Effects of Interferon Beta, Cyclophosphamide and Azathioprine on Cytokine Profile in Patients with Multiple Sclerosis

We assessed the in vitro effects of interferon beta-1b (IFNβ-1b), cyclophosphamide (CY), and azathioprine (AZA) alone and of the combination of IFNβ-1b with CY or AZA on the production of Th1 and Th2 cytokines in 10 patients with multiple sclerosis. Cytokine levels were determined at baseline and after stimulation with IFNβ-1b, CY, and AZA alone or with the combination of IFNβ-1b with CY or AZA. The combination of IFNβ-1b with CY resulted in a statistically significant decrease in the production of interleukin-2 (IL-2) (P=0.003) and tumor necrosis factor alfa (TNF-α) (P=0.03). An additive effect on the production of interferon gamma (IFN-γ) (P=0.2) and interleukin-10 (IL-10) (P=0.6), and a positive interaction on the production of interleukin-4 (IL-4) (P=0.08) were observed although the findings were not statistically significant. The combination of IFNβ-1b with AZA resulted in a significant negative effect on the production of IL-2 (P=0.006), whereas TNF-α (P=0.02), IFN-γ (P=0.03), IL-4 (P=0.2), and IL-10 (P=0.3) were not statistically impacted. Our data show that CY was able to improve the effects of IFNβ-1b on the ratio of Th1/Th2 cytokines.