Response to the Letter to the Editor Entitled “Integrating Tissue Proteomics and Urinary Analysis to Capture Dynamic Podocyte Injury”

We thank Angeletti and colleagues for their compliments.[1] Our study, demonstrated marked loss in podocyte proteins in kidney biopsies of adult patients with minimal change disease (MCD), primary and secondary focal segmental glomerulosclerosis (FSGS) compared to membranous nephropathy (MN).[2] However, while cluster analysis demonstrated tight clustering of proteins in MCD, primary and secondary FSGS, there were large variations in MN, suggesting significant protein depletion in some cases. We speculate that in MCD and primary FSGS, circulating permeability factor(s) and/or antibody are so toxic to the podocyte that they cause an abrupt and massive disruption in multiple proteins simultaneously, while in MN a more selective and delayed injury occurs.