Severe interstitial pneumonia associated with anti-PD-1 immune checkpoint antibody after talc slurry pleurodesis

The potential role of lung microbiota and lauroylcarnitine in T-cell activation associated with checkpoint inhibitor pneumonitis

BACKGROUND

Checkpoint inhibitor pneumonitis (CIP) is a potentially fatal adverse event characterized by new pulmonary infiltrates in cancer patients receiving immune checkpoint inhibitor therapy. This study aims to explore the interplay between lung microbiota, dysregulated metabolites, and host immunity in CIP.

METHODS

We recruited thirteen hospitalized CIP patients, eleven idiopathic pulmonary fibrosis (IPF) patients, and ten new-onset non-small cell lung cancer patients. Bronchoalveolar lavage fluid samples were collected for 16S rRNA gene sequencing. The percentages of immune cells were determined using manual counting and flow cytometry. Interactions among microbiota, metabolites, and lymphocytes were analyzed using cultured mouse splenocytes and human T cells.

FINDINGS

Proteobacteria emerged as the dominant phylum, notably abundant in both the CIP and IPF groups. Vibrio, Halomonas, Mangrovibacter, and Salinivibrio were the predominant microbiota because of their discriminative abundance patterns. Vibrio (r = 0.72, P-adj = 0.007) and Halomonas (r = 0.65, P-adj = 0.023) demonstrated strong correlations with lymphocytes. Vibrio metschnikovii and Mangrovibacter plantisponsors were more abundant in the CIP group than in the IPF group. Lauroylcarnitine, a key intermediary metabolite co-occurring with the predominant microbiota, exhibited a potent effect on cytokine secretion by mouse and human T cells, notably enhancing IFN-γ and TNF-α production from CD4 and CD8 cells in vitro.

INTERPRETATION

Lauroylcarnitine, co-occurring with the predominant lung microbiota in CIP, could activate T cells in vitro. These findings suggest potential involvement of lung microbiota and acylcarnitine metabolism dysregulation in the pathogenesis of CIP.

FUNDING

This work was supported by Peking University People's Hospital Scientific Research Development Funds (RDJ2022-15) and Provincial Key Clinical Specialty Capacity Building Project 2020 (Department of the Respiratory Medicine).

Early Onset of Severe Interstitial Pneumonitis Associated With Anti-PD-1 Immune Checkpoint Antibody After Pleurodesis

We present a case of lung adenocarcinoma with malignant pleural effusion. Nineteen days after pleurodesis using minocycline and OK-432 (picibanil), pembrolizumab monotherapy was initiated. Four days later, the patient experienced a persistent cough. Chest computed tomography showed that ground-glass opacity appeared on the same side as pleurodesis and spread bilaterally thereafter, which was diagnostic of immune checkpoint inhibitors (ICI)-related pneumonitis. As he presented a severe respiratory failure, corticosteroid therapy was administered. Two weeks later, respiratory failure completely resolved and the abnormal shadows dramatically improved. Our results indicate that severe ICI-related pneumonitis can develop within a short period after pleurodesis.

Metabolic landscape dysregulation in bronchoalveolar lavage fluid of checkpoint inhibitor pneumonitis

BACKGROUND

Checkpoint inhibitor pneumonitis (CIP) is a potentially fatal adverse event resulting from immunotherapy in patients with malignant tumors. However, the pathogenesis of CIP remains poorly understood.

METHODS

We collected bronchoalveolar lavage fluid (BALF) from cohorts of patients with CIP, new-onset lung cancer (LC), and idiopathic pulmonary fibrosis (IPF). Non-targeted metabolomics analysis was conducted to analyze metabolic signatures. Flow cytometry was used to evaluate immune cell subsets.

