The multifaceted role of mast cells in the pathogenesis of rheumatoid arthritis.

Mast cells (MC) are tissue duelling cells playing an active role in both innate and adaptive immune system. They act as first players in different microbial infections and exert a crucial role in allergy, chronic inflammation, fibrosis, and rheumatic diseases (RD), including rheumatoid arthritis (RA). MC are normally present in human synovia and they increase in the joints of RA patients, contributing to inflammatory and remodelling processes. Due to their great plasticity and multifunctionality, MC exert a wide range of roles in different stages of the disease. To date, the results obtained by in-vitro and in-vivo studies have contributed to better clarify the dynamic role of MC in local arthritis of RA and have improved our knowledge on different aspect of the disease. Although different mice models have been extensively used to investigate the contribution of MC in different stages of RA, those models often fail to reproduce the complexity and the heterogeneity of the human disease. Here, we provide an overview on different roles of MC in RA pathogenesis and how these cells might influence some clinical features of the disease.

Allergy Workup in the Diagnosis of COVID-19 Vaccines-Induced Hypersensitivity Reactions and Its Impact on Vaccination.

INTRODUCTION: Immediate and delayed hypersensitivity reactions (HSR) to COVID-19 vaccines are rare adverse events that need to be prevented, diagnosed, and managed in order to guarantee adherence to the vaccination campaign. The aims of our study were to stratify the risk of HSR to COVID-19 vaccines and propose alternative strategies to complete the vaccination. METHODS: 1,640 subjects were screened for vaccinal eligibility, according to national and international recommendations. Among them, we enrolled for allergy workup 152 subjects, 43 with HSR to COVID-19 vaccines and 109 at high risk of HSR to the first dose. In vivo skin tests with drugs and/or vaccines containing PEG/polysorbates were performed in all of them, using skin prick test and, when negative, intradermal tests. In a subgroup of patients resulted negative to the in vivo skin tests, the programmed dose of COVID-19 vaccine (Pfizer/BioNTech) was administered in graded doses regimen, and detection of neutralizing anti-spike antibodies was performed in these patients after 4 weeks from the vaccination, using the SPIA method. RESULTS: Skin tests for PEG/polysorbates resulted positive in only 3% (5/152) of patients, including 2 with previous HSR to COVID-19 vaccines and 3 at high risk of HSR to the first dose. Among the 147 patients with negative skin tests, 97% (143/147) were eligible for vaccination and 87% (124/143) of them received safely the programmed COVID-19 vaccine dose. Administration of graded doses of Pfizer/BioNTech vaccine were well tolerated in 17 out of 18 patients evaluated; only 1 developed an HSR during the vaccination, less severe than the previous one, and all developed neutralizing anti-spike antibodies after 4 weeks with values comparable to those subjects who received the vaccine in unfractionated dose. CONCLUSION: On the whole, the usefulness of the skin tests for PEG/polysorbates seems limited in the diagnosis of HSR to COVID-19 vaccines. Graded doses regimen (Pfizer/BioNTech) is a safe and effective alternative strategy to complete the vaccinal course.

Component-Resolved Diagnosis for Endotyping Patients with Chronic Rhinosinusitis with Nasal Polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a predominantly type 2 inflammation-mediated disease of the nasal mucosa and paranasal sinuses that often coexists with asthma. The role of atopy in the development and severity of CRSwNP is still a controversial issue. OBJECTIVE: The aim of our study was to propose a systematic allergy workup to identify atopic patients in the context of CRSwNP and to characterize their allergen sensitization profile (sources/molecules). METHODS: Patients with a diagnosis of CRSwNP (n = 97) were studied in the otorhinolaryngologist and allergy settings. Demographic and clinical data were collected for each patient. Different allergen sensitization profiles (sources/molecules) were evaluated in atopic CRSwNP patients by using component-resolved diagnosis (CRD). RESULTS: In our cohort of patients, the CRSwNP was frequently diagnosed during adulthood with significant impact on health-related quality of life. Asthma and atopy were the most common comorbidities with a prevalence of asthma in the atopic group. In CRSwNP patients sensitized to grass pollens and/or to house dust mites, the CRD analysis revealed a prevalence of sensitization to species-specific allergens of Phleum pratense (Phl p1, Phl p2, and Phl p5) or Dermatophagoides pteronyssinus (Der p1 and Der p2) rather than to cross-reactive ones. CONCLUSION: To define the allergen sensitization profile in atopic CRSwNP patients by CRD, it may be useful to better characterize type 2 inflammation, thus providing a personalized endotype-driven treatment.

