Is membranous nephropathy only a glomerular disease?

Tubulointerstitial lesions represent not only a constant component of the pathology of a "classical" glomerular disease such as idiopathic membranous nephropathy but also the most important prognostic indicator and a new "target" for its treatment. Proper "quantification" of the cellular events occurring within the interstitium may enable us to accurately assess the amount of disease activity and identify patients who might benefit from treatment.