Thymic Imaging Pitfalls and Strategies for Optimized Diagnosis.

Thymic imaging is challenging because the imaging appearance of a variety of benign and malignant thymic conditions are similar. CT is the most commonly used modality for mediastinal imaging, while MRI and fluorine 18 fluorodeoxyglucose (FDG) PET/CT are helpful when they are tailored to the correct indication. Each of these imaging modalities has limitations and technical pitfalls that may lead to an incorrect diagnosis and mismanagement. CT may not be sufficient for the characterization of cystic thymic processes and differentiation between thymic hyperplasia and thymic tumors. MRI can be used to overcome these limitations but is subject to other potential pitfalls such as an equivocal decrease in signal intensity at chemical shift imaging, size limitations, unusual signal intensity for cysts, subtraction artifacts, pseudonodularity on T2-weighted MR images, early imaging misinterpretation, flow and spatial resolution issues hampering assessment of local invasion, and the overlap of apparent diffusion coefficients between malignant and benign thymic entities. FDG PET/CT is not routinely indicated due to some overlap in FDG uptake between thymomas and benign thymic processes. However, it is useful for staging and follow-up of aggressive tumors (eg, thymic carcinoma), particularly for detection of occult metastatic disease. Pitfalls in imaging after treatment of thymic malignancies relate to technical challenges such as postthymectomy sternotomy streak metal artifacts, differentiation of postsurgical thymic bed changes from tumor recurrence, or human error with typical "blind spots" for identification of metastatic disease. Understanding these pitfalls enables appropriate selection of imaging modalities, improves diagnostic accuracy, and guides patient treatment. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Effects of EGFR driver mutations on pathologic regression in resectable locally advanced non-small cell lung cancer treated with neoadjuvant chemoradiation and completion surgery.

OBJECTIVE: We hypothesized that driver mutations in epidermal growth factor receptor (EGFR) are associated with decreased pathologic response to neoadjuvant chemoradiation (NA-ChRT) in locally advanced non-small cell lung cancer (LA-NSCLC). METHODS: Patients with Stage IIB-IIIA NSCLC treated with NA-ChRT, completion surgery, and underwent molecular profile testing were identified in a lung cancer database. Pathologic response was quantified using: (i) major pathologic response (MPR), (ii) complete pathologic response (pCR), and (iii) mean residual viable tumor cells (MRTC). Two groups were formed based on the presence or absence of driver mutations. Clinical and pathological correlations between the groups were studied. RESULTS: Forty-seven patients underwent tumor molecular profile testing, NA-ChRT, and completion surgery. Compared to the no-driver mutation group, the driver mutation group had lower MPR (23% vs 71%, p = 0.003), pCR (0% vs 26%, p = 0.02), and higher MRTC (43.4% vs 15.8%, p = 0.009). Univariate analysis showed an increased MPR rate for smokers, squamous cell histology, ChRT-surgery interval >65 days, and no-driver mutations. Multivariate analysis showed that only no-driver mutations (OR 0.39, p = 0.02) remained significant for MPR. PD-L1 status did not affect MPR. At 2 years, the driver mutation group had lower rates of local control (Hazard ration [HR] 0.67, p = 0.17) and disease-free survival (HR 0.5, p = 0.001). Overall survival was similar for both groups (HR = 1.04, p = 0.86). CONCLUSION: Following 60 Gray NA-ChRT, tumors with a driver mutation had lower MPR and pCR rates than tumors without a driver mutation. PD-L1 was not associated with tumor regression. ADVANCES IN KNOWLEDGE: Patients with resectable LA-NSCLC and an EGFR driver mutation treated with neoadjuvant-ChRT and completion surgery have reduced pathologic regression, lower local control rates, and shorter disease-free survival than patients without a driver mutation. Evaluation of molecular testing should be introduced in LA-NSCLC intended for prognostication and treatment decisions.

Effect of pharmacological heart failure drugs and gene therapy on Danon's cardiomyopathy.

