Division of Nephrology and Hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, 216-8511, 2-16-1, Sugao, Miyamae-ku, Kawasaki, Kanagawa, Japan.
Department of Nephrology, Kameda Medical Center, Chiba, Japan.
BMC Nephrol. 2020 Jun 29;21(1):240. doi: 10.1186/s12882-020-01876-9.
Preeclampsia (PE) refers to the development of hypertension and new-onset proteinuria or progressive organ damage (especially kidney) in a previously normotensive pregnant women after 20 weeks of gestation. Thus, new-onset nephrotic syndrome due to PE before 20 weeks of gestation seems to be rare, making its diagnosis difficult in this time period.
A 28-year-old woman presented with a new-onset nephrotic syndrome at 16 weeks of gestation. A high dose of oral glucocorticoids (prednisolone, 40 mg) was initiated for presumed glomerulonephritis since she presented with severe nephrotic syndrome before 20 weeks of gestation, however, the treatment was not effective. At 21 weeks of gestation, we confirmed that the soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio was very high (sFlt-1, 13,400 pg/mL; PlGF, 21.9 pg/mL; serum sFlt-1/PlGF ratio 611.9). Therefore, we diagnosed nephrotic syndrome due to PE, and oral glucocorticoids were discontinued. After she underwent a cesarean section at 24 weeks & 3 days, we performed a kidney biopsy. Focal segmental sclerotic lesions with epithelial cell hyperplasia and foam cells in the tubular poles were seen on light microscopy. On immunofluorescence tests, C4d staining showed linear peripheral patterns in the glomeruli. Electron microscopy revealed diffuse subendothelial edema with focal foot process effacement. The histological diagnosis was severe glomerular endotheliosis with focal segmental glomerulosclerosis. Furthermore, the histology of placenta was consistent with PE. Eight months after delivery, her proteinuria disappeared completely.
We not only confirmed an abnormal serum sFlt-1/PlGF ratio but also presented the histology compatible with pure PE in the kidney and placenta in a case of nephrotic syndrome before 20 weeks of gestation. The serum sFlt-1/PlGF ratio may be useful in determining the treatment strategy for atypical cases of pregnant women with nephrotic syndrome, particularly before 20 weeks of gestation.
子痫前期（PE）是指妊娠 20 周后原本血压正常的孕妇出现高血压和新出现的蛋白尿或进行性器官损伤（尤其是肾脏）。因此，妊娠 20 周前出现的新发生的肾病综合征似乎很少见，这使得在此期间的诊断变得困难。
一名 28 岁女性在妊娠 16 周时出现新发生的肾病综合征。由于患者在妊娠 20 周前出现严重的肾病综合征，因此给予大剂量口服糖皮质激素（泼尼松龙，40mg）治疗，推测为肾小球肾炎，但治疗无效。妊娠 21 周时，我们证实可溶性 fms 样酪氨酸激酶-1（sFlt-1）/胎盘生长因子（PlGF）比值非常高（sFlt-1，13400pg/ml；PlGF，21.9pg/ml；血清 sFlt-1/PlGF 比值 611.9）。因此，我们诊断为 PE 所致的肾病综合征，并停用了口服糖皮质激素。妊娠 24 周 3 天时，患者行剖宫产术，术后我们进行了肾活检。光镜下可见局灶节段性硬化病变，伴有肾小管顶端上皮细胞增生和泡沫细胞。免疫荧光检查显示，C4d 染色在肾小球周围呈线性模式。电子显微镜显示弥漫性亚内皮水肿，伴局灶足突消失。组织学诊断为严重肾小球内皮细胞病伴局灶节段性肾小球硬化。此外，胎盘组织学符合 PE。产后 8 个月，患者的蛋白尿完全消失。
我们不仅证实了异常的血清 sFlt-1/PlGF 比值，还在妊娠 20 周前肾病综合征患者的肾脏和胎盘中发现了与单纯性 PE 相符的组织学表现。血清 sFlt-1/PlGF 比值可能有助于确定妊娠妇女非典型肾病综合征的治疗策略，尤其是在妊娠 20 周前。
