Potential Value of miR-23a for Discriminating Neuromyelitis Optica Spectrum Disorder from Multiple Sclerosis

Background: Until now, no laboratory test or test set can guarantee the diagnosis of multiple sclerosis (MS) at early disease stages, and the disease symptoms may interfere with many other disease conditions. Analyzing the expression of circulating miRNAs may provide a useful approach for early and differential MS diagnosis. The main objective is assessment of the potential of serum miR-23a, miR-155, and miR-572 to differentiate between MS and other neuroinflammatory diseases. Methods: Serum miRNAs were obtained from 37 MS patients and 25 healthy age-matched controls, along with patients with neuromyelitis optica spectrum disorder (NMOSD) [n = 13] and neuropsychiatric systemic lupus erythematosus (NPSLE) [n = 10]. miRNA expression levels were analyzed using real-time polymerase chain reaction (PCR) and pairwise comparisons were made to reveal the diagnostic/distinguishing potential of the analyzed miRNAs. Results: In the study cohort, the three investigated miRNAs failed to display significant dysregulation in MS patients. However, they could significantly discriminate patients with NMOSD and NPSLE [median (IQR): 8.1 (6.1–9.2) and 8.8 (7.9–9.7) for miR-23a, 7.5 (5.3–8.3) and 8.0 (7.5–9.5) for miR-155 and 6.9 (5.0–8.8) and 6.4 (5.3–8.8) for miR-572 in NMOSD and NPSLE, respectively] from healthy subjects [median (IQR): 3.4 (1.5–4.3), 3.1 (1.1–5.6) and 3.5 (1.7–5.6) for miR-23a, miR-155 and miR-572, respectively], with area under the curve (AUC) ≤0.8. Remarkably, miR-23a has been emerging as a prospective biomarker for differentiation of MS from NMOSD as well as NPSLE (AUC<0.9). The miRNA combined use contributed to enhanced diagnostic and discriminatory performance in the study groups. Conclusion: Certain miRNA expression levels would contribute to discriminating MS from other neuroinflammatory diseases.