Peikert, Tobias

Metastatic CUP is complex, especially NCUP. Precision oncology is crucial for rare, aggressive cancers. A 54-year-old had HER2+ neuroendocrine carcinoma of unknown origin. T-DXd treatment, response, re-challenge show importance of genomics and caution.

TB remains a leading cause of morbidity and mortality worldwide. However, most infected immunocompetent individuals are asymptomatic and only 5–10% of these will eventually develop active TB during their lifetime (typically within 2 years after exposure). Therefore, rapid diagnosis and efficient management of asymptomatic infected individuals who are at the highest risk of progression and transmission remain major clinical and public health challenges. In recent years, there has been important scientific progress in our understanding of the spectrum of asymptomatic Mycobacterium tuberculosis (Mtb) infections that not only includes the dynamic state of latent TB infection (LTBI), but also the preclinical state of incipient and subclinical TB. The latter is possibly as prevalent as symptomatically active TB and potentially contributes to global Mtb transmission in various settings. We summarize the latest developments and current challenges of the existing testing tools for LTBI and describe promising biomarkers and diagnostics for the spectrum of asymptomatic TB. Following the negative results of a recent clinical trial for a biomarker-guided preventive therapy approach, we also suggest some treatment options for incipient TB.

Background Immune checkpoint inhibitors (ICIs) are now a first-line treatment option for patients with pleural mesothelioma with the recent approval of ipilimumab and nivolumab. Mesothelioma has a low tumor mutation burden and no robust predictors of survival with ICI. Since ICIs enable adaptive antitumor immune responses, we investigated T-cell receptor (TCR) associations with survival in participants from two clinical trials treated with ICI. Methods We included patients with pleural mesothelioma who were treated with nivolumab (NivoMes, NCT02497508) or nivolumab and ipilimumab (INITIATE, NCT03048474) after first-line therapy. TCR sequencing was performed with the ImmunoSEQ assay in 49 and 39 pretreatment and post-treatment patient peripheral blood mononuclear cell (PBMC) samples. These data were integrated with TCR sequences found in bulk RNAseq data by TRUST4 program in 45 and 35 pretreatment and post-treatment tumor biopsy samples and TCR sequences from over 600 healthy controls. The TCR sequences were clustered into groups of shared antigen specificity using GIANA. Associations of TCR clusters with overall survival were determined by cox proportional hazard analysis. Results We identified 4.2 million and 12 thousand complementarity-determining region 3 (CDR3) sequences from PBMCs and tumors, respectively, in patients treated with ICI. These CDR3 sequences were integrated with 2.1 million publically available CDR3 sequences from healthy controls and clustered. ICI-enhanced T-cell infiltration and expanded T cell diversity in tumors. Cases with TCR clones in the top tertile in the pretreatment tissue or in circulation had significantly better survival than the bottom two tertiles (p<0.04). Furthermore, a high number of shared TCR clones between pretreatment tissue and in circulation was associated with improved survival (p=0.01). To potentially select antitumor clusters, we filtered for clusters that were (1) not found in healthy controls, (2) recurrent in multiple patients with mesothelioma, and (3) more prevalent in post-treatment than pretreatment samples. The detection of two-specific TCR clusters provided significant survival benefit compared with detection of 1 cluster (HR<0.001, p=0.026) or the detection of no TCR clusters (HR=0.10, p=0.002). These two clusters were not found in bulk tissue RNA-seq data and have not been reported in public CDR3 databases. Conclusions We identified two unique TCR clusters that were associated with survival on treatment with ICI in patients with pleural mesothelioma. These clusters may enable approaches for antigen discovery and inform future targets for design of adoptive T cell therapies.

