The relationship between C-reactive protein rs3091244 polymorphism and ankylosing spondylitis

Int J Rheum Dis. 2016 Jan;19(1):43-8. doi: 10.1111/1756-185X.12619. Epub 2015 Oct 20.


Aims: Previous studies have shown that C-reactive protein (CRP) gene polymorphism can be related to inflammatory changes. The present study aimed to examine the association between CRP gene polymorphism and clinical and laboratory findings in ankylosing spondylitis (AS) patients.

Materials and methods: A total of 80 patients, 40 with AS and 40 controls, were included in the study. Diagnosis of AS was made according to Assessment in AS International Working Group criteria. Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index and Bath Ankylosing Spondylitis Radiology Index scores were evaluated. CRP gene C, A and T alleles were evaluated and were determined using the analysis of melting curves after real time polymerase chain reaction. The odds ratios were calculated for all alleles and haploids of the CRP gene. We investigated the relationship between the CRP polymorphism and clinical and laboratory findings.

Results: A, C, T allele frequencies in the control group were 15%, 57.5% and 27.5%. The allele frequencies in the AS group were 38%, 68.8% and 26.2%. While C and T allele frequencies were shown to be similar in the two groups, A allele frequency was higher in the AS group compared to the control group. The CC wild allele was 42.5% in the control group and 47.5% in the AS group (P = 1.0). Odds ratios for the C allele were 1.6, for the CC haploid 1.2 and for the CT haploid 3.7. Chest expansion and finger-to-ground distance was better in the CRP gene polymorphism group compared to the no polymorphism group.

Conclusion: The presence of the CRP gene CC wild haploid and C allele in patients may indicate an increased risk for AS.

Keywords: CRP gene polymorphism; ankylosing spondylitis; clinical severity.

MeSH terms

  • Adult
  • C-Reactive Protein / genetics*
  • Case-Control Studies
  • Chi-Square Distribution
  • Female
  • Gene Frequency
  • Genetic Association Studies
  • Genetic Markers
  • Genetic Predisposition to Disease
  • Haplotypes
  • Heterozygote
  • Homozygote
  • Humans
  • Male
  • Odds Ratio
  • Phenotype
  • Polymorphism, Genetic*
  • Protective Factors
  • Real-Time Polymerase Chain Reaction
  • Risk Factors
  • Severity of Illness Index
  • Spondylitis, Ankylosing / diagnosis
  • Spondylitis, Ankylosing / genetics*
  • Spondylitis, Ankylosing / immunology


  • Genetic Markers
  • C-Reactive Protein