Value of serum PCT in early diagnosis of bacterial infection in patients with liver failure

Objective To investigate the value of serum procalcitonin (PCT) in early diagnosis of bacterial infection in patients with liver failure. Methods A total of 463 patients with hepatitis B were selected from January to December, 2014, in the Department of Infectious Diseases, Taihe Hospital. According to the degree of liver injury, the patients were divided into four groups: mild liver injury group (n =120) , moderate liver injury group (n = 222) , sever liver injury group (n = 53) , and liver failure group (n = 68) . Serum PCT was measured for all patients, and the white blood cell count (WBC) and high-sensitivity C-reactive protein (hs CRP) were measured for patients with liver failure. The clinical manifestations were observed and recorded. The t test was used for comparison of normally distributed continuous data, while the Kruskal-Wallis H test was used for non-normally distributed continuous data; the Mann-Whitney U test was used for pairwise comparison of continuous data. The chi-square test was used for comparison of categorical data. The receiver operating characteristic (ROC) curve was used for the analysis of predictive value. Results The liver failure group had a significantly higher PCT level than the severe liver injury group, moderate liver injury group, and mild liver injury group (0. 81[0. 34-2. 15] vs 0. 53[0. 21-1. 59 ], 0. 35[0. 10-1. 18], and 0. 17[0. 10-0. 60], χ2= 25. 091, P < 0. 05) . The liver failure patients with PCT levels of < 0. 25 ng/ml (n = 10) , 0. 25-0. 5 ng/ml (n = 10) , and > 0. 5 ng/ml (n = 48) had infection rates of 20%, 30%, and 66. 7%, respectively, with a significant difference between the patients with a PCT level of > 0. 5 ng/ml and those with PCT levels of < 0. 25 ng/ml and 0. 25-0. 5 ng/ml (χ2=5. 631, 4. 650, P = 0. 018, 0. 031) . Among the liver failure patients, the infection cases had significantly higher PCT, WBC, and hs CRP than the non-infection cases (PCT: 3. 72 ± 1. 33 ng/ml vs 0. 34 ± 0. 12 ng/ml, t =-2. 547, P = 0. 015; hs CRP: 16. 70 ± 7. 03 mg/L vs11. 00 ± 6. 52 mg/L, t =-3. 458, P = 0. 001) ; the hs CRP level in both infection and non-infection cases was higher than the normal value, and the WBC in both infection and non-infection cases was lower than the normal value. In the 37 liver failure patients with infection, 13 (35. 14%) had no symptoms and signs associated with infection, but had significantly increased serum PCT. As for the predictive value of PCT for bacterial infection, the area under the ROC curve was 0. 691, with a sensitivity of 0. 737 and a specificity of 0. 700. Conclusion The patients with liver failure are susceptible to bacterial infection. Serum PCT measurement has great significance for early diagnosis of bacterial infection in patients with liver failure.