Abnormal distribution of peripheral lymphocyte subsets induced by PDAC modulates overall survival

The impairment of the immune system is prevalent in patients with malignancies, including pancreatic ductal adenocarcinoma (PDAC). The present study aimed to evaluate alternations of peripheral lymphocyte subsets in patients with PDAC, and also to assess the prognostic value of observed changes. We recruited 160 consecutive PDAC patients who had undergone radical surgical resection between 2010 and 2013. To investigate the prognostic factors, we detected the peripheral lymphocyte subsets in PDAC by flow cytometry, including T cells (CD3+, CD3+CD4+, CD3+CD8+, CD8+CD28+), regulatory T cells (Tregs, CD4+CD25+CD127-), natural killer cells (NK cells, CD3−CD56+) and B cells (CD19+). We also evaluated the clinical and pathological features of these patients. Survival analysis was performed by univariate and multivariate analyses. Our results indicated the profile of peripheral lymphocyte subsets undergone profound changes in PDAC patients. Univariate and multivariate analysis indicated the levels of peripheral lymphocyte subsets (CD19+ B cells, Tregs and CD8+CD28+ T cells) were independent predictors for overall survival. The results also suggested that the systemic impairment of immune system in patients with PDAC, was reversed when primary tumor was removed. The present study provided some evidences that the impairment of host immunity induced by PDAC may play a role in the survival of patients.