RESUMO
Background: MicroRNAs [miRNAs] are small non-coding RNAs, whose role in regulating diverse immune functions, suggests they might play a role as biomarkers for immune medi-ated disorders. Studies showed that miRNA-146a [miR-146a] expression is increased by proinflammatory cytokines and is an important modulator of differentiation and function of cells of innate and adaptive immunity
Aim of the work: The current study aimed to evaluate the expression of miR-146a as a potential biomarker for diagnosis of rheumatoid arthritis [RA] and to explore its association with disease activity
Subjects and methods: The study enrolled 50 Egyptian subjects divided into a patient group, which comprised 25 RA patients, and a control group which comprised 25 healthy individuals
The disease activity for the patients' group was determined by simplified disease activity index. Relative quantification of miR-146a expression in whole blood was determined using reverse tran-scriptase quantitative real time polymerase chain reaction
Results: There were highly significant statistical differences between patients and healthy controls as regards miR-146a relative expression, erythrocyte sedimentation rate [ESR] and anti-cyclic citrullinated peptide [anti-CCP] [p < 0.001]. Highly significant statistical differences [p < 0.001] were also found between different patients' subgroups as regards miR-146a relative expression and ESR. rm'R-146a levels correlated positively with those of ESR, C-reactive protein and anti-CCP [p < 0.001]
miR-146a illustrated best performance in diagnosing RA, showing the highest sensitivity and specificity [96% and 100%, respectively] [AUC: 0.992 at a cut off value of >/=2.16] compared to anti-CCP [sensitivity: 68%, specificity: 100% and AUC: 0.87 at a cut off value of >/= 22 U/ml] and RF [sensitivity: 56%, specificity: 80% and AUC: 0.992 at a cut off value of >/=13 U/ml]
Conclusion: This study demonstrated that miR-146a expression was highly significantly elevated in whole blood of patients with RA. Its diagnostic performance was better than anti-CCP and RF and its level of expression correlates with disease activity