Autoantibodies to early endosome antigen (EEA1) produce a staining pattern resembling cytoplasmic anti-neutrophil cytoplasmic antibodies (C-ANCA).
Autoantibodies to EEA1 have been described in patients with neurological diseases, subacute cutaneous lupus and a variety of other conditions, including a patient with Wegener's granulomatosis (WG). EEA1 is a hydrophilic peripheral membrane protein transiently associated with the cytoplasmic face of early endosomes. Antibodies to EEA1 produce a staining pattern that resembles the C-ANCA pattern produced by anti-proteinase 3 (PR3) antibodies in WG sera. Co-localization studies show incomplete overlap of the staining produced by anti-EEA1 with anti-PR3. We showed that 0/40 unselected sera, from a cohort of WG patients and antibodies to PR3, reacted with EEA1. In addition, 1/15 sera that have a C-ANCA staining pattern but do not react with PR3 in an ELISA, immunoprecipitated the recombinant EEA1 protein. We conclude that although antibodies to EEA1 produce a staining pattern that resembles anti-PR3 and C-ANCA, antibodies to EEA1 in WG are rare. However, some C-ANCA+ sera that do not react with PR3 may contain EEA1 autoantibodies.
Selak
S
S
Faculty of Medicine, University of Calgary, Calgary, Canada.
Woodman
R C
RC
Fritzler
M J
MJ
D000818:Animals; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect; D014890:Granulomatosis with Polyangiitis / Q000097:blood / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D008565:Membrane Proteins / Q000276:immunology*; D053146:Myeloblastin; D009504:Neutrophils / Q000276:immunology; D011233:Precipitin Tests / Q000379:methods; D011817:Rabbits; D012697:Serine Endopeptidases / Q000276:immunology; D012967:Sodium Dodecyl Sulfate; D013194:Staining and Labeling; D014407:Tumor Cells, Cultured; D033921:Vesicular Transport Proteins
D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies; D001324:Autoantigens; D008565:Membrane Proteins; D033921:Vesicular Transport Proteins; C093846:early endosome antigen 1; D012967:Sodium Dodecyl Sulfate; D012697:Serine Endopeptidases; D053146:Myeloblastin