ULTRASTRUCTURAL and HISTOCHEMICAL STUDIES OF VASCULAR LESIONS IN MARFAN'S SYNDROME, WITH REPORT OF 4 AUTOPSY CASES

Abstract

Histochemical observation was conducted on arterial lesion in 4 cases of Marfan's syndrome and electron microscopic observation was also carried out on the aorta and gastroepiploic artery in 2 of the 4 cases. Acid mucopolysaccharide (AMPS) noted In cystic medionecrosis demonstrated meshwork of spheres and threads, and showed the same structure as the ground substances widely distributed in the mesenchymal connective tissues including normal arteries and as AMPS in cystic medionecrosis‐like lesions such as arteriosclerosis, mesoaortitis syphilitica, and aortitis syndrome (Takayasu's disease). In histochemical observation, there was found no distinct qualitative difference between AMPS in Marfan's syndrome and that in controls. The overaccumulation of AMPS is not a direct cause of vascular lesions in Marfan's syndrome. The pattern of degeneration of elastic fibers was peculiar to Marfan's syndrome but it also resembled senile change. Degeneration of elastic fibers was accompanied by regeneration in the same area. There was observed no electron microscopic anomaly in collagen fibers nor was found anomaly of fibrlllogenesis in media smooth muscle cells. From the point of view of cell pathology, attribution of the cause of vascular lesion merely to some enzyme deficiency results in much contradiction.

Phenotypic Alteration of Vascular Smooth Muscle Cells Precedes Elastolysis in a Mouse Model of Marfan Syndrome

“…Elastic fiber calcification, intimal hyperplasia, and abnormal deposition of matrix elements were observed widely in medium-to-large elastic arteries. Takebayashi et al 41,42 had previously reported an odd appearance of fragmented elastic laminae in the media of the aorta and peripheral arteries in patients with MFS. This "osmiophilic elastolysis" was characterized by the accumulation of an electron-dense and granular material on the surface of and within elastic fibers.…”

An animal model of the marfan syndrome

“…The specific defect underlying the Marfan syndrome is not known, but the phenotypic manifestations and the autosomal dominant inheritance suggest that the defect results in abnormal structural protein( s) of connective tissue (McKusick, 1972; 'Address reprint requests to T. E. Besser, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040. Takebayashi et al, 1973;Saruk and Eisenstein, 1977). Patients with the Marfan syndrome characteristically exhibit joint laxity, thin limbs, arachnodactyly, ectopia lentis, and dilation of the aortic root leading eventually to dissecting aortic aneurysm.…”

Marfan syndrome: demonstration of abnormal elastic fibers in skin

“…The histological and ultrastructural observations have indieated that the major pathologic feature of the vascular lesions in Marfan syndrome resides in the elastie tissues; fragmentation and sparsity of the elastic fibers, eracks and holes in their amorphous material, and formation of new elastin and non-banded microfibrils (12,(14)(15)(16)(17). The collagen fibers appeared normal (14-17), or twisted (12).…”