Composition and mechanism of deposition of the intercellular substance in parakeratotic psoriatic epidermis.
In order to elucidate both the mechanism of deposition and the composition of the substance that is observed mainly the intercellular spaces (ICS) and to a lesser extent in the cytoplasm of psoriatic epidermis, five cases of psoriasis vulgaris were examined using conventional histology and histochemistry, electron microscopy, and direct immunofluorescence technique with or without incubation in acid citrate buffer or digestion by fibrinolysin. The substance was found by electron microscopy to be rather dense and finely granular, and that in the parakeratotic horny layer was diastase-resistant PAS positive, and showed positive immunofluorescence for immunoglobulins, complement, and fibrinogen. The fluorescence was not significantly altered by pre-incubation of the tissue sections in acid citrate buffer, but was significantly diminished by predigestion of tissue sections with fibrinolysin. From these findings, we concluded that the substance is likely to consist of and be derived from the components of plasma protein, and to play a role in the formation of the parakeratotic psoriatic horny layer. It also seems that the deposition of this substance is rather the result of the coagulation of plasma protein than that of antigen-antibody reactions.
Department of Dermatology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160, Japan.
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Kimura
D000293:Adolescent; D000328:Adult; D001707:Biopsy, Needle; D001798:Blood Proteins / Q000378:metabolism*; D002648:Child; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D018450:Disease Progression; D004817:Epidermis / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan; D008297:Male; D008854:Microscopy, Electron; D010241:Parakeratosis / Q000473:pathology*; D011565:Psoriasis / Q000473:pathology*; D018570:Risk Assessment; D012494:Sampling Studies; D012720:Severity of Illness Index
D001798:Blood Proteins