Overexpression of the IL-33/ST2 in Pediatric Acute Lymphoblastic Leukemia: Evaluation of the Effects of a Treatment Program

Background: The study focuses on B-acute lymphoblastic leukemia (B-ALL), a common childhood blood cancer marked by an overproduction of B lymphocytes. It explores the role of cytokine expression changes, particularly Interleukin-33 (IL-33), which has both anti- and pro-tumor effects. The research assesses the expression of IL-33 and its receptor, suppression of tumorigenicity 2 (ST2), in B-ALL patients before and after chemotherapy treatment. Materials and Methods: In this quasi-experimental investigation, peripheral blood specimens were taken from 33 newly-diagnosed/untreated ALL patients. An induction chemotherapy course was administered to ALL patients for 30 days following diagnosis. Blood samples were taken again after the completion of induction chemotherapy. 30 healthy individuals with matched age and gender were also recruited as a control group. Serum IL-33 quantities were assessed using the ELISA method. Total RNA was extracted from peripheral blood samples, and the gene expression of IL33 and ST2 was measured using real-time PCR. Results: In B-ALL patients, the pre-treatment serum IL-33 concentrations (33.89 ± 4.38 Pg/mL) were substantially greater than the healthy group (20.66 ± 2.20 Pg/mL, P<0.02). Pre-treatment expression of IL-33 and ST2 mRNA (1.79 ± 0.18 and 1.42 ± 0.18) was also significantly higher than those in the healthy group (1.00 ± 0.10 and 1.00 ± 0.09; P<0.001 and P<0.05, respectively). After chemotherapy, serum IL-33 concentrations (22.40 ± 2.60 Pg/mL) and mRNA expression of IL-33 (0.91 ± 0.15) were significantly reduced compared to pre-treatment levels (P<0.04 and P<0.001, respectively). There were no notable differences in serum IL-33 levels or mRNA expression of IL-33 and ST2 between controls and treated patients (P<0.61, P<0.63, and P<0.48, respectively). Conclusion: Greater expression of IL-33 and ST2 was observed in B-ALL patients, which were decreased at the end of a therapy course.