Efficacy and Safety of Low-Dose Interleukin 2 for Primary Sjögren Syndrome: A Randomized Clinical Trial

Clinical targeted treatment in Sjogren's disease: A systematic literature review for an evidence-based medicine approach

Sjögren's disease is a systemic autoimmune disease that primarily affects the exocrine glands, causing the main symptoms of xerostomia and xerophthalmia. In about half of the patients, it also causes systemic symptoms, which can potentially involve any organ or system. To date, the management of these patients is particularly complex due to the lack of recognized and approved therapies for the disease, except for medications used as symptomatic treatment for dryness. Due to the limited evidence available, therapeutic decisions in daily practice are frequently based on a combination of expert opinions and personal experience, which can vary significantly between clinicians. On these bases, we performed as systematic literature review critically analyzing the results of the previous trials, unpacking the single domains of ESSDAI, to evaluate if there are treatments significantly effective in some manifestations of the disease.

Route of Application and Dose Evaluation of Dental Pulp Stem Cells for the Treatment of Sialadenitis Caused by Sjögren's Syndrome: A Preclinical Study

Background: Sjögren's syndrome (SS) is an autoimmune disorder characterized by sicca syndrome and/or systemic manifestations. In this study, non-obese diabetic (NOD) mice were used as an animal model for studying SS, to evaluate the optimal administration route and dose range of dental pulp stem cells (DPSCs) in the treatment of sialadenitis caused by SS. Methods: Different doses of DPSCs were transplanted into the submandibular glands (SMGs) of 14-week-old NOD mice through two different methods: injection or retrograde perfusion through the catheter orifice into the SMG. At 21 weeks of age, the saliva flow rate (SFR), ectopic lymphocytes, and CD4+ T-cell infiltration were measured. Tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in the glandular tissues were also quantitatively detected. Results: Compared with untreated and PBS-injected controls, different-dose groups of the two administration methods showed an increased saliva flow rate of NOD mice to varying degrees, reduced infiltration of lymphocytes and CD4+ T cells in the SMG, and decreased IFN-γ/TNF-α levels. Finally, we compared these two administration routes and found that the perfusion of 2 × 105 DPSCs presents good therapeutic effects. Conclusions: DPSC perfusion through the catheter orifice is a simple and effective treatment method, which is worthy of further investigation through clinical trials.

Low-dose interleukin 2 therapy halts the progression of post-streptococcal autoimmune complications in a rat model of rheumatic heart disease

Acute rheumatic fever (ARF) is an autoimmune disease triggered by antibodies and T cells targeting the group A Streptococcus (GAS, Strep A) bacterium, often leading to rheumatic heart disease (RHD) and Sydenham's chorea. Long-term monthly penicillin injections are recognized as a cornerstone of public health programs to prevent Strep A reinfection and progression of ARF. However, compliance is poor, and better tools are required to slow disease progression. Preclinical evidence suggests that this can be achieved. Using a rat model that replicates post-streptococcal autoimmune complications, we explored the potential of low-dose interleukin-2 (LD-IL-2) as an immunotherapeutic intervention for ARF/RHD. In this model, injections of recombinant M protein from Strep A type 5 (rM5) to Lewis rats induce cardiac tissue inflammation, conduction abnormalities, and cross-reactive antibodies against cardiac and brain proteins central to disease pathogenesis. In animals injected with rM5 and treated with LD-IL-2, no cardiac functional or histological changes was observed. LD-IL-2 therapy effectively reduced the production of cross-reactive antibodies raised against host proteins and significantly increased regulatory T cells in the mediastinal lymph nodes. These novel findings suggest that LD-IL-2 will be an effective immunotherapeutic agent for treating ARF and has the potential to replace the standard monthly penicillin injections.

IMPORTANCE

Post-streptococcal autoimmune syndromes, including acute rheumatic fever, rheumatic heart disease, and Sydenham's chorea, represent a significant yet often under-recognized health and economic burden. This is especially true in low-income countries and among Indigenous populations in high-income nations, where the disease burden is most severe. These conditions arise from an autoimmune response to group A Streptococcus infections, leading to long-term health complications, disability, and premature death. Despite their widespread impact, no vaccine is currently available to prevent reinfections, and no specific therapy exists to treat the resulting autoimmune process. This study uses a rat model of rheumatic heart disease to evaluate the potential of low-dose interleukin 2 therapy in improving clinical outcomes and reducing the incidence of autoimmune diseases triggered by streptococcal infections.

Genetic insight into dissecting the immunophenotypes and inflammatory profiles in the pathogenesis of Sjogren syndrome

BACKGROUND

Sjogren syndrome (SS) is a chronic systemic autoimmune disease and its pathogenesis often involves the participation of numerous immune cells and inflammatory factors. Despite increased researches and studies recently focusing on this area, it remains to be fully elucidated. We decide to incorporate genetic insight into investigation of the causal link between various immune cells, inflammatory factors and pathogenesis of Sjogren syndrome (SS).

METHODS

Our study leveraged the genetic variants of multi-omics statistics extracted from genome-wide association study (GWAS), the University of Bristol and the FinnGen study. We performed a bidirectional Mendelian randomization and mediation study based on randomly allocated instrumental variables to infer causality, followed by external validation with UK Biobank data and Bayesian colocalization.

RESULTS

We demonstrated that an elevated level of CD27 on IgD + CD24 + B cell, a subset of B cells expressing both IgD and CD24, was associated with a higher risk of SS (OR = 1.119, 95% CI: 1.061-1.179, P < 0.001), while CD3 on CD45RA + CD4 + Treg was a protective factor (OR = 0.917, 95%CI: 0.877-0.959, P < 0.001). Results of meta-analysis and colocalization further supported the significant results identified in the primary analysis. A total of 4 inflammatory cytokines and 7 circulating proteins exhibited potential causal relationships with SS despite no significant result achieved after FDR correction. Finally, results of mediation analysis indicated that CD40L receptor levels had significant mediating effects (β = 0.0314, 95% CI: 0.0004-0.0624, P = 0.0471) at a mediation proportion of 28% (95% CI: 0.364%-55.6%) in causal relationship between CD27 on IgD + CD24 + B cell and SS.

CONCLUSIONS

By providing a novel genetic insight into unveiling the roles of autoimmunity and inflammation in Sjogren syndrome, our findings may potentially lead to identifying new clinical biomarkers for disease monitoring and therapeutic targets that offer more effective alternatives for treating this condition. Therefore, our study may provide valuable evidence for future clinical intervention and targeted immunotherapy.

Metabolic impact of low dose IL-2 therapy for primary Sjögren's Syndrome in a double-blind, randomized clinical trial

OBJECTIVES

Low-dose interleukin 2 (Ld-IL2) is increasingly being explored as an immune-modulating treatment for autoimmune diseases which mainly affect T cell subsets. This study investigates the metabolic effects of Ld-IL2 therapy in patients with primary Sjögren's syndrome (pSS).

