Metabolomics and a Breath Sensor Identify Acetone as a Biomarker for Heart Failure.

BACKGROUND: Multi-omics delivers more biological insight than targeted investigations. We applied multi-omics to patients with heart failure with reduced ejection fraction (HFrEF). METHODS: 46 patients with HFrEF and 20 controls underwent metabolomic profiling, including liquid/gas chromatography mass spectrometry (LC-MS/GC-MS) and solid-phase microextraction (SPME) volatilomics in plasma and urine. HFrEF was defined using left ventricular global longitudinal strain, ejection fraction and NTproBNP. A consumer breath acetone (BrACE) sensor validated results in n = 73. RESULTS: 28 metabolites were identified by GCMS, 35 by LCMS and 4 volatiles by SPME in plasma and urine. Alanine, aspartate and glutamate, citric acid cycle, arginine biosynthesis, glyoxylate and dicarboxylate metabolism were altered in HFrEF. Plasma acetone correlated with NT-proBNP (r = 0.59, 95% CI 0.4 to 0.7), 2-oxovaleric and cis-aconitic acid, involved with ketone metabolism and mitochondrial energetics. BrACE > 1.5 ppm discriminated HF from other cardiac pathology (AUC 0.8, 95% CI 0.61 to 0.92, p < 0.0001). CONCLUSION: Breath acetone discriminated HFrEF from other cardiac pathology using a consumer sensor, but was not cardiac specific.

Multiomics, virtual reality and artificial intelligence in heart failure.

Aim: Multiomics delivers more biological insight than targeted investigations. We applied multiomics to patients with heart failure (HF) and reduced ejection fraction (HFrEF), with machine learning applied to advanced ECG (AECG) and echocardiography artificial intelligence (Echo AI). Patients & methods: In total, 46 patients with HFrEF and 20 controls underwent metabolomic profiling, including liquid/gas chromatography-mass spectrometry and solid-phase microextraction volatilomics in plasma and urine. HFrEF was defined using left ventricular (LV) global longitudinal strain, EF and N-terminal pro hormone BNP. AECG and Echo AI were performed over 5 min, with a subset of patients undergoing a virtual reality mental stress test. Results: A-ECG had similar diagnostic accuracy as N-terminal pro hormone BNP for HFrEF (area under the curve = 0.95, 95% CI: 0.85-0.99), and correlated with global longitudinal strain (r = -0.77, p < 0.0001), while Echo AI-generated measurements correlated well with manually measured LV end diastolic volume r = 0.77, LV end systolic volume r = 0.8, LVEF r = 0.71, indexed left atrium volume r = 0.71 and indexed LV mass r = 0.6, p < 0.005. AI-LVEF and other HFrEF biomarkers had a similar discrimination for HFrEF (area under the curve AI-LVEF = 0.88; 95% CI: -0.03 to 0.15; p = 0.19). Virtual reality mental stress test elicited arrhythmic biomarkers on AECG and indicated blunted autonomic responsiveness (alpha 2 of RR interval variability, p = 1 × 10-4) in HFrEF. Conclusion: Multiomics-related machine learning shows promise for the assessment of HF.

Lay abstract Multiomics is the integration of multiple sources of health information, for example, genomic, metabolite, etc. This delivers more insight than targeted single investigations and provides an ability to perceive subtle individual differences between people. In this study we applied multiomics to patients with heart failure (HF) using DNA sequencing, metabolomics and machine learning applied to ECG echocardiography. We demonstrated significant differences between subsets of patients with HF using these methods. We also showed that machine learning has significant diagnostic potential in identifying HF patients more efficiently than manual or conventional techniques.

Indirect regulation of CYP2C19 gene expression via DNA methylation.

