Alterations in Cellular Immune Markers Among Patients with Type 2 Diabetes Mellitus Compared to Healthy Controls

Introduction: In addition to hyperglycemia, type 2 diabetes mellitus (T2DM) is a chronic metabolic disease marked by immunological dysregulation and low-grade systemic inflammation. Changes in cellular immune markers, including CD4⁺ and CD8⁺ T lymphocytes, have been identified as important factors in the pathophysiology and consequences of type 2 diabetes. Aim/Objective: This study aimed to evaluate the alterations in cellular immune markers among patients with T2DM compared to age- and sex-matched healthy controls. Methods: A comparative cross-sectional study with 240 participants—140 T2DM patients and 100 healthy controls—was conducted in Edo State, Nigeria. Peripheral blood samples were collected and analyzed for cellular immunological markers (CD4⁺, CD8⁺, and β-cells) using flow cytometry. ELISA and atomic absorption spectrophotometry were employed to detect the amounts of heavy metals (Pb, Hg, and As) and inflammatory cytokines (IL-6, TNF-α, and hs-CRP), respectively. SPSS version 26.0 was used to statistically analyze the data, with a significance level of p<0.05. Results: Compared to controls (CD4⁺: 812.3 ± 141.6; CD8⁺: 520.8 ± 77.9; p<0.001), T2DM patients had significantly lower CD4⁺ counts (582.6 ± 132.4 cells/μL) and CD8⁺ counts (371.4 ± 89.3 cells/μL). Subjects with type 2 diabetes had higher levels of TNF-α (47.8 ± 5.9 pg/mL), IL-6 (62.4 ± 7.1 pg/mL), and hs-CRP (6.1 ± 1.2 mg/L) (p<0.001). Immune indicators were shown to be significantly correlated with glucose indices and illness duration. Conclusion: This work demonstrates that cellular immunological dysregulation, which is marked by elevated inflammatory cytokines and reduced CD4⁺ and CD8⁺ T cells, is prevalent in type 2 diabetes. The intensity and complications of the disease may be influenced by these immunological disruptions.