Langerhans Cells, Inflammation Markers and Human Papillomavirus Infections in Benign and Malignant Epithelial Tumors from Transplant Recipients

Organ transplant recipients frequently develop warts which progress toward premalignant or malignant lesions after a rather long grafting period. The local immune responses of such lesions (warts, condyloma acuminata, actinic keratoses, Bowen, basal and squamous cell carcinomas) was studied in 32 frozen skin specimens taken from 15 male transplant recipients and compared to similar lesions from the normal population. We studied the expression of T cell subsets, Langerhans cell phenotype, HLA class 1 (beta 2-microglobulin), HLA class 2 (DR antigen), and intercellular adhesion molecule 1 (ICAM 1). The presence of HPV infection was also considered, using in situ hybridization with biotinylated probes in order to examine the correlation with immunological markers. In the dermis, the lesions from grafted patients showed a moderate to intense inflammatory reaction of HLA-DR-positive cells. Most of these cells were CD4+ and CD8+ without any predominance of a single T cell subset. In the epidermis, most lesions were characterized by a reduced number of CD1-positive cells; this was concomitant with a decrease or a loss of beta 2-microglobulin expression by epithelial cells. HLA-DR antigen was not expressed by keratinocytes or tumoral cells in any specimen; ICAM 1 antigen was observed in a few cases. The expression of these markers was similarly modified with or without the presence of HPV DNA. Conversely, most lesions from non-immunocompromised patients, except warts, showed intense inflammatory reactions, with a predominance of CD4-positive cells and large foci of ICAM 1-positive cells. Expression of activation markers by keratinocytes occurred mainly in condylomas and squamous cell carcinomas. In the normal population, HPV infection was only detected in papilloma lesions. These data indicate, in lesions from grafted patients, a lack of effective immune response with partial inhibition of activation markers expressed by keratinocytes. It is conceivable that immunosuppressive treatment with solar exposure may also be responsible for the local immune deficiency and thus for the conversion of benign warts toward malignant lesions in grafted patients.

An animal model of endocardial fibroelastosis

BACKGROUND

Hypoplastic left heart syndrome (HLHS) is one of the most common severe congenital cardiac anomalies, characterized by a marked hypoplasia of left-sided structures of the heart, which is commonly accompanied by a thick layer of fibroelastic tissue, termed endocardial fibroelastosis (EFE). Because human EFE develops only in fetal or neonatal hearts, and often in association with reduced blood flow, we sought to mimic these conditions by subjecting neonatal and 2-wk-old rat hearts to variations of the heterotopically transplanted heart model with either no intracavitary or normal flow and compare endocardium with human EFE tissue.

MATERIALS AND METHODS

Hearts obtained from neonatal and 2-wk-old rats were heterotopically transplanted in young adult Lewis rats in a working (loaded) or nonworking (unloaded) mode. After 2-wk survival, hearts were explanted for histologic analysis by staining for collagen, elastin, and cellular elements. These sections were compared with human EFE tissue from HLHS.

RESULTS

EFE, consisting of collagen and elastin with scarce cellular and vascular components, developed only in neonatal unloaded transplanted hearts and displayed the same histopathologic findings as EFE from patients with HLHS. Loaded hearts and 2-wk-old hearts did not show these alterations.

CONCLUSIONS

This animal model for EFE will serve as a tool to study the mechanisms of EFE formation, such as fluid forces, in HLHS in a systematic manner. A better understanding of the underlying cause of the EFE formation in HLHS will help to develop novel treatment strategies to better preserve growth of the hypoplastic left ventricle.

[The donor's heart 22 years after the orthotopic transplantation]

The orthotopic heart transplantation is an acknowledge method for the treatment of cardiomyopathies of various etiology. Specific vasculopathy of the transplanted heart is considered to be a significant problem of the long-term postoperative period and serves the reason of low 10-years survival rates (not more then 50%). The issue unites the experience of follow-up and intravital electronic microscopy of transplantated heart's biopsies from 20 patients. Previously unknown data can help the clarification of posttransplantational cardiomyopathy.

Endomyocardial biopsy for monitoring heart transplant patients: 11-years-experience at a german heart center

BACKGROUND

Heart transplantation (HTX) has become an established therapy for patients with end-stage heart failure. Endomyocardial biopsy (EMB) still represents the gold standard for routine surveillance of heart transplant rejection. The objective of this article is to report our experience regarding the use of EMB in monitoring heart transplant recipients.

METHODS

We evaluated retrospectively all patients who underwent orthotopic HTX between 2000 and 2011 at our hospital. From all patients, we created a follow-up, determined the number of EMB events and described the complications associated with this procedure.

RESULTS

HTX was performed in 142 cases at our center in the last 11 years (1.3% of the total of 10693 cardiac surgical operations in that period). Further 9 patients visited our department for monitoring after HTX performed at an external center (total: 151). For all patients, a total of 1896 EMB events have been recorded. The majority of biopsies were performed through the right internal jugular vein. The overall complication rate was 1% (n=19).

CONCLUSIONS

The histological examination of right ventricular EMB still represents the gold standard of care for cardiac allograft rejection monitoring. EMB is an invasive, but safe and dedicated diagnostic procedure. However, the usefulness of recent non-invasive diagnostic approaches as an adjunct tool in monitoring for rejection remains to be further analyzed.

Low-dose unfractionated heparin administration during intravascular ultrasound studies is safe even shortly after endomyocardial biopsy in cardiac transplant patients

BACKGROUND

Full therapeutic heparin doses ranging from 5000-10,000 units or weight based (70-100 units/kg) have been recommended during percutaneous coronary interventions. However, there are currently no data available in regards to the appropriate dosing of unfractionated heparin during intravascular ultrasound (IVUS) studies without therapeutic coronary interventions. The goal of this study was to evaluate the safety of low dose unfractionated heparin during IVUS studies, shortly after endomyocardial biopsy in cardiac transplant patients.

METHODS

At the University of Arizona Medical Center, transplant patients routinely undergo diagnostic IVUS studies for the detection of early cardiac allograft vasculopathy (CAV) shortly after endomyocardial biopsy. A low-dose heparin (2000 to 3000 Units) is given before coronary wire and IVUS catheter advancement without checking activated clotting time. We evaluated the occurrence of any thromboembolic event or any other adverse outcomes in this population.

RESULTS

A total of 108 cardiac transplant patients, who had underwent routine IVUS studies between 2004-2008 were identified retrospectively. The average heparin dose used was 2528 ± 501 units. The left anterior descending artery was studied in 93% of cases. There was no thromboembolic event. Only one catheter-induced coronary dissection occurred treated with percutaneous coronary intervention. An endomyocardial biopsy was performed 10-15 minutes before the administration of low-dose heparin. There were no other major adverse cardiac events in this population during the procedure.

CONCLUSION

This is the first study showing the safety of low-dose heparin use during diagnostic IVUS studies in cardiac transplant patients, even shortly after endomyocardial biopsy.

