Trends in outcomes of 862 giant hiatus hernia repairs over 30 years

PURPOSE

Laparoscopic giant hiatus hernia repair is technically difficult with ongoing debate regarding the most effective surgical technique. Repair of small hernia has been well described but data for giant hernia is variable. This study evaluated trends in outcomes of laparoscopic non-mesh repair of giant paraesophageal hernia (PEH) over 30 years.

METHODS

Retrospective analysis of a single-surgeon prospective database. Laparoscopic non-mesh repairs for giant PEH between 1991 and 2021 included. Three-hundred-sixty-degree fundoplication was performed routinely, evolving into "composite repair" (esophagopexy and cardiopexy to the right crus). Cases were chronologically divided into tertiles based on operation date (Group 1, 1991-2002; Group 2, 2003-2012; Group 3, 2012-2021) with trends in casemix, operative factors and outcomes evaluated. Hernia recurrence was plotted using weighted moving average and cumulative sum (CUSUM) analysis.

RESULTS

862 giant PEH repairs met selection criteria. There was an increasing proportion of "composite repair" after the first decade (Group 1, 2.7%; Group 2, 81.9%; Group 3, 100%; p < 0.001). There were less anatomical hernia recurrence (Group 1, 36.6%; Group 2, 22.9%; Group 3, 22.7%; p < 0.001) and symptomatic recurrence (Group 1, 34.2%; Group 2, 21.9%; Group 3, 7%; p < 0.001) over time. The incidence of anatomical recurrence declined over time, decreasing from 30.8% and plateauing below 17.6% near the study's end. Median followup (months) in the first decade was higher but followup between the latter two decades comparable (Group 1, 49 [IQR 20, 81]; Group 2, 30 [IQR 15, 65]; Group 3, 24 [14, 56]; p < 0.001). There were 10 (1.2%) Clavien-Dindo grade ≥ III complications including two perioperative deaths (0.2%).

CONCLUSION

Hernia recurrence rates decreased with increasing case volume. This coincided with the increasing adoption of "composite repair", supporting the possible improvement in recurrence rates with this approach.

Snacking practices from infancy to adolescence: parental perspectives from longitudinal lived experience research in England

Consumption of snacks and ultra-processed foods (UPF) high in fat, salt and sugar (HFSS) is associated with rising rates of obesity and growing socioeconomic disparities in nutrition. While infancy, childhood and adolescence are critical periods for development of dietary preferences, there remains a dearth of research exploring factors that underpin snacking behaviour over this time. This review aims to address this gap by drawing from qualitative lived experience research, with 122 families of different socioeconomic position (SEP), to explore how the (i) home food environment, (ii) food environment and (iii) social value and meanings of food shape parental provision of snacks. This review shows that snacking holds important meanings in everyday family life, with infants integrated into existing snacking practices from an early age. Price promotions, low-cost and long shelf-lives all make UPF and HFSS snacks an appealing option for many low-SEP parents; while children's requests and preferences for HFSS snacks present a challenge across SEP. However, higher-SEP parents can ensure fresh fruits are always available as an alternative snack, while fruit is described as a financially risky expenditure for low-SEP families. The present findings also indicate that retailers and producers are increasingly promoting 'healthier' snacks through product packaging and marketing, such as 'meets one of your five a day', despite these products displaying similar nutritional profiles to traditional UPF and HFSS snacks. We outline a series of policy recommendations, including extending Healthy Start Vouchers and the Fruit and Vegetable Scheme in schools and action to address misleading product marketing and packaging.

How can policies to reduce obesity be more effective and equitable following the COVID-19 pandemic?

 

Despite being a public health priority in the UK for decades, rates of childhood obesity are continuing to rise along a highly unequal socioeconomic gradient. COVID-19 has radically changed daily life, altering the economy, work, social lives and engagement with the food environment. This research aimed to investigate families’ lived experiences of food in the COVID-19 pandemic to understand how policies to reduce obesity can be more effective and equitable. We conducted a remote longitudinal qualitative study, engaging 62 parents of school or nursery age children in England. Participant demographics were diverse in terms of socioeconomic status and ethnicity. Participants took part in semi-structured interviews and photo-elicitation three times at six-month intervals between October 2020 and December 2021. The role of food in day-to-day life shifted in the context of changes brought about by the pandemic. Whether this led to healthy or unhealthy food practices was shaped by socioeconomic resources. Food became a key source of pleasure in daily life as social and leisure activities were restricted in lockdowns. As schools and childcare closed, when this work fell on one parent food became a source of relentless work and parents sought more convenient options. Those with financial resources were able to access healthier convenient options (e.g. meal boxes), while low incomes restricted parents to low-cost options (e.g. ready meals and fast food). For those experiencing financial insecurity, food became a financial management strategy and parents sought discounts and promotions to save money to cover other non-food essentials. These contexts have the capacity to occur again both on a large scale (e.g. disruptions to the food system) and in the context of an individual’s lifetime (e.g. ill health or job loss). Policy now has a window of opportunity to implement learnings from this period and shape obesity prevention policy to be more effective and equitable.

Key messages

• COVID-19 has revealed the multiple resources and systems of support that underpin families’ ability to eat well and, when disrupted, can limit capacity to procure and prepare nutritious foods.

• Policies designed to improve diets must consider the multiple roles food plays in everyday life, beyond just a source of nutrition, to ensure actions are effective and equitable.

