Increased frequency of activated regulatory T cells in patients with lupus nephritis

Abstract

Background and objective: Lupus nephritis (LN) is one of the common manifestations of systemic lupus erythematosus (SLE), affecting the quality of life of patients. Abnormality in the adaptive immune response, such as T cell response, plays the main role in the pathogenesis of SLE and LN. In this study, we aimed to evaluate the role of different subpopulations of regulatory T cells (Tregs) and effector T cells (Teff) in LN patients and compare them with SLE patients.

Materials and methods: A total of 48 participants were enrolled in this study and divided into 3 groups: (i) patients with SLE; (ii) patients with LN; and (iii) healthy controls (HCs). The frequencies of CD4⁺ CD25⁺⁺ CD45RA^- Foxp3^hi activated Tregs (aTregs), CD4⁺ CD25⁺ CD45RA⁺ Foxp3^lo resting Tregs (rTregs), CD4⁺ CD25⁺ CD45RA^- Foxp3^lo non-Tregs, CD4⁺ CD25⁺ Foxp3^- Teff, and Tregs were analyzed in all subjects using a flow cytometer.

Results: LN patients had a significantly increased frequency of aTregs and Tregs compared with SLE patients (standardized mean difference [SMD] = 0.50; 95% CI [-0.26, 1.25]; p > 0.05 and SMD = 0.60; 95% CI [-0.16, 1.36]; p > 0.05, respectively). Patients with LN had a significantly increased frequency of Teff compared with SLE patients (SMD = 0.49; 95% CI [-0.26, 1.24]; p > 0.05). However, an increased ratio of Tregs/Teff was observed in LN patients compared with SLE patients (SMD = -0.25; 95% CI [-0.97, 0.48]; p > 0.05).

Conclusion: Patients with LN showed immunoregulatory properties, in which both aTregs and Tregs had increased frequencies.

Keywords: Lupus nephritis; Systemic lupus erythematosus; Tregs; effector T cell; regulatory T cell.