Insights into Potential Pathogenesis and Treatment Options for Immune-Checkpoint Inhibitor-Related Pneumonitis

Immune checkpoint inhibitor therapy‑related pneumonitis: How, when and why to diagnose and manage (Review)

Immune checkpoint inhibitor (ICI) therapy has revolutionized cancer treatment by enhancing the immune response against tumor cells. However, their influence on immune pathways can lead to immune-related adverse events such as pneumonitis, necessitating rapid diagnosis and management to prevent severe complications. These adverse events arise from the activation of the immune system by immunotherapeutic drugs, leading to immune-mediated inflammation and tissue damage in various organs and tissues throughout the body. The present review article discusses the pathophysiology, clinical presentation, diagnostic modalities and management strategies for ICI-related pneumonitis, emphasizing early recognition and tailored interventions. Future research endeavors should focus on elucidating the underlying mechanisms of pneumonitis and identifying predictive biomarkers to guide personalized treatment strategies in this evolving field of oncology.

The application of bronchoscopy in the assessment of immune checkpoint inhibitor-related pneumonitis severity and recurrence

To explore the role of bronchoscopy for the assessment of checkpoint inhibitor pneumonitis (CIP), a retrospective single-center study was conducted to assess patients diagnosed with CIP at grade 2 or above and also underwent bronchoscopy between January 2020 and December 2022. Clinical data and bronchoscopic findings were recorded. The treatment data and prognosis information were collected. Twenty-one patients who underwent bronchoscopy and were diagnosed with CIP were enrolled in this study. All patients underwent bronchoalveolar lavage fluid (BALF) analysis. Of them, T lymphocyte subsets of BALF were tested in 15 cases. Transbronchial cryobiopsy (TBCB) was performed in 8 patients, and transbronchial lung biopsy was performed in 5 patients. 3 patients developed pneumothorax after TBCB and all recovered without serious compilations.14 patients experienced grade 2 CIP, while 7 patients ≥ grade 3 CIP. Symptoms were improved in 19 (90.5%) patients after standard treatment adhering to CIP guidelines. However, 5 patients relapsed during steroid tapering. Factors related to the severity and recurrence of CIP were analyzed. Patients with previous interstitial lung disease (ILD) were more likely to develop high grade CIP than those without [83.3% (5/6) versus 15.4% (3/15), P = 0.011].The odds ratio (OR) was 32.5 (95% CI 2.284-443.145, P = 0.009). Increased BALF lymphocyte percentage was associated with high grade CIP, OR 1.095 (95% CI 1.001-1.197, P = 0.047), and higher possibility of CIP relapse, OR 1.123 (95% CI, 1.005-1.225, P = 0.040). Lymphocyte subsets were tested in 15 patients. CD4/CD8 > 1 was found in 80% (4/5) of relapsed patients and 20% (2/10) of patients without relapse (P = 0.047). The OR was 16.00 (95% CI 1.093-234.24, P = 0.043). In this retrospective study, patients with previous ILD was more likely to develop high grade CIP. Higher lymphocyte percentage in BALF was associated with high grade CIP and susceptibility to relapse during treatment of CIP. A CD4/CD8 ratio greater than 1 in lymphocyte subsets of BALF was associated with higher possibility of CIP relapse. We found that TBCB is a safe procedure in CIP patients.

Exploratory mass cytometry analysis reveals immunophenotypes of cancer treatment-related pneumonitis

Anticancer treatments can result in various adverse effects, including infections due to immune suppression/dysregulation and drug-induced toxicity in the lung. One of the major opportunistic infections is Pneumocystis jirovecii pneumonia (PCP), which can cause severe respiratory complications and high mortality rates. Cytotoxic drugs and immune-checkpoint inhibitors (ICIs) can induce interstitial lung diseases (ILDs). Nonetheless, the differentiation of these diseases can be difficult, and the pathogenic mechanisms of such diseases are not yet fully understood. To better comprehend the immunophenotypes, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid from patients with PCP, cytotoxic drug-induced ILD (DI-ILD), and ICI-associated ILD (ICI-ILD) using two panels containing 64 markers. In PCP, we observed an expansion of the CD16+ T cell population, with the highest CD16+ T proportion in a fatal case. In ICI-ILD, we found an increase in CD57+ CD8+ T cells expressing immune checkpoints (TIGIT+ LAG3+ TIM-3+ PD-1+), FCRL5+ B cells, and CCR2+ CCR5+ CD14+ monocytes. These findings uncover the diverse immunophenotypes and possible pathomechanisms of cancer treatment-related pneumonitis.

Efficacy and adverse events of immune checkpoint inhibitors in esophageal cancer patients: Challenges and perspectives for immunotherapy

Esophageal cancer (EC) is the seventh most common cancer worldwide. Patients with EC have a generally poor prognosis mainly due to the lack of effective treatments. Cancer immunotherapy is a promising novel treatment option for EC. This literature review investigated the clinical efficacy of immunotherapy either alone or in combination with chemotherapy or targeted therapy. In addition, we analyzed the adverse events associated with immune checkpoint inhibitors (ICIs). In conclusion, ICIs increase the efficacy of EC treatments, thereby improving the outcomes of EC patients. The findings of this study may help enhance the response to immunotherapy, diminish toxicity, and thus eventually improve medical care for patients with EC.