Abstract Introduction: While CT lung cancer screening reduces lung cancer-specific mortality, there are remaining challenges. Radiomic tools promiss to address these challenges, however, they are subject to interobserver variability if semi-automated segmentation techniques are used. Herein we report interobserver variability for two validated radiomic tools, BRODERS (Benign versus aggRessive nODule Evaluation using Radiomic Stratification) and CANARY (Computer-Aided Nodule Assessment and Risk Yield). Methods We retrospectively analyzed the CT images of 95 malignant lung nodules of the adenocarcinoma spectrum using BRODERS and CANARY. Cases were identified at Mayo Clinic (n = 45) and Vanderbilt University Medical Center and Nashville/Veteran Administration Tennessee Valley Health Care System (n = 50). Three observers with different training levels (medical student, internal medicine resident and thoracic radiology fellow) each performed lung nodule segmentation. All methods were carried out in accordance with relevant guidelines and regulations Results Interclass correlation coefficients (ICC) of 0.77, 0.98 and 0.97 for the average nodule volume, BRODERS cancer probability and Score Indicative of Lesion Aggression (SILA) which summarizes the distribution of the CANARY exemplars indicated good to excellent reliability, respectively. The dice similarity coefficient was 0.79 and 0.81 for the data sets from the two institutions. Conclusion: BRODERS and CANARY are robust radiomics tools with excellent interobserver variability. These tools are simple and reliable regardless the observer/operator’s level of training.

Abstract Rationale Candida albicans (CA) is ubiquitous and individuals are often immunized against it. However, skin testing reactivity with CA-antigens (CAAg) have been variable during latent tuberculosis infection (LTBI) screening. We hypothesized that the use of a CAAg in an ELISPOT assay would provide a positive control to study tuberculosis (TB)-antigen specific immune responses. Objective To test an ELISPOT with TB-antigens and control conditions, including a purified protein derivative of CA, CAAg, that differentiates subjects with LTBI from unexposed subjects. Methods An ELISPOT that detects interferon-γ from PBMCs (2×105 cells) after 2-day incubation with TB antigens, controls, including CAAg, and co-stimulatory antibodies. We studied two independent cohorts of subjects with LTBI diagnosis based on TST and IGRA results per clinical guidelines. Results One-hundred thirty-nine subjects were studied in 2010–12, including 27 patients with LTBI and 21 IGRA(−) unexposed subjects. ELISPOT with TB-antigens but also CAAg - nil (78 [21 – 182] vs. 9 [1 – 50] cfu) differentiated LTBI subjects from unexposed ones (P&lt;0.005). A second cohort of 76 subjects were studied in 2015–17, including 14 patients with LTBI and 24 unexposed controls, which showed similar statistical results. Positive control (SEAB/antiCD3) did not differentiate these study groups. ELISPOT results with CAAg correlated with results of ELISPOT with TB antigens in all subjects (P&lt;0.001), and in the LTBI and unexposed groups independently. Conclusion An ELISPOT assay that includes CAAg revealed immune reactivity that is prevalent in LTBI. The immune subsets that react to both CA and mycobacterial antigens are unclear, but may be relevant for both TB and candida immunity.

Abstract Background Acute respiratory exacerbations in idiopathic pulmonary fibrosis (IPF), often triggered by infection, are life threatening events characterized by rapid deterioration of lung function and associated with poor prognosis. Since microbial antigens modulate immunity by activating different pattern recognition receptors (PRR) expressed by innate immune cells (including B-cells), we sought to investigate how the activation of human B-cells through PRR stimulation by different microbial (CpG and β-glucan) and non-microbial (Mitochondrial DAMPs; MTDs) antigens resulted in the release of an inflammatory/fibrotic milieu that contributed to the pathogenesis of fibrosis in patients with IPF. Results Our results show that an inflammatory milieu is induced by stimulating circulating B-cells with both noninfectious (MTDs) and infectious antigens (CpG and β-glucan) commonly found in bacteria and fungi. Moreover, we show that the inflammatory milieu produced was specific to the inducing antigen, and that the microbial antigens (CpG and β-glucan) triggered distinct signaling pathways in B-cells. Specifically, CpG induced mTOR-activation while β-glucan was mTOR-independent and activated Src and p38. Furthermore, our results also show that B-cell aggregates are present within fibrotic areas of the lung in IPF patients and activated B-cells induce fibroblast migration, which was modified by antifibrotics (nintedanib and pirfenidone). Conclusion Our results highlight the potential contribution of activated B-cells through PRRs to the proinflammatory and profibrotic milieu seen in patients with idiopathic pulmonary fibrosis.

