Evaluation of serum procalcitonin, serum interleukin-6, and interleukin-8 as predictors of serious infection in children with febrile neutropenia and cancer.

BACKGROUND

Early diagnosis of sepsis in children with febrile neutropenia remains difficult owing to non-specific clinical and laboratory signs of infection. There is a need to assess the utility of inflammatory markers in clinical risk assessment for their ability to discriminate between low-risk and high-risk neutropenic patients since presently there is insufficient data to recommend their routine use.

METHODS

This is a prospective study of children on therapy admitted with febrile neutropenia and sampled for serum procalcitonin (PCT), interleukin-6 (IL-6), and interleukin-8 (IL-8) at admission. The febrile neutropenia episodes were categorized into two groups - Group I: no focus of infection and Group II: clinically/microbiologically documented infection. Statistical analyses for comparison were performed using Z-test and receiver operating curves at various cut-off levels.

RESULTS

A total of 46 episodes of febrile neutropenia in 33 children were analyzed. In total, 76% were categorized as group I and 24% as group II. The mean value of PCT in group II was higher (28.07 ng/mL) than group I (1.03 ng/mL) though there was no significant statistical difference. At a cut-off level of 2 ng/mL for PCT, sensitivity of 63%, specificity of 91%, positive predictive values (PPV) of 70%, and negative predictive value (NPV) of 88% were observed. There was no significant difference in the IL-6 and IL-8 levels between both the groups. However, at an optimal cut-off value of 50 pg/mL, IL-6 had an NPV of 80% and at a cut-off level of 130 pg/mL, IL-8 had an NPV of 73%, however, with low sensitivity and specificity.

CONCLUSION

IL-6, IL-8, and PCT can be utilized to define a group of patients with a low risk of sepsis in view of their favorable NPV. The use of these biomarkers together can facilitate early discharge from the hospital, and the use of oral antimicrobial therapy, in turn, reducing the cost of supportive therapy in a developing country.