IgE-Mediated Cannabis Allergy and Cross-Reactivity Syndromes: A Roadmap for Correct Diagnosis and Management.

PURPOSE OF THE REVIEW: With increased access and decriminalization of cannabis use, cases of IgE-dependent cannabis allergy (CA) and cross-reactivity syndromes have been increasingly reported. However, the exact prevalence of cannabis allergy and associated cross-reactive food syndromes (CAFS) remains unknown and is likely to be underestimated due to a lack of awareness and insufficient knowledge of the subject among health care professionals. Therefore, this practical roadmap aims to familiarize the reader with the early recognition and correct management of IgE-dependent cannabis-related allergies. In order to understand the mechanisms underlying these cross-reactivity syndromes and to enable personalized diagnosis and management, special attention is given to the molecular diagnosis of cannabis-related allergies. RECENT FINDINGS: The predominant signs and symptoms of CA are rhinoconjunctivitis and contact urticaria/angioedema. However, CA can also present as a life-threatening condition. In addition, many patients with CA also have distinct cross-reactivity syndromes, mainly involving fruits, vegetables, nuts and cereals. At present, five allergenic components of Cannabis sativa (Can s); Can s 2 (profilin), Can s 3 (a non-specific lipid protein), Can s 4 (oxygen-evolving enhancer protein 2 oxygen), Can s 5 (the Bet v 1 homologue) and Can s 7 (thaumatin-like protein) have been characterized and indexed in the WHO International Union of Immunological Sciences (IUIS) allergen database. However, neither of them is currently readily available for diagnosis, which generally starts by testing crude extracts of native allergens. The road to a clear understanding of CA and the associated cross-reactive food syndromes (CAFS) is still long and winding, but well worth further exploration.

Parallelized Immunomagnetic Isolation of Basophils Directly from Whole Blood.

Basophils are the rarest circulating white blood cells (WBCs), but they play important roles in allergic disorders and other diseases. To enhance diagnostic capabilities, it would be desirable to isolate and analyze basophils efficiently from small blood samples. In 100 µL of whole blood, there are typically ~103 basophils, outnumbered by ~105 WBCs and ~108 red blood cells (RBCs). Basophils' low abundance has therefore presented a significant challenge in their isolation from whole blood. Conventional in-bulk basophil isolation methods require lengthy processing steps and cannot work with small volumes of blood. Here we report a parallelized integrated basophil isolation device (pi-BID) for the negative immunomagnetic selection of basophils directly from 4 samples of 100 µL of whole blood, in parallel, within 14 minutes including sample preparation time. The pi-BID interfaces directly with standard sample tubes, and uses a single pressure source to drive the flow in parallel microfluidic channels. Compared with conventional in-bulk basophil isolation, the pi-BID is >3× faster, and has higher purity (~93%) and similar recovery (~67%). Compared with other microfluidic devices for the immunomagnetic isolation of WBC sub-types, our pi-BID achieves 10× higher enrichment of target cells from whole blood, with no prior removal of RBCs necessary.

Blood Stored In EDTA Tubes Provides Accurate Peanut Basophil Activation Test Results For 48 hours.

BACKGROUND: The peanut basophil activation test (BAT) has demonstrated excellent diagnostic accuracy with heparinized blood, but its clinical utility is limited by the short stability of samples stored in this anticoagulant. OBJECTIVE: Using EDTA anticoagulated blood, these investigations determined if Peanut BAT sample stability can be extended to 2 days, the minimum stability requirement for diagnostic tests currently offered through American reference laboratories. METHODS: Peanut non-allergic control (NAC), peanut IgE sensitized (PS), and peanut allergic (PA) children aged 6 months through 17 years were recruited from members of Kaiser Permanente Southern California. EDTA anti-coagulated blood samples were collected from participants, shipped to a centralized laboratory, and stored at 4oC for peanut BAT testing 1 and 2 days later. RESULTS: Peanut BAT results for 23 unblinded participants were used to establish sample rejection and interpretation criteria that were subsequently validated in a prospective double-blind study involving 112 additional children (39-NAC, 36-PS, 37-PA). Of 105 blinded blood samples tested on each study day, 88 (84%) day-1 and 90 (86%) day-2 peanut BAT results were considered interpretable, with diagnostic accuracies of 95.5% and 94.4%, respectively. Moreover, all interpretable PA results were considered positive (100% sensitivity). CONCLUSION: Using EDTA anti-coagulated blood samples collected remotely, 1 and 2 days before testing, study results highlight the favorable diagnostic performance characteristics of the peanut BAT and provide further evidence that the test could be readily operationalized for clinical use by interested commercial reference laboratories.

