hao Wu et al.,30 where the association was greater among children without smoking parents in the home. A recent study showed that the TNF-308 polymorphism modified the effect of home exposure to smokers on respiratory illness-related school absence among children mostly without asthma31. A possible explanation for the association of TNF polymorphisms with asthma predominantly for children without smoking parents is that the exposure to secondhand smoke, which increases TNF production, overwhelms the smaller impact of TNF polymerphisms on TNF expression. Indeed, expression levels of TNF are signifycantly increased in mice and humans exposed to tobacco smoke28. These environmental triggers may have synergistic effects and overcome the smaller effects of TNF polymorphisms. We also tested the effect of the GA polymorphism on the severity of the disease; the possibility of a particular association was examined for at least two reasons. The first is that such an association has been recently described for a subgroup of severe inflammatory bowel disease, the pathogenesis of which may somehow resemble that of asthma25. Secondly the inflammatory picture within the airways of asthmatics, involving both eosinophil and neutrophil (as opposed to the eosinophils alone in the mild to moderate forms of the disease) fits with a role for TNF- α that favors the tissue recruitment of both type of granulocytes partly through endothelial expression of intercellular adhesion molecule (ICAM)26. We studied the mild versus the moderate asthmatic children and our results fail to show any preferential association between TNF2 and the severity of asthma, however our study didn’t include patients with severe asthma like other reports14 which studied two grades of asthma severity (mild/ moderate versus severe) and failed to elicit any association. Chagani et al.,27 found that the TNF-α 308A polymorphism was not significantly more prevalent in 159 adults with fatal or near fatal asthma compared with 92 with mild or moderate asthma. It is perhaps not surprising that the severity of asthma is not associated with these TNF gene polymorphisms given the multiple complex factors that determine the severity of disease in any individual. 234 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 Conversely, in the absence of secondhand smoke exposure, the influence of TNF functional polymorphisms on TNF expression may be greater, which could explain our finding of stronger associations at lower levels of exposure. These results suggest that the effects of genetic variation in TNF may be more apparent at lower levels of exposure to substances such as secondhand smoke, which strongly influence TNF expression. El-Damarany & Saleh risk may be important for future early intervention studies. Studying gene polymorphisms may aid understanding of the pathophysiology of childhood wheezing, but an overriding question is whether there will be any practical or clinical use for it, and particularly whether it will be useful for an individual child. Most infant wheezers grow out of their condition in early childhood but some will end up diagnosed with genuine asthma. It has been suggested that early intervention with inhaled corticosteroids may prevent the development of asthma33 but clearly it would be pointless to treat all wheezy infants as in most cases the condition will resolve spontaneously34. Therefore, an identifiable marker that would indicate whether an infant is likely to develop genuine asthma would be most useful. Perhaps this is where the study of TNF alpha and other gene polymerphisms might have a role. Time and further studies might shed light on this area. The strategy for identifying candidate genes offers opportunities to further specify persons at increased risk for susceptibility to allergic sensitization (atopy), inflammation, bronchial hyper reactivity, and severity of asthma symptoms. Confirming the importance of candidate asthma genes will enable development of new diagnostic and therapeutic tools and of prevention and allergen avoidance strategies. Identification of candidate genes for asthma will also permit more precise elucidation of environmental risk factors operating at different stages of asthma development. The TNF-308 polymorphism has been frequently studied in asthma and atopy association studies because it has direct functional effects on TNF gene regulation. Our present data didn’t demonstrate the