POS0950 LONG-TERM FOLLOW-UP OF STARTING AND SWITCHING FROM ORIGINAL ADALIMUMAB TO ADALIMUMAB BIOSIMILAR: REAL-WORLD DATA IN AXIAL SPONDYLOARTHRITIS

Background

Biological drugs have revolutionized the treatment of rheumatic diseases, and the recent expiry of the patents for many biological agents has led to the marketing of highly similar, low-cost versions known as biosimilars. However, questions regarding its efficacy compared to bio-originator drugs, in a real-life setting, have been raised. National Institute for Health and Care Excellence (NICE) guidelines state that the response to biologic disease-modifying anti-rheumatic drugs (bDMARDs) should be assessed 12 weeks after the beginning of the drug. Treatment should only be continued if there is clear evidence of response, defined as a reduction in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score to 50% of the pre-treatment value or by 2 or more units and a reduction in the 10-cm spinal pain visual analogue scale (VAS) by 2 cm or more.

Objectives

To compare the response to adalimumab (ADA) originator and biosimilar in bDMARD-naïve patients with axial spondyloarthritis (axSpA) and in patients who switched from originator to biosimilar drug, accordingly to NICE guidelines; to compare the effectiveness and safety of the originator and biosimilar drugs in patients with axSpA, measured by persistence rates (PR) over three years.

Methods

A retrospective observational single-centre UK study was performed in bDMARD-naïve patients with a clinical diagnosis of axSpA who initiated treatment with ADA (original or biosimilar) and in patients who switched from originator to biosimilar drug. Descriptive statistics were used. Disease activity at baseline and follow-up data at 3 and 6 months of treatment was compared using the chi-square test. The Kaplan-Meier method was used to calculate persistence rates in biologic treatment over time. Reasons for discontinuing therapy were summarized using descriptive statistics and stratified by treatment.

Results

A total of 153 patients were included: 83 patients started on original ADA, 31 started on biosimilar ADA and 40 switched from original to biosimilar drug. The population’s baseline characteristics are similar in the three groups. However, some differences were found, namely disease duration was longer in the group that did switch and the disease activity is similar in patients who started original and biosimilar ADA and was lower in the group of patients who switched from original to the biosimilar. The 3-year PR was not significantly different between originator and biosimilar ADA in bDMARD naïve patients and in the group of patients that switched from original drug to biosimilar drug (p=0.080), as shown in Figure 1. In the original ADA group, 3-years PR was 67.5% with a median time-on-drug (TOD) of 29.5 months; for biosimilar drug, 3-years PR was 64.5%, with a median TOD of 24.2 months. In patients who switched from original to biosimilar drug, 3-years PR was 77.5% with a median TOD of 30.3 months. Response to treatment according to NICE guidelines was similar between original and biosimilar drugs (p>0.05). Overall, 47 (30.7%) patients stopped adalimumab (27 patients on original drug and 20 on biosimilar drug). Discontinuations due to adverse events and inefficacy were the most frequent, and there were no significant differences between original and biosimilar drugs. Other reasons for discontinuation were less frequent, such as patient choice, loss of follow-up and death, and again without differences between original and biosimilar drugs.

Figure 1.

Drug survival in the three adalimumab groups (original adalimumab – blue line, biosimilar adalimumab – red line, and switch from original to biosimilar adalimumab – green line)

Conclusion

Adalimumab original and biosimilar used as a first-line biological treatment showed similar effectiveness and safety in our long-term cohort of patients with axSpA. Switch from original to biosimilar drug showed to have a good persistence on drug after three years of follow-up (77.5%).

Disclosure of Interests

Ana Sofia Pinto: None declared, Kalveer Flora: None declared, Dilpreet Matharu: None declared, Anthony Isaacs: None declared, Pedro Machado Speakers bureau: Received consulting/speaker’s fees from Abbvie, BMS, Celgene, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB, all unrelated to this manuscript, Consultant of: Received consulting/speaker’s fees from Abbvie, BMS, Celgene, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB, all unrelated to this manuscript

Replicated gene expression changes in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Horizon 2020 CATCH ME; Cardiovascular Research Netherlands RACE V

Background

Little is known about changes in the atrial transcriptome associated with paroxysmal and persistent atrial fibrillation (AF).

Purpose

To identify major molecular mechanisms in AF, we determined consistent differential expression (DE) between atrial tissue samples from well-characterized patients with paroxysmal or persistent AF and patients without a history of AF (no AF) in two independent patient cohorts.

Methods

Poly-A tailed RNA from left and right atrial appendage tissue samples from independent discovery and replication cohorts CATCH ME (n=192) and RACE V (n=122) was sequenced and analyzed according to patient AF history. Analyses were performed stratified by atrial side, adjusting for age, sex, heart failure and a combination of clinical characteristics determined by principal component analysis. Transcripts were considered DE in CATCH ME if their fold change reached transcriptome-wide significance (false discovery rate (FDR) &lt; 0.05). DE transcripts in each rhythm comparison were replicated in RACE V if we observed a concordant direction of effect and a within-set FDR &lt; 0.05 in the same comparison.