Basophil Activation Test Predicts Cetuximab Anaphylaxis Severity in Alpha-Gal IgE-Positive Patients.

Upon first exposure to cetuximab, hypersensitivity reactions can occur. We aimed to assess the utility of the basophil activation test (BAT) to alpha-gal and cetuximab for predicting severe reactions. We prospectively recruited 38 patients and evaluated sIgE to alpha-gal in all patients before the first application of cetuximab. In all alpha-gal-sensitized patients, we evaluated skin tests to meat extracts, gelatine, and cetuximab and performed BAT with alpha-gal and cetuximab. In 24% (9/38) of patients, sIgE to alpha-gal was >0.10 kUA/L, and 8/9 reacted to the cetuximab. Basophil activation tests with alpha-gal were positive in all sensitized patients and were higher in those with severe reactions (18.3% in grade 4 [n = 4] vs. 1.8% in grade 2 [n = 3] or no reaction [n = 1] at 3.3 ng/mL of alpha-gal; p = 0.03). All patients with severe grade 4 reactions had a positive CD63 BAT response to cetuximab compared to patients with moderate or no reaction, who all had negative BAT (57.7% vs. 0.9% at 500 µg/mL, 63.2% vs. 4.1% at 100 µg/mL, 58.2% vs. 2.7% at 10 µg/mL, and 32.1% vs. 3.3% at 1 µg/mL of cetuximab, respectively; p ≤ 0.001). In summary, before initiating cetuximab treatment, sIgE to alpha-gal should be assessed in all patients. To predict the severity of the reaction and to assess the risk of cetuximab-induced anaphylaxis, we should perform BATs with alpha-gal or more discriminative BATs with cetuximab.

Allergenic potency of various foods of mammalian origin in patients with α-Gal syndrome.

BACKGROUND: The α-Gal syndrome (AGS) is an emerging allergy to mammalian food caused by IgE-mediated reactions to the carbohydrate galactose-α-1,3-galactose (α-Gal). Mammalian food sources contain α-Gal, but the amount differs. The objective of this study was to investigate the allergenic potency of various foods of mammalian origin among AGS patients. METHODS: Twenty-six AGS patients were included. Food extracts from innards, lean meats, processed meat products, milk, and whey were analyzed. Immunoblot, ELISA, immunofluorescence, and basophil activation test were used to determine the α-Gal content, characterize IgE binding, and assess foods' allergenicity. RESULTS: The determined amount of α-Gal, IgE reactivity to food extracts, and food extract potencies to activate patients' basophils correlated well with each other. Pork and beef kidney showed the highest allergenicity. Beef liver and bacon showed allergenicity comparable to that of lean meats. Game meat seemed to have a higher allergenic potency than meats from farm-raised animals. The processed meat products liver pâté and black pudding, despite lower α-Gal content, demonstrated moderate allergenicity. Milk showed the lowest allergenicity. IgE reactivity to food extracts was highly similar for all patients and strongly dominated by the α-Gal epitope. CONCLUSIONS: The allergenic potency of mammalian meat depends on the origin of the meat, the different cuts, and type of processing, with innards posing the greatest risk to AGS patients. Even processed mammalian meat constitutes a risk. Dairy products show the lowest risk. This study highlights the importance of analyzing even more foods to improve the management of AGS.

