Natalizumab influences CD4⁺ T cells from MS patients immediately after the very first infusion.

<p>Pre- and post-natalizumab blood samples were taken from 9 patients with RRMS. (A-C) PBMC were cultivated with plastic-coated anti-CD3/28 for 24 h. (A) Cells were stained for surface expression of CD4 and CD49d before and after <i>in vitro</i> restimulation. (B, C) Cells were stained for intracellular IL-2, IL-17 and IFN-γ concomitantly with staining for surface CD4, and analyzed by FACS. (D) as in A-C, but <i>in vitro</i> restimulation for 48 h. Secretion of interleukins was evaluated by cytometric bead arrays. A two-tailed Kruskal-Wallis test followed by Dunn’s posttest was used in (A) for statistical analysis (no matched pairs test possible due to one missing value). Two-tailed Wilcoxon matched-pairs signed rank tests were performed for statistical analysis in (B) and (D). Spearman correlation coefficients were calculated in (C).