伴足细胞尿的IgA肾病的临床病理特征

目的 探讨伴足细胞尿的IgA肾病（IgAN）患者的临床病理特点。方法 入选IgAN患者36例,其中男性20例,女性16例,平均年龄（34．1±12．2）岁。10例健康志愿者为健康对照。足细胞排泄的定量检测采用尿沉渣涂片免疫组化染色直接计数。进行尿液足细胞排泄与肾脏病理的相关分析。结果 （1）IgAN患者尿细胞podocalyxin阳性率为61%,健康对照组为0（P＜0．05）。（2）与非大量蛋白尿（＜3．0 g/24 h）IgAN患者比较,大量蛋白尿（≥3．0 g/24 h）IgAN患者的尿液足细胞检测阳性率、尿液足细胞排泄数、足细胞与尿肌酐的比值以及足细胞占尿液小管上皮细胞的百分数均显著增高（P＜0．05）。IgAN患者足细胞排泄水平与蛋白尿水平呈正相关（r=0．446,P=0．007）。（3）与无足细胞尿的患者比较,伴足细胞尿的IgAN患者的蛋白尿水平显著增高,血浆白蛋白水平显著降低,肾小管上皮细胞与尿肌酐的比值亦显著增高（P＜0．05）。但伴与不伴足细胞尿的2组IgAN患者在年龄、性别、血压、Scr、血红蛋白水平以及血浆脂质代谢等方面差异均无统计学意义（P＞0．05）。（4）尿足细胞的排泄与细胞新月体或细胞纤维性新月体、小球血管襻腔狭窄和足突广泛融合病变有关,而与系膜、内皮细胞病变及局灶基底膜增厚无关。伴足细胞尿的患者肾小球和肾小管间质纤维化更明显（P＜0．05）。伴有新月体的患者其尿液足细胞排泄水平、尿液上皮细胞和管型的排泄均增加（P＜0．05）。结论 足细胞尿不仅是IgAN患者肾小球损伤的结果,也是IgAN患者活动性损伤的指标。足细胞尿排泄的水平与蛋门尿水平呈正相关,与肾脏病理类型也有一定的关系。

Clinicopathological characteristics of IgA nephropathy with urinary podocyte excretion

Objective To investigate the clinicopathological characteristics of IgA nephropathy (IgAN) with urinary podocyte excretion（UPE）. Methods (1) Among the 36 enrolled patients with IgAN, 20 were male and 16 were female, with an average age of (34.1±12.2) years. All these patients were diagnosed by renal biopsy. Ten healthy volunteers were served as controls. (2)The UPE level was calculated by urinary sediment smear counting. (3) The correlation between UPE level and renal pathological changes was examined. Results (1)The patients with IgA nephropathy had a higher frequency of podocyturia (61%). No podocyturia was found in healthy controls. (2)The UPE level, as well as UPE/urinary creatinine or UPE/urinary renal epithelial excretion ratio, were significantly elevated in IgAN patients with massive proteinuria (≥3.0 g/24 h). Moreover，the UPE level was positively correlated with 24 h urinary protein excretion（r＝0.446，P＝0.007）. (3)Compared with negative staining patients, patients with positive podocalyxin stain showed significantly higher 24 h urinary protein excretion and urinary renal epithelial cells excretion, while their plasma albumin levels were significantly lower. These two groups had similar distribution in age, gender and frequency of hypertension, and no significant variations were observed concerning the levels of Scr, Hb, cholesterol and triglyceride（P > 0.05）. (4) UPE was related to the injuries of cellular crescent, glomerular disruption of capillaries and extensive epithelial foot process effacement, but not related to the mesangial proliferation, or focal capillary wall thickening. Patients with glomerular crescents showed more severe glomerular sclerosis and interstitial fibrosis (P<0.05). Conclusions Podocyturia is not only a clinical evidence of renal damage, but also a hallmark of the activity of IgAN. Urinary podocyte excretion level in IgAN patients is correlated with 24 h urinary protein excretion and specific pathological damages.