Studies in immunodermatology. VII. Four-compartment system studies of IgG in stratum corneum and of stratum corneum antigen in biopsies of psoriasis and control dermatoses.

Biopsies of skin lesions from 50 cases of psoriasis and from 42 cases with other dermatoses were studied by the methods described in the foregoing report, that is by the four-compartment by the methods described in the foregoing report, that is by the four-compartment immunofluorescent (IF) system for detecting stratum corneum autoantibodies and in vivo binding of IgG in psoriatic scales at the site of the stratum corneum antigen. They were also studied histologically. Early and fully developed psoriatic lesions tended to have more widespread deposits of IgG in the stratum corneum than receding lesions. In biopsies with widespread IgG deposits the stratum corneum antigen usually could not be demonstrated because of blocking by in vivo bound IgG. Of the 42 control biopsies of skin lesions from patients with other dermatoses which were examined with this system two gave the IF staining patterns which were seen most commonly in psoriatic lesions. In these two cases strong widespread IgG deposits occurred in compartment 3, and 4 was very similar to compartment 3. One case was diagnosed as lichen planus and one as cornu cutaneum. Comparisons of the IF findings in psoriatic and control lesion biopsies indicate that significantly more of the former have: (1) IgG deposits at the combining sites of stratum corneum antibodies (92 vs. 50%) and (2) no demonstrable stratum corneum antigen because of 'blocking' by in vivo bound IgG, i.e. compartment 3 like 4 (56 vs. 7%). A highly significant inverse relation between the in vivo deposits of IgG and demonstrability of stratum corneum antigen appeared regardless of the clinical condition. This observation lends support to the view that the IgG which is bound to the sites of the stratum corneum antigen in ski; lesions may in fact be in vivo bound stratum corneum antoantibody.