Identification of Excellent Prognosis IDH Wildtype Glioblastomas Using Genomic and Metabolic Profiling

PURPOSE/OBJECTIVE(S)

High grade gliomas (HGGs) are aggressive brain tumors with altered cellular metabolism. HGGs can carry mutations in the tricarboxylic acid (TCA) cycle enzyme isocitrate dehydrogenase 1 (IDH1), conferring distinct biology and improved patient prognosis compared to IDH wildtype (wt) tumors. Using metabolomic analyses of tumor tissue, we previously showed that IDH wt and IDH mutant (IDH mut) tumors have unique metabolomic signatures that correlate with different survival outcomes. Among this cohort of 69 HGG samples, we identified two unique patient tumors that metabolically clustered with IDH mut tumors, but lacked both the IDH mutation and its product 2-hydroxyglutarate. We aimed to discover unique mutations in these two tumors that may impart an IDH mutant-like phenotype in the absence of an IDH1 or IDH2 mutation.

MATERIALS/METHODS

Whole exome sequencing (WES) was performed on frozen tumor samples from two patients diagnosed as glioblastoma (GBM), IDH wt via Agilent v5 + IncRNA platform. Alignment to the hg38 genome and variant calling were completed using an accelerated implementation of GATK's BWA and MuTect2 algorithms from Sentieon. Variants were filtered based on supporting reads and variant allele thresholds, with synonymous variants and common SNPs removed. High-confidence variants were further filtered by membership in the four KEGG pathways associated with IDH1 and IDH2. Identified variants were corroborated with metabolomics data from the two unique IDH wt tumors compared with classical GBM IDH wt, oligodendrogliomas IDH mut and astrocytomas IDH mut to identify putative drivers of an IDH mutant-like metabolomic phenotype in these unique IDH wt tumors.

RESULTS

Despite the lack of an IDH mutation, one patient survived 45.6 months and the other patient remains alive at last follow up 64 months post diagnosis, much longer than the 16-18-month median survival typical of patients with GBM IDH wt. WES of outlier IDH wt tumor samples revealed 65 unique mutations in the queried KEGG pathways, of which 34 had a variant allele frequency > = 0.15. These variants were processed in Gprofiler, confirming expected enrichment of the carboxylic acid metabolic biologic process, a functional gene set consisting of TCA genes, among these variants (p = 0.002, 3.6-fold enrichment). Accordingly, metabolite levels of intermediates of the TCA cycle, including malate and isocitrate were decreased in the outlier tumor samples compared to classic GBMs IDH wt (p<0.001). Presence of genetic alterations in key variants of the carboxylic acid metabolic biologic process (including ME1, GYP4F3, PTGIS, PFKL, PSPH, AKR1A1, HK2, NOS1) correlated with improved overall survival among GBM patients in the TCGA (p = 0.04). Laboratory validation of these findings in preclinical GBM models is ongoing.

CONCLUSION

Disruption of the TCA cycle independent of an IDH mutation is associated with favorable survival in GBM. Pharmacologic inhibition of these pathways may be a promising strategy to improve GBM outcomes.

Intravascular lithotripsy during percutaneous coronary intervention for calcified coronary lesions: analysis of patient and procedural characteristics and clinical outcomes

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Coronary artery calcification is frequently encountered during percutaneous coronary intervention (PCI). It can reduce PCI success and increase intra-procedural and post-procedural complications, including stent embolization, under-expansion and mal-apposition. Intravascular lithotripsy (IVL) is a new tool developed to treat calcified coronary lesions.

Purpose

Retrospective analysis of all cases of intravascular lithotripsy performed within our local health district to examine patient and procedural characteristics and clinical outcomes.

Methods

All patients undergoing PCI with intravascular lithotripsy between September 2019-August 2021 within our local health district were analysed. Patient and procedural characteristics and clinical outcomes were recorded.

Results

67 patients (50 men) were included with mean age 71.4 ± 8.7years. Risk factors prevalence included smoking (34%), hypertension (82%), dyslipidaemia (69%) and diabetes (46%). Trans-radial artery access was used in 38 patients (57%). IVL was performed most commonly in the left anterior descending artery (52%),[Figure 1]. IVL was utilised in 9 chronic total occlusions and 12 bifurcation lesions. Intracoronary (IC) imaging was performed in 59 patients (88%), intravascular ultrasound in 41(61%) and optical coherence tomography in 18 (27%). 41 (69%) patients had imaging performed pre and post IVL and post PCI.  IC imaging identified 14 cases with 270º calcification arc and 45 cases with 360º arc. Nine cases (13.4%) required rotational atherectomy prior to IVL (most commonly 1.75mm burr). Mean reference vessel diameter was 3.2 ± 0.3mm. Mean lesion length was 36.3 ± 16.5mm. Mean pre-PCI stenosis was 85.5 ± 10.8%. Drug eluting stents were successfully deployed in 57 cases (85%), 10 had balloon angioplasty alone. Mean stent length was 39.2 ± 17.8mm. Mean post-PCI stenosis was 4.5 ± 13.3% (median 0%). Figure 2 shows a statistically significant increase in minimum lumen diameter and minimum lumen area post-IVL and minimal-stent-area (MSA) post-PCI. Mean stent expansion was 83%. Mean screening time 35.8 ± 17.8 minutes with mean contrast used 207.3 ± 78.7mL. No sustained arrhythmias or side-branch loss occurred. Vessel rupture was recorded in one patient necessitating urgent cardiac surgery (due to oversized balloon) and in 4 cases the IVL balloon could not cross the lesion.

