Chemical synthesis of some lecithin analogues potential inhibitors of phospholipase A

The chemical synthesis of a number of lecithin analogues is described. These compounds were prepared to study inhibitory properties in the enzymatic hydrolysis of normal lecithins by porcine pancreatic phospholipase A. The structures of the synthesized products resemble very much those of the normal lecithins, but differ in most cases in that part of the molecule which is supposed to be important either for the binding with phospholipase A or for the catalytic reaction. The synthesized compounds include stereo- and structural isomers of the normal lecithins (= substrates for phospholipase A) and lecithins modified in the alkyl chain, the ester bond, the glycerol backbone, and the phosphate moiety

Chemical synthesis of some lecithin analogues potential inhibitors of phospholipase A

The chemical synthesis of a number of lecithin analogues is described. These compounds were prepared to study inhibitory properties in the enzymatic hydrolysis of normal lecithins by porcine pancreatic phospholipase A. The structures of the synthesized products resemble very much those of the normal lecithins, but differ in most cases in that part of the molecule which is supposed to be important either for the binding with phospholipase A or for the catalytic reaction. The synthesized compounds include stereo- and structural isomers of the normal lecithins (= substrates for phospholipase A) and lecithins modified in the alkyl chain, the ester bond, the glycerol backbone, and the phosphate moiety

Clinical relevance is associated with allergen-specific wheal size in skin prick testing

Background: Within a large prospective study, the Global Asthma and Allergy European Network (GA2LEN) has collected skin prick test (SPT) data throughout Europe to make recommendations for SPT in clinical settings. Objective: To improve clinical interpretation of SPT results for inhalant allergens by providing quantitative decision points. Methods: The GA2LEN SPT study with 3068 valid data sets was used to investigate the relationship between SPT results and patient-reported clinical relevance for each of the 18 inhalant allergens as well as SPT wheal size and physician-diagnosed allergy (rhinitis, asthma, atopic dermatitis, food allergy). The effects of age, gender, and geographical area on SPT results were assessed. For each allergen, the wheal size in mm with an 80% positive predictive value (PPV) for being clinically relevant was calculated. Results: Depending on the allergen, from 40% (blatella) to 87-89% (grass, mites) of the positive SPT reactions (wheal size ≥ 3 mm) were associated with patient-reported clinical symptoms when exposed to the respective allergen. The risk of allergic symptoms increased significantly with larger wheal sizes for 17 of the 18 allergens tested. Children with positive SPT reactions had a smaller risk of sensitizations being clinically relevant compared with adults. The 80% PPV varied from 3 to 10 mm depending on the allergen. Conclusion: These 'reading keys' for 18 inhalant allergens can help interpret SPT results with respect to their clinical significance. A SPT form with the standard allergens including mm decision points for each allergen is offered for clinical use. © 2013 The Authors. Clinical & Experimental Allergy published by John Wiley & Sons Ltd

GA2LEN skin test study I: GALEN harmonization of skin prick testing: Novel sensitization patterns for inhalant allergens in Europe

Background: Skin prick testing is the standard for diagnosing IgE-mediated allergies. However, different allergen extracts and different testing procedures have been applied by European allergy centres. Thus, it has been difficult to compare results from different centres or studies across Europe. It was, therefore, crucial to standardize and harmonize procedures in allergy diagnosis and treatment within Europe. Aims: The Global Asthma and Allergy European Network (GALEN), with partners and collaborating centres across Europe, was in a unique position to take on this task. The current study is the first approach to implement a standardized procedure for skin prick testing in allergies against inhalant allergens with a standardized pan-European allergen panel. Methods: The study population consisted of patients who were referred to one of the 17 participating centres in 14 European countries (n = 3034, median age = 33 years). Skin prick testing and evaluation was performed with the same 18 allergens in a standardized procedure across all centres. Results: The study clearly shows that many allergens previously regarded as untypical for some regions in Europe have been underestimated. This could partly be related to changes in mobility of patients, vegetation or climate in Europe. Conclusion: The results of this large pan-European study demonstrate for the first time sensitization patterns for different inhalant allergens in patients across Europe. The standardized skin prick test with the standardized allergen battery should be recommended for clinical use and research. Further EU-wide monitoring of sensitization patterns is urgently needed. © 2009 John Wiley & Sons A/S

GA2LEN skin test study II: Clinical relevance of inhalant allergen sensitizations in Europe

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 (GA2LEN) 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 ≥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. © 2009 John Wiley & Sons A/S