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206 Allergenicity of the storage mite, Tyrophagus putrescentiae, and the neotropical dust mite, Blomia tropicalis
190 Abstracts
206
J ALLERGY
EVALUATION OF DERMESTID SENSITIVITY IN MUSEUM PERSONNEL. S. M.D.. A. Rohr... 13.B G.. &&, Los Angeles, CA. Nine museum personnel (39.9 + 9.6 years of age) with history of exposure to dermestid (D) beetles were assessedas to their sensitivity to the insect. Documentedreactions included immediate wheezing, coughing, watery eyes, sneezing and dermatitis. The average exposure time as 17.2 rt 9.7 years to the D beetle. Nine personnel (4 with negative history and 5 with positive history of beetle reactions) and five control subjects with atopic diseasewere skin tested to the beetle. The skin test panel consistedof D defatted and nondefatted exoskeleton, defatted adult beetle, defattcd larvae, house dust mite (farinae). grass mix, histamine control and negative control. The tests were applied with a Multi-test to the forearm. A test was consideredpositive if the wheal was equal to or greater than histamine control. All control subjects did not react to the D tests. None of the four personnel with a negative history for beetle reaction reacted to the D tests. One reacted to housedust and another to grass mix. Of the five personnel with a positive history, 4/5 had a positive skin test reaction to non-defatted exoskeleton, 2/5 reacted to defatted adult beetle, l/S reacted to defatted larvae, 3/S reacted to defatted exoskeleton. None of the personnel had an anaphylactic reaction during the test. In summary, the exoskeleton appears to be the most antigenic component of the D beetle. In conclusion, prevalence of D hypersensitivity among museum personnel may be determined through skin testing.
207
ALLERGENICIn OF THE STORAGEMITE,
208
C!IN. IMMUl\rOL. JANUARY 1997
Extreme environmental (heat, cold) and laboratory (PM. processing) conditions may denature allergens in household dust specimens. In this study, we examined the immunoreactivity of m 1. Der f 1 and w in buffer extracts of dust subjected to varying freeze-thaw (FT) and pH conditions and dust exposed to heat and carpet additives. Dust from 10 homes (lo-120 grams) was sieved (mesh 50), extracted with borate-buffered saline (18 hrs, 100 mg dust/2 ml, 23C), centrifuged and analyzed for allergen using monoclonal antibody-based immunoenzymetric assays (JACI 8Q:184, 1987), Intra-assay precision was 29% CV (n=lO assays) and inter-assay variation (5 extracts in 22 assays) was 218% CV. The rate of allergen extraction was rapid (>99% maximum allergen in solution by 1 hr, 4.5-44 q/ml range). Immunoreactivity of dust mite allergen was not altered by repeated ms (<5% difference; 0 to 20 FTs of extract) or extreme heat (dust in direct Summer sun, 5 days). Dust containing 10 ug m f 1 and 55 ug u per gram was sprinkled onto a new pre-vacuumed low shag carpet (500 mg/square ft). Dust recovery was 25%. Various carpet additives (3% tannic acid, Carpet Fresh, Arm/Hammer freshner, Love My Carpet, Johnsons’ and Pond’s baby powder) were layered onto separate dust-aeated squares. The final pH of extracted dust varied from pH 6 (Pond’s powder) to 10 (Arm/Hammer). Tannic acid (Control Products) was the only additive that ablated immunoreactive Derfl and m and reduced detectable w by 54%. In conclusion, dust mite and cat group I allergens are stable both in dust and laboratory extracts and can be reproducibly quantitated in specimens that have been subjected to variable heat, repeated freeze-thawing and common household camet additives.