Results

Persistent AF compared to no AF was associated with 184 left atrial DE transcripts in CATCH ME of which 85 (46%) were replicated in RACE V, and with 208 right atrial DE transcripts in CATCH ME of which 86 (41%) were replicated in RACE V. Overall, 26 transcripts were discovered and replicated in both atria. Discovered but non-replicated transcripts often did exhibit concordant direction of effect (left: 78%, right: 83%). Replicated transcripts consisted of protein coding genes, antisense and non-coding RNAs. Protein coding genes showed involvement in pathways linking persistent AF to cardiomyocyte structure, conduction properties, fibrosis, inflammation, molecule trafficking, and endothelial dysfunction. Interestingly, paroxysmal AF was not consistently associated with DE transcripts in any comparison. Principal component analysis of the expression of the 26 transcripts strongly associated with persistent AF did however reveal a distinct paroxysmal AF expression profile in-between no AF and persistent AF patients in the first principal component scores (Figure 1).

Conclusion

RNA sequencing of human atrial tissue samples identified many transcripts associated with persistent AF in left and/or right atria, discovered and replicated using two independent cohorts. These consistent findings of AF-induced changes provide a starting point for targeted proteomic analysis and single-nucleus sequencing to further unravel the molecular mechanisms underlying AF progression to persistent AF, and biomarker development to quantify AF progression and enable precision medicine in individual patients.

Atrial endomysial fibrosis is associated with sex, atrial fibrillation, heart failure and age in cardiac surgery patients: results from the Catch-Me consortium

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020

Background

Risk factors for atrial fibrillation (AF), such as ageing, heart failure and AF itself, enhance AF propensity partly by inducing atrial fibrosis. Atrial endomysial fibrosis, a type of reactive fibrosis occurring between cardiomyocytes, impairs transverse conduction in rapid atrial pacing animal models. The factors underlying transcriptional regulation of endomysial fibrosis are largely unknown.

Objective

To examine the contributions of age, sex, AF and heart failure to the development of endomysial fibrosis in the context of concurrent pathologies. To study genome-wide transcriptional changes associated with endomysial fibrosis in human left and right atrial appendage biopsies (LAA, n=95; RAA, n=76).

Methods

An algorithm for automated quantification of endomysial fibrosis following staining with wheat germ agglutinin (WGA) was employed. Linear mixed models were constructed to determine endomysial fibrosis quantity as a function of AF, heart failure, sex, age and four principal components that accounted for potential confounding effects of other clinical characteristics. RNA sequencing was used to study expression changes in the atrial transcriptome associated with endomysial fibrosis.

Results

Sex, persistent AF, heart failure and age were independently associated with endomysial fibrosis. We identified hundreds (LAA: 386, RAA: 311) of RNA transcripts associated with endomysial fibrosis. None of these associations were independent from the clinical phenotypes. However, explorative gene set enrichment analysis identified association of endomysial fibrosis with gene sets involved in extracellular matrix organization, immune response, cell motility, developmental processes, cardiac muscle contraction and proteostasis in LAA while in RAA only gene sets regulating contractile function were enriched.

Conclusion

Besides AF, female sex, age and heart failure are associated with endomysial fibrosis in the atria. While abundance of none of the differential genes were independently associated with endomysial fibrosis, gene set enrichment analysis suggests an involvement of extracellular matrix organization, immune response, cell motility, developmental processes and cardiac muscle contraction in endomysial fibrosis.

RNA-seq profiling of the atrial transcriptome reveals gender-specific patterns and interactions with atrial fibrillation and heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): TRAIN-HEART Innovative Training Network, funded by the European Union’s Horizon 2020 research and innovation program (under the Marie Sklodowska-Curie grant agreement no. 813716) Characterizing Atrial fibrillation by Translating its Causes into Health Modifiers in the Elderly (CATCH ME), funded by the European Union’s Horizon 2020 research and innovation program (under the grant agreement no. 633196)

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with heart failure (HF) and stroke. Clinical and experimental data from previous studies suggest gender differences in mechanisms and phenotypes of AF: women may have more atrial fibrosis, worse outcomes after catheter ablation, and some women carry a higher risk for thromboembolic complications than men. The molecular mechanisms underlying these differences are still poorly understood.

Methods

Gender-based transcriptional patterns were assessed using paired-end, directional RNA sequencing data generated from atrial tissue biopsies in 199 patients either in sinus rhythm or with paroxysmal or persistent AF as part of the CATCH-ME project. Transcript counts were compared between genders separately in the left and right atria using the DESeq2 package in R. The models were adjusted for potential sources of confounding (age, atrial fibrillation status, heart failure status and sequencing batch). Interaction models were implemented using DESeq2 to compare gender*morbidity interactions for persistent AF and HF. Significance was assessed using likelihood ratio tests comparing models with and without the interaction terms. Results with an adjusted P-value  0.05 were considered significant and utilized for subsequent downstream assessments. Differentially expressed (DE) genes were tested for enrichment of gene ontology (GO) terms and KEGG pathways using the WebGestalt toolkit.

Results

Transcriptome-wide profiling across the cohort identified 33 sex-differentiated genes in the left atria and 51 in the right atrial samples, with 21 of these showing bilateral differences. Interestingly, 36 (44%) of the results from these analyses were comprised of non-coding transcripts, including long non-coding RNAs (lncRNAs), antisense RNAs and pseudogenes. GO and pathway enrichment analyses for these genes revealed their involvement in critical pathways such as the complement and coagulation cascades and RNA transport.  Interaction analyses between gender and AF identified two genes (MPP2 & GNAS-AS1) that were differentially transcribed in the right atria and one gene (MYL2) that was DE in the left atria by gender in persistent AF samples. A similar analysis comparing gender*HF morbidity also revealed evidence of DE. Four transcripts (HLA-DQB1-AS1, EIF1AY, UTY and ZFY-AS1) showed gender-specific differences in expression by HF status in left atria, while HLA-DQB1-AS1 was differentially regulated by gender and HF status in right atrial samples.

