RT Journal Article SR Electronic T1 Fibrillary glomerulonephritis in a patient with systemic lupus erythematosus with no evidence of lupus nephritis JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e253388 DO 10.1136/bcr-2022-253388 VO 16 IS 2 A1 Whelband, Matthew Carl A1 Willingham, Tom A1 Thirunavukkarasu, Sathiamalar A1 Patrick, Jean YR 2023 UL http://casereports.bmj.com/content/16/2/e253388.abstract AB Fibrillary glomerulonephritis (FGN) is a rare proliferative form of glomerular disease characterised by randomly oriented fibrillary deposits with a mean diameter of 20 nm. It has a rare association with systemic lupus erythematosus (SLE). We report the case of a female in her mid-50's with a 20 year history of SLE, who developed proteinuria due to FGN and had no histological evidence of lupus nephritis. She was maintained on azathioprine and prednisolone. A renal biopsy revealed randomly arranged fibrillary deposits that positively stained for DNAJB9, consistent with a diagnosis of FGN. Azathioprine was switched to mycophenolate mofetil, and the patient showed significant improvement in proteinuria. This case-based review describes the diagnosis, management and clinical outcome of FGN in association with SLE in the absence of lupus nephritis.