Increased Levels of Soluble Programmed Death Ligand 1 Associate with Malignancy in Patients with Dermatomyositis

The effect of combining PD-1 agonist and low-dose Interleukin-2 on treating systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs. It is often called "immortal cancer" due to the difficulties in disease treatment. As the cornerstone of immune regulation, the programmed cell death protein 1 (PD-1) has been extensively studied in the context of chronic inflammation due to its ability of regulating immune response and immunosuppression. Recently, more and more studies on rheumatic immune related complications have also focused on PD-1 and proposed that the use of PD-1 agonist could inhibit the activation of lymphocytes and alleviate SLE disease activity. In this review, we summarized the role of PD-1 in SLE, implicating its potential application as a biomarker to predict SLE disease activity; we also proposed that the combination of PD-1 agonist and low-dose IL-2 may have better therapeutic efficacy, shining light on a new direction for developing specific treatment approaches.

Beyond Cancer: Regulation and Function of PD-L1 in Health and Immune-Related Diseases

Programmed Cell Death 1 Ligand 1 (PD-L1, CD274, B7-H1) is a transmembrane protein which is strongly involved in immune modulation, serving as checkpoint regulator. Interaction with its receptor, Programmed Cell Death Protein 1 (PD-1), induces an immune-suppressive signal, which modulates the activity of T cells and other effector cells. This mediates peripheral tolerance and contributes to tumor immune escape. PD-L1 became famous due to its deployment in cancer therapy, where blockage of PD-L1 with the help of therapeutic antagonistic antibodies achieved impressive clinical responses by reactivating effector cell functions against tumor cells. Therefore, in the past, the focus has been placed on PD-L1 expression and its function in various malignant cells, whereas its role in healthy tissue and diseases apart from cancer remained largely neglected. In this review, we summarize the function of PD-L1 in non-cancerous cells, outlining its discovery and origin, as well as its involvement in different cellular and immune-related processes. We provide an overview of transcriptional and translational regulation, and expression patterns of PD-L1 in different cells and organs, and illuminate the involvement of PD-L1 in different autoimmune diseases as well as in the context of transplantation and pregnancy.

Revisiting PD-1/PD-L pathway in T and B cell response: Beyond immunosuppression

The regulation of T cell response depends on co-inhibitory pathways that serve to control immune-mediated tissue damage and resolve inflammation by modulating the magnitude and duration of immune response. In this process, the axis of T-cell-expressed programmed death-1 (PD-1) and its ligands (PD-L1 and PD-L2) play a key role. While the PD-1/PD-L pathway has received considerable attention for its role in the maintenance of T cell exhaustion in cancer and chronic infection, the PD-1/PD-L pathway also plays diverse roles in regulating host immunity beyond T cell exhaustion. In this review, we will discuss emerging concepts in co-stimulatory functions of PD-1/PD-L pathway on T cell- and B cell response and explore the potential underlying mechanisms. In addition, based on the elevated expression of PD-1 and its ligands in local inflamed tissues, we further discussed the role of PD-1/PD-L pathway in autoimmune diseases.

Machine Learning Algorithms Identify Clinical Subtypes and Cancer in Anti-TIF1γ+ Myositis: A Longitudinal Study of 87 Patients

Background

Anti-TIF1γ antibodies are a class of myositis-specific antibodies (MSAs) and are closely associated with adult cancer-associated myositis (CAM). The heterogeneity in anti-TIF1γ+ myositis is poorly explored, and whether anti-TIF1γ+ patients will develop cancer or not is unknown at their first diagnosis. Here, we aimed to explore the subtypes of anti-TIF1γ+ myositis and construct machine learning classifiers to predict cancer in anti-TIF1γ+ patients based on clinical features.

Methods

A cohort of 87 anti-TIF1γ+ patients were enrolled and followed up in Xiangya Hospital from June 2017 to June 2021. Sankey diagrams indicating temporal relationships between anti-TIF1γ+ myositis and cancer were plotted. Elastic net and random forest were used to select and rank the most important variables. Multidimensional scaling (MDS) plot and hierarchical cluster analysis were performed to identify subtypes of anti-TIF1γ+ myositis. The clinical characteristics were compared among subtypes of anti-TIF1γ+ patients. Machine learning classifiers were constructed to predict cancer in anti-TIF1γ+ myositis, the accuracy of which was evaluated by receiver operating characteristic (ROC) curves.

