[Role of serum procalcitonin assay for diagnosis of spontaneous bacterial peritonitis in end-stage liver diseases].

OBJECTIVE

To explore the clinical value of serum procalcitonin (PCT) for predicting spontaneous bacterial peritonitis (SBP) in end-stage liver diseases.

METHODS

The clinical data of 362 ascitic inpatients with end-stage liver diseases who had underwent serum PCT assay in our department from March 2011 to June 2013 were analyzed retrospectively. These patients were then divided into SBP group (n=178) and non-SBP group (n=184). The dynamic changes of the PCT values upon admission and after antibiotic treatment were compared. The receiver operating characteristic curve was drawn to identify the optimal cut-off value of serum PCT in diagnosing SBP.

RESULTS

The positive rate of bacteria culture in ascites was only 4.6% (4/87) in SBP group. The median value of serum PCT was 0.73 and 0.15 ng/ml in SBP group and non-SBP group (Z=-11.9, U=0.000), respectively, before antibiotic treatment. In the SBP group, the median value of serum PCT was 1.73 ng/ml in 13 patients with positive culture findings, which was higher than the overall median value in SBP group. Among patients who were responsive to the antibiotic therapy, the median values of serum PCT were 0.40(n=46), 0.32(n=19), and 0.33 ng/ml(n=25), respectively, 3, 5, and 7 days after the effective antibiotics treatment, which were significantly lower than the pre-treatment levels [0.86(Z=-5.91, U=0.000), 0.72(Z=-3.10, U=0.002), and 0.79 ng/ml(Z=-4.37, U=0.000), respectively]. ROC analysis showed that a serum PCT value of more than 0.462 ng/ml had a sensitivity of 83.7% and a specificity of 94.9%(AUC:0.95, 95%CI:0.93-0.97, P=0.00) in diagnosing SBP in patients with end-stage liver diseases.

CONCLUSIONS

Ascitic fluid positive rate is low in SBP patients. Serum PCT is a sensitive and specific marker for predicting peritoneal bacteria infection in end-stage liver disease patients with ascites. Higher serum PCT can be expected in these patients with heavier infections, it can also be used to evaluate the effectiveness of anti-bacteria therapies.