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Rob C Aalberse - One of the best experts on this subject based on the ideXlab platform.
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false Positive Skin prick test responses to commercially available dog dander extracts caused by contamination with house dust mite dermatophagoides pteronyssinus allergens
The Journal of Allergy and Clinical Immunology, 1996Co-Authors: M J Van Der Veen, Melchior Mulder, A M Witteman, Rob C Aalberse, H M JansenAbstract:Abstract BACKGROUND: In an outpatient population, a high frequency of Positive Skin prick test responses to dog dander was found in the absence of detectable IgE to dog dander in the RAST. The majority of these patients were sensitized to house dust mites (Dermatophagoides pteronyssinus) and had no obvious dog-related allergic symptoms. These findings prompted us to investigate whether dog dander Skin test preparations are contaminated with house dust mite allergens in amounts sufficient to cause false-Positive Skin prick test responses in patients sensitized to house dust mites. METHODS: Antigen detection assays with monoclonal and polyclonal antibodies were used to determine concentrations of the major allergen Can f 1 from dog dander and the major allergens Der p 1 and Der p 2 from house dust mites in five commercially available dog dander Skin prick test preparations (A to E). RESULTS: Can f 1 concentrations varied for the different extracts (A: 170 μg/ml, B: 11.1 μg/ml, C: 13.3 μg/ml, D: 3.8 μg/ml, and E: 59.4 μg/ml). Der p 1 was detectable in all extracts (A: 33.4 ng/ml, B: 5.1 ng/ml, C: 29.6 ng/ml, D: 0.4 ng/ml, and E: 1.9 ng/ml), and Der p 2 was detectable in some of the commercially available dog dander Skin prick test preparations tested (A: 31.3 ng/ml, B: 3.0 ng/ml, and C: 7.5 ng/ml). The median house dust mite threshold in the Skin prick test was found to be 5.8 ng/ml of Der p 1 (range, 3.5 to 20.8 ng/ml) in nine patients tested. CONCLUSION: Contamination of commercially available dog dander Skin prick test preparations with the major allergens (Der p 1 and Der p 2) of the house dust mite (D. pteronyssinus) was demonstrated. These contaminations cause false-Positive responses to Skin prick tests with dog dander in patients sensitized to house dust mite. (J Allergy Clin Immunol 1996;98:1028-34.)
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vineyard snail allergy possibly induced by sensitization to house dust mite dermatophagoides pteronyssinus
Allergy, 1995Co-Authors: F De Maatbleeker, Jaap H Akkerdaas, Rob C AalberseAbstract:: A female patient experienced a severe allergic reaction after consumption of vineyard snails. The patient proved to be sensitized to house-dust mite (HDM) and demonstrated a Positive Skin test and specific IgE to snail (Eobania vermiculata, Lofarma). The snail RAST was > 80% inhibited by HDM, whereas the mite RAST was < 10% inhibited by snail extract. This is possibly another example of food allergy related to primary sensitization by an aeroallergen.
H M Jansen - One of the best experts on this subject based on the ideXlab platform.
