Analysis of cytokines in serum and bronchoalveolar lavage fluid in patients with immune-checkpoint inhibitor-associated pneumonitis: a cross-sectional case-control study.

PURPOSE: Immune-checkpoint inhibitors (ICI) present a new treatment for malignancies by boosting the immune system. This has led to a variety of immune-related adverse events, including ICI-associated pneumonitis (ICIaP). Diagnosis thereof is often challenging, and its pathogenesis has not yet been fully understood. The aim of this cross-sectional case-control study was to investigate cytokines in serum and bronchoalveolar lavage fluid (BALF) expressed in patients with ICIaP compared to controls consisting of healthy individuals, patients with lung cancer and patients with interstitial lung diseases (ILD) other than ICIaP. METHODS: From January 2018 until June 2019, 401 adult patients with various lung diseases were prospectively enrolled in a BALF- and serum biobank, called BALOTHEK. Of these, 12 patients were diagnosed with ICIaP (Pembrolizumab, Ipilimumab, or both, and Durvalumab) serving as case group. Subjects with one of three diagnosis groups from BALOTHEK, including lung cancer, ILD other than ICIaP, and healthy individuals, served as matched controls. The following 11 cytokines were simultaneously analyzed in BALF and serum of each study participant: interferon gamma, tumor necrosis factor alpha, interleukin (IL) 1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-12p70, IL-13 and IL-17A. This study was approved by the local ethic review committee (BASEC-ID 2017-02,307 and 2018-01,724). RESULTS: Absolute number and percentage of lymphocytes in BALF of patients with ICIaP were significantly higher compared to control groups. For the investigated cytokines in BALF, a significant increase of IL-6 level was shown for patients with ICIaP compared to control groups (p = 0.031, adjusted for multiple comparisons). CONCLUSION: Cytokine profile assessed in BALF shows promising potential for facilitating diagnosis and understanding of pathophysiology of ICIaP. IL-6 may not only contribute to better understanding of pathophysiology but also herald therapeutic implications for Tocilizumab.

Evaluation of cytokines in the tumor microenvironment of lung cancer using bronchoalveolar lavage fluid analysis.

INTRODUCTION: Lung cancer is the leading cause of death by cancer. In recent years, immunotherapy with checkpoint inhibitors (ICI) emerged as a promising new therapeutic approach. However, a deeper understanding of the immunologic responses adjacent to the tumor known as tumor microenvironment (TME) is needed. Our study investigated TME of lung cancer by analyzing cytokines in bronchoalveolar lavage fluid (BALF). MATERIALS AND METHODS: Between January 2018 and June 2019, 119 patients were prospectively enrolled in this study. For each cancer patient, levels of 16 cytokines (fractalkine, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukins (IL): IL-1b, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17A, and IL-23) were measured in BALF and serum and compared to healthy individuals and patients with other lung diseases. RESULTS: There were several significant differences of cytokine levels of patients with lung cancer compared to healthy individuals. However, none of them remained in the multivariate analysis compared to other lung diseases in either BALF or serum. Furthermore, there were no significant differences between the groups in cell differentiation of either BALF or serum. Cytokine levels in BALF were generally near the lower detection limit and showed almost no correlation with their respective levels measured in serum of the same individual. CONCLUSIONS: Cytokines in BALF and serum of lung cancer patients may indicate unspecific inflammation. BAL is not recommendable as a tool to investigate TME of lung cancer. Therefore, cytokines measured in BALF are probably not appropriate as predictors in patients treated with ICIs.

Ipilimumab and early signs of pulmonary toxicity in patients with metastastic melanoma: a prospective observational study.

Ipilimumab, an immune checkpoint inhibitor, is approved for treatment metastastic melanoma and is a promising agent against other malignancies. There is some preliminary evidence from case reports that ipilimumab treatment may be associated with pulmonary side effects. However, data from prospective studies on ipilimumab-related pulmonary toxicity are still scarce. Serial spirometries and measurements of CO-diffusion capacity (DLCO) in patients with metastatic melanoma before and during treatment with ipilimumab were performed. A reduction from baseline of forced vital capacity (FVC) of ≥ 10%, or ≥ 15% of DLCO was defined as clinically meaningful and indicative for pulmonary toxicity. Of 71 patients included in this study, a clinically meaningful lung function decline was registered in 6/65 (9%), 5/44 (11%), and 9/38 (24%) patients after 3, 6, and 9 weeks of treatment initiation, respectively. Even after adjusting for age, concomitant melanoma treatment, progressive pulmonary metastases, and baseline pulmonary function values, mean ± SD DLCO decreased significantly during follow-up (-4.3% ± 13.6% from baseline, p = 0.033). Only 7% of patients reported respiratory symptoms. Clinically manifest ipilimumab-related pneumonitis was diagnosed only in one patient (1.4%). DLCO decline maybe an early indicator of subclinical pulmonary drug toxicity. Therefore, routine pulmonary function testing including DLCO measurement during treatment might help for risk stratification to screen for ipilimumab-related pneumonitis.