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.