The placenta in pseudoxanthoma elasticum: clinical, structural and immunochemical study.

Pseudoxanthoma elasticum (PXE) is a rare genetic disorder clinically characterized by skin, cardiovascular and eve manifestations, mainly due to calcification and fragmentation of elastic fibres. although infrequent, complications during pregnancy in nomen affected by PXE have been reported. The aim of the present stud! was to compare structural features of placentae at term from 14 control and 15 PXE-affected nomen, in order to better understand if and hen: abnormal mineral and/or matrix accumulation might affect placental function in PSE. In all cases, pregnancy, fetus growth and delivery were normal. Both gross and light microscopy examination did not reveal dramatic differences between placentae of PSE patients and controls, with regard to weight, dimensions, infarcts, thrombi, inflammatory lesions or vessels. However, necrotic changes and mineralization appealed statistically more pronounced in PXE. By electron microscopy the most remarkable differences between PXE and control placentae were observed in the localization and morphology of mineral precipitates; a significant higher deposition of mineral precipitates was observed associated with the ´matrix´-type fibrinoid and among collagen fibrils, especially on the maternal side. Immunocytochemistry revealed the presence of vitronectin and fibronectin associated with the PXE-specific mineralizations and the absence of mineralization on the small and scarce elastic fibres in either controls or in PXE.