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false Positive Skin prick test responses to commercially available dog dander extracts caused by contamination with house dust mite dermatophagoides pteronyssinus allergens
The Journal of Allergy and Clinical Immunology, 1996Co-Authors: M J Van Der Veen, Melchior Mulder, A M Witteman, Rob C Aalberse, H M JansenAbstract:Abstract BACKGROUND: In an outpatient population, a high frequency of Positive Skin prick test responses to dog dander was found in the absence of detectable IgE to dog dander in the RAST. The majority of these patients were sensitized to house dust mites (Dermatophagoides pteronyssinus) and had no obvious dog-related allergic symptoms. These findings prompted us to investigate whether dog dander Skin test preparations are contaminated with house dust mite allergens in amounts sufficient to cause false-Positive Skin prick test responses in patients sensitized to house dust mites. METHODS: Antigen detection assays with monoclonal and polyclonal antibodies were used to determine concentrations of the major allergen Can f 1 from dog dander and the major allergens Der p 1 and Der p 2 from house dust mites in five commercially available dog dander Skin prick test preparations (A to E). RESULTS: Can f 1 concentrations varied for the different extracts (A: 170 μg/ml, B: 11.1 μg/ml, C: 13.3 μg/ml, D: 3.8 μg/ml, and E: 59.4 μg/ml). Der p 1 was detectable in all extracts (A: 33.4 ng/ml, B: 5.1 ng/ml, C: 29.6 ng/ml, D: 0.4 ng/ml, and E: 1.9 ng/ml), and Der p 2 was detectable in some of the commercially available dog dander Skin prick test preparations tested (A: 31.3 ng/ml, B: 3.0 ng/ml, and C: 7.5 ng/ml). The median house dust mite threshold in the Skin prick test was found to be 5.8 ng/ml of Der p 1 (range, 3.5 to 20.8 ng/ml) in nine patients tested. CONCLUSION: Contamination of commercially available dog dander Skin prick test preparations with the major allergens (Der p 1 and Der p 2) of the house dust mite (D. pteronyssinus) was demonstrated. These contaminations cause false-Positive responses to Skin prick tests with dog dander in patients sensitized to house dust mite. (J Allergy Clin Immunol 1996;98:1028-34.)
M J Van Der Veen - One of the best experts on this subject based on the ideXlab platform.
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false Positive Skin prick test responses to commercially available dog dander extracts caused by contamination with house dust mite dermatophagoides pteronyssinus allergens
The Journal of Allergy and Clinical Immunology, 1996Co-Authors: M J Van Der Veen, Melchior Mulder, A M Witteman, Rob C Aalberse, H M JansenAbstract:Abstract BACKGROUND: In an outpatient population, a high frequency of Positive Skin prick test responses to dog dander was found in the absence of detectable IgE to dog dander in the RAST. The majority of these patients were sensitized to house dust mites (Dermatophagoides pteronyssinus) and had no obvious dog-related allergic symptoms. These findings prompted us to investigate whether dog dander Skin test preparations are contaminated with house dust mite allergens in amounts sufficient to cause false-Positive Skin prick test responses in patients sensitized to house dust mites. METHODS: Antigen detection assays with monoclonal and polyclonal antibodies were used to determine concentrations of the major allergen Can f 1 from dog dander and the major allergens Der p 1 and Der p 2 from house dust mites in five commercially available dog dander Skin prick test preparations (A to E). RESULTS: Can f 1 concentrations varied for the different extracts (A: 170 μg/ml, B: 11.1 μg/ml, C: 13.3 μg/ml, D: 3.8 μg/ml, and E: 59.4 μg/ml). Der p 1 was detectable in all extracts (A: 33.4 ng/ml, B: 5.1 ng/ml, C: 29.6 ng/ml, D: 0.4 ng/ml, and E: 1.9 ng/ml), and Der p 2 was detectable in some of the commercially available dog dander Skin prick test preparations tested (A: 31.3 ng/ml, B: 3.0 ng/ml, and C: 7.5 ng/ml). The median house dust mite threshold in the Skin prick test was found to be 5.8 ng/ml of Der p 1 (range, 3.5 to 20.8 ng/ml) in nine patients tested. CONCLUSION: Contamination of commercially available dog dander Skin prick test preparations with the major allergens (Der p 1 and Der p 2) of the house dust mite (D. pteronyssinus) was demonstrated. These contaminations cause false-Positive responses to Skin prick tests with dog dander in patients sensitized to house dust mite. (J Allergy Clin Immunol 1996;98:1028-34.)
Carsten Bindslevjensen - One of the best experts on this subject based on the ideXlab platform.
