Biomarkers in Renal Vasculitis

Abstract

The use of biomarkers in glomerular diseases has been subject of investigation during the last decades, as it can provide worthwhile evidence in diagnosis, but also, it can guide treatment and give information about prognosis and response. Renal biopsy is still the compulsory technique to establish diagnosis, and also to offer information about the severity of renal damage. However, as an invasive method, it cannot be regularly performed during follow up, so the need to find and establish measurement of molecules, easily collected, which are associated with disease pathogenesis and predict renal function outcome seems very attractive to nephrologists. The renal complications of systemic vasculitis are very important for the outcome of the disease, and several substances and molecules, such as inflammatory cells, autoantibodies, cytokines, chemokines and growth factors are produced and may serve as biomarkers to provide useful information for diagnosis, follow up of the disease.

New Biomarkers for Systemic Necrotizing Vasculitides

“…In patients with IgA vasculitis (IgAV), increased serum levels of poorly galactosylated IgA1 remain the most consistent finding in patients with IgA nephritis and IgA nephropathy [7]. Renal biopsy is essential for diagnosing IgAV-N, probably guiding treatment and predicting outcome; the procedure cannot be used repeatedly during patient follow-up [31]. In patients with active AAV, there were significantly higher urinary levels of Bb, C3a, C5a, and soluble C5b-9 [20].…”

“…However, serum sCD163 levels failed to distinguish infections from active disease, which may limit its use [40]. A multicenter study showed that urinary CD89 and transglutaminase2 (TG2) concentrations are significantly lower in patients with active IgA vasculitis and nephritis compared to individuals whose disease has gone into complete or partial remission [31]. Incomplete B-cell depletion and repopulation after treatment with rituximab have been associated with a significantly higher rate of relapses in AAV patients [41].…”