Dermatomyositis with prominent mucinous skin change. Histochemical and biochemical aspects of glycosaminoglycans.
Although there is occasionally remarkable accumulation of mucin in the skin lesion of dermatomyositis, no special attention has been paid in regard to mechanisms underlying it. We carried out histochemical and biochemical studies on materials obtained from one case of dermatomyositis, who showed the presence of abundant mucinous material stainable with alcian blue between the collagen bundles throughout the lesional dermis. The major component of the ground substance was identified to be hyaluronic acid. The activity of N-acetyl-beta-glucosaminidase, exoglycosidase that degrades hyaluronic acid in serum of the patient, was equivalent to that of controls. However, heparan sulfate was greatly increased in the urine of the patient in comparison with that of the normal controls in which the major components were chondroitin 4-sulfate and chondroitin 6-sulfate. We think that the increase of hyaluronic acid in the lesional dermis is due to an excess production by the fibroblasts under some immunological stimulation, although its relation to the increased heparan sulfate excretion into the urine of the patient is obscure.
D000118:Acetylglucosaminidase / Q000097:blood; D000368:Aged; D003882:Dermatomyositis / Q000378:metabolism* / Q000473:pathology; D006025:Glycosaminoglycans / Q000378:metabolism* / Q000652:urine; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism; D008297:Male; D009077:Mucins / Q000378:metabolism*; D012867:Skin / Q000473:pathology*
D006025:Glycosaminoglycans; D009077:Mucins; D006820:Hyaluronic Acid; D000118:Acetylglucosaminidase