Identification, validation and biological characterisation of novel glioblastoma tumour microenvironment subtypes: implications for precision immunotherapy.

BACKGROUND: New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles have failed to direct treatment strategies. We hypothesised that interrogation of the GBM tumour microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision immunotherapy treatment strategies. MATERIALS AND METHODS: A refined and validated microenvironment cell population (MCP) counter method was applied to >800 GBM patient tumours (GBM-MCP-counter). Specifically, partition around medoids (PAM) clustering of GBM-MCP-counter scores in the GLIOTRAIN discovery cohort identified three novel patient clusters, uniquely characterised by TME composition, functional orientation markers and immune checkpoint proteins. Validation was carried out in three independent GBM-RNA-seq datasets. Neoantigen, mutational and gene ontology analysis identified mutations and uniquely altered pathways across subtypes. The longitudinal Glioma Longitudinal AnalySiS (GLASS) cohort and three immunotherapy clinical trial cohorts [treatment with neoadjuvant/adjuvant anti-programmed cell death protein 1 (PD-1) or PSVRIPO] were further interrogated to assess subtype alterations between primary and recurrent tumours and to assess the utility of TME classifiers as immunotherapy biomarkers. RESULTS: TMEHigh tumours (30%) displayed elevated lymphocyte, myeloid cell immune checkpoint, programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 transcripts. TMEHigh/mesenchymal+ patients featured tertiary lymphoid structures. TMEMed (46%) tumours were enriched for endothelial cell gene expression profiles and displayed heterogeneous immune populations. TMELow (24%) tumours were manifest as an 'immune-desert' group. TME subtype transitions upon recurrence were identified in the longitudinal GLASS cohort. Assessment of GBM immunotherapy trial datasets revealed that TMEHigh patients receiving neoadjuvant anti-PD-1 had significantly increased overall survival (P = 0.04). Moreover, TMEHigh patients treated with adjuvant anti-PD-1 or oncolytic virus (PVSRIPO) showed a trend towards improved survival. CONCLUSIONS: We have established a novel TME-based classification system for application in intracranial malignancies. TME subtypes represent canonical 'termini a quo' (starting points) to support an improved precision immunotherapy treatment approach.

Assessment of measurement methods of posterior inflammation in stromal choroiditis: the value of quantitative outcome measures versus the presently qualitatively based paradigm.

PURPOSE: To assess posterior inflammation using a fluorescein (FA)/indocyanine-green angiography (ICGA) scoring system, and compare them to the presently recommended outcome measure, the standardization of uveitis nomenclature vitreous haze score (SUN-VH) in stromal choroiditis. METHODS: This was a retrospective study on patients with a diagnosis of ocular sarcoidosis(OS), ocular tuberculosis(OT), Birdshot retinochoroiditis(BRC) and Vogt-Koyanagi-Harada disease(VKH) seen in the Centre for Ophthalmic Specialized Care, Lausanne, Switzerland. Angiography signs were quantified according to an established FA/ICGA scoring system. Vitritis was assessed using SUN-VH. Results were compared. RESULTS: 65 newly diagnosed patients (128 eyes) with stromal choroiditis were included. Angiographic scoring showed variable degrees of choroidal versus retinal involvement (87% for OS, 72% for OT, 62.5% for BRC and 100% for VKH). On the other hand, a mere 22 of 128 eyes (17%) showed a SUN-VH score ≥ 2 necessary for inclusion in clinical trials. Moreover, FA/ICGA values followed a normal distribution curve and presented inter-examiner variations greater than 1-SD in only 8.4% of cases. SUN-VH values' distribution was non-normal and showed inter-examiner discrepancies greater than 1-SD in 51.7% of cases. CONCLUSION: This study highlights the precise measurement of global posterior inflammation achieved by a dual FA/ICGA scoring system in stromal choroiditis. In contrast, SUN-VH scale appears imprecise and inadequate, as only a minute percentage of the studied eyes could have been included in a clinical trial based on this criterion. To evaluate posterior intraocular inflammation meaningfully in stromal choroiditis, the use of dual FA/ICGA is strongly advised and should replace the presently recommended SUN-VH system.

Observation of intrinsically bright terrestrial gamma ray flashes from the Mediterranean basin.

We present three terrestrial gamma ray flashes (TGFs) observed over the Mediterranean basin by the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) satellite. Since the occurrence of these events in the Mediterranean region is quite rare, the characterization of the events was optimized by combining different approaches in order to better define the cloud of origin. The TGFs on 7 November 2004 and 16 October 2006 came from clouds with cloud top higher than 10-12 km where often a strong penetration into the stratosphere is found. This kind of cloud is usually associated with heavy precipitation and intense lightning activity. Nevertheless, the analysis of the cloud type based on satellite retrievals shows that the TGF on 27 May 2004 was produced by an unusual shallow convection. This result appears to be supported by the model simulation of the particle distribution and phase in the upper troposphere. The TGF on 7 November 2004 is among the brightest ever measured by RHESSI. The analysis of the energy spectrum of this event is consistent with a production altitude ≤12 km, which is in the upper part of the cloud, as found by the meteorological analysis of the TGF-producing thunderstorm. This event must be unusually bright at the source in order to produce such a strong signal in RHESSI. We estimate that this TGF must contain ∼3 × 1018 initial photons with energy >1 MeV. This is 1 order of magnitude brighter than earlier estimations of an average RHESSI TGF.