The use of pledget-reinforced sutures during surgical aortic valve replacement: A systematic review and meta-analysis.

Objective: Literature presents conflicting results on the pros and cons of pledget-reinforced sutures during surgical aortic valve replacement (SAVR). We aimed to investigate the effect of pledget-reinforced sutures versus sutures without pledgets during SAVR on different outcomes in a systematic review and meta-analysis. Methods: A literature search was performed in five different medical literature databases. Studies must include patients undergoing SAVR and must compare any pledget-reinforced with any suturing technique without pledgets. The primary outcome was paravalvular leakage (PVL), and secondary outcomes comprised thromboembolism, endocarditis, mortality, mean pressure gradient (MPG) and effective orifice area (EOA). Results were pooled using a random-effects model as risk ratios (RRs) or mean differences (MDs) for which the no pledgets group served as reference. Results: Nine observational studies met the inclusion criteria. The risk of bias was critical in seven studies, and high and moderate in two other. The pooled RR for moderate or greater PVL was 0.59 (95 % confidence interval [CI] 0.13, 2.73). The pooled RR for mortality at 30-days was 1.02 (95 % CI 0.48, 2.18) and during follow-up was 1.15 (95 % CI 0.67, 2.00). For MPG and EOA at 1-year follow-up, the pooled MDs were 0.60 mmHg (95 % CI -4.92, 6.11) and -0.03 cm2 (95 % CI -0.18, 0.12), respectively. Conclusions: Literature on the use of pledget-reinforced sutures during SAVR is at high risk of bias. Pooled results are inconclusive regarding superiority of either pledget-reinforced sutures or sutures without pledgets. Hence, there is no evidence to support or oppose the use of pledget-reinforced sutures.

Current definitions of hemodynamic structural valve deterioration after bioprosthetic aortic valve replacement lack consistency.

Objective: New echocardiographic definitions have been proposed for hemodynamic structural valve deterioration. We aimed to study their consistency in classifying structural valve deterioration after surgical aortic valve replacement. Methods: Data were used of patients undergoing surgical aortic valve replacement in a multicenter, prospective cohort study with a 5-year follow-up. All patients received the same stented bioprosthesis. Echocardiographic parameters were assessed by an independent core laboratory. Moderate or greater stenotic hemodynamic structural valve deterioration was defined according to Capodanno and colleagues, Dvir and colleagues, and the Valve Academic Research Consortium 3; regurgitation data were not considered in this analysis. Consistency was quantified on the basis of structural valve deterioration classification at subsequent time points. Results: A total of 1118 patients received implants. Patients' mean age was 70 years, and 75% were male. Hemodynamic structural valve deterioration at any visit was present in 51 patients (4.6%), 32 patients (2.9%), and 34 patients (3.0%) according to Capodanno, Dvir, and Valve Academic Research Consortium 3. A total of 1064 patients (95%) were never labeled with structural valve deterioration by any definition. After the first classification with structural valve deterioration, 59%, 59%, and 65% had no subsequent structural valve deterioration classification according to Capodanno, Dvir, and Valve Academic Research Consortium 3, respectively. Conclusions: The current definitions of hemodynamic structural valve deterioration are strong negative predictors but inconsistent positive discriminators for the detection of stenotic hemodynamic structural valve deterioration. Although the diagnosis of structural valve deterioration may be categorical, echocardiographic indices lack this degree of precision in the first 5 years after surgical aortic valve replacement. The inconsistency of current structural valve deterioration definitions impedes the detection of true valve degeneration, which challenges the clinical usefulness of these definitions.

Do postoperative hemodynamic parameters add prognostic value for mortality after surgical aortic valve replacement?

