1
64 House Dust Mite Population Growth and Allergen Production in Cultures Maintained at Different Temperatures L. G. Arlian, L. Yella, M. S. Morgan; Wright State University, Dayton, OH. RATIONALE: House dust mites are commercially cultured to produce materials to make extracts for research, diagnostic tests and immunother- apy. Culture conditions can influence the mite population growth and allergen production in cultured house dust mites. The purpose of our investigation was to determine how temperature influences the population growth and allergen content of cultured Dermatophagoides pteronyssinus. METHODS: D. pteronyssinus was cultured on comparable amounts of media at 20 and 25C and the mite densities and allergen concentrations of the cultures were determined at 2-week intervals until the culture media was depleted. RESULTS: At both temperatures, the mite population and allergen con- centrations increased exponentially. The mite population and Der p1 and Der p2 concentrations increased at faster rates and achieved higher levels in cultures at 25C compared to 20C. The peak mite population density at 25C was 1.8 times greater than that at 20C. The Der p1 concentrations in- creased faster than Der p2. At 10 weeks, whole cultures grown at 25C had 2.0 and 1.7 times more Der p1 and Der p2, respectively compared to cul- tures grown at 20C. The concentrations of Der p1 and Der p2 in pure mite bodies harvested from the cultures was 60% and 49% less than in whole cultures grown at 25C. CONCLUSION: Greater mite and allergen levels were achieved in cul- tures grown at 25C compared to 20C demonstrating the importance of tem- perature. Washing mite bodies harvested from cultures resulted in the loss of large amounts of the allergen present in the mature whole cultures. 65 Biological Activity of Recombinant Tropomyosins from Ascaris lumbricoides and Cockroach among Patients with Asthma and/ or Rhinitis from Brazil A. C. A. F. Sousa 1 , A. B. R. Santos 1 , M. C. R. Barbosa 1 , M. D. Chapman 2 , L. K. Arruda 1 ; 1 School of Medicine of Ribeirao Preto, Ribeirao Preto, BRAZIL, 2 Indoor Biotechnologies Inc, Charlottesville, VA. RATIONALE: Tropomyosins have been associated with IgE cross-reac- tivity among invertebrates, including shrimp, cockroach, mites and para- sites. We have reported the recombinant production of Ascaris lumbricoides tropomyosin. The aim of this study was to investigate whether recombinant A. lumbricoides tropomyosin has biological activity, and to compare reactivity to that of recombinant cockroach tropomyosin (rPer a 7). METHODS: Frequency of positive skin tests to tropomyosins from A. lumbricoides and Periplaneta americana (rPer a 7), expressed in Pichia pastoris, was evaluated in 36 cockroach allergic patients with asthma and/or rhinitis, aged 12 to 70 years-old. All patients presented positive skin tests to P. americana extract. Skin tests with recombinant allergens were carried out at 10 mcg/ml concentration. RESULTS: Positive skin tests to recombinant Ascaris tropomyosin and to rPer a 7 were found in 16(44%) and 19(53%) patients, respectively. All 16 patients with positive skin tests to Ascaris tropomyosin were also positive to rPer a 7. The median wheal diameter on skin test reactions to P. amer- icana extract, Ascaris tropomyosin and rPer a 7 were 5mm, 5mm and 5.5mm, respectively. There was an excellent correlation of wheal diame- ters on skin test reactions to Ascaris tropomyosin and to rPer a 7 (r50.86; p<0.0001). Six non-allergic control subjects presented negative skin reactions. No adverse reactions were observed on subjects who under- went skin testing. CONCLUSIONS: Recombinant A. lumbricoides tropomyosin showed good biological activity, comparable to that of rPer a 7 and of commercial P. americana extract. Skin tests with recombinant allergens could be safely performed in patients with asthma and/or rhinitis. 66 Extensive IgE Cross-reactivity towards Different US Ragweed Species L. H. Christensen, C. Hejl, H. Henmar, N. Johansen, H. Ipsen; ALK- Abello ´, Horsholm, DENMARK. RATIONALE: Ragweed is spreading throughout Europe at a tremendous pace and already ranks among the most common allergen sources in US. In Europe, there is only one dominant ragweed species whereas at least 25 dif- ferent species exist in North America. The extent of structural similarity between major allergens from these different US ragweed species is, how- ever, currently unknown. This raises the question whether patient’s IgE an- tibodies cross-react towards these different ragweed species. METHODS: Extracts were made from pollens of 10 different ragweed species - all of them naturally occurring in North America, including the five most wide spread ones. The cross-reactive properties of patient’s IgE-repertoires towards these ragweed species were assessed using an IgE inhibition assay. Pools of sera were tested in the full matrix i.e. towards all 10 ragweed species and single US patient sera (n~50) towards the 3 most widespread ones. RESULTS: Extensive IgE cross reactivity was observed between most species. The patients included in this study seemed to be primarily sensi- tized towards Ambrosia artimisiifolia as this species was able to completely inhibit all other species. CONCLUSIONS: Our results show a high degree of patient’s IgE cross reactivity towards different ragweed species indicating that common (cross reactive) epitopes exist among all these different ragweed species. Knowledge about IgE cross-reactivity patterns is pivotal when deciding which species to include in products used for diagnosis as well as for spe- cific immunotherapy. 67 Aeroallergen Sensitization Among Children with Respiratory Allergy in Ramathibodi Hospital, Bangkok N. Anantasit, W. Kamchaisatian, C. Direkwattanachai, W. Manuyakorn, S. Vilaiyuk, S. Benjaponpitak; Department of Pediatric Allergy/Immunol- ogy/Rheumatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, THAILAND. RATIONALE: Aeroallergens have been identified to play a major role in the pathogenesis of the allergic disease. We aim to evaluate the prevalence of aeroallergens sensitization in Thai children with respiratory allergy. METHODS: A retrospective review of skin prick test (SPT) results against common aeroallergens in Thailand was performed in Pediatric Allergy Clinic at Ramathibodi hospital during 2000-2009. The reaction was con- sidered to be positive if mean wheal diameter was at least 3 mm. greater than negative control. RESULTS: The data were from 793 children aged between 2-18 years old which found to have positive SPT in 564 patients (71.1%). The prevalence of aeroallergen sensitization were 73.8% for Dermatophagoides pteronys- sinus, Dermatophagoides farinae 70.7%, American cockroach 34.6%, German cockroach 25.4%, cat 23.8%, Bermuda grass 14.5%, dog 12.8%, carelessweed 8.7%, Cladosporium 8%, Aspergillus 1.8% and Alternaria 1.4%. Among the positive SPT group, there were 63.3% of pa- tients having allergic rhinitis (AR), 9.3% having asthma and 27.4 having both. There was no significant difference among diagnosis for each aeroal- lergen and for number of sensitized allergen. It was found to have more sensitization to Cladosporium and dog in girls (p50.043 and 0.015, respec- tively), and to Der f in boys (p50.001). Children less than five years old were significantly sensitized to Bermuda grass than older age (21.5% vs. 13.2%, p50.038). CONCLUSIONS: From our study, dust mite is still the most common aeroallergen in Thai allergic children. Different causative aeroallergen be- tween gender and age group should be concerned for proper environmental control in allergic children. J ALLERGY CLIN IMMUNOL VOLUME 125, NUMBER 2 Abstracts AB17 SATURDAY