Identification of Alpha-Gal glycolipids in saliva of Lone-Star Tick (Amblyomma americanum).

Alpha-Gal Syndrome (AGS) is a delayed allergic reaction triggered by IgE antibodies targeting galactose-α-1,3-galactose (α-gal), prevalent in red meat. Its global significance has increased, with over 450,000 estimated cases in the United States alone. AGS is linked to tick bites, causing sensitization and elevated α-gal specific IgE levels. However, the precise mechanisms and tick intrinsic factors contributing to AGS development post-tick bites remain unclear. This study aims to characterize the alpha-gal conjugated lipid antigens in Amblyomma americanum (Am. americanum) salivary glands and saliva. Nanospray ionization mass spectrometry (NSI-MS) analysis revealed the identification of α-gal bound lipid antigens in Am. americanum saliva. Additionally, the activation of basophils by extracted alpha-gal bound lipids and proteins provides evidence of their antigenic capabilities.

The role of basophil activation test in venom immunotherapy: comparative evaluation with specific IgE and skin prick tests, innovative approaches.

Summary: Background. In diagnosing insect venom allergy and making immunotherapy decisions, clinical history, skin tests, and specific serum IgE levels are commonly utilized. This study aims to emphasize the clinical significance of using the basophil activation test in accurately identifying sensitivities in individuals with insect venom allergy and to compare its effectiveness with other testing methods. Methods. This study included a total of 43 patients, who experienced at least one systemic allergic reaction following insect stings and were deemed suitable for immunotherapy.Basophil activation test, specific serum IgE levels, and skin prick test results utilized in making immunotherapy treatment decisions were recorded. Results. Our study determined that the overall clinical sensitivities of the basophil activation test (BAT), specific serum IgE (spIgE), and skin prick test (SPT) for apis mellifera were 95.5%, 95.7%, and 48.4% respectively, while for vespula vulgaris, they were 83.3%, 100%, and 33.3%. Based on these results, the prediction of systemic reactions to bee stings is ordered as spIgE > BAT > SPT. Additionally, early-stage skin prick tests showed a sensitivity of 67% and specificity of 50% at a cut-off value of 1.5 mm, and 33% sensitivity and 83% specificity at 2.5 mm. Conclusions. This study demonstrates that the basophil activation test (BAT) can provide a high positive predictive value in immunotherapy treatment decisions and offer significant insights in clinical practices.

Functional characterization of complete and immunodominant epitopes of a novel pollen allergen from Parthenium hysterophorus.

Summary: .Background. Parthenium hysterophorus pollen induces chronic clinical conditions such as allergic rhinitis and bronchial asthma. Among the plethora of proteins in the pollens, only few were reported to induce allergy. Currently sensitization to P. hysterophorus pollen allergen is diagnosed by skin prick test (SPT) using the entire pollen extract instead of using the specific allergen. Methods. In P. hysterophorus sensitized patients, SPT was done using the crude pollen extract, 40 kDa allergenic pollen protein and two commercially synthesized allergen epitopes (17 and 24) of P. hysterophorus. Dot-blot of allergen epitopes was done using P. hysterophorus sensitized sera. Crude pollen extract (1, 1.25, 2.5, 5 and 10 µg/mL), 40 kDa allergenic protein (3 µg/mL), and allergen epitopes (3µg/mL) were used to perform Basophil Activation Test (BAT). Results. Crude pollen extract at 2.5, 5, 10 µg/mL and 40 kDa allergenic protein at 3µg/mL concentrations induced wheal and flare reaction by around 15 minutes, whereas commercially synthesized allergen epitopes at 3µg/mL induced wheal and flare reactions in less than 10 minutes. Allergen epitopes (3 µg/mL) revealed strong reactivity with sensitized patient's IgE in dot-blot analysis. Basophil activation Test using crude pollen extract (2.5, 5, 10 µg/mL), 40 kDa allergenic protein (3 µg/mL), and allergenic epitopes (3µg/mL) indicated significant basophil activation (as measured by CD63 expression) in sensitized patients. Conclusions. The 40 kDa allergenic protein and its allergenic epitopes (17 and 24) induced phenotypic and cellular immune responses in P. hysterophorus sensitized individuals. The tested allergenic epitopes (17 and 24) induced faster wheal and flare reactions in comparison with the crude extract and the 40 kDa allergenic protein. The novel 40kDa allergenic protein and its allergen epitopes identified here may be useful for the development of component-resolved diagnosis (CRD) while also serving as a potential therapeutic lead for desensitization treatment for P. hysterophorus pollen induced allergy.

