Assessment value of interleukin-6, procalcitonin, and C-reactive protein early kinetics for initial antibiotic efficacy in patients with febrile neutropenia: A prospective study.

Background: This study aims to investigate the early kinetics of interleukin 6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) on initial antibiotic efficacy in hematological disorder patients with febrile neutropenia (FN).

Methods: A total of 40 patients with 43 episodes of FN were enrolled and divided into initial antibiotic effective group (IAE group, n = 24) and initial antibiotic ineffective group (IAI group, n = 19). The levels of IL-6, PCT, and CRP before antibacterial treatment (T0), and 12 h (T1), 24 h (T2), 48 h (T3), and 72 h (T4) post-antibacterial treatment were determined, respectively. Furthermore, the receiver operating characteristic curve (ROC) analysis was performed to evaluate the clinical value of indicators.

Results: In IAE group, the IL-6 levels gradually decreased from T0 to T4, and the CRP levels significantly decreased at 48 to 72 h, whereas both IL-6 and CRP remained at high levels in the IAI group. The PCT levels in both groups increased at the early stage of anti-infection (T1-T2) and reached to peak at T1-T2 in effective group. ROC curve analysis identified IL-6 as a predictive biomarker for initial antibiotic efficacy at 12, 48, and 72 h after treatment, with the AUC of 0.698, 0.744, and 0.821, respectively. In addition, CRP demonstrated predictive ability of initial antibiotics against infection at 24, 48, and 72 h after therapy, with the AUC of 0.724, 0.741, and 0.797, respectively. ROC curve analysis of percentage changes demonstrated that IL-6 percentage change showed predictive ability of antibiotic efficacy at the early stage, and both the IL-6 and CRP percentage changes showed the predictive ability of antibiotic efficacy 48 or 72 h after antibiotics therapy.

Conclusion: This study confirmed IL-6 and CRP levels, and the percentage change in IL-6 as the biomarkers for initial antibiotic efficacy prediction in hematological disorder patients with FN.