Koudriavtseva T, Sbardella E, Trento E, Bordignon V, D’Agosto G, Cordiali-Fei P.Long term follow up of peripheral lymphocyte subsets in a cohort of multiple sclerosis patients treated with natalizumab.mClin Exp Immunol. 2014 Jan. doi: 10.1111/cei.12261. [Epub ahead of print]
Natalizumab, an anti-alpha4 integrin monoclonal antibody inhibiting the adhesion of lymphocytes to the endothelium, is a widely accepted drug treatment for the relapsing-remitting multiple sclerosis (RRMS). A peripheral increase of T and B lymphocytes has already been observed as early treatment effect. This retrospective observational study was aimed to evaluate the peripheral lymphocyte subsets during a long-term treatment follow-up. We included 23 RRMS patients treated with natalizumab for at least 24 to 48 months which had pre-treatment lymphocyte evaluation. Baseline values of lymphocyte subsets and CD4/CD8 ratio did not differ significantly from the 23 matched healthy subjects. The periodic (every 3-6 months) assessment of immune cell subsets was performed by flow cytometry on peripheral blood collected before drug injection. Therapy with natalizumab was confirmed effective during the observational period. For all patients the increase in lymphocytes during natalizumab therapy compared to baseline at every assessment was significantly higher compared to that of overall white blood cells (2.1 and 1.3 fold respectively, P<0.0001). Both T cell subsets were proportionally modified and the CD4/CD8 ratio did not significantly change while B cells significantly increased compared to T and NK cells (3.2, 1.88 and 1.92 fold respectively, P<0.0001). These changes remained constant throughout the 25-48 month period of therapy. In conclusion, effective natalizumab treatment of RRMS patients was associated with the persistence of its biological effects through a stable increase of peripheral lymphocytes, mainly B cells, and an unchanged proportion of T cell subsets in long follow up.
Tysabri stops white blood cells entering the brain, so they are trapped and increase in the blood. This study shows that cells are increased in the blood during tysabri treatment.Interestingly there is a consistent and stable effect on B cells. Are these cells more important than T cells in MS. Other effective drugs target B cells.