The pediatric International IgA Nephropathy (IgAN) Prediction Tool comprises two models with and without ethnicity and is the first method to predict the risk of a 30% decline in estimated glomerular filtration rate (eGFR) or kidney failure in children at the time of biopsy using clinical risk factors and Oxford MEST histology scores. However, it is unknown if the Prediction Tool can be applied after a period of observation post-biopsy. Using an international multi-ethnic cohort of 947 children with IgAN, 38% of whom were followed into adulthood, the Prediction Tool was updated for use one year after biopsy. Compared to the original pediatric Prediction Tool, the updated post-biopsy Prediction Tool had a better model fit with higher R2D (51%/50% vs 20%), significant increase in 4-year C-statistics (0.83 vs 0.73/0.69, ΔC 0.09 [95% confidence interval 0.07-0.10] and ΔC 0.14 [0.12-0.15]) and better 4-year calibration with lower integrated calibration indices (0.74/0.54 vs 2.45/1.01). Results were similar after internal validation and when the models were applied two years after biopsy. Trajectories of eGFR after a baseline one year post-biopsy were non-linear and those at higher predicted risk started with a lower eGFR and experienced a more rapid decline over time. In children, eGFR had a variable rate of increase until 15-18 years old and then decreased linearly with a more rapid decline in higher risk groups that was similar to young adults of comparable risk. Thus, the original pediatric Prediction Tool should be used in children at the time of biopsy, and the updated pediatric Prediction Tool should be used to re-evaluate risk one or two years after biopsy.

中文翻译：

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更新的国际 IgA 肾病预测工具在活检后 1 年或 2 年儿童中的应用


儿科国际 IgA 肾病 （IgAN） 预测工具包括两种模型，有种族和无种族，是第一种使用临床危险因素和牛津 MEST 组织学评分预测儿童活检时估计肾小球滤过率 （eGFR） 下降 30% 或肾功能衰竭风险的方法。但是，目前尚不清楚预测工具是否可以在活检后观察一段时间后应用。使用由 947 名 IgAN 儿童组成的国际多种族队列，其中 38% 的儿童被随访至成年，预测工具在活检后一年更新使用。与原来的儿科预测工具相比，更新后的活检后预测工具具有更好的模型拟合度，R2D 更高 （51%/50% vs 20%），4 年 C 统计量显着增加 （0.83 vs 0.73/0.69，ΔC 0.09 [95% 置信区间 0.07-0.10] 和 ΔC 0.14 [0.12-0.15]） 和更好的 4 年校准，积分校准指数较低 （0.74/0.54 vs 2.45/1.01）。内部验证后和活检后两年应用模型时的结果相似。活检后 1 年基线后 eGFR 的轨迹是非线性的，预测风险较高的人从 eGFR 较低开始，并随着时间的推移下降得更快。在儿童中，eGFR 在 15-18 岁之前呈可变的增加率，然后线性下降，在高风险群体中下降得更快，这与具有相当风险的年轻人相似。因此，在活检时，应在儿童中使用原始的儿科预测工具，并在活检后一两年使用更新的儿科预测工具重新评估风险。