人胎回肠淋巴组织发生及IgM阳性B细胞的发育

目的 探讨人胎回肠淋巴组织的发生及IgM阳性B细胞在人胎回肠的分布、定位及发育. 方法 收集2003年1月至2005年12月贵阳市各医院妇产科因流产等终止妊娠的9～28周人胎回肠标本30例,男12例、女18例.采用HE染色观察人胎回肠淋巴组织发生,SABC法染色显示IgM阳性B细胞,并用BioMias29图像分析软件对...

Genesis of lymphoid tissue and development of IgM-positive B cells in human fetal ileum

Objective To study genesis of lymphoid tissue and distribution,localization and development of IgM-positive B cells in human fetal ileum.Methods Human fetus specimens from terminated pregnancies,12 males and 18 females with gestational ages of 9-28 weeks,were collected from hospitals in Guiyang,China,between Jan.2003 and Dec.2005.All pregnant women were informed of the purpose of this study and the protocol was approved by the Ethics Committee of Guiyang Medical College.HE staining was adopted to observe the genesis of lymphoid tissue in human fetal ileum.IgM-positive B cells were detected by immunohistochemical SABC staining,and counted by BioMias 29 image analysis software.Relevant data were statistically analyzed.Results In the ilea of 9-week fetus specimens,a small amount of lymphocytes were observed in the mesenchyme out of epithelia,part of which expressed membrane IgM.In the ilea of 17-week fetus specimens,lamina propria lymphocytes aggregated to form solitary lymphoid nodules with an increased amount of IgM-positive B cells.In the ilea of 24-week and older fetus specimens,typical Peyer’s patches could be observed.IgM-positive B cells existed mainly in lymphoid nodules and sporadically in lamina propria connective tissue or chorionic epithelium.Cell counting results showed that IgM-positive B cells in human fetal ilea increased from 12.80±5.72 in 9-12 week to 201.30±36.35 in 25-28 week with statistically significant difference(P<0.05).Conclusion Lymphoid tissue of human fetal ileum wall is nearly mature at 24 weeks old.Human fetal ileum can potentially synthesize and release IgM that is important for constructing and improving fetus intestinal immunity.