Clinical Implications of CD4+CD25+Foxp3+Regulatory T Cell Frequencies After CHP-MAGE-A4 Cancer Vaccination

Background/Aim: The aim of this study was to explore whether the treatment effect or immune response to a cancer vaccine can be predicted by the percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) in peripheral blood mononuclear cells (PBMCs) after vaccination. Patients and Methods: Sixteen patients (9 men, 7 women; median age 61.5 years) enrolled in the CHP-MAGE-A4 cancer vaccine clinical trial who had a fixed dose (300 mu g of CHP-MAGE-A4 cancer vaccine and 0.5 Klinische Einheit (KE) of OK432 and received at least four vaccinations were investigated. Safety, immune response, and clinical effects were assessed before and after the cancer vaccination. Results: Treg ratios that remained low both before and after vaccination were associated with a good prognosis, and a low Treg/CD4 lymphocyte ratio 7-weeks after the initial vaccination was correlated with a better prognosis. Conclusion: The Treg ratio following vaccination appears to have some utility for predicting patient prognosis.