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170 Comparison of guanine levels and mite allergen content in house dust samples
Abstracts
J ALLERGY CLIN IMMUNOL
225
VOLUME 97, NUMBER 1, PART 3
169
A Comparison of Monoclonal Antibody (mAb)-Capture and Der f 1-Capture ELISAs for Measurement of Dermatophagoides farinae (Der 39 I-Speclfic IgE. w xe,
171
P e a k E x p i r a t o r y Flow ( P E F ) variability a n d exposure to Dermatophagoides/arinae. M.K. O ' R o u r k e , Ph.D., S h a n Jin. Ph.D. a n d A. Atmowidiojo, M.S. Tucson, A Z USA. A previous study r e c r u i t e d a n d c h a r a c t e r i z e d a population representative of Pima County (AZ) e m p l o y e e s a n d t h e i r families. W e visited a subset of 269 h o u s e h o l d s a n d e v a l u a t e d c h a n g e s in daily symptoms, including P E F in 610 residents. R e s i d e n t s completed standard respiratory health questionnaires and w e r e prick t e s t e d with D. [arinae ( D F ) , 24 o t h e r antigens a n d controls. W e m e a s u r e d h o u s e dust m i t e c o n c e n t r a t i o n s in m u l t i p l e locations. D F was f o u n d in about half the homes sampled; w h e r e a s D. pteronyssinus was f o u n d in only 3 % of t h e homes. T i m e / a c t i v i t y diaries a n d mite c o n c e n t r a t i o n s w e r e used to calculate daily subject-exposure values. W e initially analyzed t h e s e d a t a using categorical a n d l i n e a r statistical m e t h o d s to i d e n t i f y t r e n d s a n d potential relationships. Certain population subgroups (children, c u r r e n t a n d f o r m e r smokers, elderly) exhibited significant relationships b e t w e e n P E F a n d m i t e exposure. W e realize t h a t s y m p t o m s including P E F are highly a u t o c o r r e l a t e d . R a n d o m Effect M o d e l s a c c o u n t for t h e a u t o c o r r e l a t i o n in symptom response, so R E M was used to e v a l u a t e P E F r e s p o n s e to m i t e exposure. Subject height, weight a n d age are i m p o r t a n t v a r i a b l e s r e l a t e d to P E F a n d always e n t e r t h e model. Skin test reactivity to D F also e n t e r s t h e m o d e l as a n i m p o r t a n t factor.
172
EUROGLYPHUS MAYNEI (Em) Skin Test Reactivity in Patients with Asthma and or
PhD, FER Simons, MD, Z Peng, MD, Winnipeg, Manitoba, Canada. Dee f I is a major antigen in Der f extract. Due to difficulty in obtaining large amounts of purified Derf I, measurement of Derf lspecific lgE is not commonly used. We developed 2 ELISAs for measurement of Der f I-specific IgE. In the mAb-capture ELISA, mlcroplates were coated with a mAb (6A8)" specific to Derf I, then sequentially incubated with a crude Derf extract, serum samples or a reference serum (1,000 U/mi), goat-anti human IgE, and rabbit antigoat lgG conjugate. In the conventional Der f I-capture assay, microplates coated with Der f I" were sequentially incubated with samples and the antibodies as in the mAb-capture ELISA. Both assays were inhibited by the crude Derf extract and had a sensitivity of 0.8 U/ml. Using the 2 ELISAs, serum DerfI-specific lgE was evaluated in 26 atopic patients with or without positive skin tests to Derf extract and in 15 healthy control subiects. The ELISA results were: Group No. Geom. X (U/ml) Positive % m.Ab-cap. Der-cap. mAb-eap. Der-cao. Skin test + patients 12 8.6 19.2 50 75 Skin test - patients 14 2.0 10.2 21 71 Controls 15 0 4.9 0 53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A significant difference was found between patients with positive skin tests and controls (p < 0.00) only when the measurement was performed by the mAb-capture ELISA, suggesting that this assay is more specific than the conventional assay. "Kindly provided by Dr. M. Chapman.
