In vivo analysis of IgE autoantibodies in bullous pemphigoid: a study of 100 cases.
BACKGROUND
Bullous pemphigoid (BP) is an acquired autoimmune blistering disease characterized by subepidermal blister formation, in vivo linear deposition of immunoglobulin G (IgG) and complements at the dermal-epidermal junction (DEJ). The circulating IgG autoantibodies are directed against two epidermal hemidesmosomal glycoproteins: BP180, also known as type XVII collagen (COL17), and BP230. In addition, recent studies have shown that IgE autoantibodies may be involved in the pathogenesis of BP, although in vivo IgE deposition in lesional skin has not been fully characterized in large numbers of BP patients.


OBJECTIVE
This study investigated the incidence of in vivo deposition of IgE autoantibodies at the DEJ in lesional skin from a large number of BP patients.


METHODS
Peri-lesional skin samples from 100 patients who met the clinical and histopathological criteria for BP were investigated by direct immunofluorescence for the deposition of autoantibodies and complement. Patients' sera were also investigated by enzyme-linked immunosorbent assay and indirect immunofluorescence.


RESULTS
18% of BP patients were found to show IgE deposition at the DEJ. Disease severity, clinical course and outcome did not differ between IgE-positive and IgE-negative patients. In 3 IgE-positive cases, IgG was undetectable in vivo, and these cases showed atypical manifestations.


CONCLUSIONS
The results of in vivo IgE deposition may not be useful in predicting the disease course of BP, although predominant IgE deposition could alter the pattern of clinical manifestations.
Department of Dermatology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan. Electronic address: parallelridge@yahoo.co.jp.
Reine
R
Moriuchi
Department of Dermatology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan. Electronic address: nishie@med.hokudai.ac.jp.
Wataru
W
Nishie
Department of Dermatology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan. Electronic address: h-ujiie@med.hokudai.ac.jp.
Hideyuki
H
Ujiie
Department of Dermatology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan. Electronic address: natsuga@med.hokudai.ac.jp.
Ken
K
Natsuga
Department of Dermatology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan. Electronic address: shimizu@med.hokudai.ac.jp.
Hiroshi
H
Shimizu
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000032:analysis* / Q000097:blood; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis* / Q000097:blood; D008297:Male; D008875:Middle Aged; D010391:Pemphigoid, Bullous / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D012867:Skin / Q000187:drug effects / Q000276:immunology*
D001323:Autoantibodies; D015415:Biomarkers; D007073:Immunoglobulin E
Autoantibody; Bullous pemphigoid; Direct immunofluorescence study; Immunoglobulin E; In vivo study; Type XVII collagen