Causal relationship between blood traits and severe influenza A(H1N1)pdm09 infection in East Asian: A Mendelian randomization study.

Although a range of blood traits have been reported to be associated with influenza A(H1N1)pdm09 (H1N1pdm09) disease severity, their underlying causal relationships and biological mechanisms have remained unclear. This study aimed to investigate the causal relationship between blood traits and H1N1pdm09 using a two-sample Mendelian randomization analysis. Based on the data from our in-house genome-wide association study (GWAS) on H1N1pdm09 disease severity (Ncase [severe] = 70, Ncontrol [mild] = 95) and GWAS summaries of 44 blood traits from Biobank Japan (N = 12 303-143 658), we identified the potential causal effect of blood traits on severe H1N1pdm09. The inverse variance weighted method analysis revealed significant causal effects of lower aspartate aminotransferase (AST, ß = -3.212, p = 0.019), low-density-lipoprotein cholesterol (LDL-C, ß = -1.372, p = 0.045), and basophil counts (Baso, ß = -1.638, p = 0.047) on severe H1N1pdm09 disease. Additionally, polygenic risk score analysis further confirmed genetic overlap between these blood traits and severe H1N1pdm09 disease. This study provided evidence linking the lower level of AST, LDL-C, and lower count of Baso with severe H1N1pdm09 disease, potentially identifying new therapeutic targets for patients with severe influenza.

The predictive value of hematological inflammatory markers for severe oral mucositis in patients with nasopharyngeal carcinoma during intensity-modulated radiation therapy: A retrospective cohort study.

BACKGROUND: This study aims to investigate the predictive value of the circulating blood cell count, including neutro-philto-lymphocyte ratio (NLR), platelet-to-lymphocyte (PLR), and thesystemic inflammation index (SII) for the development of severe oral mucositis (SOM) induced by radiation in patients undergoing radiotherapy for nasopharyngeal carcinoma (NPC). METHODS: In this retrospective study, 142 NPC patients were screened, and based on mucositis toxicity grade, they were categorized into two groups: SOM and nonSOM. Peripheral blood cell counts were conducted prior to Intensity-Modulated Radiation Therapy (IMRT). Associations between blood cell count, NLR, PLR, SII, and SOM occurrence were examined. RESULTS: Revealed elevated NLR and SII levels, along with reduced lymphocyte (LYM), eosinophil (EOS), and basophil (BAS) in patients with SOM. LYM, EOS, BAS, NLR, and SII were effective predictors of the severity of radiation-induced oral mucositis (RIOM) in NPC patients. CONCLUSIONS: The occurrence of SOM was strongly linked to the hematological status at the start of Radiation Therapy (RT). Integrating BAS count and NLR into comprehensive risk prediction models could prove valuable for predicting SOM in NPC patients.

Non-Specific Lipid Transfer Protein Amb a 6 Is a Source-Specific Important Allergenic Molecule in Ragweed Pollen.