Aeroallergen Sensitization Among Children with Respiratory Allergy in Ramathibodi Hospital, Bangkok

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Page 1: Aeroallergen Sensitization Among Children with Respiratory Allergy in Ramathibodi Hospital, Bangkok

J ALLERGY CLIN IMMUNOL

VOLUME 125, NUMBER 2

Abstracts AB17

SA

TU

RD

AY

64 House Dust Mite Population Growth and Allergen Production in

Cultures Maintained at Different TemperaturesL. G. Arlian, L. Yella, M. S. Morgan; Wright State University, Dayton,

OH.

RATIONALE: House dust mites are commercially cultured to produce

materials to make extracts for research, diagnostic tests and immunother-

apy. Culture conditions can influence the mite population growth and

allergen production in cultured house dust mites. The purpose of our

investigation was to determine how temperature influences the population

growth and allergen content of cultured Dermatophagoides pteronyssinus.

METHODS: D. pteronyssinus was cultured on comparable amounts of

media at 20 and 25C and the mite densities and allergen concentrations

of the cultures were determined at 2-week intervals until the culture media

was depleted.

RESULTS: At both temperatures, the mite population and allergen con-

centrations increased exponentially. The mite population and Der p1 and

Der p2 concentrations increased at faster rates and achieved higher levels

in cultures at 25C compared to 20C. The peak mite population density at

25C was 1.8 times greater than that at 20C. The Der p1 concentrations in-

creased faster than Der p2. At 10 weeks, whole cultures grown at 25C had

2.0 and 1.7 times more Der p1 and Der p2, respectively compared to cul-

tures grown at 20C. The concentrations of Der p1 and Der p2 in pure mite

bodies harvested from the cultures was 60% and 49% less than in whole

cultures grown at 25C.

CONCLUSION: Greater mite and allergen levels were achieved in cul-

tures grown at 25C compared to 20C demonstrating the importance of tem-

perature. Washing mite bodies harvested from cultures resulted in the loss

of large amounts of the allergen present in the mature whole cultures.

65 Biological Activity of Recombinant Tropomyosins from Ascarislumbricoides and Cockroach among Patients with Asthma and/or Rhinitis from Brazil

A. C. A. F. Sousa1, A. B. R. Santos1, M. C. R. Barbosa1, M. D. Chapman2,

L. K. Arruda1; 1School of Medicine of Ribeirao Preto, Ribeirao Preto,

BRAZIL, 2Indoor Biotechnologies Inc, Charlottesville, VA.

RATIONALE: Tropomyosins have been associated with IgE cross-reac-

tivity among invertebrates, including shrimp, cockroach, mites and para-

sites. We have reported the recombinant production of Ascaris

lumbricoides tropomyosin. The aim of this study was to investigate

whether recombinant A. lumbricoides tropomyosin has biological activity,

and to compare reactivity to that of recombinant cockroach tropomyosin

(rPer a 7).