Background: Although various hemodynamic parameters to assess prosthetic performance are available, prosthesis-patient mismatch (PPM) is defined exclusively by effective orifice area (EOA) index thresholds. Adjusting for the Society of Thoracic Surgeons predicted risk of mortality (STS PROM), we aimed to explore the added value of postoperative hemodynamic parameters for the prediction of all-cause mortality at 5 years after aortic valve replacement. Methods: Data were obtained from the Pericardial Surgical Aortic Valve Replacement (PERIGON) Pivotal Trial, a multicenter prospective cohort study examining the performance of the Avalus bioprosthesis. Candidate predictors were assessed at the first follow-up visit; patients who had no echocardiography data, withdrew consent, or died before this visit were excluded. Candidate predictors included peak jet velocity, mean pressure gradient, EOA, predicted and measured EOA index, Doppler velocity index, indexed internal prosthesis orifice area, and categories for PPM. The performance of Cox models was investigated using the c-statistic and net reclassification improvement (NRI), among other tools. Results: A total of 1118 patients received the study valve, of whom 1022 were eligible for the present analysis. In univariable analysis, STS PROM was the sole significant predictor of all-cause mortality (hazard ratio, 1.40; 95% confidence interval, 1.26-1.55). When extending the STS PROM with single hemodynamic parameters, neither the c-statistics nor the NRIs demonstrated added prognostic value compared to a model with STS PROM alone. Similar findings were observed when multiple hemodynamic parameters were added. Conclusions: The STS PROM was found to be the main predictor of patient prognosis. The additional prognostic value of postoperative hemodynamic parameters for the prediction of all-cause mortality was limited.

Confounding adjustment in observational studies on cardiothoracic interventions: a systematic review of methodological practice.

OBJECTIVES: It is unknown which confounding adjustment methods are currently used in the field of cardiothoracic surgery and whether these are appropriately applied. The aim of this study was to systematically evaluate the quality of conduct and reporting of confounding adjustment methods in observational studies on cardiothoracic interventions. METHODS: A systematic review was performed, which included all observational studies that compared different interventions and were published between 1 January and 1 July 2022, in 3 European and American cardiothoracic surgery journals. Detailed information on confounding adjustment methods was extracted and subsequently described. RESULTS: Ninety-two articles were included in the analysis. Outcome regression (n = 49, 53%) and propensity score (PS) matching (n = 44, 48%) were most popular (sometimes used in combination), whereas 11 (12%) studies applied no method at all. The way of selecting confounders was not reported in 42 (46%) of the studies, solely based on previous literature or clinical knowledge in 14 (16%), and (partly) data-driven in 25 (27%). For the studies that applied PS matching, the matched cohorts comprised on average 46% of the entire study population (range 9-82%). CONCLUSIONS: Current reporting of confounding adjustment methods is insufficient in a large part of observational studies on cardiothoracic interventions, which makes quality judgement difficult. Appropriate application of confounding adjustment methods is crucial for causal inference on optimal treatment strategies for clinical practice. Reporting on these methods is an important aspect of this, which can be improved.

Improving accuracy in diagnosing aortic stenosis severity: An in-depth analysis of echocardiographic measurement error through literature review and simulation study.

AIMS: The present guidelines advise replacing the aortic valve for individuals with severe aortic stenosis (AS) based on various echocardiographic parameters. Accurate measurements are essential to avoid misclassification and unnecessary interventions. The objective of this study was to evaluate the influence of measurement error on the echocardiographic evaluation of the severity of AS. METHODS AND RESULTS: A systematic review was performed to examine whether measurement errors are reported in studies focusing on the prognostic value of peak aortic jet velocity (Vmax ), mean pressure gradient (MPG), and effective orifice area (EOA) in asymptomatic patients with AS. Out of the 37 studies reviewed, 17 (46%) acknowledged the existence of measurement errors, but none of them utilized methods to address them. Secondly, the magnitude of potential errors was collected from available literature for use in clinical simulations. Interobserver variability ranged between 0.9% and 8.3% for Vmax and MPG but was higher for EOA (range 7.7%-12.7%), indicating lower reliability. Assuming a circular left ventricular outflow tract area led to a median underestimation of EOA by 23% compared to planimetry by other modalities. A clinical simulation resulted in the reclassification of 42% of patients, shifting them from a diagnosis of severe AS to moderate AS. CONCLUSIONS: Measurement errors are underreported in studies on echocardiographic assessment of AS severity. These errors can lead to misclassification and misdiagnosis. Clinicians and scientists should be aware of the implications for accurate clinical decision-making and assuring research validity.

Early and late effects of aortic root enlargement: Results from the Pericardial Surgical Aortic Valve Replacement Pivotal Trial: A multicenter, prospective clinical trial.

