IgA肾病肾小管周围毛细血管的变化及临床意义

Change of Peritubular Capillaries in Patients with IgA Nephropathy and its Clinical Significance

目的:探讨IgA肾病患者肾小管周围毛细血管与血管内皮细胞生长因子(VEGF)及其受体VEGF-R2(Flk-1)的表达变化及临床意义。方法:对24例不同病理改变的IgA肾病肾组织进行序列切片。采用免疫组织化学SP法检测肾小管间质中VⅢ因子、VEGF和Flk-1的表达。对各指标之间与临床病理改变之间进行相关分析。结果:IgA肾病患者肾组织中,肾小管间质中微血管密度在中度病变的病人表达最多,在重度者表达最少(P<0.05)。VEGF主要表达于肾小管上皮细胞,Flk-1主要表达于肾间质中肾小管周围毛细血管内皮细胞。两者与肾小管周围毛细血管密度呈正相关(P<0.05)。在中、重度组肾小管间质肾小管周围毛细血管的微血管密度与患者尿NAG酶的含量呈负相关(r=-0.57,P<0.05),与间质纤维化呈负相关性(r=-0.82,P<0.01)。结论:IgA肾病肾小管周围毛细血管密度变化与肾小管间质的病变密切相关。血管内皮细胞生长因子可能是导致肾小管周围毛细血管密度变化的主要原因。

Objective： To investigate abnormalities of peritubular capillaries in patients with IgA nephropathy （IgAN） and its clinical significance. Methods：24 patients with biopsy - proven IgAN were enrolled and divided according to pathological changes. Immunohistochemistry was performed in serial sections to detect the expression of Factor VⅢ - related antigen （FVⅢ）, VEGF and flk- 1 in tubulo- interstitial region, the relationship between their expressions and clinicopathological changes were analyzed. Results：The density of peritubular capillaries reached maximum in IgAN patients with moderate lesion. VEGF was mainly expressed in tubular epithelial cells. The expression of flk - 1 was correlated with FVⅢ, mainly located in peritubular capillary endothelial cells. The density of VEGF positive cells showed a positive correlation with the microvessel density（P〈0.05）. In patients with moderate to .severe lesion, inicrovessel density was correlated with urine NAG level（ r = - 0.57, P 〈 0.05 ）and interstitial fibrosis （ r = - 0.82, P 〈 0.001 ）. Conclusion： Changes of peritubular capillary density was closely related with tubulo - interstitial lesion in IgAN. VEGF expression in tubules contributed to the capillary regression in IgAN.