Division of Nephrology, Department of Medicine, Mayo Clinic, Scottsdale, Arizona, USA,
Mayo Clinic Alix School of Medicine, Mayo Clinic, Scottsdale, Arizona, USA.
Am J Nephrol. 2021;52(12):961-968. doi: 10.1159/000520286. Epub 2021 Nov 29.
Current knowledge of risk factors and renal histologic patterns of oxalate nephropathy (ON) not due to primary hyperoxaluria (PH) has been limited to small case series and case reports. Thus, we analyzed and compared clinical risk factors, histologic characteristics, and renal outcomes of patients with biopsy-confirmed ON among a cohort of patients with enteric and nonenteric risk factors.
A clinical data repository of native kidney pathology reports from 2009 to 2020 at all Mayo Clinic sites was used to identify 421 ON cases.
After excluding cases in transplanted kidneys or due to PH, 64 cases remained. Enteric risk factors were present in 30 and nonenteric in 34. Roux-en-Y gastric bypass (17) and pancreatic insufficiency (6) were most common in the enteric hyperoxaluria group. In the nonenteric group, vitamin C (7) and dietary oxalate (7) were common, while no apparent risk was noted in 16. Acute kidney injury (AKI) stage III at the time of diagnosis was present in 60%, and 40.6% required dialysis. Patients in the nonenteric group had more interstitial inflammation (p = 0.01), and a greater number of tubules contained intratubular calcium oxalate (CaOx) crystals (p = 0.001) than the nonenteric group. Patients in the enteric group were more likely to have baseline chronic kidney disease (CKD) (p = 0.02) and moderate-to-severe tubulointerstitial fibrosis and atrophy (IFTA) (OR 3.49, p = 0.02). After a median follow-up of 10 months, 39% were dialysis dependent, 11% received a kidney transplant, and 32% died. On univariate analysis, >10 tubules with CaOx crystals, baseline CKD, and AKI requiring dialysis correlated with the risk of dialysis, transplant, or death. On multivariate analysis, only AKI requiring dialysis correlated with adverse renal outcomes.
This is the largest cohort study of ON not due to PH. Histologic features differ in patients with enteric versus nonenteric risks. Patients in the enteric group are more likely to have baseline CKD and significant IFTA, while patients in the nonenteric group were more likely to have a greater number of tubules with CaOx crystals and corresponding interstitial inflammation. AKI requiring dialysis at the time of diagnosis was the single most significant predictor of adverse renal outcome.
目前，由于原发性高草酸尿症（PH）以外的原因导致的草酸肾病（ON）的风险因素和肾脏组织学模式的相关知识仅限于小的病例系列和病例报告。因此，我们分析和比较了在存在肠内和非肠内危险因素的患者队列中，经活检证实的 ON 患者的临床风险因素、组织学特征和肾脏结局。
使用 2009 年至 2020 年在梅奥诊所所有站点的本地肾脏病理报告的临床数据存储库，确定了 421 例 ON 病例。
在排除移植肾脏或 PH 导致的病例后，仍有 64 例。肠内危险因素存在于 30 例，非肠内危险因素存在于 34 例。Roux-en-Y 胃旁路术（17 例）和胰腺功能不全（6 例）是肠内高草酸尿症组中最常见的。在非肠内组中，维生素 C（7 例）和饮食性草酸盐（7 例）很常见，而 16 例无明显危险因素。诊断时 AKI Ⅲ期的患者占 60%，其中 40.6%需要透析。非肠内组的间质炎症更多（p=0.01），且更多的肾小管内含有管腔内草酸钙（CaOx）晶体（p=0.001）。肠内组的患者更有可能存在基线慢性肾脏病（CKD）（p=0.02）和中重度肾小管间质纤维化和萎缩（IFTA）（OR 3.49，p=0.02）。中位随访 10 个月后，39%的患者依赖透析，11%接受了肾移植，32%的患者死亡。在单变量分析中，>10 个含有 CaOx 晶体的肾小管、基线 CKD 和需要透析的 AKI 与透析、移植或死亡的风险相关。在多变量分析中，只有需要透析的 AKI 与不良肾脏结局相关。
这是最大的非 PH 所致 ON 队列研究。肠内和非肠内风险患者的组织学特征不同。肠内组患者更有可能存在基线 CKD 和显著的 IFTA，而非肠内组患者则更有可能出现更多的含有 CaOx 晶体的肾小管和相应的间质炎症。诊断时需要透析的 AKI 是不良肾脏结局的唯一最显著预测因素。
