{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,20]],"date-time":"2026-10-20T15:11:42Z","timestamp":1792509102583,"version":"4.5.0"},"reference-count":37,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"2","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":["JASN"],"published-print":{"date-parts":[[2021,2]]},"abstract":"<jats:p>Membranous nephropathy (MN) occurs due to deposition of immune complexes along the subepithelial region of glomerular basement membrane. Two previously identified target antigens for the immune complexes, PLA2R (identified in 2009) and THSD7A (in 2014), account for approximately 60% of all MN, both primary and secondary. In the remaining MN, target antigens were unknown. Use of laser microdissection and mass spectrometry enabled identification of new \u201cantigens.\u201d This approach led to the identification of four novel types of MN: exotosin 1 (EXT1)\u2013 and exotosin 2 (EXT2)\u2013associated MN, NELL1-associated MN, Sema3B-associated MN, and PCDH7-associated MN. Each of these represents a distinct disease entity, with different clinical and pathologic findings. In this review, the structure of the proteins and the clinical and pathologic findings of the new types of MN are discussed. The role of mass spectrometry for accurate diagnosis of MN cannot be overemphasized. Finally, any classification of MN should be made on the basis of the antigens that are detected. Further studies are required to understand the pathophysiology, response to treatment, and outcomes of these new MNs.<\/jats:p>","DOI":"10.1681\/asn.2020071082","type":"journal-article","created":{"date-parts":[[2020,12,30]],"date-time":"2020-12-30T12:06:50Z","timestamp":1609330010000},"page":"268-278","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":217,"title":["New \u2018Antigens\u2019 in Membranous Nephropathy"],"prefix":"10.1681","volume":"32","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4536-7709","authenticated-orcid":false,"given":"Sanjeev","family":"Sethi","sequence":"first","affiliation":[{"name":"Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2020,12,30]]},"reference":[{"key":"B1-20240826","doi-asserted-by":"crossref","first-page":"660","DOI":"10.3181\/00379727-100-24736","article-title":"Production of nephrotic syndrome in rats by Freund\u2019s adjuvants and rat kidney suspensions","volume":"100","author":"Heymann","year":"1959","journal-title":"Proc Soc Exp Biol Med"},{"key":"B2-20240826","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1056\/NEJMoa0810457","article-title":"M-type phospholipase A2 receptor as target antigen in idiopathic membranous nephropathy","volume":"361","author":"Beck","year":"2009","journal-title":"N Engl J Med"},{"key":"B3-20240826","doi-asserted-by":"crossref","first-page":"2277","DOI":"10.1056\/NEJMoa1409354","article-title":"Thrombospondin type-1 domain-containing 7A in idiopathic membranous nephropathy","volume":"371","author":"Tomas","year":"2014","journal-title":"N Engl J Med"},{"key":"B4-20240826","doi-asserted-by":"crossref","first-page":"983","DOI":"10.2215\/CJN.11761116","article-title":"Primary membranous nephropathy","volume":"12","author":"Couser","year":"2017","journal-title":"Clin J Am Soc Nephrol"},{"key":"B5-20240826","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1007\/s40620-017-0426-6","article-title":"Pathology and diagnosis of renal non-AL amyloidosis","volume":"31","author":"Sethi","year":"2018","journal-title":"J Nephrol"},{"key":"B6-20240826","doi-asserted-by":"crossref","first-page":"1123","DOI":"10.1681\/ASN.2018080852","article-title":"Exostosin 1\/exostosin 2-associated membranous nephropathy","volume":"30","author":"Sethi","year":"2019","journal-title":"J Am Soc Nephrol"},{"key":"B7-20240826","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.kint.2019.09.014","article-title":"Neural epidermal growth factor-like 1 protein (NELL-1) associated membranous nephropathy","volume":"97","author":"Sethi","year":"2020","journal-title":"Kidney Int"},{"key":"B8-20240826","doi-asserted-by":"crossref","first-page":"1253","DOI":"10.1016\/j.kint.2020.05.030","article-title":"Semaphorin 3B-associated membranous nephropathy is a distinct type of disease predominantly present in pediatric patients","volume":"98","author":"Sethi","year":"2020","journal-title":"Kidney Int"},{"key":"B11-20240826","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.matbio.2013.10.001","article-title":"The exostosin family: Proteins with many functions","volume":"35","author":"Busse-Wicher","year":"2014","journal-title":"Matrix Biol"},{"key":"B12-20240826","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1038\/ng1095-137","article-title":"Cloning of the putative tumour suppressor gene for hereditary multiple exostoses (EXT1)","volume":"11","author":"Ahn","year":"1995","journal-title":"Nat Genet"},{"key":"B13-20240826","doi-asserted-by":"crossref","first-page":"511","DOI":"10.1172\/JCI13737","article-title":"The link between heparan sulfate and hereditary bone disease: Finding a function for the EXT family of putative tumor suppressor proteins","volume":"108","author":"Duncan","year":"2001","journal-title":"J Clin Invest"},{"key":"B14-20240826","doi-asserted-by":"crossref","first-page":"668","DOI":"10.1073\/pnas.97.2.668","article-title":"The putative tumor suppressors EXT1 and EXT2 form a stable complex that accumulates in the Golgi apparatus and catalyzes the synthesis of heparan sulfate","volume":"97","author":"McCormick","year":"2000","journal-title":"Proc Natl Acad Sci U S A"},{"key":"B15-20240826","doi-asserted-by":"crossref","first-page":"17615","DOI":"10.1016\/S0021-9258(19)84610-0","article-title":"Glycosyltransferases. 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