Objective: During surgical aortic valve replacement, prosthesis-patient mismatch is avoided by implanting the largest possible valve, which sometimes requires annular enlargement (ARE). The effects of ARE on mortality remain controversial. We reviewed data from a multinational clinical trial evaluating a novel pericardial bioprosthesis to determine the influence of ARE 5 years postimplant. Methods: Patients with aortic valve disease requiring surgical aortic valve replacement were prospectively enrolled at 25 centers in North America and 13 centers in Europe. Standardized follow-up was prescribed, including serial echocardiography assessed by a core lab. A composite 30-day end point of major morbidity or mortality was defined as death, reoperation for any cause, stroke, deep sternal wound infection, and acute kidney injury. Results: Among 602 patients with detailed intraoperative data, 90 (15%) underwent ARE with similar rates in North America (17%) and Europe (12%; P = .11). Implanted valve size was similar in both groups (P = .18). The prevalence of moderate or severe prosthesis-patient mismatch at 12 months and at 5 years was comparable between groups, as was the average indexed effective orifice area (P = .3). Five-year survival (ARE, 91% vs no ARE, 89%) and freedom from 30-day major morbidity and mortality (ARE, 87% vs no ARE, 89%) were also similar. Conclusions: In this analysis of a prospective, observational clinical trial, we observed that the performance of an aortic root enlargement procedure did not increase morbidity or mortality at 30 days. We found that survival at 5 years was similar between groups, suggesting that the performance of an ARE procedure restored survival to that observed in patients who did not require an ARE.

Perioperative care differences of surgical aortic valve replacement between North America and Europe.

OBJECTIVE: To describe differences between North America and Europe in the perioperative management of patients undergoing surgical aortic valve replacement (SAVR). METHODS: Patients with moderate or greater aortic stenosis or regurgitation requiring SAVR were enrolled in a prospective observational cohort evaluating the safety and efficacy of a new stented bioprosthesis at 25 centres in North America (Canada and the USA) and 13 centres in Europe (Germany, the Netherlands, France, the UK, Switzerland and Italy). While all patients underwent implantation with the same bioprosthetic model, perioperative management was left to the discretion of participating centres. Perioperative care was described in detail including outcomes up to 1-year follow-up. RESULTS: Among 1118 patients, 643 (58%) were implanted in North America, and 475 (42%) were implanted in Europe. Patients in Europe were older, had a lower body mass index, less bicuspid disease and worse degree of aortic stenosis at baseline. In Europe, anticoagulant therapy at discharge was more aggressive, whereas length of stay was longer, and discharges directly to home were less common. Rehospitalisation risk was lower in Europe at 30 days (8.5% vs 15.9%) but converged at 1-year follow-up (26.5% vs 28.1%). Within continents, there were major differences between individual countries concerning perioperative management. CONCLUSION: Contemporary perioperative management of SAVR patients varies between North America and Europe in patient selection, procedural techniques, antithrombotic regimen and discharge management. Furthermore, rehospitalisation differed largely between continents and countries. Hence, geographical setting must be considered during design and interpretation of trials on SAVR. TRIAL REGISTRATION NUMBER: NCT02088554.

Pledgeted versus nonpledgeted sutures in aortic valve replacement: Insights from a prospective multicenter trial.

Objective: The objective of this study was to compare short- and midterm clinical and echocardiographic outcomes according to the use of pledgeted sutures during aortic valve replacement. Methods: Patients with aortic stenosis or regurgitation requiring aortic valve replacement were enrolled in a prospective cohort study to evaluate the safety of a new stented bioprosthesis. Outcomes were analyzed according to the use of pledgets (pledgeted group) or no pledgets (nonpledgeted group). The primary outcome was a composite of thromboembolism, endocarditis, and major paravalvular leak at 5 years of follow-up. Secondary outcomes included multiple clinical endpoints and hemodynamic outcomes. Propensity score matching was performed to adjust for prognostic factors, and subanalyses with small valve sizes (<23 mm) and suturing techniques were performed. Results: The pledgeted group comprised 640 patients (59%), and the nonpledgeted group 442 (41%), with baseline discrepancies in demographic characteristics, comorbidities, and stenosis severity. There were no differences between groups in any outcome. After propensity score matching, the primary outcome occurred in 41 (11.7%) patients in the pledgeted and 36 (9.8%) in the nonpledgeted group (P = .51). The effective orifice area was smaller in the pledgeted group (P = .045), whereas no difference was observed for the mean or peak pressure gradient. Separate subanalyses with small valve sizes and suturing techniques did not show relevant differences. Conclusions: In this large propensity score-matched cohort, comprehensive clinical outcomes were comparable between patients who underwent aortic valve replacement with pledgeted and nonpledgeted sutures up to 5 years of follow-up, but pledgets might lead to a slightly smaller effective orifice area in the long run.

