MicroRNA146a gene polymorphism in patients with rheumatoid arthritis and the relevant value with disease activity and extra-articular manifestations

Abstract

Aim of the workTo analyze the relationship between miRNA-146a rs2910164 and rheumatoid arthritis (RA) susceptibility and clarifying its association with disease activity and extra-articular involvement. Patients and methodsThe study enrolled 50 RA patients and 40 controls. DNA extraction from whole blood was done. Genotyping was performed by real-time polymerase chain reaction. The selected single nucleotide polymorphism was rs2910164 in the miRNA-146a gene. Genotyping was performed on genomic DNA samples by allelic discrimination assay. Disease activity score (DAS28) and health assessment questionnaire-disability index (HAQ-DI) were assessed. ResultsThe mean age of patients was 44.8 ± 9.9 years while age at onset was 37.2 ± 9.8 years. Female:male was 5.3 vs 1. Females had significantly higher DAS28, visual analogue scale and rheumatoid factor (RF) than males (p = 0.04, p = 0.009, p = 0.03). The frequency of GC genotype was more in both males and females (62.5 vs 47.6%). GC genotype and G allele were the most frequent in patients. No significant difference in the frequency distribution of genotypes and alleles was observed between patients and controls. There was a significant difference in the number of swollen joints (p = 0.04) and sicca symptoms (p = 0.01) being higher in those with CC genotype with a tendency of increased DAS28, HAQ-DI, deformities and rheumatoid nodules with CC genotype and interstitial pulmonary fibrosis and RF with GG genotype. ConclusionsCC genotype was associated with sicca symptoms and swollen joints, deformities, disease activity and functional disability. miRNA-146a may be a potential biomarker for extra-articular manifestations of RA that need more attention and warrant aggressive therapy.