Coincidence of pro- and anti-inflammatory responses in the early phase of severe sepsis: Longitudinal study of mononuclear histocompatibility leukocyte antigen-DR expression, procalcitonin, C-reactive protein, and changes in T-cell subsets in septic and postoperative patients.

OBJECTIVE: To determine the time course of histocompatibility leukocyte antigen (HLA)-DR expression in peripheral blood mononuclear cells and their relationship to markers of inflammation, organ function, and outcome during severe sepsis.
DESIGN: Prospective, longitudinal study.
SETTING: University hospital intensive care unit. PATIENTS: Twenty-three postoperative patients with severe sepsis and 26 patients with uneventful postoperative course as well as 24 healthy, age-matched subjects.
INTERVENTIONS: Serum procalcitonin was determined by using an immunochemiluminescence assay, and C-reactive protein and leukocyte antigens were determined by using flow cytometry over 14 days in parallel with clinical data collection.
MEASUREMENTS AND MAIN RESULTS: Despite a relative lymphopenia, absolute lymphocyte counts and CD4+/CD8+ T-cell ratio in septic patients were significantly elevated above normal. Particularly, CD4+ and CD8+ T-cell counts in nonsurvivors of sepsis were approximately twice as high as those of survivors. Significantly decreased monocytic HLA-DR expression was observed in both survivors and nonsurvivors at the onset of severe sepsis. Percentages of HLA-DR+ lymphocytes, however, were significantly increased during sepsis, especially in nonsurvivors. Whereas survivors of sepsis showed a continuous recovery of monocytic HLA-DR expression to >or=70% within 10 days, nonsurvivors were characterized by a second decrease in monocytic HLA-DR expression after day 7 or a permanent suppression (<40%). Peak of systemic inflammatory reaction, documented by maximum serum concentrations of procalcitonin and C-reactive protein, coincided with the nadir of monocytic HLA-DR expression. Moreover, procalcitonin and C-reactive protein as well as scores on the Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment were inversely correlated with the monocytic HLA-DR expression.
CONCLUSIONS: Decreases in monocytic HLA-DR expression occurred simultaneously with signs of hyperinflammation as early as the onset of severe sepsis and usually developed in opposite directions than inflammatory markers and sepsis severity scores.