T helper type cytokines in sepsis: time-shared variance and correlation with organ dysfunction and hospital mortality.

Objective: We evaluated the kinetics of cytokines belonging to the T helper1 (Th1), Th2, and Th17 profiles in septic patients, and their correlations with organ dysfunction and hospital mortality.

Methods: This was a prospective observational study in a cohort of septic patients admitted to the intensive care units (ICU) of three Brazilian general hospitals. A total of 104 septic patients and 53 health volunteers (controls) were included. Plasma samples were collected within the first 48h of organ dysfunction or septic shock (0D), after seven (D7) and 14 days (D14) of follow-up. The following cytokines were measured by flow cytometry: Interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-10, IL-12/23p40, IL-17, IL-21, tumor necrosis factor-α (TNF-α), granulocyte-macrophage colony stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF).

Results: IL-6, IL-8, G-CSF and IL-10 concentrations were higher in septic patients than in controls (p<0.001), while IL-12/23p40 presented higher levels in the controls (p=0.003). IL-6, IL-8 and IL-17 correlated with Sequential [Sepsis-related] Organ Failure Assessment (SOFA) D0, D1 and D3 (except for IL-6 at D0). IL-8 was associated with renal and cardiovascular dysfunction. In a mixed model analysis, IL-10 estimated means were lower in survivors than in deceased (p=0.014), while IL-21 had an estimated mean of 195.8pg/mL for survivors and 98.5 for deceased (p=0.03). Cytokines were grouped in four factors according to their kinetics over the three dosages (D0, D7, D14). Group 1 encompassed IL-6, IL-8, IL-10, IL-1β, and G-CSF while Group 3 encompassed IL-17 and IL-12/23p40. Both correlated with SOFA (D0) (p=0.039 and p=0.003, respectively). IL-21 (Group 4) was higher in those who survived. IL-2, TNF-α and GM-CSF (Group 2) showed no correlation with outcomes.

Conclusion: Inflammatory and anti-inflammatory cytokines shared co-variance in septic patients and were related to organ dysfunctions and hospital mortality.