The placenta in pseudoxanthoma elasticum: Clinical, structural and immunochemical study

Pseudoxanthoma elasticum (PXE) is a rare genetic disorder clinically charac terized by skin, cardiovascular and eve manifestations, mainly due to calci fication and fragmentation of elastic fibres. although infrequent, complica tions during pregnancy in nomen affected by PXE have been reported. The aim of the present stud! was to compare structural features of placentae at te rm from 14 control and 15 PXE-affected nomen, in order to better understand if and hen: abnormal mineral and/or matrix accumulation might affect place ntal function in PSE. In all cases, pregnancy, fetus growth and delivery we re normal. Both gross and light microscopy examination did not reveal drama tic 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 p ronounced in PXE. By electron microscopy the most remarkable differences be tween PXE and control placentae were observed in the localization and morph ology of mineral precipitates; a significant higher deposition of mineral p recipitates was observed associated with the 'matrix'-type fibrinoid and am ong collagen fibrils, especially on the maternal side. Immunocytochemistry revealed the presence of vitronectin and fibronectin associated with the PX E-specific mineralizations and the absence of mineralization on the small a nd scarce elastic fibres in either controls or in PXE. (C) 2001 Harcourt Pu blishers Ltd.