Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota.
Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
Am J Kidney Dis. 2024 Jul;84(1):62-72.e1. doi: 10.1053/j.ajkd.2023.11.016. Epub 2024 Jan 26.
RATIONALE & OBJECTIVE: Simple kidney cysts, which are common and usually considered of limited clinical relevance, are associated with older age and lower glomerular filtration rate (GFR), but little has been known of their association with progressive chronic kidney disease (CKD).
Observational cohort study.
SETTING & PARTICIPANTS: Patients with presurgical computed tomography or magnetic resonance imaging who underwent a radical nephrectomy for a tumor; we reviewed the retained kidney images to characterize parenchymal cysts at least 5mm in diameter according to size and location.
Parenchymal cysts at least 5mm in diameter in the retained kidney. Cyst characteristics were correlated with microstructural findings on kidney histology.
Progressive CKD defined by dialysis, kidney transplantation, a sustained≥40% decline in eGFR for at least 3 months, or an eGFR<10mL/min/1.73m that was at least 5mL/min/1.73m below the postnephrectomy baseline for at least 3 months.
Cox models assessed the risk of progressive CKD. Models adjusted for baseline age, sex, body mass index, hypertension, diabetes, eGFR, proteinuria, and tumor volume. Nonparametric Spearman's correlations were used to examine the association of the number and size of the cysts with clinical characteristics, kidney function, and kidney volumes.
There were 1,195 patients with 50 progressive CKD events over a median 4.4 years of follow-up evaluation. On baseline imaging, 38% had at least 1 cyst, 34% had at least 1 cortical cyst, and 8.7% had at least 1 medullary cyst. A higher number of cysts was associated with progressive CKD and was modestly correlated with larger nephrons and more nephrosclerosis on kidney histology. The number of medullary cysts was more strongly associated with progressive CKD than the number of cortical cysts.
Patients who undergo a radical nephrectomy may differ from the general population. A radical nephrectomy may accelerate the risk of progressive CKD. Genetic testing was not performed.
Cysts in the kidney, particularly the medulla, should be further examined as a potentially useful imaging biomarker of progressive CKD beyond the current clinical evaluation of kidney function and common CKD risk factors.
PLAIN-LANGUAGE SUMMARY: Kidney cysts are common and often are considered of limited clinical relevance despite being associated with lower glomerular filtration rate. We studied a large cohort of patients who had a kidney removed due to a tumor to determine whether cysts in the retained kidney were associated with kidney health in the future. We found that more cysts in the kidney and, in particular, cysts in the deepest tissue of the kidney (the medulla) were associated with progressive kidney disease, including kidney failure where dialysis or a kidney transplantation is needed. Patients with cysts in the kidney medulla may benefit from closer monitoring.
单纯性肾囊肿较为常见且通常认为具有有限的临床意义，其与年龄较大和肾小球滤过率（GFR）较低相关，但人们对其与慢性肾脏病（CKD）的进展之间的关系知之甚少。
观察性队列研究。
接受根治性肾切除术治疗肿瘤的患者，术前进行计算机断层扫描或磁共振成像检查；我们回顾保留肾脏的图像，根据大小和位置对至少 5mm 直径的实质囊肿进行特征描述。
保留肾脏中至少 5mm 直径的实质囊肿。囊肿特征与肾脏组织学的微观结构发现相关联。
定义为透析、肾移植、eGFR 持续下降≥40%至少 3 个月，或 eGFR<10mL/min/1.73m，且至少 5mL/min/1.73m 低于至少 3 个月的肾切除术后基线。
Cox 模型评估进展性 CKD 的风险。模型调整了基线年龄、性别、体重指数、高血压、糖尿病、eGFR、蛋白尿和肿瘤体积。非参数 Spearman 相关用于检查囊肿数量和大小与临床特征、肾功能和肾脏体积之间的关联。
在中位随访 4.4 年的评估中，有 1195 例患者发生了 50 例进展性 CKD 事件。基线影像学检查显示，38%的患者至少有 1 个囊肿，34%的患者至少有 1 个皮质囊肿，8.7%的患者至少有 1 个髓质囊肿。囊肿数量与进展性 CKD 相关，与肾脏组织学上较大的肾单位和更多的肾硬化症呈中度相关。髓质囊肿数量与皮质囊肿数量相比，与进展性 CKD 的相关性更强。
接受根治性肾切除术的患者可能与一般人群不同。根治性肾切除术可能会加速进展性 CKD 的风险。未进行基因检测。
肾脏中的囊肿，特别是髓质中的囊肿，应该作为一种潜在有用的成像生物标志物，在目前对肾功能和常见 CKD 危险因素的临床评估之外，进一步检查其与进展性 CKD 的关系。