Results

Forty-seven (54.0%) anti-TIF1γ+ patients had cancer, 78.7% of which were diagnosed within 0.5 years of the myositis diagnosis. Fourteen variables contributing most to distinguishing cancer and non-cancer were selected and used for the calculation of the similarities (proximities) of samples and the construction of machine learning classifiers. The top 10 were disease duration, percentage of lymphocytes (L%), percentage of neutrophils (N%), neutrophil-to-lymphocyte ratio (NLR), sex, C-reactive protein (CRP), shawl sign, arthritis/arthralgia, V-neck sign, and anti-PM-Scl75 antibodies. Anti-TIF1γ+ myositis patients can be clearly separated into three clinical subtypes, which correspond to patients with low, intermediate, and high cancer risk, respectively. Machine learning classifiers [random forest, support vector machines (SVM), extreme gradient boosting (XGBoost), elastic net, and decision tree] had good predictions for cancer in anti-TIF1γ+ myositis patients. In particular, the prediction accuracy of random forest was >90%, and decision tree highlighted disease duration, NLR, and CRP as critical clinical parameters for recognizing cancer patients.

Conclusion

Anti-TIF1γ+ myositis can be separated into three distinct subtypes with low, intermediate, and high risk of cancer. Machine learning classifiers constructed with clinical characteristics have favorable performance in predicting cancer in anti-TIF1γ+ myositis, which can help physicians in choosing appropriate cancer screening programs.

Update on Malignancy in Myositis—Well-Established Association with Unmet Needs

Idiopathic inflammatory myopathies are a group of rare connective tissue diseases with a well-documented association with malignancy. The mechanisms underlying the increased risk of neoplasms in the course of myositis are not fully understood. The Pubmed database has been thoroughly screened for articles concerning cancer-associated myositis (CAM). The article summarizes the current state of knowledge on the epidemiology and pathogenesis of CAM. Furthermore, it analyses potential risk and protective factors for developing CAM, with particular emphasis on the association with distinct serological profiles. The review summarizes recommendations proposed so far for the management of CAM and presents a novel scheme for cancer screening proposed by the authors. Moreover, promising areas requiring further research were indicated.

Considerations for immunotherapy in patients with cancer and comorbid immune dysfunction

Immune checkpoint inhibitors have been widely incorporated for cancer treatment in a variety of solid and hematologic malignancies. Multiple clinical trials have demonstrated the efficacy of PD-1/PD-L1 and CTLA-4 axis inhibition in the metastatic and adjuvant settings. Due to the risks of autoimmune toxicity with these agents, stringent inclusion/exclusion criteria were employed in those initial clinical trials. These criteria led to exclusion or underrepresentation of a variety of patient populations with underlying immune dysfunction. These populations included patients with preexisting autoimmune diseases, solid organ or bone marrow transplant recipients, patients with HIV or viral hepatitis infections, patients receiving concurrent chronic steroid therapy, as well as patients who were elderly, pregnant, or had poor performance status. Thus, established guidelines on the use of immune checkpoint inhibitors in these patients are lacking, and evidence to support efficacy or toxicity are overall limited to retrospective studies and case series. Fortunately, ongoing clinical trials are now including these patients and are shedding light on whether these underrepresented populations can also safely benefit from immune checkpoint inhibitor therapies. In this review, we summarize the most clinically relevant available data on the use of checkpoint inhibitors in immunocompromised patient groups with a primary focus on safety.

