Artikel
Comparing urinary macrophages, B cells and T cell subsets in Lupus nephritis: New insights into pathogenesis and potential biomarkers
Suche in Medline nach
Autoren
Veröffentlicht: | 12. September 2014 |
---|
Gliederung
Text
Background: Urinary T cells are increased in patients with proliferative Lupus nephritis (LN) and function as a noninvasive biomarker. However, little is known about the presence of other T cell subsets, B cells and macrophages in the urine although they may further improve the validity of urinary cellular biomarkers for LN.
Methods: We analyzed urine and blood samples of 98 SLE patients as well as urine samples of 14 patients with diabetic nephropathy (DN) and 11 patients with anti-neutrophil cytoplasmatic antibody associated vasculitis (AAV) by flow cytometryfor the presence of T cells subsets, B cells and macrophages.SLE patients withcurrent biopsy-proven LN or a combination of SLE Disease Activity Index (SLEDAI) ≥10 and renal SLEDAI ≥8 were considered as active LN patients(n=19) while all other SLE patients were assigned to a non-active group (n=79).
Results: The number of urinary CD4+ and CD8+ T cells, CD19+ B cells and CD14+ macrophages were significantly higher in patients with active LN when compared toother SLE patients. Urinary T cells showed excellent distinction of patients with active LN, CD8+ T cells (AUC of ROC=1.000) and CD4+ T cells (AUC of ROC=0.9969) alike. Urinary CD19+ B cells (AUC of ROC=0.7823) and CD14+ macrophages (AUC of ROC=0.9066) failed to reach these high standards. Patients with DN or AAV also showed increased urinary cell counts, although the urinary CD4/CD8-ratio is significantly lower (p=0.0006) in SLE patients than in DN patients. Urinary CD4+ T cells of active LN patients proved to be mainly of effector memory phenotype and have significantly higher CD40L and ki67 expression than corresponding blood cells; no enrichment of regulatory T cells was found.
Conclusion: Despite of detectable urinary cell counts for both B cells and macrophages, urinary T cells remain the best urinary cellular biomarker for LN. Urinary cells are also detectable in DN and AAV but the lower CD4/CD8-ratio in LN might help distinguishing the diseases.