I;ROSS-REACTIVITY
AMONG
de-
l&p& of &ls study &as to evaluate the antlgeniclty and allergenic&y of the mites, &I& trooicalis
0 we FernLuis R. Catabdlo. M.D.. Riu &&w. M.D., Cartagena, Colombia and Tampa, Florida Sera were collected from 77 atopic subjects from Cartagena, Colombia who had a positive prick skin test (2 3 mm) to either Dermatophagoides farinae (Df)
S
from 14 BT-sensitlve asthmatic patients and 24 ‘W-sensitive farmers wem used to evaluate the allergenlcity of the mite extracts. Extract prepared from TP contained 18+ antigens; 6 bound IgB when reacted with the Tp RAST positive sera. Individual sera showed IgE binding to 1 to 6 allergens; 75% of the 24 sera showed binding to at least 3 different TP allergens. BT was the source of at least 18 different antigens. Individual asthmatic patients’ sera showed circulating IgE directed at I to 8 allergens; 60% showed binding to 4 or more allergens. Hetemlogous ClE demonstrated that BT and TP extracts, prepared with mite bodies, shared 3 antigens. BT extract shared 1 antigen with extract prepared with TP feces. BT shared 4 antigens with DF and 2 with DP, while TF shared 2 antigens with DF. These tests aveal BT and TP are the sourcesof many antigens; several are important allergens. DF, DP, BT, and TP are largely the sourcesof species-specificantigens with cross-reactivity between spedes limited to a few antigens. It remains to be detennlned If any of these few crossreacting antigens are important allergens.
Blomia traatcalic. Derv
(94.8%)
OT Dermatophagoides
pternnyssinus
(90.9%). Twenty nine healthy volunteers with negative allergy histories and skin tests were used as controls. RAST and RAST inhibition assays were used to study the prevalence of specific IgE to B 1om ia tropicalis (Bt), Lepidoglyphus destructor (Ld) and Df. RAST results were considered positive when sera bound 2 1% of the total counts (%TCB). Sixty nine atopic subjects (89.6%) were positive to Df. 66 (SSSS) to Et and 46 (59.7%) to Ld. Regression analysis of the
RAST results gave the following correlation coefficients: Df vs. Bt, r=O.59; Df vs. Ld. ~0.44; and Et vs. Ld, r=0.52. RAST inhibition assays with ;! serum pool of 11 individuals highly allergic to all ? mites (mean specific IgE to all mites 5 18.2% TCB) demonstrated considerable cross-reactivity bccwecn Bt and Ld. and moderate cross-reactivity between n.f and the glycyphagid
mites, Bt and Ld.
A previous study showed that Df and B I arc important allergens environmental in Cartagena. The results of the present investigation support these findings and demonstrate that Ld is also an important source of allergens and that Et, Df and L d possess unique as well as common allergens.
206
J ALLERGY
EVALUATION OF DERMESTID SENSITIVITY IN MUSEUM PERSONNEL. S. M.D.. A. Rohr... 13.B G.. &&, Los Angeles, CA. Nine museum personnel (39.9 + 9.6 years of age) with history of exposure to dermestid (D) beetles were assessedas to their sensitivity to the insect. Documentedreactions included immediate wheezing, coughing, watery eyes, sneezing and dermatitis. The average exposure time as 17.2 rt 9.7 years to the D beetle. Nine personnel (4 with negative history and 5 with positive history of beetle reactions) and five control subjects with atopic diseasewere skin tested to the beetle. The skin test panel consistedof D defatted and nondefatted exoskeleton, defatted adult beetle, defattcd larvae, house dust mite (farinae). grass mix, histamine control and negative control. The tests were applied with a Multi-test to the forearm. A test was consideredpositive if the wheal was equal to or greater than histamine control. All control subjects did not react to the D tests. None of the four personnel with a negative history for beetle reaction reacted to the D tests. One reacted to housedust and another to grass mix. Of the five personnel with a positive history, 4/5 had a positive skin test reaction to non-defatted exoskeleton, 2/5 reacted to defatted adult beetle, l/S reacted to defatted larvae, 3/S reacted to defatted exoskeleton. None of the personnel had an anaphylactic reaction during the test. In summary, the exoskeleton appears to be the most antigenic component of the D beetle. In conclusion, prevalence of D hypersensitivity among museum personnel may be determined through skin testing.