Conclusion

Our experience shows that IVL is safe and effective and facilitates stent delivery and expansion. Intracoronary imaging is important to determine the need for calcium modification and evaluate its success prior to stent delivery and to confirm optimised stent expansion. Abstract Figure. Breakdown of PCI Artery  Abstract Figure. IC Dimensions Pre/Post IVL/Post PCI

P2Y12 pre-treatment for NSTE-ACS in a tertiary hospital centre: real world compliance experience with ESC 2020 guidelines

Funding Acknowledgements

Type of funding sources: None.

Background

The 2020 ESC guidelines for managing NSTE-ACS recommend against routine pre-treatment with a P2Y12 receptor inhibitor if coronary anatomy is not known and an early (&lt;24h) invasive management is planned. With delayed (&gt;24h) invasive management, pre-treatment may be considered in selected cases.

Purpose

Evaluate antiplatelet pre-treatment practices for NSTE-ACS in a tertiary cardiology centre in Australia.

Methods

Retrospective analysis of NSTE-ACS cases from January to August 2021 were obtained from the cardiac laboratory database. Patients on a P2Y12 inhibitor prior to presentation were excluded. Clinical, demographic, angiographic and medication data were obtained from the electronic database.

Results

85 cases were included. Mean age was 62 ± 11.5 and 81% were male. The prevalence of hypertension, hypercholesterolaemia, type 2 diabetes and active smoking was 54.8%, 51.2%, 38.1% and 34.5% respectively. Mean time to angiography was 1.7 ± 1.4 days and the median peak pre-procedural troponin T was 191.5 (80 to 852). Access was predominantly radial (84.5%) with the remainder femoral (15.5%).

Angiographic findings included, obstructive disease amenable to percutaneous coronary intervention (50.0%), obstructive disease for surgical revascularisation (22.6%), and non-obstructive disease (27.4%). The mean time from angiography to surgical revascularisation was 6.4 ± 4.4 days. Three patients (3.6%) had bleeding [managed conservatively], specifically upper limb haematoma, groin haematoma, and haemoptysis.

The majority of patients (79.8%) received P2Y12 inhibitors (40.5% clopidogrel and 39.3% ticagrelor) prior to angiography. Of these, 49.3% had percutaneous angioplasty, 17.9% had surgical revascularisation and 32.8% had non-obstructive disease (managed with single antithrombotic agent). Of those who did not receive P2Y12 inhibitors [n = 17, 20.2%]. Of these, 53% had percutaneous angioplasty, 40% had surgical revascularisation, and 5% had non-obstructive disease.

Conclusions

Overall, pre-treatment with a P2Y12 inhibitor was still very common, risking delays to bypass surgery and increasing bleeding. Practice did not generally align with contemporary ESC 2020 guidelines. Understanding the reasons for guideline non-compliance would be important for optimising treatments. Education for emergency and cardiology staff as well as creation of local practice policies may help increase compliance with evidence-based guidelines.

Monitoring of Hemostasis Parameters During Coronary Thrombolysis with Recombinant Tissue-Type Plasminogen Activator

The monitoring of changes in the blood coagulation and fibrinolytic systems during thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA) may be complicated by artifacts due to in vitro activation after blood collection and to interference of other agents (e. g., heparin) in the assays. In 106 patients with early acute myocardial infarction, infused with 150 mg of rt-PA (G11044) intravenously over 5 to 8 hours, blood samples were collected into liquid citrate supplemented with the plasmin inhibitor aprotinin (200 KlU/ml plasma) or on a lyophilized mixture of acidified citrate and the synthetic t-PA inhibitor D-Phe-Pro-Arg-CH2Cl (PPACK). A good correlation between precipitable (sulphite) and functional (clotting rate) fibrinogen levels was observed in plasma collected on citrate before therapy (r = 0.76) and in samples collected after 3 hours on either aprotinin (r = 0.87) or PPACK (r = 0.82). Precipitable fibrinogen levels were approximately 10% higher than functional level, in baseline samples collected on citrate alone and approximately 20% higher in 3 hour samples collected on either PPACK or aprotinin. Fibrinogen levels measured with both assays correlated well, but were somewhat higher in samples collected on PPACK than on aprotinin. rt-PA antigen levels assayed in plasma collected in either inhibitor correlated well (r = 0.90) but were 10-20% higher in PPACK containing samples. Addition of heparin up to 9 units/ml to plasma had no effect on the functional fibrinogen assay.

