Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
Department of Pathology, Medical University of Vienna, Vienna, Austria.
Transplantation. 2020 Jan;104(1):145-153. doi: 10.1097/TP.0000000000002699.
Urological obstructive complications (UOC) affect up to 15% of kidney transplants (KTX). Most cases are excluded by ultrasonography (US); however, accuracy may be limited in the early transplant phase. Features of acute tubular injury (ATI) in KTX biopsy may be informative but histological features indicating UOC are ill defined. Tubular ectasia (TE) was shown to be associated with UOC in experimental data. We evaluated the association of histomorphological features, particularly TE, with occult (=without relevant hydronephrosis in US) UOC and renal outcomes.
We included all recipients with an early indication biopsy (976 of 1537 consecutive KTX). The biopsy finding of TE classified as "suspicious of UOC" was compared with the following endpoints: delayed graft function, estimated glomerular filtration rate, and occult UOC. Additionally, histopathological features of ATI were reevaluated by a single pathologist to increase diagnostic accuracy.
Fifty-eight (5.9%) patients presented with TE, which was not related to delayed graft function or estimated glomerular filtration rate. Forty percent of patients had a UOC (most frequently ureteral stenosis) close to biopsy. Comparing these biopsies to matched controls, TE was significantly associated with UOC (odds ratio 2.69; P = 0.018). After histopathological reevaluation of these biopsies including additional features of ATI, we developed a final multivariate model with a highly significant relationship to UOC (Receiver operating characteristic-area under the curve: 0.77; P = 0.001). The model provides a specificity of 78% and negative predictive value of 73%.
TE together with additional signs of ATI indicates occult UOC. This histological phenotype should trigger more detailed evaluation for UOC when there is no evidence of relevant hydronephrosis in the ultrasonography.
泌尿系统梗阻性并发症（UOC）影响高达 15%的肾移植（KTX）。大多数病例可通过超声检查（US）排除；然而，在移植早期，准确性可能有限。急性肾小管损伤（ATI）的 KTX 活检特征可能具有信息性，但指示 UOC 的组织学特征尚未明确界定。管状扩张（TE）在实验数据中与 UOC 相关。我们评估了组织形态学特征，特别是 TE，与隐匿性（US 无相关肾积水）UOC 和肾脏结局的相关性。
我们纳入了所有早期有指征的活检受者（1537 例连续 KTX 中的 976 例）。将 TE 的活检发现归类为“疑似 UOC”，并与以下终点进行比较：延迟移植物功能、估计肾小球滤过率和隐匿性 UOC。此外，由一位病理学家重新评估 ATI 的组织病理学特征，以提高诊断准确性。
58 例（5.9%）患者出现 TE，与延迟移植物功能或估计肾小球滤过率无关。40%的患者在活检附近存在 UOC（最常见的是输尿管狭窄）。将这些活检与匹配的对照组进行比较，TE 与 UOC 显著相关（优势比 2.69；P = 0.018）。在对这些活检进行包括 ATI 其他特征的组织病理学重新评估后，我们建立了一个与 UOC 高度相关的最终多变量模型（接收者操作特征曲线下面积：0.77；P = 0.001）。该模型的特异性为 78%，阴性预测值为 73%。
TE 加上 ATI 的其他迹象表明存在隐匿性 UOC。当超声检查没有提示相关肾积水时，这种组织学表型应提示更详细地评估 UOC。
