Unit of Urology, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Urological Research Institute (URI), Division of Experimental Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy.
J Nephrol. 2021 Jun;34(3):699-707. doi: 10.1007/s40620-020-00905-y. Epub 2021 Jan 4.
The chronic kidney disease (CKD) classification represents a simple tool to evaluate kidney disease. However, it is not based on kidney histology and this might limit the correlation between renal function and histological damage. The aim of this study was to examine the presence and magnitude of the discordance between CKD classification and kidney histology.
We retrospectively analyzed kidney parenchyma histology in a cohort of 200 patients who underwent radical nephrectomy for a kidney mass to observe its correlation with CKD classification. Kidney tissue of the unaffected part of the removed kidney was analyzed and classified with a chronicity score as described by Sethi et al. Then, all patients were classified according to the respective CKD stage using different equations: CKD-EPI, MDRD, FAS and MCQ.
Median age was 67 (57-75). Diabetes, hypertension and overweight were observed in 23%, 60% and 61%, respectively. The CKD-EPI equation stratified 30.5% (n = 61) of the subjects into CKD stage 1, 41.5% (n = 83) into CKD stage 2, 25.5% into CKD stage 3 (n = 51) and 2.5% into CKD stage 4-5 (n = 5). About 30-40% of the patients with CKD stage 3 had mild or no lesions in the histological evaluation (Chronicity Score = 0-1), whereas 7-10% of those with CKD stage 1 had moderate or severe histological lesions (Chronicity Score ≥ 3). Different patients with the same value of estimated glomerular filtration rate (eGFR) had either severe or no histological damage.
The variability of kidney histology observed within each CKD stage is not negligible. This may limit the reliability of the current CKD classification. More research is needed to clarify the relationship between CKD stages and kidney damage.
慢性肾脏病（CKD）分类是评估肾脏疾病的一种简单工具。然而，它并非基于肾脏组织学，这可能限制了肾功能与组织学损伤之间的相关性。本研究旨在探讨 CKD 分类与肾脏组织学之间存在差异的程度和性质。
我们回顾性分析了 200 例因肾脏肿块接受根治性肾切除术的患者的肾脏实质组织学，观察其与 CKD 分类的相关性。分析并根据 Sethi 等人描述的慢性评分对切除肾脏的未受影响部分的组织进行分类。然后，使用不同的方程（CKD-EPI、MDRD、FAS 和 MCQ）根据各自的 CKD 分期对所有患者进行分类。
中位年龄为 67（57-75）岁。分别有 23%、60%和 61%的患者患有糖尿病、高血压和超重。CKD-EPI 方程将 30.5%（n=61）的受试者分为 CKD 1 期，41.5%（n=83）为 CKD 2 期，25.5%为 CKD 3 期（n=51），2.5%为 CKD 4-5 期（n=5）。大约 30-40%的 CKD 3 期患者在组织学评估中存在轻度或无病变（慢性评分=0-1），而 7-10%的 CKD 1 期患者存在中度或重度组织学病变（慢性评分≥3）。不同肾小球滤过率（eGFR）估计值相同的患者，其组织学损伤程度也不同。
在每个 CKD 分期内观察到的肾脏组织学的变异性不可忽视。这可能会限制当前 CKD 分类的可靠性。需要进一步研究以阐明 CKD 分期与肾脏损伤之间的关系。