A roadmap for ladybird conservation and recovery.

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.

Las catarinas (Coleoptera: Coccinellidae) proporcionan servicios que son críticos para la producción de alimento, y juegan un papel ecológico como fuente de alimento para depredadores. Sin embargo, la riqueza, abundancia y distribución de catarinas están en peligro debido a muchas amenazas antropogénicas. La carencia de conocimiento sobre el estatus de conservación de la mayoría de las especies y los factores que inciden en su dinámica poblacional dificulta el desarrollo e implementación de estrategias de conservación para las catarinas. Realizamos una revisión de la literatura sobre la ecología, diversidad y conservación de catarinas para identificar sus amenazas ecológicas clave. Las poblaciones de catarinas fueron afectadas mayormente por factores climáticos, composición del paisaje e invasiones biológicas. Proponemos acciones de mitigación para la conservación y recuperación de catarinas. Acciones a corto plazo incluyen programas de ciencia y educación ciudadana, medidas de protección para la recuperación de hábitat y de especies amenazadas, prevención de la introducción de especies no nativas y el mantenimiento y restauración de áreas naturales y la heterogeneidad del paisaje. Acciones a mediano plazo implican el análisis de datos obtenidos de programas de monitoreo y colecciones de insectos para desenmarañar el efecto de las diferentes amenazas a las poblaciones de catarinas, comprender el uso del hábitat por taxa de los que se tiene conocimiento limitado y cuantifica las tendencias temporales de la abundancia, diversidad y biomasa a lo largo de un gradiente de intensidad de manejo. Acciones a largo plazo incluyen el desarrollo de un programa de monitoreo a nivel mundial basado en muestreos estandarizados para subsanar la falta de datos, incrementar el poder explicativo, optimizar los análisis y facilitar colaboraciones globales.

Minimally Invasive Aortic Valve Replacement in Contemporary Practice: Clinical and Hemodynamic Performance from a Prospective Multicenter Trial.

BACKGROUND: The advent of transcatheter aortic valve replacement (AVR) has led to an increased emphasis on reducing the invasiveness of surgical procedures. The aim of this study was to evaluate clinical outcomes and hemodynamic performance achieved with minimally invasive aortic valve replacement (MI-AVR) as compared with conventional AVR. METHODS: Patients who underwent surgical AVR with the Avalus bioprosthesis, as part of a prospective multicenter non-randomized trial, were included in this analysis. Surgical approach was left to the discretion of the surgeons. Patient characteristics and clinical outcomes were compared between MI-AVR and conventional AVR groups in the entire cohort (n = 1077) and in an isolated AVR subcohort (n = 528). Propensity score adjustment was performed to estimate the effect of MI-AVR on adverse events. RESULTS: Patients treated with MI-AVR were younger, had lower STS scores, and underwent concomitant procedures less often. Valve size implanted was comparable between the groups. MI-AVR was associated with longer procedural times in the isolated AVR subcohort. Postprocedural hemodynamic performance was comparable. There were no significant differences between MI-AVR and conventional AVR in early and 3-year all-cause mortality, thromboembolism, reintervention, or a composite of those endpoints within either the entire cohort or the isolated AVR subcohort. After propensity score adjustment, there remained no association between MI-AVR and the composite endpoint (hazard ratio: 0.86, 95% confidence interval: 0.47-1.55, p = 0.61). CONCLUSION: Three-year outcomes after MI-AVR with the Avalus bioprosthetic valve were comparable to conventional AVR. These results provide important insights into the overall ability to reduce the invasiveness of AVR without compromising outcomes.

The robustness of the flow-gradient classification of severe aortic stenosis.