170
Comparison of Guanine Levels and Mite Allergen Content in House Dust Samples. RR Baker Pbl~. CB Arant BS. NT Rupp MD. Augusta, GA Reducing exposure to indoor allergens is a essential in the management of atopic asthma. Analysis of allergens in house dust samples in patient homes at the time of collection can facilitate early treatment of allergen sources and may make home assessment by health care personnel more feasible. ACAREX test kits (distributed by Fisons Corp., Bedford MA) semiquantitatively measure guanine, a component of mite feces. We examined the correlation of a semiquantitative assay for mites and a quantitative determination of group I house dust mite allergens (Derp I and DerfI) using two-site monoclonal antibody (Mab) ELISA assay to determine whether this detection method can be reliably used in patient homes. Fifty-six dust samples from the homes of seventeen pediatric asthmatic patients with skin test sensitivity to D. pteronnysinus and/or D.forinae were tested by both the ACAREX and double Mab techniques. A correlation coefficient of 0.S] was found using the Spearman rank order test (p<0.05). ACAREX guanine levels are expressed in a four-stage color scale which represent "negative" to "strongly positive" results. A comparison of groups showed significant differences in the median values (p < 0.03) of Class 0 (n = 22) and all other Classes (Class l, n = 22; Class 2, n = 10, and Class 3, n = 2). Only the values Classes 2 and 3 were not significantly different. In Class 2 and Class 3 all Der group 1 antigen levels were greater than 2000 ng/g dust. Sixty-seven percent of samples in Class 2 and 3 results had Der group I levels of greater than 10000 ng/g dust. ACAREX test results corrleate with quantitative Mab Der group I levels and the ACAREX classification may indicate the level of mite allergen exposure.
Rhinitis
in
Rio
de
Janeiro.
~ Geller
MDp
RE Esch PhD. E Fernandez.Caldas PhD, Rio de Janeiro, Brazil! Lenoir, NC! Tampa,Fl. The prevalence of allergic sensitization to Euroglyphus maynei (Em) has not been previously reported in Rio de Janeiro, Brazil. This study determined the skin test reactivity ¢o Em and compared it to that obtained with Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Dr), Blomia tropicalis (Bt) and Brazilian house dust (Bhd) extracts in i00 consecutive subjects with asthma and or rhinitis in the tropical coastal region of Brazil. There was a strong correlation between reactivity towards ~m and Dp as well as Em and Df. No unique reactors were found towards Em, however 3% reacted only to Bt and i% solely to Df. Dp, Df and Bt were sufficient to identify all reactors. The local incidence of mite atopy increased almost 10% in recent years and is currently ?~% among patients with asthma and or rhinitis in Rio de Janeiro, Domestic mites are the most important Brazilian aeroallergens.
J ALLERGY CLIN IMMUNOL
225
VOLUME 97, NUMBER 1, PART 3
169
A Comparison of Monoclonal Antibody (mAb)-Capture and Der f 1-Capture ELISAs for Measurement of Dermatophagoides farinae (Der 39 I-Speclfic IgE. w xe,
171
P e a k E x p i r a t o r y Flow ( P E F ) variability a n d exposure to Dermatophagoides/arinae. M.K. O ' R o u r k e , Ph.D., S h a n Jin. Ph.D. a n d A. Atmowidiojo, M.S. Tucson, A Z USA. A previous study r e c r u i t e d a n d c h a r a c t e r i z e d a population representative of Pima County (AZ) e m p l o y e e s a n d t h e i r families. W e visited a subset of 269 h o u s e h o l d s a n d e v a l u a t e d c h a n g e s in daily symptoms, including P E F in 610 residents. R e s i d e n t s completed standard respiratory health questionnaires and w e r e prick t e s t e d with D. [arinae ( D F ) , 24 o t h e r antigens a n d controls. W e m e a s u r e d h o u s e dust m i t e c o n c e n t r a t i o n s in m u l t i p l e locations. D F was f o u n d in about half the homes sampled; w h e r e a s D. pteronyssinus was f o u n d in only 3 % of t h e homes. T i m e / a c t i v i t y diaries a n d mite c o n c e n t r a t i o n s w e r e used to calculate daily subject-exposure values. W e initially analyzed t h e s e d a t a using categorical a n d l i n e a r statistical m e t h o d s to i d e n t i f y t r e n d s a n d potential relationships. Certain population subgroups (children, c u r r e n t a n d f o r m e r smokers, elderly) exhibited significant relationships b e t w e e n P E F a n d m i t e exposure. W e realize t h a t s y m p t o m s including P E F are highly a u t o c o r r e l a t e d . R a n d o m Effect M o d e l s a c c o u n t for t h e a u t o c o r r e l a t i o n in symptom response, so R E M was used to e v a l u a t e P E F r e s p o n s e to m i t e exposure. Subject height, weight a n d age are i m p o r t a n t v a r i a b l e s r e l a t e d to P E F a n d always e n t e r t h e model. Skin test reactivity to D F also e n t e r s t h e m o d e l as a n i m p o r t a n t factor.
