Fig. 1

CD19+ B cell proportions and gating strategy. Comparison of the median CD19+ B cell proportions in the PBMCs of nonagenarian individuals and young individuals was analyzed with gating directly to CD19 from non-debris gate (blue) and with first gating out the CD3+, CD14+ and CD56+ (red). Error bars represent 95% confidence interval. a Median B cell proportions in nonagenarian males and young males. Significance for the age difference was p = 0.02 for the non-debris CD19+ cells and p = 0.011 for the dump-negative CD19+ cells. b Median B cell proportions in nonagenarian females and young females. Significance for the age difference was p < 0.001 for the non-debris CD19+ cells and p < 0.001 for the dump-negative CD19 + cells. c Gating strategy for CD19+ B cells. The percentage of CD19+ cells was determined after exclusion of debris (non-debris gate) and cell doublets (singlets gate), or after additionally gating out cells that express T cell, NK cell and monocyte lineage markers CD3, CD56 and CD14, respectively (“dump channel”, dump negative gate)