Comparative studies of functional and binding assays for IgG anti-Fc(epsilon)RIalpha (alpha-subunit) in chronic urticaria.
BACKGROUND
Recent data suggest that a subpopulation of patients with chronic urticaria have an autoimmune disorder that is caused by the presence of antibodies to the IgE receptor. The actual incidence of these antibodies is uncertain.


OBJECTIVE
We sought to assess the incidence of autoimmunity to the IgE receptor in patients with chronic urticaria and to compare functional and binding assays.


METHODS
We isolated skin mast cells and studied a large number of patient sera (68) for their ability to activate these cells and isolated basophils. We then compared the results with those obtained by immunoblotting using cloned alpha-subunit of the IgE receptor.


RESULTS
Sera from patients with chronic urticaria released significant histamine (> 15% of basal) on incubation with basophils (48%) and mast cells (46%). By immunoblotting we obtained positive results in 64% of subjects tested and also identified a small subpopulation that is active on cells but does not bind Fc(epsilon)RIalpha.


CONCLUSIONS
Our data suggest that approximately 45% to 50% of patients with chronic urticaria have a cutaneous autoimmune disorder. Immunoblotting may provide a rapid screening method for anti-Fc(epsilon)RIalpha detection in such patients.
Ferrer
M
M
Division of Pulmonary-Critical Care and Allergy-Immunology, Medical University of South Carolina, Charleston 29425, USA.
Kinét
J P
JP
Kaplan
A P
AP
D001323:Autoantibodies / Q000276:immunology*; D001491:Basophils / Q000378:metabolism; D002908:Chronic Disease; D006636:Histamine Release; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000276:immunology*; D008407:Mast Cells / Q000378:metabolism; D017455:Receptors, IgE / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D014581:Urticaria / Q000097:blood / Q000276:immunology*
D001323:Autoantibodies; D007074:Immunoglobulin G; D017455:Receptors, IgE; D011994:Recombinant Proteins