Evaluation of Th1/Th2 cytokines as a rapid diagnostic tool for severe infection in paediatric haematology/oncology patients by the use of cytometric bead array technology.

Haematology/oncology children are usually at risk for various infections after intensive chemotherapy. We evaluated the quantification of Th1/Th2 cytokines with a flow cytometric bead array (CBA) in 795 hospitalized haematology/oncology children (309 febrile and 486 afebrile patients) to seek for a diagnostic method for determination of the type and the severity of infection. Three hundred and nine febrile patients developed a total of 505 febrile episodes. Microbiological examination demonstrated a positive blood culture (microbiologically documented infection (MDI)) in 145/505 febrile episodes. The controls included 550 healthy children, 43 haemophagocytic lymphohistiocytosis (HLH) patients, 35 cytomegalovirus infection patients and 19 Epstein-Barr virus infection patients. Interleukin (IL)-4, IL-6, IL-10, tumour necrosis factor (TNF)-α and interferon (IFN)-γ levels in febrile episodes were significantly higher than those in healthy children, and the cytokine profile was different from that of the HLH controls or the viral infection controls. IL-6 levels were much higher in MDI patients (usually >1000.0 pg/mL, 60/145) than in HLH patients (2/43); however, IFN-γ levels were only slightly increased in MDI patients, rarely being more than 100.0 pg/mL (8/145 vs. 39/43 in HLH patients). The median levels of IL-4, IL-6, IL-10, TNF-α and IFN-γ in febrile patients before antibiotic therapy were 3.9, 660.1, 122.7, 6.9 and 11.4 pg/mL, respectively, and returned to 3.3, 22.8, 9.6, 4.1 and 6.4 pg/mL, respectively, after infection was controlled. IL-6 and IL-10 levels were positively associated with septic shock and mortality rates. In conclusion, our results have demonstrated the usefulness of IL-6/IL-10/TNF-α/IFN-γ determination with CBA technology for the early rapid diagnosis, severity evaluation and assessment of therapy effect in febrile haematology/oncology children.