Contactin-1-Associated Membranous Nephropathy after Multiple mRNA 1273 COVID-19 Vaccinations: A Case Report.

Contactin-1-associated membranous nephropathy is a rare type of membranous nephropathy typically seen in the setting of chronic inflammatory demyelinating polyneuropathy. Here we present a case of a 79-year-old man who presented with ankle edema and was found to have 2,888 milligrams of proteinuria per 24 h and membranous nephropathy on kidney biopsy. Staining for multiple membranous antigens including phospholipase A-2 receptor, NELL-1, and EXT-2 were negative. Liquid chromatography tandem mass spectrometry was performed on glomeruli and identified contactin-1 as the target antigen. Classic secondary causes of membranous nephropathy were excluded including systemic autoimmune disease, malignancies, and medications. Interestingly, the membranous nephropathy occurred 1 month after receiving the last of five doses of mRNA COVID 1273 that occurred over a 19-month period. The patient subsequently underwent spontaneous remission without initiation of disease targeted therapy, suggesting a tentative association between the COVID-19 vaccination and the membranous nephropathy. Additionally, this patient did not have any significant neuropathies typically seen with contactin-1-associated membranous nephropathy. To our knowledge, this is the first case report demonstrating a temporal association between contactin-1-associated membranous nephropathy and vaccination against COVID-19 with mRNA 1273. Our findings in this case broaden the clinical spectrum of the rare contactin-1-associated membranous nephropathy.