Objectives: A flow-gradient classification is used to determine the indication for intervention for patients with severe aortic stenosis (AS) with discordant echocardiographic parameters. We investigated the agreement in flow-gradient classification by stroke volume (SV) measurement at the left ventricular outflow tract (LVOT) and at the left ventricle. Methods: Data were used from a prospective cohort study and patients with severe AS (aortic valve area index ≤0.6 cm2/m2) with preserved ejection fraction (>50%) were selected. SV was determined by an echocardiographic core laboratory at the LVOT and by subtracting the 2-dimensional left ventricle end-systolic from the end-diastolic volume (volumetric). Patients were stratified into 4 groups based on SV index (35 mL/m2) and mean gradient (40 mm Hg). The group composition was compared and the agreement between the SV measurements was investigated using regression, correlation, and limits of agreement. In addition, a systematic LVOT diameter overestimation of 1 mm was simulated to study flow-gradient reclassification. Results: Of 1118 patients, 699 were eligible. The group composition changed considerably as agreement on flow state occurred in only 50% of the measurements. LVOT SV was on average 15.1 mL (95% limits of agreement -24.9:55.1 mL) greater than volumetric SV. When a systematic 1-mm LVOT diameter overestimation was introduced, the low-flow groups halved. Conclusions: There was poor agreement in the flow-gradient classification of severe AS as a result of large differences between LVOT and volumetric SV. Furthermore, this classification was sensitive to small measurement errors. These results stress that parameters beyond the flow-gradient classification should be considered to ensure accurate recommendations for intervention.

The Effect of Phenotype and Genotype on the Plasma Proteome in Patients with Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Protein profiling in patients with inflammatory bowel diseases [IBD] for diagnostic and therapeutic purposes is underexplored. This study analysed the association between phenotype, genotype, and the plasma proteome in IBD. METHODS: A total of 92 inflammation-related proteins were quantified in plasma of 1028 patients with IBD (567 Crohn's disease [CD]; 461 ulcerative colitis [UC]) and 148 healthy individuals to assess protein-phenotype associations. Corresponding whole-exome sequencing and global screening array data of 919 patients with IBD were included to analyse the effect of genetics on protein levels (protein quantitative trait loci [pQTL] analysis). Intestinal mucosal RNA sequencing and faecal metagenomic data were used for complementary analyses. RESULTS: Thirty-two proteins were differentially abundant between IBD and healthy individuals, of which 22 proteins were independent of active inflammation; 69 proteins were associated with 15 demographic and clinical factors. Fibroblast growth factor-19 levels were decreased in CD patients with ileal disease or a history of ileocecal resection. Thirteen novel cis-pQTLs were identified and 10 replicated from previous studies. One trans-pQTL of the fucosyltransferase 2 [FUT2] gene [rs602662] and two independent cis-pQTLs of C-C motif chemokine 25 [CCL25] affected plasma CCL25 levels. Intestinal gene expression data revealed an overlapping cis-expression [e]QTL-variant [rs3745387] of the CCL25 gene. The FUT2 rs602662 trans-pQTL was associated with reduced abundances of faecal butyrate-producing bacteria. CONCLUSIONS: This study shows that genotype and multiple disease phenotypes strongly associate with the plasma inflammatory proteome in IBD, and identifies disease-associated pathways that may help to improve disease management in the future.

Why the categorization of indexed effective orifice area is not justified for the classification of prosthesis-patient mismatch.

OBJECTIVES: Although the impact of prosthesis-patient mismatch (PPM) on survival has been widely studied, there has been little debate about whether the current definition of PPM truly reflects hemodynamic obstruction. This study aimed to validate the categorization of indexed effective orifice area (EOAi) for the classification of PPM. METHODS: In total, 2171 patients who underwent aortic valve replacement with a surgical stented bioprosthesis in 5 trials (CoreValve US High-Risk, SURTAVI [Surgical Replacement and Transcatheter Aortic Valve Implantation Trial], Evolut Low Risk, PERIGON [PERIcardial SurGical AOrtic Valve ReplacemeNt] Pivotal Trial for the Avalus valve, and PERIGON Japan) were used for this analysis. The echocardiographic images at the 1-year follow-up visit were evaluated to explore the association between EOAi and mean aortic gradient and its interaction with other patient characteristics, including obesity. In addition, different criteria of PPM were compared with reflect elevated mean aortic gradients (≥20 mm Hg). RESULTS: A relatively smaller exponential decay in mean aortic gradient was found for increasing EOAi, as the slope on the log scale was -0.83 versus -2.5 in the publication from which the current cut-offs for PPM originate. The accuracy of the American Society of Echocardiography, Valve Academic Research Consortium-2, and European Association of Cardiovascular Imaging definitions of PPM to reflect elevated mean aortic gradients was 49%, 57%, and 57%, respectively. The relation between EOAi and mean aortic gradient was not significantly different between obese and non-obese patients (P = .20). CONCLUSIONS: The use of EOAi thresholds to classify patients with PPM is undermined by a less-pronounced exponential relationship between EOAi and mean aortic gradient than previously demonstrated. Moreover, recent adjustment for obesity in the definition of PPM is not supported by these data.