polymorphism to be associated with abnormally high eosinophil count or elevated total serum IgE, a phenotype previously shown to be linked to a mutation in the gene of FcR-l. Our results are similar to those by Louis et al.,1 Shin et al., 32 found no significant associations were detected between the polymorphism and peripheral blood eosinophil percentage (%). In his analyses of the association of TNF- α polymorphisms with total serum IgE levels, no significant associations were detected, however homozygous minor allele for TNFB+252A>G has been associated with increased IgE. The TNFα polymorphism probably acts by enhancing the inflammatory process rather than modifying the IgE-mediated allergic response. CONCLUSION: In conclusion, it was found that genotype frequencies (%) of GA polymorphisms that affected TNF-α gene in wheezy infant and adult asthma were significantly higher com-pared to the control group, however it did not seem to be related to the severity of asthma or the exposure to parental smoking or with the atopic state of the patients. Identification of certain high- REFERENCES: 1. Louis R, Leyder E, Malaise M, Louis L, et al., Lack of association between adult asthma and the tumour necrosis factor alpha-308 polymor-phism gene. Eur Respir J. 2000; 16(4):604-608. 2. Hyoung DS, Byung LP, Lyoung HK, Hoe JW, Young JK, et al., Tumor 235 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 necrosis factor polymorphisms and serum total IgE. Hum Molec Genet, 2005; 23(2): 39-40. 3. Srirupa M, John R H and Tapan K M. Role of TNF-α in pulmonary pathophysiology. Respir Res. 2006; 7(1): 125-129. 4. Tillie-Leblond I, Guery BP, Janin A, Leberre R, et al., Chronic bronchial allergic inflammation incr-eases alveolar liquid clearance by TNF-alpha-dependent mechanism. Am J Physiol Lung Cell Mol Physiol. 2002; 283:L1303– L1309. 5. Kroeger KM, Carville KS, and Abraham LJ. The –308 tumor necrosis factor-alpha promoter polymorphism effects transcription. Mol Immunol 1997; 34: 391–399. 6. Bilolikar H, Nam AR, Rosenthal M, Davies JC, et al., Tumor necrosis factor genepolymorphisms and childhood wheezing. Eur Respir J 2005; 26: 637–646 7. Messer G, Spengler U, Jung MC, Honold G, et .al. Polymorphic structure of the tumor necrosis factor (TNF) locus: an NcoI polymorphism in the first intron of the human TNF-ß gene correlates with a variant amino acid in position 26 and a reduced level of TNF-ß production. J Exp Med 1991, 12:79-105. 8. Wilson AG, Symons JA, McDowell TL, McDevitt HO, and Duff GW. Effects of a polymorphism in the human tumor necrosis factor-α promoter on transcriptional activation. Proc Natl Acad Sci USA 1997; 94:3195–3199 9. National Institutes of Health. Expert panel report on guidelines for diagnosis and management of asthma. Bethesda, Md: National Heart, Lung, and Blood Institute Information Center; 1997. 10. Perrey C, Turner SJ, Pravica V, Howell WM, and Hutchinson IV. ARMS-PCR methodologies to determine IL-10, TNF-a, TNF-b and TGF-b1 gene polymorphisms.Transpl Immunol 1999; 7: 127–128. El-Damarany & Saleh 11. Bleecker ER, Postma DS, Meyers DA. Evidence for multiple genetic susceptibility loci for asthma. Am J Respir Crit Care Med 1997; 156:S113–S116. 12. Di Somma C, Charron D, Deichmann K, Buono C, et al., Atopic asthma and TNF-308 alleles: linkage disequilibrium and association ana-lyses. Hum Immunol 2003;64:359–365 13. Mitsuta K, Matsuse H, Fukushima C, Kawano T, et al., Production of TNF-alpha by peripheral blood mononuclear cells through activation of nuclear factor kappa B by specific allergen stimulation in patients with atopic asthma. Allergy Asthma Proc 2003; 24:19–26. 14. Noguchi E, Yokouchi Y, Shibasaki M, Inudou M, et al., Association between TNFA polymerphism and the development of asthma in the Japanese population. Am J Respir Crit Care Med 2002;166:43–46. 15. Winchester EC, Millwood IY, Rand L, Penny MA, et al.,. Association of the TNF-α 308 (G-->A) polymorphism with self-reported history of childhood asthma. Hum Genet 2000; 107:591–596. 16. Wang TN, Chen WY, Wang TH, Chen CJ, et al., Gene-gene synergistic effect on atopic asthma: tumour necrosis factor-alpha-308 and lymphotoxinalpha-NcoI in Taiwan's children. Clin Exp Allergy 2004; 34:184–188. 17. Witte JS, Palmer LJ, O'Connor RD, Hopkins PJ, Hall JM. Relation between tumour necrosis factor polymorphism TNFalpha-308 and risk of asthma. Eur J Hum Genet 2002; 10:82– 85. 