SEQUENTIAL DERMAL MICROVASCULAR AND PERIVASCULAR CHANGES IN THE DEVELOPMENT OF SCLERODERMA

It has been previously proposed that there is a primary microvascular abnormality in patients with systemic sclerosis. In this study using c onventional light and electron microscopy, immunohistochemistry, and l abelled adenosine uptake techniques, changes in the dermal microvascul ature have been related to the various clinical stages of skin disease in systemic sclerosis. The earliest pathological changes are seen in clinically normal skin. They constitute changes in endothelial cell fu nction and their consequences. Perivascular oedema is an early feature . With progression in the clinical disease, there is, at first, an inf lammatory cell infiltrate into the dermis, particularly the papillary and mid-dermis, and platelet aggregation within vessels. Further clini cal progression is associated with increasing dermal fibrosis, loss of adnexae, and vascular effacement. It is postulated that the recruitme nt of different types of mononuclear cells into the dermis is causally linked with the preceding endothelial cell dysfunction and the subseq uent induction of fibroblast proliferation and collagen synthesis.