Climate-driven, but dynamic and complex? A reconciliation of competing hypotheses for species' distributions.

Estimates of the percentage of species "committed to extinction" by climate change range from 15% to 37%. The question is whether factors other than climate need to be included in models predicting species' range change. We created demographic range models that include climate vs. climate-plus-competition, evaluating their influence on the geographic distribution of Pinus edulis, a pine endemic to the semiarid southwestern U.S. Analyses of data on 23,426 trees in 1941 forest inventory plots support the inclusion of competition in range models. However, climate and competition together only partially explain this species' distribution. Instead, the evidence suggests that climate affects other range-limiting processes, including landscape-scale, spatial processes such as disturbances and antagonistic biotic interactions. Complex effects of climate on species distributions-through indirect effects, interactions, and feedbacks-are likely to cause sudden changes in abundance and distribution that are not predictable from a climate-only perspective.

Polygenetic risk scores do not add predictive power to clinical models for response to anti-TNFα therapy in inflammatory bowel disease.

BACKGROUND: Anti-tumour necrosis factor alpha (TNFα) therapy is widely used in the management of Crohn's disease (CD) and ulcerative colitis (UC). However, up to a third of patients do not respond to induction therapy and another third of patients lose response over time. To aid patient stratification, polygenetic risk scores have been identified as predictors of response to anti-TNFα therapy. We aimed to replicate the association between polygenetic risk scores and response to anti-TNFα therapy in an independent cohort of patients, to establish its clinical validity. MATERIALS AND METHODS: Primary non-response, primary response, durable response and loss of response to anti-TNFα therapy was retrospectively assessed for each patient using stringent definitions. Genome wide genotyping was performed and previously described polygenetic risk scores for primary non-response and durable response were calculated. We compared polygenetic risk scores between patients with primary response and primary non-response, and between patients with durable response and loss of response, using separate analyses for CD and UC. RESULTS: Out of 334 patients with CD, 15 (4%) patients met criteria for primary non-response, 221 (66%) for primary response, 115 (34%) for durable response and 35 (10%) for loss of response. Out of 112 patients with UC, 12 (11%) met criteria for primary non-response, 68 (61%) for primary response, 19 (17%) for durable response and 20 (18%) for loss of response. No significant differences in polygenetic risk scores were found between primary non-responders and primary responders, and between durable responders and loss of responders. CONCLUSIONS: We could not replicate the previously reported association between polygenetic risk scores and response to anti-TNFα therapy in an independent cohort of patients with CD or UC. Currently, there is insufficient evidence to use polygenetic risk scores to predict response to anti-TNFα therapy in patients with IBD.

Inflammation status modulates the effect of host genetic variation on intestinal gene expression in inflammatory bowel disease.

More than 240 genetic risk loci have been associated with inflammatory bowel disease (IBD), but little is known about how they contribute to disease development in involved tissue. Here, we hypothesized that host genetic variation affects gene expression in an inflammation-dependent way, and investigated 299 snap-frozen intestinal biopsies from inflamed and non-inflamed mucosa from 171 IBD patients. RNA-sequencing was performed, and genotypes were determined using whole exome sequencing and genome wide genotyping. In total, 28,746 genes and 6,894,979 SNPs were included. Linear mixed models identified 8,881 independent intestinal cis-expression quantitative trait loci (cis-eQTLs) (FDR < 0.05) and interaction analysis revealed 190 inflammation-dependent intestinal cis-eQTLs (FDR < 0.05), including known IBD-risk genes and genes encoding immune-cell receptors and antibodies. The inflammation-dependent cis-eQTL SNPs (eSNPs) mainly interact with prevalence of immune cell types. Inflammation-dependent intestinal cis-eQTLs reveal genetic susceptibility under inflammatory conditions that can help identify the cell types involved in and the pathways underlying inflammation, knowledge that may guide future drug development and profile patients for precision medicine in IBD.