title: Influence of interleukin-4 gene polymorphisms and interleukin-4 serum level on susceptibility and severity of rheumatoid arthritis in Egyptian population.
abstract: BACKGROUND
  Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease in which interleukin-4 (IL-4) plays an important role. This study aimed to investigate the influence of IL-4 variable number of tandem repeats (VNTRs) and IL-4-590 promoter polymorphisms on RA susceptibility, activity and severity in Egyptian population.
  
  
  METHODS
  One hundred and seventy-two RA patients and 172 controls were enrolled in this study. IL-4 VNTR and IL-4-590 promoter polymorphisms were genotyped using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Serum IL-4 and anti-cyclic citrullinated peptides (anti-CCPs) antibody concentrations were measured by enzyme linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Subjects with IL-4-590 TT genotype were significantly more likely to develop RA. IL-4 VNTR 1/1 genotype, IL-4-590 TT and CT genotypes were significantly more associated with erosive RA and positive anti-CCP antibody. RA severity parameters were significantly increased, while, IL-4 level was significantly decreased in RA patients with IL-4 VNTR 1/1 and IL-4-590 TT genotypes. Only patients with IL-4-590 TT genotype showed a significant increase of all RA activity parameters.
  
  
  CONCLUSIONS
  IL-4 VNTR and IL-4-590 promoter polymorphisms may be helpful for assessing RA severity in Egyptian population. Moreover, IL-4-590 promoter polymorphism may be associated with increased risk and activity of RA.
authors: Medical Biochemistry Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt.
authors: Yousri M
authors: YM
authors: Hussein
authors: Amal S
authors: AS
authors: El-Shal
authors: Noha A
authors: NA
authors: Rezk
authors: Sahar M
authors: SM
authors: Abdel Galil
authors: Saad S
authors: SS
authors: Alzahrani
mesh_terms: D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000235:genetics* / Q000473:pathology; D016022:Case-Control Studies; D004534:Egypt; D020022:Genetic Predisposition to Disease; D006801:Humans; D015847:Interleukin-4 / Q000097:blood* / Q000235:genetics*; D007596:Joints / Q000473:pathology; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics; D010456:Peptides, Cyclic / Q000276:immunology; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012720:Severity of Illness Index
chemical_list: C508598:IL4 protein, human; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D015847:Interleukin-4