500 Epidemiology of Mosquito Bite Allergy in the Centre of Allergy and Clinical Immunology of Monterrey, Mexico

A. Arias-Cruz, E. Avitia-Valenzuela, S. N. González-Díaz, G. Galindo-

Rodríguez; Allergy and Clinical Immunology, University Hospital,

Monterrey, N.L., MEXICO.

RATIONALE: To know the prevalence and type of allergic reactions to

mosquito bite in our population, we performed a descriptive cross sec-

tional study.

METHODS: 482 patients ranged in age from 2 to 58 years referred to our

centre were evaluated. A questionnaire on mosquito bite reactions history

was applied to the adult patients and the parents’ children. Additionally,

skin prick test (SPT) were performed in all of these subjects with common

aeroallergens of the northeastern of Mexico and whole body extract of

Aedes aeigypti (a common mosquito species in Mexico).

RESULTS: The mean age of the subjects was 18.5 ± 14.8 years. 257

(53.3%) were female. 307 (63.7%) were atopic with positive SPT to at

least one aeroallergen. 395 (82%) had a positive history of local reactions

to mosquito bites, but only 12 (2.5%) presented large local reactions (8

were younger than 10 years). The most common local reactions included

erythema, itching, papules and small wheals. Only one patient (0.2%) had

history of systemic reaction characterized by urticaria. SPT to mosquito

was positive in 85 subjects (17.6%) and 78 of them had history of local

reactions (p= 0.24), but only 3 of them were large. There were not differ-

ences in the sensitization to mosquito between atopic and no atopic

subject (p> .05).

CONCLUSIONS: Local reactions to mosquito bites are common and

sensitization to this insect is frequent in our population. In general, the

prevalence of large local reactions is relatively low, although it is greater

in children. Allergic systemic reactions seem to be rare.

Funding: UANL

501 Circulating Specific IgE to Gliadin Can be a Useful Marker forDiagnosing Wheat-Dependent Exercise-Induced Anaphylax-is Patients Among the Wheat-Sensitized Patients

J. Lee1, S. Yoon2, Y. Ye2, S. Kim2, H. Park2; 1Department of internal med-

icine, College of medicine, Hallym University, Chunchon, REPUBLIC

OF KOREA, 2Department of Allergy and Rheumatology, Ajou Univer-

sity School of Medicine, Suwon, REPUBLIC OF KOREA.

RATIONALE: Wheat is one of the common sensitizing food allergens to

cause food-dependent exercise-induced anaphylaxis in Korea. In pediatric

patients with wheat-induced anaphylaxis, circulating specific IgE was

detected. Exercise could increase serum gliadin level after taking wheat

flour containing foods. In this study, we evaluated serum specific IgE to

gliadin for the diagnosis of wheat-dependent exercise-induced anaphy-

laxis (WDEIA), and their binding characteristics were evaluated.

METHODS: Thirty-six adult subjects sensitized to wheat were enrolled;

26 were asymptomatic sensitizers and 6 had WDEIA. Specific IgE to wheat

flour and gliadin extracts were measured by ELISA. IgE immunoblot analy-

sis to both wheat and gliadin extracts were compared with or without sim-

ulated gastric and intestinal fluid incubation (SGF and SIF).

RESULTS: Among 6 WDEIA patients, only 3 (50%) had high specific

IgE to wheat, but 6 (100%) had high serum specific IgE to gliadin. How-

ever, in 26 asymptomatic subjects, 14 had high specific IgE to wheat but

no one had specific IgE to gliadin. All of 6 WDEIA patients had high IgE

binding signals to 50 kDa of gliadin extract on IgE immunoblot, which

could be suppressed by SGF, but minimal inhibitions were noted by SIF

incubation.

CONCLUSIONS: Circulating specific IgE to gliadin can be applied as a

sensitive marker for diagnosing adult WDEIA patients.

Funding: Korea augricultural R&D promotion center

502 Anaphylaxis in Children in Central Israel

B. Garty, V. Hoffer, N. Marcus, O. Schoerman, Y. Levy, Y. Finkelstein, Y.

L. Danon; Schneider Children Medical Center of Israel, Petah Tikva,

ISRAEL.

RATIONALE: Despite being a medical emergency, little is known about

the causes and clinical features of anaphylaxis in children in Israel.METHODS: We evaluated events of anaphylaxis in children admitted to

our children’s hospital during a period of 12 years.

RESULTS: 92 children with anaphylaxis (50 boys and 42 girls), age

range 4 days to 18 years (mean 8.5 years) were admitted during the study

period; 43 children had atopic disorders (mainly asthma). Anaphylaxis

occurred at home in 52 children (54%) and in the medical institution in 24

children (26%). The main causes of anaphylaxis were food (39%) mainly

milk and nuts, medications (22%) and hymenoptera venoms (13%). Six-

teen patients had more than one episode of anaphylaxis, and except in one

case, did not use self-administered epinephrine injection(EpiPen). Seven

patients were admitted to intensive care unit. There were no fatalities.

CONCLUSIONS: Most cases of anaphylaxis in our series were caused

by food, particularly milk and nuts. The majority of our patients had only

one episode of anaphylaxis, therefore its prevention seemed to be almost

impossible. EpiPen was used only by one out of 16 patients who had more

than one episode of anaphylaxis, showing that the education for its use

might have been insufficient.

503 Purification of Insect Venom Proteins

D. R. Hoffman; Pathology and Laboratory Medicine, Brody School of

Medicine, Greenville, NC.

RATIONALE: Some of the chromatographic materials used in the orig-

inal descriptions of purification of insect venom proteins are no longer

available.

METHODS: A selection of currently available chromatographic materials

were evaluated for the purification of fire ant and yellowjacket venom

proteins. Separations and purity were monitored by SDS-PAGE.

RESULTS: High performance gel filtration materials based on silica,

agarose or polyacrylamide all interacted with materials including both

proteins and peptides in the venoms, preventing separation based upon

size. High salt concentrations reduced, but did not eliminate these inter-

actions. A 1.7meter column of Sephadex G50F gave the best results in

acidic buffer containing 0.15M NaCl. Sephadex G75 superfine columns

were extremely difficult to use with venoms. Excellent cation-exchange

separations were obtained with Pharmacia Mono S and PolyLC polysul-

foethyl A columns. Other silica based cation exchangers did not work as

well. The use of traditional reversed phase columns caused varying

degrees of denaturation. Perfusion chromatography columns Poros R

from Applied Bioscience and TSK Gel SuperODS from TosoHaas gave

good separations with preservation of immunoreactivity.

CONCLUSIONS: Many high performance gel filtration columns are

unsuitable for use with venom proteins; Sephadex remains the medium of

choice. Excellent cation-exchange columns and perfusion chromat-

ography columns are readily available.

Funding: Brody School of Medicine

S128 Abstracts J ALLERGY CLIN IMMUNOL

FEBRUARY 2006

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