Pollen from common ragweed is an important allergen source worldwide and especially in western and southern Romania. More than 100 million patients suffer from symptoms of respiratory allergy (e.g., rhinitis, asthma) to ragweed pollen. Among the eleven characterized allergens, Amb a 6 is a non-specific lipid transfer protein (nsLTP). nsLTPs are structurally stable proteins in pollen and food from different unrelated plants capable of inducing severe reactions. The goal of this study was to produce Amb a 6 as a recombinant and structurally folded protein (rAmb a 6) and to characterize its physicochemical and immunological features. rAmb a 6 was expressed in Spodoptera frugiperda Sf9 cells as a secreted protein and characterized by mass spectrometry and circular dichroism (CD) spectroscopy regarding molecular mass and fold, respectively. The IgE-binding frequency towards the purified protein was evaluated using sera from 150 clinically well-characterized ragweed-allergic patients. The allergenic activities of rAmb a 6 and the nsLTP from the weed Parietaria judaica (Par j 2) were evaluated in basophil activation assays. rAmb a 6-specific IgE reactivity was associated with clinical features. Pure rAmb a 6 was obtained by insect cell expression. Its deduced molecular weight corresponded to that determined by mass spectrometry (i.e., 10,963 Da). rAmb a 6 formed oligomers as determined by SDS-PAGE under non-reducing conditions. According to multiple sequence comparisons, Amb a 6 was a distinct nsLTP with less than 40% sequence identity to currently known plant nsLTP allergens, except for nsLTP from Helianthus (i.e., 52%). rAmb a 6 is an important ragweed allergen recognized by 30% of ragweed pollen allergic patients. For certain patients, rAmb a 6-specific IgE levels were higher than those specific for the major ragweed allergen Amb a 1 and analysis also showed a higher allergenic activity in the basophil activation test. rAmb a 6-positive patients suffered mainly from respiratory symptoms. The assumption that Amb a 6 is a source-specific ragweed allergen is supported by the finding that none of the patients showing rAmb a 6-induced basophil activation reacted with Par j 2 and only one rAmb a 6-sensitized patient had a history of plant food allergy. Immunization of rabbits with rAmb a 6 induced IgG antibodies which strongly inhibited IgE binding to rAmb a 6. Our results demonstrate that Amb a 6 is an important source-specific ragweed pollen allergen that should be considered for diagnosis and allergen-specific immunotherapy of ragweed pollen allergy.

Basophil differentiation, heterogeneity, and functional implications.

Basophils, rare granulocytes, have long been acknowledged for their roles in type 2 immune responses. However, the mechanisms by which basophils adapt their functions to diverse mammalian microenvironments remain unclear. Recent advancements in specific research tools and single-cell-based technologies have greatly enhanced our understanding of basophils. Several studies have shown that basophils play a role in maintaining homeostasis but can also contribute to pathology in various tissues and organs, including skin, lung, and others. Here, we provide an overview of recent basophil research, including cell development, characteristics, and functions. Based on an increasing understanding of basophil biology, we suggest that the precise targeting of basophil features might be beneficial in alleviating certain pathologies such as asthma, atopic dermatitis (AD), and others.

Basophil allergen threshold sensitivity to casein (casein-specific CD-sens) predicts allergic reactions at a milk challenge in most but not all patients.

