Severe cardiotoxicity in 2 patients with thymoma receiving immune checkpoint inhibitor therapy: A case report

Progressed Atrioventricular Block in Immune Checkpoint Inhibitor Induced Myocarditis: A Case Report

Immune checkpoint inhibitor (ICI) has demonstrated promising results in treating various cancers, but its associated cardiotoxicity, especially ICI-associated myocarditis, presents a serious concern. We reported a case of a 63-year-old male who complained of progressive dyspnea after tislelizumab, a novel humanized anti-PD-1 monoclonal antibody, for hepatocellular carcinoma. Upon diagnosing ICI-related myocarditis, corticosteroid therapy was initiated immediately. The elevated biomarkers quickly decreased, but the atrioventricular block progressed from first-degree to third-degree, necessitating pacemaker implantation. This is the first report of complete AVB consecutive to tislelizumab-induced myocarditis, highlighting the importance of early corticosteroid therapy and continuous electrocardiography monitoring.

Steroid-Refractory Myocarditis Induced by Immune Checkpoint Inhibitor Responded to Infliximab: Report of Two Cases and Literature Review

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death protein 1 and its ligand (PD-1/PD-L1) as well as anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4), have been widely used for treating solid tumors. Myocarditis is a potentially lethal immune-related adverse events (irAEs) caused by ICIs therapy. The treatment of steroid-refractory myocarditis is challenging. We reported two non-small-cell lung cancer patients with steroid-refractory myocarditis induced by ICI. The symptoms were not resolved after pulse corticosteroid therapy and subsequent treatment including intravenous immunoglobulin and mycophenolate mofetil. Considering the level of serum interleukin (IL)-6 decreased by > 50% and level of serum tumor necrosis factor-α (TNF-α) increased during the course of the disease, infliximab was used. Myocarditis gradually alleviated after infliximab treatment. The cases revealed that specific cytokine inhibitors have promising roles in the treatment of steroid-refractory myocarditis. Infliximab could be considered for patients with low level of IL-6 and elevated level of TNF-α.

Advanced three-dimensional X-ray imaging unravels structural development of the human thymus compartments

BACKGROUND

The thymus, responsible for T cell-mediated adaptive immune system, has a structural and functional complexity that is not yet fully understood. Until now, thymic anatomy has been studied using histological thin sections or confocal microscopy 3D reconstruction, necessarily for limited volumes.

METHODS

We used Phase Contrast X-Ray Computed Tomography to address the lack of whole-organ volumetric information on the microarchitecture of its structural components. We scanned 15 human thymi (9 foetal and 6 postnatal) with synchrotron radiation, and repeated scans using a conventional laboratory x-ray system. We used histology, immunofluorescence and flow cytometry to validate the x-ray findings.

RESULTS

Application to human thymi at pre- and post-natal stages allowed reliable tracking and quantification of the evolution of parameters such as size and distribution of Hassall's Bodies and medulla-to-cortex ratio, whose changes reflect adaptation of thymic activity. We show that Hassall's bodies can occupy 25% of the medulla volume, indicating they should be considered a third thymic compartment with possible implications on their role. Moreover, we demonstrate compatible results can be obtained with standard laboratory-based x-ray equipment, making this research tool accessible to a wider community.

CONCLUSIONS

Our study allows overcoming the resolution and/or volumetric limitations of existing approaches for the study of thymic disfunction in congenital and acquired disorders affecting the adaptive immune system.

Sintilimab-induced myocarditis suspected in a patient with esophageal cancer and followed septic shock: case report and literature review

Background

Immune checkpoint inhibitors (ICIs) have become a prevalent tool in anti-tumor therapy in recent years. They may cause immune-related adverse events (irAEs) including potentially life-threatening cardiovascular toxicities such as myocarditis.

Case presentation

In this report, we describe a 69-year-old man with recurrent esophageal cancer who developed myocarditis after receiving three cycles of sintilimab combined with nab-paclitaxel. Despite a rising cardiac troponin I (cTnI), he initially reported no discomfort. He was later suspected of having with sintilimab-induced myocarditis. Although treatment with methylprednisolone reduced his cTnI levels, he still experienced significant discomfort. Moreover, he developed pneumonia and septic shock.

