Cardiac Transplant Rejection Research Articles

(313) - Durability of Bortezomib for Treatment of Antibody Mediated Rejection in Cardiac Transplantation

(313) - Durability of Bortezomib for Treatment of Antibody Mediated Rejection in Cardiac Transplantation

(63) - Role of Novel Cardiovascular Magnetic Resonance Based Tissue Characterization in the Detection of Cardiac Transplant Rejection

Role of Novel Cardiovascular Magnetic Resonance Based Tissue Characterization in the Detection of Cardiac Transplant Rejection M. Imran ,1 L. Wang,1 J. McCrohon,1 C. Yu,1 J. Huang,1 C. Holloway,1 O. James,2 C. Stehning,3 K. Moffat,4 J. Ross,4 E. Kotlyar,1 C. Hayward,1 A. Keogh,1 P. Macdonald,1 A. Jabbour.1 1Cardiology, St. Vincent`s Hospital, Sydney, Australia; 2Cardiology, Liverpool Hospital, Sydney, Australia; 3Philips GmbH Innovative Technologies, Philips, Hamburg, Germany; 4Medical Imaging, St. Vincent`s Hospital, Sydney, Australia.

Detecting rejection in cardiac transplantation: applications of genomic medicine.

The primary focus of care in heart transplant recipients is to prevent rejection. Checking serum levels of immunosuppressant drugs as well as performing biopsies to obtain tissue samples for histological analysis have been the mainstays of rejection surveillance. Novel applications of genomics have proven to be useful in adding a noninvasive alternative to the standard of care. In particular, the use of gene-expression profiling to detect upregulation of rejection-related genes, detection of donor-derived cell-free DNA as a marker of graft apoptosis and rejection, as well as mRNA and miRNA as intragraft and peripheral markers of rejection have come to the forefront of genomics as they relate to transplantation. This review focuses on the use of genomics in heart transplant recipients.

Multiparametric mapping in the diagnosis and management of cardiac transplant rejection: a prospective, histologically-validated study

Multiparametric mapping in the diagnosis and management of cardiac transplant rejection: a prospective, histologically-validated study

Tyrosine Kinase Inhibitor Discontinuation in Chronic Myeloid Leukemia: Single US Center Experience

Imatinib (IM) can be safely discontinued in patients with chronic myeloid leukemia (CML) with sustained complete molecular remission. Previous publications from France and Australia have shown that overall 40% maintain MMR or MR5 for up to 5 years after IM is stopped. We report single US center experience with tyrosine kinase inhibitor (TKI) discontinuation. Between 06/2010 and 7/2015, 22 patients with CML in chronic (CP, n=19), accelerated (AP, n=2) and lymphoid blast phase (LBP, n=1) discontinued IM (n=17), dasatinib (DAS, n=3) or bosutinib (BOS, n=2), and were monitored by qPCR for BCR-ABL1 monthly for the first 3 months, quarterly for the following 2 years and then bi-annually. TKI was restarted in case of confirmed loss of MMR on a repeat qPCR. Reason for TKI discontinuation was predominantly driven by patients' request and TKI intolerance. Median age was 66 (range, 21-84). The 3 who discontinued DAS had IM-resistant (loss of CCyR; n=1), IM-intolerant CP (n=1), or received DAS as first-line agent (n=1). BOS was discontinued for IM-intolerant CP (n=1), or while in CR2 in a patient with LBP that transformed from IM resistant CP and relapsed following chemotherapy (HCVAD). Median duration of TKI therapy pre-discontinuation for the entire cohort was 89 months (range, 26-106). Three patients are not evaluable due to short follow-up (TKI stopped between 5/2015 and 7/2015). With a median follow-up of 40 months (range, 8-60), 7 (41%, 6 CP and 1 AP), all previously on IM lost MMR a median of 3 months (range, 3-24) after TKI was stopped and restarted IM. Loss of CHR occurred 13 months after loss of MMR in 1 patient who elected not to restart IM at the time MMR was lost, due to complications from cardiac transplant rejection. All 7 achieved MMR following restart of IM. Median duration of TKI therapy pre-discontinuation for these 7 patients was 60 months (range, 48-98). 12 patients (59%, 10 CP, 1 AP, 1 LBP) remain off TKI and have not lost MMR, 8 with continuously undetectable BCR-ABL1; and 4 had 1-2 transient detectable BCR-ABL1 at MR4 levels. Median duration of TKI therapy pre-discontinuation for these 12 patients was 87 months (range, 26-106). Loss of MMR-free survival is depicted in the Figure. We conclude that, similar to previous reports, TKI can be safely discontinued in patients with CML without reappearance of BCR-ABL1 in 50-60%. Figure 1. Figure 1. Disclosures Jillella: Seattle Genetics, Inc.: Research Funding. Kota:Leukemia Lymphoma Society: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees.

