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

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.

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.

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).

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