Danon disease is a rare X-linked genetic disease resulting from LAMP2 mutations leading to defective lysosomal function. Heart failure is the main causes of morbidity and mortality. Mice with an LAMP2-exon-6-deletion (L2Δ6), develop cardiac hypertrophy followed by dilated cardiomyopathy, in association with accumulation of autophagosomes, fibrosis and oxidative stress. We investigated the effect of drugs used to treat heart failure and of LAMP2 gene therapy on the phenotype, molecular markers and ROS in LAMP2 cardiomyopathy. L2Δ6 mice were treated with Angiotensin II, Ramipril, Metoprolol or Spironolactone. Gene therapy was delivered by IP injection of Adeno-associated-virus (AAV9) -LAMP2 vector to neonates ("AAVLAMP2-Prevention"), or at 15 weeks of age ("AAVLAMP2-Treatment"). Angiotensin II markedly aggravated the cardiac phenotype. Ramipril and Spironolactone were effective in attenuating left ventricular hypertrophy and preserving the systolic function. Cardiac protection was associated with decreased autophagosome accumulation, reduced fibrosis and oxidative stress. Gene therapy effectively attenuated autophagosome accumulation and ROS in L2Δ6 hearts, lowering troponin release to nearly normal levels. AAVLAMP2-Prevention protected against systolic dysfunction and decreased hypertrophy. AAVLAMP2-Treatment prevented ventricular dilatation and dysfunction but had no effect on wall thickness. We conclude that RAAS inhibitors are highly effective against cardiomyopathy progression in an experimental mouse model of Danon's and shall be considered in human patients for this purpose until novel therapies become clinically available.

Direct identification of ALK and ROS1 fusions in non-small cell lung cancer from hematoxylin and eosin-stained slides using deep learning algorithms.

Anaplastic lymphoma kinase (ALK) and ROS oncogene 1 (ROS1) gene fusions are well-established key players in non-small cell lung cancer (NSCLC). Although their frequency is relatively low, their detection is important for patient care and guides therapeutic decisions. The accepted methods used for their detection are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assay, as well as DNA and RNA-based sequencing methodologies. These assays are expensive, time-consuming, and require technical expertise and specialized equipment as well as biological specimens that are not always available. Here we present an alternative detection method using a computer vision deep learning approach. An advanced convolutional neural network (CNN) was used to generate classifier models to detect ALK and ROS1-fusions directly from scanned hematoxylin and eosin (H&E) whole slide images prepared from NSCLC tumors of patients. A two-step training approach was applied, with an initial unsupervised training step performed on a pan-cancer sample cohort followed by a semi-supervised fine-tuning step, which supported the development of a classifier with performances equal to those accepted for diagnostic tests. Validation of the ALK/ROS1 classifier on a cohort of 72 lung cancer cases who underwent ALK and ROS1-fusion testing at the pathology department at Sheba Medical Center displayed sensitivities of 100% for both genes (six ALK-positive and two ROS1-positive cases) and specificities of 100% and 98.6% respectively for ALK and ROS1, with only one false-positive result for ROS1-alteration. These results demonstrate the potential advantages that machine learning solutions may have in the molecular pathology domain, by allowing fast, standardized, accurate, and robust biomarker detection overcoming many limitations encountered when using current techniques. The integration of such novel solutions into the routine pathology workflow can support and improve the current clinical pipeline.

Pleuritis due to Mycobacterium xenopi without pulmonary infection.

Nontuberculous mycobacteria (NTM) may cause pulmonary and extra-pulmonary disease in both immunocompetent and immunocompromised patients. Pleuritis is an uncommon manifestation on NTM disease, and pleuritis caused by Mycobacterium xenopi has only been described once before. Because it is considered to be an environmental contaminant, isolation of M. xenopi from bronchopulmonary secretions or other sites is often dismissed. The disease caused by M. xenopi is usually a pulmonary infection and typically occurs in severely immunocompromised individuals or in immunocompetent patients with an underlying chronic lung disease. We describe an unusual case of pleuritis caused by M. xenopi in a patient without an underlying chronic lung disease and with no evidence of a concurrent M. xenopi pulmonary infection.

Soluble HLA peptidome of pleural effusions is a valuable source for tumor antigens.