METHOD

A total of 60 patients were recruited to conduct a double-blind, randomized clinical trial. Of these patients, 50% (30/60) received Ld-IL2 therapy along with standard treatment for 12 weeks, followed by 12 weeks of follow-up. The effectiveness was evaluated by Sjögren's Tool for Assessing Response (STAR). An untargeted analysis was performed to profile hydrophilic metabolites.

RESULTS

Metabolic profiling revealed significant alterations post-treatment, notably in metabolites like acetyl-CoA, ascorbic acid, and glutathione, which are beneficial in managing autoimmune diseases. In addition, the levels of metabolite accumulation were correlated with variations in immune cell subsets (p < 0.05), particularly Tregs. Moreover, patients exhibiting a specific metabolic profile, including lower serum levels of isoleucine, ADP, Thymidine 5'-triphosphate, and other metabolites, had a high response rate (91.7%-98.6%), as indicated by the receiver operating characteristic (ROC) curve.

CONCLUSIONS

These findings suggest that Ld-IL2 therapy influences metabolic pathways in pSS, offering insights into the systemic effects of Ld-IL2 therapy beyond immune modulation.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov number, NCT02464319. Key Points • Metabolic alteration in pSS is significantly associated with Ld-IL2 therapy. • Metabolic changes correlate with variations in immune cell subsets, particularly Tregs. • Metabolic profiling could be a valuable tool in guiding Ld-IL2 therapy choices for pSS patients.

Predictive biomarkers for low-dose IL-2 therapy efficacy in systemic lupus erythematosus: a clinical analysis

BACKGROUND

Low-dose IL-2 (Ld-IL2) has shown favorable therapeutic effects in systemic lupus erythematosus (SLE) therapy. However, previous clinical trials reported an SLE Responder Index-4 (SRI-4) response rate of 65.52%-68%, with approximately half failing to achieve the primary endpoint by week 24. Our study aims to determine the real-world use of Ld-IL2 and to identify determinants of its effectiveness in SLE.

METHODS

We pooled data from 342 SLE patients undergoing sequential Ld-IL2 treatment, with 314 persisting for over 3 months were included in effectiveness and prediction analyses. All patients were categorized into responder (n = 136) and non-responder group (n = 178) according to SRI-4. Lupus Low Disease Activity State (LLDAS) was also analyzed to validate our results.

RESULTS

Rash, lower complement 3 (C3), and renal involvement including urine protein, urine occult blood and urine casts emerged as prominent predictors of achieving SRI-4. Adjusting for baseline values using the ratio of change to baseline revealed significant differences in CD4 + T cell immune profiles between responders and non-responders. ROC analysis confirmed a satisfactory performance of rash, renal involvement, percentage change of CD4 + T cells, and C3 in predicting SRI-4, yielding an AUC of 0.933. LLDAS analysis showed that hematological involvements and lower CLA + Treg were potent predictive markers in LLDAS attainment. Conversely, renal involvement failed to have significant association in achieving LLDAS. The analysis of background therapy in SLE patients showed that MMF was more likely to reach the SRI-4 response with the combination of Ld-IL2.

CONCLUSIONS

These findings uncovered the predictors of Ld-IL2 treatment efficacy in SLE patients and provided guidance to physicians for rational utilization.

Novel and potential future therapeutic options in Sjögren's syndrome

Sjögren's syndrome (SS) is a chronic autoimmune disease affecting the exocrine glands and can lead to various systemic symptoms impacting multiple organs. Despite its common occurrence, treatment options for SS have been largely limited, primarily focusing on alleviating symptoms rather than addressing the underlying autoimmune causes. A shift towards personalized medicine leads to the development of new therapeutic strategies aimed at targeting specific molecular pathways implicated in SS. Innovations in biologics are paving the way for inhibiting particular cytokines or cell surface molecules directly involved in the autoimmune mechanism. Furthermore, advancements in regenerative medicine, including the promising field of stem cell therapy, offer the potential for restoring or replacing the impaired salivary and lacrimal glands, providing hope for a more permanent resolution to this condition. This review encompasses cutting-edge treatment strategies for SS, spanning clinical and preclinical drugs to the latest treatment technology. Such advancements promise to drive targeted therapy development and inspire innovative ideas for treatment paradigms in SS.

Precision medicine in Sjögren's disease

Sjögren's disease is a clinically and pathophysiologically heterogeneous disease to which precision medicine, on the basis of clinical and biological heterogeneity, has been not always applicable. In patients with Sjögren's disease, the relationship between dysregulated biological pathways and symptoms such as fatigue and pain or clinical manifestations is often difficult to establish. This clinical and biological dissociation also poses challenges when defining appropriate clinical endpoints for clinical trials. In the last few years, however, research efforts have been focused on gaining a better understanding of the considerable heterogeneity of Sjögren's disease by developing stratification models aimed at clustering patients with this condition into homogenous subgroups characterised by distinctive molecular signatures, biomarkers, clinical features, and outcomes. In this Review, we discuss current evidence regarding clinical, laboratory, histological, and biomolecular stratification in Sjögren's disease and examine how available stratification data can guide precision medicine and inform the design of future clinical trials.

Safety and efficacy of subcutaneous iscalimab (CFZ533) in two distinct populations of patients with Sjögren's disease (TWINSS): week 24 results of a randomised, double-blind, placebo-controlled, phase 2b dose-ranging study

BACKGROUND

Sjögren's disease is a chronic autoimmune disease with an unmet need for targeted therapies. The aim of the TWINSS study is to evaluate the safety and efficacy of iscalimab, a monoclonal antibody against CD40, in patients with active Sjögren's disease.

METHODS

This randomised, double-blind, placebo-controlled, phase 2b study, conducted at 71 sites in 23 countries, enrolled patients aged 18 years or older fulfilling the American College of Rheumatology/European Alliance of Associations for Rheumatology (EULAR) 2016 criteria. In the dose-ranging cohort 1, patients with a EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score of 5 or higher and a EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) score of 5 or higher were randomly assigned (1:1:1:1) to subcutaneous iscalimab 150 mg, 300 mg, 600 mg, or placebo. In the proof-of-concept cohort 2, patients with an ESSDAI score of less than 5, ESSPRI (dryness or fatigue) score of 5 or higher, and Impact of Dry Eye on Everyday Life score of 30 or higher were randomly assigned (1:1) to iscalimab 600 mg or placebo. The sponsor, investigator, site personnel, and patients were masked to the treatment assignment. The primary objectives were to demonstrate a dose-response relationship of iscalimab based on the change in ESSDAI from baseline to week 24 in cohort 1 by Multiple Comparison Procedure-Modelling (MCP-Mod), and to assess the effect of iscalimab 600 mg on ESSPRI at week 24 in cohort 2. All the efficacy analyses included all patients who were randomly assigned, and safety analysis included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov (NCT03905525), and is complete.

