Solid-organ transplantation in older adults: current status and future research.

An increasing number of patients older than 65 years are referred for and have access to organ transplantation, and an increasing number of older adults are donating organs. Although short-term outcomes are similar in older versus younger transplant recipients, older donor or recipient age is associated with inferior long-term outcomes. However, age is often a proxy for other factors that might predict poor outcomes more strongly and better identify patients at risk for adverse events. Approaches to transplantation in older adults vary across programs, but despite recent gains in access and the increased use of marginal organs, older patients remain less likely than other groups to receive a transplant, and those who do are highly selected. Moreover, few studies have addressed geriatric issues in transplant patient selection or management, or the implications on health span and disability when patients age to late life with a transplanted organ. This paper summarizes a recent trans-disciplinary workshop held by ASP, in collaboration with NHLBI, NIA, NIAID, NIDDK and AGS, to address issues related to kidney, liver, lung, or heart transplantation in older adults and to propose a research agenda in these areas.

Regulation of human aortic endothelial cell-derived mesenchymal growth factors by allogeneic lymphocytes in vitro. A potential mechanism for cardiac allograft vasculopathy.

Cardiac allograft vasculopathy is thought to be triggered by an alloreactive response to the donor coronary vasculature, resulting in smooth muscle cell proliferation and ultimate occlusion of the donor coronary arteries. To determine whether allogeneic lymphocytes are capable of regulating endothelial-derived smooth muscle cell (SMC) growth factors, human aortic endothelial cells (HAECs) were exposed to allogeneic lymphocytes. The HAEC-lymphocyte co-cultures were assessed for (a) lymphocyte proliferation in response to the allogeneic HAECs; (b) release of soluble factors that stimulate human aortic SMC proliferation; and (c) alteration of HAEC mRNA levels for a panel of known SMC growth factors. Co-culture conditioned medium increased SMC proliferation, compared to medium conditioned by HAECs alone. HAECs exposed to allogeneic lymphocytes increased their expression of mRNA for basic fibroblast growth factor, transforming growth factors alpha and beta, and platelet derived growth factor A and B chains. These results demonstrate that allogeneic lymphocytes are capable of inducing HAECs to increase mRNA levels for several mesenchymal growth factors and to release bioactive products capable of stimulating SMC cell proliferation in vitro. Additionally, the data support the hypothesis that alloreactive lymphocytes can stimulate allogeneic donor endothelial cells to produce growth factors that may contribute to the intimal thickening seen in cardiac allograft vasculopathy.

Lack of objective improvement in ventricular systolic function in patients with myocarditis treated with azathioprine and prednisone.

Six patients with myocarditis documented by biopsy, after a baseline right heart catheterization and echocardiogram, underwent treatment with azathioprine and prednisone. After 3 months of treatment, biopsy, right heart catheterization and echocardiogram were repeated. In addition to the immunosuppressive therapy, most patients received additional conventional medications for heart failure between evaluation periods (mean number of cardiac drugs increased from 1.7 +/- 1.0 to 2.7 +/- 0.05, p = 0.041). Mean heart rate decreased (105 +/- 14 to 84 +/- 13 beats/min, p = 0.016), as did pulmonary wedge pressure (23 +/- 8 to 12 +/- 4 mm Hg, p = 0.012). There were no significant changes in cardiac index (3.1 +/- 0.8 to 2.9 +/- 1.0 liters/min), end-diastolic dimension (62 +/- 13 to 62 +/- 12 mm) or fractional shortening (11 +/- 6 to 12 +/- 3%) with treatment. Complications from immunosuppressive therapy included severe soft tissue infection, acute psychosis and adrenal insufficiency in one patient each. The benefits from prednisone and azathioprine in this group of patients have not been demonstrated. Although heart rate and pulmonary wedge pressure decreased, these changes could be ascribed to increases in the conventional therapy for heart failure. Finally, there is a high incidence of side effects from prednisone and azathioprine therapy. These findings suggest that this unproven therapy for myocarditis should be limited to experimental protocols.

Exercise induced augmentation of cellular and humoral autoimmunity associated with increased cardiac dilatation in experimental autoimmune myocarditis.