BACKGROUND: Soluble human leucocyte antigen (sHLA) molecules, released into the plasma, carry their original peptide cargo and provide insight into the protein synthesis and degradation schemes of their source cells and tissues. Other body fluids, such as pleural effusions, may also contain sHLA-peptide complexes, and can potentially serve as a source of tumor antigens since these fluids are drained from the tumor microenvironment. We explored this possibility by developing a methodology for purifying and analyzing large pleural effusion sHLA class I peptidomes of patients with malignancies or benign diseases. METHODS: Cleared pleural fluids, cell pellets present in the pleural effusions, and the primary tumor cells cultured from cancer patients' effusions, were used for immunoaffinity purification of the HLA molecules. The recovered HLA peptides were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and the resulting LC-MS/MS data were analyzed with the MaxQuant software tool. Selected tumor antigen peptides were tested for their immunogenicity potential with donor peripheral blood mononuclear cells (PBMCs) in an in vitro assay. RESULTS: Mass spectrometry analysis of the pleural effusions revealed 39,669 peptides attributable to 11,305 source proteins. The majority of peptides identified from the pleural effusions were defined as HLA ligands that fit the patients' HLA consensus sequence motifs. The membranal and soluble HLA peptidomes of each individual patient correlated to each other. Additionally, soluble HLA peptidomes from the same patient, obtained at different visits to the clinic, were highly similar. Compared with benign effusions, the soluble HLA peptidomes of malignant pleural effusions were larger and included HLA peptides derived from known tumor-associated antigens, including cancer/testis antigens, lung-related proteins, and vascular endothelial growth factor pathway proteins. Selected tumor-associated antigens that were identified by the immunopeptidomics were able to successfully prime CD8+ T cells. CONCLUSIONS: Pleural effusions contain sHLA-peptide complexes, and the pleural effusion HLA peptidome of patients with malignant tumors can serve as a rich source of biomarkers for tumor diagnosis and potential candidates for personalized immunotherapy.

Mesencephalic astrocyte-derived neurotrophic factor is secreted from interferon-γ-activated tumor cells through ER calcium depletion.

The most successful immunotherapeutic agents are blocking antibodies to either programmed cell death-1 (PD-1), an inhibitory receptor expressed on T lymphocytes, or to its ligand, programmed cell death-ligand 1 (PD-L1). Nevertheless, many patients do not respond, and additional approaches, specifically blocking other inhibitory receptors on T cells, are being explored. Importantly, the source of the ligands for these receptors are often the tumor cells. Indeed, cancer cells express high levels of PD-L1 upon stimulation with interferon-γ (IFN-γ), a major cytokine in the tumor microenvironment. The increase in PD-L1 expression serves as a negative feedback towards the immune system, and allows the tumor to evade the attack of immune cells. A potential novel immunoregulator is mesencephalic astrocyte-derived neurotrophic factor (MANF), an endoplasmic reticulum (ER)-resident protein that is secreted from pancreatic beta cells upon cytokines activation, and can induce an alternatively activated macrophage phenotype (M2), and thus may support tumor growth. While MANF was shown to be secreted from pancreatic beta cells, its IFN-γ-induced secretion from tumor cells has never been assessed. Here we found that IFN-γ induced MANF secretion from diverse tumor cell-lines-melanoma cells, colon carcinoma cells and hepatoma cells. Mechanistically, there was no increase in MANF RNA or intracellular protein levels upon IFN-γ stimulation. However, IFN-γ induced ER calcium depletion, which was necessary for MANF secretion, as Dantrolene, an inhibitor of ER calcium release, prevented its secretion. Thus, MANF is secreted from IFN-γ-stimulated tumor cells, and further studies are required to assess its potential as a drug target for cancer immunotherapy.

Immunotherapy response modeling by ex-vivo organ culture for lung cancer.

