A recent study comparing lupus nephritis and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has uncovered differences in the presence of regulatory T cells (Tregs) in renal tissue.
“Although this is a small study which impedes any firm conclusions, our findings suggest that Tregs are involved in the control of inflammatory processes in lupus nephritis but seem to be of less importance in AAV,” the authors wrote in Clinical Rheumatology.
“The relative absence of FOXP3 + [referring to forkhead box P3, a transcription factor] T cells in AAV is surprising given the notion that Tregs tend to accumulate in inflammatory infiltrates in various tissues and diseases. The underlying reasons for this warrant further studies of AAV.”
According to the results, 8 of 12 (67%) patients with lupus nephritis showed positive tissue staining for Foxp3 at baseline, primarily within inflammatory infiltrates, but also interstitially and in a periglomerular pattern.
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After immunosuppressive treatment, the analysis of second biopsies revealed that 4 of 12 (33%) still exhibited detectable Foxp3+ cells, mainly found in persisting inflammatory infiltrates and to a lesser degree in the interstitium.
In contrast, among the patients with AAV, only 2 of 7 (29%) displayed positive staining for Foxp3 at baseline, particularly within inflammatory infiltrates and to a lesser degree in the interstitium, despite the presence of substantial areas of inflammatory infiltrates in all patients. During follow-up, 2 of 7 (29%) biopsies still showed positive Foxp3 expression.
Notably, lupus nephritis patients with a favorable clinical response to treatment exhibited higher numbers of Foxp3+ cells in the renal tissue at first biopsies compared to nonresponders.
The investigation involved the examination of kidney biopsies from 7 patients with AAV and 12 patients with lupus nephritis, both during active disease and after immunosuppressive treatment.
Reference
Zickert A, Janković MR, Malmström V, Chemin K, Gunnarsson I. Occurrence and localization of FOXP3+ cells in kidney biopsies in lupus nephritis and ANCA-associated vasculitis. Clin Rheumatol. Published online June 27, 2023. doi:10.1007/s10067-023-06676-8
