Synthesis of skeletally diverse ß-lactam haptens for the in vitro diagnosis of IgE-mediated drug allergy.

We present the first synthesis of ß-lactam-derived haptens, leveraging the principles of diversity-oriented synthesis to discover compounds for drug allergy in vitro testing. We designed, synthesised, and performed in vitro immunological evaluation on 18 structurally diverse haptens derived from ß-lactam antibiotics. The antigens obtained with the synthesised haptens allow for the detection of specific anti-ß-lactam immunoglobulins G and E. Excellent diagnostic sensitivity (83%) and specificity (100%) were achieved when the panel of antigens was tested against a cohort of 31 human serum samples using a multiplexed compact disc-based in vitro testing tool. We posit that adopting this strategy could aid ß-lactam delabeling initiatives.

Multiplexed analytical approaches to beta-lactam allergy in vitro testing standardization.

The suspicion of beta-lactam allergy directly contributes to the prescription of antibiotics that diverge from the guidelines, increasing antimicrobial resistance, one of the biggest threats to global health. In vitro quantification of specific IgE is very useful for monitoring allergy, as it confirms or rules out immediate beta-lactam drug allergy and helps find safe alternative antibiotic stewardship. However, reliable in vitro quantification of specific IgE to beta-lactam antibiotics by immunoassay is challenging because of the difficulty of having selective immunoreagents, mainly beta-lactam antigens, and its low concentration levels in serum. Thus, reliable and sensitive in vitro tests for multiplex detection of allergy to different beta-lactam antibiotics is currently essential for clinical diagnosis. Nevertheless, the lack of standardization of quantitative in vitro methods makes the comparison and interpretation of the results difficult. Here, as proof of concept, we report an improved multiplex microimmunoassay for beta-lactam allergy in vitro testing standardization. The results revealed that homologous calibration allows reliable quantification of specific IgE in human serum at very low concentrations (144 ng L-1). Moreover, the reproducibility of the results increases 2-fold using an internal standard, achieving accurate quantitative information: 93% and 106% recovery for penicillin and amoxicillin, respectively. We simultaneously evaluated the reliability of the improved multiplexed in vitro method in a cohort of 40 human serum samples and achieved excellent agreement (0.99) with a currently used in vitro test.

Tolerability and positive efficacy results after subcutaneous immunotherapy with Parietaria judaica depot extract.

AIM: To evaluate tolerability and efficacy of Parietaria judaica subcutaneous immunotherapy on patients with allergic rhinoconjunctivitis. PATIENTS & METHODS: 51 patients were assigned to build-up scheme (six increasing doses) of P. judaica depot native extract, plus three maintenance monthly administrations. RESULTS: Out of 470 administered doses, only 3.8% elicited systemic reactions (1.5% nonspecific and 2.3% grade I). Concerning the exploratory efficacy parameters: cutaneous reactivity at the final visit versus baseline was significantly decreased; specific titers of IgG and IgG4 increased significantly and patients showed a significant decrease in the rhinitis symptoms score. CONCLUSION: P. judaica subcutaneous immunotherapy (Allergovac® depot ROXALL Medicina España S.A., Zamudio, Spain) with an abbreviated up-dosing scheme showed an adequate safety and tolerability profile and induced preliminary efficacy changes.

Negative clinical results from a randomised, double-blind, placebo-controlled trial evaluating the efficacy of two doses of immunologically enhanced, grass subcutaneous immunotherapy despite dose-dependent immunological response.

OBJECTIVE: Specific immunotherapy is the only treatment for the underlying allergic disease in patients with respiratory allergies. The primary objective of this trial was to evaluate the efficacy and safety of two maintenance doses of immunologically enhanced, standardised quality (SQ+) grass subcutaneous immunotherapy (SCIT) [4,000 SQ+ and 15,000 SQ+; AVANZ(®) Phleum pratense (ALK)] compared with placebo. METHODS: This was a randomised, double-blind, placebo-controlled, phase II/III trial. The primary evaluation was based on the combined rhinoconjunctivitis score during the entire grass pollen season. Adult subjects with grass pollen-induced allergic rhinoconjunctivitis interfering with usual activities or sleep despite symptomatic medication use, were enrolled. RESULTS: Four hundred and fifty subjects were randomised to receive either 4,000 SQ+ (n = 150), 15,000 SQ+ (n = 152) or placebo (n = 148). The average grass pollen exposure was 27 grains/m(3)/day. No statistically significant differences between the active groups and the placebo group were found for clinical endpoints (p > 0.05). Highly statistically significant (p < 0.001) increases in IgG4 and IgE-blocking factor were found for both active groups versus placebo. The most frequently reported adverse events were mild-to-moderate local injection-site reactions; events were generally more frequent with 15,000 SQ+ than with 4,000 SQ+ and placebo. The most common adverse events leading to premature discontinuation from the trial were anaphylactic reactions (one subject from the placebo group and five subjects from the 15,000 SQ+ group). CONCLUSIONS: The inconclusive results were most probably influenced by a very low grass pollen season. Other factors such as the extent of the pre-seasonal treatment could potentially have contributed. The tolerability profile was acceptable for further development.

Development of a disease-specific quality of life questionnaire for adult patients with hereditary angioedema due to C1 inhibitor deficiency (HAE-QoL): Spanish multi-centre research project.

BACKGROUND: There is a need for a disease-specific instrument for assessing health-related quality of life in adults with hereditary angioedema due to C1 inhibitor deficiency, a rare, disabling and life-threatening disease. In this paper we report the protocol for the development and validation of a specific questionnaire, with details on the results of the process of item generation, domain selection, and the expert and patient rating phase. METHODS/DESIGN: Semi-structured interviews were completed by 45 patients with hereditary angioedema and 8 experts from 8 regions in Spain. A qualitative content analysis of the responses was carried out. Issues raised by respondents were grouped into categories. Content analysis identified 240 different responses, which were grouped into 10 conceptual domains. Sixty- four items were generated. A total of 8 experts and 16 patients assessed the items for clarity, relevance to the disease, and correct dimension assignment. The preliminary version of the specific health-related quality of life questionnaire for hereditary angioedema (HAE-QoL v 1.1) contained 44 items grouped into 9 domains. DISCUSSION: To the best of our knowledge, this is the first multi-centre research project that aims to develop a specific health-related quality of life questionnaire for adult patients with hereditary angioedema due to C1 inhibitor deficiency. A preliminary version of the specific HAE-QoL questionnaire was obtained. The qualitative analysis of interviews together with the expert and patient rating phase helped to ensure content validity. A pilot study will be performed to assess the psychometric properties of the questionnaire and to decide on the final version.