Temporal genomic analysis of melanoma rejection identifies regulators of tumor immune evasion

Decreased intra-tumor heterogeneity (ITH) correlates with increased patient survival and immunotherapy response. However, even highly homogenous tumors may display variability in their aggressiveness, and how immunologic-factors impinge on their aggressiveness remains understudied. Here we studied the mechanisms responsible for the immune-escape of murine tumors with low ITH. We compared the temporal growth of homogeneous, genetically-similar single-cell clones that are rejected vs. those that are not-rejected after transplantation in-vivo using single-cell RNA sequencing and immunophenotyping. Non-rejected clones showed high infiltration of tumor-associated-macrophages (TAMs), lower T-cell infiltration, and increased T-cell exhaustion compared to rejected clones. Comparative analysis of rejection-associated gene expression programs, combined with in-vivo CRISPR knockout screens of candidate mediators, identified Mif (macrophage migration inhibitory factor) as a regulator of immune rejection. Mif knockout led to smaller tumors and reversed non-rejection-associated immune composition, particularly, leading to the reduction of immunosuppressive macrophage infiltration. Finally, we validated these results in melanoma patient data.

[Transition, fertility and options for preservation of fertility]

Oftentimes ignored or infrequently expressed, some transgender persons harbor a desire for parenthood. Given the evolution of medical techniques and the enacting of legislative reforms, it is henceforth possible to propose fertility preservation strategies in the overall context of gender transidentity. During the "female to male" (FtM) transition pathway, androgen therapy has an impact on gonadic function, generally inducing blockage of the ovarian function, with amenorrhea. Even though these events may be reversed on cessation of treatment, the possible long-term effects on future fertility and on the health of children yet to be born are little known. Moreover, transition surgeries definitively compromise the possibility of pregnancy insofar as they involve bilateral adnexectomy and/or hysterectomy. Options for fertility preservation in the framework of FtM transition are premised on cryopreservation of oocytes and/or ovarian tissue. In a comparable manner, even though relevant documentation is lacking, hormonal treatments for persons transitioning from male to female (MtF) can have an impact on future fertility. In the event of surgery involving bilateral orchidectomy in which spermatozoid cryopreservation has not been carried out, fertility is definitively impossible. In both cases and under present-day legislation, numerous legal and regulatory barriers render highly problematic the reutilization of cryopreserved gametes. Given these different constraints, it is indispensable to closely supervise these types of treatment by proposing psychological support.

Role of ATP Binding Cassette Subfamily A Member 1 (ABCA1) in Chemoradiotherapy-induced Renal Injury

PURPOSE/OBJECTIVE(S)

Radiation therapy (RT) alone or combined with chemotherapy reduces cholesterol efflux and causes chronic kidney disease (CKD). There is no treatment for CKD except renal replacement strategies such as dialysis or transplantation. We hypothesize that cancer treatment-induced ABCA1 deficiency leads to dysregulation of cholesterol metabolism, making podocytes susceptible and cancerous cells resistant to treatment-induced injuries.

MATERIALS/METHODS

To quantify the cell index of LNCaP, 786-0, and Podcytes were grown in an e-plate reader (Roche) for 24 h and then were treated with either enzalutamide (10µM) or sunitinib (1.0 µM) or cyclophosphamide (10µM) with or without RT (4Gy) or ABCA1 inducer (liver-X-receptors agonist (GW3965; Sigma; 10µM). Podocyte cholesterol efflux assay was measured using NBD-cholesterol efflux assay, and expression of ABCA1 and cleaved caspase-3 were measured by western blotting. 10-14-week-old C57BL/6 male and female mice were given bilateral kidney X-irradiation of 4Gy with or without cisplatin (3mg/kg; IV). Functional kidney parameters, histopathological changes, and ultrastructural changes were measured at baseline and 20 weeks after treatment. GFR was measured using a FITC-sinistrin-based transdermal monitor.

RESULTS

In vitro studies suggest that after radiation exposure (4Gy and 8Gy), ABCA1 expression decreases in a dose and time-dependent manner in cultured podocytes (p < 0.05), which coincides with reduced cholesterol efflux (p < 0.05) and increased podocyte apoptosis (p < 0.01). In contrast, LXR agonist treatment in vitro prevents reduced ABCA1 expression and cholesterol efflux and prevents podocytes from radiation-induced apoptosis. Our in vitro studies further suggest that Enzalutamide treatment alone reduces the growth of LNCaP and podocytes, and RT (5Gy) plus enzalutamide combination treatment further decreases the growth of LNCaP and podocytes. However, LXR agonist treatment further increased the efficacy of enzalutamide and RT treatment against LNCaP and increased podocyte growth simultaneously. Similarly, Sunitinib with or without RT reduces the growth of renal cancer cells (786-0) and podocytes. LXR agonist treatment further increases the efficacy of the sunitinib and RT against 786-0 cells and simultaneously increases podocyte growth. Cyclophosphamide reduces the growth of the podocytes, and LXR agonist treatment improves the podocyte growth after CP treatment. In vivo studies observed that focal bilateral kidney irradiation with or without cisplatin of C57BL/6 mice induces lipid accumulation in the kidney cortex and increases GBM thickness (p < 0.001), which correlates with decreased Abca1 expression, podocyte number, and GFR.

CONCLUSION

This study shows that LXR agonist treatment protects podocytopathy in vitro and chemotherapy or radiotherapy-induced kidney injury in vivo. ABCA1 may be an important therapeutic target for chemoradiotherapy-induced kidney injuries in cancer patients.

Arterial Spin-Labeling in the Assessment of Pediatric Nontraumatic Orbital Lesions

Benign and malignant pediatric orbital lesions can sometimes have overlapping features on conventional MR imaging sequences. MR imaging of 27 children was retrospectively reviewed to describe the signal of some common pediatric extraocular orbital lesions on arterial spin-labeling and to evaluate whether this sequence helps to discriminate malignant from benign masses, with or without ADC value measurements. Qualitative and quantitative assessments of arterial spin-labeling CBF and ADC were performed. All lesions were classified into 3 arterial spin-labeling perfusion patterns: homogeneous hypoperfusion (pattern 1, n = 15; benign lesions), heterogeneous hyperperfusion (pattern 2, n = 9; cellulitis, histiocytosis, malignant tumors), and homogeneous intense hyperperfusion (pattern 3, n = 3; infantile hemangiomas). Arterial spin-labeling can be a valuable tool to improve the diagnostic confidence of some orbital lesions, including infantile hemangioma. An algorithm is proposed.

