Effect of induction therapy on circulating T-helper 17 and T-regulatory cells in active proliferative lupus nephritis.

INTRODUCTION: T-helper 17 (Th17) cells and T-regulatory (Treg) cells have been suggested to play pathogenic roles in lupus nephritis. The in vivo effects of current therapies for lupus nephritis (LN) on these cells have not been adequately studied.

METHODS: We conducted a prospective observational study among patients with active proliferative lupus nephritis (LN) who received Eurolupus induction therapy and assessed them as per the European League Against Rheumatism criteria for renal response. Peripheral circulatory Th17 and Treg cell numbers were enumerated at start of therapy, at 3 and 6 months follow-up periods using flow cytometry. Baseline values were compared with inactive lupus patients (iSLE) and healthy controls (HC).

RESULTS: Thirty patients with LN, 20 iSLE and 22 HC were enrolled into the study. In LN, Th17 frequency was significantly higher compared to HC, and Treg frequency significantly lower compared to both iSLE and HC. Nineteen patients fulfilled criteria for response (partial or complete) at 6 months. Responder group showed a significant decline in Th17 frequency and an increasing trend in Treg frequency compared to baseline after 6 months of therapy.

CONCLUSION: Circulating Th17 cells were significantly raised in patients with active proliferative LN and showed a significant reduction in responder patients following therapy.