Effect of Roux-en-Y gastric bypass on the short-term immune function in patients with type 2 diabetes mellitus

Objective: To investigate the effect of laparoscopic Roux-en-Y gastric bypass on the short-term immune function of type 2 diabetic patients and to explore the correlation between the immune regulatory effect and blood glucose control.

Methods: Clinical data of 28 patients with type 2 diabetes mellitus who underwent laparoscopic Roux-en-Y gastric bypass surgery in our hospital during January 2014 to January 2015 were retrospectively collected. Fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), immunoglobulin (IgG, IgA, IgM), T lymphocytes CD3(+), killer T cells CD3(+)CD8(+), helper T cells CD3(+)CD4(+), natural killer(NK) cell subsets CD16(+),CD56(+) and B cell subsets CD19(+),CD45(+) levels were detected and compared between before and after surgery. Correlation of immunoglobulin and immune cell subsets with the level of FBG and HbA1c were examined.

Results: After operation, FBG and HbA1c decreased significantly from (5.78±1.15) mmol/L to (14.21±1.89) mmol/L, and (9.96±0.97)% to (6.87±0.69)%, respectively (all P<0.05), and immunoglobulin (IgG, IgA, IgM) increased significantly [IgG: from(9.41±1.23) g/L to (12.74±1.61) g/L, IgM: from (1.71±0.22) g/L to (2.43±0.39) g/L, IgA: from (1.25±0.26) g/L to (1.97±0.23) g/L, all P<0.05]. Besides, T lymphocytes CD3(+), killer T cells CD3(+)CD8(+) and B cell subsets CD19(+)CD45(+) elevated significantly as well [T lymphocytes CD3(+): from (55.3±3.8)% to (67.6±4.6)%, killer T cells CD3(+)CD8(+): from (15.6±5.3)% to (28.7±4.2)%, B cell subsets CD19(+)CD45(+): from (8.4±3.7)% to (18.1±4.1)%, respectively, all P <0.05]. There was no significant difference in the expression of helper T cells CD3(+)CD4(+) and natural killer cell subsets CD16(+)CD56(+) between pre-operation and post-operation(all P>0.05). Levels of immunoglobulin (IgG, IgA, IgM), CD4(+)/CD8(+) ratio and B cell subsets were negatively correlated with HbA1c and FBG levels (IgG with FBG: r=-0.865, IgA with FBG: r=-0.887, IgM with FBG: r=-0.902, CD4(+)/CD8(+) with FBG: r=-0.956, CD19(+)CD45(+) with FBG: r=-0.834; IgG with HbA1C: r=-0.859, IgA with HbA1C: r=-0.957, IgM with HbA1C: r=-0.843, CD4(+)/CD8(+) with HbA1C: r=-0.912, CD19(+)CD45(+) and HbA1C: r=-0.885, all P<0.05), but the proportion of NK cells was not significantly correlated with HbA1c and FBG (P>0.05).

Conclusions: Laparoscopic Roux-en-Y gastric bypass has good effect on the immune function of patients with type 2 diabetes mellitus. Improvement of immune function is correlated with the control of FBG and HbA1c.