Natalizumab alters the TCR repertoire after one year of treatment in four MS patients

Background Natalizumab is an approved drug used in relapsing and aggressive Multiple Sclerosis (MS). This is a monoclonal anti-integrin antibody that decreases the transmigration of immune cells through the blood-brain-barrier in animal models of MS. In human, the number of T cells in the CSF is dramatically decreased while the number of circulating lymphocytes usually increases. We hypothesized that in patients treated with natalizumab, the infiltration of T cells in the brain parenchyma decreases. These cells may accumulate in the blood of the patients and thus alter the T cell repertoire.