Kinetics of T-lymphocyte subsets and posttransplant opportunistic infections in heart and kidney transplant recipients

BACKGROUND

The potential use of T-lymphocyte measurements as infection risk markers after solid organ transplant has not been fully investigated. We analyzed the kinetics of T-lymphocyte subsets within the first 8 months posttransplant and their correlation with opportunistic infections (OIs) in solid organ transplant recipients.

METHODS

Serial measurement of CD4 and CD8 T cells was performed retrospectively in 48 heart transplant recipients (HTR) and 42 kidney transplant recipients (KTR). Generalized estimating equation models were used to analyze longitudinal data separately for HTR and KTR.

RESULTS

An initial CD4 T-cell drop (at months 1 and 2, in HTR and KTR, respectively) coincided with the peak of OIs. HTR with a low nadir CD4 T-cell count (≤ 200/μL) showed poor CD4 T-cell recovery (175 ± 277 cells/μL at baseline vs 242 ± 99 cells/μL at month 8) and their CD8 T cells increased from 153 ± 194 cells/μL at baseline to 601 ± 399 cells/μL at month 8. KTR with a low nadir CD4 T-cell count (≤ 200/μL) showed a modest CD4 T-cell recovery (138 ± 46 cells/μL at baseline vs. 440 ± 448 cells/μL at month 8), and their CD8 T cells increased from 90 ± 41 cells/μL at baseline to 450 ± 242 cells/μL at month 8. HTR developing OIs had lower CD4 (P<0.001) and CD8 T cells (P=0.001) than those without infections, whereas in KTR the risk for OIs seemed restricted to patients with low CD8 T cells. HTR with OIs had a low CD4/CD8 T-cell ratio, whereas KTR had a high CD4/CD8 T-cell ratio.

CONCLUSIONS

Determination of T-lymphocyte subsets is a simple and effective parameter to identify patients at risk of developing OIs.

Does the method of heart transplantation affect left ventricular filling?

BACKGROUND

For over 40 years now orthotopic heart transplantation (OHT) has been the treatment of choice in patients with advanced heart failure. For many years patients undergoing OHT have been treated with the classical approach involving anastomosis of the donor atria with the recipient atria resulting in a heart in which the atria are enlarged. An alternative method for OHT is the bicaval anastomosis technique, which involves connecting both of the donor's venae cavae with the recipient's venae cavae.

AIM

To assess left ventricular (LV) filling in patients undergoing OHT using the classical (biatrial) versus bicaval approach.

METHODS

We analysed 60 patients who had undergone OHT between 1 and 36 months before. Myocardial biopsy at echocardiography revealed grade 0 or 1A rejection in all the patients. All the patients were also in NYHA functional class I. The patients were divided in two groups: patients who had undergone biatrial anastomosis (Group 1, n = 40) and patients who had undergone bicaval OHT (Group 2, n = 20). In order to render the results independent of pre-OHT blood pressure values in the pulmonary circulation we assessed the values of right ventricular systolic pressure (RVSP), mean pulmonary artery pressure (PAP) and transpulmonary gradient (TPG) in all the patients before OHT. We assessed the following echocardiographic parameters: peak early filling velocity (E-wave), peak atrial filling velocity (A-wave), E-wave deceleration time, early diastolic mitral valve ring motion velocity (E'), E/E', isovolumetric relaxation time of the LV, duration of the A-wave, right atrial area and left atrial area, LV mass, LV mass index, LV end-diastolic and end-systolic dimension, and the severity of tricuspid regurgitation (TR).

RESULTS

The values of RVSP, PAP and TPG in the study groups before OHT did not differ significantly. The values of E (86.5 ± 12.5 vs. 67.3 ± 8.5; p < 0.001), E' (11.9 ± 1.1 vs. 10.9 ± 0.9; p = 0.003) and E/E' (7.4 ± 1.5 vs. 6.1 ± 0.85; p = 0.006) differed between the groups and were significantly higher in the group undergoing surgery using the biatrial approach. The duration of the A-wave was significantly longer in the group undergoing surgery using the bicaval approach (129.0 ± 5.1 vs. 136.7 ± 10.0; p = 0.001). There were no significant differences in the other parameters of LV filling. Right atrial area was significantly lower in the group undergoing surgery using the bicaval approach (19.2 ± 3.0 vs. 14.0 ± 2.0; p < 0.001). LV size, LV mass and LV mass index did not differ significantly between the groups. The lack of TR was more commonly observed in the group undergoing surgery using the bicaval approach at the limit of p = 0.05. Pacemaker implantation was required in 12 (30%) patients from the group undergoing surgery using the classical method and 2 (10%) patients from the group undergoing OHT using the bicaval approach (p = 0.04).

CONCLUSIONS

Certain echocardiographic parameters suggest a better LV filling in patients undergoing OHT using the bicaval approach. Preservation of the right atrial geometry in patients undergoing OHT using the bicaval approach plays an important role in LV filling.

Role of the Fc region in CD70-specific antibody effects on cardiac transplant survival

BACKGROUND

The role of the CD70-specific antibody and the mechanisms by which it extends transplant survival are not known.

METHODS

Fully major histocompatibility complex-mismatched heterotopic heart transplantation (BALB/c to C57BL/6) was performed. Treated mice received intraperitoneal injections of wild-type (WT) CD70-specific antibody (FR70) or IgG1 or IgG2a chimeric antibodies on days 0, 2, 4, and 6 posttransplantation.

RESULTS

WT FR70 antibody significantly extended heart transplant survival to 19 days compared with untreated mice (median survival time [MST]=10 days). Graft survival using the nondepleting IgG1 antibody was significantly shorter (MST=14 days), whereas the survival using depleting IgG2a antibody (MST=18) was similar to that using WT FR70. The FR70 and IgG2a antibodies demonstrated a greater efficiency of fixing mouse complement over the IgG1 variant in vitro. CD4 and CD8 T-cell graft infiltration was reduced with treatment; however, this was most pronounced with WT FR70 and IgG2a antibody therapy compared with the IgG1 chimeric variant. Circulating donor-specific IgG alloantibodies were initially reduced with WT FR70 treatment (day 8 posttransplantation) but increased at days 15 and 20 posttransplantation to the level detected in untreated controls.

CONCLUSION

We conclude that WT (FR70) and the IgG2a depleting variant of CD70-specific antibody reduce graft infiltrating CD4 and CD8 T cells, transiently reduce serum alloantibody levels, and extend graft survival. In contrast, the nondepleting IgG1 variant of this antibody showed lower efficacy. These data suggest that a depleting mechanism of action and not merely costimulation blockade plays a substantial role in the therapeutic effects of CD70-specific antibody.

Comparison of 2 heterotopic heart transplant techniques in rats: cervical and abdominal heart

OBJECTIVES

Heterotopic heart transplant in rats has been accepted as the most commonly used animal model to investigate the mechanisms of transplant immunology. Many ingenious approaches to this model have been reported. We sought to improve this model and compare survival rates and histologic features of acute rejection in cervical and abdominal heart transplants.

