{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T14:10:52Z","timestamp":1785420652613,"version":"3.56.0"},"reference-count":11,"publisher":"BMJ","issue":"7","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,7,7]]},"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:p>A woman in her early 50s presented with haemoptysis and cavitary pulmonary nodules. Initial testing showed a low-titre positive cryptococcal antigen (CrAg); however, repeat testing on two occasions was negative. Her cavitary nodules were ultimately attributed to an overlap systemic autoimmune rheumatic disease. She achieved complete clinical and radiological resolution with corticosteroid therapy. This case highlights the importance of recognising false-positive serum CrAg results.<\/jats:p>","DOI":"10.1136\/bcr-2026-274581","type":"journal-article","created":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T13:25:14Z","timestamp":1785417914000},"page":"e274581","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["False-positive cryptococcal antigen in a patient with cavitary pulmonary nodules and haemoptysis"],"prefix":"10.1136","volume":"19","author":[{"given":"Isaac","family":"Bell","sequence":"first","affiliation":[{"name":"Internal Medicine, Florida State University College of Medicine \"FSU\", Tallahassee, Florida, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Winnie","family":"Bell","sequence":"additional","affiliation":[{"name":"Family Medicine Residency Program, US Naval Hospital Jacksonville, Jacksonville, Florida, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hussam","family":"Ammar","sequence":"additional","affiliation":[{"name":"Internal Medicine, Florida State University College of Medicine \"FSU\", Tallahassee, Florida, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Huang","sequence":"additional","affiliation":[{"name":"Tallahassee Memorial HealthCare Inc, Tallahassee, Florida, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,7,30]]},"reference":[{"key":"2026073006250482000_19.7.e274581.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.chest.2018.02.026"},{"key":"2026073006250482000_19.7.e274581.2","doi-asserted-by":"crossref","first-page":"103915","DOI":"10.1016\/j.resmic.2021.103915","article-title":"Fungal infections diagnosis - Past, present and future","volume":"173","author":"Mendon\u00e7a","year":"2022","journal-title":"Res Microbiol"},{"key":"2026073006250482000_19.7.e274581.3","doi-asserted-by":"crossref","first-page":"2307","DOI":"10.1128\/jcm.32.9.2307-2308.1994","article-title":"Effect of potential interference factors on performance of enzyme immunoassay and latex agglutination assay for cryptococcal antigen","volume":"32","author":"Engler","year":"1994","journal-title":"J Clin Microbiol"},{"key":"2026073006250482000_19.7.e274581.4","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(23)00731-4"},{"key":"2026073006250482000_19.7.e274581.5","doi-asserted-by":"crossref","first-page":"1043","DOI":"10.1186\/s12879-021-06752-x","article-title":"Clinical features of cryptococcosis in patients with different immune statuses: a multicenter study in Jiangsu Province\u2013China","volume":"21","author":"Wang","year":"2021","journal-title":"BMC Infect Dis"},{"key":"2026073006250482000_19.7.e274581.6","doi-asserted-by":"crossref","first-page":"1623","DOI":"10.1148\/radiographics.20.6.g00nv031623","article-title":"Thoracic manifestations of systemic autoimmune diseases: radiographic and high-resolution CT findings","volume":"20","author":"Mayberry","year":"2000","journal-title":"Radiographics"},{"key":"2026073006250482000_19.7.e274581.7","doi-asserted-by":"crossref","DOI":"10.1259\/bjr.20150992","article-title":"The lung in systemic vasculitis: radiological patterns and differential diagnosis","volume":"89","author":"Feragalli","year":"2016","journal-title":"Br J Radiol"},{"key":"2026073006250482000_19.7.e274581.8","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.00751-17"},{"key":"2026073006250482000_19.7.e274581.9","doi-asserted-by":"publisher","DOI":"10.1093\/ajcp\/58.5.358"},{"key":"2026073006250482000_19.7.e274581.10","doi-asserted-by":"crossref","first-page":"700","DOI":"10.1128\/jcm.14.6.700-702.1981","article-title":"Serum cryptococcal antigen determination in the presence of rheumatoid factor","volume":"14","author":"Eng","year":"1981","journal-title":"J Clin Microbiol"},{"key":"2026073006250482000_19.7.e274581.11","doi-asserted-by":"publisher","DOI":"10.1007\/s15010-016-0909-8"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2026-274581","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T13:25:15Z","timestamp":1785417915000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2026-274581"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7]]},"references-count":11,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7,30]]},"published-print":{"date-parts":[[2026,7]]}},"alternative-id":["10.1136\/bcr-2026-274581"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2026-274581","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7]]}}}