Conclusions

These RNA-seq analyses provide novel insights into gender-related differences in the transcriptional landscape of right and left adult human atrial appendages. Moreover, interaction analyses identified three genes DE in female atria in persistent AF and four DE genes in female atria in heart failure, providing a molecular anchor for the observed differences in atrial diseases phenotypes between men and women.

Reappraisal of Atrial fibrillation: interaction between hyperCoagulability, Electrical remodelling and Vascular destabilisation in the progression of AF (RACE V) Tissue Bank Project: study design

Background

The development of atrial fibrillation (AF) is a complex multifactorial process. Over the past few decades, much has been learned about the pathophysiological processes that can lead to AF from a variety of specific disease models in animals. However, our ability to recognise these disease processes in AF patients is still limited, which has contributed to the limited progress in improving rhythm control in AF.

Aims/objectives

We believe that a better understanding and detection of the individual pathophysiological mechanisms underlying AF is a prerequisite for developing patient-tailored therapies. The RACE V Tissue Bank Project will contribute to the unravelling of the main molecular mechanisms of AF by studying histology and genome-wide RNA expression profiles and combining this information with detailed phenotyping of patients undergoing cardiac surgery.

Methods

As more and more evidence suggests that AF may occur not only during the first days but also during the months and years after surgery, we will systematically study the incidence of AF during the first years after cardiac surgery in patients with or without a history of AF. Both the overall AF burden as well as the pattern of AF episodes will be studied. Lastly, we will study the association between the major molecular mechanisms and the clinical presentation of the patients, including the incidence and pattern of AF during the follow-up period.

Conclusion

The RACE V Tissue Bank Project combines deep phenotyping of patients undergoing cardiac surgery, including rhythm follow-up, analysis of molecular mechanisms, histological analysis and genome-wide RNA sequencing. This approach will provide detailed insights into the main pathological alterations associated with AF in atrial tissue and thereby contribute to the development of individualised, mechanistically informed patient-tailored treatment for AF.

Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.

Somatic, positive and negative domains of the Center for Epidemiological Studies Depression (CES-D) scale: a meta-analysis of genome-wide association studies

BACKGROUND

Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains.

METHOD

We performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons).

RESULTS

One single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (p discovery = 3.82 × 10-8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (p discovery+replication = 1.10 × 10-6) with evidence of heterogeneity.

CONCLUSIONS

Despite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.

CLEC4M and STXBP5 gene variations contribute to von Willebrand factor level variation in von Willebrand disease

BACKGROUND

von Willebrand factor (VWF) levels in healthy individuals are influenced by variations in genetic loci other than the VWF gene, whose contribution to VWF levels in patients with von Willebrand disease (VWD) is largely unknown.

OBJECTIVES

To investigate the association between single-nucleotide polymorphisms (SNPs), VWF levels, and bleeding phenotype.

PATIENTS/METHODS

In 364 type 1 VWD and 240 type 2 VWD patients from the nationwide cross-sectional 'Willebrand in The Netherlands' (WiN) study, we studied the association between eight SNPs in STXBP5, SCARA5, ABO, VWF, STAB2, STX2, TC2N, and CLEC4M, and VWF antigen (VWF:Ag), VWF activity (VWF:Act), and bleeding phenotype as assessed with the Tosetto bleeding score.

RESULTS

In type 1 patients, STXBP5 was associated with a lower VWF:Ag level (adjusted difference of -3.0 IU dL(-1) per allele; 95% confidence interval [CI] -6.0 to 0.1) and CLEC4M with both a lower VWF:Ag level (-4.3 IU dL(-1) per allele; 95% CI -7.9 to -0.6) and lower VWF:Act (-5.7 IU dL(-1) per allele; 95% CI -10.9 to -0.5). In type 2 patients, none of the SNPs was associated with VWF levels. None of the genetic variants was associated with bleeding score.

CONCLUSIONS

Genetic variations in STXBP5 and CLEC4M are associated with VWF level variation in type 1 VWD, but not in type 2 VWD. This study increases our understanding of the pathophysiology of VWD, and provides a further indication of the involvement of STXBP5 and CLEC4M in determining VWF levels in VWD.

Quality of care and cost of prescriptions for diabetes and hypertension at primary healthcare facilities in the Cape Town Metropole

Background: Quality of care for diabetes mellitus and hypertension has been found to be suboptimal at primary health care level. There is an expectation that improving quality will require the increased utilisation of resources. This research was intended to determine the quality of care and cost of prescriptions at 10 facilities in the Cape Town Metropole.Method: An analytical, cross-sectional study was conducted in order to relate the cost of medication to quality-of-care indicators for patients with diabetes mellitus and hypertension. Data were collected at the 10 facilities in the Cape Town Metropole over a three-month period.Results: Quality-of-care processes were performed more often in diabetic than in hypertensive patients, i.e. determination of body mass index (BMI) 52.4% vs. 46.4%, creatinine 45.2% vs. 35.7% and cholesterol 44.5% vs. 35.4%, respectively. Nevertheless, outcome measures were better in the hypertensive patients. Targets were achieved in hypertensive vs. diabetic patients, respectively, as follows: BMI (22.2% vs.18.1%), blood pressure (39.8% vs. 28.7%), creatinine (93.2% vs. 91.4%) and cholesterol (46.8% vs. 44%). The median cost per script was R44.66 and R30.06 for diabetic and hypertensive patients with good quality-of-care scores, respectively, and R51.18 and R31.00, for those with poor quality-of-care scores. Conclusion: The quality of care provided was poor when compared with the guideline recommendations, but was comparable to care provided in many other populations. There was no correlation between quality of care and the cost of the prescriptions.

