Elevated urinary monocyte chemoattractant protein-1 levels in children with Henoch-Schonlein purpura nephritis.

BACKGROUND: Chemokine monocyte chemoattractant protein-1 (MCP-1) has been proved as a potential urinary biomarker in nephropathies. The aim of this study was to investigate the urinary monocyte chemoattractant protein-1 (MCP-1) levels and clinical significance in Henoch-Schonlein purpura (HSP) children with and without nephritis and determine the association of MCP-1 with proteinuria. METHODS: A total of 261 HSP children-with or without nephritis-and 84 healthy control children were enrolled in this study. Of these, 126 HSP nephritis (HSPN) children were subdivided into three groups according to total urine protein in 24 h (TUP): Group A, mild proteinuria group with TUP <25 mg/kg; Group B, moderate proteinuria group with TUP ≥25 mg/kg and <50 mg/kg; Group C, severe proteinuria group with TUP ≥50 mg/kg. Urinary MCP-1 levels were determined by ELISA. Levels of serum creatinine (Cr), blood urea nitrogen (BUN), urinary α1-micro globulin (α1-MG), micro-albumin (mAlb), immunoglobulin G (IgG), transferrin (TRF) and TUP were performed to determine their associations with MCP-1. RESULTS: Urinary MCP-1 was significantly higher in HSPN group in comparison with HSP group and controls (P < 0.05), but no significant difference was found between the HSP group and the healthy group (P > 0.05). The levels of urinary MCP-1 increased in parallel to the enhancement of total urine protein in 24 h in HSPN patients. There were statistically significant differences among these three groups of HSPN children (p < 0.05). Urinary MCP-1 correlated positively with urinary α1-MG, mAlb, IgG, TRF and TUP in HSPN, whereas no correlation was observed with serum Cr and BUN. CONCLUSIONS: MCP-1 was elevated in children with HSPN and correlated with proteinuria. Urinary MCP-1 could be used as a suitable, non-invasive biomarker to provide valuable information not only for the diagnosis of HSPN, but also for evaluation of severity of renal damage.