BACKGROUND: The basophil activation test is an emerging clinical tool in the diagnosis of cow's milk allergy (CMA). The aim was to assess the association between the basophil allergen threshold sensitivity to the major milk protein casein (casein-specific CD-sens), the levels of milk- and casein-specific Immunoglobulin E antibodies (IgE-ab), and the severity of allergic reactions at milk challenges. METHODS: We enrolled 34 patients aged 5-15 (median 9) years who underwent a double-blind placebo-controlled milk-challenge (DBPCMC) as screening before inclusion in an oral immunotherapy study for CMA. The severity of the allergic reaction at the DBPCMC was graded using Sampson's severity score. Venous blood was drawn before the DBPCMC. Milk- and casein-specific IgE-ab were analyzed. Following in vitro stimulation of basophils with casein, casein-specific CD-sens, was determined. RESULTS: Thirty-three patients completed the DBPCMC. There were strong correlations between casein-specific CD-sens and IgE-ab to milk (rs = 0.682, p < .001), and between casein-specific CD-sens and IgE-ab to casein (rs = 0.823, p < .001). There was a correlation between the severity of the allergic reaction and casein-specific CD-sens level (rs = 0.395, p = .041) and an inverse correlation between casein-specific CD-sens level and the cumulative dose of milk protein to which the patient reacted at the DBPCMC (rs = -0.418, p = .027). Among the 30 patients with an allergic reaction at the DBPCMC, 67% had positive casein-specific CD-sens, 23% had negative casein-specific CD-sens, and 10% were declared non-responders. CONCLUSION: Two thirds of those reacting at the DBPMC had positive casein-specific CD-sens, but reactions also occurred despite negative casein-specific CD-sens. The association between casein-specific CD-sens and the severity of the allergic reaction and cumulative dose of milk protein, respectively, was moderate.

Evaluation of peripheral inflammatory parameters of cases with suicide attempts.

PURPOSE: The purpose of the present study was to examine the inflammation markers of patients who have attempted suicide by comparing them with those of healthy controls. The leukocyte cell levels, Neutrophil/Lymphocyte Ratios (NLR), Basophil/Lymphocyte Ratios (BLR), Platelet/Lymphocyte Ratios (PLR), Monocyte/Lymphocyte Ratios (MLR), Systemic Inflammation Index (SII), Neutrophil/Albumin Ratios (NAR) values were compared with those of healthy controls. METHOD: A total of 376 people were included in the study (276 patients who attempted suicide, and 100 healthy people (the control group)). The demographic data and laboratory parameters of the participants were analyzed from the hospital automation system. RESULTS: The participants' female/male ratio was 158/118 (42.8%/57.1%) in the group of patients who attempted suicide and 41/59 (41/59%) in the control group. When the distribution of laboratory parameters was evaluated, although the NLR, BLR, NAR, SII, and MLR values, which are indicators of peripheral inflammation, were high in patients who attempted suicide (p = 0.049 for MLR, p = 0.000 for other values), the PLR (p = 0.586) value did not differ significantly between the groups. Patients who had attempted more than one suicide had elevated BLR (p = 0.007), SII (p = 0.003), and NAR (p = 0.003) values. DISCUSSION: Based on the results obtained, it was considered that paying attention to inflammation parameters in patient follow-ups, and monitoring of SII, NLR, BLR, and NAR values of patients who had attempted suicide once would be beneficial in preventing future suicide attempts. These results strengthen the idea that inflammatory processes play roles in the pathophysiology of suicidal behavior. However, further studies are needed to elucidate the complex pathophysiological mechanisms of immune pathways underlying suicidal behavior.

Single-cell proteomics and transcriptomics capture eosinophil development and identify the role of IL-5 in their lineage transit amplification.

The activities, ontogeny, and mechanisms of lineage expansion of eosinophils are less well resolved than those of other immune cells, despite the use of biological therapies targeting the eosinophilia-promoting cytokine interleukin (IL)-5 or its receptor, IL-5Rα. We combined single-cell proteomics and transcriptomics and generated transgenic IL-5Rα reporter mice to revisit eosinophilopoiesis. We reconciled human and murine eosinophilopoiesis and provided extensive cell-surface immunophenotyping and transcriptomes at different stages along the continuum of eosinophil maturation. We used these resources to show that IL-5 promoted eosinophil-lineage expansion via transit amplification, while its deletion or neutralization did not compromise eosinophil maturation. Informed from our resources, we also showed that interferon response factor-8, considered an essential promoter of myelopoiesis, was not intrinsically required for eosinophilopoiesis. This work hence provides resources, methods, and insights for understanding eosinophil ontogeny, the effects of current precision therapeutics, and the regulation of eosinophil development and numbers in health and disease.

