Procalcitonin as a marker of severity in septic shock

Background/aims. Procalcitonin (PCT) was shown to be related to the severit y of bacterial infection and is recommended as a new parameter of inflammat ion and infection. To evaluate the prognostic value in septic shock, PCT le vels were repeatedly determined and compared with tumour necrosis factor-al pha (TNF-alpha)- and interleukin (IL)-6 bioactivity as well as with C-react ive protein (CRP) serum levels. Patients: Twenty-four surgical patients wit h septic shock were included. Eight patients died within the study period o f 14 days. Methods: Serum levels of TNF(WEHI 164) and IL-G (B13-29 subclone 9) bioactivity, CRP and PCT were determined on days 1, 3, 5, 7, 10 and 14 following diagnosis of septic shock. Results. Survivors and non-survivors w ere comparable in terms of age and severity of sepsis characterized by the APACHE II score and multiple-organ-failure score. Predominant causes of sep sis were peritonitis and necrotiszing pancreatitis. TNF levels increased in non-survivors with no significant difference to survivors. IL-6 bioactivit y was increased on day 1 (P = 0.06) and remained elevated in non-survivors, in whom it was significant on day 7 (P<0.05). CRP was constantly elevated with no difference between the groups. In nonsurvivors PCT remained increas ed, while the course of survivors was characterized by decreased values whi ch were significantly lower (P<0.05) at every time point compared with thos e patients who died. A significant correlation could be found on day 1 (P<0 .05) and at the end of the observation period (P<0.01) when comparing PCT l evels with the multiple-organ-failure score. Conclusions: PCT seems to be a more reliable prognostic parameter in septic shock than IL-6, while TNF an d CRP did not show any difference between survivors and non-survivors. Thes e data indicate that PCT may represent a valuable parameter not only in the diagnosis of sepsis but also in the clinical course of the disease.