Abstract We hypothesize that B-lymphocytes are conducive to the pathogenesis of idiopathic pulmonary fibrosis (IPF), a progressive and fatal interstitial lung disease. B-lymphocytes aggregate in the lungs of IPF patients to form tertiary lymphoid follicles. How these follicles are formed and their role in the pathogenesis of IPF is not known. Hence, we sought to characterize how the activation of B-lymphocytes from IPF patients may contribute to the disease. Methods IPF patients defined by ATS guidelines were identified and recruited under local IRB #14-004714. B-lymphocytes were then isolated by negative selection. Cytokines and immunoglobulins from plasma or B-lymphocyte supernatants were measured by ELISA and signaling pathways were elucidated from whole-cell lysates by immunoblotting. Our results show that B-lymphocyte aggregates are present within fibrotic areas of the lung of IPF patients and that activated B-lymphocytes induce fibroblast migration. This effect was abrogated by nintedanib inhibition of B-lymphocyte activation. Furthermore, microbial antigen (β-glucan and CpG) activation of B-lymphocytes through pattern recognition receptors (PRRs; TLR9 and Dectin-1) contributed to the proinflammatory and profibrotic milieu seen in IPF patients. Stimulation of TLR9 and Dectin-1 resulted in activation of mTOR-dependent and -independent pathways, respectively. Rapamycin decreased TLR9 signaling, but not Dectin-1 mediated pathways. Nintedanib abrogated B-cell activation, IgM production, and the profibrotic milieu by interfering with both the mTOR-dependent and -independent pathways. In conclusion, our findings implicate activated B-lymphocytes in IPF pathogenesis highlighting the role of PRRs in this disease.

ObjectiveAutoreactive B cells are responsible for antineutrophil cytoplasmic antibody (ANCA) production in ANCA‐associated vasculitis (AAV). Rituximab (RTX) depletes circulating B cells, including autoreactive B cells. We aimed to evaluate changes and associations with relapse of the circulating autoreactive B cell pool following therapeutic B cell depletion in AAV.MethodsSequential flow cytometry was performed on 148 samples of peripheral blood mononuclear cells from 23 patients with proteinase 3 (PR3)–ANCA–positive AAV who were treated with RTX for remission induction and monitored after stopping therapy during long‐term follow‐up in a prospective clinical trial. PR3 was used as a ligand to target autoreactive PR3‐specific (PR3+) B cells. B cell recurrence was considered as the first blood sample with ≥10 B cells/μl after RTX treatment.ResultsAt B cell recurrence, PR3+ B cell frequency among B cells was higher than baseline (P < 0.01). Within both PR3+ and total B cells, frequencies of transitional and naive subsets were higher at B cell recurrence than at baseline, while memory subsets were lower (P < 0.001 for all comparisons). At B cell recurrence, frequencies of B cells and subsets did not differ between patients who experienced relapse and patients who remained in remission. In contrast, the plasmablast frequency within the PR3+ B cell pool was higher in patients who experienced relapse and associated with a shorter time to relapse. Frequencies of PR3+ plasmablasts higher than baseline were more likely to be found in patients who experienced relapse within the following 12 months compared to those in sustained remission (P < 0.05).ConclusionThe composition of the autoreactive B cell pool varies significantly following RTX treatment in AAV, and early plasmablast enrichment within the autoreactive pool is associated with future relapses.