FINDINGS

Between Oct 1, 2019, and Feb 28, 2022, 460 patients were screened; 173 patients were assigned to cohort 1 (44 to iscalimab 150 mg, 43 to 300 mg, 43 to 600 mg, and 43 to placebo) and 100 to cohort 2 (50 to each group). In cohort 1, the MCP step showed a significant dose-response relationship for placebo-adjusted ESSDAI change from baseline in one of four models (Linlog model, one-sided p=0·0041). ESSDAI decreased from baseline to week 24 with all three doses of iscalimab; 150 mg and 600 mg doses showed statistically significant improvement (placebo-adjusted least squares [LS] mean difference -3·0 [95% CI -4·9 to -1·1]; p=0·0025 for 150 mg and -2·9 [-4·9 to -1·0]; p=0·0037 for 600 mg). In cohort 2, ESSPRI showed a trend towards improvement with iscalimab 600 mg (placebo-adjusted LS mean change from baseline -0·57 points [95% CI -1·30 to 0·15]; p=0·12). Serious adverse events were reported in nine patients in cohort 1 (one [2%] of 43 in the placebo group, one [2%] of 44 in the iscalimab 150 mg group, three [7%] of 42 in the 300 mg group, four [9%] of 44 in the 600 mg group) and four patients in cohort 2 (two [4%] of 50 in each group). No deaths occurred over the 24-week period.

INTERPRETATION

The study met the primary objective of demonstrating a significant dose-response relationship with iscalimab in terms of disease activity at week 24. Iscalimab was well tolerated and showed initial clinical benefit over placebo in two distinct populations of patients with Sjögren's disease, to be confirmed in larger trials.

FUNDING

Novartis Pharma.

Update on the pathophysiology and treatment of primary Sjögren syndrome

Sjögren syndrome or Sjögren disease is a chronic form of autoimmune epithelitis characterized by lymphocytic infiltration of the exocrine glands, particularly the salivary and lacrimal glands, leading to progressive glandular dysfunction and subsequent xerostomia and xerophthalmia. Other common manifestations include pain and fatigue, various systemic manifestations and non-Hodgkin's lymphoma. Sjögren syndrome is therefore a complex and disabling disease associated with a reduced quality of life and with considerable long-term damage. Most of the available treatments are merely symptomatic with limited efficacy in both preventing glandular damage and suppressing systemic disease activity. In the past 10 years, great progress has been made in understanding the pathophysiology of Sjögren syndrome, opening new avenues towards a more targeted and individualized therapeutic approach to the disease. Indeed, several randomized controlled trials have just been completed or are poised to commence evaluating the effectiveness of novel drugs targeting both innate and adaptive immune pathways, including pro-inflammatory cytokines, the type I interferon system, B cell activation, B cell and T cell co-stimulation pathway, and ectopic germinal centre formation. Novel clinical trials are also ongoing exploring various targeted approaches (that is, IgG recycling inhibition, nuclease therapy and CAR-T cell therapy) for Sjögren syndrome.

KLRB1 defines an activated phenotype of CD4+ T cells and shows significant upregulation in patients with primary Sjögren's syndrome

OBJECTIVE

This study aimed to investigate the role of KLRB1 (CD161) in human CD4+ T cells and elucidate its significance in primary Sjögren's syndrome (pSS).

METHODS

Peripheral blood samples from 37 healthy controls and 44 pSS patients were collected. The publicly available single-cell RNA-Seq data from pSS patient PBMCs were utilized to analyse KLRB1 expression in T cells. KLRB1-expressing T lymphocyte subset proportions in pSS patients and healthy controls were determined by flow cytometry. CD25, Ki-67, cytokine secretion, and chemokine receptor expression in CD4+ KLRB1+ T cells were detected and compared with those in CD4+ KLRB1- T cells. Correlation analysis was conducted between KLRB1-related T-cell subsets and clinical indicators. ROC curves were generated to explore the diagnostic potential of KLRB1 for pSS.

RESULTS

KLRB1 was significantly upregulated following T-cell activation, and Ki-67 and CD25 expression was significantly greater in CD4+ KLRB1+ T cells than in CD4+ KLRB1- T cells. KLRB1+ CD4+ T cells exhibited greater IL-17A, IL-21, IL-22, and IFN-γ secretion upon stimulation, and there were significantly greater proportions of CCR5+, CCR2+, CX3CR1+, CCR6+, and CXCR3+ cells among CD4+ KLRB1+ T cells than among CD4+ KLRB1- T cells. Compared with that in HCs, KLRB1 expression in CD4+ T cells was markedly elevated in pSS patients and significantly correlated with clinical disease indicators.

CONCLUSION

KLRB1 is a characteristic molecule of the CD4+ T-cell activation phenotype. The increased expression of KLRB1 in the CD4+ T cells of pSS patients suggests its potential involvement in the pathogenesis of pSS and its utility as an auxiliary diagnostic marker for pSS.

The universal effects of low-dose interleukin-2 across 13 autoimmune diseases in a basket clinical trial

BACKGROUND

A Tregs insufficiency is central to autoimmune and inflammatory diseases pathophysiology and low dose interleukin-2 (IL-2LD) can specifically activate Tregs.

OBJECTIVE

To assess IL-2LD therapeutic potential and select diseases for further clinical development, we performed an open-label, phase 2a, disease-finding, "basket trial" involving patients with one of 13 different autoimmune diseases.

METHODS

81 patients treated with IL-2LD (1 million IU/day) for 5 days, followed by fortnightly injections. The first 48 patients received diluted Proleukin®, while the subsequent 33 received ready-to-use ILT-101®. The primary endpoint was the change in Tregs at day-8 compared to baseline. Key secondary endpoints included clinical efficacy assessments using the Clinical Global Impression (CGI) scale, disease-specific scores, and EuroQL-5D-5L.

RESULTS

Our study unveiled a universal and significant expansion and activation of Tregs, without concomitant Teffs activation, across all 13 autoimmune diseases. Both Proleukin® and ready-to-use ILT-101® demonstrated identical effects on Tregs. CGI scores reflecting activity, severity, and efficacy were significantly reduced in the overall patient population. Disease-specific clinical scores improved in five of the six disease cohorts with at least six patients, namely ankylosing spondylitis, systemic lupus erythematosus, Behçet's disease, Sjögren's syndrome, and systemic sclerosis. Urticaria was the only severe adverse event related to treatment.

CONCLUSION

IL-2LD was well-tolerated, exhibiting specific Treg activation and clinical improvements across the 13 autoimmune diseases.

CLINICAL IMPLICATION

Tregs stimulation by IL-2LD is a promising therapeutic strategy and IL-2LD holds considerable promise for integration into combinatorial therapeutic approaches.

Identification of outcome domains in primary Sjögren's disease: A scoping review by the OMERACT Sjögren disease working group

OBJECTIVES

Sjögren's disease (SjD) is a heterogenous disease with a wide range of manifestations, ranging from symptoms of dryness, fatigue, and pain, to systemic involvement. Considerable advances have been made to evaluate systemic activity or patient-reported outcomes, but most of the instruments were not able to assess all domains of this multifaceted disease. The aim of this scoping review was to generate domains that have been assessed in randomized controlled trials, as the first phase of the Outcome Measures in Rheumatology (OMERACT) process of core domain set development.