MATERIALS AND METHODS

Rats were divided into cervical and abdominal groups. Microsurgical techniques were introduced for vascular anastomoses. In the abdominal heart transplant group, the donor's thoracic aorta was anastomosed end-to-side to the recipient's infrarenal abdominal aorta, and the donor's pulmonary artery was anastomosed to the recipient's inferior vena cava. In the cervical heart transplant group, the donor's thoracic aorta was anastomosed to the recipient's common carotid artery, and the donor's pulmonary artery was anastomosed to the recipient's external jugular vein. Survival time of the 2 models was followed and pathology was examined. Histologic features of allogeneic rejection also were compared in the cervical and abdominal heart transplant groups.

RESULTS

The mean time to recover the donor's hearts was 7.4 ± 2.2 minutes in the cervical group and 7.2 ± 1.8 minutes in the abdominal group. In the cervical and abdominal heart transplant models, the mean recipient's operative time was 23.2 ± 2.6 minutes and 21.6 ± 2.8 minutes. Graft survival was 98% and 100% in the cervical and abdominal heart transplant groups. There was no significant difference in graft survival between the 2 methods. Heart allografts rejected at 5.7 and 6.2 days in the cervical and abdominal transplant groups. There was no difference in the histologic features of acute allogenic rejection in cervical and abdominal heart transplant.

CONCLUSIONS

Both cervical and abdominal heart transplants can achieve a high rate of success. The histologic features of acute allogeneic rejection in the models are comparable.

[The first experience with heart transplantation in the Federal Center of the Heart, Blood and Endocrinology named after V. A. Almazov]

At the present time heart transplantation is considered to be the operation of choice in treatment of patients with terminal stage of chronic heart failure. Results of the first 5 heart transplantations made in the Federal Center of the heart, blood and endocrinology named after V. A. Almazov are assessed. There were no perioperational lethality and complications at the hospital stage. An analysis of the long-term results has shown effectiveness of heart transplantations in treatment of severe heart pathology.

Neutrophil immunosurveillance for heart transplant rejection: a prospective study

Immunologic surveillance for rejection detection in human heart transplantation offers many potential advantages. To date, investigative efforts have focused primarily on the acquired immune system, particularly the lymphocyte. Little attention has been given to aspects of innate immune function. We have previously reported that perioperative neutrophil adhesion molecule expression is associated with early rejection episodes after human cardiac transplantation. Herein we have investigated the utility of neutrophil immunosurveillance in human heart transplant recipients at later time points. We recruited patients more than 3 months after transplantation. Neutrophil assessment was performed simultaneously with an endomyocardial biopsy that showed rejection. No significant relationship was seen between neutrophil maturity (P = .622; n = 34), adhesion marker expression (P = .567; n = 34), respiratory burst (P = .604; n = 34), or apoptosis rates (P = .662; n = 34) and contemporary rejection status at >3 months after transplantation. However, interesting relationships were noted between neutrophil adhesion markers at this late stage and historical rejection status. Higher levels of the adhesion protein CD11b observed at this late stage were significantly associated with a history of higher rejection grades in the first postoperative biopsy (Spearman rank coefficient 0.359; R = 0.304; P = .005; n = 62). Other aspects of neutrophil function and persistence were not significantly associated with rejection history. This finding, combined with the previously reported findings, supports a role for an individual phenotype in neutrophil function in early rejection episodes after transplantation.

Increased Th17 rather than Th1 alloimmune response is associated with cardiac allograft vasculopathy after hypothermic preservation in the rat

BACKGROUND

Preservation injury decreases patient survival and promotes the development of cardiac allograft vasculopathy. We investigated the sequential effects of hypothermic preservation on ischemia-reperfusion injury (IRI), subsequent innate immune activation, and adaptive immune response in rat cardiac allografts.

METHODS

Allografts were transplanted from fully major histocompatibility complex-mismatched Dark Agouti to Wistar Furth rats without pre-operative hypothermia or after 4 hours of hypothermic preservation. Recipients received cyclosporine A immunosuppression. The allografts were recovered at 6 hours (n = 6, 7), 24 hours (n = 6), 10 days (n = 5), and 8 weeks (n = 5). Immunohistochemical, histologic, and reverse-transcription polymerase chain reaction analysis was performed.

RESULTS

In IRI, significantly increased messenger RNA (mRNA) levels for Toll-like receptor 4, hyaluronan synthases (HAS)1-2 (p = 0.03), high-mobility group box 1 (p = 0.05), CD80/83 (p = 0.01, p = 0.048), and the cytokines tumor necrosis factor-alpha (p = 0.004), interferon-gamma (p = 0.012), and interleukin (IL)-6 (p = 0.019) were seen in allografts subjected to hypothermic preservation. During established alloimmune response, allografts subjected to hypothermic preservation expressed prominent infiltration of CD4+ T cells (p = 0.043) and dendritic cells (p = 0.029) and significantly up-regulated mRNA levels of CD80 (p = 0.036), chemokine (C-C motif) ligand 21 (p = 0.008), C-C chemokine receptor type 7 (p = 0.003), vascular endothelial growth factor-C (p = 0.016), and vascular endothelial growth factor receptor-3 (p = 0.02). These allografts also showed prominent mRNA upregulation of Foxp3 (p = 0.014), IL-17 (p = 0.038), and IL-23 (p = 0.043). Preservation significantly increased the incidence and intensity of allograft arteriosclerosis (p < 0.05) and cardiac fibrosis (p = 0.003) at 8 weeks.

CONCLUSION

Our results demonstrate that preservation injury induced a cascade leading to an innate immune response that modulated the adaptive immune response towards Th17 rather than Th1 T-cell response in rat cardiac allografts and ultimately enhanced cardiac fibrosis and arterial occlusion. Our results also suggest that this immune response was not regulated by the calcineurin inhibitor cyclosporine A.

Cardiac allograft rejection: examination of the expression and function of the decoy chemokine receptor D6

BACKGROUND

Inflammatory cell recruitment during allograft rejection is driven by a group of inflammatory cytokines termed chemokines. Chemokines are presented on the surface of the vascular endothelium where they ligate specific receptors expressed on the surface of leukocytes. Recently, a group of nonsignaling chemokine receptors have been described. These bind and internalize chemokines but do not drive leukocyte migration. It is believed that these compete with classical signaling receptors to modulate inflammation.

METHODS

This study describes the first examination of the human decoy chemokine receptor D6 during rejection; D6 binds at least 12 potent proinflammatory chemokines. The expression of D6 by graft infiltrating leukocytes was examined in cardiac allografts by confocal microscopy on biopsy sections (n=19). Cytokine regulation of D6 was examined in vitro, and a chemokine scavenging assay was performed using the prototypical transplant-associated chemokine CCL5/RANTES.