1. Despite speculation that the CYP2C19 gene may contain CpG islands, there has been little direct assessment of the role for epigenetics in the regulation of this pharmacogene. The effect of 5-aza-2'-deoxycytidine (5azaDC), a DNA methyltransferase inhibitor, and trichostatin A (TSA), an inhibitor of histone deacetylases, on the expression of CYP2C19 and five of its known transcription factors (TF) has been assessed in cell lines derived from neoplastic liver and intestine. 2. CYP2C19 mRNA was substantially up-regulated (>18-fold) after treatment with 5azaDC despite the fact that the two intronic CpG islands in this gene remained substantially methylated (>50%). The TF NR1I3 was also consistently up-regulated after treatment with 5azaDC. NR1I3 lacks CpG islands in the proximal promoter region and is therefore not likely to be directly regulated by DNA methylation. Therefore, it appears that 5azaDC treatment affects an unidentified upstream regulator of both CYP2C19 and/or NR1I3. This is supported by the fact that the relationships between TF for CYP2C19 and the expression of this target gene in human liver samples only accounted for ∼70% of the variability of CYP2C19 mRNA levels. These data suggest that an yet un-identified 'master regulator' of CYP2C19 transcription could itself be a target of epigenetic control.

Lung cancer mutation testing: a clinical retesting study of agreement between a real-time PCR and a mass spectrometry test.

To investigate the clinical validity and utility of tests for detecting Epidermal Growth Factor Receptor (EGFR) gene mutations in non-squamous non-small cell lung cancer patients, tumour DNA extracts from 532 patients previously tested by the cobas EGFR Mutation Test (RT-PCR test) were retested by the Sequenom/Agena Biosciences MassArray OncoFocus mass spectrometry test (MS test). Valid results from both tests were available from 470 patients (88%) for agreement analysis. Survival data were obtained for 513 patients (96%) and 77 patients (14%) were treated with EGFR tyrosine kinase inhibitors (TKIs). Agreement analysis revealed moderately high positive (79.8%), negative (96.9%) and overall percentage agreement (93.2%) for the detection of EGFR mutations. However, EGFR mutations were detected by one test and not by the other test in 32 patients (7%). Retesting of discordant samples revealed false-positive and false-negative results generated by both tests. Despite this, treatment and survival outcomes correlated with the results of the RT-PCR and MS tests. In conclusion, this study provides evidence of the clinical validity and utility of the RT-PCR and MS tests for detection of EGFR mutations that predict prognosis and benefit from EGFR-TKI treatment. However, their false-positive and false-negative test results may have important clinical consequences.

EGFR Mutation Testing of non-squamous NSCLC: Impact and Uptake during Implementation of Testing Guidelines in a Population-Based Registry Cohort from Northern New Zealand.

BACKGROUND: Since 2013, clinical practice guidelines recommend EGFR mutation testing of non-squamous NSCLC to select advanced-stage patients for first-line treatment using EGFR-TKIs. OBJECTIVE: We aimed to determine population-based trends in the real-world uptake and impact in routine practice of these recently updated testing guidelines. PATIENTS AND METHODS: A population-based observational study was conducted of notifications to the New Zealand Cancer Registry of patients eligible for EGFR testing diagnosed in northern New Zealand between January 2010 and April 2014. The main study variable was EGFR mutation testing. Main outcome measures (overall survival and dispensing of EGFR-TKIs) were extracted from prospectively archived electronic databases until October 2015. RESULTS: The population-based cohort of 1857 patients had an average age of 70 years. Most had adenocarcinoma and metastatic disease at diagnosis. EGFR testing was undertaken in 500 patients (27%) with mutations detected in 109 patients (22%). EGFR testing increased during the period of study from <5% to 67% of patients (P < 0.0001). Full uptake of testing by all eligible patients was limited by a lack of availability of specimens for testing and variable testing referral practices. The proportion of patients treated with EGFR-TKIs decreased during the same time period, both among untested patients (from 12.2% to 2.8% (P < 0.0001)) and in the population as a whole (from 13.7% to 10.6% (P < 0.05)). EGFR testing was associated with prolonged overall survival (Adjusted HR = 0.76 (95% CI, 0.65-0.89) Log-rank P < 0.0001) due at least in part to the much longer overall survival achieved by mutation-positive patients, of whom 79% received EGFR-TKIs. Compared to untested EGFR-TKI-treated patients, mutation-positive EGFR-TKI-treated patients received EGFR-TKIs for longer, and survived longer both from the start of EGFR-TKI treatment and date of their diagnosis. CONCLUSIONS: In this real world setting, high uptake of EGFR testing was achieved and associated with major changes in EGFR-TKI prescribing and improved health outcomes. Modifiable factors determined testing uptake. Study registration ACTRN12615000998549.

