BACKGROUND : Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that impacts several organ systems. Regulatory T cells (Tregs) are essential for maintaining immunological tolerance, and their dysregulation has been found linked to the pathogenesis of SLE. This study aimed to evaluate the correlation between CD4⁺CD25⁺FOXP3⁺ Treg levels and disease activity, as measured by the MEX-SLEDAI score, in patients with SLE. METHODS : A cross-sectional study was conducted involving 40 SLE patients treated in the Allergy and Immunology outpatient clinic and inpatient ward of Mohammad Hoesin Hospital from June 1, 2024 to August 31, 2024. Inclusion criteria were adults (≥18 years) diagnosed with SLE who provided informed consent. Exclusion criteria included other history autoimmune or immunocompromised conditions, pregnancy or lactation, hormonal contraceptive use, and active severe infection. CD4⁺CD25⁺FOXP3⁺ Treg cell levels were measured by flow cytometry. Disease activity was assessed using the MEX-SLEDAI score. Spearman’s correlation test was used to analyze the association between Treg levels and disease activity. RESULTS : Of 40 enrolled subjects (39 women, 1 man), 75% were aged 20–44 years. Mucocutaneous manifestations were the most common clinical feature (95%). Nephritis and hematologic involvement were most frequently observed in patients with severe disease activity. A strong negative correlation was identified between CD4⁺CD25⁺FOXP3⁺ Treg cell levels and MEX-SLEDAI scores (R = –0.72, p<0.001), indicating that lower Treg levels were associated with higher disease activity. CONCLUSIONS CD4⁺CD25⁺FOXP3⁺ Treg levels show a significant negative correlation with MEX-SLEDAI disease activity in SLE. Lower Treg cell levels reflect more severe disease activity.
disease progression ; flow cytometry ; systemic lupus erythematosus ; Treg cells