OBJECTIVE: To evaluate the recently discovered long pentraxin PTX3 in plasma of 
critically ill patients and to compare it with the classic short pentraxin 
C-reactive protein and with other indicators of inflammation.
DESIGN: A cohort study on plasma samples.
SETTING: Medical intensive care unit (ICU) of the University Hospital of Basel.
PATIENTS: A total of 101 consecutive critically ill patients admitted to the 
medical ICU.
INTERVENTIONS: Venous blood samples were routinely obtained at entry, on day 2, 
and at discharge or before death.
MEASUREMENTS AND MAIN RESULTS: Plasma samples were obtained from 101 consecutive 
critically ill patients admitted to the ICU with systemic inflammatory response 
syndrome, sepsis, or septic shock. PTX3 plasma levels were measured by 
enzyme-linked immunosorbent assay. PTX3 was elevated in critically ill patients, 
with a gradient from systemic inflammatory response syndrome to septic shock. 
PTX3 levels correlated with clinical scores reflecting severity of disease 
(e.g., Acute Physiology and Chronic Health Evaluation II: p =.00097). In 
addition, high levels of PTX3 were associated with unfavorable outcome.
CONCLUSIONS: The long pentraxin PTX3 is elevated in critically ill patients and 
correlates with severity of disease and infection. Compared with the short 
pentraxin C-reactive protein, PTX3 may be a more direct indicator of tissue 
involvement by inflammatory and infectious processes.