title: Measurement of serum procalcitonin levels for the early diagnosis of spontaneous bacterial peritonitis in patients with decompensated liver cirrhosis.
abstract: BACKGROUND
  It is difficult to diagnose spontaneous bacterial peritonitis (SBP) early in decompensated liver cirrhotic ascites patients (DCPs). The aim of the study was to measure serum procalcitonin (PCT) levels and peripheral blood leukocyte/platelet (WBC/PLT) ratios to obtain an early diagnostic indication of SBP in DCPs.
  
  
  METHODS
  Our cohort of 129 patients included 112 DCPs (94 of whom had infections) and 17 cases with compensated cirrhosis as controls. Bacterial cultures, ascitic fluid (AF) leukocyte and peripheral WBC/PLT counts, and serum PCT measurements at admission were carried out prior to the use of antibiotics. Receiver operating characteristic (ROC) curves were generated to test the accuracies and cut-off values for different inflammatory markers.
  
  
  RESULTS
  Among the 94 infected patients, 66 tested positive by bacterial culture, for which the positivity of blood, ascites and other secretions were 25.8%, 30.3% and 43.9%, respectively. Lung infection, SBP and unknown sites of infection accounted for 8.5%, 64.9% and 26.6% of the cases, respectively. Serum PCT levels (3.02 ± 3.30 ng/mL) in DCPs with infections were significantly higher than those in control patients (0.15 ± 0.08 ng/mL); p < 0.05. We used PCT ≥0.5 ng/mL as a cut-off value to diagnose infections, for which the sensitivity and specificity was 92.5% and 77.1%. The area under the curve (AUC) was 0.89 (95% confidence interval: 0.84-0.91). The sensitivity and specificity were 62.8% and 94.2% for the diagnosis of infections, and were 68.8% and 94.2% for the diagnosis of SBP in DCPs when PCT ≥2 ng/mL was used as a cut-off value. For the combined PCT and WBC/PLT measurements, the sensitivity was 76.8% and 83.6% for the diagnosis of infections or SBP in DCPs, respectively.
  
  
  CONCLUSIONS
  Serum PCT levels alone or in combination with WBC/PLT measurements seem to provide a satisfactory early diagnostic biomarker in DCPs with infections, especially for patients with SBP.
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. caizhaohua_514@163.com.|Department of Internal Medicine, The Second Hospital Beijing, Beijing, Xicheng District, 100031, China. caizhaohua_514@163.com.
authors.forename: Zhao-Hua
authors.initials: ZH
authors.lastname: Cai
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. mmfan@163.com.
authors.forename: Chun-Lei
authors.initials: CL
authors.lastname: Fan
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. zhengjunfu1979@foxmail.com.
authors.forename: Jun-Fu
authors.initials: JF
authors.lastname: Zheng
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. cindy_zhang237@163.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. rourou0116@sohu.com.
authors.forename: Wen-Min
authors.initials: WM
authors.lastname: Zhao
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. libingyayy@163.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. 13699119545@163.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. peilingdong@sohu.com.
authors.forename: Pei-Ling
authors.initials: PL
authors.lastname: Dong
authors.affiliation: Department of Gastroenterology and Hepatology, Beijing You'an Hospital affiliated to Capital Medical University, Beijing, Fengtai District, 100069, China. dinghuiguo@medmail.com.cn.
authors.forename: Hui-Guo
authors.initials: HG
authors.lastname: Ding
mesh_terms: D000328:Adult; D000368:Aged; D001201:Ascites / Q000150:complications / Q000175:diagnosis / Q000382:microbiology; D001424:Bacterial Infections / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008103:Liver Cirrhosis / Q000150:complications* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D010538:Peritonitis / Q000097:blood / Q000150:complications* / Q000175:diagnosis* / Q000382:microbiology; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide