The Ambiguity in Immunology

In the present article, we discuss the various ambiguous aspects of the immune system that render this complex biological network so highly flexible and able to defend the host from different external invaders. This ambiguity stems mainly from the property of the immune system to be both protective and harmful. Immunity cannot be fully protective without producing a certain degree of damage (immunopathology) to the host. The balance between protection and tissue damage is, therefore, critical for the establishment of immune homeostasis and protection. In this review, we will consider as ambiguous, various immunological tactics including: (a) the opposing functions driving immune responses, immune-regulation, and contra-regulation, as well as (b) the phenomenon of chronic immune activation as a result of a continuous cross-presentation of apoptotic T cells by dendritic cells. All these plans participate principally to maintain a state of chronic low-level inflammation during persisting infections, and ultimately to favor the species survival

New insights into pathogenesis and treatment of anca-associated vasculitis. autoantibodies and beyond

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of rare systemic diseases affecting small-caliber vessels. The damage caused by AAV mainly involves the lung and kidneys. AAV includes three different types: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Although the different phenotypic forms of AAV share common features, recent studies have shown that there are significant differences in terms of pathogenetic mechanisms involving both the adaptive and innate immune systems. Advances in our understanding of pathogenesis have enabled the development of immuno-targeted therapies. This review illustrates the characteristics of the various forms of AAV and the new therapies available for this disease that can have lethal consequences if left untreated

The double game played by Th17 cells in infection: host defense and immunopathology

T-helper 17 (Th17) cells represent a subpopulation of CD4+ T lymphocytes that play an essential role in defense against pathogens. Th17 cells are distinguished from Th1 and Th2 cells by their ability to produce members of the interleukin-17 (IL-17) family, namely IL-17A and IL-17F. IL-17 in turn induces several target cells to synthesize and release cytokines, chemokines, and metalloproteinases, thereby amplifying the inflammatory cascade. Th17 cells reside predominantly in the lamina propria of the mucosa. Their main physiological function is to maintain the integrity of the mucosal barrier against the aggression of infectious agents. However, in an appropriate inflammatory microenvironment, Th17 cells can transform into immunopathogenic cells, giving rise to inflammatory and autoimmune diseases. This review aims to analyze the complex mechanisms through which the interaction between Th17 and pathogens can be on the one hand favorable to the host by protecting it from infectious agents, and on the other hand harmful, potentially generating autoimmune reactions and tissue damage

biological agents in the treatment of uveitis

Inflammatory uveitis is a difficult condition to treat. Recently, a new class of drugs obtained by a biological process and therefore defined as "biologics" has been successfully used in the treatment of immunemediated rheumatic diseases. These drugs target different pro-inflammatory cytokines including tumor necrosis factor-α, interleukin-1 and interleukin-6, or immune effector cells including B and T lymphocytes. Their use has been then extended to different forms of uveitis resistant to standard therapy in small uncontrolled trials, with general and unexpected efficacy. The present review analyzes the literature on treatment of uveitis with the biologics currently available for the treatment of inflammatory rheumatic diseases. We used PubMed search engine as the main source of information. Among the papers included in the reference list, a particular emphasis was given on articles published during the last 5 years

Chloroquine enhances human CD8+ T cell responses against soluble antigens in vivo

The presentation of exogenous protein antigens in a major histocompatibility complex class I–restricted fashion to CD8+ T cells is called cross-presentation. We demonstrate that cross-presentation of soluble viral antigens (derived from hepatitis C virus [HCV], hepatitis B virus [HBV], or human immunodeficiency virus) to specific CD8+ T cell clones is dramatically improved when antigen-presenting dendritic cells (DCs) are pulsed with the antigen in the presence of chloroquine or ammonium chloride, which reduce acidification of the endocytic system. The export of soluble antigen into the cytosol is considerably higher in chloroquine-treated than in untreated DCs, as detected by confocal microscopy of cultured cells and Western blot analysis comparing endocytic and cytosolic fractions. To pursue our findings in an in vivo setting, we boosted groups of HBV vaccine responder individuals with a further dose of hepatitis B envelope protein vaccine with or without a single dose of chloroquine. Although all individuals showed a boost in antibody titers to HBV, six of nine individuals who were administered chloroquine showed a substantial CD8+ T cell response to HBV antigen, whereas zero of eight without chloroquine lacked a CD8 response. Our results suggest that chloroquine treatment improves CD8 immunity during vaccination

Adalimumab and ABP 501 in the Treatment of a Large Cohort of Patients with Inflammatory Arthritis: A Real Life Retrospective Analysis

The recent introduction of ABP 501, an adalimumab biosimilar, in the treatment of rheumatic diseases was supported by a comprehensive comparability exercise with its originator. On the other hand, observational studies comparing adalimumab and ABP 501 in inflammatory arthritis are still lacking. The main aim of this study is to compare the clinical outcomes of the treatment with adalimumab, both the originator and ABP 501, in a large cohort of patients affected by autoimmune arthritis in a real life setting. We retrospectively analysed the baseline characteristics and the retention rate in a cohort of patients who received at least a course of adalimumab (originator or ABP 501) from January 2003 to December 2020. We stratified the study population according to adalimumab use: naive to original (oADA), naive to ABP 501 (bADA) and switched from original to ABP 501 (sADA). The oADA, bADA and sADA groups included, respectively, 724, 129 and 193 patients. In each group, the majority of patients had a diagnosis of rheumatoid arthritis. The total observation period was 9805.6 patient-months. The 18-month retentions rate in oADA, bADA and sADA was, respectively, 81.5%, 84.0% and 88.0% (p > 0.05). The factors influencing the adalimumab retention rate were an axial spondylarthritis diagnosis (Hazard Ratio (HR) 0.70; p = 0.04), switch from oADA to ABP 501 (HR 0.53; p = 0.02) and year of prescription (HR 1.04; p = 0.04). In this retrospective study, patients naive to the adalimumab originator and its biosimilar ABP 501 showed the same retention rate. Patients switching from the originator to biosimilar had a higher retention rate, even though not statistically significant, when compared to naive

Combination of chemotherapy and PD-1 blockade induces T cell responses to tumor non-mutated neoantigens

Here, we developed an unbiased, functional target-discovery platform to identify immunogenic proteins from primary non-small cell lung cancer (NSCLC) cells that had been induced to apoptosis by cisplatin (CDDP) treatment in vitro, as compared with their live counterparts. Among the multitude of proteins identified, some of them were represented as fragmented proteins in apoptotic tumor cells, and acted as non-mutated neoantigens (NM-neoAgs). Indeed, only the fragmented proteins elicited effective multi-specific CD4+ and CD8+ T cell responses, upon a chemotherapy protocol including CDDP. Importantly, these responses further increased upon anti-PD-1 therapy, and correlated with patients’ survival and decreased PD-1 expression. Cross-presentation assays showed that NM-neoAgs were unveiled in apoptotic tumor cells as the result of caspase-dependent proteolytic activity of cellular proteins. Our study demonstrates that apoptotic tumor cells generate a repertoire of immunogenic NM-neoAgs that could be potentially used for developing effective T cell-based immunotherapy across multiple cancer patients

Baseline Ultrasound Assessment Improves the Response to Apremilast in Patients with Psoriatic Arthritis: Results from a Multicentre Study

ound: Psoriatic arthritis (PsA) phenotypes show different responses to the many available drugs. For a tailored medicine, it is important to choose the most effective treatment according to patients’ characteristics. Apremilast is recommended in PsA with moderate activity. In clinical practice, the most suitable PsA patients for apremilast are those affected by the peripheral oligoarticular arthritis. However, it is not so straightforward to definitely identify this phenotype. Musculoskeletal ultrasound (MUS) is a good tool for detecting the joints actually involved by PsA. The aim of this study is to verify if MUS assessment is useful in selecting the best PsA responders to apremilast. Methods: The following data of all consecutive PsA patients from 15 centres were recorded: anamnestic data, disease activity, PsA phenotype, apremilast treatment duration and reason of suspension. MUS assessment before apremilast treatment was the criteria which clustered patients in two groups. Apremilast retention rate estimate the drug’s effectiveness. The Cox analysis revealed the risk factors associated with treatment persistence. Mann-Whitney U and Chi-squared tests assessed the intergroup differences. Results: Only 40% of 356 patients (M:F: 152/204; median age 60 yrs) received MUS examination. In MUS group the moderate disease (median DAPSA 22.9 vs 26.9; p=0.0006) and the oligo-articular phenotype (63.6% vs 36.1%, p<0.0001) were more common. The retention rate was higher in MUS group (HR 0.55 IC95% 0.32-0.94; p=0.03). Conclusion: In apremilast treated PsA patients, baseline MUS assessment is related to an increased retention rate. MUS may identify patients’ characteristics favourable to apremilast response

Predictors of DAPSA Response in Psoriatic Arthritis Patients Treated with Apremilast in a Retrospective Observational Multi-Centric Study (2023-02-07)

