Effect of teriflunomide on QuantiFERON-TB Gold results.

Multiple sclerosis is a chronic inflammatory disease of the central nervous system characterized by damage to myelin and axons, over time leading to progressive neuronal degeneration and microglial activation. There is still no curative treatment, but during the last 20 years eight different therapies have become available including interferon beta, glatiramer acetate, teriflunomide, dimethyl fumarate, natalizumab, fingolimod, alemtuzumab, mitoxantrone and teriflunomide. Teriflunomide is an immunomodulatory drug that exerts an inhibitory effect on T cell activation in central nervous system of the patients with multiple sclerosis. We determined whether teriflunomide affect the production of interferon-gamma, interleukin-2 and tumor-necrosis-factor-α in the QuantiFERON-TB in-Tube-assay. Blood from 24 adults with latent tuberculosis infection was added to one standard set of QuantiFERON tubes and one further set containing teriflunomide. Teriflunomide resulted in a change in QuantiFERON results from positive to negative in four patients with a marked reduction in interferon-γ. Our data indicated that results from QuantiFERON in patients on teriflunomide therapy should be interpreted with caution.