The Effect of Plasma Exchange on the Expression of FOXP3 and RORC2 in Relapsed Multiple Sclerosis Patients

Background: Lack of sufficient information on the mechanism of plasma exchange (PE) therapy in multiple sclerosis (MS), has limited this treatment to individual patients with severe relapses who have been refractory to other treatments. This is while PE is used very successfully as a first-line standard treatment in many other neuro-immune disorders. Recent data suggest that Treg/Th17 counterbalance may indicate the boundaries between promotion and regulation of inflammatory responses in MS and Treg/Th17 ratio may be useful as a marker for monitoring the efficiency of MS therapies. Objective: To evaluate the effect of PE on the frequency and ratio of Treg/Th17 cells through concomitant measurement of the expression levels of Treg and Th17 lineage specific transcription factors, FOXP3 and RORC2, respectively. Methods: Peripheral blood mononuclear cells of 8 relapsed MS patients were obtained before and after a complete course of PE therapy and the FOXP3 and RORC2 mRNA levels were assayed using real-time PCR approach. Results: No significant change in the expression levels of individual transcription factors existed, but a significant increase in FOXP3/RORC2 ratio (p=0.036) was observed. Conclusions: Our results suggest that PE therapy influences Treg/Th17 ratio and this maybe a mechanism by which this procedure exerts its improving effects in MS disease.