Cytomegalovirus infection as an underestimated trigger for checkpoint inhibitor-related pneumonitis in lung cancer: a retrospective study

Immune checkpoint inhibitor-related pneumonitis: research advances in prediction and management

The advent of immune-checkpoint inhibitors (ICIs) has revolutionized the treatment of malignant solid tumors in the last decade, producing lasting benefits in a subset of patients. However, unattended excessive immune responses may lead to immune-related adverse events (irAEs). IrAEs can manifest in different organs within the body, with pulmonary toxicity commonly referred to as immune checkpoint inhibitor-related pneumonitis (CIP). The CIP incidence remains high and is anticipated to rise further as the therapeutic indications for ICIs expand to encompass a wider range of malignancies. The diagnosis and treatment of CIP is difficult due to the large individual differences in its pathogenesis and severity, and severe CIP often leads to a poor prognosis for patients. This review summarizes the current state of clinical research on the incidence, risk factors, predictive biomarkers, diagnosis, and treatment for CIP, and we address future directions for the prevention and accurate prediction of CIP.

Human virome profiling identified CMV as the major viral driver of a high accumulation of senescent CD8+ T cells in patients with advanced NSCLC

Circulating senescent CD8+ T (T8sen) cells are characterized by a lack of proliferative capacities but retain cytotoxic activity and have been associated to resistance to immunotherapy in patients with advanced non-small cell lung cancer (aNSCLC). We aimed to better characterize T8sen and to determine which factors were associated with their accumulation in patients with aNSCLC. Circulating T8sen cells were characterized by a higher expression of SA-βgal and the transcription factor T-bet, confirming their senescent status. Using whole virome profiling, cytomegalovirus (CMV) was the only virus associated with T8sen. CMV was necessary but not sufficient to explain high accumulation of T8sen (T8senhigh status). In CMV+ patients, the proportion of T8sen cells increased with cancer progression. Last, CMV-induced T8senhigh phenotype but not CMV seropositivity itself was associated with worse progression-free and overall survival in patients treated with anti-PD-(L)1 therapy but not with chemotherapy. Overall, CMV is the unique viral driver of T8sen-driven resistance to anti-PD-(L)1 antibodies in patients with aNSCLC.

Pneumocystis jirovecii pneumonia associated with immune checkpoint inhibitors: A systematic literature review of published case reports and disproportionality analysis based on the FAERS database

Background: Pneumocystis jirovecii pneumonia (PJP) has been reported with ICIs but limited to case reports. The clinical features of PJP with ICIs remain mostly unknown. This study aims to investigate the association of PJP with ICIs and describe clinical features.

Methods: Reports of PJP recorded in FAERS (January 2004–December 2022) were identified through the preferred term “Pneumocystis jirovecii pneumonia”. Demographic and clinical features were described, and disproportionality signals were assessed through the Reporting Odds Ratio (ROR) and Information Component (IC), using traditional chemotherapy and targeted therapy as comparators, and adjusting signals by excluding contaminant immunosuppressive drugs and pre-existing diseases. A systematic literature review was conducted to describe clinical features of published PJP reports with ICIs. Bradford Hill criteria was adopted for global assessment of the evidence.

Results: We identified 677 reports of PJP associated with ICIs, in which 300 (44.3%) PJP cases with fatal outcome. Nivolumab (IC025 2.05), pembrolizumab (IC025 1.88), ipilimumab (IC025 1.43), atezolizumab (IC025 0.36), durvalumab (IC025 1.65), nivolumab plus ipilimumab (IC025 1.59) have significant signals compared to other drugs in FAERS database. After excluding pre-existing diseases and immunosuppressive agents which may increase susceptibility of PJP, the signals for PJP associated with nivolumab, pembrolizumab, durvalumab, nivolumab plus ipilimumab remained robust (IC025 > 0). When compared to other anticancer regimens, although all ICIs showed a lower disproportionate signal for PJP than chemotherapy, nivolumab (IC025 0.33, p < 0.001), pembrolizumab (IC025 0.16, p < 0.001), both PD-1 inhibitors, presented a higher signal for PJP than targeted therapy. Male gender (IC025 0.26, p < 0.001) and age >65 years (IC025 0.38, p < 0.001) were predominant in PJP cases associated with across all ICIs. In literature, 15 PJP cases associated with ICIs were reported in 10 published case reports. 12 of 15 (80.0%) of cases received PD-1 inhibitors before PJP was diagnosed.

