PT  - JOURNAL ARTICLE
AU  - Aendekerk, Joop P.
AU  - Timmermans, Sjoerd A.M.E.G.
AU  - Busch, Matthias H.
AU  - Potjewijd, Judith
AU  - Heeringa, Peter
AU  - Damoiseaux, Jan G.M.C.
AU  - Reutelingsperger, Chris P.
AU  - van Paassen, Pieter
AU  - , 
TI  - Urinary Soluble CD163 and Disease Activity in Biopsy-Proven ANCA-Associated Glomerulonephritis
AID  - 10.2215/CJN.07210520
DP  - 2020 Nov 17
TA  - Clinical Journal of the American Society of Nephrology
PG  - CJN.07210520
4099  - http://cjasn.asnjournals.org/content/early/2020/11/17/CJN.07210520.short
4100  - http://cjasn.asnjournals.org/content/early/2020/11/17/CJN.07210520.full
AB  - Background and objectives ANCA-associated GN is a common cause of rapidly progressive GN, with high relapse rates. The early recognition of an ANCA-associated GN relapse is of importance to prevent loss of kidney function. Urinary soluble CD163 has been identified as a promising marker of active ANCA-associated GN. Previous studies, however, are limited by the lack of histologic data.Design, setting, participants, & measurements We analyzed urinary soluble CD163 in 95 patients with ANCA-associated vasculitis who underwent a kidney biopsy. In total, 125 kidney tissue sections (first kidney biopsy, n=67; repeated biopsy, n=58) with concurrent 24-hour urine samples were studied. Correlation analyses comparing urinary soluble CD163 levels and morphologic features of ANCA-associated GN were performed using Spearman rank correlation analysis. The diagnostic performance of biomarkers to detect relapsing ANCA-associated GN was evaluated using receiver operating characteristics curve analysis.Results High levels of urinary soluble CD163 were found in 96 (87%) of 110 biopsies with active ANCA-associated GN compared with one (7%) of 15 biopsies without active ANCA-associated GN and one (6%) of 17 healthy controls. Urinary soluble CD163 correlated with fibrinoid necrosis (Rho=0.48, P<0.001) and cellular crescents (Rho=0.70, P<0.001) on kidney biopsy. In repeated biopsies, urinary soluble CD163’s sensitivity of 0.94 and specificity of 0.91 for the recognition of relapsing ANCA-associated GN appeared better than routine clinical measures. The presence of CD163+ cells in affected glomeruli confirmed urinary soluble CD163’s origin.Conclusions Urinary soluble CD163 is associated with active ANCA-associated GN and correlates with histologic features as seen in ANCA-associated GN.Podcast This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_11_17_CJN07210520_final.mp3