METHODS

We systematically searched Medline (Pubmed) and EMBASE between 2002 and March 2023 to identify all randomized controlled trials assessing relevant domains, using both a manual approach and an artificial intelligence software (BIBOT) that applies natural language processing to automatically identify relevant abstracts. Domains were mapped to core areas, as suggested by the OMERACT 2.1 Filter.

RESULTS

Among the 5,420 references, we included 60 randomized controlled trials, focusing either on overall disease manifestations (53%) or on a single organ/symptom: dry eyes (17%), xerostomia (15%), fatigue (12%), or pulmonary function (3%). The most frequently assessed domains were perceived dryness (52% for overall dryness), fatigue (57%), pain (52%), systemic disease activity (45%), lacrimal gland function (47%) and salivary function (55%), B-cell activation (60%), and health-related quality of life (40%).

CONCLUSION

Our scoping review highlighted the heterogeneity of SjD, in the study designs and domains. This will inform the OMERACT SjD working group to select the most appropriate core domains to be used in SjD clinical trials and to guide the future agenda for outcome measure research in SjD.

Molecular Engineering of Interleukin-2 for Enhanced Therapeutic Activity in Autoimmune Diseases

The interleukin-2 (IL-2) cytokine plays a crucial role in regulating immune responses and maintaining immune homeostasis. Its immunosuppressive effects have been harnessed therapeutically via administration of low cytokine doses. Low-dose IL-2 has shown promise in the treatment of various autoimmune and inflammatory diseases; however, the clinical use of IL-2 is complicated by its toxicity, its pleiotropic effects on both immunostimulatory and immunosuppressive cell subsets, and its short serum half-life, which collectively limit the therapeutic window. As a result, there remains a considerable need for IL-2-based autoimmune disease therapies that can selectively target regulatory T cells with minimal off-target binding to immune effector cells in order to prevent cytokine-mediated toxicities and optimize therapeutic efficacy. In this review, we discuss exciting advances in IL-2 engineering that are empowering the development of novel therapies to treat autoimmune conditions. We describe the structural mechanisms of IL-2 signaling, explore current applications of IL-2-based compounds as immunoregulatory interventions, and detail the progress and challenges associated with clinical adoption of IL-2 therapies. In particular, we focus on protein engineering approaches that have been employed to optimize the regulatory T-cell bias of IL-2, including structure-guided or computational design of cytokine mutants, conjugation to polyethylene glycol, and the development of IL-2 fusion proteins. We also consider future research directions for enhancing the translational potential of engineered IL-2-based therapies. Overall, this review highlights the immense potential to leverage the immunoregulatory properties of IL-2 for targeted treatment of autoimmune and inflammatory diseases.

New sights of low dose IL-2: Restoration of immune homeostasis for viral infection

Viral infection poses a significant threat to human health. In addition to the damage caused by viral replication, the immune response it triggers often leads to more serious adverse consequences. After the occurrence of viral infection, in addition to the adverse consequences of infection, chronic infections can also lead to virus-related autoimmune diseases and tumours. At the same time, the immune response triggered by viral infection is complex, and dysregulated immune response may lead to the occurrence of immune pathology and macrophage activation syndrome. In addition, it may cause secondary immune suppression, especially in patients with compromised immune system, which could lead to the occurrence of secondary infections by other pathogens. This can often result in more severe clinical outcomes. Therefore, regarding the treatment of viral infections, restoring the balance of the immune system is crucial in addition to specific antiviral medications. In recent years, scientists have made an interesting finding that low dose IL-2 (ld-IL-2) could potentially have a crucial function in regulating the immune system and reducing the chances of infection, especially viral infection. Ld-IL-2 exerts immune regulatory effects in different types of viral infections by modulating CD4+ T subsets, CD8+ T cells, natural killer cells, and so on. Our review summarised the role of IL-2 or IL-2 complexes in viral infections. Ld-IL-2 may be an effective strategy for enhancing host antiviral immunity and preventing infection from becoming chronic; additionally, the appropriate use of it can help prevent excessive inflammatory response after infection. In the long term, it may reduce the occurrence of infection-related autoimmune diseases and tumours by promoting the restoration of early immune homeostasis. Furthermore, we have also summarised the application of ld-IL-2 in the context of autoimmune diseases combined with viral infections; it may be a safe and effective strategy for restoring immune homeostasis without compromising the antiviral immune response. In conclusion, focusing on the role of ld-IL-2 in viral infections may provide a new perspective for regulating immune responses following viral infections and improving prognosis.

A humanized IL-2 mutein expands Tregs and prolongs transplant survival in preclinical models

Long-term organ transplant survival remains suboptimal, and life-long immunosuppression predisposes transplant recipients to an increased risk of infection, malignancy, and kidney toxicity. Promoting the regulatory arm of the immune system by expanding Tregs may allow immunosuppression minimization and improve long-term graft outcomes. While low-dose IL-2 treatment can expand Tregs, it has a short half-life and off-target expansion of NK and effector T cells, limiting its clinical applicability. Here, we designed a humanized mutein IL-2 with high Treg selectivity and a prolonged half-life due to the fusion of an Fc domain, which we termed mIL-2. We showed selective and sustainable Treg expansion by mIL-2 in 2 murine models of skin transplantation. This expansion led to donor-specific tolerance through robust increases in polyclonal and antigen-specific Tregs, along with enhanced Treg-suppressive function. We also showed that Treg expansion by mIL-2 could overcome the failure of calcineurin inhibitors or costimulation blockade to prolong the survival of major-mismatched skin grafts. Validating its translational potential, mIL-2 induced a selective and sustainable in vivo Treg expansion in cynomolgus monkeys and showed selectivity for human Tregs in vitro and in a humanized mouse model. This work demonstrated that mIL-2 can enhance immune regulation and promote long-term allograft survival, potentially minimizing immunosuppression.

The effects of low-dose IL-2 on Th17/Treg cell imbalance in primary biliary cholangitis mouse models

BACKGROUND/AIMS

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease. The imbalance of Th17/Treg cells has been reported in PBC patients. Low-dose IL-2 can alleviate disease severity through modulating CD4 + T cell subsets in patients with autoimmune diseases. Hence, the present study aimed to examine the effects and mechanism of low-dose IL-2 in PBC mouse models.

METHODS

PBC models were induced in female C57BL/6 mice by two immunizations with 2OA-BSA at two-week intervals, and poly I: C every three days. PBC mouse models were divided into the IL-2 treated and untreated groups and low-dose IL-2 was injected at three different time points. Th17 and Tregs were analyzed by flow cytometry, and the related cytokines were analyzed by ELISA. Liver histopathology was examined by H&E and immunohistochemical staining.