To determine the effects of exercise in experimental autoimmune myocarditis, guinea pigs immunised with heterologous heart protein (rat heart), Freund's complete adjuvant, and pertussis vaccine (treated group) were exercised on a treadmill for a total of 11 weeks and compared with non-exercise treated animals. In vivo heart rates and pressures, in vitro left ventricular pressure-volume relations, myocardial histology, circulating antiheart antibody, and in vitro lymphocyte stimulation were determined. Exercise resulted in increased cardiac dilatation in treated animals as assessed by in vitro left ventricular pressure-volume relations compared with non-exercise treated animals (at 8 mmHg 1.41(0.17) ml.kg-1 vs 1.20(0.17) ml.kg-1 respectively, p less than 0.005). Exercise also resulted in increased concentrations of circulating antiheart antibody as assessed by radioimmunoassay (0.14(0.04) microgram vs 0.10(0.03) microgram respectively, p = 0.01), and increased lymphocyte activation to specific antigen (stimulation index 3.7(0.07) vs 2.4(1.0) respectively, p less than 0.001). Despite the associated augmentation of autoimmunity with cardiac dilatation, there were no differences in the histopathological findings between the exercised treated and the non-exercised treated animals either qualitatively or quantitatively (number of inflammatory cell microaggregates). This finding suggests that, although the immune system is important in experimental autoimmune myocarditis, the amount of inflammation and necrosis does not appear to correlate with the degree of left ventricular dilatation and presumed dysfunction.

Experimental autoimmune myocarditis in the guinea pig.

Male and female guinea pigs underwent immunisation with heterologous heart protein (rat heart), complete Freund's adjuvant and pertussis vaccine (immunised) or normal saline (control) at weekly intervals for 6 weeks, and were subsequently studied. In vivo intracardiac pressures, cardiac outputs, blood volumes, in vitro pressure-volume relations, left ventricular collagen contents, light microscopy, direct immunofluorescence, lymphocyte stimulation studies, and serology for circulating anti heart antibody (haemagglutination and radioimmunoassay) were performed. Immunised guinea pigs studied between 5 and 8 weeks following the immunisation protocol demonstrated a 44% increase in LVEDP (p less than 0.005), an increase in right atrial pressure (p less than 0.001), although no change in aortic pressure or cardiac output when compared with controls. Left ventricular weight was increased 20% (p less than 0.001), and in vitro left ventricular volume by 34% (at 8 mmHg distending pressure, p less than 0.001). Lung wet weight was increased 44% (p less than 0.005), and left ventricular collagen content increased 60% (p less than 0.001). Cultured lymphocytes from treated guinea pigs demonstrated a 1.5- to 4.5-fold (dependent upon proximity to last immunisation) increase in radiolabelled thymidine uptake when incubated with guinea pig heart protein compared to controls (p less than 0.001), and circulating anti guinea pig heart antibodies were detected by haemagglutination and radioimmunoassay. Histological examination of the left ventricles revealed inflammatory cell infiltration and myocyte increase to varying degrees in 15 of the 18 treated animals. We conclude that inflammatory, probably immune-mediated, chronic myocarditis can be produced in the guinea pig.

Abnormal pulmonary function specifically related to congestive heart failure: comparison of patients before and after cardiac transplantation.

PURPOSE: A variety of abnormalities in pulmonary function have been attributed to, or are believed to be, exacerbated by congestive heart failure. Separating out specific contributions from cardiac versus pulmonary disease is difficult. In order to investigate the impact of cardiac disease on pulmonary function, we performed spirometry on patients immediately before and after cardiac transplantation. PATIENTS AND METHODS: Seventeen patients (13 men, 4 women) with a mean age of 44 years (range: 20 to 62 years) were studied before and 15 +/- 10 (mean +/- SD) months after cardiac transplantation. Eleven patients had a significant smoking history. RESULTS: In comparing pre- and post-transplant spirometric results, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) increased substantially after transplant (3.34 +/- 0.96 L versus 3.89 +/- 1.00 L, p = 0.0054, and 2.63 +/- 0.80 L versus 2.95 +/- 0.83 L, p = 0.042, respectively). FEV1/FVC was not significantly different between study states in the entire group (0.78 +/- 0.10 versus 0.76 +/- 0.10, p = NS), nor was it different in those patients with and without a smoking history (0.76 +/- 0.11 versus 0.72 +/- 0.10, p = NS, and 0.87 +/- 0.06 versus 0.84 +/- 0.02, p = NS, respectively). Furthermore, normal lung volumes were obtained after transplant in those patients without a smoking history in contrast to those with a smoking history. Finally, the increase in FVC after cardiac transplantation directly correlated with the decrease in cardiac volume with cardiac replacement (r = 0.83, p less than 0.0001). CONCLUSION: We conclude that in patients selected as cardiac transplant candidates (those without severe obstructive lung disease), restrictive but not obstructive pulmonary physiology can be attributed in part to congestive heart failure, and a major part of the reduction in lung volumes is secondary to the space occupied by a large heart. Other factors, such as accompanying pleural effusions and interstitial edema, likely contribute to the reduction in lung volumes. Abnormal pulmonary function secondary to chronic congestive heart failure in this selected population is completely reversible with normalization of cardiovascular physiology and anatomy.