Large-Scale Immuno-Peptidome Analysis Reveals Recurrent Post-Translational Splicing of Cancer and Immune-Associated Genes

Post-translational spliced peptides (PTSPs) are a unique class of peptides that have been found to be presented by HLA-class-I molecules in cancer (1). Thus far, no consensus has been reached on the proportion of PTSPs in the immunopeptidome, with estimates ranging from 2% to as high as 45% and stirring significant debate (2-8). Furthermore, the role of the HLA-class-II pathway in PTSP presentation has been studied only in diabetes (9). Here, we exploit our large-scale cancer peptidomics database and our newly devised pipeline for filtering spliced peptide predictions to identify recurring spliced peptides, both for HLA-class-I and -II complexes. Our results indicate that HLA-class-I spliced peptides account for a low percentage of the immunopeptidome (less than 3.1%), yet are larger in number relative to other types of identified aberrant peptides. Therefore, spliced peptides significantly contribute to the repertoire of presented peptides in cancer cells. In addition, we identified HLA-class-II-bound spliced peptides, but to a lower extent (less than 0.5%). The identified spliced peptides include cancer- and immune-associated genes, such as the MITF oncogene, DAPK1 tumor suppressor and HLA-E, which were validated using synthetic peptides. The potential immunogenicity of the DAPK1- and HLA-E-derived PTSPs was also confirmed. In addition, a reanalysis of our published mouse single-cell clone immunopeptidome dataset showed that most of the spliced peptides were found repeatedly in a large number of the single-cell clones. Establishing a novel search-scheme for the discovery and evaluation of recurring PTSPs among cancer patients may assist in identifying potential novel targets for immunotherapy.

Rituximab Chimeric Anti-CD20 Monoclonal Antibody Therapy for Relapsed Indolent Lymphoma: Half of Patients Respond to a Four-Dose Treatment Program

PURPOSE

The CD20 antigen is expressed on more than 90% of B-cell lymphomas. It is appealing for targeted therapy, because it does not shed or modulate. A chimeric monoclonal antibody more effectively mediates host effector functions and is itself less immunogenic than are murine antibodies.

PATIENTS AND METHODS

This was a multiinstitutional trial of the chimeric anti-CD20 antibody, IDEC-C2B8. Patients with relapsed low grade or follicular lymphoma received an outpatient treatment course of IDEC-C2B8 375 mg/m2 intravenously weekly for four doses.

RESULTS

From 31 centers, 166 patients were entered. Of this intent-to-treat group, 48% responded. With a median follow-up duration of 11.8 months, the projected median time to progression for responders is 13.0 months. Serum antibody levels were sustained longer after the fourth infusion than after the first, and were higher in responders and in patients with lower tumor burden. The majority of adverse events occurred during the first infusion and were grade 1 or 2; fever and chills were the most common events. Only 12% of patients had grade 3 and 3% grade 4 toxicities. A human antichimeric antibody was detected in only one patient.

CONCLUSION

The response rate of 48% with IDEC-C2B8 is comparable to results with single-agent cytotoxic chemotherapy. Toxicity was mild. Attention needs to be paid to the rate of antibody infusion, with titration according to toxicity. Further investigation of this agent is warranted, including its use in conjunction with standard chemotherapy.

High-clearance anti-amyloid immunotherapies in Alzheimer's disease. Part 1: Meta-analysis and review of efficacy and safety data, and medico-economical aspects

In 2021, aducanumab, an immunotherapy targeting amyloid-β, was approved for Alzheimer's disease (AD) by the US Food and Drug Administration thanks to positive results on a putative biological surrogate marker. This approval has raised an unprecedented controversy. It was followed by a refusal of the European Medicine Agency, which does not allow the marketing of drugs solely on biological arguments and raised safety issues, and important US coverage limitations by the Centers for Medicare & Medicaid Services. Two other anti-amyloid immunotherapies showed significant results regarding a clinical outcome in phase 2 trials, and five drugs are being studied in phase 3 trials. Compared to those tested in previous trials of the 2010s, the common feature and novelty of these anti-amyloid immunotherapies is their ability to induce a high clearance of amyloid load, as measured with positron emission tomography, in the brain of early-stage biomarker-proven AD patients. Here, we review the available evidence regarding efficacy and safety data and medico-economical aspects for high-clearance anti-amyloid immunotherapies. We also perform frequentist and Bayesian meta-analyses of the clinical efficacy and safety of the highest dose groups from the two aducanumab phase 3 trials and the donanemab and lecanemab phase 2 trials. When pooled together, the data from high-clearance anti-amyloid immunotherapies trials confirm a statistically significant clinical effect of these drugs on cognitive decline after 18 months (difference in cognitive decline measured with CDR-SB after 18 months between the high dose immunotherapy groups vs. placebo = -0.24 points; P=0.04, frequentist random-effect model), with results on ADAS-Cog being the most statistically robust. However, this effect remains below the previously established minimal clinically relevant values. In parallel, the drugs significantly increased the occurrence of amyloid-related imaging abnormalities-edema (ARIA-E: risk ratio=13.39; P<0.0001), ARIA-hemorrhage (risk ratio=2.78; P=0.0002), and symptomatic and serious ARIA (7/1321=0.53% in the high dose groups versus 0/1446 in the placebo groups; risk ratio=6.44; P=0.04). The risk/benefit ratio of high-clearance immunotherapies in early AD is so far questionable after 18 months. Identifying subgroups of better responders, the perspective of combination therapies, and a longer follow-up may help improve their clinical relevance. Finally, the preliminary evidence from medico-economical analyses seems to indicate that the current cost of aducanumab in the US is not in reasonable alignment with its clinical benefits.

High-clearance anti-amyloid immunotherapies in Alzheimer's disease. Part 2: putative scenarios and timeline in case of approval, recommendations for use, implementation, and ethical considerations in France

In 2021, aducanumab, an immunotherapy targeting amyloid-β, was approved for Alzheimer's disease (AD) by the US Food and Drug Administration thanks to positive results on a putative biological surrogate marker. This approval has raised an unprecedented controversy. It was followed by a refusal of the European Medicine Agency, which does not allow the marketing of drugs solely on biological arguments and raised safety issues, and important US coverage limitations by the Centers for Medicare & Medicaid Services. Two other anti-amyloid immunotherapies showed significant results regarding a clinical outcome in phase II trials, and five drugs are being studied in phase III trials. Lecanemab is currently under examination for an 'Accelerated Approval' in the US, with an expected decision in January 2023. The common feature and novelty of these anti-amyloid immunotherapies, compared to those tested in previous trials of the 2010s, is their ability to induce a high clearance of amyloid load, as measured with positron emission tomography, in the brain of early-stage biomarker-proven AD patients. In the first part of this review, we underlined through a meta-analysis that the pooled data from high-clearance anti-amyloid immunotherapies trials demonstrated a significant but slight clinical effect after 18 months. Still, safety remains an issue with serious and symptomatic amyloid-related imaging abnormalities, which are seldom (∼1 per 200 treated patients) but occur beyond chance. In the second part of this review, we hypothesized that there is a high probability that some phase III trials of high-clearance anti-amyloid immunotherapies in early AD will finally be unarguably positive on clinical outcomes in the next five years with acceptable safety data. This may, in turn, lead to approval by the European Medicine Agency if the risk-benefit profile is deemed favorable. Such approval would be a game-changer in managing AD patients and for the organization of memory clinics in France. We review the possible timeline and scenarios for putative approval in France and make propositions regarding putative use in clinical practice, putative implementation in a real-life setting, and ethical considerations.

Arterial Spin-Labeling Perfusion Imaging in the Early Stage of Sturge-Weber Syndrome

BACKGROUND AND PURPOSE

Sturge-Weber syndrome is a rare congenital neuro-oculo-cutaneous disorder. Although the principal mechanism of Sturge-Weber syndrome is characterized by a leptomeningeal vascular malformation, few data regarding perfusion abnormalities of the brain parenchyma are available. Therefore, the aim of this study was to assess the diagnostic performance of arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome before 1 year of age until 3.5 years of age. We hypothesized that a leptomeningeal vascular malformation has very early hypoperfusion compared with controls with healthy brains.

