The persistence of proteinuria and hematuria after immunosuppressive induction therapy could have prognostic value in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), according to a new study published in Kidney International.
The analysis of a large cohort of 571 patients with AAV identified persistent proteinuria after the induction of
remission as an independent predictor of death or end-stage kidney disease. Moreover, persistent hematuria or proteinuria after induction therapy was an independent predictor of renal relapse.
After induction therapy, 29.8% of patients had persistent hematuria and 34.3% showed increased urine protein/creatinine ratio (0.05 g/mmol or more).
“Precision medicine relying on individual characteristics is currently revolutionizing patient management in many fields of medicine. Awaiting for the development and validation of novel biomarkers, simple, non-invasive and costless assessment of proteinuria and hematuria should be used for management of AAV glomerulonephritis, especially to assess long-term renal prognosis of these patients,” the study’s authors recommended.
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After a median follow-up of 28 months, a urine protein/creatinine ratio of 0.05 g/mmol or more after induction therapy was associated with significant risk of death or kidney failure (adjusted hazard ratio, 3.06; 95% CI, 1.09-8.59) and kidney relapse (adjusted subdistribution HR, 2.22; 95% CI, 1.16-4.24).
These results were obtained after adjusting for age, ANCA type, maintenance therapy, serum creatinine, and persistent hematuria after induction therapy.
Conversely, persistent hematuria after induction therapy was associated with kidney relapse (adjusted subdistribution hazard ratio, 2.16; 95% CI, 1.13-4.11), but not with relapse affecting any organ, kidney failure, or death.
The study included participants from 5 European randomized clinical trials on AAV (MAINRITSAN, MAINRITSAN2, RITUXVAS, MYCYC, and IMPROVE). Most (60%) participants had ANCAs directed against proteinase 3, whereas 35% had ANCAs directed against myeloperoxidase. Also, 77% of patients had kidney involvement.
Benichou N, Charles P, Terrier B, et al. Proteinuria and hematuria after remission induction are associated with outcome in ANCA-associated vasculitis. Kidney Int. Published online March 20, 2023. doi:10.1016/j.kint.2023.02.029