Role of Therapeutic Apheresis in the Treatment of Idiopathic Nephrotic Syndrome

Abstract

Idiopathic NS (INS) is characterized by diffuse foot process effacement on electron microscopy and minimal changes (minimal change nephropathy [MCN]), or focal segmental glomerular sclerosis (FSGS) on optical microscopy. MCN is the most common form of INS in children and is sensitive to corticosteroid therapy in almost cases. FSGS is more common in adult patients and has a less favourable course. Most of drug resistant patients develop terminal renal failure in 6–8 years. Moreover, FSGS reappears in many cases after renal transplantation. Genetic or secondary forms of INS have been identified and their response to therapy is unpredictable, whereas the recurrent forms in transplanted kidney are considered a more omogeneous group. Sera from patients with FSGS may contain some proteinuric or permeability factors (PFs), which have been partially identified. Corticosteroids and immunosuppressive drugs are the mainstay of the standard therapy. In steroid resistant cases, new therapeutic strategies directed against the action of PFs are under evaluation. The removal of PFs by means of Plasmapheresis or selective aphesis has been associated with proteinuria reduction. In this review we will analyze the preliminary results of the new therapies and the main studies on apheretic treatment in steroid resistant patients affected by INS.