title: Investigation of IL-21 gene polymorphisms (rs2221903, rs2055979) in cases with multiple sclerosis of Azerbaijan, Northwest Iran.
abstract: BACKGROUND
  Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the Central Nervous System that is immunologically mediated in genetically susceptible individuals. IL-21, a cytokine produced by TCD4(+) cells, particularly by Th-17 cells, is believed to play an important role in the MS pathogenesis.
  
  
  OBJECTIVE
  This study was performed to investigate the impact of genetic polymorphisms in IL-21 gene on MS susceptibility and clinical profiles.
  
  
  METHODS
  Seventy Iranian patients with clinically definite relapsing-remitting MS and 110 age, sex and ethic matched controls were genotyped for IL-21 gene polymorphisms using PCR-RFLP method.
  
  
  RESULTS
  Our results showed that the IL-21 rs2221903 SNP is not polymorphic in our population. Also, the allelic and genotypic frequencies of the IL-21 rs2055979 did not differ significantly between the MS patients and controls (P = 0.413 and P = 0.565 respectively, and OR = 1.122, 95% CI = 0.79-1.87 for T allele). However, our results showed that IL-21 rs2055979 (G/T) T allele positive (TT+GT) MS patients had lower (PI ≤ 1.5) disease progression compared to rs2055979 T allele negative (GG) patients (P = 0.009).
  
  
  CONCLUSIONS
  Our results showed that no outstanding association exists between IL-21 alleles and susceptibility to MS. However, our clinical analysis showed significant association of IL-21 gene polymorphism with the progression of multiple sclerosis disease. Our results indicate that the G allele promotes, or the T allele protects against disease progression. To clarify the role of IL-21 rs2055979 in MS pathogenesis, further comprehensive studies with larger sample sizes among different ethnicity populations are recommended.
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Immunology Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Tohid
authors.initials: T
authors.lastname: Gharibi
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Tohid
authors.initials: T
authors.lastname: Kazemi
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Immunology Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Aliparasti
authors.affiliation: Neuroscience Research Center, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Farhoudi
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Shohreh
authors.initials: S
authors.lastname: Almasi
authors.affiliation: Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Rashedeh
authors.initials: R
authors.lastname: Dehghanzadeh
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Narges
authors.initials: N
authors.lastname: Seyfizadeh
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Immunology Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Neuroscience Research Center, Tabriz University of Medical Sciences Tabriz, Iran ; Department of Immunology, Tabriz University of Medical Sciences Tabriz, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Babaloo
keywords: Multiple sclerosis; interleukin-21; polymorphism; progression index