Disease modifying therapy impacts on miRNA expression profiling in peripheral blood from Relapsing-Remitting Multiple Sclerosis patients

Multiple sclerosis (MS) is a chronic and progressive neurological disease. MS is characterized by early-stage neuroinflammation, neurodegeneration, and demyelination, with a spectrum of heterogeneous clinical manifestations in terms of disease course and response to therapy. The currently unsatisfied availability of diagnostic and prognostic biomarkers concerning disease progression and treatment response represents an important requirement for therapy individualization and drug efficacy. Specific Disease Therapies (DMTs) are available to prevent MS-related brain damage; however, the specific drug choice is still under debate and needs further characterization. Since differentially expressed miRNAs have been proposed as diagnostic tools in neurodegenerative/neuro-inflammatory diseases, such as multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's disease, we characterized the miRNA expression profiling in peripheral blood mononuclear cells (PBMC) of subjects with relapsing-remitting MS treated with high efficacy DMTs: Cladribine (CLA, n=11 patients) or Ocrelizumab (OCRE, n=14 patients). The treated patients were compared to control (CTR) untreated subjects (n=15). Blood samples were collected from patients before treatment (time t0) and 6 months post-treatment (time t1), but just once from control subjects. CLA drug tablets were administered to the selected relapsing-remitting MS patients with a dosage of 1.75 mg/kg given for 5 days. OCRE drug was administered to the other relapsing-remitting MS patients by infusion with a dosage of 300 mg, twice in two weeks. We measured miRNA expression profile, using Agilent microarray, in MS patients and control subjects without MS. Patients were treated either with Cladribine (CLA, n=11 patients) or with Ocrelizumab (OCRE, n=14 patients). Peripheral blood samples were collected from patients before treatment (time t0) and 6 months post-treatment (time t1), but just once at time t0 from control subjects.