One of the major hurdles for the advancement of cancer immunotherapy is lack of robust, accessible experimental models. We aimed to produce an ex-vivo organ culture (EVOC) model of immunotherapy for non-small cell lung cancer (NSCLC). Freshly resected early stage tumors were collected from the operating room, fragmented to clusters < 450 µm and cultured with fetal calf serum and human autologous serum. The resulting EVOC includes cancer epithelial cells within tumor tissue clusters and immune cells. Original tissue features are reflected in the EVOCs. The response to immune checkpoint inhibitors (ICI) was assessed by IFNγ gene induction. Interestingly, IFNγ EVOC induction was numerically higher when anti-CTLA4 was added to anti-PD-L1 treatment, supporting the notion that anti-CTLA4 impacts cancer partly through tumor-resident immune cells. In parallel, immunohistochemistry (IHC) for key immune-related proteins was performed on the formalin-fixed paraffin embedded (FFPE) corresponding tumors. EVOC IFNγ induction by ICI correlated with basal non-induced IFNγ, CD8, CD4 and FOXP3 mRNA levels within EVOCs and with tumor-FFPE-IHC for CD8 and granzyme B. A weaker correlation was seen with tumor-FFPE-IHC for CD3, CD4, CD68, FOXP3 and tumor-PD-L1. Tertiary lymphoid structure density was also correlated with the ICI response. Our study provides novel data about biomarkers that correlate with ICI-induced response of early stage NSCLC. Retention of the microenvironment and minimal addition of exogenous factors suggest this model to reliably represent the original tumor. The cluster-based EVOC model we describe can provide a valuable, yet simple and widely applicable tool for the study of immunotherapy in NSCLC.

Reduction in Filamin C transcript is associated with arrhythmogenic cardiomyopathy in Ashkenazi Jews.

BACKGROUND: Filamin C is a cytoskeletal protein expressed in cardiac cells. Nonsense variations in the filamin C gene (FLNC) were associated with dilated and arrhythmogenic cardiomyopathies. METHODS AND RESULTS: We identified an intronic variation in FLNC gene (c.3791-1G > C) in three unrelated Ashkenazi Jewish families with variable expression of arrhythmia and cardiomyopathy. cDNA was prepared from a mutation carrier's cultured skin fibroblasts. Quantitative PCR demonstrated a reduction in total FLNC transcript, and no other FLNC splice variants were found. Single-nucleotide polymorphism (SNP) analysis revealed heterozygous variations in the genomic DNA that were not expressed in the messenger RNA. Immunohistochemical analysis of cardiac sections detected a normal distribution of filamin C protein in the heart ventricles. CONCLUSION: The transcript that included the FLNC variant was degraded. Haploinsufficiency in filamin C underlies arrhythmogenic cardiomyopathy with variable symptoms.

MiR-21, EGFR and PTEN in non-small cell lung cancer: an in situ hybridisation and immunohistochemistry study.

AIMS: To analyse microRNA (miR)-21 distribution and expression at the cellular level in non-small cell lung cancer (NSCLC). MiR-21 is an oncogenic microRNA overexpressed in NSCLC. In previous studies, overexpression of miR-21 was evaluated from the tumour bulk by quantitative reverse transcription PCR with results expressed on average across the entire cell population. METHODS: We used in situ hybridisation and immunohistochemistry to assess the correlation between miR-21 levels and the expression of markers that may be possible targets (epidermal growth factor reaction) or may be involved in its upregulation (phosphatase and tensin homolog (PTEN), p53). The Pearson's χ2 tests was used to assess correlation with clinicopathological data and with miR-21 expression both in tumour and tumour stroma. RESULTS: Cytoplasmic staining and expression of Mir-21 were detected in the tumours and in associated stromal cells. Expression was highest in the stroma immediately surrounding the tumour cells and decreased as the distance from the tumour increased. No expression of miR-21 was found in normal lung parenchyma and a significant association was found between tumour localised miR-21 and PTEN. CONCLUSIONS: Presence of miR-21 in both cell tumour and stromal compartments of NSCLC and the relationship with PTEN confirms miR-21 as a microenvironment signalling molecule, possibly inducing epithelial mesenchymal transition and invasion by targeting PTEN in the stromal compartment possibly through exosomal transport. In situ immunohistochemical studies such as ours may help shed light on the complex interactions between miRNAs and its role in NSCLC biology.

Transformation to small cell lung cancer as a mechanism of resistance to immunotherapy in non-small cell lung cancer.

