Overexpression of type IV collagen in chorionic villi hydatidiform mole

To investigate the characteristic structure of hydatidiform mole, type IV c ollagen expression was determined in human villous tissues obtained from no rmal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirec t immunofluorescent staining was performed to detect type IV collagen with specific monoclonal antibody, and Northern blot analysis was performed to a ssess expression of messenger ribonucleic acid for the al(IV) chain. In add ition, serum levels of type I, III, and TV collagen were measured by RIA. I mmunohistochemical staining for type IV collagen revealed stronger staining of the trophoblastic basement membrane in hydatidiform mole than in normal pregnancy. Northern blot analysis revealed that the villous expression of messenger ribonucleic acid for the al(IV) chain was significantly increased in hydatidiform moles compared with normal pregnancy (P < 0.01). Although there were no differences in the serum type I and III collagen levels betwe en hydatidiform mole and normal pregnancy, the type IV collagen level was s ignificantly higher in patients with hydatidiform mole than in normal pregn ancy (P < 0.05). These results suggest that type IV collagen might play an important role in determining the pathophysiology and structure of hydatidi form mole.