RESULTS

D6 expression was found to be higher in the biopsies taken from more severe cardiac allograft rejection (P<0.01) and was predominantly localized to graft infiltrating CD45(+)CD68(+) leukocytes. In vitro studies demonstrated that the transforming growth factor-beta strongly increased the expression of D6 by monocytes, which significantly enhanced D6-mediated chemokine scavenging (by 85%, P<0.05).

CONCLUSIONS

We present the first examination of the biology of D6 during rejection and identify a transplant-associated cytokine that is able to regulate its expression. These data suggest an exciting new mechanism for the antiinflammatory actions of transforming growth factor-beta. Understanding the expression patterns of D6 may provide important insight into the regulation and control of inflammatory cell recruitment during allograft rejection.

Pivotal karyometric measurements in different types of cardiomyopathic morphology: study of hearts explanted from transplant recipients

BACKGROUND

Morphometric studies based on the measurement of cardiocyte nuclei have focused on progressive hypertrophy rather than shape, which is a deciding factor for the diagnosis of hypertrophy in myocardial diseases. The aim of this research was to demonstrate how the digital morphology of cardiocyte nuclei change correlated with the type of myocardial pathology.

MATERIALS AND METHODS

The study groups encompassed 7 hearts with dilated cardiomyopathy (DCM) and 8 hearts with ischemic heart disease (IHD) which were explanted. A comparative group consisting of myocardial hypertrophy was contrasted with a control group of donor heart fragments. Cardiocyte nuclei were evaluated morphometrically on histologic slides. We calculated the nuclear area, length, breadth, perimeter, roundness, elongation, fullness factors, and nuclear chromatin mean gray level. The results were subjected to discriminant analysis.

RESULTS

All karyometric measurements analyzed by backward discriminant analysis showed only 2 powerful factors: nuclear breadth and chromatin mean gray level. The Mahalanobis distance showed the proximity of control and hypertrophy groups, whereas differences between IHD and DCM were nonsignificant.

CONCLUSION

The lack of karyometric differences between IHD and DCM suggested a common morphologic response for long-lasting progressive injury. The main morphologic differences were dependent on nuclear chromatin activity/stainability and nuclear breadth, suggesting darker and thinned nuclei in normal and adaptative stages and irregular brighter nuclei in cardiomyopathies.

Two-stage total cardioaortic replacement for end-stage heart and aortic disease in Marfan syndrome: case report and review of the literature

A 24-year-old man with Marfan syndrome underwent mitral valve repair for prolapse at age 13. He sustained an acute type A aortic dissection at age 20 and underwent aortic root/ascending aortic replacement with a mechanical valved conduit. He initially did well after the latter procedure, but end-stage heart disease developed 4 years later, apparently secondary to primary cardiomyopathy. Pre-transplant evaluation revealed residual chronic dissection with aneurysmal dilatation of the distal ascending aorta, transverse arch, and descending thoracic aorta. He underwent combined orthotopic heart transplantation (OHT) and total arch replacement (stage I elephant trunk procedure). Subsequently, he underwent extent II thoracoabdominal aneurysm repair, leaving no residual aortic disease. The 2 procedures resulted in total cardioaortic replacement, thus definitively managing his cardiomyopathy and aortic disease resulting from Marfan syndrome. The operative strategies employed represent a novel approach in this clinical setting. This report emphasizes that patients with this disease should not be denied potentially life-saving OHT on the basis of concomitant aortic disease, but rather should be treated in centers offering expertise in both areas of surgical therapy.

Organ recipients suffering from undifferentiated neuroendocrine small-cell carcinoma of donor origin: a case report

BACKGROUND

Transmission of donor-derived cancer by organ transplantation is rare, but the risk has been increasing due to the aging donor pool. Undifferentiated neuroendocrine small-cell carcinoma is an aggressive tumor with the tendency to spread. Herein we have demonstrated different approaches to treat organ recipients with transmitted tumors.

METHODS AND RESULTS

Grafts were retrieved from a decreased donor without any history of previous diseases. Autopsy was not performed after donation. The recipient of the liver graft presented with suspected nodules on routine abdominal ultrasound. After computed tomography (CT) scan, biopsy confirmed the diagnosis of a small-cell carcinoma. Donor origin was unequivocally identified by DNA fingerprinting. Despite chemotherapy the patient died 7 months after orthotopic liver transplantation (OLT). All involved transplantation centers were informed immediately following diagnosis. The male kidney recipient underwent detailed diagnostic work-up to exclude tumor transmission. One year after transplantation, liver metastases caused by a histologically proven small-cell carcinoma from the same donor were apparent. Chemotherapy was immediately started and the graft was removed. Despite continued treatment the tumor progressed and the patient died after repeated intestinal complications. The pathological examination of the explanted second kidney graft did not show any tumor infiltration.

CONCLUSION

Therapeutic regimens in recipients suffering from donor-derived carcinoma differ depending on the transplanted organ. Graft removal of non-life-sustaining organs and discontinuation of immunosuppressive medication should result in complete tumor rejection. Minimizing the risk of tumor transmission, a CT scan might be advisable in donors of more advanced age.

Differences in antiapoptotic, proliferative activities and morphometry in dilated and ischemic cardiomyopathy: study of hearts explanted from transplant recipients

BACKGROUND

Antiapoptotic as well as replacement and proliferative mechanisms take place in the myocardium in dilated cardiomyopathy (DCM) and ischemic heart disease (IHD). We sought to estimate antiapoptotic, proliferative and replacement activities in cardiomyopathies.

MATERIALS

The study groups included seven hearts with DCM and eight with IHD, which had been explanted at the time of transplantation. The comparator group consisted of cases of myocardial hypertrophy and the control group, donor fragments.

METHODS

Antiapoptotic and proliferative responses were determined immunohistochemically as Bcl-2 and Ki67 expression by semiquantitative assessment of the intensity of staining. We also measured and statistically analyzed the integrative morphometric measurements of the fraction of fibrosis area, the nucleosarcoplasmic ratio, and cardiocyte diameter.

RESULTS

No Bcl-2 expression was observed in the controls. The strongest reaction was seen in the DCM group, then in the IHD, and in the comparator group of myocardial hypertrophy. Proliferative activity was seen only in endocardial and interstitial fibroblasts in DCM and IHD cases. The cardiocyte diameter showed no statistical association between myocardial hypertrophy and IHD, or IHD and DCM, whereas the nucleosarcoplasmic ratios were significantly different from control groups for all comparisons. Myocardial fibrosis showed the highest values in DCM and IHD. Discriminant analysis showed the value of interstitial fibrosis and cardiocyte diameter to categorize the analyzed groups.

CONCLUSIONS

Antiapoptotic Bcl-2 activity seemed to play an important role in cardiocyte preservation, while proliferative activity was resticted to interstitial connective tissue cells as a replacement process. Myocardial Bcl-2 expression, the extent of myocardial fibrosis, and cardiocyte diameter may serve as additional diagnostic tools to differentiate cardiomyopathies.