METHODS: Frequency of positive skin tests to tropomyosins from A.lumbricoides and Periplaneta americana (rPer a 7), expressed in Pichia

pastoris, was evaluated in 36 cockroach allergic patients with asthma

and/or rhinitis, aged 12 to 70 years-old. All patients presented positive

skin tests to P. americana extract. Skin tests with recombinant allergens

were carried out at 10 mcg/ml concentration.

RESULTS: Positive skin tests to recombinant Ascaris tropomyosin and to

rPer a 7 were found in 16(44%) and 19(53%) patients, respectively. All 16

patients with positive skin tests to Ascaris tropomyosin were also positive

to rPer a 7. The median wheal diameter on skin test reactions to P. amer-

icana extract, Ascaris tropomyosin and rPer a 7 were 5mm, 5mm and

5.5mm, respectively. There was an excellent correlation of wheal diame-

ters on skin test reactions to Ascaris tropomyosin and to rPer a 7

(r50.86; p<0.0001). Six non-allergic control subjects presented negative

skin reactions. No adverse reactions were observed on subjects who under-

went skin testing.

CONCLUSIONS: Recombinant A. lumbricoides tropomyosin showed

good biological activity, comparable to that of rPer a 7 and of commercial

P. americana extract. Skin tests with recombinant allergens could be safely

performed in patients with asthma and/or rhinitis.

66 Extensive IgE Cross-reactivity towards Different US RagweedSpecies

L. H. Christensen, C. Hejl, H. Henmar, N. Johansen, H. Ipsen; ALK-

Abello, Horsholm, DENMARK.

RATIONALE: Ragweed is spreading throughout Europe at a tremendous

pace and already ranks among the most common allergen sources in US. In

Europe, there is only one dominant ragweed species whereas at least 25 dif-

ferent species exist in North America. The extent of structural similarity

between major allergens from these different US ragweed species is, how-

ever, currently unknown. This raises the question whether patient’s IgE an-

tibodies cross-react towards these different ragweed species.

METHODS: Extracts were made from pollens of 10 different ragweed

species - all of them naturally occurring in North America, including the

five most wide spread ones.

The cross-reactive properties of patient’s IgE-repertoires towards these

ragweed species were assessed using an IgE inhibition assay.

Pools of sera were tested in the full matrix i.e. towards all 10 ragweed

species and single US patient sera (n~50) towards the 3 most widespread

ones.

RESULTS: Extensive IgE cross reactivity was observed between most

species. The patients included in this study seemed to be primarily sensi-

tized towards Ambrosia artimisiifolia as this species was able to completely

inhibit all other species.

CONCLUSIONS: Our results show a high degree of patient’s IgE cross

reactivity towards different ragweed species indicating that common (cross

reactive) epitopes exist among all these different ragweed species.

Knowledge about IgE cross-reactivity patterns is pivotal when deciding

which species to include in products used for diagnosis as well as for spe-

cific immunotherapy.

67 Aeroallergen Sensitization Among Children with RespiratoryAllergy in Ramathibodi Hospital, Bangkok

N. Anantasit, W. Kamchaisatian, C. Direkwattanachai, W. Manuyakorn,

S. Vilaiyuk, S. Benjaponpitak; Department of Pediatric Allergy/Immunol-

ogy/Rheumatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol

University, Bangkok, THAILAND.

RATIONALE: Aeroallergens have been identified to play a major role in

the pathogenesis of the allergic disease. We aim to evaluate the prevalence

of aeroallergens sensitization in Thai children with respiratory allergy.

METHODS: A retrospective review of skin prick test (SPT) results against

common aeroallergens in Thailand was performed in Pediatric Allergy

Clinic at Ramathibodi hospital during 2000-2009. The reaction was con-

sidered to be positive if mean wheal diameter was at least 3 mm. greater

than negative control.

RESULTS: The data were from 793 children aged between 2-18 years old

which found to have positive SPT in 564 patients (71.1%). The prevalence

of aeroallergen sensitization were 73.8% for Dermatophagoides pteronys-sinus, Dermatophagoides farinae 70.7%, American cockroach 34.6%,

German cockroach 25.4%, cat 23.8%, Bermuda grass 14.5%, dog

12.8%, carelessweed 8.7%, Cladosporium 8%, Aspergillus 1.8% and

Alternaria 1.4%. Among the positive SPT group, there were 63.3% of pa-

tients having allergic rhinitis (AR), 9.3% having asthma and 27.4 having

both. There was no significant difference among diagnosis for each aeroal-

lergen and for number of sensitized allergen. It was found to have more

sensitization to Cladosporium and dog in girls (p50.043 and 0.015, respec-

tively), and to Der f in boys (p50.001). Children less than five years old

were significantly sensitized to Bermuda grass than older age (21.5% vs.

13.2%, p50.038).

CONCLUSIONS: From our study, dust mite is still the most common

aeroallergen in Thai allergic children. Different causative aeroallergen be-

tween gender and age group should be concerned for proper environmental

control in allergic children.