207
ALLERGENICIn OF THE STORAGEMITE,
208
C!IN. IMMUl\rOL. JANUARY 1997
Extreme environmental (heat, cold) and laboratory (PM. processing) conditions may denature allergens in household dust specimens. In this study, we examined the immunoreactivity of m 1. Der f 1 and w in buffer extracts of dust subjected to varying freeze-thaw (FT) and pH conditions and dust exposed to heat and carpet additives. Dust from 10 homes (lo-120 grams) was sieved (mesh 50), extracted with borate-buffered saline (18 hrs, 100 mg dust/2 ml, 23C), centrifuged and analyzed for allergen using monoclonal antibody-based immunoenzymetric assays (JACI 8Q:184, 1987), Intra-assay precision was 29% CV (n=lO assays) and inter-assay variation (5 extracts in 22 assays) was 218% CV. The rate of allergen extraction was rapid (>99% maximum allergen in solution by 1 hr, 4.5-44 q/ml range). Immunoreactivity of dust mite allergen was not altered by repeated ms (<5% difference; 0 to 20 FTs of extract) or extreme heat (dust in direct Summer sun, 5 days). Dust containing 10 ug m f 1 and 55 ug u per gram was sprinkled onto a new pre-vacuumed low shag carpet (500 mg/square ft). Dust recovery was 25%. Various carpet additives (3% tannic acid, Carpet Fresh, Arm/Hammer freshner, Love My Carpet, Johnsons’ and Pond’s baby powder) were layered onto separate dust-aeated squares. The final pH of extracted dust varied from pH 6 (Pond’s powder) to 10 (Arm/Hammer). Tannic acid (Control Products) was the only additive that ablated immunoreactive Derfl and m and reduced detectable w by 54%. In conclusion, dust mite and cat group I allergens are stable both in dust and laboratory extracts and can be reproducibly quantitated in specimens that have been subjected to variable heat, repeated freeze-thawing and common household camet additives.
I;ROSS-REACTIVITY
AMONG
de-
l&p& of &ls study &as to evaluate the antlgeniclty and allergenic&y of the mites, &I& trooicalis
0 we FernLuis R. Catabdlo. M.D.. Riu &&w. M.D., Cartagena, Colombia and Tampa, Florida Sera were collected from 77 atopic subjects from Cartagena, Colombia who had a positive prick skin test (2 3 mm) to either Dermatophagoides farinae (Df)
S
from 14 BT-sensitlve asthmatic patients and 24 ‘W-sensitive farmers wem used to evaluate the allergenlcity of the mite extracts. Extract prepared from TP contained 18+ antigens; 6 bound IgB when reacted with the Tp RAST positive sera. Individual sera showed IgE binding to 1 to 6 allergens; 75% of the 24 sera showed binding to at least 3 different TP allergens. BT was the source of at least 18 different antigens. Individual asthmatic patients’ sera showed circulating IgE directed at I to 8 allergens; 60% showed binding to 4 or more allergens. Hetemlogous ClE demonstrated that BT and TP extracts, prepared with mite bodies, shared 3 antigens. BT extract shared 1 antigen with extract prepared with TP feces. BT shared 4 antigens with DF and 2 with DP, while TF shared 2 antigens with DF. These tests aveal BT and TP are the sourcesof many antigens; several are important allergens. DF, DP, BT, and TP are largely the sourcesof species-specificantigens with cross-reactivity between spedes limited to a few antigens. It remains to be detennlned If any of these few crossreacting antigens are important allergens.
Blomia traatcalic. Derv
(94.8%)
OT Dermatophagoides
pternnyssinus
(90.9%). Twenty nine healthy volunteers with negative allergy histories and skin tests were used as controls. RAST and RAST inhibition assays were used to study the prevalence of specific IgE to B 1om ia tropicalis (Bt), Lepidoglyphus destructor (Ld) and Df. RAST results were considered positive when sera bound 2 1% of the total counts (%TCB). Sixty nine atopic subjects (89.6%) were positive to Df. 66 (SSSS) to Et and 46 (59.7%) to Ld. Regression analysis of the
RAST results gave the following correlation coefficients: Df vs. Bt, r=O.59; Df vs. Ld. ~0.44; and Et vs. Ld, r=0.52. RAST inhibition assays with ;! serum pool of 11 individuals highly allergic to all ? mites (mean specific IgE to all mites 5 18.2% TCB) demonstrated considerable cross-reactivity bccwecn Bt and Ld. and moderate cross-reactivity between n.f and the glycyphagid
mites, Bt and Ld.
A previous study showed that Df and B I arc important allergens environmental in Cartagena. The results of the present investigation support these findings and demonstrate that Ld is also an important source of allergens and that Et, Df and L d possess unique as well as common allergens.