Sirolimus has been associated with high-range proteinuria when used in replacement of
calcineurin inhibitors in renal transplant recipients with chronic allograft nephropathy (CAN).
Primary FSGS was demonstrated previously in some such patients, but the coexistence of
CAN lesions made the interpretation uneasy. However, nephrotic syndrome and FSGS were
observed recently in three patients who received sirolimus de novo, without medical history
of primary FSGS or CAN. Markers of podocyte differentiation were studied in kidney biopsies …