MATERIALS AND METHODS

We compared the CBF using arterial spin-labeling perfusion imaging performed at 3T MR imaging in the brain parenchymal regions juxtaposing the leptomeningeal vascular malformation in patients with Sturge-Weber syndrome (n = 16; 3.5 years of age or younger) with the corresponding areas in age-matched controls with healthy brains (n = 58). The analysis was performed following two complementary methods: a whole-brain voxel-based analysis and a visual ROI analysis focused on brain territory of the leptomeningeal vascular malformation.

RESULTS

Whole-brain voxel-based comparison revealed a significant unilateral decrease in CBF localized in the affected cortices of patients with Sturge-Weber syndrome (P < .001). CBF values within the ROIs in patients with Sturge-Weber syndrome were lower than those in controls (in the whole cohort: median, 25 mL/100g/min, versus 44 mL/100g/min; P < .001). This finding was also observed in the group younger than 1 year of age, emphasizing the high sensitivity of arterial spin-labeling in this age window in which the diagnosis is difficult.

CONCLUSIONS

Arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome can help to diagnose the disease by depicting a cortical hypoperfusion juxtaposing the leptomeningeal vascular malformation.

P-057 Machine learning-based prediction of testicular sperm extraction: comparison of different preprocessing and models, required sample size and relevance of input biomarkers

Study question

Can advanced machine learning applied to the preoperative assessment predict the testicular sperm extraction outcome in azoospermic context and how many patients are required?

Summary answer

Despite encouraging results (AUC = 92.0%, sensitivity = 83.9% and specificity = 84.2%), integrating new biomarkers would probably be more relevant than enrolling additional patients.

What is known already

Testicular sperm extraction (TESE) is an essential therapeutic tool for the male infertility management and is often the “last hope” before gamete donation for these patients. However, it is an invasive procedure and is successful in up to 50%. Until now, no model is sufficiently powerful to accurately predict the success of sperm retrieval in TESE. Among the few models already developed, the findings are highly disparate despite having common input data (preoperative assessment). Moreover, only few types of machine learning models and procedures have been investigated. Performances were mostly capped despite the inclusion sometimes of more than 1000 patients.

Study design, size, duration

Data of 175 patients who underwent TESE between 2012 and 2021 were retrospectively analyzed. The performances of a wide range of preprocessing methods and machine learning models (state-of-the-art methods in machine learning) we explored, evaluated, and compared. The objective was to predict the presence or absence of spermatozoa, using 17 parameters (clinical, hormonal, genetic, history) from the preoperative assessment. The study protocol was approved by a local ethics committee (IRB CER-2021-041).

Participants/materials, setting, methods

After data preprocessing (standardization…), Machine Learning models (Bayesian Naive Classification, logistic regression, k-nearest neighbor classifier, support vector machine, random forests, GradientBoosting and XGBoost) and Deep Learning models were tested. The validation procedure consisted of splitting the dataset into a training set and test set. Beyond the standard metrics (sensitivity, specificity, AUC-ROC), the identification of the most relevant variables and the learning curve to determine the optimal patient number to be included were performed.

Main results and the role of chance

At least one live spermatozoon was found in the testicular tissue of 104 (59.4%) patients (positive TESE) out of 175. The best performing model (Random Forest with appropriate preprocessing) obtained the following results on the test set: AUC = 92.0%, sensitivity = 83.9% and specificity = 84.2%, leading to an efficient tool, which gives additional and more relevant information than the different variables taken separately. Inhibin B, FSH and history of cryptorchidism were the variables with the most discriminating power. However, a plateau in the model performance was observed (beyond 110 patients), whatever the approach or the preprocessing used. A trend curve shows that beyond 110 patients, no improvement can be observed and cast doubt about the power of the traditional preoperative parameters assessed before TESE. The classic preoperative assessment can probably not fully predict the TESE outcomes. Further work is needed to be enhance with new hypothesis and the use of new biomarkers to be integrated into the models.

Limitations, reasons for caution

The main limitation was the monocentric design and the use of retrospective data.

Wider implications of the findings

Machine learning models can provide the basis for an enhanced decision support system tool in the context of azoospermia. Indefinitely increasing the number of participants is not likely to be the solution: further hypotheses and biomarkers integration into the models will probably be necessary to improve performance.

Trial registration number

not applicable

Combined presentation and immunogenicity analysis reveals a recurrent RAS.Q61K neoantigen in melanoma

Neoantigens are now recognized drivers of the antitumor immune response. Recurrent neoantigens, shared among groups of patients, have thus become increasingly coveted therapeutic targets. Here, we report on the data-driven identification of a robustly presented, immunogenic neoantigen that is derived from the combination of HLA-A*01:01 and RAS.Q61K. Analysis of large patient cohorts indicated that this combination applies to 3% of patients with melanoma. Using HLA peptidomics, we were able to demonstrate robust endogenous presentation of the neoantigen in 10 tumor samples. We detected specific reactivity to the mutated peptide within tumor-infiltrating lymphocytes (TILs) from 2 unrelated patients, thus confirming its natural immunogenicity. We further investigated the neoantigen-specific clones and their T cell receptors (TCRs) via a combination of TCR sequencing, TCR overexpression, functional assays, and single-cell transcriptomics. Our analysis revealed a diverse repertoire of neoantigen-specific clones with both intra- and interpatient TCR similarities. Moreover, 1 dominant clone proved to cross-react with the highly prevalent RAS.Q61R variant. Transcriptome analysis revealed a high association of TCR clones with specific T cell phenotypes in response to cognate melanoma, with neoantigen-specific cells showing an activated and dysfunctional phenotype. Identification of recurrent neoantigens and their reactive TCRs can promote "off-the-shelf" precision immunotherapies, alleviating limitations of personalized treatments.

Continuous monitoring of advanced hemodynamic parameters shows early cardiovascular changes in a cohort of 492 COVID-19 hospitalized patients

Background

COVID-19 exerts deleterious cardiopulmonary effects, leading to worse prognosis in the most effected.

Purpose

The aim of this retrospective multi-center observational cohort study was to analyze the trajectories of key advanced hemodynamic parameters amongst hospitalized COVID-19 patients according to different risk populations using a chest-patch wearable providing continuous remote patient monitoring.

Methods

The study was conducted in five COVID-19 isolation units. Patients admitted to the units were connected to a photoplethysmography based noninvasive remote advanced hemodynamic monitor after completing a basic risk factor survey. Physiological parameters were measured every 15 minutes during the hospitalization, including cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), heart rate, blood pressure (BP), respiratory rate, blood oxygen saturation (SpO2), and body temperature.

Results

492 COVID-19 patients (179 females, average age 58.7 years) were included in the final analysis, with more than 3 million measurements collected during an average of 75.3 hours. Overall, within the first five days of hospitalizations we found a significant increase in SVR, and a significant decrease in SpO2, DBP, CO and CI (p&lt;0.01 for all). The changes were more prominent in high risk populations- males, older age and obesity and had a temporal correspondence to changes in respiratory parameters.

