Heterogeneity among septic shock patients in a set of immunoregulatory markers

Immune activation is a regular feature of sepsis, but the incidence and nature of the ensuing inflammation-resolving and immunosuppressive component is less well understood. In this study, we compared immunoregulatory markers on blood leukocytes from patients with Gram-negative or Gram-positive sepsis or septic shock, and compared this to blood from patients with severe virosis or healthy controls. To this end, blood from 32 patients with sepsis, including ten cases with shock, and 12 patients with severe virosis were analysed by flow cytometry for the expression levels of monocyte HLA-DR, CD11c, CD14 and CD40, and for frequencies of CD163⁺-suppressive monocytes, HLA-DR⁺ or CD40⁺-activated T cells and Tregs. Plasma cytokine levels were analysed as a functional measurement. Signs of immunosuppression dominated in the septic shock and Gram-positive sepsis groups, whereas monocyte activation was common in Gram-negative sepsis patients without shock. However, the main finding was the large inter-individual variation of immune activation and immunosuppression, with no correlation to prognosis among the shock patients. The pronounced inter-individual variation in the analysed monocyte and lymphocyte markers forms a strong argument that, when immunomodulatory treatment is considered in a sepsis patient, it should be personalised and guided by a detailed immune status assessment.