Conclusion

In our literature search to identify all reported cases of sintilimab-associated adverse events involving myocarditis, we found 14 patients, including those with esophageal cancer, thymoma, lung cancer, gastric cancer, hepatobiliary carcinoma, and chordoma. The primary treatment for ICI-induced cardiotoxicity is methylprednisolone. However, the long-term or high-dose use of steroids can also induce side effects, which have not been the focus of these case reports. This is the first reported case of asymptomatic immune-mediated myocarditis occurring during the treatment of esophageal cancer with sintilimab. It is also the first to address the side effects of methylprednisolone used in the treatment of sintilimab-related myocarditis. To facilitate an early diagnosis, regular monitoring is required during sintilimab treatment. We should also focus on the prevention and management of adverse effects related to steroid use.

Therapeutic agents for steroid-refractory immune checkpoint inhibitor-related myocarditis: a narrative review

Background and Objective

Immune checkpoint inhibitors (ICIs) have become one of the cornerstones of current oncology treatment, and immune checkpoint inhibitor-related myocarditis (IRM) is the most fatal of all immune checkpoint inhibitor-related adverse events (irAEs). Methylprednisolone pulse therapy (500-1,000 mg/day) is the initial treatment for IRM recommended by almost all relevant guidelines. However, subsequent treatment regimens remain unclear for patients who do not respond to methylprednisolone pulse therapy (who are defined as steroid-refractory patients). We propose a potential treatment approach for steroid-refractory IRM.

Methods

The PubMed and the Cochrane Library databases were searched using keywords related to IRM. Relevant English-language articles published from January 2000 to February 2024 were included in this narrative review.

Key Content and Findings

Abatacept is the preferred choice for the treatment of isolated steroid-refractory IRM. For rapidly progressive or interleukin-6 abnormally elevated steroid-refractory IRM, alemtuzumab or tocilizumab/tofacitinib are the preferred therapeutic agents, respectively. For steroid-refractory IRM comorbid with myositis or comorbid with myasthenia gravis, abatacept + ruxolitinib/mycophenolate mofetil (MMF)/intravenous immunoglobulin (IVIG), or MMF + pyridostigmine/IVIG are the preferred therapeutic agents, respectively.

Conclusions

The pathogenesis of steroid-refractory IRM and the treatment regimen remain unclear. A large number of studies need to be conducted to validate or update our proposed treatment approach.

Treatment of Immune Checkpoint Inhibitor-associated Myocarditis

ABSTRACT

Immune checkpoint inhibitors (ICIs) are a form immunotherapy where the negative regulators of host immunity are targeted, thereby leveraging the own immune system. ICIs have significantly improved cancer survival in several advanced malignancies, and there are currently more than 90 different cancer indications for ICIs. Most patients develop immune-related adverse events during ICI therapy. Most are mild, but a small subset of patients will develop severe and potentially fatal immune-related adverse events. A serious cardiovascular complication of ICI therapy is myocarditis. Although the incidence of myocarditis is low, mortality rates of up to 50% have been reported. The mainstay of ICI-associated myocarditis treatment is high-dose corticosteroids. Unfortunately, half of patients with myocarditis do not show clinical improvement after corticosteroid treatment. Also, high doses of corticosteroids may adversely impact cancer outcomes. There is an evidence gap in the optimal second-line treatment strategy. Currently, there is a paradigm shift in second-line treatment taking place from empirical corticosteroid-only strategies to either intensified initial immunosuppression where corticosteroids are combined with another immunosuppressant or targeted therapies directed at the pathophysiology of ICI myocarditis. However, the available evidence to support these novel strategies is limited to observational studies and case reports. The aim of this review is to summarize the literature, guidelines, and future directions on the pharmacological treatment of ICI myocarditis.

Current Treatment Approaches for Thymic Epithelial Tumors

Thymic epithelial tumors (TETs), including thymoma, thymic carcinoma and neuroendocrine tumors, are uncommon tumors that originate from the epithelial cells of the thymus. Nevertheless, despite their rarity, they represent the most common tumor type located in the anterior mediastinum. Therapeutic choices based on staging and histology may include surgery with or without neoadjuvant or adjuvant therapy represented by chemotherapy, radiotherapy or chemo-radiotherapy. For patients with advanced or metastatic TETs, platinum-based chemotherapy remains the standard first-line treatment; however, some new drugs and combinations are currently under evaluation. In any case, proper management of patients with TETs requires a multidisciplinary team approach to personalize care for each patient.