What else distinguishes cellular rejection grade 1A from 0? Annexin V and BCL in elective biopsies received from heart transplant recipients

BACKGROUND

Despite morphologic differences of lymphocytes aggregation between nonrejection (0 on the International Society for Heart and Lung Transplantation [ISHLT] scale) and moderate focal cellular rejection (1a, ISHLT), genetic and clinical differences have not been shown in Cardiac Allograft Rejection Gene Observation (CARGO) studies. Therefore, we sought to compare the expression of selected antigens associated with apoptosis in heart transplant recipients in the context of grade 0 versus grade 1a cellular rejection episodes. We assessed the expression of annexin V, a nonspecific apoptosis marker, Bcl-2 as opposed to antiapoptotic activity of Bcl-xL and Bcl-xL/S.

MATERIALS AND METHODS

We retrospectively examined 17 heart transplant patients (2 women and 15 men) of overall mean age of 46.2 +/- 13.9 years and body mass index of 25.7 +/- 3.2. Ten biopsies showed rejection grade 0 and the other 10, grade 1a on the ISHLT scale, comprising groups A and B, respectively. Endomyocardial biopsy specimens were processed using routine immunohistochemical methods. The expression of apoptotic molecules was assessed according to the IHC method: 0, the lack of expression; 1, trace; 2, distinct; and 3, strong. A correlation was analyzed between particular molecular expressions.

RESULTS

We observed a significant increase in Bcl-2 expression associated with rejection. The expression of other antigens did not show a significant tendency. No correlation was noted among group A, whereas in group B those were significant strong and negative correlations with Bcl-2 and Bcl-xL/S.

CONCLUSION

Bcl-2 expression corresponded to the morphologic progression of graft rejection as opposed to Bcl-xL/S activity.

Myocardial and peripheral lymphocytic transcriptomic dissociation of beta-adrenoceptors and G protein-coupled receptor kinases in heart transplantation

BACKGROUND

The genetic expression of adrenergic receptors plays an important pathophysiologic role in heart failure. G protein-coupled receptor kinases (GRKs) desensitize the beta-receptor to catecholaminergic stimulation. It has been suggested that their mRNA expression in peripheral lymphocytes could mirror the changes in their myocardial expression in the failing heart, but this relationship between the myocyte and lymphocyte has not been studied in heart transplantation (HT). The objective of this study was to analyze adrenergic receptor and GRK mRNA expression in myocardium and lymphocytes and their correlation.

METHODS

Twenty-three HT patients without evidence of acute rejection or echocardiographic dysfunction were assessed. Myocardial biopsy samples and peripheral blood lymphocytes were obtained, and alpha(1)- and beta-adrenoceptor subtype and GRK subtype mRNA was analyzed using reverse transcript-polymerase chain reaction (RT-PCR).

RESULTS

Mean age was 45 +/- 15 years, with a median of time since HT of 205 (351) days. In biopsies, the beta(1)/beta(2)-adrenoceptor ratio was 57%/42%, and GRK5 was the most commonly expressed, followed by GRK2. In lymphocytes, the beta(1)/beta(2) ratio was 3%/96%, whereas GRK2 mRNA expression was greater than that of other subtypes. There was no correlation between myocardial and lymphocyte parameters. There were no correlations with clinical variables, but lymphocyte beta(2) and GRK2 were increased with time since HT.

CONCLUSIONS

In the transplanted heart, there is no correlation between mRNA expression of adrenoceptors and GRKs in myocardium and peripheral lymphocytes. With time since transplant, mRNA expression of lymphocyte but not myocardial beta(2)-adrenoceptor and GRK2 increases. Therefore, this dissociation between myocardial and lymphocyte mRNA expression limits the potential use of peripheral blood samples for diagnosis of graft dysfunction.

[Consensus document on endomyocardial biopsy of the Associazione per la Patologia Cardiovascolare Italiana]

The Italian Scientific Associations of Cardiologists and Cardiovascular Pathologists have produced this consensus document on the diagnostic role of endomyocardial biopsy (EMB) in terms of techniques, analysis and reporting. The document is intended for clinical cardiologists, hemodynamic experts, electrophysiologists, surgical pathologists, and cardiac surgeons. It has three main aims: a) to collocate EMB in the context of currently available tools for diagnosis of heart diseases; b) to provide recommendations for rational implementation; c) to outline key characteristics (standards) for Italian cardiology and surgical pathology centers that perform and analyze EMB. A general lack of prospective, controlled studies addressing EMB prohibited the use of traditional evidence-based recommendations that rely on classes of available evidence. Thus, it was agreed that three key points should be taken into account: a) the specific pathology to be diagnosed (or excluded); b) the existence of any alternative, non-invasive diagnostic techniques; c) the overall consequences of reaching a definite diagnosis on patients' clinical management. Accordingly, we propose recommendations for EMB based on the following levels of diagnostic value: level 1: no alternative method exists to reach a definite diagnosis that can have obvious consequences for clinical management; level 2a: no alternative method exists to reach a definite diagnosis; however, the implications for clinical management are uncertain; level 2b: no alternative method exists to reach a definite diagnosis; however, the diagnosis would not influence clinical management; level 3: an alternative method exists to reach a definite diagnosis. The second part of the document proposes current protocols for the preparation, analysis and reporting of EMB in the context of each main pathologic entity. Particular attention is given to tissue characterization and implementation of molecular tests.

Influence of traditional cardiovascular risk factors in the recipient on the development of cardiac allograft vasculopathy after heart transplantation

BACKGROUND

Cardiac allograft vasculopathy (CAV) is the leading cause of death heart transplant (HT) recipients after the first year. We assessed the influence of cardiovascular risk factors (CVRFs) in HT recipients on the development of CAV after 1 year of follow-up.

MATERIALS AND METHODS

From 2001 to 2005, we studied 72 patients who received a HT and survived for at least 1 years. All patients underwent coronary arteriography and intravascular ultrasonography at 1 year after HT. Cardiac allograft vasculopathy was defined as intimal proliferation of 0.5 mm or more. The analyzed CVRFs were age, sex, body mass index, diabetes mellitus, hypertension, dyslipidemia, and smoking. We also considered the heart disease that was the reason for HT. The statistical tests used in the univariate analysis were the t and chi(2) tests. Logistic regression was performed with the variables obtained at univariate analysis.

RESULTS

Mean (SD) recipient age at HT was 51 (9) years. Eighty patients (90.5%) were men. Dyslipidemia was significantly associated with a greater incidence of CAV at 1 year (68.3% vs 41.9%; P = .03). Ischemia, as opposed to all other causes, was also significantly associated with CAV (69.4% vs 44.4%; P = .03). Older age, hypertension, smoking history, and high body mass index were associated with a higher incidence of CAV, albeit without statistical significance. At multivariate analysis, dyslipidemia was the most significant CVRF (P = .045) for the development of CAV.

CONCLUSIONS

Recipient dyslipidemia is a risk factor for the development of CAV in HT. The remaining traditional CVRFs are more weakly associated with CAV. After HT close monitoring of recipients with pretransplantation CVRFs is essential for early detection of CAV.