18. Buckova D, Holla LI, Vasku A, Znojil V, et al.,. Lack of association between atopic asthma and the tumor necrosis factor alpha-308 gene polymorphism in a Czech population. J Investig Allergol Clin Immunol 2002; 12:192–197 236 EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 El-Damarany & Saleh α and angiotensin converting enzyme polymorphisms in mild/moderate and fatal/near-fatal asthma. Am J Respir Crit Care Med 1999;160:278–282 28. Churg A, Wang RD, Tai H, Wang X, et al., Macrophage metalloelastase mediates acute ciga-rette smoke-induced inflammation via tumor necrosis factor-alpha release. Am J Respir Crit Care Med. 2003; 167:1083– 1089 29. Committee on the Assessment of Asthma and Indoor Air. Clearing the air: asthma and indoor exposures. Washington, DC: National Academy of Sciences; 2000. 30. Hao W, Isabelle R, Juan-Jose S, Blanca E. Parental Smoking Modi-fies the Relation between Genetic Variation in Tumor Necrosis Factor-α (TNF-α) and Childhood Asthma. Envi-ron Health Perspect.2007;115(4):616–622. 31. Wenten M, Berhane K, Rappaport EB, et al., TNF-308 modi-fies the effect of second-hand smoke on respiratory illness-related school absences. Am J Respir Crit Care Med. 2005;172:1563–1568 32. Shin HD, Park BL, Kim LH, Jung JH. Association of tumor necrosis factor polymorphisms with asthma and serum total IgE Human Molecular Genetics, 2004, 13 ( 4): 397-403 33. Pedersen S. Early use of inhaled steroids in children with asth-ma. Clin Exp Allergy 1997;27:995–999 34. Warner JO. The down-side of early intervention with inhaled corticosteroids. Clin Exp Allergy 1997;27:999– 1001 19. Michael BB, Kathleen B, Elizabeth T, David CC, et al.,. Genetic and Perinatal Risk Factors for Asthma Onset and Severity: A Review and Theoretical Analysis Epidemiologic Reviews 24:176-189 (2002). 20. Babu KS, Davies DE, Holgate ST. Role of tumor necrosis factor alpha in asthma. Immunol Allergy Clin North Am. 2004; 24:583–597. 21. Hall I. Candidate gene studies in respiratory disease: avoiding the pitfalls. Thorax 2002; 57:377–378. 22. Bayley JP, Ottenhoff TH, Verweij CL. Is there a future for TNF promoter polymorphisms? Genes Immun 2004; 5:315–329. 23. Azevedo L, de Blic J, Dumarey CH, Scheinmann P. Increased spontaneous release of tumour necrosis factor-αby alveolar macrophages from wheezy infants Eur Respir J 1997; 10: 1767–1773 24. Zhu S, Chan-Yeung M, Becker AB, et al., Polymorphisms of the IL-4, TNF-α, and Fc RIß genes and the risk of allergic disorders in at-risk infants. Am J Respir Crit Care Med 2000; 161:1655– 1659 25. Louis E, Peeters M, Franchimont D, et al., Tumor necrosis factor gene polymorphism in Crohn's disease: influence on disease beha-viour? Clin Exp Immunol 2000;119: 64-68. 26. Lukacs NW, Strieter RM, Chensue SW, Widmer M, et al., TNFalpha mediates recruitment of neutronphilsand eosinophils during airway inflammation. J Immunol 1995; 154: 5411-54517. 27. Chagani T, Pare PD, Zhu S, et al., Prevalence of tumor necrosis factor- 237 El-Damarany & Saleh EL-MINIA MED., BULL., VOL. 20, NO. 1, JAN., 2009 تعدد األشكال الجينية لعامل النخر الورمي-ألفا في األطفال المصابين بالربو الشعبي إيمان المصري الدمراني* – عبلة صالح** أقسام *الكيمياء الحيوية الطبية -كلية طب المنيا - و**األطفال -كلية طب القاهرة يعتبر الربو الشعبي من األمراض الشائعة ذات العوامل المتعددة والتيي تشيمل اتاليتال اليينيي ,التعرض للعوامل البيئية وتداالل عوامل البيئة والوراثية ويلعيب عاميل النالير اليورمي دورا يي اإلحداث المرضي للربو الشعبي. َحري عما إذا كان اتالتال الييني الوراثي ِ ي عامل النالر والغرض من هذه الدراسة هو الت ّ الييورمي يتييرت َب ت ط بييالربو و أزيييز التيينفع و عمييا إذا كييان هييذا اترتبيياط يتعل ي بحييدة المييرض والعوام ِل الوبائية األالرى. وقد قورنيت تيرددات الشيكل المتعيدد لعاميل النالير يي المسيين طفيا مريابين بيالربو الشيعبي و المسين رضيعا مرابين بأزيز التنفع باإلضا ة إلي المسيين تلمييذ مدرسية كميموعية ضيابطة. هذا وقيد وييد أن تيرددات البنيية اليينيية لعاميل النالير اليورمي كانيت أكثير يي مرضيي الربيو الشعبي عنها يي الميموعية الضيابطة وكيذل يي ميموعية أزييز التينفع عنهيا يي الميموعية الضابطة ولم يويد ارتباط بين تعدد الشكل الييني و حيدة الميرض والعيدد الكليي للالاييا المحبية لارطباغ باأليوسين والبروتين المناعي()IgE ومن هذه الدراسة َيستنت تج أ َ ْن اتالتال الييني الوراثي ِ قي عامل النالر الورمي قَي ْد يتسياه تم يي ت التييد ّال ِل المب ّكيير ِة ربييو الطفوليي ِة و أزيييز التيينفع ل وهييذه النتييائجِ لَ تربومييا لَهييا مضييمون لدِراسييا ِ الالطير المتزايي ِد لربيو الطفوليةَ و أزييز عدَة لت َميييز الرضيا واألطفيا ِل مين ذوي سيا َ المستقبلي ِة بال تم َ ِ التنفع. 238