Myocardial perfusion abnormalities in asymptomatic patients with systemic lupus erythematosus.

Accelerated coronary artery disease and myocardial infarction in young patients with systemic lupus erythematosus is well documented; however, the prevalence of coronary involvement is unknown. Accordingly, 26 patients with systemic lupus were selected irrespective of previous cardiac history to undergo exercise thallium-201 cardiac scintigraphy. Segmental perfusion abnormalities were present in 10 of the 26 studies (38.5 percent). Five patients had reversible defects suggesting ischemia, four patients had persistent defects consistent with scar, and one patient had both reversible and persistent defects in two areas. There was no correlation between positive thallium results and duration of disease, amount of corticosteroid treatment, major organ system involvement or age. Only a history of pericarditis appeared to be associated with positive thallium-201 results (p less than 0.05). It is concluded that segmental myocardial perfusion abnormalities are common in patients with systemic lupus erythematosus. Whether this reflects large-vessel coronary disease or small-vessel abnormalities remains to be determined.

Mycophenolate mofetil versus azathioprine in patients surviving the initial cardiac transplant hospitalization: an analysis of the Joint UNOS/ISHLT Thoracic Registry.

BACKGROUND: Although the randomized mycophenolate mofetil- (MMF) azathioprine (AZA) trial is likely applicable to cardiac transplantation in general, it was limited to select and usually larger cardiac transplant centers and suffered from substantial cross-over and failure of many patients to receive assigned treatment drug. METHODS: The Joint ISHLT/UNOS Thoracic Registry was analyzed for the effects of MMF versus AZA in patients 1) on a cyclosporine- (CsA) based immunosuppression protocol; 2) having survived long enough to be discharged from the transplant hospitalization. RESULTS: A total of 5599 patients (4942 CsA/AZA and 657 CsA/MMF) were included with no significant differences between the MMF and AZA groups in baseline characteristics with the exception of recipient age (50 vs. 47 years), donor age (29 vs. 28 years), ischemic time (3.0 vs. 2.9 hr), and pretransplant medical condition (more AZA patients in ICU, more MMF patients on VAD). Actuarial survival was greater in the MMF group compared to the AZA group in patients surviving the initial transplant hospitalization (1 year 96 vs. 93%, 3 years 91 vs. 86%, P=0.0012). This difference was confirmed in the logistic regression analysis of 3-year mortality showing a relative risk of 0.62 (P=0.011). CONCLUSIONS: These data provide independent support for the broad applicability of the positive results from the randomized MMF-AZA clinical trial in a substantially larger patient population and confirm improved survival in patients using mycophenolate mofetil compared to azathioprine late after cardiac transplantation.

Cyclosporine induces the expression of the cyclin inhibitor p21.

