Hahnemann University Hospital
Publishes on Systemic Sclerosis and Related Diseases, Skin and Cellular Biology Research, Dermatological and Skeletal Disorders. 162 papers and 13.4k citations.
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A subclassification of SSc patients is proposed by a group of experienced investigators. The subsets are defined by skin involvement with limited cutaneous SSc (lcSSc) patients having no taut skin proximal to the knees, elbows or clavicles and diffuse cutaneous SSc (dcSSc) patients having truncal skin tautness.
The purpose of this study was to determine the frequency, distribution, and nature of cellular infiltrates in 108 skin biopsies from patients with systemic scleroderma (SS) and localized scleroderma (LS). Cellular infiltrates, perivascular or diffuse, were noted in 49% of SS and 84% of LS patients and consisted of lymphocytes, plasma cells, and macrophages. No correlation was noted between the presence or severity of skin cellular infiltrates and serum serologic abnormalities.
Collagen VI was solubilized with pepsin from human placenta and used for preparing rabbit antisera. Major antigenic determinants were located in the central region of the antigen including triple-helical and globular structures. Antisera prepared against a constituent-chain showed preferential reactions with unfolded structures. Antibodies were purified by affinity chromatography and failed to cross-react with other collagen types I-V and with fibronectin. These antibodies demonstrated intracellular and extracellular collagen VI in fibroblast and smooth muscle cell cultures. Immunoblotting identified a disulfide-bonded constituent chain about twice as large as those of the pepsin fragments in both cell cultures and tissue extracts. Rotary shadowing electron microscopy indicated that the increase in mass is due to larger globular domains present at both ends of collagen VI monomers. Indirect immunofluorescence demonstrated a wide occurrence of collagen VI in connective tissue particularly of large vessels, kidney, skin, liver and muscle. Collagen VI is apparently not a typical constituent of cartilage or of basement membranes. Ultrastructural studies using the immunoferritin technique showed collagen VI along thin filaments or in amorphous regions of aortic media or placenta but not in association with thick, cross-striated collagen fibrils or elastin. This supports previous suggestions that collagen VI is a constituent of microfibrillar structures of the body.