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.
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.