肾活检标本包埋后免疫电镜技术

Post-embedding immunoelectron microscopy of renal biopsies

目的 :探讨肾活检标本树脂包埋及低温包埋的免疫电镜技术。方法 :选择 9例膜性肾病和 7例IgA肾病的肾活检标本 ,分别进行IgG及IgA的免疫电镜标记 ,观察不同的固定方法及环氧树脂、低温包埋剂包埋后的免疫标记结果。结果 :低温包埋剂LRWhiteresin和LowicrylK4M包埋后的标本 ,IgG和IgA的标记密度均较高 ,两种包埋剂的标记效果相同 ;但LRWhiteresin对超微结构的保存优于LowicrylK4M。常规固定方法、Epon812包埋的标本 ,IgG及IgA均不能标出 ;混合固定液 (多聚甲醛加戊二醛 )固定、Epon812包埋的标本 ,IgG及IgA均可标出 ,但与低温包埋剂相比 ,标记密度较低。结论 :低温包埋剂LRWhiteresin和LowicrylK4M对免疫标记效果好 ,但较昂贵 ,难应用于临床。树脂包埋剂虽然免疫标记效果略差 ,但可作为一种诊断免疫电镜方法。

SUMMARY Objective: To compare methods of immunoelectron microscopy of renal biopsies embedded with epoxy resin and low temperature embedding media. Methods: 9 cases of membranous nephropathy and 7 cases of IgA nephropathy were collected for ultrastructural immunogold labeling of IgG and IgA. Renal specimens were processed in different fixatives and embedding media. Results: Higher labeling for IgG and IgA were observed in specimens embedded in LR White resin and Lowicryl K4M, whereas preservation of tissue structure embedded in LR White resin was better than that in Lowicryl K4M. Routine processing method for electron microscopy was not allowed to get specific labeling of IgG and IgA on renal biopsies; but specimens fixed in 4% polyformaldehyde mixed with 0.1% glutaraldehyde, embedded in Epon 812 could be labeled for IgG and IgA specifically, although its labeling density was lower than low temperature embedding media. Conclusion: It is suggested that LR White resin should be selected as embedding media in pathologic study, although it is expensive. Renal biopsy specimens embedded in epoxy resin could be labeled for IgG and IgA successfully, which can be used as a way of diagnostic electron microscopy in pathologic diagnosis of kidney disease.