Renal biopsy in lupus nephritis.

Renal biopsy can be extremely valuable in the management of patients with lupus nephritis. It is remarkably common to find pathological evidence of substantial nephron loss in patients with low-grade laboratory abnormalities. This is due to compensatory hypertrophy and hemodynamic adjustments within the less-diseased nephron mass. It has been shown that the decision to institute immunosuppressive therapy is highly informed by the results of renal biopsy and offers the prospect of achieving more favorable renal outcomes. Kidney biopsies should be evaluated by dedicated renal pathology services experienced in diagnostic light, immunofluorescence and electron microscopy. Biopsies should be classified according to the World Health Organization (WHO) system and specific lesions semiquantitatively scored against a checklist of features comprising activity (reversible) and chronicity (irreversible damage) indices. The renal biopsy findings should be reviewed jointly by pathologists and the clinicians caring for patients with lupus nephritis.