RESULTS

Twelve weeks after modeling, the serum AMA was positive and the ALP was significantly increased in PBC mouse models (P<0.05). The pathology showed lymphocyte infiltration in the portal area, damage, and reactive proliferation of the small bile duct (P<0.05). The flow cytometric showed the imbalance of Th17/Treg cells in the liver of PBC mouse models, with decreased Treg cells, increased Th17 cells, and Th17/Treg ratio (P < 0.05). After the low-dose IL-2 intervention, biochemical index and liver pathologies showed improvement at 12 weeks. Besides, the imbalance of Th17 and Treg cells recovered. Public database mining showed that Th17 cell differentiation may contribute to poor response in PBC patients.

CONCLUSION

Low-dose IL-2 can significantly improve liver biochemistry and pathology by reversing the imbalance of Th17 and Treg cells, suggesting that it may be a potential therapeutic target for PBC.

Efficacy and safety of remibrutinib, a selective potent oral BTK inhibitor, in Sjögren's syndrome: results from a randomised, double-blind, placebo-controlled phase 2 trial

OBJECTIVES

To evaluate the safety and efficacy of remibrutinib in patients with moderate-to-severe Sjögren's syndrome (SjS) in a phase 2 randomised, double-blind trial (NCT04035668; LOUiSSE (LOU064 in Sjögren's Syndrome) study).

METHODS

Eligible patients fulfilling 2016 American College of Rheumatology/European League Against Rheumatism (EULAR) criteria for SjS, positive for anti-Ro/Sjögren's syndrome-related antigen A antibodies, with moderate-to-severe disease activity (EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) (based on weighted score) ≥ 5, EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) ≥ 5) received remibrutinib (100 mg) either one or two times a day, or placebo for the 24-week study treatment period. The primary endpoint was change from baseline in ESSDAI at week 24. Key secondary endpoints included change from baseline in ESSDAI over time, change from baseline in ESSPRI over time and safety of remibrutinib in SjS. Key exploratory endpoints included changes to the salivary flow rate, soluble biomarkers, blood transcriptomic and serum proteomic profiles.

RESULTS

Remibrutinib significantly improved ESSDAI score in patients with SjS over 24 weeks compared with placebo (ΔESSDAI -2.86, p=0.003). No treatment effect was observed in ESSPRI score (ΔESSPRI 0.17, p=0.663). There was a trend towards improvement of unstimulated salivary flow with remibrutinib compared with placebo over 24 weeks. Remibrutinib had a favourable safety profile in patients with SjS over 24 weeks. Remibrutinib induced significant changes in gene expression in blood, and serum protein abundance compared with placebo.

CONCLUSIONS

These data show preliminary efficacy and favourable safety of remibrutinib in a phase 2 trial for SjS.

Manifestations and management of Sjögren's disease

Sjögren's disease is a heterogeneous autoimmune disorder that may be associated with systemic manifestations such as pulmonary or articular involvement. Systemic complications have prognostic implications and need to be identified and managed in a timely manner. Treatment should be tailored to the type and severity of organ involvement, ideally based on multidisciplinary evaluation.

New investigational drugs to treat Sjogren's syndrome: lessons learnt from immunology

INTRODUCTION

Sjögren's syndrome is a heterogeneous autoimmune condition that impairs quality of life because of dryness, fatigue, pain, and systemic involvements. Current treatment largely depends on empirical evidence, with no effective therapy approved. Clinical trials on targeted drugs often fail to report efficacy due to common factors.

AREAS COVERED

This review summarizes the pathogenesis and what caused the failure of new investigational drugs in clinical trials, highlighting solutions for more effective investigations, with greater consistency between research outcomes, clinical use, and patient needs.

EXPERT OPINION

Unlinked pathobiology with symptoms resulted in misidentified targets and disappointing trials. Useful stratification tools are necessary for the heterogeneous SS patients. Composite endpoints or improvements in ESSDAI scores are needed, considering the high placebo response, and the unbalance between symptom burden and disease activity. Compared to classic biologics, targeted cell therapy will be a more promising field of investigation in the coming years.

Evaluation and management of dry mouth and its complications in rheumatology practice

INTRODUCTION

The symptom of dry mouth has multiple potential etiologies and can be a diagnostic clue to the presence of common systemic diseases encountered in rheumatology practice. The presence of decreased saliva flow (i.e. salivary hypofunction) defines a subset of dry mouth patients in whom there may be reversible drug effects, an iatrogenic insult such as head and neck irradiation, or a disease that directly involves the salivary glands (e.g. Sjögren's disease). The assessment of salivary hypofunction includes sialometry, salivary gland imaging, salivary gland biopsy, and an assessment for relevant systemic diseases. Optimal management of dry mouth requires accurate definition of its cause, followed by general measures that serve to alleviate its symptoms and prevent its complications.

AREAS COVERED

Through a literature search on xerostomia and salivary hypofunction, we provide an overview of the causes of dry mouth, highlight the potential impact of salivary hypofunction on oral and systemic health, detail routine evaluation methods and treatment strategies, and emphasize the importance of collaboration with oral health care providers.

EXPERT OPINION

Our Expert Opinion is provided on unmet needs in the management of dry mouth and relevant research progress in the field.

Mechanisms of Stem Cells and Their Secreted Exosomes in the Treatment of Autoimmune Diseases

Stem cells play a therapeutic role in many diseases by virtue of their strong self-renewal and differentiation abilities, especially in the treatment of autoimmune diseases. At present, the mechanism of the stem cell treatment of autoimmune diseases mainly relies on their immune regulation ability, regulating the number and function of auxiliary cells, anti-inflammatory factors and proinflammatory factors in patients to reduce inflammation. On the other hand, the stem cell- derived secretory body has weak immunogenicity and low molecular weight, can target the site of injury, and can extend the length of its active time in the patient after combining it with the composite material. Therefore, the role of secretory bodies in the stem cell treatment of autoimmune diseases is increasingly important.

Emerging treatment for Sjögren's disease: a review of recent phase II and III trials

INTRODUCTION

Sjögren's Disease, SjD, is a systemic autoimmune disorder characterized by reduced function of the salivary and lacrimal glands. Patients suffer from dryness, fatigue, and pain and may present with or without extra-glandular organ involvement. Symptoms limit SjD patients' quality of life and are the most difficult to improve with therapy. SjD patients are heterogeneous and clustering them into biologically similar subgroups might improve the efficacy of therapies. The need for therapies that address both the symptoms and extra glandular organ involvement of SjD presents an unmet opportunity that has recently attracted a growing interest in the pharmaceutical industry.

AREAS COVERED

The goal of this report is to review recent phase II/III studies in SjD. To accomplish our goal, we performed a literature search for phase II/III studies and abstracts recently presented at conferences.

EXPERT OPINION

This review allows updates the reader on the multitude of recent phase II/III clinical trials. We speculate on how subtypes of SjD will drive future therapeutic targeting and inform pathogenesis.