Drug-gene interactions and the search for missing heritability: a cross-sectional pharmacogenomics study of the QT interval

Variability in response to drug use is common and heritable, suggesting that genome-wide pharmacogenomics studies may help explain the 'missing heritability' of complex traits. Here, we describe four independent analyses in 33 781 participants of European ancestry from 10 cohorts that were designed to identify genetic variants modifying the effects of drugs on QT interval duration (QT). Each analysis cross-sectionally examined four therapeutic classes: thiazide diuretics (prevalence of use=13.0%), tri/tetracyclic antidepressants (2.6%), sulfonylurea hypoglycemic agents (2.9%) and QT-prolonging drugs as classified by the University of Arizona Center for Education and Research on Therapeutics (4.4%). Drug-gene interactions were estimated using covariable-adjusted linear regression and results were combined with fixed-effects meta-analysis. Although drug-single-nucleotide polymorphism (SNP) interactions were biologically plausible and variables were well-measured, findings from the four cross-sectional meta-analyses were null (Pinteraction>5.0 × 10(-8)). Simulations suggested that additional efforts, including longitudinal modeling to increase statistical power, are likely needed to identify potentially important pharmacogenomic effects.

Plasma proprotein convertase subtilisin kexin type 9 levels are related to markers of cholesterol synthesis in familial combined hyperlipidemia

BACKGROUND AND AIMS

Two recent independent studies showed that patients with familial combined hyperlipidemia (FCHL) have elevated plasma levels of proprotein convertase subtilisin kexin type 9 (PCSK9) and markers of cholesterol synthesis. Both PCSK9 expression and cholesterol synthesis are downstream effects of hepatic activation of sterol regulatory element binding protein 2 (SREBP2). The present study was conducted to study the relationship between plasma PCSK9 and markers of cholesterol synthesis in FCHL.

METHODS AND RESULTS

Markers of cholesterol synthesis (squalene, desmosterol, lathosterol), cholesterol absorption (campesterol, sitosterol, cholestanol) and PCSK9 were measured in plasma of FCHL patients (n = 103) and their normolipidemic relatives (NLR; n = 240). Plasma PCSK9, lathosterol and desmosterol levels were higher in FCHL patients than their NLR (p < 0.001, age and sex adjusted). Heritability calculations demonstrated that 35% of the variance in PCSK9 levels could be explained by additive genetic effects (p < 0.001). Significant age- and sex-adjusted correlations were observed for the relationship between PCSK9 and lathosterol, both unadjusted and adjusted for cholesterol, in the overall FCHL population (both p < 0.001). Multivariate regression analyses, with PCSK9 as the dependent variable, showed that the regression coefficient for FCHL status decreased by 25% (from 0.8 to 0.6) when lathosterol was included. Nevertheless, FCHL status remained an independent contributor to plasma PCSK9 (p < 0.001).

CONCLUSIONS

The present study confirms the previously reported high and heritable PCSK9 levels in FCHL patients. Furthermore, we now show that high PCSK9 levels are, in part, explained by plasma lathosterol, suggesting that SREBP2 activation partly accounts for elevated PCSK9 levels in FCHL.

Genome-wide association analysis of coffee drinking suggests association with CYP1A1/CYP1A2 and NRCAM

Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N=18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values=1.6 × 10(-11) and 2.7 × 10(-11)), which were also in strong linkage disequilibrium (r(2)=0.7) with each other, lie in the 23-kb long commonly shared 5' flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value=3.9 × 10(-09)) near NRCAM-a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value=7.1 × 10(-09))-an SNP associated with blood pressure-in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value=2.2 × 10(-05)) and Parkinson's disease pathways (P-value=3.6 × 10(-05)).

A genome-wide linkage study of individuals with high scores on NEO personality traits

The NEO-Five-Factor Inventory divides human personality traits into five dimensions: neuroticism, extraversion, openness, conscientiousness and agreeableness. In this study, we sought to identify regions harboring genes with large effects on the five NEO personality traits by performing genome-wide linkage analysis of individuals scoring in the extremes of these traits (>90th percentile). Affected-only linkage analysis was performed using an Illumina 6K linkage array in a family-based study, the Erasmus Rucphen Family study. We subsequently determined whether distinct, segregating haplotypes found with linkage analysis were associated with the trait of interest in the population. Finally, a dense single-nucleotide polymorphism genotyping array (Illumina 318K) was used to search for copy number variations (CNVs) in the associated regions. In the families with extreme phenotype scores, we found significant evidence of linkage for conscientiousness to 20p13 (rs1434789, log of odds (LOD)=5.86) and suggestive evidence of linkage (LOD >2.8) for neuroticism to 19q, 21q and 22q, extraversion to 1p, 1q, 9p and12q, openness to 12q and 19q, and agreeableness to 2p, 6q, 17q and 21q. Further analysis determined haplotypes in 21q22 for neuroticism (P-values = 0.009, 0.007), in 17q24 for agreeableness (marginal P-value = 0.018) and in 20p13 for conscientiousness (marginal P-values = 0.058, 0.038) segregating in families with large contributions to the LOD scores. No evidence for CNVs in any of the associated regions was found. Our findings imply that there may be genes with relatively large effects involved in personality traits, which may be identified with next-generation sequencing techniques.