Circulation : Clinical Summaries

<i>Circulation</i> : Clinical Summaries

HGF Guides T Cells into the Heart

Expression of distinct homing receptors guides adaptive immune cells to antigen-rich tissue. In this issue of Immunity, Komarowska et al. (2015) describe an autocrine loop that is initiated by cardiac-expressed hepatocyte growth factor to direct T cells into the heart during inflammation and cardiac transplant rejection.

Advances in the understanding and management of heart transplantation.

Cardiac transplantation represents one of the great triumphs in modern medicine and remains the cornerstone in the treatment of advanced heart failure. In this review, we contextualize pivotal developments in our understanding and management of cardiac transplant immunology, histopathology, rejection surveillance, drug development and surgery. We also discuss current limitations in their application and the impact of the left ventricular assist devices in bridging this gap.

Antibody-mediated rejection in cardiac transplantation: emerging knowledge in diagnosis and management: a scientific statement from the American Heart Association.

Antibody-mediated rejection (AMR) of the cardiac allograft is a poorly defined and challenging diagnosis for transplant recipients and their clinicians. Although even its very existence in heart transplantation was debated until relatively recently, improved immunopathologic and serological techniques to detect myocardial capillary complement deposition and circulating anti-HLA (human leukocyte antigen) antibodies have led to the detection of a spectrum of newly uncovered immunologic changes that characterize AMR. The earliest standardized clinical and pathological criteria for the diagnosis of AMR in heart transplantation became available in 2004, the result of a task force assembled by the International Society for Heart and Lung Transplantation (ISHLT). In 2006, the criteria were refined by the ISHLT Immunopathology Task Force (Table 1). These revisions provide 4 categories of diagnostic criteria: clinical, histopathologic, immunopathologic, and serological assessment.1 Despite these published criteria, currently >50% of heart transplant centers make the diagnosis of AMR based on cardiac dysfunction and the lack of cellular infiltrates on the heart biopsy (preconference survey included in the ISHLT consensus article).2 More recently, the ISHLT Consensus Conference on AMR has redefined the pathological diagnosis of AMR.3 The 2013 ISHLT “Working Formulation for the Standardization of Nomenclature in the Pathologic Diagnosis of Antibody-Mediated Rejection in Heart Transplantation” was published in December 2013. This document provided an update to the 2010 consensus conference.4 It is anticipated that this update to the definition of AMR will reduce variations in the diagnosis of AMR, providing a platform for the development of standardized therapies. The goal of the present scientific statement is to provide the heart transplant professional with an overview of the current status of the diagnosis and treatment of AMR in the cardiac allograft based on recent consensus conferences and the published literature. We include recommendations to facilitate evolving standardization and strategies …

Computational chemical imaging for cardiovascular pathology: chemical microscopic imaging accurately determines cardiac transplant rejection.

Rejection is a common problem after cardiac transplants leading to significant number of adverse events and deaths, particularly in the first year of transplantation. The gold standard to identify rejection is endomyocardial biopsy. This technique is complex, cumbersome and requires a lot of expertise in the correct interpretation of stained biopsy sections. Traditional histopathology cannot be used actively or quickly during cardiac interventions or surgery. Our objective was to develop a stain-less approach using an emerging technology, Fourier transform infrared (FT-IR) spectroscopic imaging to identify different components of cardiac tissue by their chemical and molecular basis aided by computer recognition, rather than by visual examination using optical microscopy. We studied this technique in assessment of cardiac transplant rejection to evaluate efficacy in an example of complex cardiovascular pathology. We recorded data from human cardiac transplant patients’ biopsies, used a Bayesian classification protocol and developed a visualization scheme to observe chemical differences without the need of stains or human supervision. Using receiver operating characteristic curves, we observed probabilities of detection greater than 95% for four out of five histological classes at 10% probability of false alarm at the cellular level while correctly identifying samples with the hallmarks of the immune response in all cases. The efficacy of manual examination can be significantly increased by observing the inherent biochemical changes in tissues, which enables us to achieve greater diagnostic confidence in an automated, label-free manner. We developed a computational pathology system that gives high contrast images and seems superior to traditional staining procedures. This study is a prelude to the development of real time in situ imaging systems, which can assist interventionists and surgeons actively during procedures.

