Phenotypical evaluation of lymphocytes and monocytes in patients with type 2 diabetes mellitus in Saudi Arabia.

OBJECTIVES: To evaluate the levels of total lymphocytes, B-lymphocytes (CD19+), T-lymphocytes (CD3+), natural killer (NK) cells (CD3-/CD56+), and monocyte subsets in type 2 diabetes mellitus (T2DM) patients in Saudi Arabia. In addition, this study aimed to evaluate whether B- and T-lymphocyte subsets are frequently altered in patients with T2DM. METHODS: A case-control study included 95 participants recruited in the study: 62 patients with T2DM and 33 healthy individuals. All the patients were admitted to the Diabetic Centre in Taif, Saudi Arabia. Blood samples were collected between April and August 2022. The hemoglobin A1c (HbA1c) level was evaluated in all patients. Flow cytometry was used to measure the expression of B-lymphocyte, T-lymphocyte, NK cells, and monocyte markers. The unpaired t-test was carried out to evaluate the differences in these markers between T2DM patients and healthy individuals. RESULTS: Patients with T2DM were associated with a lower percentage of total lymphocytes, higher percentage of B-lymphocytes, naive, and memory B subsets. In addition, patients with T2DM showed lower percentage of total T-lymphocytes (CD3+) and CD4 T-cells, but higher CD8 T-cell expression. Also, the NK-cell level was reduced in patients with T2DM, and the levels of monocyte subsets were altered. CONCLUSION: These data suggested that levels of lymphocytes and monocytes are impaired in T2DM patients, and this might be associated with the higher risk of infections observed in these patients.