Distributions and significance of LAP+ CD4+ Treg cells in the peripheral blood of patients with colorectal cancer

Abstract

Objective To explore the distributions of LAP+ CD4+ Treg cells in the peripheral blood of patients with colorectal cancer and its relationship with the clinicopathological factors. Methods The retrospective case-control study was adopted. The clinical data of 40 patients undergoing radical resection of colorectal cancer and 20 healthy volunteers who were admitted to the First Affiliated Hospital of Guangxi Medical University between April 2014 and October 2014 were collected. The proportion of LAP+ CD4+ Treg cells in the peripheral blood was detected by flow cytometry. Analysis indicators included: (1) proportion of LAP+ CD4+ Treg cells in the peripheral blood between patients with colorectal cancer and healthy volunteers, (2) relationship between clinicopathological factors and proportion of LAP+ CD4+ Treg cells in the peripheral blood, (3) correlation analysis of quantitative data on the clinicopathological factors related with proportion of LAP+ CD4+ Treg cells in the peripheral blood. Measurement data with normal distribution were presented as ±s, and comparison between groups was analyzed using the t test. Correlation analysis was done using the Pearson test. Results (1)Results of flow cytometry showed that proportion of LAP+ CD4+ Treg cells in the peripheral blood was 9.4%±2.9% in patients with colorectal cancer and 1.5%±0.7% in healthy volunteers, with a statistically significant difference (t=12.275, P<0.05). (2) Relationship between clinicopathological factors and proportion of LAP+ CD4+ Treg cells in the peripheral blood: proportion of LAP+ CD4+ Treg cells in the peripheral blood in patients with colorectal cancer was 8.5%±3.2% with serum carcinoembryonic antigen (CEA)<5.0 μg/L, 12.3%±3.0% with serum CEA≥5.0 μg/L, 8.1%±1.1% in stage A-B of Dukes staging, 10.8%±2.0% in stage C-D of Dukes staging, 11.4%±2.0% with lymph nodes metastasis and 9.3%±2.1% without lymph nodes metastasis, showing statistically significant differences in the different levels of CEA, Dukes staging and lymph node metastasis (t=2.783, -5.376, 3.276, P<0.05). (3) Correlation analysis: there was a positive correlation between serum CEA of patients with colorectal cancer and proportion of LAP+ CD4+ Treg cells in the peripheral blood, with a statistically significant difference (r=0.543, P<0.05). Conclusions The proportion of LAP+ CD4+ Treg cells in the peripheral blood of patients with colorectal cancer is increased, and it is also different among patients with different Dukes staging and lymph node metastasis. There is a positive correlation between serum CEA of patients with colorectal cancer and proportion of LAP+ CD4+ Treg cells in the peripheral blood. Key words: Colorectal neoplasms; LAP+ CD4+ Treg cells; Flow cytometer