Differences in the Course, Diagnosis, and Treatment of Food Allergies Depending on Age-Comparison of Children and Adults.

Food allergy (FA) has become a common global public health issue, with a growing prevalence in the modern world and a significant impact on the lives of patients, their families, and caregivers. It affects every area of life and is associated with elevated costs. Food allergy is an adverse immune reaction that occurs in response to a given food. The symptoms vary from mild to severe and can lead to anaphylaxis. This is why it is important to focus on the factors influencing the occurrence of food allergies, specific diagnostic methods, effective therapies, and especially prevention. Recently, many guidelines have emphasized the impact of introducing specific foods into a child's diet at an early age in order to prevent food allergies. Childhood allergies vary with age. In infants, the most common allergy is to cow's milk. Later in life, peanut allergy is more frequently diagnosed. Numerous common childhood allergies can be outgrown by adulthood. Adults can also develop new IgE-mediated FA. The gold standard for diagnosis is the oral provocation test. Skin prick tests, specific IgE measurements, and component-resolved diagnostic techniques are helpful in the diagnosis. Multiple different approaches are being tried as possible treatments, such as immunotherapy or monoclonal antibodies. This article focuses on the prevention and quality of life of allergic patients. This article aims to systematize the latest knowledge and highlight the differences between food allergies in pediatric and adult populations.

Safety and Efficacy of VIT against Wasp Venom in Ultra-Rush Protocols in Patients Older Than 60 Years.

BACKGROUND: Allergen immunotherapy remains a widely recognized and widely used method for the treatment of selected allergic diseases. Currently, according to the European Academy Of Allergy and Clinical Immunology (EAACI) guidelines, venom immunotherapy (VIT) may be considered for patients over 60. Nevertheless, no separate studies have confirmed the efficacy and safety of this therapy. This study aimed to evaluate the short-term effectiveness of VIT against wasp allergens in an ultra-rush protocol for older patients compared to young patients. METHODS: Among the 113 patients included in this study, 51 were older than 60 years (Group A), and 62 formed the control "young group" (age range: 18-35 years). All patients were desensitized to wasp venom using the ultra-rush protocol according to Muller and aqueous solutions of vaccines containing wasp venom. A basophil activation test (Basotest, Orpegen Pharma, Germany) and intracutaneous tests with dilutions of wasp allergen and specific IgE to extract wasp venom were performed at the start and after six months of VIT. The safety of VIT was assessed on the basis of the international Mueller scale. RESULTS: One hundred and eleven patients with confirmed wasp allergies completed six months of VIT: 51 participants over 60 years of age (Group A) and 60 young people (Group B). No systemic adverse reactions were observed during the VIT induction phase. However, large local reactions were noted in 17% of older patients and 20% of young patients at a similar level (p > 0.05). During maintenance VIT, two mild grade I systemic reactions were confirmed in young patients. These symptoms resolved spontaneously. There were no such reactions in older patients. The effectiveness of VIT was tested using BAT. There was a statistically significant reduction in CD63 reactivity in 86% of patients in Group A, and a comparable and substantial decrease in 84% of young patients in Group B. According to the BAT test, the mean reductions in the area under the curve (AUC) after six months of VIT were significant (p < 0.05) and comparable between Groups A and B: -6.52 vs. 7.21. CONCLUSIONS: VIT against wasp venom is safe and effective in short-term observation, and is comparable to that used for young patients.

Increased CD123 + HLA-DR- Granulocytes in Allergic Rhinitis and Influence of Allergens on Expression of Cell Membrane Markers.

