The roles of Single Nucleotide Polymorphism (SNP) Endoplasmic Reticulum Aminopeptidase 1 (ERAP 1) gene in axial spondyloarthritis Indonesian adults.

BACKGROUND

Axial Spondyloarthritis (AxSpA) is chronic inflammatory arthritis involving the axial joint whose pathogenesis is related to the SNP ERAP1 gene, HLA B27, and cytokine proinflammatory (IL-17A and IL-23).

OBJECTIVE

Analyzed the role of SNP gene ERAP1 on disease activity and proinflammatory cytokines.

METHODS

This study comprised of two phases including a cross-sectional study and an in-vitro experiment in post-test with a control-group design. Participants underwent a PCR investigation searching for HLA-B27. Disease activities were measured by Ankylosing Spondylitis Disease Activity Score-Erythrocyte Sedimentation Rate (ASDAS-ESR) and modified Stokes Ankylosing Spondylitis Spinal Score (mSASSS). Subjects with HLA-B27 positive underwent PCR ERAP1 gene rs27434, genome-sequencing, and analysis. ELISA sandwich method was used to measure ERAP-1, IL-17, and IL-23 levels with lipopolysaccharide and IFN-γ induction. Analysis using independent t-test, Mann Whitney, and Pearson correlation test with p < 0.05.

RESULTS

The average ASDAS-ESR was 3.33 ± 0.89 and the average mSASSS was 26.53 ± 9.90. In HLA B27 positive group, SNP ERAP1 gene rs 27434 in which alleles A changed to G and A/G with genotypes AA to AG/GG was observed. SNPs of the ERAP1 gene had a correlation on mSASSS (r = 0.553; p < 0.05) and no correlation on ASDAS-ESR (r = 0.232; p = 0.235). There were significant differences observed in the SNP ERAP1 gene on ERAP1 and IL-17A levels in subjects with lipopolysaccharide and IFN-γ induction (p = 0.05) but no significant difference in IL-23 levels (p > 0.05).

CONCLUSION

The SNP ERAP1 gene affects mSASSS value, ERAP1 levels, and IL-17A levels whereas ASDAS-ESR value and IL-23 level were not associated.