title: The effect of CD14 and TLR4 gene polymorphisms on asthma phenotypes in adult Turkish asthma patients: a genetic study.
abstract: BACKGROUND
  Endotoxins stimulate T helper 1 cell maturation and send a negative signal to T helper 2 polarisation. This causes a decrease IgE levels and prevents atopy (Hygiene hypothesis). It is shown that this response is under genetic control by polymorphisms in CD14 and TLR4 genes in some researchs. We aimed to investigate the effects of genetic variants of CD14 (-) and TLR4 (Asp299Gly, Thr399Ile) genes on asthma phenotypes in adults with asthma.
  
  
  METHODS
  Asthma patients (n = 131) and healthy control cases (n = 75) were included in the study. Relations between CD14 C-159 T, TLR4 299 and TLR4 399 genotypes and duration of asthma history of allergic rhinitis-dermatitis, total IgE, eosinophil, skin prick test, forced expiratory volume 1 (FEV1) and severity of disease were evaluated. Real time PCR (RT-PCR) was used for genotyping.
  
  
  RESULTS
  For CD14-159, presence of the C allele (CC + CT) was more frequent among those with low median log (logarithm) IgE levels, but no statistically significant difference in all asthma group (p = 0.09). C allele was significantly correlated with low total IgE levels and T allele with high total IgE levels in atopics (p = 0.04). CC + CT genotype was more frequent in moderate and severe asthma group in atopics (p = 0.049). TLR4 299 and TLR4 399 genotypes and asthma phenotypes were not found to be significantly correlated (p > 0.05).
  
  
  CONCLUSIONS
  Total IgE levels were found to be low among patients with the CC + CT genotype, and high among patients with the TT genotype contrary to the results of many other studies, which is therefore an important finding. Another important finding was that the C allele is a risk factor for moderate and severe asthma.
authors: Department of Chest Diseases, Yedikule Chest Diseases and Surgery Training and Research Hospital, Zeytinburnu/İstanbul, 34760, Turkey. fusunsahin19700@hotmail.com.
authors: Füsun
authors: F
authors: Sahin
authors: Pınar
authors: P
authors: Yıldız
authors: Ayşegül
authors: A
authors: Kuskucu
authors: Mert Ahmet
authors: MA
authors: Kuskucu
authors: Nilgün
authors: N
authors: Karaca
authors: Kenan
authors: K
authors: Midilli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000097:blood / Q000235:genetics*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D018950:Lipopolysaccharide Receptors / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011110:Polymorphism, Genetic; D051197:Toll-Like Receptor 4 / Q000235:genetics*; D014421:Turkey; D055815:Young Adult
chemical_list: D018950:Lipopolysaccharide Receptors; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D007073:Immunoglobulin E