Nephrology Division, School of Medicine, University of São Paulo, São Paulo-SP, Brazil.
Pathology Division, University of São Paulo School of Medicine, Av. Dr. Enéas de Carvalho Aguiar, 255, 7º andar, Cerqueira Cesar, São Paulo-SP, Brazil.
J Nephrol. 2021 Aug;34(4):1147-1156. doi: 10.1007/s40620-020-00938-3. Epub 2021 Feb 11.
Renal thrombotic microangiopathy (rTMA) is one of many vascular findings in Lupus Nephritis (LN). However, the influence of rTMA on prognosis has not been well established. The objective of this study was to evaluate the clinical and pathological aspects of patients with lupus and rTMA in kidney biopsy.
Analysis of medical reports and kidney biopsy of 253 patients with LN, between January 2012 and December 2018.
Among our 253 patients, 43 (17%) showed acute or chronic TMA lesions on kidney histology This group had a significantly lower estimated glomerular filtration rate (eGFR) at the time of biopsy (24.1 vs. 64.15 ml/min/1.73m2, p < 0.001), at 1 year of follow up (28.1 vs. 90.7 ml/min/1.73m2, p < 0.001), and at the end of follow up (25.4 vs. 81.55 ml/min/1.73m2, p < 0.001). More patients in the rTMA group reached the composite endpoint of eGFR < 15 mL/min/1.73m2 or death or dialysis (82.9% vs. 32.9%, p < 0.001). When comparing the classical clinical TMA features, the rTMA group had higher percentages of anemia, thrombocytopenia, low haptoglobin levels, but not higher lactate dehydrogenase (LDH) levels (> 214 U/L). Combining these variables in a definition of clinical TMA, the rTMA group had a statistically higher percentage of clinical TMA (20.9% vs. 4.33%, p = 0.001). As expected, TMA group showed higher systolic blood pressure (SBP) (130 vs 129.5 mmHg, p = 0.01). Concerning histopathological features, rTMA group had significantly higher activity (9.0 vs. 6.0, p = 0.001) and chronicity (4.0 vs. 3.0, p = 0.001) scores, also a higher percentage of patients presented with crescents (76.7% vs. 57.1%, p = 0.012).
The classical clinical TMA criteria were unable to predict the presence of tissue TMA, suggesting a probably renal-limited TMA that may occur independently of systemic evident factors. Therefore, renal biopsy remains the critical method for diagnosing an important prognostic feature.
肾血栓性微血管病（rTMA）是狼疮肾炎（LN）众多血管病变之一。然而，rTMA 对预后的影响尚未得到很好的证实。本研究的目的是评估狼疮肾活检中伴有 rTMA 患者的临床和病理特征。
分析 2012 年 1 月至 2018 年 12 月期间 253 例 LN 患者的病历报告和肾活检结果。
在我们的 253 例患者中，43 例（17%）在肾组织学上显示出急性或慢性 TMA 病变。与无 rTMA 组相比，该组在肾活检时（24.1 与 64.15 ml/min/1.73m2，p<0.001）、1 年随访时（28.1 与 90.7 ml/min/1.73m2，p<0.001）和随访结束时（25.4 与 81.55 ml/min/1.73m2，p<0.001）的估算肾小球滤过率（eGFR）明显更低。rTMA 组有更多患者达到 eGFR<15 ml/min/1.73m2 或死亡或透析的复合终点（82.9%与 32.9%，p<0.001）。在比较经典的临床 TMA 特征时，rTMA 组的贫血、血小板减少、低血红蛋白水平的百分比更高，但乳酸脱氢酶（LDH）水平（>214 U/L）没有更高（均为 p>0.05）。将这些变量纳入临床 TMA 的定义中，rTMA 组的临床 TMA 百分比明显更高（20.9%与 4.33%，p=0.001）。正如预期的那样，TMA 组的收缩压（SBP）（130 与 129.5mmHg，p=0.01）更高。在组织病理学特征方面，rTMA 组的活动度（9.0 与 6.0，p=0.001）和慢性度（4.0 与 3.0，p=0.001）评分显著更高，也有更高比例的患者出现新月体（76.7%与 57.1%，p=0.012）。
经典的临床 TMA 标准不能预测组织 TMA 的存在，这表明可能存在肾局限性 TMA，这种 TMA 可能独立于系统性明显因素发生。因此，肾活检仍然是诊断重要预后特征的关键方法。
