SERUM IGG AUTOANTIBODIES DIRECTED AGAINST THE A CHAIN OF FC-EPSILON-RI - A SELECTIVE MARKER AND PATHOGENETIC FACTOR FOR A DISTINCT SUBSET OF CHRONIC URTICARIA PATIENTS

Citation
E. Fiebiger et al., SERUM IGG AUTOANTIBODIES DIRECTED AGAINST THE A CHAIN OF FC-EPSILON-RI - A SELECTIVE MARKER AND PATHOGENETIC FACTOR FOR A DISTINCT SUBSET OF CHRONIC URTICARIA PATIENTS, The Journal of clinical investigation, 96(6), 1995, pp. 2606-2612
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Medicine, Research & Experimental
ISSN journal
0021-9738
Volume
96
Issue
6
Year of publication
1995
Pages
2606 - 2612
Database
ISI
SICI code
0021-9738(1995)96:6<2606:SIADAT>2.0.ZU;2-Y
Abstract
While it is well established that acute allergic urticaria is caused b y degranulation of skin mast cells occurring after allergen/IgE-depend ent cross-linking of high affinity IgE receptors (Fc epsilon RI), the pathophysiologic mechanisms operative in chronic urticaria (CU) are le ss well understood, Some evidence points to the existence of histamine -releasing activity in the serum of CU patients which possibly acts vi a triggering of Fc epsilon RI. In this study, we aimed to better chara cterize this anti-Fc epsilon RI alpha reactivity of CU patients using affinity-purified, IgE-depleted IgG fractions of such individuals (CU- IgG), Using immobilized, recombinant soluble Fc epsilon RI alpha as a reaction target for Western blot studies, we found that 12/32 (37%) CU -IgG serum samples exhibited IgG autoreactivity against Fc epsilon RI alpha. These findings were confirmed by experiments demonstrating that immunoblot-reactive, but not immunoblot-nonreactive, CU-IgG preparati ons precipitated the Fc epsilon RI alpha from Fc epsilon RI alpha gamm a-transfected cells, No anti-Fc epsilon RI alpha reactivity was observ ed in IgG fractions from atopic dermatitis (AD) patients (0/15) or hea lthy control individuals (CO: 0/15), As opposed to the selective occur rence of IgG anti-Fc epsilon RI alpha autoantibodies in CU patients, I gG anti-IgE antibodies were detected in all groups investigated (CU: 6 9%; AD: 73%; CO: 26%), While both types of autoantibodies can exhibit histamine-releasing properties, not all of the autoantibodies proved t o be functional in vitro, Our results indicate that the occurrence of IgG anti-Fc epsilon RI alpha reactivity defines an autoimmune-mediated subentity of CU and provide a basis for the development of new diagno stic procedures and, perhaps, therapeutic strategies for this disease.