PMC10267980_01
Clinical and histopathological features at the first visit and at the time of relapse. (a-e) Clinical features of blisters, erosions, and erythema on the forehead (a), shoulder (b), and upper arms (c) at the first visit, and those on the face (d), and lower lip (e) at the time of relapse. (f, g) Histopathology of the skin biopsy from the forehead at the time of relapse showing subepidermal blisters with infiltration of neutrophils in the blister and dermis [original magnifications; (f) x40 and (g) x200].
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F1
Physical examination revealed blisters, erosions and erythema on the face (Figure 1a), lips, back, shoulders (Figure 1b) and arms (Figure 1c). Physical examination revealed blisters, erosions and erythema on the face (Figure 1d), shoulder, back, upper arms, and lower lip (Figure 1e). A skin biopsy from the forehead histopathologically showed subepidermal blisters (Figures 1f, g).
The result of various immunological tests at the first visit and at the time of relapse. (a, b) At the first visit, indirect immunofluorescence of 1M NaCl-split skin showing positive reactivity with dermal side for IgG antibodies (a) and with epidermal side for IgM antibodies (b). (c) The results of IgG immunoblotting of normal human dermal extract. The serum at the first visit (lane 4), but not the serum at the relapse (lane 5), reacted with the 290 kDa type VII collagen. (d-g) Direct immunofluorescence at the time of relapse showing positive results for IgG (d), IgM (e), and C3c (f) but negative for IgA (g). (h, i) At the time of relapse, indirect immunofluorescence of 1M NaCl-split skin showing positive reactivity with dermal side for IgG antibodies (h) and with epidermal side for IgM antibodies (i) (all of the immunofluorescence figures: original magnification, x200).
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F2
Circulating IgG anti-BMZ autoantibodies were detected by IIF of normal human skin, which bound to the dermal side of 1 M NaCl-split normal human skin at 1:40 serum dilution (Figure 2a). IgM autoantibodies were bound to the epidermal side of 1 M NaCl-split normal human skin at 1:40 serum dilution (Figure 2b). Immunoblotting of normal human dermal extract detected IgG antibodies to type VII collagen (Figure 2c), while IgG immunoblotting analyses of other substrates were negative. IgM immunoblotting analyses of normal human epidermal extracts, recombinant proteins of NC16a and C-terminal domains of BP180 and concentrated culture supernatant of HaCaT cells were negative. DIF showed linear depositions of IgG, IgM, and C3c, but not IgA, in the epidermal BMZ (Figures 2d-g). IgM antibodies were bound to the epidermal side of the spilt (Figure 2i). IgG type VII collagen ELISA was negative (index 5.78; cut-off < 6.14). Immunoblotting of normal human dermal extract did not detect IgG antibodies to type VII collagen (Figure 2c). IgM immunoblotting analyses using the 4 substrates were negative.