Environmental factors and risk of aggressive prostate cancer among a population of New Zealand men - a genotypic approach.

Prostate cancer is one of the most significant health concerns for men worldwide. Numerous researchers carrying out molecular diagnostics have indicated that genetic interactions with biological and behavioral factors play an important role in the overall risk and prognosis of this disease. Single nucleotide polymorphisms (SNPs) are increasingly becoming strong biomarker candidates to identify susceptibility to prostate cancer. We carried out a gene × environment interaction analysis linked to aggressive and non-aggressive prostate cancer (PCa) with a number of SNPs. By using this method, we identified the susceptible alleles in a New Zealand population, and examined the interaction with environmental factors. We have identified a number of SNPs that have risk associations both with and without environmental interaction. The results indicate that certain SNPs are associated with disease vulnerability based on behavioral factors. The list of genes with SNPs identified as being associated with the risk of PCa in a New Zealand population is provided in the graphical abstract.

NRASQ61R Mutation-specific Immunohistochemistry is Highly Specific for Either NRASQ61R or KRASQ61R Mutation in Colorectal Carcinoma.

Anti-epidermal growth factor receptor-targeted therapy is only indicated in RAS wild-type colorectal carcinomas (CRCs). It is recommended that both NRAS and KRAS mutation testing to be performed before a CRC is considered RAS wild-type. Given that mutation-specific immunohistochemistry (IHC) has been shown to be sensitive and specific for the detection of NRAS mutations in melanoma, we assessed the specificity of NRAS mutation-specific IHC in CRC. IHC was performed on tissue microarrays containing 2823 consecutive CRC undergoing surgery with curative intent using a novel mutation-specific antibody to the protein produced by the NRAS mutation (clone SP174). Tissue microarrays were assessed by 2 observers and all IHC-positive or equivocal cases were repeated on whole sections to confirm the result. Positive cases then underwent molecular testing by matrix-assisted laser desorption/ionization-time of flight polymerase chain reaction. In total, 22 of 2823 (0.8%) CRCs demonstrated confirmed positive staining with complete interobserver concordance. RAS mutations were confirmed in all IHC-positive CRCs. In total, 11 cases harbored the NRASQ61R mutation. Surprisingly, 11 cases demonstrated the KRASQ61R mutation. We conclude that mutation-specific IHC with this currently available NRASQ61R antibody is highly specific for the presence of either NRASQ61R or KRASQ61R mutations in CRC. We caution that we did not assess the sensitivity of IHC and that this antibody does not detect other RAS mutations. Therefore, negative staining does not exclude a clinically significant RAS mutation. However, positive staining confirms the presence of an NRASQ61R or KRASQ61R mutation without the need for further molecular testing.

NRASQ61R Mutation-specific Immunohistochemistry Also Identifies the HRASQ61R Mutation in Medullary Thyroid Cancer and May Have a Role in Triaging Genetic Testing for MEN2.

