LAUSR

INTRODUCTION Clinical presentation and course of Immunoglobulin A nephropathy vary by ethnicity and geography and significance of extracapillary proliferation or crescents (IgAN-C) in Southeast Asia is not well described. We aimed to describe the clinical course of IgAN-C in Singapore. METHODS Retrospective cohort study of adult biopsy-proven IgAN diagnosed between February 2011 and October 2016 in 2 hospital-based nephrology units. Outcome was chronic kidney disease (CKD) progression, defined as reduction in eGFR ≥50% or end stage renal failure (ESRF). RESULTS 145 patients were studied. Among individuals with IgAN-C (n = 44, 30%), 38 patients had cellular or fibrocellular crescents in 1-25% of the glomeruli and 6 had crescents in >25%. Median eGFR was 54 (33, 83) ml/min/1.73 m2 . Compared to IgAN without crescents, IgAN-C had greater proteinuria [median 2.9 (1.4, 5.4) g/g vs 1.9 (1.1, 3.6) g/g, P = 0.03] and more had endocapillary hypercellularity (96% vs 39%, P < 0.001). IgAN-C were also more likely to receive immunosuppressants (66% vs 43%, P = 0.01) such as prednisolone (63% vs 38%, P = 0.006) and cyclophosphamide (12% vs 2%, P = 0.03). Median follow up was 27 (12, 46) months. IgAN-C were more likely to achieve proteinuria reduction ≥50% at 6 months (66% vs 44%, P = 0.03). CKD progression within 12 months was not different among those with and without crescents (13% vs 10% respectively, P = 0.73). However, immunosuppressant treatment of IgAN-C was associated with reduced ESRF (0 vs 20%, P = 0.03). CONCLUSION immunosuppressants may attenuate the risk of ESRF in IgAN-C. This article is protected by copyright. All rights reserved.