A long-term follow-up study on biochemical and clinical biomarkers of response to interferon beta-1b treatment in relapsing-remitting multiple sclerosis

CD4+ and CD25+ T-cell response to short-time interferon-beta therapy on IL10, IL23A and FOXP3 genes in multiple sclerosis patients

AIM OF THE STUDY

Interferon-beta (IFN-β), multiple sclerosis (MS) drug for years, does not have therapeutic effects on each patient. Yet, a considerable portion has experienced no therapeutic response to IFN-β. Therefore, it is necessary to determine disease-specific biomarkers that affect drug response. Here, we aimed to determine the effects of interleukin 10 (IL10) and 23 (IL23A), as well as forkhead box P3 (FOXP3) genes on MS after IFN-β therapy.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) of 42 MS patients were isolated to obtain CD4+ and CD25+ T cells. Both cell types were characterised by flow cytometry. To determine optimum drug concentration of IFN-β, cytotoxicity assays were assessed on each cell type for 4, 16, 24 and 48 hours respectively. Then, cells were cultured in the presence of 500 IU/mL of IFN-β. cDNA synthesis was performed after mRNA extraction. RT-PCR was performed to measure gene expressions of IL10, IL23A and FOXP3. Results were evaluated statistically.

RESULTS

It was found that the cytotoxic effect of IFN-β was more efficient as the exposure time was expanded regardless of drug concentration. Moreover, CD25+ T lymphocytes were more resistant to IFN-β. IL23A was down-regulated, whereas FOXP3 was up-regulated at 48 hours in CD4+ T cells. For CD25+ T cells, the graded increase in FOXP3 was obtained while IL10 expression was gradually decreased throughout the drug intake.

CONCLUSION

Although a considerable change in expression was obtained, the long-term IFN-β effect on both genes and cells should be determined by follow-up at least a year.