(826) - Cardiomyocyte Cell Targets of Humoral Rejection in Cardiac Transplantation: Experimental Modeling in Rats

PurposeChronic rejection is the main long-term complication after cardiac transplantation in humans. The objective of this study is to understand the impact of the anti-MHC class I antibody response in myocyte function in vivo and in vitro myocyte survival.MethodsNine heterotopic heart transplants were performed between two incompatible strains of rats (Lewis LEW and Fisher FIS). The immune sera were obtained by successive FIS to LEW skin grafts. The LEW anti FIS alloantisera were transferred passively to LEW rats by intraperitoneal injections. Grafted hearts were evaluated by immunohistochemistry to day 3, day 9 (4 rats) and day 14. (5 rats).ResultsIn the group without humoral transfer (Day 14), intimal proliferation and a marked inflammatory infiltration of the media has been highlighted. The STAR72 marking showed the presence of IgG anti FIS within cardiomyocytes and TUNEL showed a phenomenon of cell death (apoptosis) of myocytes. The humoral transfer at day 3 and day 9 induced direct myocyte damage (presence of apoptosis in TUNEL) and lymphocytic infiltration in the heart parenchyma but less compared to the group without humoral transfer (day 14). Coronary artery graft was evident in all cases (9/9) with or without humoral transfer.ConclusionThe humoral transfer causes the onset of occlusive lesions in the coronary arteries but also a direct attack on the myocyte by anti-MHC I (apoptosis). PurposeChronic rejection is the main long-term complication after cardiac transplantation in humans. The objective of this study is to understand the impact of the anti-MHC class I antibody response in myocyte function in vivo and in vitro myocyte survival. Chronic rejection is the main long-term complication after cardiac transplantation in humans. The objective of this study is to understand the impact of the anti-MHC class I antibody response in myocyte function in vivo and in vitro myocyte survival. MethodsNine heterotopic heart transplants were performed between two incompatible strains of rats (Lewis LEW and Fisher FIS). The immune sera were obtained by successive FIS to LEW skin grafts. The LEW anti FIS alloantisera were transferred passively to LEW rats by intraperitoneal injections. Grafted hearts were evaluated by immunohistochemistry to day 3, day 9 (4 rats) and day 14. (5 rats). Nine heterotopic heart transplants were performed between two incompatible strains of rats (Lewis LEW and Fisher FIS). The immune sera were obtained by successive FIS to LEW skin grafts. The LEW anti FIS alloantisera were transferred passively to LEW rats by intraperitoneal injections. Grafted hearts were evaluated by immunohistochemistry to day 3, day 9 (4 rats) and day 14. (5 rats). ResultsIn the group without humoral transfer (Day 14), intimal proliferation and a marked inflammatory infiltration of the media has been highlighted. The STAR72 marking showed the presence of IgG anti FIS within cardiomyocytes and TUNEL showed a phenomenon of cell death (apoptosis) of myocytes. The humoral transfer at day 3 and day 9 induced direct myocyte damage (presence of apoptosis in TUNEL) and lymphocytic infiltration in the heart parenchyma but less compared to the group without humoral transfer (day 14). Coronary artery graft was evident in all cases (9/9) with or without humoral transfer. In the group without humoral transfer (Day 14), intimal proliferation and a marked inflammatory infiltration of the media has been highlighted. The STAR72 marking showed the presence of IgG anti FIS within cardiomyocytes and TUNEL showed a phenomenon of cell death (apoptosis) of myocytes. The humoral transfer at day 3 and day 9 induced direct myocyte damage (presence of apoptosis in TUNEL) and lymphocytic infiltration in the heart parenchyma but less compared to the group without humoral transfer (day 14). Coronary artery graft was evident in all cases (9/9) with or without humoral transfer. ConclusionThe humoral transfer causes the onset of occlusive lesions in the coronary arteries but also a direct attack on the myocyte by anti-MHC I (apoptosis). The humoral transfer causes the onset of occlusive lesions in the coronary arteries but also a direct attack on the myocyte by anti-MHC I (apoptosis).