Even with these precautions for assay artifact, a very poor correlation (r =-0.15) was observed between the plasma rt-PA level and the residual functional fibrinogen level, both after 3 hours and towards the end of the rt-PA infusion. A decrease of the fibrinogen level at the end of the infusion to below 1 g/l was observed in 36% of the patients and to below 0.5 g/l in 11%. Optimal monitoring of hemostasis during rt-PA infusion is achieved by fibrinogen assays with a clotting rate method on samples collected on either PPACK or aprotinin. Heparin at therapeutic levels does not interfere with this assay.

Shifting Boundaries in Professional Care

The nature of the work undertaken by different health professionals and inter-professional boundaries are constantly shifting. The greater knowledge of users of health care, and the increasing technical and organizational complexity of modern medicine, have partly eroded the control of health professionals over the substance of their work. The definition of a field of work as lying within the province of any one profession is culturally rather than scientifically determined.

It is evident that care of good quality should be delivered at the lowest possible cost. This might include delivery of care by a less trained person than heretofore, or by someone with limited but focused training. Sharing of skills is a more sensible subject for discussion than transfer of tasks. We review a number of studies which show the effectiveness of inter-professional substitution in various care settings, and also the effectiveness of substitution by those other than health professionals. The views of users of health services on inter-professional substitution need to be considered. Health professionals and others need to work together to devise innovative ways of delivering effective health care. The legal issues need clarification.

Allosteric Inhibitors against HIV-1 Reverse Transcriptase: Design and Synthesis of MKC-442 Analogues Having an Ω-Functionalized Acyclic Structure

Based on X-ray crystallographic analysis of MKC-442/human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) complex, analogues in which the N1-substituent is replaced with ω-functionalized alkyl groups were designed to improve the affinity for the enzyme. Synthesis of these compounds was carried out starting from MKC-442 by a sequence of reactions (N3-protection, removal of N1-ethoxymethyl group, alkylation, and N3-deprotection). The compounds were evaluated for anti-HIV activity. Structure–activity relationships are discussed in terms of the possible interaction with the enzyme.

Onchocerciasis control in the Democratic Republic of Congo (DRC): challenges in a post-war environment

OBJECTIVE

To evaluate onchocerciasis control activities in the Democratic Republic of Congo (DRC) in the first 12 years of community-directed treatment with ivermectin (CDTI).

METHODS

Data from the National Programme for Onchocerciasis (NPO) provided by the National Onchocerciasis Task Force (NOTF) through the annual reports of the 21 CDTI projects for the years 2001-2012 were reviewed retrospectively. A hypothetical-inputs-process-outputs-outcomes table was constructed.

RESULTS

Community-directed treatment with ivermectin expanded from 1968 communities in 2001 to 39 100 communities by 2012 while the number of community-directed distributors (CDD) and health workers (HW) multiplied. By 2012, there were ratios of 1 CDD per 262 persons and 1 HW per 2318 persons at risk. More than 80% of the funding came from the fiduciary funds of the African Programme for Onchocerciasis Control. The cost of treatment per person treated fell from US$ 1.1 in 2001 to US$ 0.1 in 2012. The therapeutic coverage increased from 2.7% (2001) to 74.2% (2012); the geographical coverage, from 4.7% (2001) to 93.9% (2012). Geographical coverage fell in 2005 due to deaths in loiasis co-endemic areas, and the therapeutic coverage fell in 2008 due to insecurity.

CONCLUSIONS

Challenges to CDTI in DRC have been serious adverse reactions to ivermectin in loiasis co-endemic areas and political conflict. Targets for personnel or therapeutic and geographical coverages were not met. Longer term funding and renewed efforts are required to achieve control and elimination of onchocerciasis in DRC.

Frameless stereotactic radiosurgery for the treatment of primary intracranial tumours in dogs

Stereotactic radiosurgery (SRS) is a procedure that delivers a single large radiation dose to a well-defined target. Here, we describe a frameless SRS technique suitable for intracranial targets in canines. Medical records of dogs diagnosed with a primary intracranial tumour by imaging or histopathology that underwent SRS were retrospectively reviewed. Frameless SRS was used successfully to treat tumours in 51 dogs with a variety of head sizes and shapes. Tumours diagnosed included 38 meningiomas, 4 pituitary tumours, 4 trigeminal nerve tumours, 3 gliomas, 1 histiocytic sarcoma and 1 choroid plexus tumour. Median survival time was 399 days for all tumours and for dogs with meningiomas; cause-specific survival was 493 days for both cohorts. Acute grade III central nervous system toxicity (altered mentation) occurred in two dogs. Frameless SRS resulted in survival times comparable to conventional radiation therapy, but with fewer acute adverse effects and only a single anaesthetic episode required for therapy.