OBJECTIVETo evaluate the diagnostic values of procalcitonin(PCT), C-reactive protein(CRP) and interleukin-6 (IL-6) in patients suffered from hematological diseases with bacterial infection, and to provide further evidence for clinical application.

METHODSA total of 3631 blood cultures, serum levels of PCT and CRP and IL-6 (n=1587) from the inpatients from 2014-01-02 to 2018-01-27 were retrospectively analyzed. The patients were divided into positive (n=208) and negative blood culture (n=3423) groups. Positive blood culture group were redivided into gram-positive (n=34) and gram-negative (n=174) subgroups. The values CRP, PCT and IL-6 were compared respectively in these groups. The data were analyzed by using R 3.4.4 language.

RESULTSThe medians of PCT values in positive and negative blood culture groups were 0.41(0.04-103.34) μg/L and 0.20(0.02-200) μg/L(P<0.001) respectively. The medians of CRP values in positive and negative blood culture groups were 9.49(0.1-370) mg/dl and 5.42(0-370) mg/dl (P<0.001) respectively. The medians of IL-6 values in positive and negative blood culture groups were 186.1(2.0-5000, n=91) pg/ml and 52.65(1.5-5000, n=1496) pg/ml (P<0.001). The medians of PCT values in gram-positive and gram-negative groups were 0.20(0.05-93.83) μg/L and 0.58(0.04-103.34) μg/L (P=0.006) respectively. The medians of CRP value in gram-positive and gram-negative groups were 9.19(0.1-35.3)mg/dL and 9.49(0.1-370) mg/dl (P=0.300) respectively. The medians of IL-6 values in gram-positive and gram-negative groups were 83.01(5.61-1500, n=12) pg/ml and 208(2.0-5000, n=79) pg/ml (P=0.357).

CONCLUSIONThe PCT, CRP and IL-6 levels were significantly higher in the positive blood culture group than those in the negative blood culture group, so provide the effective early diagnostic markers for blood culture. PCT levels in gram-positive group were significantly higher than that in gram-negative groups, contributing to distinguish between the 2 groups.