Circulating T-regulatory Cells in Neuroblastoma: a Pilot Prospective Study

The objective of our study was to determine baseline Tregs in neuroblastoma patients and correlate with patient characteristics, their change with therapy and at relapse/progression. Flow-cytometric analysis for Treg cells [CD4+CD25+FoxP3+] was done in 14 de novo neuroblastoma patients at diagnosis, post-neoadjuvant chemotherapy and at relapse/progression, along with six healthy controls. Patients had significantly higher baseline Treg frequency than controls [Mean 9.84 ± 3.84 vs 3.16 ± 1.49, P < .001]; higher mean Treg frequency in patients with tumors >10 cm (P = .004) and there was significant reduction in Treg frequency with neoadjuvant chemotherapy when compared with the baseline value [Mean 3.07 ± 1.24 vs 9.72 ± 3.84, P = .007].