Conclusions

This is the first comprehensive continuous advanced hemodynamic profiling of COVID-19 patients. Worse hemodynamic status was prominent in high risk populations.

Funding Acknowledgement

Type of funding sources: None.

O-182 Higher risk of preeclampsia and pregnancy-induced hypertension with artificial cycle for Frozen-thawed Embryo Transfer compared to ovulatory cycle or fresh transfer following In Vitro Fertilization

Study question

Is there an increased risk of preeclampsia after Frozen-thawed Embryo Transfer(FET) compared to In Vitro Fertilization-fresh transfer(IVF-fresh-ET) according to endometrial type of preparation for FET?

Summary answer

The frequency of preeclampsia and hypertension were significantly higher in the group of artificial cycle (AC-FET) compared to ovulatory cycle (OC-FET) and fresh-ET (P &lt; 0.0001).

What is known already

Risks of maternal morbidity are known to be reduced in pregnancies resulting from FET compared to fresh-ET except for the risk of preeclampsia, that was reported to be significantly higher in pregnancies resulting from FET compared to fresh-ET or spontaneous conception. Most recent studies demonstrate an equal live birth rate with either OC-FET or AC-FET preparation. Few studies compared the maternal vascular morbidities with the two hormonal environments that preside over the early stages of embryonic development: OC (major role of the corpus luteum) and AC (prolonged hormone replacement with high doses of estrogen and progesterone).

Study design, size, duration

We conducted a 2013-2018 French nationwide cohort study comparing maternal vascular morbidities in 3 groups of single pregnancies&gt; 22 weeks of gestation (WG): FET with AC or OC preparation, and IVF (conventional or ICSI)-fresh-ET.Data were extracted from the French National Health System database (&gt;99% of national deliveries) in which all hospitalizations are registered, containing information on patient characteristics, diagnoses and treatments. Records were merged anonymously. Access to the database was legally approved.

Participants/materials, setting, methods

68 025 deliveries were included: fresh-ET(n = 48 152), OC-FET(n = 9 500), AC-FET(n = 10 373). In OC-FET, a luteal phase support with progesterone was administered for maximum 6 WG if pregnancy. In AC-FET, progesterone was co-administered with estrogen until 12 WG. Embryos were transferred at cleavage or blastocyst stage.

Vascular disorders were recorded if hospitalization for preeclampsia/eclampsia or hypertension (history of hypertension excluded). Maternal characteristics were included in multivariate analysis. Adjusted odds ratios(aOR) and 95% confidence intervals(CI) were estimated.

Main results and the role of chance

Maternal characteristics: In multivariate analysis, patients in the FET groups were older (33.4 years (std=4.3) vs. 33.2 years (std=4.4) for fresh-ET, respectively, P &lt; 0.0001), less often primiparous (aOR=0.68[0.66-0.71], P &lt; 0.0001) or smokers (aOR=0.84[0.75-0.95]) or with premature ovarian insufficiency (POI) (aOR=0.68 [0.58-0.79]), more frequently with polycystic ovaries (PCOS) (aOR=1.25[1.12-1.39]) and comparable for obesity or diabetes.

In FET groups, 52.2% were AC-FET. There was no difference for maternal age, parity, obesity, smoking, history of diabetes between AC and OC-FET. Endometriosis (aOR=1.26[1.16-1.38]), PCOS (aOR=1.79[1.50-2.15]) and POI (aOR=2.0[1.48-2.72]) were more frequent in AC-FET.

Risks of vascular disorders

The rate of preeclampsia (5.3% vs. 2.3% vs. 2.4%, respectively, P &lt; 0.0001) and hypertension (4.7% vs. 3.4% vs. 3.3%, respectively, P = 0.0002) was significantly higher in AC-FET versus OC-FET and fresh-ET.

In multivariate analysis, the risk of preeclampsia increased with age, primiparity, obesity, diabetes and POI. The risk was higher in AC-FET versus OC-FET (aOR=2.42 [2.06-2.85]) and fresh-ET (aOR=2.43[2.2-2.7]), P &lt; 0.00001. No difference was found between OC-FET and fresh-ET (P = 0.91). The risk of pregnancy-induced hypertension increased with age &gt;40, primiparity, smoking, obesity and diabetes and was higher in AC-FET versus OC-FET (aOR=1.50[1.29-1.74], P &lt; 0.0001) and fresh-ET (aOR=1.50[1.35-1.67], P &lt; 0.0001) and not different between OC-FET and fresh-ET (P = 0.86).

Limitations, reasons for caution

While the strength of this study relies in the number and exhaustiveness of subjects analysed, its limitations are its retrospective and register-based nature that did not enable to refine the risk according to details of techniques and treatments in each group.

Wider implications of the findings

This large nationwide cohort study highlights 2 important information for physicians : i) the possible deleterious role of high supra-physiological and prolonged doses of estrogen-progesterone supplementation on vascular pathologies ii) the protective role of the corpus luteum present in stimulated or spontaneous OC for their prevention.

Trial registration number

Not applicable

POS0739 DEVELOPMENT OF A CONCEPTUAL MODEL TO UNDERSTAND DISEASE BURDEN IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS AND LONG-TERM ORGAN DAMAGE

Background:

Systemic lupus erythematosus (SLE) is a chronic, multisystem, autoimmune disease resulting in increased morbidity and mortality and reduced health-related quality of life (HRQoL). Patients with SLE are at risk of developing irreversible long-term organ damage (LTOD) caused by both disease activity and cumulative medication toxicities. Data regarding the overall disease burden and impact of LTOD in patients with SLE are limited.

Objectives:

The primary objective of this qualitative study was to develop a conceptual model to describe the burden experienced by patients with SLE and LTOD.

Methods:

This study (GSK Study 209754) was conducted in three phases. First, a targeted literature review was performed to aid the development of an initial draft conceptual model. Key opinion leaders (KOLs) with experience in SLE and LTOD were then interviewed to assess the clarity, language, comprehensibility, and potential use of the conceptual model, and to help shape the patient interview materials. Finally, one-on-one interviews were performed with patients with SLE and LTOD in any of the 12 organ areas (defined by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index [SDI]), to gather patient perspectives on the common symptoms, functional impacts, treatment experiences, and HRQoL factors associated with LTOD. Data from the interviews were coded and analysed using NVivo software to identify patterns in responses concerning the key concepts of the overall patient burden of LTOD, and used to identify concepts to include in the model.

