Roles of serum procalcitonin and C-reactive protein in the diagnosis of nonneutrocytic ascitic spontaneous bacterial peritonitis in liver cirrhosis

Objective To investigate the diagnostic value of serum procalcitonin (PCT) and C-reactive protein (CRP) in nonneutrocytic ascitic spontaneous bacterial peritonitis (NASBP). Methods From January 2012 to January 2015, patients with liver cirrhosis and ascites were restropectively enrolled.Patients were divided into NASBP group and non-infective ascites group.The receiver operating characteristics curve (ROC) was used for assessing diagnostic accuracy of serum PCT and CRP.Patients with conventional SBP were set as controls. Data between two groups were compared using t test, Rank sum test, χ2 test or Fisher exact test. The areas under ROC curve or Youden indeces were compared using Z test. Results A total of 30 patients were collected in NASBP group, 51 patients in non-infective ascites group and 33 patients in conventional SBP group. There were no statistically significant differences in PCT and CRP levels between NASBP group and conventional SBP group [0.70(0.25～2.45) μg/L，(21.85±16.46) mg/L；0.90(0.33～3.56) μg/L，(31.78±26.74) mg/L] both P>0.05, and were both significantly higher than those of non-infective ascites group (0.20(0.07~0.40) μg/L, Z=-3.38, t=4.64; (7.19±7.04) mg/L, Z=-3.89, t=-5.17, both P 0.05). The specificities were 76.5%, 88.2%, 94.1% and 74.5%, respectively. There was no statistically significant difference in PCT and CRP between combination in parallel and in series, while the differences in the other pairwise comparisons of combinations were statistically significant (Fisher exact test, P 0.05). Conclusions All of serum PCT, CRP and the combination of them have good diagnostic value in NASBP with their own advantages which should be selected based clinical needs. Key words: Procalcitonin; C-reactive protein; Peritonitis; Diagnosis