Reappraisal of the incidence, various types and risk factors of malignancies in patients with dermatomyositis and polymyositis in Taiwan

Our study aimed to investigate the incidence, risk factors and time to occurrence of malignancy in patients with dermatomyositis (DM) and polymyositis (PM). The electronic medical records of 1100 patients with DM and 1164 patients with PM were studied between January 2001 and May 2019. Malignancies after myositis were diagnosed in 61 (5.55%) patients with DM and 38 (3.26%) patients with PM. The cumulative incidence of malignancies in patients with DM were significantly higher than patients with PM (hazard ratio = 1.78, log-rank p = 0.004). Patients with DM had a greater risk of developing malignancy than those with PM at 40–59 years old (p = 0.01). Most malignancies occurred within 1 year after the initial diagnosis of DM (n = 35; 57.38%). Nasopharyngeal cancer (NPC) was the most common type of malignancy in patients with DM (22.95%), followed by lung, and breast cancers. In patients with PM, colorectal, lung and hepatic malignancies were the top three types of malignancy. The risk factors for malignancy included old age (≥ 45 years old) and low serum levels of creatine phosphokinase (CPK) for patients with DM and male sex and low serum levels of CPK for patients with PM. Low serum levels of CPK in patients with myositis with malignancy represented a low degree of muscle destruction/inflammation, which might be attributed to activation of the PD-L1 pathway by tumor cells, thus inducing T-cell dysfunction mediating immune responses in myofibers. A treatment and follow-up algorithm should explore the occurrence of malignancy in different tissues and organs and suggested annual follow-ups for at least 5.5 years to cover the 80% cumulative incidence of malignancy in patients with DM and PM.

Preexisting autoimmune disease and immune-related adverse events associated with anti-PD-1 cancer immunotherapy: a national case series from the Canadian Research Group of Rheumatology in Immuno-Oncology

BACKGROUND

Limited data are available on the safety and efficacy of immune checkpoint inhibitors (ICI) in patients with preexisting autoimmune diseases (PAD).

METHODS

Retrospective study of patients with PAD referred for rheumatologic evaluation prior to starting or during immunotherapy between January 2013 and July 2019 from 10 academic sites across Canada. Data were extracted by chart review using a standardized form.

RESULTS

Twenty-seven patients with PAD on ICI therapy were identified. The most common PADs were rheumatoid arthritis (30%), psoriasis/psoriatic arthritis (30%), inflammatory bowel disease (IBD, 15%) and axial spondyloarthritis (11%), and the most frequently observed cancers were lung cancer and melanoma. All patients received anti-PD-1 therapies, and 2 received additional sequential anti-CTLA-4 therapy. PAD exacerbations occurred in 52% over a median (IQR) follow-up of 11.0 (6.0-17.5) months, with 14% being severe, 57% requiring corticosteroids, 50% requiring immunosuppression and 14% requiring ICI discontinuation. Flares were generally more frequent and severe in patients who previously required more intensive immunosuppression (i.e., biologics). Flares occurred despite background immunosuppression at the time of ICI initiation. In patients with preexisting psoriasis, IBD and axial spondyloarthritis, rheumatic immune-related adverse events (irAEs), mostly polyarthritis and tenosynovitis, were frequently observed. Tumor progression was not associated with exposure to immunosuppressive drugs before or after ICI initiation and was numerically less frequent in patients with irAEs.

CONCLUSION

PAD exacerbations in the context of ICI treatment are common, although generally mild, and occur despite background immunosuppression. Exacerbations are more frequent and severe in patients on more intensive immunosuppressive therapies pre-immunotherapy.

The PD-1/PD-L pathway in rheumatic diseases

BACKGROUND/PURPOSE

Autoimmune diseases are diseases in which the body produces an abnormal immune response to self-antigens and damages its own tissues. Programmed death-1 (PD-1) and its ligands (PD-Ls) have been discovered to be important negative regulators of the immune system, playing crucial roles in autoimmunity.

METHODS

We analyzed the existing scientific literature dealing with this issue. In this review, the PD-1/PD-L pathway in the genetic susceptibility to and pathogenesis of rheumatic diseases is discussed. The PD-1/PD-L pathway might be helpful for diagnosing, evaluating the disease activity of and treating rheumatic diseases.