Results:

The literature review produced the preliminary conceptual model of LTOD. Results of the KOL interviews (n=5 clinicians and n=1 patient advocate) indicated that the preliminary conceptual model broadly captured the patient experience of LTOD. KOLs emphasised the difference between SLE activity (flares) and LTOD; the conceptual model was subsequently updated in accordance with these recommendations. Interviews conducted with patients with confirmed single (n=9) and multiple LTOD (n=31) indicated that the burden of LTOD associated with SLE was more severe, debilitating, and life threatening than that caused by SLE flares. Almost all patients (39/40) reported aspects of their lives that were more severely affected since their LTOD diagnosis. All 40 patients reported LTOD-related physical impacts, which often affected patients’ ability to perform everyday tasks. The most frequent physical impacts reported were a loss of vitality (39/40), long-term complications (e.g. unstable blood pressure, extreme pain, poor mobility, inflammation, dialysis, infection; 36/40), and severe fatigue (29/40). Cognitive impairments that became more pronounced after their LTOD diagnosis were reported by 27/40 of patients. Typically characterised as “brain fog”, these impairments were described as slower cognitive processing, forgetfulness, confusion, and aphasia. Economic impacts associated with LTOD included patients’ inability to work (31/40), costs of care (33/40), and non-medical-related costs (17/30). Psychosocial impacts reported by patients with LTOD affected their emotional state (39/40), ability to socialise (40/40) and relationships (30/40). Additionally, 30/40 patients reported symptoms as more severe since their LTOD diagnosis, including pain (14/40), fatigue (9/40), and oedema (8/40). Patients’ treatment goals were largely aligned with their experienced impacts of LTOD, including managing the disease and symptoms (25/40), limiting further organ damage (15/40), and improving HRQoL (11/40).

Conclusion:

The findings from this research clearly indicate that the patient burden of LTOD far surpasses that of SLE without LTOD. These data were incorporated and refined into a conceptual model that fully represents the patient experience of LTOD. The model will help researchers, clinicians, and patients to better understand the impact of SLE-related LTOD progression.

Funding:

GSK

Acknowledgements:

Medical writing assistance was provided by Casmira Brazaitis, PhD, Fishawack Indicia Ltd., UK, part of Fishawack Health, and was funded by GSK.

Disclosure of Interests:

Lynne Broderick Consultant of: GSK, Wen-Hung Chen Shareholder of: GSK, Employee of: GSK, Roger Levy Shareholder of: GSK, Employee of: GSK, April Foster Consultant of: GSK, Cindy Umanzor Consultant of: GSK, Deven Chauhan Shareholder of: GSK, Employee of: GSK

Identification of bacteria-derived HLA-bound peptides in melanoma

A variety of species of bacteria are known to colonize human tumours1-11, proliferate within them and modulate immune function, which ultimately affects the survival of patients with cancer and their responses to treatment12-14. However, it is not known whether antigens derived from intracellular bacteria are presented by the human leukocyte antigen class I and II (HLA-I and HLA-II, respectively) molecules of tumour cells, or whether such antigens elicit a tumour-infiltrating T cell immune response. Here we used 16S rRNA gene sequencing and HLA peptidomics to identify a peptide repertoire derived from intracellular bacteria that was presented on HLA-I and HLA-II molecules in melanoma tumours. Our analysis of 17 melanoma metastases (derived from 9 patients) revealed 248 and 35 unique HLA-I and HLA-II peptides, respectively, that were derived from 41 species of bacteria. We identified recurrent bacterial peptides in tumours from different patients, as well as in different tumours from the same patient. Our study reveals that peptides derived from intracellular bacteria can be presented by tumour cells and elicit immune reactivity, and thus provides insight into a mechanism by which bacteria influence activation of the immune system and responses to therapy.

PhISCS-BnB: a fast branch and bound algorithm for the perfect tumor phylogeny reconstruction problem

MOTIVATION

Recent advances in single-cell sequencing (SCS) offer an unprecedented insight into tumor emergence and evolution. Principled approaches to tumor phylogeny reconstruction via SCS data are typically based on general computational methods for solving an integer linear program, or a constraint satisfaction program, which, although guaranteeing convergence to the most likely solution, are very slow. Others based on Monte Carlo Markov Chain or alternative heuristics not only offer no such guarantee, but also are not faster in practice. As a result, novel methods that can scale up to handle the size and noise characteristics of emerging SCS data are highly desirable to fully utilize this technology.

RESULTS

We introduce PhISCS-BnB (phylogeny inference using SCS via branch and bound), a branch and bound algorithm to compute the most likely perfect phylogeny on an input genotype matrix extracted from an SCS dataset. PhISCS-BnB not only offers an optimality guarantee, but is also 10-100 times faster than the best available methods on simulated tumor SCS data. We also applied PhISCS-BnB on a recently published large melanoma dataset derived from the sublineages of a cell line involving 20 clones with 2367 mutations, which returned the optimal tumor phylogeny in <4 h. The resulting phylogeny agrees with and extends the published results by providing a more detailed picture on the clonal evolution of the tumor.

AVAILABILITY AND IMPLEMENTATION

https://github.com/algo-cancer/PhISCS-BnB.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Anti-tumour immunity induces aberrant peptide presentation in melanoma

Extensive tumour inflammation, which is reflected by high levels of infiltrating T cells and interferon-γ (IFNγ) signalling, improves the response of patients with melanoma to checkpoint immunotherapy^1,2. Many tumours, however, escape by activating cellular pathways that lead to immunosuppression. One such mechanism is the production of tryptophan metabolites along the kynurenine pathway by the enzyme indoleamine 2,3-dioxygenase 1 (IDO1), which is induced by IFNγ^3-5. However, clinical trials using inhibition of IDO1 in combination with blockade of the PD1 pathway in patients with melanoma did not improve the efficacy of treatment compared to PD1 pathway blockade alone^6,7, pointing to an incomplete understanding of the role of IDO1 and the consequent degradation of tryptophan in mRNA translation and cancer progression. Here we used ribosome profiling in melanoma cells to investigate the effects of prolonged IFNγ treatment on mRNA translation. Notably, we observed accumulations of ribosomes downstream of tryptophan codons, along with their expected stalling at the tryptophan codon. This suggested that ribosomes bypass tryptophan codons in the absence of tryptophan. A detailed examination of these tryptophan-associated accumulations of ribosomes-which we term 'W-bumps'-showed that they were characterized by ribosomal frameshifting events. Consistently, reporter assays combined with proteomic and immunopeptidomic analyses demonstrated the induction of ribosomal frameshifting, and the generation and presentation of aberrant trans-frame peptides at the cell surface after treatment with IFNγ. Priming of naive T cells from healthy donors with aberrant peptides induced peptide-specific T cells. Together, our results suggest that IDO1-mediated depletion of tryptophan, which is induced by IFNγ, has a role in the immune recognition of melanoma cells by contributing to diversification of the peptidome landscape.

Focal Areas of High Signal Intensity in Children with Neurofibromatosis Type 1: Expected Evolution on MRI

BACKGROUND AND PURPOSE

Focal areas of high signal intensity are T2WI/T2-FLAIR hyperintensities frequently found on MR imaging of children diagnosed with neurofibromatosis type 1, often thought to regress spontaneously during adolescence or puberty. Due to the risk of tumor in this population, some focal areas of high signal intensity may pose diagnostic problems. The objective of this study was to assess the characteristics and temporal evolution of focal areas of high signal intensity in children with neurofibromatosis type 1 using long-term follow-up with MR imaging.

MATERIALS AND METHODS

We retrospectively examined the MRIs of children diagnosed with neurofibromatosis type 1 using the National Institutes of Health Consensus Criteria (1987), with imaging follow-up of at least 4 years. We recorded the number, size, and surface area of focal areas of high signal intensity according to their anatomic distribution on T2WI/T2-FLAIR sequences. A generalized mixed model was used to analyze the evolution of focal areas of high signal intensity according to age, and separate analyses were performed for girls and boys.

