Serum interleukin-33 and soluble suppression of tumorigenicity 2 in pediatric leukemia with febrile neutropenia.

The purpose of this study was to evaluate the association between interleukin-33 (IL-33) and its receptor Soluble Suppression of Tumorigenicity-2 (sST2) levels and bacterial infections during febrile neutropenia (FN) in pediatric patients with acute lymphoblastic leukemia (ALL). In this prospective, case-control study, participants were divided into 3 groups: ALL patients with FN (Group A), ALL patients without neutropenia and fever (Group B), and healthy children without infection and chronic disease (Group C). There were 30 cases in each group. Blood samples for IL-33 and sST2 have been drawn from patients in Group A before the initiation of treatment and on days 1 and 5 of treatment, and from patients in Groups B and C at initiation. At admission, mean IL-33 level (39.02 ± 26.40 ng/L) in Group B and mean sST2 level (185.3 ± 371.49 ng/ml) in Group A were significantly higher than the other groups (p = 0.038, p < 0.001, respectively). No difference was observed in the mean IL-33 and sST2 levels in the 5-day follow-up of patients in Group A (p = 0.82, p = 0.86, respectively). IL-33 and sST2 levels were not associated with fever duration, neutropenia duration or length of hospitalization. While C-reactive protein (CRP) was significantly higher in patients with positive blood culture (p = 0.021), IL-33 (p = 0.49) and sST2 (p = 0.21) levels were not associated with culture positivity.  Conclusion: IL-33 and sST2 levels were not found valuable as diagnostic and prognostic markers to predict bacterial sepsis in patients with FN. What is Known: • Neutropenic patients are at high risk of serious bacterial and viral infections, but the admission symptom is often only fever. • Febrile neutropenia has a high mortality rate if not treated effectively. What is New: • Febrile neutropenia is not only caused by bacterial infections. Therefore, new biomarkers should be identified to prevent overuse of antibiotics. • Specific biomarkers are needed to diagnose bacterial sepsis in the early phase of febrile neutropenia.