Visual analysis of autoimmune dry eye studies based on bibliometrics

BACKGROUND

Dry eye is a chronic ocular surface disease caused by the instability of tear film or the imbalance of the ocular surface microenvironment which can lead to a diverse range of ocular discomfort symptoms. At present, the relevant mechanism of autoimmunity and treatment of dry eye is still unclear. Due to the proliferation of research papers in this field, visual analysis of existing papers can provide reference for future research.

METHODS

The academic papers of Web of Science were searched with the topics of "autoimmunity" and "dry eye," and the countries, institutions and keywords of the literatures selected in this domain were visualized by Citespace and Vosviewer software.

RESULTS

A total of 787 valid international papers were detected, and the publication count exhibited a consistent upward trend year by year. Within this field, the US has produced the highest number of papers (363), with Baylor College of Medicine being the most prolific institution (28 publications). High-producing authors in this field include Artemis P. Simopoulos and Stephen C. Pflugfelder.

CONCLUSION

International research in this field has focused on the pathogenesis, symptoms, and treatment of dry eye. It is predicted that the future international research hotspots will be the pathophysiology of autoimmune dry eye disease, data analysis of artificial intelligence-related diseases, and research on improving patients' quality of life.

Increased serum soluble interleukin-2 receptor levels in dermatomyositis are associated with Th17/Treg immune imbalance

Dermatomyositis (DM) represents a multifaceted chronic inflammatory myopathy, primarily manifesting as progressive deterioration of muscular and cutaneous tissues. Despite an incomplete comprehension of DM's etiology and pathogenesis, current evidence implicates the involvement of T lymphocyte infiltration, extensive cytokine release, myositis-specific antibodies, and myositis-associated antibodies in disease development. Serum soluble interleukin-2 receptor (sIL-2R) frequently serves as a marker for T cell activation; however, its role remains elusive. Consequently, this investigation sought to elucidate the association between sIL-2R levels, peripheral blood lymphocyte subset counts, and related cytokines in DM patients, with the aim of uncovering the intricate mechanisms underlying DM and establishing a theoretical foundation for the implementation of precise, targeted, individualized immunomodulatory therapy. In this study, a cohort of 60 dermatomyositis (DM) patients, comprising 32 with inactive DM and 28 with active DM, was enrolled and stratified into inactive and active groups based on the Myositis Disease Activity Visual Analogue Scale (MYOACT). Flow cytometry was employed to quantify the absolute counts of peripheral lymphocyte subsets and CD4+T cell subsets in each group, while a flow cytometry bead array was utilized to measure serum cytokine levels. In a comparative analysis between healthy individuals and patients diagnosed with DM, we observed a marked elevation in serum sIL-2R concentrations (P < 0.001) and T-helper 17 cell/regulatory T cell (Th17/Treg) ratios (P < 0.01) within the latter group. A positive correlation was identified between serum sIL-2R levels and various parameters, including ESR, CRP, VAS, AST, CKMB, LDH, HBDH, PT, APTT, DDi, IL-6, IL-10, and IFN-γlevels (P < 0.05). In contrast, serum sIL-2R levels demonstrated a negative correlation with LY, HGB, ALB, Th17 cell populations, and Th17/Treg cell ratios (P < 0.05). Employing multivariate logistic regression, we identified serum sIL-2R concentrations as an independent risk factor for both disease activity and hepatic involvement in DM patients. Moreover, receiver operating characteristic (ROC) curve analyses revealed that serum sIL-2R levels significantly contributed to the differentiation of disease activity and the detection of liver involvement in DM patients, with areas under the ROC curve (AUC) of 0.757 (95% CI 0.630-0.884, P = 0.001) and 0.826 (95% CI 0.717-0.935, P < 0.001), respectively. This study highlights the potential utility of serum sIL-2R levels as a valuable biomarker for assessing disease activity and liver involvement in dermatomyositis. Elevated serum concentrations of sIL-2R were observed in patients with DM, exhibiting significant associations with Th17 cell populations and Th17/ Treg ratios. These findings indicate that sIL-2R may be implicated in the immunopathogenesis of DM, thereby warranting further investigation to elucidate its role in the disease process.

Inflammation across tissues: can shared cell biology help design smarter trials?

Immune-mediated inflammatory diseases (IMIDs) are responsible for substantial global disease burden and associated health-care costs. Traditional models of research and service delivery silo their management within organ-based medical disciplines. Very often patients with disease in one organ have comorbid involvement in another, suggesting shared pathogenic pathways. Moreover, different IMIDs are often treated with the same drugs (including glucocorticoids, immunoregulators and biologics). Unlocking the cellular basis of these diseases remains a major challenge, leading us to ask why, if these diseases have so much in common, they are not investigated in a common manner. A tissue-based, cellular understanding of inflammation might pave the way for cross-disease, cross-discipline basket trials (testing one drug across two or more diseases) to reduce the risk of failure of early-phase drug development in IMIDs. This new approach will enable rapid assessment of the efficacy of new therapeutic agents in cross-disease translational research in humans.

Pervasive Sharing of Causal Genetic Risk Factors Contributes to Clinical and Molecular Overlap between Sjögren's Disease and Systemic Lupus Erythematosus

SjD (Sjögren's Disease) and SLE (Systemic Lupus Erythematosus) are similar diseases. There is extensive overlap between the two in terms of both clinical features and pathobiologic mechanisms. Shared genetic risk is a potential explanation of this overlap. In this study, we evaluated whether these diseases share causal genetic risk factors. We compared the causal genetic risk for SLE and SjD using three complementary approaches. First, we examined the published GWAS results for these two diseases by analyzing the predicted causal gene protein-protein interaction networks of both diseases. Since this method does not account for overlapping risk intervals, we examined whether such intervals also overlap. Third, we used two-sample Mendelian randomization (two sample MR) using GWAS summary statistics to determine whether risk variants for SLE are causal for SjD and vice versa. We found that both the putative causal genes and the genomic risk intervals for SLE and SjD overlap 28- and 130-times more than expected by chance (p < 1.1 × 10-24 and p < 1.1 × 10-41, respectively). Further, two sample MR analysis confirmed that alone or in aggregate, SLE is likely causal for SjD and vice versa. [SjD variants predicting SLE: OR = 2.56; 95% CI (1.98-3.30); p < 1.4 × 10-13, inverse-variance weighted; SLE variants predicting SjD: OR = 1.36; 95% CI (1.26-1.47); p < 1.6 × 10-11, inverse-variance weighted]. Notably, some variants have disparate impact in terms of effect size across disease states. Overlapping causal genetic risk factors were found for both diseases using complementary approaches. These observations support the hypothesis that shared genetic factors drive the clinical and pathobiologic overlap between these diseases. Our study has implications for both differential diagnosis and future genetic studies of these two conditions.