Corticosteroid-resistant immune-related adverse events: a systematic review

Immune checkpoint inhibitor (ICI) treatment has become an important therapeutic option for various cancer types. Although the treatment is effective, ICI can overstimulate the patient's immune system, leading to potentially severe immune-related adverse events (irAEs), including hepatitis, colitis, pneumonitis and myocarditis. The initial mainstay of treatments includes the administration of corticosteroids. There is little evidence how to treat steroid-resistant (sr) irAEs. It is mainly based on small case series or single case reports. This systematic review summarizes available evidence about sr-irAEs. We conducted a systematic literature search in PubMed. Additionally, we included European Society for Medical Oncology, Society for Immunotherapy of Cancer, National Comprehensive Cancer Network and American Society of Clinical Oncology Guidelines for irAEs in our assessment. The study population of all selected publications had to include patients with cancer who developed hepatitis, colitis, pneumonitis or myocarditis during or after an immunotherapy treatment and for whom corticosteroid therapy was not sufficient. Our literature search was not restricted to any specific cancer diagnosis. Case reports were also included. There is limited data regarding life-threatening sr-irAEs of colon/liver/lung/heart and the majority of publications are single case reports. Most publications investigated sr colitis (n=26), followed by hepatitis (n=21), pneumonitis (n=17) and myocarditis (n=15). There is most data for mycophenolate mofetil (MMF) to treat sr hepatitis and for infliximab, followed by vedolizumab, to treat sr colitis. Regarding sr pneumonitis there is most data for MMF and intravenous immunoglobulins (IVIG) while data regarding infliximab are conflicting. In sr myocarditis, most evidence is available for the use of abatacept or anti-thymocyte globulin (ATG) (both with or without MMF) or ruxolitinib with abatacept. This review highlights the need for prompt recognition and treatment of sr hepatitis, colitis, pneumonitis and myocarditis. Guideline recommendations for sr situations are not defined precisely. Based on our search, we recommend-as first line treatment-(1) MMF for sr hepatitis, (2) infliximab for sr colitis, followed by vedolizumab, (3) MMF and IVIG for sr pneumonitis and (4) abatacept or ATG (both with or without MMF) or ruxolitinib with abatacept for sr myocarditis. These additional immunosuppressive agents should be initiated promptly if there is no sufficient response to corticosteroids within 3 days.

Pulmonary toxicity of immune checkpoint immunotherapy

Cancer remains a leading cause of mortality on a global scale. Lung cancer, specifically non-small cell lung cancer (NSCLC), is a prominent contributor to this burden. The management of NSCLC has advanced substantially in recent years, with immunotherapeutic agents, such as immune checkpoint inhibitors (ICIs), leading to improved patient outcomes. Although generally well tolerated, the administration of ICIs can result in unique side effects known as immune-related adverse events (irAEs). The occurrence of irAEs involving the lungs, specifically checkpoint inhibitor pneumonitis (CIP), can have a profound effect on both future therapy options and overall survival. Despite CIP being one of the more common serious irAEs, limited treatment options are currently available, in part due to a lack of understanding of the underlying mechanisms involved in its development. In this Review, we aim to provide an overview of the epidemiology and clinical characteristics of CIP, followed by an examination of the emerging literature on the pathobiology of this condition.

Immune checkpoint inhibitor-related chronic pneumonitis: a case report and literature review

Immune checkpoint inhibitor (ICI)-related chronic pneumonitis is rare. Limited information is available on the characteristics of this condition. Herein, we present the case of a 54-year-old man with recurrent severe ICI-related pneumonitis. The patient developed fever and dyspnea during both episodes of pneumonitis. He had been previously diagnosed with gastric signet ring cell carcinoma and was undergoing treatment with an anti-PD-1 combination chemotherapy regimen. We reviewed previous case reports of ICI-related pneumonitis according to the primary cancer, time of onset in relation to ICI therapy and chest imaging findings. ICI-related pneumonitis can progress to chronic pneumonitis. Repeated computed tomography imaging showing lung changes in the same location may help to make the diagnosis.

Lung Transplantation for Pleuroparenchymal Fibroelastosis: A Single-Center Experience with Revision of Literature

Pleuroparenchymal fibroelastosis (PPFE) is a rare condition characterized by fibrosis involving the pleura and the upper lobes which can be idiopathic or secondary to chemotherapy, transplantations and occupational exposure. For the end-stage form, lung transplantation (LT) is the treatment of choice. The aim of this study was to report our single-center experience for patients subjected to LT for PPFE and comparing it with the already published evidence on this topic. At our center, we have performed 6 bilateral LTs for patients with PPFE (3 males and 3 females) with a median age of 52 years. Median ICU and in-hospital length of stay were 8 and 30 days, respectively. To date, two patients are alive and four are dead, with a median overall survival of 10 months. In addition, after a formal search using the terms "pleuroparenchymal fibroelastosis AND lung transplantation", we collected 14 studies focused on outcomes after LT. LT for PPFE is technically challenging and its post-operative course could also be complicated. Current available data on LT outcomes are extremely poor and mostly limited to case reports. Further studies need to be published to improve knowledge of this disease and to achieve best outcomes for LT.