Combination of C-X-C motif chemokine 9 and C-X-C motif chemokine 10 antibodies with FTY720 prolongs the survival of cardiac retransplantation allografts in a mouse model.

The upregulation of chemokine genes and the subsequent T-lymphocyte recruitment to the graft are early events in the development of acute cardiac transplant rejection or cardiac allograft vasculopathy. In the present study, a combined immunosuppressive regimen of C-X-C motif chemokine 9 (CXCL9) antibody (Ab), CXCL10 Ab and FTY720 was used in order to reduce the infiltration of memory T lymphocytes and prolong graft survival in a retransplantation murine model. BALB/c donor hearts were transplanted heterotopically into C57BL/6 mice at day 28 after skin transplantation. The mice were divided into four groups: i) Control (normal saline), ii) CXCL9 Ab and CXCL10 Ab [150 μg; once daily (qd); intraperitoneal (ip)], iii) FTY720 (0.2 mg/day; qd; ip) and iv) combined (2 mg/kg/day; qd; ip). Measurements of the median survival time of the cardiac grafts, histological examination, reverse transcription-quantitative polymerase chain reaction analysis, enzyme-linked immunosorbent assay and a mixed lymphocyte reaction were performed. The median graft survival time of the combined group was prolonged (9.3 days) compared with that of the control group (3.5 days) (P<0.001). Histological examination revealed that the combined treatment group graft rejection pathological score was 0.50, while the control group score was 3.62 (P<0.001). In addition, the gene expression level of interleukin (IL)-2 was significantly lower and the levels of IL-10 and transforming growth factor-β (TGF-β) were significantly higher in the combined group compared with those in the control group (P<0.001). Furthermore, the serum concentration levels of IL-2 and interferon-γ (IFN-γ) were significantly lower (P<0.001) and the concentration of IL-10 was significantly higher (P<0.05) in the combined group compared with those in the control group. In the mixed lymphocyte reaction, T-cell proliferation was found to be significantly lower in the combined treatment group than that in the control group (P<0.001). In conclusion, treatment with CXCL9 Ab and CXCL10 Ab or FTY720 reduced the graft infiltration of inflammatory cells, inhibited T-cell proliferation and prolonged graft survival. The combined treatment regimen of CXCL9 Ab, CXCL10 Ab and FTY720 was found to significantly reduce the infiltration of inflammatory cells in the graft and prolong graft survival.

Myocardial tissue characterisation by Cardiovascular Magnetic Resonance diagnoses and tracks recovery after cardiac transplant rejection

Introduction: Routine surveillance endomyocardial biopsies (EMBx) are associated with serious complications. Cardiovascular magnetic resonance (CMR) accurately and non-invasively diagnoses myocarditis. This study aimed to determine whether CMR is able to diagnose acute rejection in cardiac transplant recipients using a novel T2-mapping sequence. Methods: Patients underwent CMR within 24 hours of their surveillance or clinically-indicated EMBx starting from six weeks after transplantation. The T2 value was measured using a navigated black-blood turbo spin echo sequence in a single mid-short-axis slice at 1.5T (Philips Medical Systems, Best, Netherlands). Results: Thirty-six studies were performed. Using the ISHLT grading system, 12 biopsies were grade 0 (group 0), 13 grade 1R (group 1), 5 grade 3R or antibody mediated rejection (group 3). Four biopsies demonstrated no histological evidence of rejection; however, these patients were treated for acute rejection based on a decline in ejection fraction or strong clinical suspicion (group 4). Two grade 2R rejections were not included in the analysis because n=2 was too small for meaningful statistical analysis. T2 values were significantly different across groups (P<0.001; ANOVA [table]) driven by a difference between recipients with grade 3R rejection (74.8 +/-1.6; mean+/- SEM) and both grades 0 (57.2+/-1.2; P <0.05) and 1R (56.9+/-2.1; P <0.05). There was no significant difference between groups 0 and 1R (57.2+/-1.2 vs 56.9+/-2.1 (P &gt0.05)). Recipients in group 4 had elevated T2 values despite no histological evidence of cardiac rejection. Conclusion: Myocardial tissue characterisation by CMR holds promise for the detection of acute cardiac transplant rejection and may reduce the dependency on routine surveillance EMBx after cardiac transplantation.

