Objectives
To investigate the relationship between endogenous serum concentrations of granulocyte colony stimulating factor (G-CSF) and phagocytotic activity of granulocytes during septic shock in postoperative/post-traumatic patients.
Methods
Over a 6 month period 35 patients with proven infection and severe sepsis or septic shock for at least 3 days' duration were monitored on a daily basis during their stay in the intensive care unit (ICU) until discharge from the ICU or death. In 19 out of these 35 patients one or more peaks in G-CSF serum concentrations occurred. Eleven of these 19 patients survived, eight patients died. A longitudinal analysis of G-CSF serum concentrations, phagocytotic activity of granulocytes and surface expression of monomeric Fc receptor type I (CD64, FcγRI) on granulocytes was performed by ELISA technique (R&D Systems, Minneapolis, MN, USA) and flow cytometry (Phagotest™; Orpegen, Heidelberg, Germany) and CD64 (clone 22; Immunotech, Krefeld, Germany), respectively on a daily basis.
Results
A G-CSF peak was defined as an increase of at least 30% from one day to the other, followed by a decrease of at least 15% on the next day. The following results are expressed as median (min – max) values. In seven episodes there was a parallel course of the G-CSF peak and phagocytosis with an increase in phagocytosis by 37% (6–50%). In 11 episodes, phagocytosis continuously increased and remained on a higher level after the increase of 10% (1–164%) from day 1 up to day 2. In 10 episodes, there was a decrease by 40% (17–76%) at the day of the G-CSF peak, followed by an increase by 58% (6–322%) on the next day. In 12 episodes, there was no increase (n = 4) or even a decrease (n = 8) by 24% (3–46%) over all days.
Conclusions
A peak in G-CSF serum concentration was followed by a continuous increase in phagocytosis at the same day in 7, and a delayed increase in 21 out of 40 episodes, but no increase or even an decrease in 12 out of 40 episodes. Thus, phagocytotic activity is increased when G-CSF peaks endogenously, in most patients with severe sepsis or septic shock.