Genetic risk factors for cerebral small-vessel disease in hypertensive patients from a genetically isolated population

BACKGROUND

Asymptomatic cerebral lesions on MRI such as white matter lesions (WML), lacunes and microbleeds are commonly seen in older people. We examined the role of a series of candidate genes involved in blood pressure regulation and amyloid metabolism.

MATERIALS AND METHODS

The study was embedded in a family-based cohort sampled from a Dutch genetically isolated population. We selected individuals between 55 and 75 years of age with hypertension (N=129). Volumes of WML and presence of lacunes and microbleeds were assessed with MRI. We studied three genes involved in blood pressure regulation (angiotensin, angiotensin II type 1 receptor, α-adducin) and two genes involved in the amyloid pathway (apolipoprotein E (APOE) and sortilin-related receptor gene (SORL1)).

RESULTS

All participants had WML (median volume, 3.1 ml; interquartile range, 1.5-6.5 ml); lacunar infarcts were present in 15.5% and microbleeds in 23.3%. Homozygosity for the APOE ε4 allele was associated with lacunes (OR, 4.8; 95% CI, 1.2 to 19.3). Individuals carrying two copies of the variant allele of four single nucleotide polymorphism (SNPs) located at the 3'-end of SORL1 (rs1699102, rs3824968, rs2282649, rs1010159) had significantly more often microbleeds (highest OR, 6.87; 95% CI, 1.78 to 26.44).

CONCLUSION

The association of SORL1 with microbleeds suggests that the amyloid cascade is involved in the aetiology of microbleeds in populations with hypertension.

Cathepsin D gene and the risk of Alzheimer's disease: a population-based study and meta-analysis

Cathepsin D (CTSD) is a gene involved in amyloid precursor protein processing and is considered a candidate for Alzheimer's disease (AD). The aim of the current study was to examine if variation in CTSD increases the risk of AD. We performed a candidate-gene analysis in a population-based cohort study (N=7983), and estimated the effect of CTSD on the risk of AD. Additionally, a large meta-analysis was performed incorporating our data and previously published data. The T-allele of CTSD rs17571 was associated with an increased risk of AD (p-value 0.007) in the Rotterdam Study. This association was predominantly found in APOE ε4 noncarriers. A meta-analysis of previously published data showed a significantly increased risk of AD in carriers of the T-allele of rs17571 (OR 1.22, 95% CI 1.03-1.44), irrespective of APOE ε4 carrier status. This study adds to the evidence that CTSD increases the risk of AD, although the effect size is moderate.

Polymorphisms of the renin-angiotensin system are associated with blood pressure, atherosclerosis and cerebral white matter pathology

BACKGROUND

The renin-angiotensin system is involved in the development of hypertension, atherosclerosis and cardiovascular disease. We studied the association between the M235T polymorphism of the angiotensinogen gene (AGT) and the C573T polymorphism of the angiotensin II type 1 receptor (AT1R) and blood pressure, carotid atherosclerosis and cerebrovascular disease.

METHODS

We genotyped over 6000 subjects from the Rotterdam Study and more than 1000 subjects from the Rotterdam Scan Study. We used logistic regression and univariate analyses, adjusting for age and sex with, for AGT, the MM and, for AT1R, the TT genotype as reference.

RESULTS

We found that AGT-235T increased systolic (p for trend = 0.03) and diastolic blood pressure (p for trend = 0.04). The prevalence of carotid plaques was increased 1.25-fold (95% CI 1.02-1.52) in AGT-TT carriers. There was a significant increase in mean volume deep subcortical white matter lesions (WML) for AGT-TT carriers (1.78 ml vs 1.09 ml in the reference group; p = 0.008). A significant interaction was found between AGT and AT1R, further increasing the effect on periventricular and subtotal WML (p for interaction = 0.02). We found a non-significant increased risk of silent brain infarction for AGT-TT carriers and AT1R-CC carriers, but no effect on stroke.

CONCLUSION

We found an association between AGT and blood pressure, atherosclerosis and WML. Also, we found synergistic effects between AGT and AT1R on the development of WML. These findings raise the question of whether the renin-angiotensin system may be a therapeutic target for the prevention of cerebral white matter pathology.

ACEPolymorphisms

Angiotensin converting enzyme (ACE) plays an essential role in two physiological systems, one leading to the production of angiotensin II and the other to the degradation of bradykinin. The wide distribution and multifunctional properties of these peptides suggest that ACE could be involved in various pathophysiological conditions. The discovery that ACE levels are under genetic control ushered in a new era of investigation; most studies focused on an insertion/deletion (I/D) polymorphism in intron 16 of the ACE gene as a marker for a functional polymorphism. Recently, many single nucleotide polymorphisms were detected in the gene and the search for the locations of functional polymorphisms became a topic of extensive investigation. Nevertheless, association studies on the I/D polymorphism and clinical outcomes continued, mostly with conflicting results. This article reviews the current state of knowledge regarding ACE polymorphisms and suggests that a functional polymorphism is most likely located between intron 18 and the 3' UTR. The potential existence of another functional polymorphism in the 5' UTR, however, cannot be excluded. This review also presents an overview of ACE function in different pathophysiological systems, and summarizes previous reports on ACE and clinical outcomes. Although findings on the I/D polymorphism and disorders like diabetic nephropathy and Alzheimer disease can be considered conclusive, reports on most of the cardiovascular phenotypes are still controversial. Genotypic and phenotypic misclassifications, insufficient power in some studies, and the presence of interaction with other genes or environmental factors are possible explanations for the contradictory findings.

