Effect of MPG gene rs2858056 polymorphism, copy number variation, and level of serum MPG protein on the risk for rheumatoid arthritis

Polymorphisms in DNA Repair Genes and Association with Rheumatoid Arthritis in a Pilot Study on a Central European Population

Rheumatoid arthritis (RA) is a chronic, multifactorial autoimmune disease characterized by chronic arthritis, a tendency to develop joint deformities, and involvement of extra-articular tissues. The risk of malignant neoplasms among patients with RA is the subject of ongoing research due to the autoimmune pathogenesis that underlies RA, the common etiology of rheumatic disease and malignancies, and the use of immunomodulatory therapy, which can alter immune system function and thus increase the risk of malignant neoplasms. This risk can also be increased by impaired DNA repair efficiency in individuals with RA, as reported in our recent study. Impaired DNA repair may reflect the variability in the genes that encode DNA repair proteins. The aim of our study was to evaluate the genetic variation in RA within the genes of the DNA damage repair system through base excision repair (BER), nucleotide excision repair (NER), and the double strand break repair system by homologous recombination (HR) and non-homologous end joining (NHEJ). We genotyped a total of 28 polymorphisms in 19 genes encoding DNA repair-related proteins in 100 age- and sex-matched RA patients and healthy subjects from Central Europe (Poland). Polymorphism genotypes were determined using the Taq-man SNP Genotyping Assay. We found an association between the RA occurrence and rs25487/XRCC1, rs7180135/RAD51, rs1801321/RAD51, rs963917/RAD51B, rs963918/RAD51B, rs2735383/NBS1, rs132774/XRCC6, rs207906/XRCC5, and rs861539/XRCC3 polymorphisms. Our results suggest that polymorphisms of DNA damage repair genes may play a role in RA pathogenesis and may be considered as potential markers of RA.

Rheumatoid arthritis is associated with rs17337023 polymorphism and increased serum level of the EGFR protein

Objective

We have previously described the association of rheumatoid arthritis (RA) prevalence and two epidermal growth factor receptor (EGFR) SNPs (rs17337023 and rs2227983) among the Taiwanese population. This present study aimed to elucidate whether the SNPs can alter the expression of EGFR in the progression of RA.

Methods

The cohort study included 366 Taiwan’s Han Chinese RA patients and 326 age and gender matched healthy controls. Blood samples collected from the participants were analyzed to determine their serum EGFR levels and to identify EGFR SNPs from their genomic DNA. Genotyping for EGFR SNPs was performed by restriction fragment length polymorphism (RFLP) assay. The relationship between EGFR SNP and the clinical manifestations of RA was evaluated.

Results

Our results showed that a statistically significant difference in genotype frequency distributions at rs17337023 SNP for RA patients and controls (p ˂ 0.05). In addition, compared with the haplotype frequencies between case and control groups, the RA patient with the GT haplotype appeared to be a significant “protective” haplotype compared with other haplotypes (OR: 0.73, 95% CI: 0.59–0.91; p = 0.005). Furthermore, the increased serum level of EGFR was also observed in RA patients (p ˂ 0.001).

Conclusion

Our study showed that RA is associated with rs17337023 SNP in EGFR gene and increased serum level of the EGFR protein. These findings suggest EGFR is worthy of further investigation as a therapeutic target for RA.

Lectin, galactoside-binding, soluble, 3 rs4652 A/C gene variation and the risk for rheumatoid arthritis

Rheumatoid arthritis (RA) is a complex genetic disease. The lectin, galactoside-binding, soluble, 3 (LGALS3) gene, encodes a member of the galectin family of carbohydrate binding proteins, and is one of the best examples of a non-human leukocyte antigen gene associated with a risk for RA in various populations. In the current study, the association between LGALS3 rs4652 gene polymorphism and RA was examined. This case-control study was performed on the 120 patients with RA and 120 healthy subjects. Genomic DNA was extracted from whole blood, and gene polymorphism was tested using a tetra-primer amplification refractory mutation system-polymerase chain reaction. The results demonstrated that LGALS3 rs4652 AC genotype increased the risk of RA (OR=11.622, 95% CI=4.473-28.656; P=0.001) when compared with the AA genotype. However, the CC genotype and the C allele were not associated with RA. These findings indicated an association between LGALS3 rs4652 variation and the risk of RA in a sample of Iranian individuals. Further studies with larger sample sizes and populations of different ethnicities are required to validate our findings.