Abstract
Epidermolysis bullosa is classified into three main groups by the level of cleavage within the skin: (1) epidermolysis bullosa simplex; (2) junctional epidermolysis bullosa; and (3) dystrophic epidermolysis bullosa. The last group contains six subgroups, two of which are inherited in a dominant mode and four in a recessive manner. The two subgroups of dominantly inherited dystrophic epidermolysis bullosa are distinguished by the presence (Pasini form) or absence (Cockayne-Touraine form) of albopapular lesions, which appear on the lower back of some patients at adolescence. An early histochemical examination of our case revealed an increased amount of degraded dermatan sulfate in the skin of a patient with the Pasini form of dystrophic epidermolysis bullosa. The present study was designed to examine glycosaminoglycan chains of proteoglycans in the skin of a patient with Pasini form by histochemical and immunohistochemical methods. The monoclonal antibodies used in the present study were: 2B1 (against chondroitin sulfate large proteoglycan), 3B3 (against a stub of ΔDi-6S unit binding to core protein obtained from chondroitin sulfate proteoglycan with chondroitinase ABC), 6B6 (against small proteoglycan with dermatan sulfate and chondroitin sulfates), and CS56 (reacts with chondroitin sulfates but not with dermatan sulfate). A histological examination revealed no dermoepidermal separation. In the dermis, the papillary and subpapillary layers were slightly homogeneous, and also showed a strong affinity for alcian blue or toluidine blue, but these phenomena was abolished either by treatment with chondroitinase ABC or in the presence of MgCl2 at 0.3M, but was resistant to streptomyces hyaluronidase. When immunostaining with monoclonal antibodies was carried out, the papillary and subpapillary layers were strongly stained with the 2B1 and 6B6 antibodies, as compared to the control sections. These results thus suggest the presence of degraded dermatan sulfate proteoglycan in the upper dermis of albopapular lesions in the Pasini form of dystrophic epidermolysis bullosa.
