Immune Surveillance of Acute Myeloid Leukemia Is Mediated by HLA-Presented Antigens on Leukemia Progenitor Cells.

Therapy-resistant leukemia stem and progenitor cells (LSC) are a main cause of acute myeloid leukemia (AML) relapse. LSC-targeting therapies may thus improve outcome of patients with AML. Here we demonstrate that LSCs present HLA-restricted antigens that induce T-cell responses allowing for immune surveillance of AML. Using a mass spectrometry-based immunopeptidomics approach, we characterized the antigenic landscape of patient LSCs and identified AML- and AML/LSC-associated HLA-presented antigens absent from normal tissues comprising nonmutated peptides, cryptic neoepitopes, and neoepitopes of common AML driver mutations of NPM1 and IDH2. Functional relevance of shared AML/LSC antigens is illustrated by presence of their cognizant memory T cells in patients. Antigen-specific T-cell recognition and HLA class II immunopeptidome diversity correlated with clinical outcome. Together, these antigens shared among AML and LSCs represent prime targets for T cell-based therapies with potential of eliminating residual LSCs in patients with AML. SIGNIFICANCE: The elimination of therapy-resistant leukemia stem and progenitor cells (LSC) remains a major challenge in the treatment of AML. This study identifies and functionally validates LSC-associated HLA class I and HLA class II-presented antigens, paving the way to the development of LSC-directed T cell-based immunotherapeutic approaches for patients with AML. See related commentary by Ritz, p. 430 . This article is featured in Selected Articles from This Issue, p. 419.

Case Report: Paraneoplastic psoriasis in thymic carcinoma.

Thymic carcinomas are exceedingly rare and very aggressive malignancies of the anterior mediastinum. While thymomas exhibit a high association with paraneoplastic syndromes, these phenomena are a rarity in thymic carcinomas. In general, acanthotic syndromes such as acroceratosis neoplastica and acanthosis nigricans maligna are commonly observed as paraneoplastic phenomena in patients with carcinomas. In contrast, psoriasis vulgaris, another acanthotic disease, rarely occurs as a paraneoplasia. We report the case of a 36-year-old patient with progressive thymic carcinoma (undifferentiated carcinoma, T3N2M1a) and paraneoplastic psoriasis occurring ten months before the initial diagnosis of the carcinoma. Over the course of the disease, new psoriatic flares heralded relapse or progression of the carcinoma. To our knowledge, this is the first reported case of paraneoplastic psoriasis in thymic carcinoma.

[Chemotherapy of malignant tumors]. / Chemotherapie maligner Tumore.

The application of chemotherapy against malignant tumors might control the malignant disease but harbours many pitfalls. The chemotherapy type is chosen depending on the entity and stage of the tumor as well as on the patient's characteristics and fitness. Patients under therapy should be informed on the potential side effects and should be closely monitored by physicians, familiar with the common as well as the substance specific side effects of the drugs used. Preventive or timely application of supportive medication can prevent or diminish drug-induced toxicities. The attending physician has to be aware of the potential treatment-related emergency situations during application as well as several days after. One of the most common and dangerous emergencies that requires immediate medical attention is fever in neutropenia.The use of new medical drug classes, targeted molecular and immune therapies has changed and improved disease control in many tumor entities in a revolutionary manner. Overall, combination treatments including targeted drugs, immunotherapy and/or classical chemotherapy show improved efficacy in tumor control. These novel (combination) therapies may provoke different side effects that physicians need to be familiar with and take into account.

Life-threatening pneumonitis after first-line treatment with osimertinib for primary T790M mutated non-small cell lung cancer.

Epithelial growth factor receptor (EGFR) directed tyrosine kinase inhibitor (TKI) treatment is the standard approach in patients with advanced, EGFR-mutated non-small cell lung cancer (NSCLC). Although benefit/risk ratio is favorable for these TKI and side effects are manageable in the vast majority of patients, severe and even life-threatening side effects have been reported. TKI-induced interstitial lung disease (ILD) has been reported for single cases in modest severity, predominantly in EGFR-TKI pretreated patients. Here, we report a case of successful stabilization of a life-threatening ILD in a de novo T790M mutated NSCLC during first-line treatment with osimertinib. As osimertinib will be used more often in many EGFR-positive NSCLC patients in the future, this potentially life-threatening side effect should receive special attention, especially in first-line treatment.