Contactin-1 links autoimmune neuropathy and membranous glomerulonephritis

Janev Fehmi*, Alexander J. Davies, Marilina Antonelou, Stephen Keddie, Sonja Pikkupeura, Luis Querol, Emilien Delmont, Andrea Cortese, Diego Franciotta, Staffan Persson, Jonathan Barratt, Ruth Pepper, Filipa Farinha, Anisur Rahman, Diana Canetti, Janet A. Gilbertson, Nigel B. Rendell, Aleksandar Radunovic, Thomas Minton, Geraint FullerSinead M. Murphy, Aisling S. Carr, Mary R. Reilly, Filip Eftimov, Luuk Wieske, Charlotte E. Teunissen, Ian S. D. Roberts, Neil Ashman, Alan D. Salama, Simon Rinaldi

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Membranous glomerulonephritis (MGN) is a common cause of nephrotic syndrome in adults, mediated by glomerular antibody deposition to an increasing number of newly recognised antigens. Previous case reports have suggested an association between patients with anti-contactin-1 (CNTN1)-mediated neuropathies and MGN. In an observational study we investigated the pathobiology and extent of this potential cause of MGN by examining the association of antibodies against CNTN1 with the clinical features of a cohort of 468 patients with suspected immune-mediated neuropathies, 295 with idiopathic MGN, and 256 controls. Neuronal and glomerular binding of patient IgG, serum CNTN1 antibody and protein levels, as well as immune-complex deposition were determined. We identified 15 patients with immune-mediated neuropathy and concurrent nephrotic syndrome (biopsy proven MGN in 12/12), and 4 patients with isolated MGN from an idiopathic MGN cohort, all seropositive for IgG4 CNTN1 antibodies. CNTN1-containing immune complexes were found in the renal glomeruli of patients with CNTN1 antibodies, but not in control kidneys. CNTN1 peptides were identified in glomeruli by mass spectroscopy. CNTN1 seropositive patients were largely resistant to first-line neuropathy treatments but achieved a good outcome with escalation therapies. Neurological and renal function improved in parallel with suppressed antibody titres. The reason for isolated MGN without clinical neuropathy is unclear. We show that CNTN1, found in peripheral nerves and kidney glomeruli, is a common target for autoantibody-mediated pathology and may account for between 1 and 2% of idiopathic MGN cases. Greater awareness of this cross-system syndrome should facilitate earlier diagnosis and more timely use of effective treatment.
Original languageEnglish
Article numbere0281156
JournalPLoS ONE
Issue number3 March
Publication statusPublished - 1 Mar 2023

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