title: Immunohistochemical studies of amyloid P component and fibronectin in erythropoietic protoporphyria.
abstract: Immunofluorescence staining of exposed skin from patients with erythropoietic protoporphyria (EPP) with antibodies to serum amyloid P component (SAP) and to fibronectin produced striking fluorescence of abnormal vascular structures in the upper dermis. An appearance of linear fluorescence along the dermo-epidermal junction with anti-SAP was the result of confluent staining of papillary oxytalan fibres. Amyloid P component (AP) was localized in ultrastructural immunoperoxidase studies to the peripheral (abluminal) regions of thickened dermal vessel walls, the site of maximum concentration of an amorphous matrix containing microfibrillar structures; antibodies to SAP did not bind to leaflets of the reduplicated vascular basal lamina. The characteristic thickening and reduplication of blood vessel walls seen with the electron microscope in EPP therefore involves increased local deposition of both AP and fibronectin.
mesh_terms: D000682:Amyloid / Q000032:analysis*; D005353:Fibronectins / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008854:Microscopy, Electron; D011164:Porphyrias / Q000473:pathology*; D000683:Serum Amyloid P-Component; D012867:Skin / Q000648:ultrastructure; D012871:Skin Diseases / Q000473:pathology*; D014018:Tissue Distribution
chemical_list: D000682:Amyloid; D005353:Fibronectins; D000683:Serum Amyloid P-Component