RESULTS

PD-1/PD-L gene polymorphisms are associated with a genetic predisposition to rheumatic disorders, which can provide reference information for diagnosis and disease activity. The conclusion of the crucial role of the PD-1/PD-L pathway in the pathogenesis of rheumatic diseases is consistent, but the details remain controversial. In some animal models, manipulating the PD-1/PD-L pathway could decrease disease severity. PD-1/PD-Ls may enable us to develop new therapeutics for patients with rheumatic diseases in the future.

CONCLUSION

The PD-1/PD-L pathway plays crucial roles in rheumatic disease. More work is needed to provide a better mechanistic understanding of the PD-1/PD-L pathway and to facilitate the precise therapeutic manipulation of this pathway.

The diagnostic work-up of cancer-associated myositis

PURPOSE OF REVIEW

Despite the well-recognized association between malignancy and myositis, definite data indicating the best strategy for diagnosing cancer in myositis patients is lacking. In this article, we review the data on cancer screening in patients with myositis, and propose an algorithm for this purpose based on recently published data.

RECENT FINDINGS

Evidence has recently emerged supporting blind screening in patients with certain myositis phenotypes. In addition to the clinical examination, imaging techniques such as PET/computed tomography scanning and whole-body MRI, and determination of the autoantibody profile beyond anti-TIF1γ antibody, the well known cancer biomarker in dermatomyositis, will help the clinician face this complex clinical situation. Molecules related to the checkpoint inhibitor pathway, specifically soluble programmed death 1, may also have a role in the diagnostic work-up of cancer in myositis. In the future, blood tests analysing circulating DNA will certainly help in detecting patients with cancer-associated myositis (CAM).

SUMMARY

A step forward has been achieved in the pathway to establish optimal cancer screening for myositis patients. International consensus guidelines for an effective diagnostic work-up of CAM are in progress and will be of paramount importance to improving the outcome in these patients.

Malignancy and myositis, from molecular mimicry to tumor infiltrating lymphocytes

Cancer-associated dermatomyositis provides a unique opportunity to explore the relationship between autoimmunity and cancer. In this review, we describe the related epidemiological issues, considering the various currently accepted myositis phenotypes, their link with cancer, and the possible mechanisms leading to this relationship. We discuss current evidence regarding the role of molecular mimicry, somatic DNA tumor mutations, and the PD-1/PD-L1 pathway in the association between cancer and myositis. We also review tumor-infiltrating lymphocytes as a relevant factor to be evaluated in cancer-associated myositis, their interaction with tumor neoantigens, and the tumor mutational burden, all of which have implications for the treatment of these patients with immunotherapy. Finally, we discuss clinical scenarios related to the relationship between cancer and myositis, delineating a comprehensive theory linking autoimmunity and cancer.

Dermatomyositis: Diagnosis and treatment

The second article in this continuing medical education series reviews the initial evaluation of patients with suspected dermatomyositis (DM), the relevant work-up for malignancy and interstitial lung disease once a diagnosis of DM is made, and treatment recommendations for patients with DM based on disease severity, the presence of systemic symptoms, and myositis-specific antibody (MSA) profiles. This review emphasizes the emerging role of MSAs in the diagnosis of DM and highlights how MSAs can be used to guide the appropriate work-up for malignancy and interstitial lung disease. The treatment approach proposed by this continuing medical education series discusses both established and novel therapies for DM and highlights the importance of considering lesion type, degree of muscle involvement, presence of systemic symptoms, presence of MSAs, and patient age when determining the best treatment approach for a patient with DM.

Biomarkers in Adult Dermatomyositis: Tools to Help the Diagnosis and Predict the Clinical Outcome

Dermatomyositis pathophysiology is complex. In recent years, medical research has identified molecules associated with disease activity. Besides providing insights into the driving mechanisms of dermatomyositis, these findings could provide potential biomarkers. Activity markers can be used to monitor disease activity in clinical trials and may also be useful in daily practice. This article reviews molecules that could be used as biomarkers for diagnosis and monitoring dermatomyositis disease activity.

Association of antinuclear antibody status with clinical features and malignancy risk in adult-onset dermatomyositis

BACKGROUND

The clinical significance of antinuclear antibody (ANA) status in adults with dermatomyositis (DM) has yet to be fully defined.