Pathogenesis of rheumatoid arthritis: one year in review 2022.

The mechanisms underlying the pathogenesis of rheumatoid arthritis (RA) involve different components of the immune system. In subjects with genetic predisposition to develop RA, a tight interaction between cells and mediators of the innate and adaptive immune system leads to the amplification and perpetuation of inflammation and tissue remodelling. The research carried out in the last year in the field of RA has improved the current knowledge on the pathogenesis of the disease, and is potentially useful to develop new therapeutic approaches. Thus, in this review we provide an overview on the new insights into RA pathogenesis, resulting from a literature search of the data published in the last year.

One year in review 2021: pathogenesis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by local and systemic inflammation where the close interaction between immune cells and soluble mediators leads to amplification and perpetuation of inflammatory and remodelling processes. The research carried out in the last year in the field of RA has made it possible to identify new mechanisms involved in the pathogenesis of the disease, enabling the discovery of new potential therapeutic targets. Thus, in this review we summarise new insights in RA pathogenesis, resulting from a literature research date published in the last year.

One year in review 2020: pathogenesis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease influenced by both genetic, epigenetic and environmental factors. The discovery of new gene polymorphisms and their association with disease susceptibility have added new elements to better clarify RA pathogenesis. In the last year, important elements have been added to the current knowledge of mechanisms regulating innate and adaptive immunity in RA, leading to discovering new targets for the development of disease-modifying therapies. Thus, in this review we summarise the new insights resulting from a literature research data published in the last year.

One year in review 2019: pathogenesis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease influenced by both genetic and environmental factors. Over the last few years, particular attention has been given to novel genes and to the close interaction between genetic factors and epigenetic mechanisms. Research has also focused on the influence of environmental factors on disease development, and on new mechanisms of the innate and adaptive immune system that can influence the different stages of RA. However, there are still several aspects of the disease that need further investigation. Shedding some light on the different aspects of RA pathogenesis will help to improve the current diagnostic tools and to identify new targets for the development of disease-modifying therapies. Thus, in this review we summarise the new insights in RA pathogenesis, resulting from literature research data published in the last year.

One year in review 2018: pathogenesis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that primarily affects joints. The several mechanisms involved in the development of the disease are not completely understood. It has been proposed that different environmental factors, such as cigarette smoking, occupational and atmospheric agents act as trigger stimuli for the development of RA in genetically predisposed individuals, leading to synovial hyperplasia and bone destruction. The initial disease stage of RA is associated with alteration of innate and adaptive immune system with consequent production of autoantibodies, targeting various molecules including modified self-epitopes. In the following stages of the disease, both the innate (e.g. dendritic cells, macrophages and neutrophils) and adaptive immune cells (e.g. B and T lymphocytes) contribute to the amplification and perpetuation of the chronic inflammatory state. The recognition of key cells, mediators and mechanisms implicated in the pathogenesis of RA could provide the basis for the development of new and precise disease-modifying anti-rheumatic drugs. Therefore, we reviewed the literature of the last year in order to find the new insights in RA pathogenesis.

Efficacy and safety of omalizumab therapy in urticaria vasculitis.

Urticarial vasculitis (UV) is a small-vessel leukocytoclastic vasculitis characterized by different clinical manifestations ranging from long-lasting urticarial lesions to severe and potentially life-threatening multi-organ involvement. Omalizumab (OMA), anti-IgE recombinant humanized IgG1 monoclonal antibody, has been successfully used to treat few cases of severe and/or refractory UV. In this study we report our experience on 6 patients with refractory normocomplementemic UV successfully treated with anti-IgE therapy (OMA), suggesting that this biological therapy may be a safe and effective therapeutic option in UV.

Effectiveness of enzymatic hydrolysis for reducing the allergenic potential of legume by-products.

The interest in agri-food residues and their valorization has grown considerably, and many of them are today considered to be valuable, under-exploited sources of different compounds and notably proteins. Despite the beneficial properties of legumes by-products, there are also some emerging risks to consider, including their potential allergenicity. In this work the immunoreactivity of chickpea, pea, and white bean by-products was assessed, and whether the production of enzymatic hydrolysates can be an effective strategy to reduce this allergenic potential. The results presented clearly indicate that the efficiency of this strategy is strongly related to the enzyme used and the food matrix. All legume by-products showed immunoreactivity towards serum of legume-allergic patients. Hydrolysates from alcalase did not show residual immunoreactivity for chickpea and green pea, whereas hydrolysates from papain still presented some immunoreactivity. However, for white beans, the presence of antinutritional factors prevented a complete hydrolysis, yielding a residual immunoreactivity even after enzymatic hydrolysis with alcalase.

