MicroRNA-126 and 146a as potential biomarkers in systemic lupus erythematosus patients with secondary antiphospholipid syndrome

Background: MicroRNAs (miRs) are noncoding gene regulators that may have a role as diagnostic or prognostic biomarkers in systemic lupus erythematosus (SLE) and its complications. SLE is an autoimmune disease that may be associated with secondary antiphospholipid syndrome (APS). Aim of the work: To evaluate the plasma levels of both miR-146a and miR-126 as well as serum alpha interferon (α IFN) in Egyptian SLE patients with and without secondary APS and to investigate their potential role in disease pathogenesis and their utility as biomarkers for APS. Patients and methods: 88 SLE patients including 30 cases with secondary APS and 40 matched healthy individuals were enrolled in this study. SLE disease activity index (SLEDAI) was assessed. The plasma levels of miR-146a and miR-126 were determined by Realtime polymerase chain reaction (PCR) in all participants. Results: The mean age of the patients was 31.3 ± 9.6 years with disease duration 1–17 years. Plasma miR-146a was significantly lower and miR-126 significantly higher in SLE compared to controls. MiR126 was also higher in secondary APS patients compared to patients without. Serum IFN-α ws significantly higher in patients (71.2 ± 19.7 pg/ml) compared to control (43.2 ± 9.7 pg/ml) (p < 0.001). MiR-126 at a cut off of 2.66 can discriminate between SLE patients with and without secondary APS with a sensitivity of 76.67% and specificity of 81.01% ((95% CI 0.685–0.902, P < 0.001). Conclusion: Circulating miR-126 could be a potential noninvasive biomarker in SLE associated with secondary APS. Further studies are needed in view of the limited data on the expressions of microRNA in APS.