OBJECTIVES: Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death world-wide. Immune checkpoint inhibitors (ICI) have become the most promising type of treatment in oncology in general, and significantly so in NSCLC. Limited data is available about mechanisms of primary resistance. Data is lacking about mechanisms involved in acquired resistance or mixed responses in NSCLC. We aimed to identify mechanisms of resistance by studying biopsies taken from sites of secondary progression. MATERIALS AND METHODS: We identified all cases of NSCLC that have received ICI for advanced disease in our institute. Of these cases, those that have demonstrated acquired resistance or mixed responses, and have underwent a biopsy from a progressive lesion were analyzed. Selected specimens were subjected to next-generation sequencing (NGS; Oncomine™ Solid Tumour Fusion Transcript Kit). RESULTS: Out of 664 lung cancer cases, 249 were NSCLC that have received ICI. Of these, eight cases matched our search criteria. Two of them demonstrated transformation to small cell lung cancer (SCLC; 2/8, 25%). NGS verified a common origin to a matched pre-treatment NSCLC specimen and an on-treatment progressive SCLC specimen. In two cases no tumor cells were found and in the remaining four the pathology was similar to the initial biopsy. In one of the cases of SCLC transformation platinum-etoposide chemotherapy was administered, with short-term benefit only and further disease progression. CONCLUSION: Mechanisms of acquired resistance to ICI include SCLC transformation. Repeat biopsies of progressing lesions after initial response or in cases of mixed response can shed light on mechanisms of resistance.

Magnetic Resonance Imaging for the Follow-up of Treated Thymic Epithelial Malignancies.

PURPOSE: The purpose of this article was to compare magnetic resonance imaging (MRI) depiction of thymic malignancy progression/recurrence with that of computed tomography (CT). METHODS: We retrospectively reviewed all surgically treated thymic epithelial malignancy (TEM) patients between 2011 and 2018 who were followed-up with chest CT and MRI. We compared the detection of recurrence and metastatic disease between the CT and MRI scans in each of these patients. RESULTS: Of 187 patients treated in our institution for TEM, 22 were followed-up with both CT and MRI. TNM stage at diagnosis was as follows: I (n=14), II (n=1), IIIa (n=4), IIIb (n=2), IVa (n=1), and IVb (n=0). Patients were followed-up for a mean of 6.2 years, range 0.7 to 17.7 years. The mean interval between CT and MRI was 5.4 (range, 1 to 15) months. Most patients had no recurrence (n=16), 4 had recurrence after R0 or R1 resection, 1 had stable disease, and 1 had progression of disease after R2 resection. CT and MRI performed equally in the identification of pleural spread (n=5), lymphadenopathy (n=4), and pulmonary metastases (n=1). Retrosternal recurrence (n=1) was identified by MRI despite sternotomy wire artifacts. MRI identified bone involvement and extension of disease into the thecal sac earlier and more readily. Three patients had an indeterminate mediastinal finding on CT that was correctly identified as a benign cyst or pericardial fluid collection by MRI. CONCLUSION: MRI is an alternative option to follow-up patients after treatment for TEM. However, for those with metallic sternotomy wires, we recommend alternating the follow-up with CT as well.

Recurrent acute cellular rejection graded ISHLT 1R early after heart transplantation negatively affects long-term outcomes: The prognostic significance of 1990 ISHLT grades 1B and 2.

