Evaluation of serum s-IgE/total IgE ratio in predicting clinical response to allergen-specific immunotherapy.
BACKGROUND
To date, no predictive tests for the clinical response to allergen-specific immunotherapy (ASI) are available. Therefore an in vivo or in vitro test would be of great value.


OBJECTIVE
We sought to evaluate pretreatment parameters used in diagnosing allergic rhinitis and determining serum specific IgE (s-IgE) levels, serum total IgE (t-IgE) levels, and blood eosinophil counts and to identify whether can be used to predict clinical improvement in monosensitized patients with allergic rhinitis with or without asthma treated with immunotherapy.


METHODS
We analyzed 279 patients who had undergone 4 years of ASI administered either by means of the subcutaneous immunotherapy (76 patients) or sublingual immunotherapy (203 patients) routes. Serum t-IgE and s-IgE levels, blood eosinophil counts, and serum s-IgE/t-IgE ratios were calculated and tested for correlation with clinical response to ASI. Receiver operating characteristic curves were determined. Predicted probabilities and predictive areas under the curve were calculated.


RESULTS
The clinical response to ASI was effective in 145 (52.0%) of 279 total patients, 42 (55.2%) of 76 patients treated with subcutaneous immunotherapy, and 103 (50.7%) of 203 patients treated with sublingual immunotherapy. A significant correlation was found between the serum s-IgE/t-IgE ratio and the clinical response to ASI, with high ratios (>16.2) associated with an effective response. The sensitivity and specificity of the area under the curve of the ratio were higher than those of serum s-IgE and t-IgE alone.


CONCLUSIONS
The calculation of the serum s-IgE/t-IgE ratio for predicting the clinical response to ASI offers an advantage over measuring t-IgE and s-IgE levels in monosensitized patients for the following allergens: grass, Parietaria judaica, Olea europea, and house dust mite.
Di Lorenzo
Gabriele
G
Dipartimento di Medicina Clinica e delle Patologie Emergenti, Università degli Studi di Palermo, Palermo, Italy. dilo601@unipa.it
Mansueto
Pasquale
P
Pacor
Maria Luisa
ML
Rizzo
Manfredi
M
Castello
Francesco
F
Martinelli
Nicola
N
Ditta
Vito
V
Lo Bianco
Claudia
C
Leto-Barone
Maria Stefania
MS
D'Alcamo
Alberto
A
Di Fede
Gaetana
G
Rini
Giovam Battista
GB
Ditto
Anne Marie
AM
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D001772:Blood Cell Count; D003888:Desensitization, Immunologic; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology* / Q000628:therapy*; D012882:Skin Tests; D013147:Spirometry; D016896:Treatment Outcome; D055815:Young Adult
D000485:Allergens; D007073:Immunoglobulin E