CD27 and Sepsis: The proportion of B cells positive for PD-1 and the corresponding MFI were significantly greater in patients with sepsis than in controls (26.5% vs 8.8%, p = 0.0002; 483 vs 348, p = 0.0003) (Additional file 4: Table S3; Fig. 1): this was true of both CD27+ and CD27- subsets (Additional file 5: Table S4; Additional file 6: Figure S2; Additional file 7: Figure S3).