RESULTS

Thirty-nine patients (ie, 285 MR images) with a median follow-up of 7 years were analyzed. Focal areas of high signal intensity were found in 100% of patients, preferentially in the infratentorial white matter (35% cerebellum, 30% brain stem) and in the capsular lenticular region (22%). They measured 15 mm in 95% of cases. They appeared from the age of 1 year; increased in number, size, and surface area to a peak at the age of 7; and then spontaneously regressed by 17 years of age, similarly in girls and boys.

CONCLUSIONS

Focal areas of high signal intensity are mostly small (<15 mm) abnormalities in the posterior fossa or capsular lenticular region. Our results suggest that the evolution of focal areas of high signal intensity is not related to puberty with a peak at the age of 7 years. Knowledge of the predictive evolution of focal areas of high signal intensity is essential in the follow-up of children with neurofibromatosis type 1.

[Toward a preventive management Alzheimer's disease]

Les démences et la maladie d’Alzheimer (MA), en particulier, vont devenir de plus en plus un enjeu de santé publique. Trois données importantes peuvent cependant modifier le poids de ces pathologies : (1) de simples mesures d’hygiène de vie (contrôle de facteurs de risque vasculaire, activité physique et stimulation cognitive) instaurées chez les jeunes adultes ont un impact sur un déclin cognitif ultérieur ; (2) chez des sujets âgés à risque, ces mêmes dispositions retardent l’entrée dans la maladie et (3) enfin et pour la première fois, un anticorps anti-amyloïde aurait montré un effet significatif sur l’évolution de la MA chez des patients au stade débutant. Il ressort de ces travaux qu’il faut se préparer à reconsidérer la stratégie de prise en charge des troubles cognitifs, qu’ils soient mineurs ou majeurs, et de la MA en particulier. L’entrée des patients dans le parcours de soins reste aujourd’hui trop tardive. La solution est d’agir plus précocement, voire de façon préventive. Il faut développer une offre de soins adaptée à cette situation nouvelle afin d’agir sur la maladie le plus tôt possible, fondée sur : 1) des algorithmes prédictifs pour déterminer chez les sujets sans symptômes spécifiques ceux qui seront à risque de développer une pathologie dégénérative; ces algorithmes devront être mis au point à partir de données démographiques, familiales, cognitives, génomiques et biologiques, comme celles recueillies dans le projet « Santé-Cerveau » développé en partenariat avec l’ARS et les médecins généralistes ; 2) le renforcement des activités de prévention dans les 450 centres mémoire de proximité disponibles en France et les 26 CM2R et 3) la transformation de quelques-uns de ces centres experts en « cliniques de prévention de la démence » pour tester les mesures de prévention, initier des programmes d’éducation thérapeutique multidomaine et les valider, communiquer sur le risque, répondre à la demande de sujets inquiets et déterminer, chez ceux-ci, à l’aide des algorithmes, le niveau de risque qu’ils ont de déclarer une MA dans les mois et années qui viennent, en tenant compte de la compétition entre les risques. On peut ainsi se préparer à faire bénéficier précocement les uns et les autres des traitements pharmacologiques susceptibles d’exister.

A85 COLON CANCER SCREENING IN PATIENTS ASSESSED FOR LUNG TRANSPLANTATION

Background

Colorectal Cancer (CRC) mortality is significantly higher after a lung transplant (1). CRC screening for average risk patients in British Columbia is done with Fecal Immunochemical Testing (FIT) every two years (2), however colonoscopy is currently the standard modality in patients undergoing lung transplant assessments in British Columbia. The yield of using FITs or Fecal Occult Blood Testing (FOBT) and colonoscopy in screening for lung transplant assessments in Canada is unknown.

Aims

To review the colon cancer screening results for all lung transplants done in British Columbia from 2013 to 2018.

Methods

This is a retrospective chart review of the 222 lung transplants done from January 2013 to December 2019.

Results

220 patients were transplanted during this time period. 2 patients were re-transplanted. 136 of the 220 lung transplant patients were male (62%). The most common indication for transplantation was interstitial lung disease (44%), followed by chronic obstructive pulmonary disease (30%), cystic fibrosis (7%), and pulmonary hypertension (4%). Colonoscopies were performed in 127 of the 220 patients. Computed tomography (CT) colonography was performed in 15 of the 220 patients, and a FOBT or FIT was performed in 200 of the 220 patients. No colon cancers were found by colonoscopy or CT colonography (0/142). Of the colonoscopies performed, 38 % (49/127) had adenomatous or serrated polyps removed. Of these 36% (18/49) had high risk pathology. The positive predictive value of a FIT/FOBT positive for a polyp was 51.4 % (CI 37.6–65.1%).

Conclusions

The value of non-invasive screening modalities in pre-lung transplant patients are modest. Program screening should be tailored to the lung transplant candidate’s risk of CRC and the risk of an invasive procedure with a known complication rate.

Funding Agencies

None

Incidental Brain MRI Findings in Children: A Systematic Review and Meta-Analysis

BACKGROUND

The detection of incidental findings on children's brain MR imaging poses various practical issues because the life-long implications of such findings may be profound.

PURPOSE

Our aim was to assess the prevalence and characteristics of incidental brain MR imaging findings in children.

DATA SOURCES

Electronic databases (PubMed, EMBASE, and Cochrane) were searched for articles published between 1985 to July 2018, with the following search terms: "incidental," "findings," "brain," "MR imaging."

STUDY SELECTION

Inclusion criteria were the following: 1) patients younger than 21 years of age, 2) healthy children without any clinical condition, 3) MR images obtained with at least a 1.5T magnet, 4) original articles, and 5) a methodologic quality score of ≥10.

DATA ANALYSIS

Two observers independently extracted data and assessed data quality and validity. The number and type of incidental findings were pooled. Heterogeneity was assessed using the Cochran Q statistic and the I² statistic.

DATA SYNTHESIS

Seven studies were included, reporting 5938 children (mean age, 11.3 ± 2.8 years). Incidental findings were present in 16.4% (99% CI, 9.8-26.2; Q = 117.5, I²= 94.9%) of healthy children, intracranial cysts being the most frequent (10.2%, 99% CI, 3.1-28.5; Q = 306.4, I² = 98.0%). Nonspecific white matter hyperintensities were reported in 1.9% (99% CI, 0.2-16.8; Q = 73.6, I² = 94.6%), Chiari 1 malformation was found in 0.8% (99% CI, 0.5-1.3; Q = 7.6, I² = 60.5%), and intracranial neoplasms were reported in 0.2% (99% CI, 0.1-0.6; Q = 3.4, I² = 12.3%). In total, the prevalence of incidental findings needing follow-up was 2.6% (99% CI, 0.5-11.7; Q = 131.2, I² = 95.4%). Incidental findings needing specific treatment were brain tumors (0.2%) and cavernomas (0.2%).

LIMITATIONS

Limitations were no age stratification or ethnicity data and variation in the design of included studies.

CONCLUSIONS

The prevalence of incidental findings is much more frequent in children than previously reported in adults, but clinically meaningfull incidental findings were present in <1 in 38 children.

