Antineutrophil cytoplasmic antibodies of IgA class in neutrophilic dermatoses with emphasis on erythema elevatum diutinum.
OBJECTIVE
To evaluate the prevalence of IgA and IgG antineutrophil cytoplasmic antibodies (ANCAs) in erythema elevatum diutinum in comparison with 2 other groups of neutrophilic dermatoses: Sweet syndrome and pyoderma gangrenosum.


METHODS
Detection of IgA and IgG ANCAs in the serum of patients with neutrophilic dermatoses and characterization of the previously known antigenic targets.


METHODS
All serum was analyzed without knowledge of diagnosis in the Immunology Department, Pitié-Salpêtrière Hospital, Paris, France.


METHODS
Ten patients with erythema elevatum diutinum, 10 with Sweet syndrome, 10 with pyoderma gangrenosum, and 10 healthy volunteers.


METHODS
IgA and IgG ANCAs were sought by indirect immunofluorescence with ethanol and formaldehyde-fixed human neutrophil preparations as the substrate. Enzyme-linked immunosorbent assays were further performed for antigen characterization.


RESULTS
IgA ANCAs were observed in 60% and IgG ANCAs in 10 (33%) of the patients. All patients with erythema elevatum diutinum had IgA ANCAs. IgA fluorescence in formaldehyde-fixed neutrophils was restricted to those from patients with erythema elevatum diutinum. Enzyme-linked immunosorbent assays disclosed no single predominant target, and antigens remained largely undetermined in erythema elevatum diutinum.


CONCLUSIONS
The ANCAs, particularly of IgA class, may prove to be a helpful paraclinical marker in erythema elevatum diutinum and an interesting perspective for understanding the pathophysiology of the disease. The nature of the unidentified targets and the pathogenicity of ANCAs, however, remain to be assessed.
Dermatology- Internal Medicine Department, Pitié-Salpêtrière Hospital, Paris, France.
Nakhlé
N
Ayoub
Jean-Luc
JL
Charuel
Marie-Claude
MC
Diemert
Stéphane
S
Barete
Marc
M
André
Jean-Paul
JP
Fermand
Jean-Charles
JC
Piette
Camille
C
Francès
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D016022:Case-Control Studies; D004890:Erythema / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017511:Pyoderma Gangrenosum / Q000276:immunology; D017445:Skin Diseases, Vascular / Q000276:immunology*; D016463:Sweet Syndrome / Q000276:immunology
D019268:Antibodies, Antineutrophil Cytoplasmic; D007070:Immunoglobulin A; D007074:Immunoglobulin G