Sepiapterin decreases acute rejection and apoptosis in cardiac transplants independently of changes in nitric oxide and inducible nitric-oxide synthase dimerization

Tetrahydrobiopterin (BH(4)), a cofactor of inducible nitric-oxide synthase (iNOS), is an important post-translational regulator of NO bioactivity. We examined whether treatment of cardiac allograft recipients with sepiapterin [S-(-)-2-amino-7,8-dihydro-6-(2-hydroxy-1-oxopropyl)-4-(1H)-pteridinone], a precursor of BH(4), inhibited acute rejection and apoptosis in cardiac transplants. Heterotopic cardiac transplantation was performed in Wistar-Furth donor to Lewis recipient strain rats. Recipients were treated daily after transplantation with 10 mg/kg sepiapterin. Grafts were harvested on post-transplant day 6 for analysis of BH(4) (high-performance liquid chromatography), expression of inflammatory cytokines (reverse transcription- and real-time polymerase chain reaction), iNOS (Western blots), and NO (Griess reaction and NO analyzer). Histological rejection grade was scored, and graft function was determined by echocardiography. Apoptosis, protein nitration, and oxidative stress were determined by immunohistochemistry. Treatment of allografts with sepiapterin increased cardiac BH(4) levels by 3-fold without changing protein levels of GTP cyclohydrolase, the enzyme that regulates de novo BH(4) synthesis. Sepiapterin decreased inflammatory cell infiltrate and significantly inhibited histological rejection scores and apoptosis similar in magnitude to cyclosporine. Sepiapterin also decreased nitrative and oxidative stress. Sepiapterin caused a smaller increase in left ventricular mass versus untreated allografts but without improving fractional shortening. Sepiapterin did not alter tumor necrosis factor-alpha and interferon-gamma expression, whereas it decreased interleukin (IL)-2 expression. Sepiapterin did not change total iNOS protein or monomer levels, or plasma and tissue NO metabolites levels. It is concluded that the mechanism(s) of antirejection are due in part to decreased apoptosis, protein nitration, and oxidation of cardiomyocytes, which seems to be mediated at the immune level by limiting inflammatory cell infiltration via decreased IL-2-mediated T-lymphocyte expansion.

Asymptomatic antibody-mediated rejection after heart transplantation predicts poor outcomes

BACKGROUND

Antibody-mediated rejection (AMR) has been associated with poor outcome after heart transplantation. The diagnosis of AMR usually includes endomyocardial biopsy findings of endothelial cell swelling, intravascular macrophages, C4d+ staining, and associated left ventricular dysfunction. The significance of AMR findings in biopsy specimens of asymptomatic heart transplant patients (normal cardiac function and no symptoms of heart failure) is unclear.

METHODS

Between July 1997 and September 2001, AMR was found in the biopsy specimens of 43 patients. Patients were divided into 2 groups: asymptomatic AMR (AsAMR, n = 21) and treated AMR (TxAMR with associated left ventricular dysfunction, n = 22). For comparison, a control group of 86 contemporaneous patients, without AMR, was matched for age, gender, and time from transplant. Outcomes included 5-year actuarial survival and development of cardiac allograft vasculopathy (CAV). Patients were considered to have AMR if they had > or = 1 endomyocardial biopsy specimen positive for AMR.

RESULTS

The 5-year actuarial survival for the AsAMR (86%), TxAMR (68%), and control groups (79%) was not significantly different (p = 0.41). Five-year freedom from CAV (> or = 30% stenosis in any vessel) was AsAMR, 52%; TxAMR, 68%; and control, 79%. Individually, freedom from CAV was significantly lower in the AsAMR group compared with the control group (p = 0.02). There was no significant difference between AsAMR vs TxAMR and TxAMR vs control for CAV.

CONCLUSIONS

Despite comparable 5-year survival with controls after heart transplantation, AsAMR rejection is associated with a greater risk of CAV. Trials to treat AsAMR to alter outcome are warranted.

Host-derived smooth muscle cells accumulate in cardiac allografts: role of inflammation and monocyte chemoattractant protein 1

Transplant arteriosclerosis is characterized by inflammation and intimal thickening caused by accumulation of smooth muscle cells (SMCs) both from donor and recipient. We assessed the relationship between clinical factors and the presence of host-derived SMCs in 124 myocardial biopsies from 26 consecutive patients who received hearts from opposite-sex donors. Clinical and demographic information was obtained from the patients' medical records. Host-derived SMCs accounted for 3.35±2.3% of cells in arterioles (range, 0.08–12.51%). As shown by linear regression analysis, an increased number of SMCs was associated with rejection grade (mean, 1.41±1.03, p = 0.034) and the number of leukocytes (19.1±12.7 per 20 high-power fields, p = 0.01). The accumulation of host-derived SMCs was associated with an increased number of leukocytes in the allografts. In vitro, monocyte chemoattractant protein 1 (MCP-1) released from leukocytes was crucial for SMC migration. After heart allotransplantion, mice treated with MCP-1-specific antibodies had significantly fewer host-derived SMCs in the grafts than mice treated with isotypic antibody controls. We conclude that the number of host-derived SMCs in human cardiac allografts is associated with the rejection grade and that MCP-1 may play pivotal role in recruiting host-derived SMCs into cardiac allografts.

CD4+CD25+ T cells alloactivated ex vivo by IL-2 or IL-4 become potent alloantigen-specific inhibitors of rejection with different phenotypes, suggesting separate pathways of activation by Th1 and Th2 responses

CD4(+)CD25(+)Foxp3(+) T cells are regulatory/suppressor cells (Tregs) that include non-antigen (Ag)-specific as well as Ag-specific Tregs. How non-Ag-specific naive CD4(+)CD25(+) Treg develop into specific Tregs is unknown. Here, we generated adaptive Tregs by culture of naive CD4(+)CD25(+)Foxp3(+) T cells with allo-Ag and either interleukin-2 (IL-2) or IL-4. Within days, IL-2 enhanced interferon-gamma receptor (Ifngammar) and Il-5 mRNA and IL-4 induced a reciprocal profile with de novo IL-5Ralpha and increased IFN-gamma mRNA expression. Both IL-2- and IL-4-alloactivated CD4(+)CD25(+) Tregs within 3 to 4 days of culture had enhanced capacity to induce tolerance to specific donor but not to third-party cardiac allografts. These hosts became tolerant as allografts functioned more than 250 days, with a physiologic ratio of less than 10% CD4(+)CD25(+)Foxp3(+) T cells in the CD4(+) population. CD4(+)CD25(+) T cells from tolerant hosts given IL-2-cultured cells had increased Il-5 and Ifngammar mRNA. Those from hosts given IL-4-cultured cells had enhanced IL-5Ralpha mRNA expression and IL-5 enhanced their proliferation to donor but not third-party allo-Ag. Thus, IL-2 and IL-4 activated allo-Ag-specific Tregs with distinct phenotypes that were retained in vivo. These findings suggested that T-helper 1 (Th1) and Th2 responses activate 2 pathways of adaptive Ag-specific Tregs that mediate tolerance. We propose they be known as T-suppressor 1 (Ts1) and Ts2 cells.

