Basophil phenotypes in chronic idiopathic urticaria in relation to disease activity and autoantibodies.
Potentially pathogenic IgG autoantibodies to IgE or its receptor, Fc epsilonRIalpha, have been detected in approximately 40% of chronic idiopathic urticaria (CIU) patients. CIU patients' basophils display distinct altered Fc epsilonRIalpha-mediated degranulation. CIU patients with basophil histamine release in response to polyclonal goat anti-human IgE > or = 10% are classified as CIU responders (CIU-R) and < 10% are CIU non-responders (CIU-NR). We compared the presence of autoantibodies to basophil degranulation phenotypes and to disease status (active or inactive). Sera were collected from non-CIU subjects and CIU subjects who participated in a longitudinal study of disease severity and had defined basophil degranulation phenotypes. Immunoenzymetric assays (IEMA) quantified IgG anti-Fc epsilonRIalpha and anti-IgE. IgG anti-Fc epsilonRIalpha antibody was detected in 57% of CIU-R (n=35), 55% of CIU-NR (n=29), and 57% of non-CIU subjects (n=23), whereas IgG anti-IgE was present in 43% of CIU-R, 45% of CIU-NR, and 30% of non-CIU subjects. Both the autoantibody levels and the functional basophil phenotype remained stable in subjects with active disease (n=16), whereas there was an enhancement in basophil function as subjects evolved into a state of remission (n=6), which appears independent of the presence of autoantibody. IEMAs detected a similar frequency of autoantibodies in CIU-R, CIU-NR, and non-CIU subjects. Basophil function may be independent of IEMA-detected autoantibodies.
Eckman
John A
JA
Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA.
Hamilton
Robert G
RG
Gober
Laura M
LM
Sterba
Patricia M
PM
Saini
Sarbjit S
SS
D001323:Autoantibodies / Q000097:blood*; D001491:Basophils / Q000276:immunology*; D016022:Case-Control Studies; D002908:Chronic Disease; D006801:Humans; D007124:Immunoenzyme Techniques; D007073:Immunoglobulin E / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood*; D008137:Longitudinal Studies; D010641:Phenotype; D017455:Receptors, IgE / Q000235:genetics / Q000276:immunology*; D012075:Remission, Spontaneous; D012720:Severity of Illness Index; D014581:Urticaria / Q000097:blood / Q000276:immunology*
D001323:Autoantibodies; C475664:FCER1A protein, human; D007074:Immunoglobulin G; D017455:Receptors, IgE; D007073:Immunoglobulin E