Congenital syphilis: A prospective study of 22 cases diagnosed by PCR

Congenital syphilis (CS) is caused by Treponema pallidum infection in utero. There is a need to develop new tools to diagnose CS: the diagnostic value of PCR is difficult to assess. The aim of this study was to describe the clinical and laboratory characteristics of mothers and infants with CS as diagnosed by PCR tests on various maternal and neonatal samples.

PATIENTS AND METHODS

We included all infants epidemiologically linked to a mother diagnosed with syphilis whose samples were referred to the Syphilis Reference Center, and for whom at least one positive PCR result was obtained.

RESULTS

Twenty-two mother-infant pairs (8.3%) with assay performed on samples from one to four different anatomic sites were included between February 2011 and April 2018. Seven mothers (31.8%) were born abroad, fifteen (68.2%) presented psychological and/or social problems, eight (36.4%) had not been screened for syphilis prior to delivery, and eleven (50%) were referred from French overseas departments or territories, or from the Paris region. Six infants (27.3%) were stillborn and six were born preterm, while fifteen infants (68.2%) presented clinical features of CS. All infants born preterm were symptomatic. Infant VDRL/RPR titer was no greater than four times that in the mother's serum, except in two cases.

DISCUSSION

Lack of antenatal care, social disadvantage and psychological issues were common. There is a need for enhanced surveillance both in the French overseas departments/territories and in the Paris region. A larger study is required to assess the sensitivity and specificity of PCR. The best site for sampling has yet to be established. We recommend the collection of as many samples as possible to avoid underdiagnosis of CS.

UVB-Induced Tumor Heterogeneity Diminishes Immune Response in Melanoma

Although clonal neo-antigen burden is associated with improved response to immune therapy, the functional basis for this remains unclear. Here we study this question in a novel controlled mouse melanoma model that enables us to explore the effects of intra-tumor heterogeneity (ITH) on tumor aggressiveness and immunity independent of tumor mutational burden. Induction of UVB-derived mutations yields highly aggressive tumors with decreased anti-tumor activity. However, single-cell-derived tumors with reduced ITH are swiftly rejected. Their rejection is accompanied by increased T cell reactivity and a less suppressive microenvironment. Using phylogenetic analyses and mixing experiments of single-cell clones, we dissect two characteristics of ITH: the number of clones forming the tumor and their clonal diversity. Our analysis of melanoma patient tumor data recapitulates our results in terms of overall survival and response to immune checkpoint therapy. These findings highlight the importance of clonal mutations in robust immune surveillance and the need to quantify patient ITH to determine the response to checkpoint blockade.

CT and Multimodal MR Imaging Features of Embryonal Tumors with Multilayered Rosettes in Children

BACKGROUND AND PURPOSE

Embryonal tumors with multilayered rosettes, C19MC-altered, are brain tumors occurring in young children, which were clearly defined in the 2016 World Health Organization classification of central nervous system neoplasms. Our objective was to describe the multimodal imaging characteristics of this new entity.

MATERIALS AND METHODS

We performed a retrospective monocentric review of embryonal brain tumors and looked for embryonal tumors with multilayered rosettes with confirmed C19MC alteration. We gathered morphologic imaging data, as well as DWI and PWI data (using arterial spin-labeling and DSC).

RESULTS

We included 16 patients with a median age of 2 years 8 months. Tumors were both supratentorial (56%, 9/16) and infratentorial (44%, 7/16). Tumors were large (median diameter, 59 mm; interquartile range, 48-71 mm), with absent (75%, 12/16) or minimal (25%, 4/16) peritumoral edema. Enhancement was absent (20%, 3/15) or weak (73%, 11/15), whereas intratumoral macrovessels were frequently seen (94%, 15/16) and calcifications were present in 67% (10/15). Diffusion was always restricted, with a minimal ADC of 520 mm²/s (interquartile range, 495-540 mm²/s). Cerebral blood flow using arterial spin-labeling was low, with a maximal CBF of 43 mL/min/100 g (interquartile range, 33-55 mL/min/100 g 5). When available (3 patients), relative cerebral blood volume using DSC was high (range, 3.5-5.8).

CONCLUSIONS

Embryonal tumors with multilayered rosettes, C19MC-altered, have characteristic imaging features that could help in the diagnosis of this rare tumor in young children.

Author Correction: RGS7 is recurrently mutated in melanoma and promotes migration and invasion of human cancer cells

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Correction to: Diffusion tensor imaging (DTI) and Tractography of the spinal cord in pediatric population with spinal lipomas: preliminary study

The article which was recently published contained error. The figures and figure captions were interchanged during the publication process of the paper.

[Impact of air quality on practices and results in the IVF laboratory]

The concept of Air Quality often refers to particulate and microbiological contamination of ambiant air. European Directive 2006/86/CE encompass the IVF process and specify a class A air quality for manipulation of tissue and cells, in a class D environment (A over D rule). Recognizing the paramount importance of ensuring the highest microbiological and particulate safety in the IVF laboratory, it is equally important to take into account practicability issues and the financial burden of these recommendations, as well as the utter need to protect gametes and embryo viability during their IVF journey. The usefulness of such stringent recommendations may also be questionned given the absence of published cases of airborne contaminations and related patients infections after embryo transfer. The European directive stems from pharmaceutical standards and were not specifically designed for human IVF. Gametes and embryos are indeed extremely sensitive to physical and chemical stress and require strict temperature, osmolarity and pH control, as well as an absence of chemical contamination during manipulation and culture. These conditions are hardly obtained when using laminar flow hoods. Following concerns raised by many experts in the field, exceptions to the A over D rule were added in the 2006/86/CE Directives. This narrative review discusses all these aspects in a critical way and compare scientific and legal requirements applying to IVF practices in different regions of the world.

Combined Analysis of Antigen Presentation and T-cell Recognition Reveals Restricted Immune Responses in Melanoma

The quest for tumor-associated antigens (TAA) and neoantigens is a major focus of cancer immunotherapy. Here, we combine a neoantigen prediction pipeline and human leukocyte antigen (HLA) peptidomics to identify TAAs and neoantigens in 16 tumors derived from seven patients with melanoma and characterize their interactions with their tumor-infiltrating lymphocytes (TIL). Our investigation of the antigenic and T-cell landscapes encompassing the TAA and neoantigen signatures, their immune reactivity, and their corresponding T-cell identities provides the first comprehensive analysis of cancer cell T-cell cosignatures, allowing us to discover remarkable antigenic and TIL similarities between metastases from the same patient. Furthermore, we reveal that two neoantigen-specific clonotypes killed 90% of autologous melanoma cells, both in vitro and in vivo, showing that a limited set of neoantigen-specific T cells may play a central role in melanoma tumor rejection. Our findings indicate that combining HLA peptidomics with neoantigen predictions allows robust identification of targetable neoantigens, which could successfully guide personalized cancer immunotherapies.Significance: As neoantigen targeting is becoming more established as a powerful therapeutic approach, investigating these molecules has taken center stage. Here, we show that a limited set of neoantigen-specific T cells mediates tumor rejection, suggesting that identifying just a few antigens and their corresponding T-cell clones could guide personalized immunotherapy. Cancer Discov; 8(11); 1366-75. ©2018 AACR. This article is highlighted in the In This Issue feature, p. 1333.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Imaging features of medulloblastoma: Conventional imaging, diffusion-weighted imaging, perfusion-weighted imaging, and spectroscopy: From general features to subtypes and characteristics

Medulloblastoma is a frequent high-grade neoplasm among pediatric brain tumours. Its classical imaging features are a midline tumour growing into the fourth ventricle, hyperdense on CT-scan, displaying a hypersignal when using diffusion-weighted imaging, with a variable contrast enhancement. Nevertheless, atypical imaging features have been widely reported, varying according to the age of the patient, and histopathological subtype. In this study, we review the classical and atypical imaging features of medulloblastomas, with emphasis on advanced MRI techniques, histopathological and molecular subtypes and characteristics, and follow-up modalities.

