OBJECTIVETo 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.

METHODSClinical 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.

RESULTSAfter 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).

CONCLUSIONSLaparoscopic 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.