In Critically Ill Patients, Serum Procalcitonin Is More Useful in Differentiating between Sepsis and SIRS than CRP, Il-6, or LBP

Abstract

We studied the usefulness of serum procalcitonin (PCT), interleukin-6 (IL-6), lipopolysaccharide binding protein (LBP) levels and C-reactive protein (CRP) levels, in differentiating between systemic inflammatory response syndrome (SIRS) and sepsis in critically ill patients. Methods. In this single centre prospective observational study we included all consecutive patients admitted with SIRS or sepsis to the ICU. Blood samples for measuring CRP, PCT, IL-6 and LBP were taken every day until ICU discharge. Results. A total of 76 patients were included, 32 with sepsis and 44 with SIRS. Patients with sepsis were sicker on admission and had a higher mortality. CRP, PCT, IL-6 and LBP levels were significantly higher in patients with sepsis as compared to SIRS. With PCT levels in the first 24 hours after ICU admission <2 ng/mL, sepsis was virtually excluded (negative predictive value 97%). With PCT >10 ng/mL, sepsis with bacterial infection was very likely (positive predictive value 88%). PCT was best at discriminating between SIRS and sepsis with the highest area under the ROC curve (0.95, 95% CI 0.90–0.99). Discussion. This study showed that PCT is more useful than LBP, CRP and IL-6 in differentiating sepsis from SIRS.

Wie verlässlich ist die Bestimmung von Procalcitonin als Entzündungsmarker auf Intensivstation?/How reliable is procalcitonin as an inflammatory marker?

“…Trotz dieser Einschr ä nkung zeigen viele Studien, dass Spezifi t ä t und Sensitivit ä t der PCT-Spiegel f ü r die Diagnose einer bakteriellen Infektion h ö her als die anderer Parameter wie zum Beispiel den immer noch am h ä ufi gsten genutzten CRP-Spiegeln oder den Leukozytenzahlen sind [24] . Auch konnte in neueren Studien gezeigt werden, dass PCT-Spiegel besser in der Lage sind zwischen SIRS und Sepsis zu unterschieden als CRP, IL-6 und LBP-Plasmaspiegel [10,25] . Insgesamt weisen die vorliegenden Daten darauf hin dass ein Anstieg der PCT-Spiegel bei einem Risikopatienten auf Intensivstation als Verdacht auf eine zugrunde liegende oder beginnende Infektion gewertet werden muss und auf jeden Fall weiter abgekl ä rt werden muss.…”

“…Die Spezifi t ä t und der positive pr ä diktive Wert zur Erkennung einer Infektion liegen in den meisten Untersuchungen bei > 80 % und damit ü ber denen anderer biochemischer Marker [10,11,50,51] . Allerdings ist zu ber ü cksichtigen, dass auch andere Erkrankungen zum Anstieg der zirkulierenden PCT-Spiegel f ü hren k ö nnen.…”

Procalcitonin: a valuable markerfor assessment of the success of antimicrobial therapy for severe sepsis An analysis using routine clinical data

“…In particular, extensive clinical evidence indicates that PCT is a biomarker for both follow-up and evaluation of the effectiveness of antibiotic therapy for severe respiratory infections and sepsis; in all relevant guidelines, the use of PCT in this context is categorized as evidence class 2B or 2C [3,4]. For example, PCT levels differentiate more effectively between sepsis and systemic inflammatory response syndrome (SIRS) than those of IL-6, IL-8, or CRP [5,6]. A meta-analysis of several clinical studies of various infections demonstrated that PCTguided antibiotic therapy reduced both therapy duration and the length of stay in intensive care [7].…”

Use of a Combination Biomarker Algorithm To Identify Medical Intensive Care Unit Patients with Suspected Sepsis at Very Low Likelihood of Bacterial Infection

“…Several studies have evaluated the diagnostic utility of various biomarkers, including ferritin, haptoglobin, interleukin 6, C-reactive protein (CRP), and procalcitonin (PCT), for suspected sepsis in the ICU patient population (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). PCT has been the most-well-studied biomarker and has demonstrated the most promising results to date in the diagnosis of bacterial infection in a number of settings (16)(17)(18)(19)(20)(21).…”

“…However, recent meta-analyses have suggested that PCT alone may be insufficient to accurately differentiate bacterial from nonbacterial sepsis or other causes of SIRS (22)(23)(24). Similarly, previous studies assessing the use of PCT alone or in comparison to other biomarkers for the diagnosis of sepsis have had variable performance characteristics (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), likely due to differences in patient populations, the type of assay performed, the timing of sample testing, the selection of cutoff values, and the selection of the gold standard for determining sepsis.…”