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Differentiating amyloid light-chain (AL) from transthyretin-related cardiac amyloidoses (ATTR) is imperative given implications for prognosis, therapy, and genetic counseling. We validated the discriminatory ability of 99mTc-pyrophosphate (99mTc-PYP) scintigraphy in AL versus ATTR.Forty-five subjects (12 AL, 16 ATTR wild type, and 17 ATTR mutants) underwent 99mTc-PYP planar and single-photon positive emission computed tomography cardiac imaging. Scans were performed by experienced nuclear cardiologists blinded to the subjects’ cohort assignment. Cardiac retention was assessed with both a semiquantitative visual score (range, 0; no uptake to 3, diffuse uptake) and by quantitative analysis by drawing a region of interest over the heart corrected for contralateral counts and calculating a heart-to-contralateral ratio. Subjects with ATTR cardiac amyloid had a significantly higher semiquantitative cardiac visual score than the AL cohort (2.9±0.06 versus 0.8±0.27; P<0.0001) as well as a higher quantitative score (1.80±0.04 versus 1.21±0.04; P<0.0001). Using a heart-to-contralateral ratio >1.5 consistent with intensely diffuse myocardial tracer retention had a 97% sensitivity and 100% specificity with area under the curve 0.992, P<0.0001 for identifying ATTR cardiac amyloidosis.99mTc-PYP cardiac imaging distinguishes AL from ATTR cardiac amyloidosis and may be a simple, widely available method for identifying subjects with ATTR cardiac amyloidosis, which should be studied in a larger prospective manner. [ABSTRACT FROM AUTHOR]

Background: Donor-derived cell-free DNA (dd-cfDNA) has emerged as a reliable, noninvasive method for the surveillance of allograft rejection in heart transplantation (HT) patients, but its utility in multi-organ transplants (MOT) is unknown. We describe our experience using dd-cfDNA in simultaneous MOT recipients., Methods: A single-center retrospective review of all HT recipients between 2018 and 2022 that had at least one measurement of dd-cfDNA collected. Patients who had simultaneous MOT were identified and included in this study. Levels of dd-cfDNA were paired with endomyocardial biopsies (EMB) performed within 1 month of blood testing if available. Acute cellular rejection (ACR) was defined as ISHLT (International Society for Heart and Lung Transplantation) grade ≥ 2R. and antibody-mediated rejection (AMR) was defined as pAMR grade > 0. The within-patient variability score of the dd-cfDNA was calculated by the variance/average., Results: The study included 25 multiorgan transplant recipients: 13 heart-kidney (H-K), 8 heart-liver (H-Li), and 4 heart-lung (H-Lu). The median age was 55 years, 44% were female; the median time from HT until the first dd-cfDNA measurement was 4.5 months (IQR 2, 10.5). The median dd-cfDNA level was 0.18% (IQR 0.15%, 0.27%) for H-K, 1.15% (IQR 0.77%, 2.33%) for H-Li, and 0.69% (IQR 0.62%, 1.07%) for H-Lu patients (p < 0.001). Prevalence of positive dd-cfDNA tests (threshold of 0.20%) were 42.2%, 97.3%, and 92.3% in the H-K, H-Li, and H-Lu groups, respectively. The within-patient variability score was highest in the H-Li group (median of 0.45 [IQR 0.29, 0.94]) and lowest in the H-K group (median of 0.09 [IQR 0.06, 0.12]); p = 0.002. No evidence of cardiac ACR or AMR was found. Three patients experienced renal allograft ACR and/or AMR, two patients experienced rejection of the liver allograft, and one patient experienced an episode of AMR-mediated lung rejection. One person in the H-K group experienced an episode of cardiac allograft dysfunction that was not associated with biopsy-confirmed rejection., Conclusion: Dd-cfDNA is chronically elevated in most MOT recipients. There is a high degree of within-patient variability in levels (particularly for H-Li and H-Lu recipients), which may limit the utility of this assay in monitoring MOT recipients., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: To evaluate the clinical implications of adjunctive molecular gene expression analysis (MMDx ) of biopsy specimens in heart transplant (HT ) recipients with suspected rejection., Introduction: Histopathological evaluation remains the standard method for rejection diagnosis in HT. However, the wide interobserver variability combined with a relatively common incidence of "biopsy-negative" rejection has raised concerns about the likelihood of false-negative results. MMDx, which uses gene expression to detect early signs of rejection, is a promising test to further refine the assessment of HT rejection., Methods: Single-center prospective study of 418 consecutive for-cause endomyocardial biopsies performed between November 2022 and May 2024. Each biopsy was graded based on histology and assessed for rejection patterns using MMDx. MMDx results were deemed positive if borderline or definitive rejection was present. The impact of MMDx results on clinical management was evaluated. Primary outcomes were 1-year survival and graft dysfunction following MMDx-guided clinical management. Secondary outcomes included changes in donor-specific antibodies, MMDx gene transcripts, and donor-derived cell-free DNA (dd-cfDNA) levels., Results: We analyzed 418 molecular samples from 237 unique patients. Histology identified rejection in 32 cases (7.7%), while MMDx identified rejection in 95 cases (22.7%). Notably, in 79 of the 95 cases where MMDx identified rejection, histology results were negative, with the majority of these cases being antibody-mediated rejection (62.1%). Samples with rejection on MMDx were more likely to show a combined elevation of dd-cfDNA and peripheral blood gene expression profiling than those with borderline or negative MMDx results (36.7% vs 28.0% vs 10.3%; p<0.001). MMDx results led to the implementation of specific antirejection protocols or changes in immunosuppression in 20.4% of cases, and in 73.4% of cases where histology was negative and MMDx showed rejection. 1-year survival was better in the positive MMDx group where clinical management was guided by MMDx results (87.0% vs 78.6%; log rank p=0.0017)., Conclusions: In our cohort, MMDx results more frequently indicated rejection than histology, often leading to the initiation of antirejection treatment. Intervention guided by positive MMDx results was associated with improved outcomes.

Young adult solid organ transplant recipients who transfer from pediatric to adult care experience poor outcomes related to decreased adherence to the medical regimen. Our pilot trial for young adults who had heart transplant (HT) who transfer to adult care tests an intervention focused on increasing HT knowledge, self-management and self-advocacy skills, and enhancing support, as compared to usual care. We report baseline findings between groups regarding (1) patient-level outcomes and (2) components of the intervention. From 3/14 to 9/16, 88 subjects enrolled and randomized to intervention (n = 43) or usual care (n = 45) at six pediatric HT centers. Patient self-report questionnaires and medical records data were collected at baseline, and 3 and 6 months after transfer. For this report, baseline findings (at enrollment and prior to transfer to adult care) were analyzed using Chi-square and t-tests. Level of significance was p < 0.05. Baseline demographics were similar in the intervention and usual care arms: age 21.3 ± 3.2 vs 21.5 ± 3.3 years and female 44% vs 49%, respectively. At baseline, there were no differences between intervention and usual care for use of tacrolimus (70 vs 62%); tacrolimus level (mean ± SD = 6.5 ± 2.3 ng/ml vs 5.6 ± 2.3 ng/ml); average of the within patient standard deviation of the baseline mean tacrolimus levels (1.6 vs 1.3); and adherence to the medical regimen [3.6 ± 0.4 vs 3.5 ± 0.5 (1 = hardly ever to 4 = all of the time)], respectively. At baseline, both groups had a modest amount of HT knowledge, were learning self-management and self-advocacy, and perceived they were adequately supported. Baseline findings indicate that transitioning HT recipients lack essential knowledge about HT and have incomplete self-management and self-advocacy skills.