[Psoriasis and bullous dermatoses].

In the last five years we observed in Berlin seven cases of psoriasis vulgaris combined with bullous eruptions of the pemphigoid type. Exogenious factors provoking the bullous eruptions were sun exposure, photochemotherapy and treatment with dithranol. These factors did not cause contact allergy of type IV, but pemphigoid eruption which could be characterised by immunfluorescence.

Investigations on the binding sites of the basement membrane zone for pemphigoid antibodies in vitro. II. Immunohistochemical reactions of the reactive groups.

In continuing our studies on the characteristics of the antigenic structures of the basement membrane, procedures used in histochemistry for the identification and blocking of reactive groups have been adapted in this present work to the pretreatment of cryostat sections of guinea-pig tongue. These sections have then been studied by the indirect immunofluorescence method. By means or reagents, which produce a reversible extinction of the basement membrane fluorescence produced with pemphigoid sera, it proved possible to determine the existence of certain chemical groupings which bind the anti-basement membrane antibodies, namely: free carboxyl groups deriving from amino acids, hydrogen bridges in which the hydroxyl groups from the carbohydrates in the antigen are probably involved, bonds involving the free aldehydes of the antigen (either cross-links from aldehydes, or formation of Schiff's bases with amino groups of the antibodies), and lastly, to a lesser extent, disulphide bonds.

Complement as an essential factor for indirect immunofluorescence in cases of pemphigoid.

Hitherto in the literature no proof has been published of a complement activation on the basement membrane in cases of pemphigoid. In this paper, for the first time, it is demonstrated, even if only in vitro, that complement, whose presence in the region of the basement membrane has long been known, plays an active role in a reaction. Through the action of the haemolytic system (amboceptor and sheep erythrocytes) and of anti C3 on reaction specimens for indirect immunofluorescence in pemphigoid, it is shown that the indicator reaction of the fluorescein-labelled anti-IgG with the immune complex attached to the basement membrane is markedly dependent on complement.

[Stimulation of autoantibody formation in pemphigoid due to proteolytic enzymes?].

Following brief exposure of cryostat sections of human skin to proteolytic enzymes (papain or trypsin), there is an increase in the antibody binding capacity of the basement membrane zone for basement membrane zone antibodies of patients with bullous pemphigoid. In conjunction with findings published in the literature, our results indicate that activation of the basement membrane zone antigens by proteolytic enzymes is associated with an increase in antigenicity which results in the formation of auto-antibodies of the basement membrane zone antibody type.