Immunofluorescence demonstration of type IV collagen and a noncollagenous glycoprotein in thickened vascular basal membranes in protoporphyria.

Specific rabbit antibodies to type IV collagen isolated from a basement membrane producing mouse tumor were used in indirect immunofluorescence tests to study the thickened vascular basement membrane in skin biopsies from patients with erythropoietic porphyria (EPP) and from protoporphyric mice. In addition, rabbit antibodies to a noncollagenous, basement membrane specific glycoprotein also derived from the mouse tumor were tested. It was shown that normal as well as altered vascular basement membranes in both the human and the murine skin specimens react with the anti-type IV collagen and the antiglycoprotein antibodies. A particular strong reaction in the diseases skin indicated that formation of new vascular basement membrane layers involved deposition of the major structural proteins which also constitute normal basement membrane matrices.