| 1. |
- Zar, Gustav, et al.
(författare)
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Whole-genome sequencing based on formalin-fixed paraffin-embedded endomyocardial biopsies for genetic studies on outcomes after heart transplantation
- 2019
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- Background Whole-genome sequencing (WGS) of heart transplant recipient- and donor-derived cardiac biopsies may facilitate organ matching, graft failure prediction, and immunotolerance research. The objective of this study was to determine the feasibility of WGS based on formalin-fixed paraffin-embedded endomyocardial biopsies. Methods and results The study included serial donor- and recipient samples from patients who had undergone heart transplantation at Skane University Hospital, Lund, Sweden, between 1988 and 2009. DNA extraction and WGS were conducted. Additional WGS sequencing quality metrics and coverage were obtained with the Genome Analysis Toolkit (GATK). 455 endomyocardial samples from 37 heart transplant recipients were acquired from routine rejection monitoring and stored as formalin-fixed paraffin-embedded samples. They were analyzed after 3–26 years of storage. DNA was extracted from 114 samples and WGS was run on 85 samples. DNA extraction yielded 313 ng (IQR 96–601) for all samples. A coverage of 11.3x (IQR 9.0–15.9) was recorded for all WGS samples. Three samples stored for > 25 years yielded a coverage of > 25x. Data were generated for 1.7 billion reads per sample (IQR 1.4–2.7). A Transition/Transversion (TiTv) ratio of 2.09 ± 0.05 was calculated for all WGS samples. No associations were found among storage time, DNA yield, or sequencing quality metrics. Conclusions The present study demonstrated the feasibility of whole-genome sequencing based on endomyocardial biopsies. This process could enable large-scale retrospective genomic studies using stored histopathological samples.
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| 2. |
- Pimpalwar, Neha, et al.
(författare)
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Methods for isolation and transcriptional profiling of individual cells from the human heart
- 2020
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Ingår i: Heliyon. - : Elsevier BV. - 2405-8440. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Global transcriptional profiling of individual cells represents a powerful approach to systematically survey contributions from cell-specific molecular phenotypes to human disease states but requires tissue-specific protocols. Here we sought to comprehensively evaluate protocols for single cell isolation and transcriptional profiling from heart tissue, focusing particularly on frozen tissue which is necessary for study of human hearts at scale. Methods and results: Using flow cytometry and high-content screening, we found that enzymatic dissociation of fresh murine heart tissue resulted in a sufficient yield of intact cells while for frozen murine or human heart resulted in low-quality cell suspensions across a range of protocols. These findings were consistent across enzymatic digestion protocols and whether samples were snap-frozen or treated with RNA-stabilizing agents before freezing. In contrast, we show that isolation of cardiac nuclei from frozen hearts results in a high yield of intact nuclei, and leverage expression arrays to show that nuclear transcriptomes reliably represent the cytoplasmic and whole-cell transcriptomes of the major cardiac cell types. Furthermore, coupling of nuclear isolation to PCM1-gated flow cytometry facilitated specific cardiomyocyte depletion, expanding resolution of the cardiac transcriptome beyond bulk tissue transcriptomes which were most strongly correlated with PCM1(+) transcriptomes (r = 0.8). We applied these methods to generate a transcriptional catalogue of human cardiac cells by droplet-based RNA-sequencing of 8,460 nuclei from which cellular identities were inferred. Reproducibility of identified clusters was confirmed in an independent biopsy (4,760 additional PCM1(-) nuclei) from the same human heart. Conclusion: Our results confirm the validity of single-nucleus but not single-cell isolation for transcriptional profiling of individual cells from frozen heart tissue, and establishes PCM1-gating as an efficient tool for cardiomyocyte depletion. In addition, our results provide a perspective of cell types inferred from single-nucleus transcriptomes that are present in an adult human heart.
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| 3. |
- Gjesdal, Grunde, et al.