Conclusion: By the combined analysis of post-marketing data from FAERS and published case reports, we identified ICIs may be associated with PJP, especially in males aged >65years. After accounting for confounders, PD-1 inhibitors emerged with a robust disproportionality signal when compared to PD-L1/CTLA-4 inhibitors as well as targeted therapy. Further research is warranted to validate our findings.

Chinese expert consensus on the multidisciplinary management of pneumonitis associated with immune checkpoint inhibitor

Immune checkpoint inhibitors (ICIs) have successfully treated a number of different types of cancer, which is of great significance for cancer treatment. With the widespread use of ICIs in clinical practice, the increasing checkpoint inhibitor pneumonia (CIP) will be a challenge to clinicians. To guide the diagnosis and treatment of CIP, we conducted in-depth discussions based on the latest evidence, forming a consensus among Chinese experts on the multidisciplinary management of CIP.

Case report: Pneumonia with clinical symptoms precedes imaging evidence after immune checkpoint inhibitors combined with radiotherapy in lung squamous cell cancer

Immune-checkpoint inhibitors (ICI) targeting programmed cell death 1 (PD-1) and its ligand 1 (PD-L1) have quickly changed the treatment landscape in advanced non-small cell lung cancer. However, any patient treated with an immune checkpoint inhibitor is at risk for immune-related adverse events (irAEs). Checkpoint inhibitor pneumonitis (CIP) is a rare but potentially severe pulmonary toxicity of immunotherapy. Since the imaging features and symptoms are not specific, the diagnosis of CIP is challenging. In addition, CIP may mimic other lung diseases. Due to these characteristics, proper patient management may be delayed. So, a comprehensive understanding of imaging features is essential for a prompt detection and correct management of these drug-induced lung diseases. We presented a patient with lung squamous cell cancer who has clinical symptoms preceding imaging evidence of pneumonitis after immunotherapy and radiotherapy. We also discussed the safety of immunotherapy, the complexity and management of immune pneumonitis.

Checkpoint Inhibitor Pneumonitis Induced by Anti-PD-1/PD-L1 Therapy in Non-Small-Cell Lung Cancer: Occurrence and Mechanism

Immune checkpointty inhibitors (ICIs), particularly those targeting programmed death 1 (PD-1) and anti-programmed death ligand 1 (PD-L1), enhance the antitumor effect by restoring the function of the inhibited effector T cells and produce durable responses in a large variety of metastatic and late patients with non-small-cell lung cancer. Although often well tolerated, the activation of the immune system results in side effects known as immune-related adverse events (irAEs), which can affect multiple organ systems, including the lungs. The occurrence of severe pulmonary irAEs, especially checkpoint inhibitor pneumonitis (CIP), is rare but has extremely high mortality and often overlaps with the respiratory symptoms and imaging of primary tumors. The development of CIP may be accompanied by radiation pneumonia and infectious pneumonia, leading to the simultaneous occurrence of a mixture of several types of inflammation in the lungs. However, there is a lack of authoritative diagnosis, grading criteria and clarified mechanisms of CIP. In this article, we review the incidence and median time to onset of CIP in patients with non-small-cell lung cancer treated with PD-1/PD-L1 blockade in clinical studies. We also summarize the clinical features, potential mechanisms, management and predictive biomarkers of CIP caused by PD-1/PD-L1 blockade in non-small-cell lung cancer treatment.