Familial aggregation, the PDE4D gene, and ischemic stroke in a genetically isolated population

OBJECTIVE

The purpose of this investigation was to study the familial aggregation of ischemic stroke and the association between the PDE4D gene and ischemic stroke.

METHODS

The study was performed in an isolated population in The Netherlands, where the authors identified 91 patients with ischemic stroke. Ischemic stroke was subclassified in large- and small-vessel infarction. The authors calculated kinship and inbreeding coefficients and genotyped all patients for three single-nucleotide polymorphisms (SNPs) in the PDE4D gene.

RESULTS

The proportion of related pairs was higher in patients with ischemic stroke (68.8%) compared with controls (30.7%; p < 0.001). For large-vessel infarction, the proportion of related pairs was higher (71%) compared with small-vessel infarction (62.8%; p < 0.001). Familial aggregation was strongest for patients with early onset (age at onset < 45 years). All stroke groups were significantly more inbred compared with controls. In inbred individuals, the C allele of SNP45 increased the risk of small-vessel infarction 4.8 times (95% CI 1.1 to 22.3) compared with controls (p = 0.04). The T allele of SNP39 increased the risk of small-vessel infarction 6.3 times (95% CI 1.4 to 28.7) compared with controls (p = 0.02). No associations were found for large-vessel stroke.

CONCLUSIONS

There was familial aggregation of ischemic stroke and a difference in degree of familial clustering between stroke subtypes. The authors also found that the PDE4D gene is significantly associated with small-vessel infarction in inbred individuals.

Problems with prostate specific antigen screening for prostate cancer in the primary healthcare setting in South Africa

OBJECTIVES

To assess the feasibility of detecting early-stage prostate cancer in the primary healthcare setting, and to investigate whether there is a higher incidence of prostate cancer in Black African men.

PATIENTS AND METHODS

The study was a collaboration with registrars in the authors' institutions and primary healthcare centres serving mainly a Black African or mixed ancestry (Coloured) population in the semi-urban Cape Town metropolitan area of South Africa. Men aged 50-70 years attending the clinics were counselled about prostate cancer and invited to have a digital rectal examination (DRE), serum prostate-specific antigen (PSA) assay and transrectal ultrasonography-guided sextant prostate biopsy if the DRE was clinically suspicious of malignancy or the serum PSA was > or = 4.0 ng/mL. An American Urological Association Symptom Index (AUA-SI) was obtained, and urine analysed using dipsticks.

RESULTS

From May 2000 to November 2001, 660 men were assessed (mean age 59.4 years, range 30-82); 60.6% were Black African, 37.3% mixed (Coloured), 1.8% White (Caucasian) and 0.2% Asian (Indian). The mean (range) AUA-SI was 5.98 (0-35) in the whole group; the DRE was recorded as clinically suspicious of malignancy in 3.2%. The mean PSA was 20.39 (0.04-10 000) ng/mL in the whole group, but when two outliers (1865 and 10 000 ng/mL) were disregarded, it was 2.4 ng/mL. In Black patients the mean PSA was 31.8 (0.04-10 000) ng/mL, and without the outliers, 2.1 ng/mL; in Coloured patients it was 2.94 (0.05-50) ng/mL. The PSA was > or = 4.0 ng/mL in 9.6% of the whole group, in 7.8% of Black and in 13% of Coloured patients. Prostate biopsies were taken in 21 patients (3.2% of the whole group and a third of those with a PSA of > or = 4.0 ng/mL); in Black patients, biopsies were taken in 1.5% and 19.4%, respectively, and in Coloured patients in 6.1% and 46.9%, respectively. The prostate biopsy showed cancer in 43% of the whole group, in a third of Black and in 47% of Coloured patients; prostate cancer was detected in 1.4%, 0.5% and 2.8%, respectively.

CONCLUSIONS

That prostate biopsies were obtained in only 19% of Black and in only 47% of Coloured men with a serum PSA of > or = 4.0 ng/mL is of concern. This indicates that there is a significant problem in getting men with an elevated serum PSA level to undergo a prostate biopsy in the primary healthcare setting in South Africa.

Validation

Validation is often considered to be a complex process that is arduous to implement. This article describes recommended validation techniques and answers frequently asked questions on how to validate machines and processes.

A systematic, genome-wide, phenotype-driven mutagenesis programme for gene function studies in the mouse

As the human genome project approaches completion, the challenge for mammalian geneticists is to develop approaches for the systematic determination of mammalian gene function. Mouse mutagenesis will be a key element of studies of gene function. Phenotype-driven approaches using the chemical mutagen ethylnitrosourea (ENU) represent a potentially efficient route for the generation of large numbers of mutant mice that can be screened for novel phenotypes. The advantage of this approach is that, in assessing gene function, no a priori assumptions are made about the genes involved in any pathway. Phenotype-driven mutagenesis is thus an effective method for the identification of novel genes and pathways. We have undertaken a genome-wide, phenotype-driven screen for dominant mutations in the mouse. We generated and screened over 26,000 mice, and recovered some 500 new mouse mutants. Our work, along with the programme reported in the accompanying paper, has led to a substantial increase in the mouse mutant resource and represents a first step towards systematic studies of gene function in mammalian genetics.

