Suppression of Airway Allergic Reactions by a Photocatalytic Filter Using Mouse Model

Photocatalytic filters installed in air purifiers have been used to purify spaces by decomposing allergenic substances. However, we have not found any reports that evaluate the effectiveness of photocatalytic filters in suppressing allergic reactions in living organisms. In this study, we intratracheally instilled ovalbumin (OVA) into OVA-sensitized mice after the OVA was photocatalyzed by a titanium dioxide (TiO2) filter, and verified the experimental model for evaluating the allergy-suppressing effect of photocatalysts. Mice were sensitized to OVA (10 µg/mouse) four times, and were intratracheally instilled with OVA (10 µg/mouse) after photocatalysis three times. Non-sensitized animals were instilled with normal saline following the same exposure schedule. The mice were dissected 24 h after final exposure. The OVA after photocatalysis significantly decreased the number of eosinophils in bronchoalveolar lavage fluid, and the concentration of OVA-specific IgE and IgG1 in serum, which were elevated in untreated OVA. Moreover, our experimental model showed the suppression of allergic reactions in mice, along with the decomposition of OVA after photocatalysis using the photocatalytic filter. Taken together, our experimental model for evaluating allergic reactions in the respiratory tract suggested that the allergy-suppressing effect of the photocatalytic filter can be evaluated.

Amoxicillin Haptenation of α-Enolase is Modulated by Active Site Occupancy and Acetylation

Allergic reactions to antibiotics are a major concern in the clinic. ß-lactam antibiotics are the class most frequently reported to cause hypersensitivity reactions. One of the mechanisms involved in this outcome is the modification of proteins by covalent binding of the drug (haptenation). Hence, interest in identifying the corresponding serum and cellular protein targets arises. Importantly, haptenation susceptibility and extent can be modulated by the context, including factors affecting protein conformation or the occurrence of other posttranslational modifications. We previously identified the glycolytic enzyme α-enolase as a target for haptenation by amoxicillin, both in cells and in the extracellular milieu. Here, we performed an in vitro study to analyze amoxicillin haptenation of α-enolase using gel-based and activity assays. Moreover, the possible interplay or interference between amoxicillin haptenation and acetylation of α-enolase was studied in 1D- and 2D-gels that showed decreased haptenation and displacement of the haptenation signal to lower pI spots after chemical acetylation of the protein, respectively. In addition, the peptide containing lysine 239 was identified by mass spectrometry as the amoxicillin target sequence on α-enolase, thus suggesting a selective haptenation under our conditions. The putative amoxicillin binding site and the surrounding interactions were investigated using the α-enolase crystal structure and molecular docking. Altogether, the results obtained provide the basis for the design of novel diagnostic tools or approaches in the study of amoxicillin-induced allergic reactions.

A prospective study of costs associated with the evaluation of allergic reactions to radiological contrast media

Background: The prevalence of hypersensitivity reactions to radiological contrast media (RCM) is increasing due to the greater performance of diagnostic and therapeutic tests that require RCMs. Objective: We carried out a year-long real-life observational study to prospectively evaluate the patients referred to the Allergy Service from Primary Care, Emergency Room, and other Services with suspected moderate to severe RCM hypersensitivity. Methods: To study the costs of RCM hypersensitivity evaluation, we systematically recorded direct and indirect costs. Results: Sixty-nine patients with previous reactions to RCM were evaluated in the Allergy Service from June 1st, 2017, to May 31st, 2018. Total direct health care costs were € 10715.84, with a mean cost per patient of € 155.30 ± 77.08. Specifically, direct non-health costs reached € 1605.42 (mean € 23.27 ± 41.14), and indirect costs were € 6490.85 (mean € 94.07 ± 110.61). In summary, the total cost was € 18812.11, which means a mean cost of € 272.64 ± 164.77. Conclusions: Our study reflects that the costs of an elective evaluation of hypersensitivity to RCM are low. This fact reaffirms that correct and safe management of these patients could be cost-effective, so our efforts should be directed to implement the necessary logistics.

Vaccinating with a COVID-19 Vaccine: Experience of the Tertiary Allergology Center

Background: Allergic reactions after messenger RNA (mRNA)-based COVID-19 vaccines have been reported but detailed descriptions and further actions are not well characterized. Objective: To describe the symptoms of possible allergic reactions after the mRNA COVID-19 vaccine and outcomes of further vaccination. Methods: We descriptively analyzed data of adult (≥18 years of age) patients, who were sent for vaccination to our outpatient center for the Diagnostics and Treatment of Allergic and Immune diseases. All patients were vaccinated with the Pfizer–BioNTech Comirnaty® vaccine.Results: From January 2021 to July 2021 twenty-two patients were vaccinated in our center. Six patients experienced a reaction after the first Comirnaty® dose in different vaccination centers. The majority of them complained of various types of rashes after the first dose, one case was consistent with anaphylaxis. The latter patient was tested with the skin prick using Pfizer–BioNTech Comirnaty® vaccine and the test was negative. Other sixteen patients were vaccinated in our center from the first dose because of past allergic reactions to other medication or due to concomitant mast cell disorder. All patients were vaccinated without any immediate adverse reactions.Conclusions: None of our patients experienced repeated cutaneous reactions after the second dose. Patients with previous anaphylaxis or mastocytosis also were safely vaccinated.

Association between the type of allergen and T-helper 2 mediated inflammation in allergic reactions: a systematic review and a meta-analysis

Objectives: To determine whether the levels of T-helper (TH) 2 cytokines (interleukin (IL)-4 and IL-5) in allergic reactions are allergen dependent and evaluate the impact of various treatment strategies on the levels of these cytokines.Methods: The PubMed search engine was used from inception until January 2021. The random-effects residual maximum likelihood model was performed, and effect sizes were estimated using the Hedge’s g statistic. All data analysis was performed using STATA 16.0 (StataCorp LP, TX, USA). Results: Fourteen studies reporting on 794 participants were included in this study. House dust mite was associated with eliciting a stronger immune response mediated by both IL-4 and IL-5 when compared to pollen. Whereas a mixture of house dust mite and pollen was associated with IL-4-weighted inflammation. Comparisons of IL-4 and IL-5 levels amongst the allergens showed significant differences. The treatment with anti-corticosteroids or allergen-specific immunotherapy was effective in normalising the TH2 responses and alleviating allergy symptoms.Conclusion: TH2-mediated inflammation in allergic reactions is allergen-dependent. Therefore, the type of allergen should be considered when using cytokine-targeting biologics in allergic reactions.

The influence of mother's diseases and complications of pregnancy on the development of allergic reactions in neonates and infants

The article reviews the materials dealing with the role of mothers diseases, complications of pregnancy, and unfavorable environmental factors in formation of immunological reactions in neonates. The author emphasizes the role of disturbances of afterbirth state in case of gestosis, infections, mothers smoking.Peculiarities of immune mechanisms of neonates compared with those of elder children determine their reactivity and early development of allergic diseases.