Acute phase proteins in the diagnosis and prediction of cirrhosis associated bacterial infections

Liver Int. 2012 Apr;32(4):603-11. doi: 10.1111/j.1478-3231.2011.02689.x. Epub 2011 Dec 6.


Background: Bacterial infections are common cause of morbidity and mortality in patients with cirrhosis. The early diagnosis of these infections is rather difficult.

Aims: To assess the accuracy of acute phase proteins in the identification of bacterial infections.

Methods: Concentration of C-reactive protein (CRP), procalcitonin (PCT), lipopolysaccharide-binding protein (LBP), sCD14 and antimicrobial antibodies were measured in serum of 368 well-characterized patients with cirrhosis of whom 139 had documented infection. Clinical data was gathered by reviewing the patients' medical charts.

Results: Serum levels of CRP, PCT and LBP were significantly higher in patients with clinically overt infections. Among the markers, CRP - using a 10 mg/L cut-off value- proved to be the most accurate in identifying patients with infection (AUC: 0.93). The accuracy of CRP, however, decreased in advanced stage of the disease, most probably because of the significantly elevated CRP levels in non-infected patients. Combination of CRP and PCT increased the sensitivity and negative predictive value, compared with CRP on its own, by 10 and 5% respectively. During a 3-month follow-up period in patients without overt infections, Kaplan-Meier and proportional Cox-regression analyses showed that a CRP value of >10 mg/L (P = 0.035) was independently associated with a shorter duration to progress to clinically significant bacterial infections. There was no correlation between acute phase protein levels and antimicrobial seroreactivity.

Conclusions: C-reactive protein on its own is a sensitive screening test for the presence of bacterial infections in cirrhosis and is also a useful marker to predict the likelihood of clinically significant bacterial infections in patients without overt infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Proteins* / analysis
  • Adult
  • Aged
  • Bacterial Infections / complications
  • Bacterial Infections / diagnosis*
  • Bacterial Infections / microbiology
  • C-Reactive Protein / analysis
  • Calcitonin / blood
  • Calcitonin Gene-Related Peptide
  • Carrier Proteins / blood
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Likelihood Functions
  • Liver Cirrhosis / complications*
  • Male
  • Membrane Glycoproteins / blood
  • Middle Aged
  • Proportional Hazards Models
  • Protein Precursors / blood
  • ROC Curve
  • Regression Analysis


  • Acute-Phase Proteins
  • CALCA protein, human
  • Carrier Proteins
  • Membrane Glycoproteins
  • Protein Precursors
  • lipopolysaccharide-binding protein
  • Calcitonin
  • C-Reactive Protein
  • Calcitonin Gene-Related Peptide