A quarter of patients with medullary thyroid carcinoma (MTC) have germline mutations in the RET proto-oncogene indicating MEN2. Therefore genetic testing is recommended for all patients presenting with MTC. Approximately 40% of MTCs have somatic RET mutations. Somatic mutations in the RAS genes are the next most common driver mutations and appear to be mutually exclusive with germline RET mutation. The single most common somatic RAS mutation is HRASQ61R (c.182A>G), reported in 4.6% to 11% of all MTCs. Mutation-specific immunohistochemistry (IHC) initially developed to identify the NRASQ61R mutation in melanoma (clone SP174) has proven highly sensitive and specific. Because the amino acid sequences for the HRAS and NRAS proteins at codon 61 are identical, we postulated that SP174 IHC would also identify the somatic HRASQ61R mutation. IHC with SP174 was performed on a tissue microarray of 68 patients with MTC including 13 (22.8%) with molecularly confirmed MEN2. Seven (10.3%) MTCs demonstrated positive staining. Six of these patients had already undergone germline RET mutation testing as part of clinical care and were all confirmed to be wild type, excluding the diagnosis of MEN2. All SP174 immunohistochemically positive MTCs were proven to have HRASQ61R mutation (and lack KRASQ61R and NRASQ61R) by Sanger sequencing. All MEN2 patients showed negative staining. We conclude that IHC with SP174 is highly specific for the HRASQ61R mutation in MTC. Because current data suggest that this mutation is mutually exclusive with germline RET mutation, IHC may also have a role in triaging formal genetic testing for MEN2.

Cross-Comparison of Exome Analysis, Next-Generation Sequencing of Amplicons, and the iPLEX(®) ADME PGx Panel for Pharmacogenomic Profiling.

Whole-exome sequencing (WES) has been widely used for analysis of human genetic diseases, but its value for the pharmacogenomic profiling of individuals is not well studied. Initially, we performed an in-depth evaluation of the accuracy of WES variant calling in the pharmacogenes CYP2D6 and CYP2C19 by comparison with MiSeq(®) amplicon sequencing data (n = 36). This analysis revealed that the concordance rate between WES and MiSeq(®) was high, achieving 99.60% for variants that were called without exceeding the truth-sensitivity threshold (99%), defined during variant quality score recalibration (VQSR). Beyond this threshold, the proportion of discordant calls increased markedly. Subsequently, we expanded our findings beyond CYP2D6 and CYP2C19 to include more genes genotyped by the iPLEX(®) ADME PGx Panel in the subset of twelve samples. WES performed well, agreeing with the genotyping panel in approximately 99% of the selected pass-filter variant calls. Overall, our results have demonstrated WES to be a promising approach for pharmacogenomic profiling, with an estimated error rate of lower than 1%. Quality filters, particularly VQSR, are important for reducing the number of false variants. Future studies may benefit from examining the role of WES in the clinical setting for guiding drug therapy.

The natural history of elevated tetradecenoyl-L-carnitine detected by newborn screening in New Zealand: implications for very long chain acyl-CoA dehydrogenase deficiency screening and treatment.

Very long chain acyl-CoA dehydrogenase deficiency (VLCADD, OMIM #201475) has been increasingly diagnosed since the advent of expanded newborn screening (NBS). Elevated levels of tetradecenoyl-L-carnitine (C14:1) in newborn screening blood spot samples are particularly common in New Zealand, however this has not translated into increased VLCADD clinical presentations. A high proportion of screen-positive cases in NZ are of Maori or Pacific ethnicity and positive for the c.1226C > T (p.Thr409Met) ACADVL gene variant. We performed a retrospective, blinded, case-control study of 255 cases, born between 2006 and 2013, with elevated NBS C14:1 levels between 0.9 and 2.4 µmol/L, below the NZ C14:1 notification cut-off of 2.5 µmol/L. Coded healthcare records were audited for cases and age- and ethnicity- matched controls. The clinical records of those with possible VLCADD-related symptoms were reviewed. The follow-up period was 6 months to 7 years. Two of 247 cases (0.8 %) had possible VLCADD-like symptoms while four of 247 controls (2 %) had VLCADD-like symptoms (p = 0.81). Maori were overrepresented (68 % of the cohort vs 15 % of population). Targeted analysis of the c.1226 locus revealed the local increase in screening C14:1 levels is associated with the c.1226C > T variant (97/152 alleles tested), found predominantly in Maori and Pacific people. There was no increase in clinically significant childhood disease, irrespective of ethnicity. The study suggests that children with elevated C14:1, between 0.9-2.4 µmol/L, on NBS are at very low risk of clinically significant childhood disease. A minimally interventional approach to managing these patients is indicated, at least in the New Zealand population.

