Acute-phase proteins as indicators of bacterial infection in patients with cirrhosis

Background: Cirrhosis is associated with elevated levels of acute-phase proteins (APP), irrespective of the presence of infection. This condition limits the clinical application of APP determination in cirrhotic patients with bacterial infections. Aims: To weigh the diagnostic value of several APP in cirrhotics with or without bacterial infection, and to correlate them with the clinical outcome. Methods: We investigated 88 consecutive cirrhotic patients (67 males, 21 females; range 28–85 years) with mean age (SD) 58.9 (13.8) on admission, according to a standard protocol for infection. We measured the following APP: C-reactive protein (CRP), fibrinogen (FIB), haptoglobin (Hpt), ferritin (Fer), β2-microglobulin (β2-mg), C3, C4 and C1 inhibitor. Results: From the 88 patients, 19 (21.6%) had documented infection at the entry based on clinical, radiological and microbiological data. This group of patients did not differ in basic demographics from those without infection. CRP [17.5 (20.7) vs 77.1 (43.9), P55.8 mg/L has high sensitivity (79%) and specificity (96%), with the best diagnostic accuracy (92%).