Clinical Characteristics and Long Term Outcomes in Septuagenarians Undergoing Cardiac Transplantation

was the primary indication for device placement (n59), followed by chronic ischemic cardiomyopathy (n53) and cardiac transplant rejection (n51). The average duration of Impella support was 1167.5 days. Within 24 hours of device placement, patients had an increase in cardiac output to 5.5L/min61.4 vs 4.4L/min61.3 (p50.005), which was associated with an improvement in GFR from 45.0613.5 to 52.0614.5 (p50.01), pulmonary artery pressures 41 613.0 to 3167.0 (p50.01), right atrial pressures 11 64 to 1066 (p50.04) and pulmonary capillary wedge pressure 326 12.0 to 2065.0 (p50.03). In 84% of cases (n511), the Impella provided adequate left ventricular support, with patients either successfully weaned off support completely (n54), or receiving permanent LVADs (n55) or cardiac transplant (n52). Only 16% of patients (n52) died while actively on the Impella .The 30 day mortality was 23% (n53), while overall mortality at 90 days stood at 54% (n57). The causes of mortality included device malfunction, fatal arrhythmia 24 hours after Impella removal and withdrawal of care in 1 patient each and multi-organ failure in 4 patients who were transitioned to permanent LVAD’s. Conclusions: The Impella 5.0 has been shown to be a safe and efficacious device for use in patients with cardiogenic shock. In our high risk population, the device was easily and quickly inserted and demonstrated consistent hemodynamic augmentation. It also established itself as a good supportive modality in our acutely ill patients as well. Though our overall results in terms of mortality have not been very encouraging, the Impella was indeed successful in bridging patients to either, a permanent LVAD, transplant or in some cases ventricular recovery as well. Therefore in these high risk patients with profound cardiogenic shock, this is indeed a suitable treatment strategy.

Does Etiology of Heart Failure Predict Orthostatic Hypotension in Patents with Left Ventricular Assist Device?

was the primary indication for device placement (n59), followed by chronic ischemic cardiomyopathy (n53) and cardiac transplant rejection (n51). The average duration of Impella support was 1167.5 days. Within 24 hours of device placement, patients had an increase in cardiac output to 5.5L/min61.4 vs 4.4L/min61.3 (p50.005), which was associated with an improvement in GFR from 45.0613.5 to 52.0614.5 (p50.01), pulmonary artery pressures 41 613.0 to 3167.0 (p50.01), right atrial pressures 11 64 to 1066 (p50.04) and pulmonary capillary wedge pressure 326 12.0 to 2065.0 (p50.03). In 84% of cases (n511), the Impella provided adequate left ventricular support, with patients either successfully weaned off support completely (n54), or receiving permanent LVADs (n55) or cardiac transplant (n52). Only 16% of patients (n52) died while actively on the Impella .The 30 day mortality was 23% (n53), while overall mortality at 90 days stood at 54% (n57). The causes of mortality included device malfunction, fatal arrhythmia 24 hours after Impella removal and withdrawal of care in 1 patient each and multi-organ failure in 4 patients who were transitioned to permanent LVAD’s. Conclusions: The Impella 5.0 has been shown to be a safe and efficacious device for use in patients with cardiogenic shock. In our high risk population, the device was easily and quickly inserted and demonstrated consistent hemodynamic augmentation. It also established itself as a good supportive modality in our acutely ill patients as well. Though our overall results in terms of mortality have not been very encouraging, the Impella was indeed successful in bridging patients to either, a permanent LVAD, transplant or in some cases ventricular recovery as well. Therefore in these high risk patients with profound cardiogenic shock, this is indeed a suitable treatment strategy.

Upregulation of α-enolase in acute rejection of cardiac transplant in rat model: implications for the secretion of interleukin-17.

