Abstract

The mean of GFR-estimates based on serum creatinine (eGFR_crea) and cystatin C (eGFR_cys) has superior accuracy than each estimate alone. Recent studies have shown that agreement between eGFR_crea and eGFR_cys is an indicator for the accuracy of the mean of the two estimates. As long as the difference between the two (|ΔeGFR|) is below 40%, a high P₃₀ accuracy rate of more than 90% was documented in research settings using gold-standard GFR measurements. This was the case in approximately 80% of the measurements. The study was set out to explore |ΔeGFR| in a broader pediatric nephrological population and identify factors influencing the discrepancy between eGFR_crea and eGFR_cys. We retrospectively analyzed 1596 simultaneous cystatin C and creatinine measurements in 649 unique patients at the pediatric nephrology outpatient clinic of VU university medical center. The FASage equation was used to calculate eGFR_crea, FAScys for eGFR_cys. |ΔeGFR| was calculated as 100x(|eGFR_crea-eGFR_cys|)/(0.5x(eGFR_crea+eGFR_cys). ΔeGFR below 40% was considered high agreement. Patient characteristics like age, diagnosis, glucocorticosteroid use, eGFR, BMI and sex were analyzed for their effect on ΔeGFR below or above 40% using non-parametric tests and a potential explanation for measurements with low agreement was sought. Eighty-seven percent of the population had a |ΔeGFR| lower than 40%. Measurements with |ΔeGFR| above 40% were significantly more frequent from patients with neural tube defects. In 102 out of 208 measurements with low agreement, a potential explanation was found. In a broad pediatric nephrological population, |ΔeGFR| is below 40% in the vast majority of measurements. In this group, the mean of eGFR_crea and eGFR_cys can be used as an accurate estimate of GFR.

摘要

基于血清肌酐 (eGFR _crea ) 和胱抑素 C (eGFR _cys )的 GFR 估计平均值比单独的每个估计具有更高的准确性。最近的研究表明，eGFR _crea和 eGFR _cys之间的_一致性是两个估计值平均值准确性的指标。只要两者之间的差异 (|ΔeGFR|) 低于 40%，就可以在使用黄金标准 GFR 测量的研究环境中记录超过 90%的高 P ₃₀准确率。大约 80% 的测量都是这种情况。该研究旨在探索 | Δ eGFR| 在更广泛的儿科肾脏_病人群中确定影响 eGFR _crea差异的因素和 eGFR _cys。我们回顾性分析了 VU 大学医学中心儿科肾脏病门诊的 649 名独特患者的 1596 项同时进行的胱抑素 C 和肌酐测量值。该FASage方程来计算肾小球滤过_CREA，FAScys EGFR的_半胱氨酸。|ΔeGFR| 计算为 100x(|eGFR _crea -eGFR _cys |)/(0.5x(eGFR _crea +eGFR _cys）。低于 40% 的 ΔeGFR 被认为是高度一致的。使用非参数检验分析了年龄、诊断、糖皮质激素使用、eGFR、BMI 和性别等患者特征对低于或高于 40% 的 ΔeGFR 的影响，并寻求对低一致性测量值的潜在解释。87% 的人口有 |ΔeGFR| 低于 40%。使用 |ΔeGFR| 进行测量 神经管缺陷患者的发病率明显高于 40%。在 208 次低一致性测量中的 102 次中，找到了可能的解释。在广泛的儿科肾病人群中，|ΔeGFR| 在绝大多数测量中低于 40%。在该组中，eGFR _crea和 eGFR _cys的平均值可用作 GFR 的准确估计。