PURPOSE: We investigated the implications of early recurrent 1R rejections for long-term outcomes after heart transplantation (HT) and evaluated the prognostic significance of 1990 ISHLT grading 1B/2 versus 1A. METHODS: Data on all patients who underwent HT between 1992 and 2017 were reviewed. Patients with ≥2 endomyocardial biopsies graded 1R in the first 3 months were classified as "recurrent 1R." Those patients were further categorized according to 1A vs. 1B/2. Outcomes (>3 months) were long-term rejections and the combined endpoint of cardiac allograft vasculopathy (CAV) and cardiovascular (CV) mortality. RESULTS: Sixty-nine out of 228 patients were classified as recurrent grade 1R. In the recurrent 1R group, 2R rejection rate was significantly higher (2.6 ±â€¯0.6 vs 1.2 ±â€¯0.4, p = 0.03), while survival free of rejections was lower (5-year: 57.1% vs. 72.3%, p = 0.022). Multivariate analysis showed that early recurrent 1R rejection was associated with a 30% increased risk for subsequent major rejection. Among 28 patients classified as 1B/2 of the recurrent group, rejection scores were higher, while survival free of rejections was lower, compared to 37 patients of the recurrent group classified as 1A (5-year: 57.1% vs. 72.7%, p = 0.013). Kaplan-Meier analysis showed that CAV/CV mortality at 10 years of follow-up was significantly higher among the recurrent 1R group (38% vs. 18% p < 0.05). Multivariate analysis showed that early recurrent 1R rejections were associated with a 2.5-fold increased risk for CAV/CV mortality. CONCLUSION: Early recurrent grade 1R rejections negatively affect long-term outcomes. The adverse outcomes are experienced mainly by 1R patients subcategorized as1B/2 and not 1A.

Flexible bronchoscopy and cryoextraction for critical airway obstruction caused by an endobronchial angioleiomyoma.

Angioleiomyomas are rare airway tumours with potential to cause central airway obstruction or haemoptysis. Methods described to manage them include surgical resection, or rigid bronchoscopy and thermal ablation techniques. We describe a case presenting with central airway obstruction, safely and effectively treated with cryoextraction of the tumour using flexible bronchoscopy.

Comparative effectiveness of intensity modulated radiation therapy to 3-dimensional conformal radiation in locally advanced lung cancer: pathological and clinical outcomes.

OBJECTIVE: Intensity-modulated radiotherapy (IMRT) has better normal-tissue sparing compared with 3-dimensional conformal radiation (3DCRT). We sought to assess the impact of radiation technique on pathological and clinical outcomes in locally advanced non-small cell lung cancer (LANSCLC) treated with a trimodality strategy. METHODS: Retrospective review of LANSCLC patients treated from August 2012 to August 2018 at Sheba Medical Center, Israel. The trimodality strategy consisted of concomitant chemoradiation to 60 Gray (Gy) followed by completion surgery. The planning target volume (PTV) was defined by co-registered PET/CT. Here we compare the pathological regression, surgical margin status, local control rates (LC), disease free (DFS) and overall survival (OS) between 3DCRT and IMRT. RESULTS: Our cohort consisted of 74 patients with mean age 62.9 years, male in 51/74 (69%), adenocarcinoma in 46/74 (62.1%), stage 3 in 59/74 (79.7%) and chemotherapy in 72/74 (97.3%). Radiation mean dose: 59.2 Gy (SD ± 3.8). Radiation technique : 3DCRT in 51/74 (68.9%), IMRT in 23/74 (31%). Other variables were similar between groups.Major pathological response (including pathological complete response or less than 10% residual tumor cells) was similar: 32/51 (62.7%) in 3DCRT and 15/23 (65.2%) in IMRT, p=0.83. Pathological complete response (pCR) rates were similar: 17/51 (33.3%) in 3DCRT and 8/23 (34.8%) in IMRT, p=0.9. Surgical margins were negative in 46/51 (90.1%) in 3DCRT vs. 17/19 (89.4%) in IMRT (p=1.0).The 2-year LC rates were 81.6% (95% CI 69-89.4%); DFS 58.3% (95% CI 45.5-69%) and 3-year OS 70% (95% CI57-80%). Comparing radiation techniques, there were no significant differences in LC (p=0.94), DFS (p=0.33) and OS (p=0.72). CONCLUSION: When used to treat LANSCLC in the neoadjuvant setting, both IMRT and 3DCRT produce comparable pathological and clinical outcomes. ADVANCES IN KNOWLEDGE: This study validates the real-world effectiveness of IMRT compared to 3DCRT.

De novo mitral regurgitation as a cause of heart failure exacerbation in patients with hypertrophic cardiomyopathy.