(författare)
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Validation of cause of death classification after heart transplantation and cause-specific life expectancy compared to the general population
- 2022
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Ingår i: Clinical Transplantation. - : Wiley. - 0902-0063 .- 1399-0012. ; 36:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Post heart-transplant survival has increased, but information is lacking on specific causes of death and life expectancy. We aimed to assess cause-specific loss of life-years compared to the general population, evaluate classification for cause of death after heart transplantation, and assess validity of cause of death data from the International Society of Heart and Lung Transplant (ISHLT) registry. Methods: In this single center study, we included 239 heart recipients transplanted between 1988 and 2019 in Lund, Sweden (n = 239, 50% of the transplanted population where the cause of death was available). Two cardiologists retrospectively assigned causes of death according to a published classification (CLASS) in the 91 recipients who died during follow-up. Life expectancy was compared to data from the general population. Results: Compared to the average Swedish population, life expectancy for heart transplant recipients was 20 years shorter (IQR 12.9–27.2). The largest number of life-years lost were for deaths due to acute (49 years) and chronic rejection (27 years). Primary graft dysfunction (24 years) accounted for 24% of deaths, followed by malignancy (20 years) and infection (17 years), each accounting for ∼20% of deaths. Use of CLASS revealed moderate inter-rater agreement (56%) and moderate agreement with the ISHLT registry (62%). Conclusions: Survival after heart transplantation was 20 years lower than in the general population. In the young, more life-years were lost due to acute graft rejection, whereas chronic graft rejection and primary graft failure were more important causes of death in older patients. Agreement was moderate between CLASS and the ISHLT registry classifications.
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| 4. |
- Ingvarsson, Annika, et al.
(författare)
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Impact of gender on echocardiographic characteristics in heart transplant recipients
- 2019
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:4, s. 246-254
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Assessment following heart transplantation (HTx) is routinely performed using transthoracic echocardiography. Differences in long-term mortality following HTx related to donor-recipient matching have been reported, but effects of gender on cardiac size and function are not well studied. The aims of this study were to evaluate differences in echocardiographic characteristics of HTx recipients defined by gender. Methods and results: The study prospectively enrolled 123 (n = 34 female) HTx recipients of which 23 recipients was donor-recipient gender mismatched. Patients were examined with 2-dimensional echocardiography using Philips iE33 ultrasound system. Data were analysed across strata based on recipient gender and gender mismatch. Male recipients had larger left ventricular (LV) mass, thicker septal wall (P<0·001) and larger absolute LV volumes (P<0·001). Mean LV ejection fraction (EF) was higher in females (P<0·05), but no differences in conventional parameters of right ventricular (RV) function were found. Ventricular strain was higher in females than in males: LV global longitudinal strain (P<0·01), RV global longitudinal strain (P<0·05) and RV lateral free wall (P<0·05). The male group receiving a female donor heart had comparable EF and strain parameters to the female group receiving a gender-matched heart. Conclusion: We found that female recipient gender was associated with smaller chamber size, higher LV EF and better LV and RV longitudinal strain. Gender-mismatched male recipients appeared to exhibit function parameters similar to gender-matched female recipients. Our results indicate that the gender aspect, analogous to current reference guidelines in general population, should be taken into consideration when examining patients post-HTx.
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| 5. |
- Ingvarsson, Annika, et al.
(författare)
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Normal Reference Ranges for Transthoracic Echocardiography Following Heart Transplantation
- 2018
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Ingår i: Journal of the American Society of Echocardiography. - : Elsevier BV. - 0894-7317. ; 31:3, s. 349-360
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Tidskriftsartikel (refereegranskat)abstract
- Background: Heart function following heart transplantation (HTx) is influenced by numerous factors. It is typically evaluated using transthoracic echocardiography, but reference values are currently unavailable for this context. The primary aim of the present study was to derive echocardiographic reference values for chamber size and function, including cardiac mechanics, in clinically stable HTx patients. Methods: The study enrolled 124 healthy HTx patients examined prospectively. Patients underwent comprehensive two-dimensional echocardiographic examinations according to contemporary guidelines. Results were compared with recognized reference values for healthy subjects. Results: Compared with guidelines, larger atrial dimensions were seen in HTx patients. Left ventricular (LV) diastolic volume was smaller, and LV wall thickness was increased. With respect to LV function, both ejection fraction (62 ± 7%, P < .01) and global longitudinal strain (-16.5 ± 3.3%, P < .0001) were lower. All measures of right ventricular (RV) size were greater than reference values (P < .0001), and all measures of RV function were reduced (tricuspid annular plane systolic excursion 15 ± 4 mm [. P < .0001], RV systolic tissue Doppler velocity 10 ± 6 cm/sec [. P < .0001], fractional area change 40 ± 8% [. P < .0001], and RV free wall strain -16.9 ± 4.2% [. P < .0001]). Ejection fraction and LV global longitudinal strain were significantly lower in patients with previous rejection. Conclusion: The findings of this study indicate that the distribution of routinely used echocardiographic measures differs between stable HTx patients and healthy subjects. In particular, markedly larger RV and atrial volumes and mild reductions in both LV and RV longitudinal strain were evident. The observed differences could be clinically relevant in the assessment of HTx patients, and specific reference values should be applied in this context.
