The Need for Classification Criteria of Immune Checkpoint Inhibitor-induced inflammatory Arthritis: A Scoping Review

Immune checkpoint inhibitor-induced inflammatory arthritis (ICI-IA) is an immune-related adverse event that can occur as a result of receiving ICIs for cancer treatment. Thus far, ICI-IA has been described variably in the literature, in part due to varying presentations that evolve over time, as well as a lack of standardized definitions and classification. This scoping review aggregates various descriptions of ICI-IA, highlighting the most prominent attributes of ICI-IA from categories such as symptoms, signs, imaging, and laboratory findings as well as discussing potential mimic conditions.

Identification of outcome domains in immune checkpoint inhibitor-induced inflammatory arthritis and polymyalgia rheumatica: A scoping review by the OMERACT irAE working group

INTRODUCTION

Immune checkpoint inhibitors (ICI), increasingly used cancer therapeutics, can cause off-target inflammatory effects called immune-related adverse events (irAEs), including ICI-induced inflammatory arthritis (ICI-induced IA) and polymyalgia rheumatica (ICI-induced PMR). There are no validated classification criteria or outcome measures for these conditions, and adaptation of treatment recommendations from corresponding rheumatic diseases may not be appropriate. We summarized clinical descriptors of ICI-induced IA and ICI-induced PMR and aggregated domains used for these conditions in order to inform the development of a core set of outcome domains.

METHODS

As the initial step of the core domain set generation process, we systemically searched Medline (Pubmed), EMBASE, Cochrane, and CINHL through March 2021 to identify all studies that provide both clinical descriptions and domains relevant to ICI-induced IA and ICI-induced PMR. Domains were mapped to core areas, such as pathophysiological manifestations, life impact, resource use, and longevity/survival, as suggested by the OMERACT 2.1 Filter.

RESULTS

We identified 69 publications, over a third of which utilized non-specific diagnoses of "arthritis," "arthralgia," and/or "PMR". Other publications provided the number, the distribution and/or names of specific joints affected, while others labeled the irAE as the corresponding rheumatic disease, such as rheumatoid arthritis or spondyloarthritis. Most distinct domains mapped to the pathophysiology/manifestations core area (24 domains), such as signs/symptoms (13 domains), labs (6 domains), and imaging (5 domains), with harm domains of adverse effects from irAE treatment and fear of irAE treatment decreasing ICI efficacy. Forty-three publications also referenced irAE treatment and 35 subsequent response, as well as 32 tumor response.

CONCLUSION

There is considerable heterogeneity in the domains used to clinically characterize ICI-induced IA and ICI-induced PMR. There were several domains mapped to the pathophysiologic manifestations core area, although several publications highlighted domains evenly distributed among the other core areas of life impact, longevity/survival and resource use.

Pathogenesis and Treatment of T-Large Granular Lymphocytic Leukemia (T-LGLL) in the Setting of Rheumatic Disease

A complex relationship exists between rheumatic diseases and cancer. This delicate balance between chronic inflammation and malignant cell transformation in hematologic neoplasms has been observed, but is not well defined. Large Granular Lymphocyte (LGL) leukemia is at the intersection of a clonal lymphoproliferative disease, chronic inflammation, and autoimmunity. The association between rheumatoid arthritis (RA) and the spectrum of Felty’s Syndrome is well-known. Other rheumatic disorders have been reported including systemic lupus erythematosus (SLE), Sjogren’s Syndrome (SS), vasculitis, Behcet’s Disease (BD) and systemic sclerosis. The association between T-LGLL and rheumatic disease pathogenesis has been hypothesized, but has not yet been fully understood. Components of a shared pathogenesis includes chronic antigen stimulation, JAK-STAT pathway activation and overlap of various cytokines. We will summarize current knowledge on the molecular understanding between T-LGLL and rheumatic disease. There are many potential areas of research to help meet this need and lead to development of targeted therapeutic options.

Incidence, Treatment, and Survival of Patients With T-Cell Lymphoma, T-Cell Large Granular Leukemia, and Concomitant Plasma Cell Dyscrasias

T-Cell malignancies are a group of heterogeneous disorders composed of primary cutaneous T-cell lymphomas (CTCLs), peripheral T-cell lymphomas (PTCLs), and T-cell leukemias, including T-cell large granular lymphocytic leukemia (T-LGLL). Cases of patients with combined T-cell malignancies and plasma cell dyscrasias (PCD) are reported in the literature, but these are mostly limited to case reports or small case series with <10 patients. Here, we described the clinical course of 26 patients and report baseline characteristics and clinical outcomes including overall survival (OS), progression-free survival (PFS), and objective response rates (ORRs) in this unique population. There was no survival difference in patients with CTCL or T-LGLL and concomitant PCD when treated with standard therapy directed at the T-cell malignancy when compared to historical controls. However, patients with PTCL and concomitant PCD had significantly inferior outcomes with rapid progression and worse OS and PFS at 1.7 years (p=0.006) and 4.8 months (p=0.08), respectively, when compared to historical controls for patients with PTCL, although the limited number of patients included in this analysis precludes drawing definitive conclusions. Treatment directed at the T-cell malignancy resulted in the eradication of the PCD clone in multiple patients (15.4%) including one with multiple myeloma (MM) who experienced a complete response after starting therapy directed at the T-cell malignancy. For patients with T-cell malignancies and concomitant PCD, treatment with standard T-cell-directed therapies is recommended based on this analysis with continued follow-up and monitoring of the concomitant PCD. Further studies are needed to definitively elucidate the increased risk of relapse in patients with PTCL and concomitant PCD, and larger, multi-center cohorts are needed to validate these findings across T-cell malignancies and PCDs.

Giant cell arteritis associated with PD-1 inhibition

A 50-year-old woman was referred to rheumatology for new onset polyarthralgia and headache. She had a history of metastatic lung adenocarcinoma and was started on treatment with the programmed death 1 receptor (PD-1) antagonist pembrolizumab 2 months prior. Examination revealed left temporal artery tenderness and hand synovitis. Investigations revealed enlarged temporal artery on ultrasound imaging. On steroid treatment, she had resolution of symptoms, but due to significant steroid side effects required methotrexate and her PD-1 antagonist therapy was continued in consultation with her oncologist. Her malignant disease has remained stable, and she has improved functional status.

A Systematic Review of the Inclusion of Non-Inflammatory Ultrasonographic Enthesopathy Findings in Enthesitis Scoring Indices

Ultrasound has advanced the diagnosis and management of patients with inflammatory rheumatic conditions. It can be used to identify and monitor enthesitis, a cardinal feature of spondyloarthropthies. Several enthesitis scoring systems utilizing ultrasound to determine entheseal involvement have been developed. These scoring systems generally rely on determining the presence or absence of erosions, tendon enlargement, power Doppler signal, or enthesophytes. This systematic review identified ultrasound scoring systems that have been utilized for evaluating enthesitis and what key components derive the score. Review of these scoring systems, however, demonstrated confounding as some of the score components including enthesophytes may be seen in non-inflammatory conditions and some components including erosions can be seen from chronic damage, but not necessarily indicate active inflammatory disease. What is furthermore limiting is that currently there is not an agreed upon term to describe non-inflammatory enthesopathies, further complicating these scoring systems. This review highlights the need for a more comprehensive ultrasound enthesopathy scoring index.