TNF-α increases in the CSF of children with acute lymphoblastic leukemia before CNS relapse

There is scarce information regarding the concentration of cytokines in cerebrospinal fluid (CSF) of children with acute lymphoblastic leukemia (ALL) and their clinical association with CNS status. A prospective analysis of 40 patients < 18 years with newly diagnosed ALL was performed. Human cytokine magnetic bead panel assay values of IL-2, IL-4, IL-6, IL-8, IL-10, MCP-1, TNF-α in CSF at diagnosis, end of induction to remission, and 6 months after diagnosis were determined. IL-6 and MCP-1 values showed a significant increment at the end of induction. From the whole group 4 (10.0%), patients relapsed to the CNS at a median of 11.48 months. A significantly higher value of TNF-α at third determination in these CNS-relapsed patients was documented, 7.48 vs. 2.86 pg/mL in 36 children without relapse (p = 0.024). TNF-α concentration increased at a median 5.48 months before CNS relapse. By receiver-operating characteristic curve (ROC) analysis, the best cut-off point of TNF-α concentration that better predicted CNS relapse was ≥ 1.79 pg/mL. In conclusion an increase in TNF-α concentration on CSF preceded CNS relapse in children with ALL. An increase in MCP-1 and IL-6 was not associated to CNS relapse and appears to result from an inflammatory response after IT injection of chemotherapy.