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is a Positive intracutaneous test induced by penicillin mediated by histamine a cutaneous microdialysis study in penicillin allergic patients
Clinical and Translational Allergy, 2017Co-Authors: Line K. Tannert, Sidsel Falkencrone, Charlotte G. Mortz, Carsten Bindslevjensen, Per Stahl SkovAbstract:Diagnostic workup of penicillin allergy comprises Skin testing with penicillins, and patients are deemed allergic if Skin test is Positive. However, the literature suggests that Skin test-Positive patients may be challenge-negative, indicating that the Skin test may be falsely Positive. To investigate real-time histamine release from a Positive intracutaneous test induced by penicillin in patients with Positive and negative challenges to penicillin. Skin microdialysis was performed in 21 penicillin-allergic patients with Positive Skin test, 13 non-allergic volunteers serving as negative controls, and 7 grass pollen-allergic patients serving as Positive controls. Histamine was measured by microdialysis after Skin test with penicillin/grass/NaCl. Penicillin challenge was subsequently performed in 12 of the patients. Only 10/21 patients (47.6%) were Skin test Positive at microdialysis. During microdialysis 13 single intracutaneous tests were Positive and histamine was detected in 4/13 occurring in four challenge Positive patients. Thirteen/21 patients (61.9%) were deemed allergic to penicillin; eight had Positive Skin test. Two patients with Positive Skin test were challenge negative. In grass pollen allergic patients, 7/7 had a Positive intracutaneous test to grass and all released histamine in the wheals. All 13 negative controls had negative intracutaneous test to penicillin and no histamine release. Histamine was only detected in the minority of Positive intracutaneous tests with penicillin in penicillin-allergic patients. Other mediators may be involved.
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Positive Skin test or specific ige to penicillin does not reliably predict penicillin allergy
The Journal of Allergy and Clinical Immunology: In Practice, 2017Co-Authors: Line K. Tannert, Charlotte G. Mortz, Per Stahl Skov, Carsten BindslevjensenAbstract:Introduction According to guidelines, patients are diagnosed with penicillin allergy if Skin test (ST) result or specific IgE (s-IgE) to penicillin is Positive. However, the true sensitivity and specificity of these tests are presently not known. Objective To investigate the clinical relevance of a Positive ST result and Positive s-IgE and to study the reproducibility of ST and s-IgE. Methods A sample of convenience of 25 patients with Positive penicillin ST results, antipenicillin s-IgE results, or both was challenged with their culprit penicillin. Further 19 patients were not challenged, but deemed allergic on the basis of a recent anaphylactic reaction or delayed reactions to Skin testing. Another sample of convenience of 18 patients, 17 overlapping with the 25 challenged, with initial Skin testing and s-IgE (median, 25; range, 3-121), months earlier ( T −1 ), was repeat Skin tested and had s-IgE measured ( T 0 ), and then Skin tested and had s-IgE measured 4 weeks later ( T 1 ). Results Only 9 (36%) of 25 were challenge Positive. There was an increased probability of being penicillin allergic if both ST result and s-IgE were Positive at T 0 . Positive ST result or Positive s-IgE alone did not predict penicillin allergy. Among the 18 patients repeatedly tested, 46.2% (12 of 25) of Positive ST results at T −1 were reproducibly Positive at T 0 . For s-IgE, 54.2% (14 of 24) Positive measurements were still Positive at T 0 and 7 converted to Positive at T 1 . Conclusions The best predictor for a clinically significant (IgE-mediated) penicillin allergy is a combination of a Positive case history with simultaneous Positive ST result and s-IgE or a Positive challenge result.