Autoimmune uveitis in Behçet's disease and Vogt-Koyanagi-Harada disease differ in tissue immune infiltration and T cell clonality

Objectives

Non-infectious uveitis is often secondary to systemic autoimmune diseases, with Behçet's disease (BD) and Vogt-Koyanagi-Harada disease (VKHD) as the two most common causes. Uveitis in BD and VKHD can show similar clinical manifestations, but the underlying immunopathogenesis remains unclear.

Methods

To understand immune landscapes in inflammatory eye tissues, we performed single-cell RNA paired with T cell receptor (TCR) sequencing of immune cell infiltrates in aqueous humour from six patients with BD (N = 3) and VKHD (N = 3) uveitis patients.

Results

Although T cells strongly infiltrated in both types of autoimmune uveitis, myeloid cells only significantly presented in BD uveitis but not in VKHD uveitis. Conversely, VKHD uveitis but not BD uveitis showed an overwhelming dominance by CD4+ T cells (> 80%) within the T cell population due to expansion of CD4+ T cell clusters with effector memory (Tem) phenotypes. Correspondingly, VKHD uveitis demonstrated a selective expansion of CD4+ T cell clones which were enriched in pro-inflammatory Granzyme H+ CD4+ Tem cluster and showed TCR and Th1 pathway activation. In contrast, BD uveitis showed a preferential expansion of CD8+ T cell clones in pro-inflammatory Granzyme H+ CD8+ Tem cluster, and pathway activation for cytoskeleton remodelling, cellular adhesion and cytotoxicity.

Conclusion

Single-cell analyses of ocular tissues reveal distinct landscapes of immune cell infiltration and T-cell clonal expansions between VKHD and BD uveitis. Preferential involvements of pro-inflammatory CD4+ Th1 cells in VKHD and cytotoxic CD8+ T cells in BD suggest a difference in disease immunopathogenesis and can guide precision disease management.

Regulatory T cells: a new therapeutic link for Sjögren syndrome?

Great advancements have been made in understanding the pathogenesis of SS, but there remain unmet needs for effective and targeted treatments. Glandular and extraglandular dysfunction in SS is associated with autoimmune lymphocytic infiltration that invades the epithelial structures of affected organs. Regulatory T (Treg) cells are a subset of CD4+ T lymphocytes that maintain self-tolerance during physiological conditions. Besides inhibiting excessive inflammation and autoimmune response by targeting various immune cell subsets and tissues, Treg cells have also been shown to promote tissue repair and regeneration in pathogenic milieus. The changes of quantity and function of Treg cells in various autoimmune and chronic inflammatory disorders have been reported, owing to their effects on immune regulation. Here we summarize the recent findings from murine models and clinical data about the dysfunction of Treg cells in SS pathogenesis and discuss the therapeutic strategies of direct or indirect targeting of Treg cells in SS. Understanding the current knowledge of Treg cells in the development of SS will be important to elucidate disease pathogenesis and may guide research for successful therapeutic intervention in this disease.

Effect of adipose tissue-derived stem cells therapy on clinical response in patients with primary Sjogren's syndrome

The purpose of this trial was to clinically assess the effect and safety of Adipose Tissue-derived Stem Cells (ADSCs) treatment on primary Sjogren's Syndrome (pSS). In this 6-month randomized, triple-blind, placebo-controlled clinical trial, pSS patients were randomly assigned to two groups. After demographic characteristics and clinical examination were achieved, local injection of ADSCs into bilateral glands was performed with patients in ADSCs group (n = 35) and placebo solution was used for another group (n = 39) at three time points. Patients were followed up at 1-, 3- and 6-month. At each visit, studies of clinical and laboratory outcomes, as well as subjective symptoms, were conducted. A total of 74 subjects who met the including criteria were allocated in two groups and eventually 64 subjects (86.5%) completed the treatments and the follow-up assessments. Secretion of salivary and lachrymal glands were significantly improved in 3-month (P < 0.05). A great improvement of European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) was found after ADSCs treatment with intergroup comparison from baseline to follow-up (P < 0.05). There is also a significant difference of European Alliance of Associations for Rheumatology SS Patient Reported Index (ESSPRI) between the two groups in the follow-up (P < 0.05). A significant abatement of IgG, IgM, C3, C4 and ESR between two groups was observed in part of follow-up time points (P < 0.05). The ADSCs therapy can provide relief of oral and eye's dryness in our trial in a short time and has potential improvement of subjective and systemic syndromes of pSS.

Role of IL-2/IL-2 receptor in pathogenesis of autoimmune disorders: Genetic and therapeutic aspects

Interleukin-2 (IL-2) is an important cytokine that plays a key role in the immune response. The IL-2 receptor (IL-2R) is composed of three subunits, alpha, beta, and gamma, with the alpha subunit having the highest affinity for IL-2. Several studies reported that immune dysregulation of IL-2 may cause tissue injury as well as damage leading to the pathogenesis of various autoimmune diseases such as acute necrotizing vasculitis in systemic lupus erythematosus (SLE), inflammatory synovitis in rheumatoid arthritis (RA), salivary and lacrimal gland dys-function in Sjogren syndrome (SS), obliterative vasculopathy fibrosis in systemic sclerosis (SSc), and inflammatory demyelination in multiple sclerosis (MS). The aim of this review paper was to examine the role of IL-2/IL-2R in various autoimmune disorders, taking into account recent advancements and discoveries, gaps in the current literature, ongoing debates, and potential avenues for future research. The focus of this review is on systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, sjogren syndrome, and multiple sclerosis, which are all linked to the malfunctioning of IL-2/IL-2R. In genetic studies, gene polymorphisms of IL-2 such as IL-2 330/T, IL-2 330/G, and rs2069763 are involved in increasing the risk of SLE. Furthermore, genetic associations of IL-2/IL-2R such as rs791588, rs2281089, rs2104286, rs11594656, and rs35285258 are significantly associated with RA susceptibility. The IL-2 polymorphism including rs2069762A, rs6822844T, rs6835457G, and rs907715T are significant connections with systemic sclerosis. In addition, rs2104286 (IL-2), rs11594656 (IL-2RA), rs35285258 (IL-2RB) gene polymorphism significant increases the risk of multiple sclerosis. In therapeutic approaches, low-dose IL-2 therapy could regulate Tfr and Tfh cells, resulting in a reduction in disease activity in the SLE patients. In addition, elevated sIL-2R levels in the peripheral blood of SLE patients could be linked to an immunoregulatory imbalance, which may contribute to the onset and progression of SLE. Consequently, sIL-2R could potentially be a target for future SLE therapy. Moreover, Low dose-IL2 was well-tolerated, and low levels of Treg and high levels of IL-21 were associated with positive responses to Ld-IL2 suggested to be a safe and effective treatment for RA. Additionally, low-dose IL-2 treatment improves the exocrine glands' ability to secrete saliva in SS-affected mice. Whereas, Basiliximab targets the alpha chain of the IL-2 receptor suggested as a potential treatment for SSc. Also, pre-and post-treatment with Tregs, MDSCs, and IL-2 may have the potential to prevent EAE induction in patients with MS. It is suggested that further studies should be conducted on IL-2 polymorphism in Sjogren syndrome.

