Published online Oct 21, 2015. doi: 10.3748/wjg.v21.i39.11168
Peer-review started: July 6, 2015
First decision: July 19, 2015
Revised: August 2, 2015
Accepted: August 30, 2015
Article in press: August 30, 2015
Published online: October 21, 2015
Processing time: 108 Days and 18.3 Hours
AIM: To investigate the association of plasma levels of interleukin (IL)-6 and -8 with Wilms’ tumor 1 (WT1)-specific immune responses and clinical outcomes in patients with pancreatic ductal adenocarcinoma (PDA) treated with dendritic cells (DCs) pulsed with three types of major histocompatibility complex class I and II-restricted WT1 peptides combined with chemotherapy.
METHODS: During the entire treatment period, plasma levels of IL-6 and -8 were analyzed by ELISA. The induction of WT1-specific immune responses was assessed using the WT1 peptide-specific delayed-type hypersensitivity (DTH) test.
RESULTS: Three of 7 patients displayed strong WT1-DTH reactions throughout long-term vaccination with significantly decreased levels of IL-6/-8 after vaccinations compared with the levels prior to treatment. Moreover, overall survival (OS) was significantly longer in PDA patients with low plasma IL-6 levels (< 2 pg/mL) after 5 vaccinations than in patients with high plasma IL-6 levels (≥ 2 pg/mL) (P = 0.025). After disease progression, WT1-DTH reactions decreased severely and were ultimately negative at the terminal stage of cancer. The decreased levels of IL-6/-8 observed throughout long-term vaccination were associated with WT1-specific DTH reactions and long-term OS.
CONCLUSION: Prolonged low levels of plasma IL-6/-8 in PDA patients may be a prognostic marker for the clinical outcomes of chemoimmunotherapy.
Core tip: We recently reported a phase 1 clinical study in pancreatic cancer patients using dendritic cells (DCs) pulsed with multiple major histocompatibility complex class I and II-restricted Wilms’ tumor 1 (WT1) epitopes (DC/WT1-I/II) in combination with chemotherapy. Little is known about the prognostic markers for the clinical outcomes of chemoimmunotherapy. We examined the association of plasma levels of interleukin (IL)-6/-8 with WT1-specific immune responses and clinical outcomes in pancreatic cancer patients treated with chemotherapy combined with DC/WT1-I/II. The study demonstrates that prolonged low levels of plasma IL-6/-8 in pancreatic ductal adenocarcinoma patients may be a prognostic marker for the clinical outcomes of chemoimmunotherapy.