Bortezomib for refractory antibody-mediated cardiac allograft rejection

This experience demonstrates that a bortezomib-based regimen provided effective therapy for late, refractory AMR in an adult heart transplant recipient and was well tolerated. This remarkably positive experience despite the refractory nature of the AMR episode argues strongly for continued evaluation of bortezomib use in this patient population.

A clinical correlation study of severity of antibody-mediated rejection and cardiovascular mortality in heart transplantation

BACKGROUND

The current International Society for Heart and Lung Transplantation (ISHLT) diagnostic criteria for antibody-mediated rejection (AMR) designate AMR as either absent (AMR 0) or present (AMR 1), without grading its severity. Yet, the extent of histologic and immunofluorescence (IF) findings of AMR varies across endomyocardial biopsies (EMBs). In this study, we hypothesized that the severity of AMR, as assessed on EMBs, correlates with cardiovascular mortality in heart transplant recipients.

METHODS

All EMBs from 1985 to 2005 were evaluated. Biopsy specimens were uniformly studied by light microscopy and IF early post-transplant. A comprehensive vascular score (V1: no AMR, to V5: severe AMR) was prospectively assigned to each EMB, based on severity of both histologic and IF findings. Univariate Cox proportional hazards regressions were performed using indicators of vascular scores alone, combined, and cumulatively.

RESULTS

Nine hundred six patients were transplanted and included in the study. Mean age was 46.6 +/- 15.5 years and 82% were male. A total of 26,236 EMBs comprised the study data. As expected, histologic and immunopathologic findings of AMR varied in severity. An incremental risk of cardiovascular mortality was found with more severe AMR whether vascular scores were analyzed individually (p = 0.001), in combination (p = 0.01) or cumulatively (p = 0.006).

CONCLUSIONS

The severity of AMR on EMBs correlates with an incremental cardiovascular mortality risk after heart transplantation, suggesting that AMR should be viewed as a spectrum rather than just as present or absent. Supplementing the ISHLT AMR diagnostic guidelines with a consensus severity scale is warranted.

Treatment and prophylaxis of cardiac allograft vasculopathy

Cardiac allograft vasculopathy (CAV) remains a life-threatening complication after heart transplantation (HT). Recipients with severe intimal thickening are 10-fold more likely to suffer cardiac events than those without severe hyperplasia. From July 1987 to July 2007, we performed 323 HTs with 5-year actuarial freedom from CAV of 69%, similar to the data reported by the International Society for Heart and Lung Transplantation, namely, 68% at 5 years. Therefore, CAV is not uncommon in Asia. The pathogenesis of CAV is initial endothelial injury followed by intimal hyperplasia and proliferation of vascular smooth muscle cells. It may be caused by both immunological events (involving T or B cells in response to donor major histocompatibility antigens, or natural killer [NK] cell-triggered recruitment of T cells not responsive to donor alloantigen) and nonimmunologic factors, such as older age, ischemia-reperfusion injury, viral infection (particularly cytomegalovirus [CMV] infection), immunosuppressive drugs, and classic risk factors, such as hyperlipidemia, insulin resistance, and hypertension. The therapy for CAV has been disappointing, despite prescriptions of statin lipid-lowering agents, calcium-channel blockers, angiotensin-converting enzyme inhibitors, and antiproliferative drugs. Patients with CAV are often not amenable to successful revascularization (medical or surgical) because of the diffuse obliterative process. Prophylaxis of CAV starts with modification of risk factors: hypertension, hyperlipemia, hyperglycemia, obesity, and smoking, as well as promotion of exercise programs. The HMG-CoA reductase inhibitors and antiproliferative drugs may slow the progression of CAV by various immunologic and nonimmunologic effects. Prevention of CMV infection reduces CAV. Mycophenolate mofetil and signal transduction inhibitors, such as everolimus, reduce intimal thickening and CAV.

The experimental study of cardiac allograft vasculopathy and myocardial fibrosis in rats

We sought to analyze the development of myocardial fibrosis and cardiac allograft vasculopathy (CAV) as a theoretical basis for the prevention and treatment of rejection. Heterotopic cardiac transplantation was performed from Wistar rats to Sprague-Dawley rats. The recipients pretreated with donor splenocyte (SPC) infusion followed by cyclophosphamide (CP) were divided into 3 groups: Control animals without immunosuppression (Group 1; n = 10); Group 2, CsA treatment (n = 10) with euthanasia 2-3 months posttransplantation; and Group 3 (n = 20), CP plus SPC treatment with 10 recipients euthanized at 2 weeks posttransplantation and 10 animals monitored for at least 1 year posttransplantation. Histological studies were performed to evaluate myocardial fibrosis and CAV; 2-3 days after transplantation, there was abundant infiltration of collagenous fibers in the adventitia and intima of the coronary arteries in Group 1 allografts. Group 2 allografts demonstrated abundant infiltration of collagenous fibers in the adventitia and intima of arteries and arterioles resulting in significant luminal stenosis. In contrast, pretreatment of animals with SPC and CP induced long-term allograft survival; myocardial fibrosis and CAV were dramatically reduced in Group 3 compared with Groups 1 and 2. The infiltration of collagenous fibers in coronary arteries was one of the major causes of CAV. Preconditioning of recipients with SPC followed by CP not only induced immune tolerance but also alleviated myocardial fibrosis and CAV in allografts.

Automatic detection of regional heart rejection in USPIO-enhanced MRI

Contrast-enhanced magnetic resonance imaging (MRI) is useful to study the infiltration of cells in vivo. This research adopts ultrasmall superparamagnetic iron oxide (USPIO) particles as contrast agents. USPIO particles administered intravenously can be endocytosed by circulating immune cells, in particular, macrophages. Hence, macrophages are labeled with USPIO particles. When a transplanted heart undergoes rejection, immune cells will infiltrate the allograft. Imaged by T(2)(*)-weighted MRI, USPIO-labeled macrophages display dark pixel intensities. Detecting these labeled cells in the image facilitates the identification of acute heart rejection. This paper develops a classifier to detect the presence of USPIO-labeled macrophages in the myocardium in the framework of spectral graph theory. First, we describe a USPIO-enhanced heart image with a graph. Classification becomes equivalent to partitioning the graph into two disjoint subgraphs. We use the Cheeger constant of the graph as an objective functional to derive the classifier. We represent the classifier as a linear combination of basis functions given from the spectral analysis of the graph Laplacian. Minimization of the Cheeger constant based functional leads to the optimal classifier. Experimental results and comparisons with other methods suggest the feasibility of our approach to study the rejection of hearts imaged by USPIO-enhanced MRI.

