Predictors of Clonality and Underlying Mastocytosis in Mast Cell Activation Syndromes.

PURPOSE OF REVIEW: Mast cell (MC) activation can present with a wide range of symptoms. The mechanisms that cause such activation are varied. One of them is the presence of clonal MCs which is defined, within other possible changes, by the presence of a somatic, activating mutation in the KIT gene. The clinical course and prognosis of patients with this underlying disease may be different from other causes of MC activation (MCA). For this reason, it is important to early diagnose, or at least suspect, which patients with MCA are due to clonal MCs. RECENT FINDINGS: The diagnosis of clonality must be made in a comprehensive manner. However, this paper reviews chronologically each of the stages from the patient's first visit to the doctor's office which can be indicative of clonality: clinical presentation of MCA, physical examination, analytical determinations of tryptase, and/or KIT mutational analysis and bone involvement, among others. The different clonality predictive scores proposed are also reviewed and compared. Although the gold standard for the diagnosis of certainty of MC clonality is the performance of a bone marrow (BM) biopsy, there are clinical symptoms, signs, and biological parameters suggestive of clonality, as well as predictive scores, which can guide (or rule out) an early diagnosis and avoid unnecessary BM biopsies.

Clinical impact of the TPSAB1 genotype in mast cell diseases: A REMA study in a cohort of 959 individuals.

BACKGROUND: A close association between hereditary alpha-tryptasemia (HAT) and mast cell (MC) disorders has been previously reported. However, the relationship between HAT and the diagnostic subtypes and clinical features of MC disorders still remains to be established. OBJECTIVE: To determine the prevalence of HAT in healthy donors (HD) vs patients with different diagnostic subtypes of MC activation syndromes (MCAS) and mastocytosis, and its relationship with the clinical behavior of the disease. METHODS: A total of 959 subjects were studied including 346 healthy donors (HD), 464 mastocytosis, and 149 non-clonal MCAS patients. Molecular studies to assess the TPSAB1 genotype were performed, and data on serum baseline tryptase (sBT) and basal MC-mediator release episodes and triggers of anaphylaxis were collected. RESULTS: HAT was detected in 15/346 (4%) HD versus 43/149 (29%) non-clonal MCAS and 84/464 (18%) mastocytosis cases. Among mastocytosis, HAT was more frequently found in patients with MC-restricted KITD816V (21% vs. 10% among multilineage KITD816V patients; p = .008). Overall, median sBT was higher in cases presenting with HAT (28.9 vs. 24.5 ng/mL; p = .008), while no significant differences in sBT were observed among HAT+ mastocytosis patients depending on the presence of 1 vs. ≥2 extra copies of the α-tryptase gene (44.1 vs. 35.2 ng/mL, p > .05). In turn, anaphylaxis was more frequently observed in HAT+ versus HAT- mastocytosis patients (76% vs. 65%; p = .018), while HAT+ and HAT- patients who did not refer anaphylaxis as the presenting symptom (n = 308) showed a similar prevalence of subsequent anaphylaxis (35% vs. 36%, respectively). CONCLUSION: The frequency of HAT in MC disorders varies according to the diagnostic subtype of the disease. HAT does not imply a higher risk (and severity) of anaphylaxis in mastocytosis patients in whom anaphylaxis is not part of the presenting symptoms of the disease.

Structural Similarities, in Relation with the Cross-Reactivity, of Hymenoptera Allergenic Dipeptidyl Peptidases IV-An Overall Comparison Including a New Dipeptidyl Peptidase IV Sequence from Vespa velutina.

(1) Background: Dipeptidyl Peptidases IV (DPPIVs), present in many organisms, are minor components in the venoms of Hymenoptera, where they have been identified as cross-reactive allergenic molecules. Considering that the structure of homologous DPPIVs is well characterized, we aimed to explain which regions have higher similarity among these proteins and present a comparison among them, including a new Vespa velutina DPPIV sequence. Moreover, two cases of sensitization to DPPIVs in wasp- and honeybee-sensitized patients are presented. (2) Methods: Proteomic analyses have been performed on the venom of the Asian hornet Vespa velutina to demonstrate the sequence of its DPPIV (allergen named Vesp v 3, with sequence accession number P0DRB8, and with the proteomic data available via ProteomeXchange with the identifier PXD046030). A comparison performed through their alignments and analysis of the three-dimensional structure showed a region with higher similarity among Hymenoptera DPPIVs. Additionally, ImmunoCAP™ determinations (including specific inhibition experiments), as well as IgE immunoblotting, are performed to demonstrate the allergenicity of Api m 5 and Ves v 3. (3) Results and Conclusions: The data presented demonstrate that the similarities among Hymenoptera DPPIVs are most likely localized at the C-terminal region of these enzymes. In addition, a higher similarity of the Vespa/Vespula DPPIVs is shown. The clinical cases analyzed demonstrated the allergenicity of Api m 5 and Ves v 3 in the sera of the allergic patients, as well as the presence of this minor component in the preparations used in venom immunotherapy.

