Changes in receptor expression on CD4 and CD8 T cells over the course of acute sepsis. Peripheral blood was collected at enrollment and again seven days later from patients with severe sepsis and from normal controls and analyzed by flow cytometry for the indicated markers on CD4- and CD8-positive T cells. The lines connect values at enrollment and the end of the study from an individual subject. Percentages and MESF values were calculated as described in the methods. P values were calculated by 2-tailed, non-parametric Wilcoxin matched pairs test. MESF, molecules of equivalent soluble fluorochrome.