Apolipoprotein E epsilon4 allele has no effect on age at onset or duration of disease in cases of frontotemporal dementia with pick- or microvacuolar-type histology

Frontotemporal dementia (FTD) is the second most common cause of presenile dementia. Here we have investigated the frequency of the epsilon4 allele of the Apolipoprotein (APOE) gene in FTD and in other non-Alzheimer forms of dementia related to FTD such as Motor Neurone disease dementia, semantic dementia, progressive aphasia, progressive supranuclear palsy, and corticobasal degeneration. In none of these diagnostic groups did we find a significant increase in the APOE epsilon4 allelic frequency, compared to population values. Neither did we observe any affects of the epsilon4 allele upon age at onset or duration of disease. We conclude therefore that polymorphic variations in the APOE gene do not modulate either the occurrence or progression of these non-Alzheimer forms of dementia.

Construction of a detailed physical and transcript map of the FTDP-17 candidate region on chromosome 17q21

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is an autosomal dominant condition clinically characterized by behavioral, cognitive, and motor disturbances. Until now, at least 13 different FTDP-17 families that show linkage to chromosome 17q21 have been described. To characterize the FTDP-17 candidate region, flanked by the markers D17S1789 and D17S1804, we constructed a physical map in P1 and PAC clones. A detailed transcript map was generated by positioning known genes and EST clusters to the physical map. In total, we investigated 150 STSs mapped to this region. In addition, novel transcripts were isolated by exon-trapping. We were able to localize 19 known genes and a number of ESTs to this chromosomal region. Furthermore, seven novel genes were identified for which we isolated the full-length sequence.

Association of missense and 5'-splice-site mutations in tau with the inherited dementia FTDP-17

Thirteen families have been described with an autosomal dominantly inherited dementia named frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), historically termed Pick's disease. Most FTDP-17 cases show neuronal and/or glial inclusions that stain positively with antibodies raised against the microtubule-associated protein Tau, although the Tau pathology varies considerably in both its quantity (or severity) and characteristics. Previous studies have mapped the FTDP-17 locus to a 2-centimorgan region on chromosome 17q21.11; the tau gene also lies within this region. We have now sequenced tau in FTDP-17 families and identified three missense mutations (G272V, P301L and R406W) and three mutations in the 5' splice site of exon 10. The splice-site mutations all destabilize a potential stem-loop structure which is probably involved in regulating the alternative splicing of exon10. This causes more frequent usage of the 5' splice site and an increased proportion of tau transcripts that include exon 10. The increase in exon 10+ messenger RNA will increase the proportion of Tau containing four microtubule-binding repeats, which is consistent with the neuropathology described in several families with FTDP-17.

Localization of frontotemporal dementia with parkinsonism in an Australian kindred to chromosome 17q21-22

An Australian family with autosomal dominant presenile nonspecific dementia was recently described. The disease results in behavioral changes, usually disinhibition, followed by the onset of dementia accompanied occasionally by parkinsonism. Twenty-eight affected individuals were identified with an age of onset of 39 to 66 years (mean, 53 +/- 8.9 years). We mapped the disease locus to an approximately 26-cM region of chromosome 17q21-22 with a maximum two-point LOD score of 2.87. Affected individuals share a common haplotype between markers D17S783 and D17S808. This region of chromosome 17 contains the loci for several neurodegenerative diseases that lack distinctive pathological features, suggesting that these dementias, collectively referred to as frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), are caused by mutations in the same gene. The entire coding region of five genes, mapped to the FTDP-17 candidate region, were also sequenced. This analysis included the microtubule-associated protein tau that is the major component of the paired helical filaments observed in Alzheimer's disease. No pathogenic mutations were identified in either the tau gene or in any of the other genes analyzed.

On lumping and splitting: a fetus with clinical findings of the oral-facial-digital syndrome type VI, the hydrolethalus syndrome, and the Pallister-Hall syndrome

The three midline malformation complexes, the oral-facial-digital syndrome type VI (OFDS VI) or Váradi syndrome, the hydrolethalus syndrome (HS), and the Pallister-Hall syndrome (PHS) have been described as distinct genetic entities. Here, we report a fetus with a combination of clinical findings of all 3 syndromes similar to the twin fetuses described in the accompanying paper (Hingorani et al., 1991). The phenotypic overlap in these fetuses with the OFDS VI, HS, and PHS raises the question as to whether or not they indeed represent separate genetic entities as previously assumed.

Tuberculosis presenting as inflammatory bowel disease. Report of two cases

Two cases are reported of idiopathic inflammatory total colitis in patients with a previous history of tuberculosis. One showed colonoscopic and radiologic features of Crohn's disease and the other was diagnosed as ulcerative colitis. Tuberculous organisms were identified in the mesenteric nodes in one patient, but were not detected in the other. Both patients improved with antituberculous treatment. This report emphasizes the importance of considering tuberculosis in patients presenting with idiopathic inflammatory bowel disease of the colon and raises speculation of the possible infective etiology of Crohn's disease.

Feprazone compared with indomethacin in the management of rheumatoid arthritis

A double-blind cross-over trial of feprazone 450 mg daily and indomethacin 75 mg daily was carried out in fourteen patients with rheumatoid arthritis. The analgesic and anti-inflammatory activity was indistinguishable from that of indomethacin under the conditions of the trial. Seven patients expressed a preference for feprazone and four for indomethacin. Feprazone appeared to be well tolerated and free from serious side-effects. These results suggest that feprazone will be a useful drug in the management of rheumatoid arthritis.