172
EUROGLYPHUS MAYNEI (Em) Skin Test Reactivity in Patients with Asthma and or
PhD, FER Simons, MD, Z Peng, MD, Winnipeg, Manitoba, Canada. Dee f I is a major antigen in Der f extract. Due to difficulty in obtaining large amounts of purified Derf I, measurement of Derf lspecific lgE is not commonly used. We developed 2 ELISAs for measurement of Der f I-specific IgE. In the mAb-capture ELISA, mlcroplates were coated with a mAb (6A8)" specific to Derf I, then sequentially incubated with a crude Derf extract, serum samples or a reference serum (1,000 U/mi), goat-anti human IgE, and rabbit antigoat lgG conjugate. In the conventional Der f I-capture assay, microplates coated with Der f I" were sequentially incubated with samples and the antibodies as in the mAb-capture ELISA. Both assays were inhibited by the crude Derf extract and had a sensitivity of 0.8 U/ml. Using the 2 ELISAs, serum DerfI-specific lgE was evaluated in 26 atopic patients with or without positive skin tests to Derf extract and in 15 healthy control subiects. The ELISA results were: Group No. Geom. X (U/ml) Positive % m.Ab-cap. Der-cap. mAb-eap. Der-cao. Skin test + patients 12 8.6 19.2 50 75 Skin test - patients 14 2.0 10.2 21 71 Controls 15 0 4.9 0 53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A significant difference was found between patients with positive skin tests and controls (p < 0.00) only when the measurement was performed by the mAb-capture ELISA, suggesting that this assay is more specific than the conventional assay. "Kindly provided by Dr. M. Chapman.
170
Comparison of Guanine Levels and Mite Allergen Content in House Dust Samples. RR Baker Pbl~. CB Arant BS. NT Rupp MD. Augusta, GA Reducing exposure to indoor allergens is a essential in the management of atopic asthma. Analysis of allergens in house dust samples in patient homes at the time of collection can facilitate early treatment of allergen sources and may make home assessment by health care personnel more feasible. ACAREX test kits (distributed by Fisons Corp., Bedford MA) semiquantitatively measure guanine, a component of mite feces. We examined the correlation of a semiquantitative assay for mites and a quantitative determination of group I house dust mite allergens (Derp I and DerfI) using two-site monoclonal antibody (Mab) ELISA assay to determine whether this detection method can be reliably used in patient homes. Fifty-six dust samples from the homes of seventeen pediatric asthmatic patients with skin test sensitivity to D. pteronnysinus and/or D.forinae were tested by both the ACAREX and double Mab techniques. A correlation coefficient of 0.S] was found using the Spearman rank order test (p<0.05). ACAREX guanine levels are expressed in a four-stage color scale which represent "negative" to "strongly positive" results. A comparison of groups showed significant differences in the median values (p < 0.03) of Class 0 (n = 22) and all other Classes (Class l, n = 22; Class 2, n = 10, and Class 3, n = 2). Only the values Classes 2 and 3 were not significantly different. In Class 2 and Class 3 all Der group 1 antigen levels were greater than 2000 ng/g dust. Sixty-seven percent of samples in Class 2 and 3 results had Der group I levels of greater than 10000 ng/g dust. ACAREX test results corrleate with quantitative Mab Der group I levels and the ACAREX classification may indicate the level of mite allergen exposure.
Rhinitis
in
Rio
de
Janeiro.
~ Geller
MDp
RE Esch PhD. E Fernandez.Caldas PhD, Rio de Janeiro, Brazil! Lenoir, NC! Tampa,Fl. The prevalence of allergic sensitization to Euroglyphus maynei (Em) has not been previously reported in Rio de Janeiro, Brazil. This study determined the skin test reactivity ¢o Em and compared it to that obtained with Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Dr), Blomia tropicalis (Bt) and Brazilian house dust (Bhd) extracts in i00 consecutive subjects with asthma and or rhinitis in the tropical coastal region of Brazil. There was a strong correlation between reactivity towards ~m and Dp as well as Em and Df. No unique reactors were found towards Em, however 3% reacted only to Bt and i% solely to Df. Dp, Df and Bt were sufficient to identify all reactors. The local incidence of mite atopy increased almost 10% in recent years and is currently ?~% among patients with asthma and or rhinitis in Rio de Janeiro, Domestic mites are the most important Brazilian aeroallergens.