Value of the Lymphocyte Transformation Test for the Diagnosis of Drug-Induced Hypersensitivity Reactions in Hospitalized Patients with Severe COVID-19.

In the first wave of COVID-19, up to 20% of patients had skin lesions with variable characteristics. There is no clear evidence of the involvement of the SARS-CoV-2 virus in all cases; some of these lesions may be secondary to drug hypersensitivity. To analyze the possible cause of the skin lesions, we performed a complete allergology study on 11 patients. One year after recovery from COVID-19, we performed a lymphocyte transformation test (LTT) and Th1/Th2 cytokine secretion assays for PBMCs. We included five nonallergic patients treated with the same drugs without lesions. Except for one patient who had an immediate reaction to azithromycin, all patients had a positive LTT result for at least one of the drugs tested (azithromycin, clavulanic acid, hydroxychloroquine, lopinavir, and ritonavir). None of the nonallergic patients had a positive LTT result. We found mixed Th1/Th2 cytokine secretion (IL-4, IL-5, IL-13, and IFN-γ) in patients with skin lesions corresponding to mixed drug hypersensitivity type IVa and IVb. In all cases, we identified a candidate drug as the culprit for skin lesions during SARS-CoV-2 infection, although only three patients had a positive drug challenge. Therefore, it would be reasonable to recommend avoiding the drug in question in all cases.

Disease Spectrum of Anaphylaxis Disorders.

Anaphylaxis results from massive mast cell activation. Mechanisms of mast cell activation may involve IgE- and non-IgE-mediated triggers, clonal mast cell disease, or be idiopathic and may be modified by several factors including but not restricted to hormonal status, stress, heritable factors, mast cell burden, and simultaneous exposure to more than 1 factor. Patients with recurrent anaphylaxis with a nonidentifiable trigger present a particular challenge in diagnosis and management. Presence of clonal disease may be suggested by hypotensive episodes with urticaria and angioedema, and high baseline tryptase levels. A number of scoring systems have been developed to identify patients who are at high risk to have underlying mastocytosis. This review provides an overview of anaphylaxis disorders and our current understanding of their mechanisms of action, evaluation, and management.

Optimisation of the quality of care for patients with severe asthma: ASfarMA project.

Severe asthma has an important impact on patients and healthcare resources. Recently, the new specific treatments have defined a new scenario in which person-focused care and specialist multidisciplinary teams are necessary. Our Severe Asthma Unit (SAU) started the ASfarMA project along with an external human-centered design company to understand patients' vision of their illness, treatment, and healthcare experience, and to define the ideal SAU by performing a core group session, in-depth semistructured interviews and co-creation workshop. Herein, a series of tips classified as either 'transformative solutions' or 'quick wins', according to a value versus effort matrix are presented. Successful implementation of the proposed solutions will be valuable for patients and healthcare professionals, optimising patient care and resources. These findings can also be helpful to other SAUs or other humanisation projects involving complex, chronic and multidisciplinary pathologies.

Personalized diagnostic approach and indirect quantification of extravasation in human anaphylaxis.

BACKGROUND: Anaphylaxis is the most acute and life-threatening manifestation of allergic disorders. Currently, there is a need to improve its medical management and increase the understanding of its molecular mechanisms. This study aimed to quantify the extravasation underlying human anaphylactic reactions and propose new theragnostic approaches. METHODS: Molecular determinations were performed in paired serum samples obtained during the acute phase and at baseline from patients presenting with hypersensitivity reactions. These were classified according to their severity as Grades 1, 2 and 3, the two latter being considered anaphylaxis. Tryptase levels were measured by ImmunoCAP, and serum protein concentration was quantified by Bradford assay. Human serum albumin (HSA) and haemoglobin beta subunit (HBB) levels were determined by Western blot and polyacrylamide gel electrophoresis, respectively. RESULTS: A total of 150 patients were included in the study. Of them, 112 had experienced anaphylaxis (83 and 29 with Grade 2 and 3 reactions, respectively). Tryptase diagnostic efficiency substantially improved when considering patients' baseline values (33%-54%) instead of the acute value threshold (21%). Serum protein concentration and HSA significantly decreased in anaphylaxis (p < .0001). HSA levels dropped with the severity of the reaction (6% and 15% for Grade 2 and 3 reactions, respectively). Furthermore, HBB levels increased during the acute phase of all hypersensitivity reactions (p < .0001). CONCLUSIONS: For the first time, the extravasation underlying human anaphylaxis has been evaluated based on the severity of the reaction using HSA and protein concentration measurements. Additionally, our findings propose new diagnostic and potential therapeutic approaches for this pathological event.

Safety and Effectiveness of a Single Multiallergen Subcutaneous Immunotherapy in Polyallergic Patients.

