Kidney biopsy results versus clinical parameters on mortality and ESRD progression in 2687 patients with...

Physicians refer proteinuric patients to kidney biopsy in order to clarify the issue of underlying renal disease. We compared kidney biopsy results with classical outcome parameters in a large cohort of patients with biopsy proven glomerulonephritis (GN).

In a retrospective analysis, 2687 patients with different forms of GN from 123 Austrian centres were investigated. Patient characteristics, the diagnosis of GN and its respective subtype and clinical symptoms such as arterial hypertension, haematuria, amount of proteinuria and estimated glomerular filtration rate (eGFR) were tested for their association with all-cause mortality and progression to end-stage renal disease (ESRD).

During a median follow-up of 129·9 months (IQR 89·6; 177·7), 688 patients (25·6%) died and 718 patients required dialysis (29·4%). In multivariate Cox's regression analysis age (HR 1·06), female sex (HR 0·71), eGFR (HR 0·74), the diagnosis of GN and its subtypes predicted patient survival (all P < 0·01), whereas the amount of proteinuria was not associated with patient survival. The incidence of progression to ESRD was associated with female sex (HR 0·71), eGFR (HR 0·65), amount of proteinuria (HR 1·15) and the diagnosis of GN and its subtypes (all P < 0·01). Nephrotic or nephritic syndromes were not associated with patient survival or progression to ESRD and did not add further predictive value to outcome of GN.

Our study demonstrates histological diagnosis of GN and its specific subtype predicts patient survival and dialysis incidence. Therefore, kidney biopsy should be an integral part of routine diagnostic assessment in patients with any forms of suspected GN.