Circulating mesenchymal stem cells, stromal derived factor (SDF)-1 and IP-10 levels increased in clinically active multiple sclerosis patients but not in clinically stable patients treated with beta interferon

Background: Mesenchymal stem cells (MSCs) have the capacity to migrate into the inflammatory regions in response to chemokines such as, IP-10 and SDF-1 alpha and function as anti-inflammatory and immunomodulatory cells. Methods: In this study we investigated the MSCs frequency in peripheral blood of Relapsing-Remitting Multiple Sclerosis (RAMS) patients in clinically active and not on disease-modifying therapy (DMT) (n = 22) and clinically stable on DMT (Interferon-beta (IFN-beta) therapy) for at least 6 months (n = 22) in comparison to sex and age-matched healthy controls (n = 25) using flow cytometry. The serum and gene expression levels of IP-10 and SDF-1a were also measured in studied groups by ELISA and Real time- PCR. Results: We obtained significant high levels of circulating CD45(-) CD34(-) CD90(+) and CD45(-) CD34(-) CD105(+) cells in clinically active patients, not on DMT and patients under IFN beta therapy compared with control group. Furthermore, a significant increase in the percentage of circulating CD45(-) CD34(-) CD105(+) CD90(+) cells was found in clinically active patients and not on DMT compared with control group. Serum analysis of IP-10 and SDF-l alpha showed a significant increase in IP10 concentration in both clinically active not on DMT (P = 0.02) and on DMT (P = 0.005) RAMS patients in comparison with controls. The expression level of SDF-1 alpha mRNA significantly increased in clinically active not on DMT (P = 0.03), while decreased in patients under IFN beta therapy (P = 0.04). The mRNA expression of IP-10 only increased in patients on DMT compared with controls (P = 0.05). Conclusion: Circulating MSCs, IP-10 and SDF-1 alpha levels, increased in RRMS patients with clinically active not on DMT and IFN-beta therapy reduced circulating MSCs and SDF-1 alpha levels.