Immune checkpoint inhibitor-related pneumonitis and COVID-19: a case-matched comparison of CT findings

OBJECTIVES

To compare the radiological findings of immune checkpoint inhibitor-related pneumonitis (IRP) and COVID-19 pneumonia, evaluating the potential of the CO-RADS score to differentiate between them.

METHODS

Two readers blindly reviewed chest CTs from age- and sex-matched groups of 33 patients with IRP and 33 patients with COVID-19 pneumonia. Each examiner evaluated the presence of 13 CT features, semiquantitatively scored lung involvement, and assigned a CO-RADS score. Inter-reader reliability in the assessment of CT features and CO-RADS categories was evaluated with Cohen's κ. Distribution differences between groups were evaluated with the χ², Fisher's, and Mann-Whitney U tests.

RESULTS

Substantial or higher inter-reader reliability was found in CO-RADS assignments (κ = 0.664) and in the evaluation of CT features (κ ≥ 0.638), among which the sole feature found to significantly differentiate IRP from COVID-19 pneumonia was unilateral presentation (p < 0.001). Lung involvement semiquantitative scores and CO-RADS scores were significantly higher (p < 0.001) in COVID patients (median involvement score 4, IQR 4-6; median CO-RADS score 5, IQR 4-5) than in IRP patients (median involvement score 2.5, IQR 2-4; median CO-RADS score 3, IQR 3-4) but exploratory analysis of CO-RADS specificity revealed comparatively low values, ranging between 51.5% (Reader 1) and 54.6% (Reader 2).

CONCLUSIONS

CT features of IRP and COVID-19 pneumonia frequently overlap, save for the extent of lung involvement and bilaterality. In the current SARS-CoV-2 pandemic, the low specificity of the CO-RADS score for the differential diagnosis of COVID-19 pneumonia and IRP may prompt to reconsider the role of imaging in IRP work-up.

Late-onset toxicities of monoclonal antibodies in cancer patients

Cancer therapy duration is variable and may take years, adding a new challenge of maintaining the best life quality for cancer survivors. In cancer patients, late-onset toxicities have been reported with monoclonal antibodies and may involve several body organs or systems. They are defined as an autoimmune illnesses that can happen months to years after treatment discontinuation. Late-onset toxicities have become a focus of clinical care and related research. After cancer therapy is completed, the patient should receive longitudinal follow-up to detect these late effects as early as possible. The current review summarizes the recently reported late-onset toxicities of four classes of monoclonal antibodies (anti-CD52, anti-CTLA-4, anti-PD-1 and anti-CD20) with guidance for the diagnostic tools, appropriate management and treatment.

Mechanisms of dermatologic toxicities to immune checkpoint inhibitor cancer therapies

The discovery of immune checkpoint inhibition (ICI) sparked a revolution in the era of targeted anticancer therapy. While monoclonal antibodies targeting the CTLA-4 and PD-1 axes have improved survival in patients with advanced cancers, these immunotherapies are associated with a wide spectrum of dermatologic immune-related adverse events (irAEs). Several publications have addressed the clinical and histopathologic classification of these skin-directed irAEs, their impact on antitumor immunity and survival, and the critical role of supportive oncologic dermatology in their management. Here, we review the current understanding of the mechanistic drivers of immune-related skin toxicities with a focus on inflammatory, immunobullous, melanocyte/pigment-related reactions. We detail the specific immune-based mechanisms that may underlie different cutaneous reactions. We also discuss potential mechanisms as they relate to non-cutaneous irAEs and potential overlap with cutaneous irAEs, techniques to study differences in immune-related versus de novo skin reactions, and how treatment of these adverse events impacts cancer treatment, patient quality of life, and overall survival. An improved understanding of the mechanistic basis of cutaneous irAEs will allow us to develop and utilize blood-based biomarkers that could help ultimately predict onset and/or severity of these irAEs and to implement rational mechanistic-based treatment strategies that are targeted to the irAEs while potentially avoiding abrogating anti-tumor effect of ICIs.

Cytokine Release Syndrome and Immune-Related Pneumonitis Associated With Tumor Progression in a Pulmonary Pleomorphic Carcinoma Treated With Nivolumab Plus Ipilimumab Treatment: A Case Report

Effective control of severe immune-related adverse events, including cytokine release syndrome (CRS), is essential for the success of immunotherapy. We present a case of a granulocyte colony-stimulating factor–producing pleomorphic lung carcinoma treated with nivolumab plus ipilimumab which developed CRS and severe immune-related pneumonitis. The effect of immunotherapy was heterogeneous; gastric metastasis was eliminated, but the pulmonary lesion had primary resistance. Steroid and tocilizumab were successful in controlling CRS, but additional infliximab was necessary to control pneumonitis. To control immune-related adverse events, it is important to choose immunosuppressive agents to the specific target organ and inflammatory cells.