Update on immunoglobulin a nephropathy. Part II: Clinical, diagnostic and therapeutical aspects

Table 3 Potential biomarkers for immunoglobulin a nephropathy

Biologics	Source	Rationale
Galactose deficient IgA1	Serum	Core antigen of the pathogenic IgA1 immune complex; leads to activation of mesangial cells and glomerulonephritis
Glycan-specific IgG	Serum	Form glycan-dependent complex with galactose-deficient IgA1; alanine to serine substitution in complementary-determining region 3 of IgG heavy chain; able to differentiate IgA nephropathy patients from controls with 88% specificity and 95% sensitivity
Activated complement C3	Serum	Up-regulated level in 30% of patients; correlated with deteriorating renal function
FGF 23	Serum	FGF23 serum levels are significantly associated with IgAN progression
Soluble CD89	Serum	Low levels in patients with disease progression compared with those without disease progression
Mannose-binding lectin	Urine	Significantly higher in patients than healthy controls; associated with histopathologic aggravations such as mesangial hypercellularity, tubular atrophy, interstitial fibrosis
EGF and MCP-1	Urine	An EGF/MCP-1 ratio greater than 366.66 extends renal survival to at least 84 mo in a cohort of 44 patients
Proteomic pattern	Urine	High throughput characterization of 2000 polypeptide using capillary electrophoresis on-line coupled to a mass spectrometer
microRNA profile	Urine	Sequencing identified microRNA profiling that is specific to IgA nephropathy

IgA1: Immunoglobulin A1; IgG: Immunoglobulin G; FGF23: Fibroblast growth factor 23; IgAN: Immunoglobulin a nephritis; RNA: Ribonucleic acid; EGF: Epidermal growth factor; MCP-1: Monocyte chemotactic peptide-1.