Acute allograft rejection remains a major problem in solid organ transplantation. The enzyme α-enolase has been shown to induce an immune response in cardiac transplantation. In this study, we investigated the role of α-enolase in acute allograft rejection in a rat model of heart transplantation. Hearts from either (WF: RT1(u) ) or (Lew: RT1(1) ) rats were transplanted into (Lew: RT1(1) ) rats. No rejection occurred in the isograft group, for which the median survival time was >168 days, whereas the median survival time of the allograft group was significantly less at 10 ± 2.1 days (n = 8 per group, p < 0.001). Increased inflammation was observed in allografts, including increased α-enolase expression and increased numbers of infiltrating CD4(+) T cells (p < 0.05). By immunohistochemical staining, we confirmed that α-enolase was expressed not only in myocardial cells but also in the infiltrating lymphocytes. However, on the fifth day after transplantation, α-enolase expression was no longer observed in the lymphocytes (n = 3, p < 0.001). In contrast, no lymphocytes were found in isografts after transplantation (n = 3, p < 0.001). α-enolase expression was increased in lymphocytes, which are implicated in the acute rejection of cardiac transplants. Intragraft α-enolase inhibition may be useful as an adjuvant therapy to systemic immunosuppression in heart transplantation.

Proteomics Identify Haptoglobin as a Novel Enhancer of Cardiac Transplant Rejection.

Proteomics Identify Haptoglobin as a Novel Enhancer of Cardiac Transplant Rejection.

(762) - Efficacy and Safety of Basiliximab as Curative Treatment of Persistent or Complicated Acute Rejection in Cardiac Transplantation

Basiliximab ( Simulect ) is a monoclonal antibody specifically directed against the alpha chain ( CD25 ) of the interleukin 2 receptor. It inhibits the activation of T lymphocytes that play a major role in the mechanism of acute rejection. It is indicated for the prevention of acute rejection in de novo allogeneic renal transplantation in adults and children and is commonly used as induction therapy in solid organ transplantation. We report a retrospective analysis of the efficacy and safety of basiliximab administered as curative treatment of acute rejection in heart transplantation.

The Use of Superparamagnetic Iron Oxide Nanoparticles to Assess Cardiac Inflammation

Superparamagnetic iron oxide-based contrast agents enhance and complement in vivo magnetic resonance imaging (MRI) by shortening T2 and T2* relaxation times. They are able to highlight areas of cellular inflammation, being detected and engulfed by cells of the reticuloendothelial system, and can be targeted to specific cellular processes or subtypes using antibody or ligand labeling. These agents have been used preclinically for the assessment of cardiac transplant rejection, cardiomyocyte apoptosis, myocardial infarction, myocarditis, and stem and endothelial cell imaging, with clinical applications now emerging. We here review recent studies using iron oxide particles to image cardiac inflammation, and highlight the potential of these agents for future clinical and research applications.

Mapping stain distribution in pathology slides using whole slide imaging

Background: Whole slide imaging (WSI) offers a novel approach to digitize and review pathology slides, but the voluminous data generated by this technology demand new computational methods for image analysis. Materials and Methods: In this study, we report a method that recognizes stains in WSI data and uses kernel density estimator to calculate the stain density across the digitized pathology slides. The validation study was conducted using a rat model of acute cardiac allograft rejection and another rat model of heart ischemia/reperfusion injury. Immunohistochemistry (IHC) was conducted to label ED1+ macrophages in the tissue sections and the stained slides were digitized by a whole slide scanner. The whole slide images were tessellated to enable parallel processing. Pixel-wise stain classification was conducted to classify the IHC stains from those of the background and the density distribution of the identified IHC stains was then calculated by the kernel density estimator. Results: The regression analysis showed a correlation coefficient of 0.8961 between the number of IHC stains counted by our stain recognition algorithm and that by the manual counting, suggesting that our stain recognition algorithm was in good agreement with the manual counting. The density distribution of the IHC stains showed a consistent pattern with those of the cellular magnetic resonance (MR) images that detected macrophages labeled by ultrasmall superparamagnetic iron-oxide or micron-sized iron-oxide particles. Conclusions: Our method provides a new imaging modality to facilitate clinical diagnosis. It also provides a way to validate/correlate cellular MRI data used for tracking immune-cell infiltration in cardiac transplant rejection and cardiac ischemic injury.