Validation of two IgA nephropathy risk-prediction tools using a cohort with a long follow-up

Abstract

Background Recently, two immunoglobulin A nephropathy prediction tools were developed that combine clinical and histopathological parameters. The International IgAN Prediction Tool predicts the risk for 50% declines in the estimated glomerular filtration rate or end-stage renal disease up to 80 months after diagnosis. The IgA Nephropathy Clinical Decision Support System uses artificial neural networks to estimate the risk for end-stage renal disease. We aimed to externally validate both prediction tools using a Norwegian cohort with a long-term follow-up. Methods We included 306 patients with biopsy-proven primary immunoglobulin A nephropathy in this study. Histopathologic samples were retrieved from the Norwegian Kidney Biopsy Registry and reclassified according to the Oxford classification. We used discrimination and calibration as principles for externally validating the prognostic models. Results The median patient follow-up was 17.1 years. A cumulative dynamic time-dependent receiver operating characteristic analysis showed area under the curve values of ranging from 0.90 at 5 years to 0.83 at 20 years for the International IgAN Prediction Tool, while time-naive analysis showed an area under the curve value at 0.83 for the IgA Nephropathy Clinical Decision Support System. The International IgAN Prediction Tool was well calibrated, while the IgA Nephropathy Clinical Decision Support System tends to underestimate risk for patients with higher risk, and overestimates risk in the lower risk categories. Conclusions We have externally validated two prediction tools for IgA nephropathy. The International IgAN Prediction Tool performed well, while the IgA Nephropathy Clinical Decision Support System has some limitations.

Noninvasive Assessment of the Renal Function, Oxford Classification and Prognostic Risk Stratification of IgAN by Using Intravoxel Incoherent Motion Diffusion‐Weighted Imaging and Blood Oxygenation Level‐Dependent MRI

“…Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, and approximately 20%–40% of affected patients develop end‐stage kidney disease (ESKD) within 10–20 years after diagnosis 1 . The clinical presentations are highly variable, ranging from solitary hematuria to rapid progression to renal failure, 2 and various histological pathologies have been described, ranging from mild mesangial cell proliferation to crescentic glomerulonephritis and diffuse sclerosis 3 . The guidelines recommend risk stratification for each patient so that high‐risk patients who are most likely to benefit can be treated 4 .…”

Use of corticosteroids in Norwegian patients with immunoglobulin a nephropathy progressing to end-stage kidney disease: a retrospective cohort study

“…Corticosteroids were initiated when the patients had a median eGFR of 21 mL/min/1.73 m 2 , which is lower than the recommendations in the clinical guidelines [ 8 ]. This may indicate that Norwegian nephrologists are restrictive when it comes to corticosteroid therapy, as previously noted [ 33 ]. In the VALIGA cohort, patients from Northern Europe had significantly worse kidney outcomes ( p < 0.001) than patients from Southern Europe despite similarities in clinical baseline data [ 32 ].…”

Evaluation of the clinical value of 10 estimating glomerular filtration rate equations and construction of a prediction model for kidney damage in adults from central China

“…In 2022, the validation of the international IgA nephropathy risk prediction tool was performed through a study in Norway involving 306 IgA nephropathy patients diagnosed by renal biopsy pathology (with a median follow-up of 17.1 years). The results indicated that the international IgAN prediction tool sometimes outperformed the clinical decision support system for IgA nephropathy ( Haaskjold et al, 2023 ). These prediction models can effectively assess the risk of kidney injury following various types of organ damage ( Ravizza et al, 2019 ; Bjork et al, 2020 ; Wu et al, 2023 ), and predict the risk of functional impairment in other organs following kidney damage ( Meyer et al, 2018 ).…”