{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T11:49:21Z","timestamp":1762429761868,"version":"build-2065373602"},"reference-count":19,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T00:00:00Z","timestamp":1762387200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated fibroinflammatory condition affecting multiple organs. IgG4-related tubulointerstitial nephritis (IgG4-TIN) is the predominant pattern of kidney involvement. Amyloid A (AA) amyloidosis is a systemic amyloidosis that develops secondary to chronic inflammation or infection, most frequently affecting the kidneys. The association between IgG4-RD and AA amyloidosis is rarely reported. Herein, we report a case of a 56-year-old Chinese man presenting with a one-year history of dizziness and fatigue. The clinical evaluation and laboratory findings showed multiple enlarged lymph nodes, elevated serum creatinine, and increased levels of IgG4 and C-reactive protein. A kidney biopsy revealed IgG4-TIN. Furthermore, patchy congophilic amyloid deposits in the interstitium and arteriolar walls were positive for AA protein by immunohistochemical staining. Subsequent cervical lymph node biopsy showed IgG4-related lymphadenopathy. With prednisone and cyclophosphamide treatment, the patient achieved complete remission of renal function and a noticeable decrease in IgG4 and C-reactive protein levels. This is the first reported case to our knowledge of IgG4-related lymphadenopathy, IgG4-TIN, concurrent with renal AA amyloidosis. Clinicians should be aware that AA amyloidosis may occur in patients with IgG4-TIN, warranting further investigation into the underlying mechanisms linking AA amyloidosis to IgG4-RD.<\/jats:p>","DOI":"10.3389\/fimmu.2025.1672609","type":"journal-article","created":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T11:42:35Z","timestamp":1762429355000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: A rare case of concurrence of IgG4-related tubulointerstitial nephritis and renal Amyloid A amyloidosis"],"prefix":"10.3389","volume":"16","author":[{"given":"Xiaojuan","family":"Zhu","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yueyue","family":"Zhu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shuang","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jin","family":"Xu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Suxia","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,11,6]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-med-050219-034449","article-title":"Clinical perspectives on IgG4-related disease and its classification","volume":"73","author":"Katz","year":"2022","journal-title":"Annu Rev Med"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1038\/modpathol.2012.72","article-title":"Consensus statement on the pathology of IgG4-related disease","volume":"25","author":"Deshpande","year":"2012","journal-title":"Mod Pathol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.2215\/CJN.0000000000000235","article-title":"IgG4-related kidney disease","volume":"18","author":"Peyronel","year":"2023","journal-title":"Clin J Am Soc Nephrol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1007\/s11926-024-01147-8","article-title":"AA amyloidosis: A contemporary view","volume":"26","author":"Mirioglu","year":"2024","journal-title":"Curr Rheumatol Rep"},{"key":"B5","doi-asserted-by":"publisher","first-page":"599","DOI":"10.1056\/NEJMc1614275","article-title":"AA amyloidosis and IgG4-related disease","volume":"376","author":"Karim","year":"2017","journal-title":"N Engl J Med"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/keaa467","article-title":"Amyloid A amyloidosis secondary to immunoglobulin G4-related disease","volume":"60","author":"Wisniowski-Y\u00e1\u00f1ez","year":"2021","journal-title":"Rheumatol (Oxford)"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1007\/s40620-024-01924-9","article-title":"ALECT2 amyloidosis with concurrent IgG4-related interstitial nephritis, membranous nephropathy and diabetic kidney disease: a case report and literature review","volume":"37","author":"Shaheen","year":"2024","journal-title":"J Nephrol"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1080\/14397595.2020.1859710","article-title":"The 2020 revised comprehensive diagnostic (RCD) criteria for IgG4-RD","volume":"31","author":"Umehara","year":"2021","journal-title":"Mod Rheumatol"},{"key":"B9","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1136\/annrheumdis-2019-216561","article-title":"The 2019 American College of Rheumatology\/European League Against Rheumatism classification criteria for IgG4-related disease","volume":"79","author":"Wallace","year":"2020","journal-title":"Ann Rheum Dis"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2018-214603","article-title":"ACR\/EULAR IgG4-RD Classification Criteria Committee. Clinical phenotypes of IgG4-related disease: an analysis of two international cross-sectional cohorts","volume":"78","author":"Wallace","year":"2019","journal-title":"Ann Rheum Dis"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1016\/j.ekir.2024.05.011","article-title":"Clinicopathologic features of IgG4-related kidney disease","volume":"9","author":"Buglioni","year":"2024","journal-title":"Kidney Int Rep"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1002\/art.39205","article-title":"IgG4-related disease: clinical and laboratory features in one hundred twenty-five patients","volume":"67","author":"Wallace","year":"2015","journal-title":"Arthritis Rheumatol"},{"key":"B13","doi-asserted-by":"publisher","first-page":"262","DOI":"10.1186\/s13075-017-1467-x","article-title":"New clues to the nature of immunoglobulin G4-related disease: a retrospective Japanese multicenter study of baseline clinical features of 334 cases","volume":"19","author":"Yamada","year":"2017","journal-title":"Arthritis Res Ther"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1053\/j.semdp.2024.01.003","article-title":"IgG4-related lymphadenopathy","volume":"41","author":"Cheuk","year":"2024","journal-title":"Semin Diagn Pathol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1002\/art.40365","article-title":"Implications of elevated C-reactive protein and serum amyloid A levels in IgG4-related disease: comment on the article by Perugino et\u00a0al","volume":"70","author":"Karim","year":"2018","journal-title":"Arthritis Rheumatol"},{"key":"B16","doi-asserted-by":"publisher","first-page":"106","DOI":"10.1186\/s12969-022-00757-9","article-title":"The relation between C-reactive protein and serum amyloid A in patients with autoinflammatory diseases","volume":"20","author":"Legger","year":"2022","journal-title":"Pediatr Rheumatol Online J"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.55730\/1300-0144.5629","article-title":"Investigation of the value of hematological biomarkers in the clinical differential diagnosis of IgG4-RD","volume":"53","author":"Karadeniz","year":"2023","journal-title":"Turk J Med Sci"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/S2665-9913(23)00299-0","article-title":"Fibrotic phenotype of IgG4-related disease","volume":"6","author":"Lanzillotta","year":"2024","journal-title":"Lancet Rheumatol"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.3389\/fmed.2020.00253","article-title":"Comparison of the effects of cyclophosphamide and mycophenolate mofetil treatment against immunoglobulin G4-related disease: A retrospective cohort study","volume":"7","author":"Luo","year":"2020","journal-title":"Front Med (Lausanne)"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1672609\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T11:42:38Z","timestamp":1762429358000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1672609\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,6]]},"references-count":19,"alternative-id":["10.3389\/fimmu.2025.1672609"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2025.1672609","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,6]]},"article-number":"1672609"}}