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ga2len Skin test study ii clinical relevance of inhalant allergen sensitizations in europe
Allergy, 2009Co-Authors: G J Burbach, Carsten Bindslevjensen, L Heinzerling, G Edenharter, Claus Bachert, S Bonini, J Bousquet, L Bousquetrouanet, P J Bousquet, M BrescianiAbstract:BACKGROUND: Skin prick testing is the standard for diagnosing IgE-mediated allergies. A Positive Skin prick reaction, however, does not always correlate with clinical symptoms. A large database from a Global Asthma and Allergy European Network (GA(2)LEN) study with data on clinical relevance was used to determine the clinical relevance of sensitizations against the 18 most frequent inhalant allergens in Europe. The study population consisted of patients referred to one of the 17 allergy centres in 14 European countries (n = 3034, median age = 33 years). The aim of the study was to assess the clinical relevance of Positive Skin prick test reactions against inhalant allergens considering the predominating type of symptoms in a pan-European population of patients presenting with suspected allergic disease. METHODS: Clinical relevance of Skin prick tests was recorded with regard to patient history and optional additional tests. A putative correlation between sensitization and allergic disease was assessed using logistic regression analysis. RESULTS: While an overall rate of >or=60% clinically relevant sensitizations was observed in all countries, a differential distribution of clinically relevant sensitizations was demonstrated depending on type of allergen and country where the prick test was performed. Furthermore, a significant correlation between the presence of allergic disease and the number of sensitizations was demonstrated. CONCLUSION: This study strongly emphasizes the importance of evaluating the clinical relevance of Positive Skin prick tests and calls for further studies, which may, ultimately, help increase the Positive predictive value of allergy testing.
Zhang Wen - One of the best experts on this subject based on the ideXlab platform.
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approximate analytical and numerical solutions for radial non darcian flow to a well in a leaky aquifer with wellbore storage and Skin effect
International Journal for Numerical and Analytical Methods in Geomechanics, 2013Co-Authors: Zhang Wen, Quanrong WangAbstract:SUMMARY This study investigated non-Darcian flow to a well in a leaky aquifer considering wellbore storage and a finite-thickness Skin. The non-Darcian flow is described by the Izbash equation. We have used a linearization procedure associated with the Laplace transform to solve such a non-Darcian flow model. Besides, the Stehfest method has been used to invert the Laplace domain solutions for the drawdowns. We further analyzed the drawdowns inside the well for different cases. The results indicated that a smaller BD results in a smaller drawdown at late times and the leakage has little effect on the drawdown inside the well at early times, where BD is a dimensionless parameter reflecting the leakage. We have also found that the flow for the negative Skin case approaches the steady-state earlier than that for the Positive Skin. In addition, the drawdown inside the well with a Positive Skin is larger than that without Skin effect at late times, and a larger thickness of the Skin results in a greater drawdown inside the well at late times for the Positive Skin case. A reverse result has been found for the negative Skin case. Finally, we have developed a finite-difference solution for such a non-Darcian flow model and compared the numerical solution with the approximate analytical solution. It has been shown that the linearization procedure works very well for such a non-Darcian flow model at late times, and it underestimates the drawdowns at early times. Copyright © 2012 John Wiley & Sons, Ltd.
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constant head test in a leaky aquifer with a finite thickness Skin
Journal of Hydrology, 2011Co-Authors: Hongbin Zhan, Guanhua Huang, Zhang Wen, Menggui JinAbstract:Summary Constant-head test is a commonly used aquifer testing method in groundwater hydrology. A mathematical model for constant-head test in a leaky aquifer with a finite-thickness Skin was developed in this study. Three different aquifer–aquitard systems were considered and the Laplace-domain solutions were obtained and then inverted numerically with the Stehfest method to yield the time-domain solutions. The well discharges for different cases were computed and a sensitivity analysis of the well discharge on different parameters was performed. The results indicated that the dimensionless transmissivity of the aquitard had little effect on the well discharge at early times while a larger transmissivity of the aquitard leaded to a larger well discharge at late times. The well discharge for the Positive Skin was smaller than that without the Skin while the well discharge for the negative Skin was larger than that without the Skin, where Positive and negative Skins refer to the cases in which the permeability values of the Skin zones are less and greater than that of the formation zone, respectively. A thicker Skin resulted in a smaller well discharge for the Positive Skin case but leaded to a larger well discharge for the negative Skin case at late times. We also found that the drawdown for the Positive Skin case was less than that for the negative Skin case at the same time, and a Positive Skin might result in delayed response of the aquifer to pumping. The sensitivity analysis indicated that the well discharge was sensitive to the properties of the Skin zone, but not sensitive to the properties of the aquitards for the aquifer–aquitard system presented in this study.