Urea Cycle Dysregulation Generates Clinically Relevant Genomic and Biochemical Signatures

The urea cycle (UC) is the main pathway by which mammals dispose of waste nitrogen. We find that specific alterations in the expression of most UC enzymes occur in many tumors, leading to a general metabolic hallmark termed "UC dysregulation" (UCD). UCD elicits nitrogen diversion toward carbamoyl-phosphate synthetase2, aspartate transcarbamylase, and dihydrooratase (CAD) activation and enhances pyrimidine synthesis, resulting in detectable changes in nitrogen metabolites in both patient tumors and their bio-fluids. The accompanying excess of pyrimidine versus purine nucleotides results in a genomic signature consisting of transversion mutations at the DNA, RNA, and protein levels. This mutational bias is associated with increased numbers of hydrophobic tumor antigens and a better response to immune checkpoint inhibitors independent of mutational load. Taken together, our findings demonstrate that UCD is a common feature of tumors that profoundly affects carcinogenesis, mutagenesis, and immunotherapy response.

Associations of ultra-processed food and drink products with asthma and wheezing among Brazilian adolescents

BACKGROUND

Although both consumptions of ultra-processed products and asthma are common during adolescence, the epidemiological evidence in regarding their association is unclear. We investigated the associations of ultra-processed products consumption with asthma and wheezing in a representative sample of Brazilian adolescents.

METHODS

We used data from a representative sample of 109 104 Brazilian adolescents enrolled in the National Survey of School Health, 2012. The consumption of ultra-processed products was based on the weekly consumption (0-2, 3-4, ≥5 d/wk) of sweet biscuits, salty biscuits, ultra-processed meats, sweets/candies, soft drinks, and packaged snacks over the previous 7 days. We also calculated an ultra-processed consumption score by adding partial scores corresponding to weekly frequency intake of each ultra-processed product. The ultra-processed consumption score ranged from 0 to 42, the higher score, the higher the intake of these products. The presence of wheezing in the previous 12 months and asthma at any time in the past was self-reported.

RESULTS

The adjusted odds ratios of asthma comparing the extreme categories ranged from 1.08 (95% CI 1.03-1.13) for sweets/candies to 1.30 (1.21-1.40) for ultra-processed meats. Similar magnitude of associations was found for wheezing outcome. The ultra-processed consumption score was positively associated with the presence of asthma and wheezing in a dose-response manner. The adjusted OR of asthma and wheezing comparing highest to lowest quintile of ultra-processed consumption score was 1.27 (95% CI 1.15-1.41) and 1.42 (1.35-1.50), respectively.

CONCLUSIONS

The consumption of ultra-processed products was positively associated with the presence of asthma and wheezing in adolescents.

Impact of California Fires on Local and Regional Air Quality: The Role of a Low-Cost Sensor Network and Satellite Observations

PM2.5, or fine particulate matter, is a category of air pollutant consisting of particles with effective aerodynamic diameter equal to or less than 2.5 μm. These particles have been linked to human health impacts as well as regional haze, visibility, and climate change issues. Due to cost and space restrictions, the U.S. Environmental Protection Agency monitoring network remains spatially sparse. To increase the spatial resolution of monitoring, previous studies have used satellite data to estimate ground-level PM concentrations, despite these estimates being associated with moderate to large uncertainties when relating a column measure of aerosol (aerosol optical depth) with surface measurements. To this end, we discuss a low-cost air quality monitor (LCAQM) network deployed in California. In this study, we present an application of LCAQM and satellite data for quantifying the impact of wildfires in California during October 2017. The impacts of fires on PM2.5 concentration at varying temporal (hourly, daily, and weekly) and spatial (local to regional) scales have been evaluated. Comparison between low-cost air quality sensors and reference-grade air quality instruments shows expected performance with moderate to high uncertainties. The LCAQM measurements, in the absence of federal equivalent method data, were also found to be very useful in developing statistical models to convert aerosol optical depth into PM2.5 with performance of satellite-derived PM2.5, similar to that obtained using the federal equivalent method data. This paper also highlights challenges associated with both LCAQM and satellite-based PM2.5 measurements, which require further investigation and research.

RGS7 is recurrently mutated in melanoma and promotes migration and invasion of human cancer cells

Analysis of 501 melanoma exomes revealed RGS7, which encodes a GTPase-accelerating protein (GAP), to be a tumor-suppressor gene. RGS7 was mutated in 11% of melanomas and was found to harbor three recurrent mutations (p.R44C, p.E383K and p.R416Q). Structural modeling of the most common recurrent mutation of the three (p.R44C) predicted that it destabilizes the protein due to the loss of an H-bond and salt bridge network between the mutated position and the serine and aspartic acid residues at positions 58 as 61, respectively. We experimentally confirmed this prediction showing that the p.R44C mutant protein is indeed destabilized. We further show RGS7 p.R44C has weaker catalytic activity for its substrate Gα_o, thus providing a dual mechanism for its loss of function. Both of these effects are expected to contribute to loss of function of RGS7 resulting in increased anchorage-independent growth, migration and invasion of melanoma cells. By mutating position 56 in the R44C mutant from valine to cysteine, thereby enabling the formation of a disulfide bridge between the two mutated positions, we slightly increased the catalytic activity and reinstated protein stability, leading to the rescue of RGS7′s function as a tumor suppressor. Our findings identify RGS7 as a novel melanoma driver and point to the clinical relevance of using strategies to stabilize the protein and, thereby, restore its function.

Eustachian tube dysfunction leading to middle-ear pathology in patients on chronic mechanical ventilation

OBJECTIVE

This study aimed to investigate the prevalence of and risk factors for Eustachian tube dysfunction leading to middle-ear pathology in patients on chronic mechanical ventilation via tracheostomy tube.

METHODS

A total of 40 patients on chronic ventilation were included in a prospective cohort study. Middle-ear status was determined by tympanometry. Tympanograms were categorised as types A, B or C; types B and C were defined as middle-ear pathology.

RESULTS

In all, 57 ears of 40 patients were examined. Disease was found in at least 1 ear in 26 out of 40 patients. Middle-ear pathology was found in 25 out of 34 patients who were tube fed (via nasogastric tube or percutaneous endoscopic gastrostomy) vs 1 patient out of the 6 fed orally (p = 0.014), and in 23 out of 31 with conscious or cognitive impairment vs 3 out of 9 cognitively intact patients (p = 0.044).

CONCLUSION

Middle-ear pathology is common in patients on chronic mechanical ventilation via tracheostomy tube. The highest prevalence was in those with impaired consciousness or cognition, and oral feeding appeared protective.