{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T16:01:40Z","timestamp":1772035300800,"version":"3.50.1"},"reference-count":8,"publisher":"BMJ","issue":"2","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,2,11]]},"published-print":{"date-parts":[[2026,2]]},"abstract":"<jats:p>A woman in her 20s with a mechanical mitral valve replacement on long-term warfarin therapy presented with frank haematuria and acute kidney injury (AKI). The initial clinical impression was anticoagulant-related nephropathy. However, due to the persistence of urinary abnormalities, further evaluation was undertaken. Renal biopsy revealed immunoglobulin A nephropathy with lambda light chain predominance, raising concern for an underlying monoclonal gammopathy. The patient was managed conservatively with antiproteinuric therapy alone, without immunosuppression, and demonstrated favourable renal recovery. This case highlights the diagnostic importance of renal biopsy and thorough clinical reassessment in patients with haematuria and AKI, particularly in the context of anticoagulation.<\/jats:p>","DOI":"10.1136\/bcr-2025-268864","type":"journal-article","created":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T14:55:28Z","timestamp":1772031328000},"page":"e268864","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["When haematuria is more than warfarin: lambda-predominant IgA nephropathy"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-9140-7913","authenticated-orcid":false,"given":"Benny Chia Wue","family":"Lim","sequence":"first","affiliation":[{"name":"Department of Nephrology, Hospital Sultan Idris Shah, Serdang, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fauzah Binti","family":"Abd Ghani","sequence":"additional","affiliation":[{"name":"Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fuah Kar","family":"Wah","sequence":"additional","affiliation":[{"name":"Department of Nephrology, Hospital Sultan Idris Shah, Serdang, Malaysia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3623-0484","authenticated-orcid":false,"given":"Christopher Thiam Seong","family":"Lim","sequence":"additional","affiliation":[{"name":"Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, 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