The Association between (CD4+CD8+CD28) T-Reg cells and the Disease Activity in Systemic Lupus Erythematosus Patients

Background CD28, a key T-cell co-stimulatory molecule, is implicated in immune dysregulation in SLE patients, potentially serving as a biomarker for the disease activity. Objectives This research pointed to evaluate relations between CD4 + CD28+ and CD8 + CD28+ T-cell percentages and SLE activity (SLEDAI-2K), clinical/laboratory markers. Methods This cross-sectional study involved 100 people (34 controls, 66 SLE patients diagnosed according to EULAR/ACR criteria and stratified by SLEDAI-2K into group with mild activity [n = 33] and group with high activity [n = 33]). Flow cytometry quantified CD28 presence on CD4+/CD8 + T-cells. Results High-activity SLE featured more hypertension 36.4% vs 21.2% in low activity patients, renal issues (proteinuria 66.7%, hematuria 48.5%, casts 42.4%; all P < 0.001), pancytopenia, higher ESR/CRP/anti-dsDNA, and lower C3/C4. CD28 + T-cells declined stepwise from controls (CD4 + CD28: 12.7 ± 3.8%) to ,(8.1 ± 3.1%) in low activity SLE to (4.6 ± 3.2%) in high activity SLE. On the other hand CD8 + CD28 controls: (9.1 ± 3.8%) mildly elevated to(11.2 ± 5.5%) in low-activity SLE then declined again to (4.1 ± 2.8%) in high-activity SLE (all P < 0.001). These showed strong inverse correlations with SLEDAI-2K score(r = − .564 for CD4 + CD28 and r = − .685 for CD8 + CD28, all p value < 0.001). and remained independent predictors in multivariate regression analysis (B = − 0.83 and − 0.84, respectively; both P < 0.001), even after adjustment for age and disease duration. Conclusions Reduced CD4⁺CD28⁺ and CD8⁺CD28⁺ T cells percentage independently predict severe disease activity in SLE, outperforming traditional biomarkers and representing a high-fidelity indicator for disease flares and renal involvement.