Background Renal involvement in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is associated with poor outcomes. The clinical significance of arteritis of the small kidney arteries has not been evaluated in detail. Methods In a multicenter cohort of AAV patients with renal involvement, we sought to describe the clinicopathologic characteristics of patients with AAV who had renal arteritis at diagnosis and to retrospectively analyze their prognostic value. Results We included 251 patients diagnosed with AAV and renal involvement between 2000 and 2019, including 34 patients (13.5%) with arteritis. Patients with AAV-associated arteritis were older and had a more pronounced inflammatory syndrome compared with patients without arteritis; they also had significantly lower renal survival (P=0.01). In multivariable analysis, the ANCA renal risk score, age at diagnosis, prior history of diabetes mellitus, and arteritis on index kidney biopsy were independently associated with end-stage renal disease. The addition of the arteritis status significantly improved the discrimination of the ANCA renal risk score, with a concordance index (C-index) of 0.77 for the ANCA renal risk score alone versus a C-index of 0.80 for the ANCA renal risk score plus arteritis status (P=0.008); ESRD-free survival was significantly worse for patients with an arteritis involving small arteries who were classified as having low or moderate risk according to the ANCA renal risk score. In two external validation cohorts, we confirmed the incidence and phenotype of this AAV subtype. Conclusions Our findings suggest that AAV with renal arteritis represents a different subtype of AAV with specific clinical and histologic characteristics. The prognostic contribution of the arteritis status remains to be prospectively confirmed.
[1]
L. Mouthon,et al.
Microscopic polyangiitis: Clinical characteristics and long-term outcomes of 378 patients from the French Vasculitis Study Group Registry.
,
2020,
Journal of autoimmunity.
[2]
J. Mejía-Vilet,et al.
Validation of a renal risk score in a cohort of ANCA-associated vasculitis patients with severe kidney damage
,
2020,
Clinical Rheumatology.
[3]
M. Copin,et al.
Tubulointerstitial damage and interstitial immune cell phenotypes are useful predictors for renal survival and relapse in antineutrophil cytoplasmic antibody-associated vasculitis
,
2020,
Journal of Nephrology.
[4]
P. Merkel,et al.
ANCA-associated vasculitis
,
2020,
Nature Reviews Disease Primers.
[5]
H. Denley,et al.
ANCA renal risk score predicts outcome in the Manchester cohort.
,
2019,
Kidney international.
[6]
I. Mitroulis,et al.
NETopathies? Unraveling the Dark Side of Old Diseases through Neutrophils
,
2017,
Front. Immunol..