OBJECTIVE

We compared the incidence of amyopathic disease, risk of malignancy, and clinical findings in ANA⁺ and ANA^- patients with adult-onset DM.

METHODS

This was a retrospective cohort study of patients with ANA⁺ or ANA^- adult-onset DM determined by enzyme-linked immunosorbent assay.

RESULTS

Of 231 patients, 140 (61%) were ANA⁺ and 91 (39%) were ANA^-. Compared with the ANA^- patients, the ANA⁺ patients had a lower frequency of dysphagia (15% vs 26% [P = .033]) and heliotrope rash (38% vs 53% [P = .026]). In all, 54 patients (23%) developed malignancy within 3 years of diagnosis of their DM; 11% of the ANA⁺ patients developed malignancy versus 43% of the ANA^- patients (P < .001). There was a strong association between ANA positivity and lower likelihood of malignancy in multivariable analysis (odds ratio, 0.16; P < .001). Conversely, ANA positivity was not associated with amyopathic disease (odds ratio, 0.94; P = .87).

LIMITATIONS

The retrospective nature of the study was a limitation.

CONCLUSION

In patients with adult-onset DM, ANA negativity is associated with increased likelihood of development of malignancy within 3 years of diagnosis of their DM. Particularly close follow-up and frequent malignancy screening may be warranted in ANA^- individuals with DM.

PD-1 immunobiology in systemic lupus erythematosus

Programmed death (PD)-1 receptors and their ligands have been identified in the pathogenesis and development of systemic lupus erythematosus (SLE). Two key pathways, toll-like receptor and type I interferon, are significant to SLE pathogenesis and modulate the expression of PD-1 and the ligands (PD-L1, PD-L2) through activation of NF-κB and/or STAT1. These cell signals are regulated by tyrosine kinase (Tyro, Axl, Mer) receptors (TAMs) that are aberrantly activated in SLE. STAT1 and NF-κB also exhibit crosstalk with the aryl hydrocarbon receptor (AHR). Ligands to AHR are identified in SLE etiology and pathogenesis. These ligands also regulate the activity of the Epstein-Barr virus (EBV), which is an identified factor in SLE and PD-1 immunobiology. AHR is important in the maintenance of immune tolerance and the development of distinct immune subsets, highlighting a potential role of AHR in PD-1 immunobiology. Understanding the functions of AHR ligands as well as AHR crosstalk with STAT1, NF-κB, and EBV may provide insight into disease development, the PD-1 axis and immunotherapies that target PD-1 and its ligand, PD-L1.

Increased levels of soluble co-stimulatory molecule PD-L1 (B7-H1) in the plasma of viraemic HIV-1+ individuals

Recent evidence has revealed that PD-L1 is expressed in two functional forms, namely, a membrane-bound form (mPD-L1) and a soluble form (sPD-L1). The identification of the soluble form of PD-L1 represents the discovery of a new potential mechanism for the activation of the PD-1 pathway that may mediate a physiological apoptotic mechanism through a cell-cell signalling-independent pathway and may also favour T cell dysfunction during HIV infection. Since the presence of sPD-L1 has not been well established in the scenario of chronic viral infection, we investigated the presence of sPD-L1 in the plasma of viraemic HIV⁺ individuals and the potential mechanism that promotes its production. We report the following: 1) the level of the soluble form of PD-L1 is increased in the plasma of viraemic HIV⁺ individuals, 2) the level of the soluble form of PD-L1 in viraemic HIV⁺ individuals correlates with markers of microbial product translocation and inflammation, 3) the expression of the membrane-bound form of PD-L1 on conventional dendritic cells from viraemic HIV⁺ individuals correlates with the levels of soluble PD-L1 and MMP-2, and 4) monocyte-derived dendritic cells not only increase their expression of mPD-L1 and MMP-2 but also produce sPD-L1 after LPS and TNF-α stimulation, as demonstrated by functional in vitro experiments, which provides insight into the potential source of sPD-L1 production.