The Spectrum of Extraglandular Manifestations in Primary Sjögren's Syndrome

Extraglandular manifestations (EGMs) in primary Sjogren's syndrome (pSS) represent the clinical expression of the systemic involvement in this disease. EGMs are characterized by a wide heterogeneity; virtually any organ or system can be affected, with various degrees of dysfunction. The existing gaps of knowledge in this complex domain of extraglandular extension in pSS need to be overcome in order to increase the diagnostic accuracy of EGMs in pSS. The timely identification of EGMs, as early as from subclinical stages, can be facilitated using highly specific biomarkers, thus preventing decompensated disease and severe complications. To date, there is no general consensus on the diagnostic criteria for the wide range of extraglandular involvement in pSS, which associates important underdiagnosing of EGMs, subsequent undertreatment and progression to severe organ dysfunction in these patients. This review article presents the most recent basic and clinical science research conducted to investigate pathogenic mechanisms leading to EGMs in pSS patients. In addition, it presents the current diagnostic and treatment recommendations and the trends for future therapeutic strategies based on personalized treatment, as well as the latest research in the field of diagnostic and prognostic biomarkers for extraglandular involvement in pSS.

Mechanism-based target therapy in primary biliary cholangitis: opportunities before liver cirrhosis?

Primary biliary cholangitis (PBC) is an immune-mediated liver disease characterized by cholestasis, biliary injuries, liver fibrosis, and chronic non-suppurative cholangitis. The pathogenesis of PBC is multifactorial and involves immune dysregulation, abnormal bile metabolism, and progressive fibrosis, ultimately leading to cirrhosis and liver failure. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are currently used as first- and second-line treatments, respectively. However, many patients do not respond adequately to UDCA, and the long-term effects of these drugs are limited. Recent research has advanced our understanding the mechanisms of pathogenesis in PBC and greatly facilitated development of novel drugs to target mechanistic checkpoints. Animal studies and clinical trials of pipeline drugs have yielded promising results in slowing disease progression. Targeting immune mediated pathogenesis and anti-inflammatory therapies are focused on the early stage, while anti-cholestatic and anti-fibrotic therapies are emphasized in the late stage of disease, which is characterized by fibrosis and cirrhosis development. Nonetheless, it is worth noting that currently, there exists a dearth of therapeutic options that can effectively impede the progression of the disease to its terminal stages. Hence, there is an urgent need for further research aimed at investigating the underlying pathophysiology mechanisms with potential therapeutic effects. This review highlights our current knowledge of the underlying immunological and cellular mechanisms of pathogenesis in PBC. Further, we also address current mechanism-based target therapies for PBC and potential therapeutic strategies to improve the efficacy of existing treatments.

Immune-mediated lung diseases: A narrative review

The role of immunity in the pathogenesis of various pulmonary diseases, particularly interstitial lung diseases (ILDs), is being increasingly appreciated as mechanistic discoveries advance our knowledge in the field. Immune-mediated lung diseases demonstrate clinical and immunological heterogeneity and can be etiologically categorized into connective tissue disease (CTD)-associated, exposure-related, idiopathic, and other miscellaneous lung diseases including sarcoidosis, and post-lung transplant ILD. The immunopathogenesis of many of these diseases remains poorly defined and possibly involves either immune dysregulation, abnormal healing, chronic inflammation, or a combination of these, often in a background of genetic susceptibility. The heterogeneity and complex immunopathogenesis of ILDs complicate management, and thus a collaborative treatment team should work toward an individualized approach to address the unique needs of each patient. Current management of immune-mediated lung diseases is challenging; the choice of therapy is etiology-driven and includes corticosteroids, immunomodulatory drugs such as methotrexate, cyclophosphamide and mycophenolate mofetil, rituximab, or other measures such as discontinuation or avoidance of the inciting agent in exposure-related ILDs. Antifibrotic therapy is approved for some of the ILDs (e.g., idiopathic pulmonary fibrosis) and is being investigated for many others and has shown promising preliminary results. A dire need for advances in the management of immune-mediated lung disease persists in the absence of standardized management guidelines.

Regulatory Mechanisms and Reversal of CD8+T Cell Exhaustion: A Literature Review

CD8+T cell exhaustion is a state of T cell dysfunction during chronic infection and tumor progression. Exhausted CD8+T cells are characterized by low effector function, high expression of inhibitory receptors, unique metabolic patterns, and altered transcriptional profiles. Recently, advances in understanding and interfering with the regulatory mechanisms associated with T cell exhaustion in tumor immunotherapy have brought greater attention to the field. Therefore, we emphasize the typical features and related mechanisms of CD8+T cell exhaustion and particularly the potential for its reversal, which has clinical implications for immunotherapy.

Low-dose interleukin-2 treatment increases the proportion of regulatory T cells in patients with rheumatic diseases: A meta-analysis

BACKGROUND

It is now accepted that immune tolerance disorders caused by inadequate Treg cell function or number are important factors in the development and progression of rheumatic diseases. There is increasing evidence that ld IL-2 treatment increases the proportion of Treg cells in patients' peripheral blood, but this conclusion is still controversial. Here, we performed a meta-analysis of reports documenting the proportion of Treg cells and the rate of adverse events in patients with rheumatic disease before and after the administration of ld IL-2 to better understand its effect and safety on Treg cells in the field of rheumatic diseases.

METHODS

We systematically searched PubMed, Embase, Scopus, Cochrane Library, and Web of science databases up to 15th November 2022 and identified studies that reported the proportion of peripheral blood Treg cells before and after ld IL-2 treatment in patients with rheumatic disease. Random-effects model was used to perform a meta-analysis of Treg cell proportions before and after ld IL-2 administration, and a meta-regression analysis was performed to explore heterogeneity. Inconsistency was evaluated using the I-squared index (I²), and publication bias was assessed by examining funnel plot asymmetry using the Egger tests.

RESULTS

Eighteen studies involving 1608 patients were included in the meta-analysis. The proportion of Treg cells in peripheral blood of these patients increased significantly after receiving ld IL-2 treatment [1.07 (95% CI 0.86,1.27), p < 0.001, I² = 67.3%]. Next, Meta-regression was performed for 5 variables including publish year, disease type, trail type and dosage and duration of the medication. The results suggest that these variables do not lead to high heterogeneity. (p = 0.698, 0.267, 0.502, 0.843, 0.560, respectively). And finally, statistical analysis showed no difference in adverse reactions between ld IL-2 group and control group in treatment [1.06 (95% CI 0.86,1.31), p = 0.586, I2 = 53.8%], which is unreliable because the data is so small.

CONCLUSIONS

Ld IL-2 does increase the proportion of peripheral blood Treg cells in patients with rheumatism, and single and cumulative doses must be considered when using ld IL-2. In addition, more studies on the safety of ld IL-2 are urgently needed.