RESULTS

Lymphocytes were predominant in the BALF of patients with CIP. A total of 903 metabolites were identified, among which lipid compounds were the most abundant. In a comparison between patients with CIP and LC, enrichment analysis of the altered metabolites showed suppressed amino sugar metabolism, and spermidine and spermine biosynthesis in the CIP group. Metabolism of alpha linolenic acid, linoleic acid, and their fatty acid derivatives was enriched in the CIP group relative to the IPF group. The twelve metabolites found to be enriched in the CIP group were positively correlated with the proportion of CD8⁺ T cells. One cluster of BALF metabolites, 57.14% of which were lipid molecules, was inversely correlated with the proportion of natural killer cells.

CONCLUSIONS

In this study, the metabolomic landscape of BALF in patients with CIP was determined. We elucidated suppressed tumor metabolic signatures, enhanced pulmonary inflammatory signaling, and the characteristics of responsible immune cells, which helps to understand the pathogenesis of CIP.

Unusual Diffuse Ground-Glass Opacities in the Lungs on 18F-FDG PET/CT: A Case of Melanoma With Pulmonary Metastasis

ABSTRACT

A 61-year-old man was diagnosed with a malignant melanoma and underwent a resection; he presented with progressive dyspnea after treatment with interferon for 2 months. 18F-FDG PET/CT scan revealed diffuse ground-glass opacities (GGOs) in both lungs with mildly elevated 18F-FDG uptake, similar to that observed with interstitial inflammation. However, a lung biopsy confirmed that the diffuse GGOs were pulmonary metastases of melanoma and were positive for the BRAF mutation. The diffuse GGOs and the progressive dyspnea disappeared after BRAF-targeted therapy. This represents an unusual case of lung metastases from melanoma, mistakenly interpreted as lung inflammation induced by immunotherapy.

Pulmonary Toxicities Associated With the Use of Immune Checkpoint Inhibitors: An Update From the Immuno-Oncology Subgroup of the Neutropenia, Infection & Myelosuppression Study Group of the Multinational Association for Supportive Care in Cancer

The development of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, with agents such as nivolumab, pembrolizumab, and cemiplimab targeting programmed cell death protein-1 (PD-1) and durvalumab, avelumab, and atezolizumab targeting PD-ligand 1 (PD-L1). Ipilimumab targets cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). These inhibitors have shown remarkable efficacy in melanoma, lung cancer, urothelial cancer, and a variety of solid tumors, either as single agents or in combination with other anticancer modalities. Additional indications are continuing to evolve. Checkpoint inhibitors are associated with less toxicity when compared to chemotherapy. These agents enhance the antitumor immune response and produce side- effects known as immune-related adverse events (irAEs). Although the incidence of immune checkpoint inhibitor pneumonitis (ICI-Pneumonitis) is relatively low, this complication is likely to cause the delay or cessation of immunotherapy and, in severe cases, may be associated with treatment-related mortality. The primary mechanism of ICI-Pneumonitis remains unclear, but it is believed to be associated with the immune dysregulation caused by ICIs. The development of irAEs may be related to increased T cell activity against cross-antigens expressed in tumor and normal tissues. Treatment with ICIs is associated with an increased number of activated alveolar T cells and reduced activity of the anti-inflammatory Treg phenotype, leading to dysregulation of T cell activity. This review discusses the pathogenesis of alveolar pneumonitis and the incidence, diagnosis, and clinical management of pulmonary toxicity, as well as the pulmonary complications of ICIs, either as monotherapy or in combination with other anticancer modalities, such as thoracic radiotherapy.

Successful Re-administration of Atezolizumab for a Non-small-cell Lung Cancer Patient after Cardiac Tamponade Development as a Manifestation of Pseudo-progression Induced by Combination Treatment with Atezolizumab and Cytotoxic Chemotherapy

Pseudo-progression is a phenomenon induced by treatment with immune checkpoint inhibitors and is characterized by an increase in tumor size or the appearance of new lesions, followed by tumor regression. However, life-threatening conditions, such as cardiac tamponade, can develop in such patients. We herein report on a 69-year-old man with lung adenocarcinoma who developed cardiac tamponade as a manifestation of pseudo-progression induced by treatment with atezolizumab combined with cytotoxic chemotherapy. After managing the cardiac tamponade, atezolizumab was successfully re-administered along with cytotoxic chemotherapy without disease progression.