BACKGROUND: As the number of allergic sensitizations increases the severity of allergic respiratory diseases worsens. Multiple monoallergen immunotherapy can be accompanied by poor treatment adherence and high costs, single multiallergen immunotherapy needs to prove efficacy whilst maintaining a good safety profile. METHODS: Observational, retrospective, multicenter study using a 2-pollen single undiluted multiallergen subcutaneous immunotherapy (SCIT) in routine clinical practice in Spain. Patients with rhinoconjunctivitis, with/without controlled asthma, sensitized to grass, olive, Parietaria, Cupressus, plane tree and/or Salsola pollen were included. Primary and secondary clinical efficacy endpoints were quality of life (mini Rhinitis Quality of Life Questionnaire (miniRQLQ)) and visual analogue scale (VAS) respectively. All adverse events were documented. RESULTS: Ten centers included 97 patients, median age 32 years. SCIT treatment included combinations of grass mix with olive, Parietaria, Cupressus, plane tree or Salsola or olive with Parietaria, Cupressus or Salsola. The mean duration of SCIT was 1.8 years with a high treatment adherence (73%). Significant improvement in quality of life, nasal and ocular symptoms, activity limitations and practical problems (p< 0.0001) and other symptoms (p= 0.024) was observed. Most patients did not develop asthma-like symptoms and a significant improvement of all allergic symptom severity was perceived. VAS showed a significant improvement in rhinoconjunctivitis and asthma by patients and physicians. Twenty-nine patients experienced adverse reactions, 25 had local and 6 had systemic reactions. CONCLUSIONS: Single undiluted multiallergen SCIT treatment of two different pollens is efficacious and safe in both children and adults, showing that it is a suitable option for the treatment of polyallergic patients.

Feasibility and Acceptability of an Asthma App to Monitor Medication Adherence: Mixed Methods Study.

BACKGROUND: Poor medication adherence is a major challenge in asthma, and objective assessment of inhaler adherence is needed. The InspirerMundi app aims to monitor adherence while providing a positive experience through gamification and social support. OBJECTIVE: This study aimed to evaluate the feasibility and acceptability of the InspirerMundi app to monitor medication adherence in adolescents and adults with persistent asthma (treated with daily inhaled medication). METHODS: A 1-month mixed method multicenter observational study was conducted in 26 secondary care centers from Portugal and Spain. During an initial face-to-face visit, physicians reported patients' asthma therapeutic plan in a structured questionnaire. During the visits, patients were invited to use the app daily to register their asthma medication intakes. A scheduled intake was considered taken when patients registered the intake (inhaler, blister, or other drug formulation) by using the image-based medication detection tool. At 1 month, patients were interviewed by phone, and app satisfaction was assessed on a 1 (low) to 5 (high) scale. Patients were also asked to point out the most and least preferred app features and make suggestions for future app improvements. RESULTS: A total of 107 patients (median 27 [P25-P75 14-40] years) were invited, 92.5% (99/107) installed the app, and 73.8% (79/107) completed the 1-month interview. Patients interacted with the app a median of 9 (P25-P75 1-24) days. At least one medication was registered in the app by 78% (77/99) of patients. A total of 53% (52/99) of participants registered all prescribed inhalers, and 34% (34/99) registered the complete asthma therapeutic plan. Median medication adherence was 75% (P25-P75 25%-90%) for inhalers and 82% (P25-P75 50%-94%) for other drug formulations. Patients were globally satisfied with the app, with 75% (59/79) scoring ≥4,; adherence monitoring, symptom monitoring, and gamification features being the most highly scored components; and the medication detection tool among the lowest scored. A total of 53% (42/79) of the patients stated that the app had motivated them to improve adherence to inhaled medication and 77% (61/79) would recommend the app to other patients. Patient feedback was reflected in 4 major themes: medication-related features (67/79, 85%), gamification and social network (33/79, 42%), symptom monitoring and physician communication (21/79, 27%), and other aspects (16/79, 20%). CONCLUSIONS: The InspirerMundi app was feasible and acceptable to monitor medication adherence in patients with asthma. Based on patient feedback and to increase the registering of medications, the therapeutic plan registration and medication detection tool were redesigned. Our results highlight the importance of patient participation to produce a patient-centered and engaging mHealth asthma app.

Increased TPSAB1 Copy Number in a Family With Elevated Basal Serum Levels of Tryptase.

Background: Some recent familial studies have described a pattern of autosomal dominant inheritance for increased basal serum tryptase (BST), but no correlation with mRNA expression and gene dose have been reported. Objective: We analyzed TPSAB1 mRNA expression and gene dose in a four-member family with high BST and in two control subjects. Methods: Blood samples were collected from the family and control subjects. Complete morphologic, immunophenotypical, and molecular bone marrow mast cell (MC) studies were performed. mRNA gene expression and gene dose were performed in a LightCycler 480 instrument. Genotype and CNV were performed by quantitative real-time digital PCR (qdPCR). Results: CNV analysis revealed a hereditary copy number gain genotype (3ß2α) present in all the family members studied. The elevated total BST in the family members correlated with a significant increase in tryptase gene expression and dose. Conclusions and Clinical Relevance: We present a family with hereditary α-tryptasemia and elevated BST which correlated with a high expression of tryptase genes and an increased gene dose. The family members presented with atypical MC-mediator release symptoms or were even asymptomatic. Clinicians should be aware that elevated BST does not always mean an MC disorder.