Urinary podocyte microparticles are associated with disease activity and renal injury in systemic lupus erythematosus

Abstract

Background New non-invasive biomarkers are demanded to identify renal damage in various autoimmune-associated kidney diseases. Glomerular podocyte damage mediated by systemic lupus erythematosus (SLE) plays an important role in the pathogenesis and progression of lupus nephritis (LN). This study evaluated whether the podocyte-derived microparticles (MPs) were novel biomarkers of clinical and histological features in SLE patients with LN. Methods A cross-sectional study, including 34 SLE patients and 16 healthy controls, was designed. Urinary annexin V + podocalyxin + MPs of all participants were quantified by flow cytometry. The correlation of podocyte-derived MPs with clinical and histological parameters of SLE patients was analysed. Results The number of annexin V + podocalyxin + MPs from urine samples were markly increased in patients with SLE. Furthermore, the level of urinary podocyte-derived MPs was positively correlated with the SLE Disease Activity Index (SLEDAI) score, anti-dsDNA antibody titre, erythrocyte sedimentation rate, and proteinuria. Conversely, it was negatively correlated with the level of complement C3 and serum albumin. The number of urinary podocyte-derived MPs was significantly increased in SLE patients with high activity indices. Receiver operating characteristic (ROC) curves were calculated to assess the power for podocyte-derived MP levels in differentiating between SLE patients with and without LN. Podocyte-derived MP levels were able to differentiate between SLE patients with mild disease activity, as well as those with moderate and above disease activity. SLE patients showed increased podocyte-derived MP excretion into the urine. Conclusions These findings suggest that the change in urinary podocyte-derived MP levels could be useful for evaluating and monitoring SLE disease activity.

Urinary MCP-1 and TWEAK as non-invasive markers of disease activity and treatment response in patients with lupus nephritis in South Africa

“…[26] Several studies have assessed for non-invasive ways of making a diagnosis or predicting increased disease activity in patients with LN. [11,25,27,28] Most of these studies have to those with non-active disease (P < 0.01) and also showed significant correlation between both biomarkers and kidney biopsy activity index (P < 0.01) but not with chronicity index of the biopsies (P > 0.05) [11] Similar findings have been reported by other studies. [12] Although our study did not demonstrate correlation between the biomarkers and renal activity scores, we think this may be related to the low sample size of our study given that other clinical and biochemical markers of activity were elevated at baseline and declined following treatment.…”

Podocyte-Released Migrasomes in Urine Serve as an Indicator for Early Podocyte Injury

“…In addition, an inverse correlation between urinary EVs and GFR was observed by Kamińska et al [16] in diabetic patients. Higher levels of podocyte-derived EVs were associated with podocyte injury in patients with renovascular hypertension [18] or lupus nephritis [19]. Urinary EVs can be also derived from other cell types.…”

Urinary MCP-1 and TWEAK as non-invasive markers of disease activity and treatment response in patients with lupus nephritis in South Africa

“…[26] Several studies have assessed for non-invasive ways of making a diagnosis or predicting increased disease activity in patients with LN. [11,25,27,28] Most of these studies have relied on the activated in ammatory milieu in the kidney during an active state of the disease for production of cytokines or increased loss of epithelial cells into the urine. TWEAK belongs to the TNF superfamily of structurally related cytokines and its gene is expressed in multiple kidney cells including mesangial, glomerular and tubular cells of the kidney.…”