Plasma fractalkine levels are associated with renal inflammation and outcomes in immunoglobulin A nephropathy

BACKGROUND

A recognized noninvasive biomarker to improve risk stratification of immunoglobulin A nephropathy (IgAN) patients is scarce. Fractalkine has been shown to play a key role in glomerular disease as chemoattractant, adhesion and even fibrosis factor. The current study assessed the possibility of plasma fractalkine as a novel biomarker in IgAN patients.

METHODS

Plasma fractalkine was measured in 229 patients with renal biopsy consistent IgAN from 2012 to 2014, and clinical, pathological and prognostic relationships were analyzed.

RESULTS

The plasma fractalkine levels in IgAN patients were significantly correlated with the creatinine level and 24-h urine protein by both univariate and multivariate analysis. Mesangial hypercellularity was still significantly correlated with the plasma fractalkine levels even after adjustment for other potential predictor variables by multivariate analysis. In addition, the counts of CD20+ B cells or CD68+ macrophage in renal biopsies of IgAN patients were significantly correlated with the plasma fractalkine levels, but not CD4+ and CD8+ T cells. Finally, we concluded that patients with higher plasma fractalkine levels had higher risk of poor renal outcome compared with those with lower plasma fractalkine levels. No association was observed between the CX3CR1 polymorphisms and clinical parameters including plasma fractalkine levels and prognosis. Recombinant fractalkine induced mesangial cells extracellular matrix synthesis and promoted the migration of microphage cells RAW264.7.

CONCLUSIONS

Plasma fractalkine levels were associated with creatinine level, 24-h urine protein, mesangial hypercellularity pathological damage, the CD68+ macrophage and CD20+ B cell infiltration in renal tissue and renal outcome in IgAN patients. Plasma fractalkine might be a potential prognosis novel predictor in Chinese patients with IgAN.

Plasma chemokine CXC motif-ligand 16 as a predictor of renal prognosis in immunoglobulin A nephropathy

Background

There are few non-invasive biomarkers that have been identified to improve the risk stratification of patients with IgA nephropathy (IgAN). CXCL16 has been shown to play a key role as a chemoattractant, adhesion, and fibrosis factor in inflammatory disease. This study evaluated the potential for CXCL16 plasma as a potential biomarker in patients with IgAN.

Methods

Plasma CXCL16 was measured in 230 patients with renal biopsied IgAN enrolled from 2012 to 2014. The patients were followed for 41.3 months, with a 50% reduction in estimated glomerular filtration rate or end-stage renal disease as endpoints.

Results

The plasma CXCL16 levels in IgAN patients were strongly correlated with the uric acid, estimated glomerular filtration rate and tubular atrophy/interstitial fibrosis score in multivariate analysis. Furthermore, counts of CD4⁺ T cells, CD8⁺ T cells, and CD20⁺ B cells in renal biopsies of IgAN patients were significantly correlated with the plasma CXCL16 levels, but not CD68⁺ macrophage. Lastly, we concluded that patients with higher levels of plasma CXCL16 had an increased risk of poor renal outcome compared to those with lower levels. There was no association between the polymorphisms and clinical parameters of CXCL16, including the levels and prognosis of plasma CXCL16.

Conclusions

Plasma CXCL16 levels were associated with clinical parameters; pathological damage; CD4⁺ T cell, CD8⁺ T cell, and CD20⁺ B cell infiltration in renal tissue; and renal outcome in IgAN patients. Plasma CXCL16 might be a potential prognosis predictor in Chinese IgAN patients.