Distinguishing cytosine methylation using electrochemical, label-free detection of DNA hybridization and ds-targets.

In this communication we report on two important effects related to the detection of DNAs. Firstly, we investigate the sensor response to target DNA when the target is in a double stranded (ds) form and compare the response to single stranded (ss) target DNA. The importance in evaluating such an effect lies in the fact that most biological DNA targets are found in ds form. Secondly, we use synthetic ds targets to investigate the effect of DNA methylation on the sensor response. DNA methylation is known to affect functional properties of DNA and is related to a number of diseases, including various cancers. In these studies, we utilize our previously developed sensor platform, which is based on the use of a glassy carbon electrode-confined conducting polymer that is covalently modified with DNA probe sequences. The signal detection methodology we use is measuring a change in the reaction kinetics of ferro-ferricyanide redox couple at the electrode upon hybridization by means of electrical impedance spectroscopy (EIS). Additionally, EIS is utilized to study the kinetics of the hybridization of the conducting polymer-bound probe with methylated vs. non-methylated ds-DNA. Preliminary results are proving valuable as a guide to the future design of sensors for gene methylation.

Personalized hypertension management in practice.

The revolution occurring in genomic and personalized medicine is likely to have a significant impact on the management of hypertension. However, from the perspective of translating new knowledge into clinical practice, progress has been slow. This review article summarizes recent advances in hypertension-related diagnostics while also offering new perspective on hypertension management for the future. Such new perspectives will likely require a paradigm shift toward more integrated and holistic approaches for better prevention and treatment of hypertension in both individuals and the population as a whole.

High risk of human papillomavirus type 16 infections and of development of cervical squamous intraepithelial lesions in systemic lupus erythematosus patients.

OBJECTIVE: To determine rates of human papillomavirus (HPV) infections, abnormal cervical smears, and squamous intraepithelial lesions (SIL) among women with systemic lupus erythematosus (SLE). METHODS: We investigated 30 women with SLE, 67 with abnormal smears from colposcopy clinics, and 15 community subjects with normal smears. Polymerase chain reaction results for viral DNA and HPV-16 sequencing data were correlated to cytology and colposcopic findings. RESULTS: SLE and colposcopy patients were more likely (P < 0.05) to be HPV positive (15 [54%] and 37 [67%] patients, respectively) and HPV-16 DNA positive (16 [57%] and 17 [31%] patients, respectively) than community subjects (0% HPV DNA positive and 1 [6%] HPV-16 DNA positive). SLE patients were also more likely to be HPV-16 DNA positive than colposcopy patients (P < 0.05). SLE patients with a high HPV-16 viral load more frequently had SIL (n = 6) than those with a low HPV-16 viral load (n = 1; P < 0.05). HPV and HPV-16 DNA positivity were not associated with previous or current drug therapy for SLE patients. All HPV-16 DNA sequences from 6 SLE and 5 colposcopy patients were the European-type variant. Eighteen (60%) SLE patients had a previous or current cervical abnormality. At the time of study, 5 (17%) SLE patients had an abnormal cervical smear and 8 (27%) had SIL. For those diagnosed with SLE for >10 years, the rate of SIL was 44% lower than those with SLE for <5 years (odds ratio 0.56, 95% confidence interval 0.1-3.5). CONCLUSION: UK women with a recent SLE diagnosis had disturbingly elevated levels of HPV infections (particularly with European HPV-16 variants at a high viral load), abnormal cervical cytology, and SIL.