Endoglin (CD105) expression in the development of haemorrhoids.
BACKGROUND
Conventional pathogenesis of haemorrhoid emphasized the anchoring connective tissue system, whereas the vascular changes were ignored. The aim of this study was to clarify vascular changes of haemorrhoid disease.


METHODS
Forty-six samples of grade III and grade IV haemorrhoid tissue were selected for an in vitro study. We assessed the expressions in endoglin (CD105), an accessory protein in transforming growth factor-beta receptor complex, in CD34 and in vascular endothelial growth factor by using an immunohistochemical method. Microvascular density was calculated to correlate the expression of endoglin.


RESULTS
Microvascular density was higher in haemorrhoid tissue than in normal anal and lower rectal tissues. CD34 was demonstrated in whole vessels in the haemorrhoids. However, endoglin, a proliferative marker of neovascularization, was present in only 25 of 46 (54%) haemorrhoidal vessels, and its immunoactivity was prominent in venules larger than 100 micro m. Thrombosis formation and stromal vascular endothelial growth factor was significantly associated with the presence of endoglin immunoactivity.


CONCLUSIONS
The results of this study suggest that neovascularization is one important phenomenon of haemorrhoid disease, along with conventional venous dilatation and arteriovenous communication. In addition, thrombosis and stromal vascular endothelial growth factor might be important factors in promoting vascular proliferation.
Chung
Y-C
YC
Hsin-Chu General Hospital, Taiwan.
Hou
Y-C
YC
Pan
A C-H
AC
D000328:Adult; D001003:Anal Canal / Q000098:blood supply; D015703:Antigens, CD; D018952:Antigens, CD34 / Q000378:metabolism; D000071063:Endoglin; D005260:Female; D006484:Hemorrhoids / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology; D011956:Receptors, Cell Surface; D012008:Recurrence; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D015703:Antigens, CD; D018952:Antigens, CD34; C064206:ENG protein, human; D000071063:Endoglin; D011956:Receptors, Cell Surface; D019010:Vascular Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A