Autoantibodies to the high-affinity IgE receptor in children with chronic urticaria.
BACKGROUND
Chronic urticaria (CU) in childhood remains a challenge for investigation, and its etiology is largely unknown. Autoantibodies to the high-affinity IgE receptor (FcepsilonRI) are believed to play a role in the pathogenesis of this disease in adults.


OBJECTIVE
To determine the prevalence of autoantibodies to FcepsilonRIalpha on basophils in children with CU vs atopic eczema dermatitis syndrome (AEDS).


METHODS
Eighty children with CU were compared with 38 children with AEDS. In addition to complete blood cell counts and total IgE measurements, CAP-RASTs to egg, codfish, soy, milk, and peanut were performed. Stool samples were examined for parasites, and autologous serum skin testing and a functional anti-FcepsilonRIalpha assay were conducted to detect autoantibodies.


RESULTS
No significant differences were observed between children with CU and controls in mean basophil or eosinophil counts. Twenty (26%) of 77 children with CU and 31 (82%) of 38 with AEDS had positive CAP-RAST results (P < .001). Only 2.5% of the children with CU and 0% with AEDS had stool samples positive for parasites (P = .005). Anti-FcepsilonRIalpha autoantibodies were positive in 37 (47%) of 78 children with CU and in none of 33 with AEDS. Non-IgG histamine-releasing factors were found in 10 (13%) of 78 children with CU.


CONCLUSIONS
Children have a similar prevalence of autoantibodies to the FcepsilonRIalpha as has been previously published for adults. Few have type I allergies, and parasite infestation is also uncommon. Further studies are required to investigate the predictive value of the autoantibodies in these children with respect to clinical profile, requirements for medications other than antihistamines, and remission rates.
Allergy and Dermatology Clinic, Red Cross Children's Hospital, School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa.
George
G
Du Toit
Ruth
R
Prescott
Patricia
P
Lawrence
Asmah
A
Johar
Geraldine
G
Brown
Eugene G
EG
Weinberg
Cassim
C
Motala
Paul C
PC
Potter
D000293:Adolescent; D000328:Adult; D000818:Animals; D017164:Ascaris lumbricoides / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001491:Basophils / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D003876:Dermatitis, Atopic / Q000276:immunology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D017455:Receptors, IgE / Q000276:immunology* / Q000378:metabolism*; D014581:Urticaria / Q000097:blood* / Q000276:immunology*
D001323:Autoantibodies; C475664:FCER1A protein, human; D017455:Receptors, IgE