AIMS: To determine the prevalence and mechanisms of de novo severe MR due to mitral valve structural abnormalities causing clinical deterioration in patients with HCM. METHODS AND RESULTS: This is an observational study based on HCM registry comprising consecutive HCM patients (n=397) who have been evaluated and followed in the Cardiomyopathy Clinic of Sheba Medical Center. Sixteen patients (4.0%), 8 males, mean age 65±14 years, developed acute clinical deterioration due to development of severe mitral regurgitation unrelated to mitral valve systolic anterior motion. Compared to the remaining HCM population, those patients were older at their initial diagnosis (51±20 vs. 38±18 years) and more often females. Most frequently (in 10 patients, 63%) mitral regurgitation resulted from a flail posterior leaflet, while 4 patients had severe prolapse and 2 had isolated mitral annular/leaflet calcifications. Fourteen underwent surgery; myxomatous changes were found in all excised valves (n=9). On age-adjusted univariate analysis, 3 clinical parameters remained significantly associated with the development of de novo MR, female gender, LVOT obstruction and significant MR at baseline. On multivariable analysis, only LVOT obstruction (HR=3.8) and MR at baseline evaluation (HR=8.2) predicted development of severe MR. CONCLUSIONS: De novo severe MR leading to acute heart failure was repeatedly observed in our HCM series. This etiology needs to be considered as a cause of acute clinical deterioration in these patients.

Risk of early, intermediate, and late rejection following heart transplantation: Trends over the past 25 years and relation to changes in medical management. Tertiary center experience: The Sheba Heart Transplantation Registry.

AIM: To explore the trends in the risk for rejection following heart transplantation (HT) over the past 25 years, and their relation to changes in medical management. METHODS: The study population comprised 216 HT patients. Rejection periods were defined as follows: 0-3 months (early), 3-12 months (intermediate), and 12+ months (late). HT era was dichotomized as follows: 1991-1999 (remote era) and 2000-2016 (recent era). Medication combination was categorized as newer (TAC, MMF, and everolimus) vs older therapies (AZA, CSA). RESULTS: Multivariate analysis showed that patients who underwent HT during the recent era experienced a significant reduction in the risk for major rejection. These findings were consistent for early (OR = 0.44 [95% CI 0.22-0.88]), intermediate (OR = 0.02 [95% CI 0.003-0.11]), and late rejections (OR = 0.18 [95% CI 0.05-0.52]). Using the year of HT as a continuous measure showed that each 1-year increment was independently associated with a significant reduction in the risk for early, intermediate, and late rejections (5%, 21%, 18%, respectively). In contrast, the risk reduction associated with newer types of immunosuppressive therapies was not statistically significant after adjustment for the treatment period. CONCLUSIONS: Major rejection rates following HT have significantly declined over the past 2 decades even after adjustment for changes in immunosuppressive therapies, suggesting that other factors may also play a role in the improved outcomes of HT recipients.

A novel immune resistance mechanism of melanoma cells controlled by the ADAR1 enzyme.

The blossom of immunotherapy in melanoma highlights the need to delineate mechanisms of immune resistance. Recently, we have demonstrated that the RNA editing protein, adenosine deaminase acting on RNA-1 (ADAR1) is down-regulated during metastatic transition of melanoma, which enhances melanoma cell proliferation and tumorigenicity. Here we investigate the role of ADAR1 in melanoma immune resistance.Importantly, knockdown of ADAR1 in human melanoma cells induces resistance to tumor infiltrating lymphocytes in a cell contact-dependent mechanism. We show that ADAR1, in an editing-independent manner, regulates the biogenesis of miR-222 at the transcription level and thereby Intercellular Adhesion Molecule 1 (ICAM1) expression, which consequently affects melanoma immune resistance. ADAR1 thus has a novel, pivotal, role in cancer immune resistance. Corroborating with these results, the expression of miR-222 in melanoma tissue specimens was significantly higher in patients who had no clinical benefit from treatment with ipilimumab as compared to patients that responded clinically, suggesting that miR-222 could function as a biomarker for the prediction of response to ipilimumab.These results provide not only novel insights on melanoma immune resistance, but also pave the way to the development of innovative personalized tools to enable optimal drug selection and treatment.