Infections due to dysregulated immunity: an emerging complication of cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionised cancer treatment. However, immune-related adverse events (irAEs) are a common side effect which can mimic infection. Additionally, treatment of irAEs with corticosteroids and other immunosuppressant agents can lead to opportunistic infection, which we have classed as immunotherapy infections due to immunosuppression. However, emerging reports demonstrate that some infections can be precipitated by ICIs in the absence of immunosuppressive treatment, in contrast to the majority of reported cases. These infections are characterised by a dysregulated inflammatory immune response, and so we propose they are described as immunotherapy infections due to dysregulated immunity. This review summarises the rapidly emerging evidence of these phenomena and proposes a new framework for considering infection in the context of cancer immunotherapy.

Immunopathological basis of immune-related adverse events induced by immune checkpoint blockade therapy

Despite the considerable success of cancer immunotherapy with immune checkpoint inhibitors, their nonspecific release of the immunosuppressive mechanism is often associated with immune-related adverse events (irAEs). irAEs significantly disturb patients' quality of life and can even be life-threatening. Therefore, the appropriate management of irAEs is crucial for the development of further reliable cancer immunotherapies. irAEs have the appearance of ordinary autoimmune diseases in one aspect but often have distinct features. Although the detailed pathogenesis of irAEs remains unclear, increasing numbers of studies have provided numerous clues. Here, we review the current knowledge on irAEs, particularly from an immunopathological basis.

Insight for Immunotherapy of HCMV Infection

Human cytomegalovirus (HCMV), a ubiquitous in humans, has a high prevalence rate. Young people are susceptible to HCMV infection in developing countries, while older individuals are more susceptible in developed countries. Most patients have no obvious symptoms from the primary infection. Studies have indicated that the virus has gradually adapted to the host immune system. Therefore, the control of HCMV infection requires strong immune modulation. With the recent advances in immunotherapy, its application to HCMV infections is receiving increasing attention. Here, we discuss the immune response to HCMV infection, the immune escape mechanism, and the different roles that HCMV plays in various types of immunotherapy, including vaccines, adoptive cell therapy, checkpoint blockade therapy, and targeted antibodies.

Imaging Features of Pulmonary Immune-related Adverse Events

Pulmonary immune-related adverse events represent rare but potentially severe side effects of immunotherapies. Diagnosis is often challenging, as symptoms and imaging features are not specific and may mimic other lung diseases, thus potentially delaying appropriate patient management. In this setting, an accurate imaging evaluation is essential for a prompt detection and correct management of these drug-induced lung diseases. The purpose of this article is to review the different types of pulmonary immune-related adverse events, describe their imaging characteristics on both high-resolution computed tomography and positron emission tomography/computed tomography and stress their underlying diagnostic challenge by presenting the mimickers.

Clinical types of checkpoint inhibitor-related pneumonitis in lung cancer patients: a multicenter experience

Background

Checkpoint inhibitor-related pneumonitis (CIP) is not well classified according to clinical factors. We propose different clinical sub-types of CIP based on clinical factors and investigated the corresponding clinical features, treatments, and outcomes.

Methods

We conducted a multicenter retrospective study of patients with lung cancer (including non-small cell lung cancer and small cell lung cancer) who developed CIP. The clinical characteristics, radiologic features, treatments, and outcomes of CIP were analyzed.

Results

A total of 55 patients developed CIP and were classified into 3 groups as follows: 21 in the pure type (PT) group, 14 in the induced type (IT) group, and 20 in the mixed type (MT) group. The incidence of severe (grade 3–5) pneumonitis was significantly higher in the IT group than in the PT and MT groups (71.4% vs. 14.3% vs. 50.0%, P=0.002). Antiviral therapy was significantly more frequent in the IT group than in the PT and MT groups. Antibiotic therapy was administered in 23.8%, 71.4%, and 80.0% of patients with the PT, IT, and MT, respectively. The improvement time in the PT group was longer than that in the IT and MT groups (0.9 vs. 0.5 vs. 0.3 months, P=0.028). Patients with the PT had a better tumor response to immune checkpoint inhibitors (ICIs) than those with the other 2 types [overall response rate (ORR), 78% vs. 31% vs. 44%, P=0.027].

Conclusions

The clinical classification of CIP may favor strategies for treatments and predict the tumor response to ICIs.