The Role of Skin Tests in the Prevention and Diagnosis of Hypersensitivity Reactions to Platinum Agents in Gynecological Cancer: A Single-Center Italian Retrospective Study.

BACKGROUND: Hypersensitivity reactions (HSR)s to platinum agents are increasing in frequency, due to their extensive use and repeated exposures in patients with increased life expectancy. The aims of our study are to analyze the frequency of both type I and type IV HSRs in patients with gynecological cancer treated with (CBDCA) carboplatin and/or (CDDP) cisplatin, to evaluate the role of skin tests in the diagnosis and prevention of HSRs. METHODS: From 2011 to 2018, we evaluated 124 consecutive female patients previously treated with CBDCA and/or CDDP for gynecological cancer. All patients, including those with and without HSR to previous platinum-based therapy, underwent in-vivo skin tests for platinum agents before starting the second or more therapeutic lines. To reduce the risk of false negative results, patients with a negative skin test at the first evaluation were re-tested after 3 weeks from the platinum re-exposure. RESULTS: Among the 124 patients evaluated, 58 (47%) experienced HSRs to at least one platinum agent: 35% were to CBDCA, 5% to CDDP, 7% to both. Fifty-six of the 58 HSRs were classified as immediate and two delayed. Skin tests confirmed an IgE-dependent mechanism in 67% of patients with immediate-HSRs to CBDCA and identified a cross-reactivity between platinum agents in 18% of patients. Moreover, among those who had never developed an HSRs during platinum-based therapy, in-vivo skin tests identified 12% of sensitized patients. CONCLUSIONS: On the basis of our findings, skin test for platinum agents is a simple and sensitive tool for the diagnosis and prevention of HSRs to CBDCA and/or CDDP and can be useful for detecting possible cross-reactivity among platinum agents.

Biomarkers In Chronic Spontaneous Urticaria: Current Targets And Clinical Implications.

Chronic urticaria (CU) is a mast cell-driven disease characterized by the development of wheals, angioedema, or both for more than 6 weeks. The two major sub-types are chronic spontaneous urticaria (CSU) and inducible urticaria. In the last decade different pathophysiological mechanisms, potentially responsible for the development of the disease, have been described. It is likely that the activation of mast cells and basophils in CSU can be the results of immune system dysregulation, activation of the inflammatory cascade, and of the extrinsic coagulation pathway. Some of the mediators involved in the pathophysiological mechanisms of CSU have recently been identified as potential biomarkers useful for the diagnosis, follow-up, and management of the disease, even if they are not yet available in clinical practice. Thus, in this review we discuss new insights in the mediators involved in the pathogenesis of CSU, highlighting their potential role as biomarkers in the activity and progression of the disease and response to therapies.

A novel DNA/histone H4 peptide complex detects autoantibodies in systemic lupus erythematosus sera.

BACKGROUND: The detection of anti-dsDNA antibodies is critical for the diagnosis and follow-up of systemic lupus erythematosus (SLE) patients. The presently available assays are characterized by a non-optimal specificity (solid phase assays) or sensitivity (Crithidia Luciliae immunofluorescence test (CLIFT)). To overcome the limits of CLIFT and solid phase chromatin assays, we explored the diagnostic potential of an assay based on plasmid DNA containing a highly bent fragment of 211 bp from Crithidia Luciliae minicircles, complexed with histone peptides. METHODS: Electrically neutral complexes of PK201/CAT plasmid (PK) DNA and histone 4 (H4) peptides were evaluated by electromobility shift assay. Complexes of H4 peptides and PK were absorbed to the solid phase to detect specific immunoglobulin G (IgG) in sera. Sera from 109 SLE patients, 100 normal healthy subjects, and 169 disease controls were tested. RESULTS: H4(14-34) containing the consensus sequence for DNA binding interacts with PK, retarding its migration. H4(14-34)/PK complexes were used to test sera by ELISA. Anti-H4-PK antibodies were detected in 56 % of SLE sera (more frequently in patients with skin or joint involvement) versus 5.9 % in disease controls; inhibition assays show that sera react with epitopes present on DNA or on the complex, not on the peptide. Antibody titer is correlated with European Consensus Lupus Activity Measurement (ECLAM) score and anti-complement component 1q (C1q) antibodies, negatively with C3 levels. Anti-H4-PK antibodies compared with CLIFT and solid phase dsDNA assays display moderate concordance. CONCLUSIONS: The H4/PK assay is a simple and reliable test which is useful for the differential diagnosis and evaluation of disease activity in SLE patients.