Anti-Neurofascin-Associated Nephrotic-Range Proteinuria in Chronic Inflammatory Demyelinating Polyneuropathy.

Abstract

There are few case reports of concomitant chronic inflammatory demyelinating polyneuropathy (CIDP) and focal segmental glomerulosclerosis. A rare autoantibody to a neuronal and podocyte structural component, neurofascin, may be contributory. A Black man in his 40s presented with worsening polyneuropathy requiring mechanical ventilation and initially acute inflammatory demyelinating polyneuropathy was diagnosed. After a poor response to intravenous immunoglobulin, plasmapheresis was initiated. The patient also had concomitant new-onset nephrotic-range proteinuria. A limited kidney biopsy was interpreted as minimal change disease and was treated with prednisone. After some improvement, the patient was extubated; however, he later re-presented with worsening symptoms requiring mechanical ventilation and was re-treated with plasmapheresis. Due to the protracted course and poor response to intravenous immunoglobulin, acute-onset CIDP was diagnosed and a neuromuscular antibody workup returned positive for neurofascin, supporting the diagnosis of seropositive acute-onset CIDP. A repeat kidney biopsy demonstrated focal segmental glomerulosclerosis and acute tubular damage. The patient was treated with steroids and tacrolimus and later transitioned to rituximab. Neurofascin enzyme-linked immunosorbent assay then tested negative with concomitant resolution of both neuropathy and proteinuria. Further studies will help validate these findings and the treatment strategy.

• Authors: Syed Bukhari, Margaret Bettin, Helen P Cathro, Kelly Gwathmey, Jitendra Gautam, Brendan Bowman
• Journal: Kidney medicine (Kidney Med) 2020 Nov-Dec Vol. 2 Issue 6 Pg. 797-800 ISSN: 2590-0595 [Electronic] United States
• PMID: 33319203 (Publication Type: Case Reports)
• Copyright: © 2020 Published by Elsevier Inc. on behalf of the National Kidney Foundation, Inc.