[The pivotal role of the pathologist in transplantation]

The management of rejection has recently become more complex, in particular since the identification of antibody-mediated rejection in addition to the full-established pictures of cellular rejection. The pathologist who reads graft biopsies must solve these problems in order to arrive at a clear histopathological diagnosis. The diagnosis will then have to be discussed in a multidisciplinary approach with the clinical persons, in order to decide upon the optimal treatment approach. Protocol biopsies may detect subclinical rejection and, hence help adjust the immunosuppressive treatment for an extended allograft survival. Finally, allograft biopsies performed with the purpose of "staging" may yield helpful informations concerning the condition of the organ, and may thus help to anticipate a possible future re-transplantation.

Remodeling of human transplanted myocardium in ten-year follow-up: a clinical pathology study

Remodeling taking place in transplanted myocardium leads to a change in the number of cardiocytes. Ultrasound measurements and biopsy evaluation should reflect their loss and compensation. We sought to evaluate the morphology of the transplanted heart upon long-term follow-up.

MATERIAL AND METHODS

Myocardial biopsies were obtained in the first week, first month, and then annually for 10 years from transplantation that did not show rejection (grade "0" ISHLT, 122 biopsies). The control group encompassed 7 donor heart fragments. Proliferation in biopsies was evaluated with Ki67 (M7240, DAKO), cardiocyte hypertrophy by measuring their diameter, the surface area of the nuclei, nuclear-sarcoplasmic index, and stromal fibrosis evaluated as the surface area fraction. Ultrasound measurements included diastolic thickness of the interventricular septum, posterior wall of the left ventricle, and left ventricular mass. The correlation of measurements with time from transplantation was evaluated using Spearman's test.

RESULTS

A positive Ki67 reaction was observed in fibroblasts and endothelial cells. The increased cardiocyte nuclear area correlated with the time elapsed since transplantation (r = 0.2; P < .05) with a simultaneous decrease in cardiocyte thickness (r = -0.3; P < .05), without changes in the nuclear-cytoplasmic index (r = 0.02; P > .05). Stromal fibrosis also increased (r = 0.1; P < .05). Ultrasound measurements of the left ventricle showed a decreased tendency with the passage of time (r = -0.2 to -0.3; P < .05).

CONCLUSION

A transplanted heart does not undergo hypertrophy but rather fibrous atrophy with apparent compensatory hypertrophy of the cardiomyocytes.

[Clinicopathologic analysis of dilated heart in cardiac transplant recipients]

OBJECTIVE

To study the pathologic features of dilated heart in cardiac transplant recipients, with clinicoradiologic correlation.

METHODS

Sixty recipient hearts from cardiac transplantation performed in Fuwai Hospital were analyzed by gross examination, histologic observation and electron microscopy. Clinicoradiologic correlation was available in 40 cases.

RESULTS

Amongst the 40 cases of dilated heart, 52.5% (21/40) were due to dilated cardiomyopathy, 22.5% (9/40) due to arrhythmogenic right ventricular cardiomyopathy, 15.0% (6/40) due to ischemic cardiomyopathy, and the remaining 10.0% (4/40) due to miscellaneous causes, including local noncompaction of ventricular myocardium, giant cell myocarditis, alcoholic cardiomyopathy and hypertensive cardiomyopathy. The discrepancy rate between clinical and pathologic diagnosis was 37.5% (15/40). The erroneous categories included arrhythmogenic right ventricular cardiomyopathy (7 cases), ischemic cardiomyopathy (5 cases), and giant cell myocarditis (1 case), which were all mistaken clinically as dilated cardiomyopathy. While ischemic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, noncompaction of ventricular myocardium and giant cell myocarditis have distinctive pathologic features, the diagnosis of alcoholic and hypertensive cardiomyopathies required clinicopathologic correlation. Dilated cardiomyopathy due to viral myocarditis was not identified in the cases studied.

CONCLUSION

Pathologic examination is essential in analysis of transplant recipient heart and helps to rectify clinical diagnostic discrepancy.

PDL1 is required for peripheral transplantation tolerance and protection from chronic allograft rejection

The PD-1:PDL pathway plays an important role in regulating alloimmune responses but its role in transplantation tolerance is unknown. We investigated the role of PD-1:PDL costimulatory pathway in peripheral and a well established model of central transplantation tolerance. Early as well as delayed blockade of PDL1 but not PDL2 abrogated tolerance induced by CTLA4Ig in a fully MHC-mismatched cardiac allograft model. Accelerated rejection was associated with a significant increase in the frequency of IFN-gamma-producing alloreactive T cells and expansion of effector CD8(+) T cells in the periphery, and a decline in the percentage of Foxp3(+) graft infiltrating cells. Similarly, studies using PDL1/L2-deficient recipients confirmed the results with Ab blockade. Interestingly, while PDL1-deficient donor allografts were accepted by wild-type recipients treated with CTLA4Ig, the grafts developed severe chronic rejection and vasculopathy when compared with wild-type grafts. Finally, in a model of central tolerance induced by mixed allogeneic chimerism, engraftment was not abrogated by PDL1/L2 blockade. These novel data demonstrate the critical role of PDL1 for induction and maintenance of peripheral transplantation tolerance by its ability to alter the balance between pathogenic and regulatory T cells. Expression of PDL1 in donor tissue is critical for prevention of in situ graft pathology and chronic rejection.

Effect of posttraumatic donor's disseminated intravascular coagulation in intrathoracic organ donation and transplantation

INTRODUCTION

Our aim was to evaluate the influence on yield and function of intrathoracic organs from donors after severe cranial trauma complicated by disseminated intravascular coagulation (DIC).

MATERIALS AND METHODS

This retrospective observational study in a patient cohort with severe cranial trauma reading to brain death compared the number of harvested thoracic organs among individuals with versus without previous DIC. We examined exclusions for organ donation and their probable relationship to DIC. We also analyzed blood components transfused to normalize coagulation parameters. The organ recipients were followed for 1 month to detect acute graft failure.

RESULTS

Among 147 organ donors, 37 were brain dead after suffering severe cranial trauma and 13 met DIC criteria upon admission. We did not observe demographic differences among donors, although there was a trend for DIC donors to be younger (32 +/- 10 vs 40 +/- 21 years old; P = .11). Twenty-eight donors (12 with DIC and 16 without) and 29 donors (13 with DIC and 16 without) met age and medical criteria for potential heart or lung donation, respectively. Donation exclusion was related to trauma instead of DIC itself. We did not find any difference among the number of cardiac and lung organs harvested from organ donors with DIC (67% and 31%, respectively) or without DIC (75% and 44%, respectively). All DIC donors had clinical bleeding and received multiple units of blood products. Organs were harvested 37 +/- 23 (13 to 80) hours after admission. All patients had normalized coagulation parameters at surgery. In the postoperative evolution, none of the cardiac or lung recipients from DIC donors met primary graft failure criteria.

CONCLUSIONS

We concluded that hearts and lungs from donors with previous DIC were suitable for transplant recipients.