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| 6. |
- Jernryd, Victoria, et al.
(författare)
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Myocardial injury biomarkers at point of care for early identification of primary graft dysfunction after heart transplantation.
- 2022
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Ingår i: Clinical transplantation. - : Wiley. - 1399-0012 .- 0902-0063. ; 36:2
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Tidskriftsartikel (refereegranskat)abstract
- Primary graft dysfunction (PGD) is a leading cause of 30- day mortality following heart transplantation, and early intervention in PGD may correlate to improved survival. Our analysis aimed to determine the feasibility of measuring cardiac biomarkers from the donor heart in the early phase for use as a predictor of PGD.Blood samples from the coronary sinus were obtained at the time of transplantation in hearts preserved by cold static storage. The samples were analyzed for CK-MB and cTnI with a point-of-care method. The primary outcome was severe PGD or the need for veno-arterial extracorporeal membrane oxygenation within 7 days, referred to as severe graft dysfunction.Of the total cohort (n = 63), eight patients (13%) were diagnosed with severe graft dysfunction within 7 days. Patients with high CK-MB had an increased risk for severe graft dysfunction with unadjusted Odds Ratio (OR) of 4.5 (95%CI 0.96-21.11 p = 0.057) and adjusted OR of 7.4 (95%CI 1.13-48.46, p = 0.037. Similar but non Clinical Transplantation For Review Only significant trends were observed for cTnI.By measuring CK-MB from the coronary effluent in the donor heart, it may be possible to identify patients at increased risk for severe PGD after heart transplantation. This article is protected by copyright. All rights reserved.
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| 7. |
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| 8. |
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| 9. |
- Nilsson, Johan, et al.
(författare)
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Human Leukocyte Antigen-Based Risk Stratification in Heart Transplant Recipients-Implications for Targeted Surveillance
- 2019
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Ingår i: Journal of the American Heart Association. - 2047-9980. ; 8:15
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Tidskriftsartikel (refereegranskat)abstract
- Background Human leukocyte antigen (HLA) matching isn't routinely performed in heart transplantation. Novel allograft perfusion methods may make HLA matching feasible. The purpose of this study is to reexamine whether HLA mismatch may be used in risk stratification to improve outcomes in heart transplantation. Methods and Results We analyzed 34 681 recipients undergoing heart transplantation between 1987 and 2013. We used HLAMatchmaker to quantify HLA eplet mismatches and Cox regression for analysis of time to graft loss. Recipients with 4 mismatched HLA-DR/DQ alleles and >40 eplets reached an adjusted hazard ratio (HR) for graft loss of 1.17 (95% CI 1.07-1.28) and 1.11 (95% CI 1.03-1.21), respectively. We found significant interaction between recipient age and numbers of HLA-DR/DQ allele and eplet mismatches resulting in an adjusted HR of 1.78 (95% 1.13-2.80) and 1.82 (95% CI, 1.23-2.70), respectively. HR for both interaction terms was 0.99 (95% CI, 0.98-1.00). Risk of graft loss was more pronounced after 1 year, where recipient <40 years with 4 mismatched HLA-DR/DQ alleles and >40 eplets had an adjusted HR of 1.51 (95% CI 1.12-2.03) and 1.32 (95% CI 1.02-1.70), respectively. Pre-sensitized recipients with panel reactive antibodies >10% had an adjusted HR=1.27 (95% CI 1.16-1.40) for graft loss within 1 year but not thereafter. HLA eplet mismatch was independent of panel reactive antibodies on reduction of graft loss within and after 1 year, P (interaction)=0.888 and 0.389. Conclusions HLA mismatch may be used in risk stratification for intensified post-transplant surveillance and therapy.
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