Mendelson Lisa, Sanchorawala Vaishali, Connors Lawreen, Joshi Tracy, Doros Gheorghe, Pogrebinsky Alexander, Havasi Andrea
Amyloidosis Center, Boston University School of Medicine, Boston, Massachusetts.
Section of Hematology and Oncology, Department of Medicine, Boston Medical Center, Boston, Massachusetts.
Kidney Med. 2022 Feb 3;4(4):100427. doi: 10.1016/j.xkme.2022.100427. eCollection 2022 Apr.
RATIONALE & OBJECTIVE: Test the feasibility of replacing 24-hour urine collection with a single voided urinary protein-creatinine ratio (UPCR) in patients with amyloid light-chain (AL) amyloidosis.
Retrospective study examining the correlation between a 24-hour urine measurement and UPCR at various proteinuria levels using a linear regression analysis with Pearson's correlation coefficient (r). We assessed how using these 2 different measurements would alter the diagnosis, staging, and kidney response assessment in patients with AL amyloidosis.
SETTING & PARTICIPANTS: We included 265 patients with systemic AL amyloidosis who visited the Amyloidosis Center at Boston University between July 2018-January 2020 and had proteinuria measurement by both methods on the same day.
24-hour urine collection for protein versus UPCR.
The correlation between 24-hour urine and UPCR was moderate in patients with proteinuria levels of 500-3,000 mg/day and >3,000 mg/day, with r values of 0.57 and 0.62, respectively. Replacing the 24-hour urine collection with UPCR changed kidney staging in 10% of the patients: 77% were reclassified to a worse kidney stage and 23% to a more favorable stage. The majority of changes (85%) in kidney staging occurred in the >3,000 mg/day cohort. There were 35 patients whose kidney response was assessed by concomitant 24-hour urine collection and UPCR with visits at least 6 months apart. Of these patients, 20% had discordance between the 24-hour urine collection and UPCR that changed their definition of organ response.
Given the rarity of AL amyloidosis, our sample size is small and from a single referral center.
Although the 24-hour urine collection is cumbersome, we continue to recommend it in patients with AL amyloidosis because replacing the 24-hour urine collection with UPCR would change kidney staging and organ response in 10%-20% of patients. In addition, the correlation between the 2 modalities was moderate at best in patients with nephrotic-range proteinuria.
检测在淀粉样轻链（AL）淀粉样变性患者中用单次晨尿蛋白-肌酐比值（UPCR）替代24小时尿蛋白收集的可行性。
一项回顾性研究，使用Pearson相关系数（r）的线性回归分析，检验不同蛋白尿水平下24小时尿蛋白测量值与UPCR之间的相关性。我们评估了使用这两种不同测量方法如何改变AL淀粉样变性患者的诊断、分期和肾脏反应评估。
我们纳入了265例系统性AL淀粉样变性患者，这些患者于2018年7月至2020年1月期间就诊于波士顿大学淀粉样变性中心，且在同一天接受了两种方法的蛋白尿测量。
24小时尿蛋白收集与UPCR。
在蛋白尿水平为500 - 3000mg/天和>3000mg/天的患者中，24小时尿蛋白与UPCR之间的相关性为中等，r值分别为0.57和0.62。用UPCR替代24小时尿蛋白收集使10%的患者肾脏分期发生改变：77%被重新分类为更差的肾脏分期，23%被重新分类为更有利的分期。肾脏分期的大多数变化（85%）发生在>3000mg/天的队列中。有35例患者通过同时进行24小时尿蛋白收集和UPCR评估肾脏反应，并至少间隔6个月就诊。在这些患者中，20%的患者24小时尿蛋白收集与UPCR结果不一致，从而改变了他们器官反应的定义。
鉴于AL淀粉样变性的罕见性，我们的样本量较小且来自单一转诊中心。
尽管24小时尿蛋白收集操作繁琐，但我们仍建议在AL淀粉样变性患者中使用该方法，因为用UPCR替代24小时尿蛋白收集会使10% - 20%的患者肾脏分期和器官反应发生改变。此外，在肾病范围蛋白尿患者中，这两种检测方法之间的相关性充其量为中等。