BACKGROUND: It is reported that CD123 + HLA-DR- cells in PBMC are basophils, and CD203c, CD63, and FcεRI molecules are activation markers of basophils. However, little is known of CD123 + HLA-DR-cells in blood granulocytes. OBJECTIVE: To investigate the presence of CD123 + HLA-DR- cells in the blood granulocytes and peripheral PBMC of patients with allergic rhinitis (AR), as well as the impact of allergens on the cell membrane markers of basophils. METHODS: Flow cytometry was used to detect the expression of the membrane molecules. RESULTS: While CD123 + HLA-DR- PBMCs are representative of basophils, their presence did not significantly change in patients with AR. In contrast, both the percentage and number of CD123 + HLA-DR- granulocytes, which make up only up to 50% of basophils, were significantly increased in patients with seasonal (sAR) and perennial AR (pAR). CD63+, CD203c+, and FcεRIα+ cells within CD123 + HLA-DR- granulocytes also showed enhanced activity in patients with AR. Allergen extracts from house dust mite allergen extract (HDME) and Artemisia sieversiana wild extract further increased the number of CD123 + HLA-DR- cells in granulocytes of sAR and pAR patients, as well as in PBMCs of pAR patients. CONCLUSIONS: The use of CD123 + HLA-DR- granulocytes and PBMC may not be sufficient for diagnosing AR. Allergens could potentially contribute to the development of AR by influencing the number of CD123 + HLA-DR- cells, as well as the expression of CD63, CD203c, and FcεRIαin these cells.

Novel insights into the ontogeny of basophils.

Basophils are the least common granulocytes, accounting for <1% of peripheral blood leukocytes. In the last 20 years, analytical tools for mouse basophils have been developed, and we now recognize that basophils play critical roles in various immune reactions, including the development of allergic inflammation and protective immunity against parasites. Moreover, the combined use of flow cytometric analyses and knockout mice has uncovered several progenitor cells committed to basophils in mice. Recently, advancements in single-cell RNA sequencing (scRNA-seq) technologies have challenged the classical view of the differentiation of various hematopoietic cell lineages. This is also true for basophil differentiation, and studies using scRNA-seq analysis have provided novel insights into basophil differentiation, including the association of basophil differentiation with that of erythrocyte/megakaryocyte and the discovery of novel basophil progenitor cells in the mouse bone marrow. In this review, we summarize the recent findings of basophil ontogeny in both mice and humans, mainly focusing on studies using scRNA-seq analyses.

PEGylated liposomes for diagnosis of polyethylene glycol allergy.

BACKGROUND: Polyethylene glycol (PEG) is a nonprotein polymer that is present in its native (unbound) form as an excipient in a range of products. It is increasingly being utilized clinically in the form of PEGylated liposomal medications and vaccines. PEG is the cause of anaphylaxis in a small percentage of drug reactions; however, diagnosis of PEG allergy is complicated by the variable and poor diagnostic performance of current skin testing protocols. OBJECTIVE: We assessed the diagnostic performance of PEGylated lipid medications as an alternative to currently described tests that use medications containing PEG excipients. METHODS: Nine patients with a strong history of PEG allergy were evaluated by skin testing with a panel of PEG-containing medications and with a PEGylated lipid nanoparticle vaccine (BNT162b2). Reactivity of basophils to unbound and liposomal PEG was assessed ex vivo, and specificity of basophil responses to PEGylated liposomes was investigated with a competitive inhibition assay. More detailed information is provided in this article's Methods section in the Online Repository available at www.jacionline.org. RESULTS: Despite compelling histories of anaphylaxis to PEG-containing medications, only 2 (22%) of 9 patients were skin test positive for purified PEG or their index reaction-indicated PEG-containing compound. Conversely, all 9 patients were skin test positive or basophil activation test positive to PEGylated liposomal BNT162b2 vaccine. Concordantly, PEGylated liposomal drugs (BNT162b2 vaccine and PEGylated liposomal doxorubicin), but not purified PEG2000, consistently induced basophil activation ex vivo in patients with PEG allergy but not in nonallergic controls. Basophil reactivity to PEGylated nanoparticles competitively inhibited by preincubation of basophils with native PEG2000. CONCLUSION: Presentation of PEG on the surface of a lipid nanoparticle increases its in vivo and ex vivo allergenicity, and improves diagnosis of PEG allergy.