Background: To date, only a few real-world-setting studies evaluated apremilast effectiveness in psoriatic arthritis (PsA). The aims of this retrospective observational study are to report long-term Disease Activity Index for Psoriatic Arthritis (DAPSA) response of apremilast in PsA patients and to analyze the predictors of clinical response. Methods: All PsA consecutive patients treated with apremilast in fifteen Italian rheumatological referral centers were enrolled. Anamnestic data, treatment history, and PsA disease activity (DAPSA) at baseline, 6 months, and 12 months were recorded. The Mann–Whitney test and chi-squared tests assessed the differences between independent groups, whereas the Wilcoxon matched pairs signed-rank test assessed the differences between dependent samples. Logistic regressions verified if there were factors associated with achievement of DAPSA low disease activity or remission at 6 and 12 months. Results: DAPSA low disease activity or remission rates at 6 and 12 months were observed, respectively, in 42.7% (n = 125) and 54.9% (n = 161) patients. Baseline DAPSA was inversely associated with the odds of achieving low disease activity or remission at 6 months (odds ratio (OR) 0.841, 95% confidence interval (CI) 0.804–0.879; p < 0.01) and at 12 months (OR 0.911, 95% CI 0.883–0.939; p < 0.01). Conclusions: Almost half of the PsA patients receiving apremilast achieved DAPSA low disease activity or remission at 6 and 12 months. The only factor associated with achievement of low disease activity or remission at both 6 and 12 months was baseline DAPSA

Influence of safety warnings on the prescribing attitude of JAK 2inhibitors for rheumatoid arthritis in Italy

The Janus kinase inhibitors (JAKi) tofacitinib (TOFA), baricitinib (BARI), upadacitinib (UPA) and 74 filgotinib (FILGO) are effective drugs for the treatment of rheumatoid arthritis. However, the US 75 Food & Administration (FDA) raised concerns on the safety of TOFA after its approval. This 76 prompted the European Medicines Agency (EMA) to issue two safety warnings for limiting TOFA 77 use then extended in a third warning to all Jaki in patients at high risk of developing serious adverse 78 events (SAE). These included thrombosis, major adverse cardiac events (MACE) and cancer. Thepurpose of this work was to analyze how the first two safety warnings from EMA affected the pre- 80 scribing of Jaki by rheumatologists in Italy. All patients with rheumatoid arthritis who had been 81 prescribed JAKi for the first time in a 36-month period from July 1, 2019, to June 30, 2022 were con- 82 sidered. Data were obtained from the medical records of 29 Italian tertiary referral rheumatology 83 centers. Patients were divided into three groups of 4 months each, depending on whether the JAKi 84 prescription had occurred before the EMA's first safety alert (July 1-October 31, 2019, Group 1), 85 between the first and second alerts (November 1, 2019-February 29, 2020, Group 2), or between the 86 second and third alerts (March 1, 2021-June 30, 2021, Group 3). Percentage and absolute changes in 87 patients prescribed the individual JAKi were analyzed. Differences among the three Groups of pa- 88 tients in demographic and clinical characteristics were also assessed. A total of 864 patients were 89 prescribed a JAKi during the entire period considered. Of these, 343 were identified in Group 1, 233 90 in Group 2 and 288 in Group 3. An absolute reduction of 32% was observed in the number of patients 91 prescribed a JAKi between Group 1 and Group 2 and 16% between Group 1 and Group 3. In contrast, 92 there was a 19% increase in the prescription of a JAKi in patients between Group 2 and Group 3. In 93 the first Group, BARI was the most prescribed drug (227 prescriptions, 66.2% of the total), followed 94 by TOFA (115, 33.5%) and UPA (1, 0.3%). In the second Group, the most prescribed JAKi was BARI 95 (147, 63.1%), followed by TOFA (65, 27.9%) and UPA (33, 11.5%). In the third Group, BARI was still 96 the most prescribed JAKi (104 prescriptions, 36.1%), followed by UPA (89, 30.9%), FILGO (89, 21.5%) 97 and TOFA (33, 11.5%). The number of patients prescribed TOFA decreased significantly between 98 Group 1 and Group 2 and between Group 2 and Group 3 (p ˂ 0.01). Patients who were prescribed 99 BARI decreased significantly between Group 1 and Group 2 and between Group 2 and Group 3 (p 100 ˂ 0.01). In contrast, patients prescribed UPA increased between Group 2 and Group 3 (p ˂ 0.01). 101 These data suggest that the warnings issued for TOFA were followed by a reduction in total JAKi 102 prescriptions. However, the more selective JAKi (UPA and FILGO) were perceived by prescribers 103 as favorable in terms of risk/benefit ratio and their use gradually increased at the expense of the 104 other molecules