Figure 1. Treatment with IVIg reduces NK cell frequency, but not the frequency of T cells and B cells.

Flow cytometry analysis of PBMCs from patients with CIDP (n = 14) before treatment initiation and 24 hours after IVIg treatment. (A) Representative gating strategy to define NK cells. Lymphocytes were identified based on the size and granularity of cells. To exclude NKT cells, CD56 and CD3 costaining was performed. Gated on CD56⁺/CD3⁻ cells, subpopulations of CD16⁺/CD56^dim and CD16⁻/CD56^bright NK cells were determined. (B) Changes in NK cells gated on lymphocytes in individual IVIg-naive patients and 24 hours after IVIg infusion. (C) Proportion of CD56^bright and CD56^dim NK cell subpopulations within lymphocytes. Depicted is mean ± SEM of the analyzed patients. (D) Changes in CD56^bright subpopulation gated on NK cells in individual IVIg-naive patients and 24 hours after IVIg infusion. (E) Changes in frequencies of T cells and B cells gated on lymphocytes in individual IVIg-naive patients and 24 hours after IVIg infusion. (F) Depicted are changes in the ratio of lymphocytes and monocytes within the leukocyte population in individual IVIg-naive patients and 24 hours after IVIg infusion (asterisks indicate significance: ***p < 0.001; nonparametric distribution; Wilcoxon rank test for paired samples). CIDP = chronic inflammatory demyelinating neuropathy; IVIg = IV immunoglobulin; NK = natural killer; PBMC = peripheral blood mononuclear cell.