BACKGROUND: Current immunosuppression strategies involve inhibition of T cell activation and/or lymphocyte proliferation. During T cell cycle progression/activation, the expression of cyclins and cyclin dependent kinases is increased. In this study, we examined whether cyclosporine A (CsA) suppresses the cell cycle progression through the induction of the cell cycle inhibitor p21. Because CsA induces the expression of transforming growth factor (TGF)-beta, and TGF-beta induces p21 expression, we also determined whether CsA's induction of p21 is dependent on or independent of TGF-beta. METHOD: Using reverse transcription assisted polymerase chain reaction and western blot analysis, we studied the induction of p21 mRNA and protein in human T cells and A-549 cells (human lung adenocarcinoma cells) by CsA. The stimulation of p21 promoter activity was studied by luciferase assay using p21-luc, chimeric plasmid DNA containing a p21 promoter segment, and luciferase reporter gene. The dependence of CsA's induction of p21 was studied using anti-TGF-beta antibody and TGF-beta altered A-549 cells. RESULTS: CsA induced p21 mRNA protein expression and stimulated its promoter activity in lymphoid (T cells) and nonlymphoid (human lung adenocarcinoma, A-549 cells).CsA's induction of p21 was inhibited both by a neutralizing anti-TGF-beta antibody and in TGF-beta-altered A-549 cells, consistent with its effects on p21 requiring TGF-beta. CONCLUSION: These data support the hypothesis that at least one component of CsA's antiproliferative effects may occur through the induction of p21 and that this induction is dependent on TGF-beta. Should p21 induction be a viable immunosuppressive strategy, inducing this molecule independent from the fibrogenic cytokine TGF-beta might reduce the toxicity associated with current immunosuppression.

Coronary venous intimal thickening in explanted cardiac allografts. Evidence demonstrating that transplant coronary artery disease is a manifestation of a diffuse allograft vasculopathy.

The accelerated coronary artery disease occurring in cardiac allografts is thought to be a form of chronic rejection directed against allogeneic vascular endothelium. If this hypothesis is correct, one would anticipate disease not only in the arteries but in venous structures as well. Accordingly, the degree of myointimal proliferation of both coronary arteries and coronary veins was assessed in 22 explanted or autopsied cardiac allografts by light microscopy. Other factors assessed included clinical cause of death/retransplantation, time posttransplantation, underlying cardiac disease, donor and recipient age, and ischemic time. Thirteen of the 22 hearts had either moderate or severe arterial myointimal thickening. Of these, 10 hearts had associated coronary venous thickening. Of the 9 remaining hearts with either mild or no arterial myointimal thickening, none had venous involvement. The overall correlation between the presence and degree of allograft coronary artery and allograft coronary vein thickening was high (r = 0.80, P = 0.0014). Of the other demographic factors investigated, only length of time posttransplant had a weak correlation with arterial or venous myointimal thickening (r = 0.46, P = 0.045 and r = 0.48, P = 0.039, respectively. These data demonstrate that the usually termed "accelerated transplant atherosclerosis" in the cardiac allograft is a true vasculopathy and involves both the arterial and venous systems.

Tacrolimus induces increased expression of transforming growth factor-beta1 in mammalian lymphoid as well as nonlymphoid cells.

BACKGROUND: We and others have reported that cyclosporine (CsA) induces increased expression of transforming growth factor-beta1 (TGF-beta1) in vitro as well as in vivo. In view of similarities between tacrolimus and CsA with respect to immunosuppressive mechanisms, we determined whether tacrolimus, in a fashion similar to CsA, induces TGF-beta1 hyperexpression in mammalian cells. METHODS: We studied the induction of TGF-beta1 mRNA by tacrolimus using reverse transcription-polymerase chain reaction and Northern blot analysis in normal human T cells and A-549 cells (human lung adenocarcinoma cell line), a cell line used to study the biology of TGF-beta and the induction of TGF-beta1 by CsA. We also measured the induction of TGF-beta1 protein by tacrolimus in activated human T cells, peripheral blood mononuclear cells, and A-549 cells, using sandwich enzyme-linked immunosorbent assay. RESULTS: A significant increase in the TGF-beta1 mRNA expression was observed after treatment of T cells or A-549 cells. Tacrolimus treatment resulted also in heightened production of TGF-beta1 protein by activated T cells, A-549 cells, or peripheral blood mononuclear cells activated with anti-CD3, phytohemagglutinin, and concanavalin A. CONCLUSIONS: Our observations that tacrolimus stimulates TGF-beta1 hyperexpression in mammalian cells suggest a unifying mechanism for the immunosuppressive as well as nephrotoxic properties of tacrolimus, as the multifunctional TGF-beta1 is a potent immunosuppressive and fibrogenic cytokine.

The results of cardiac retransplantation: an analysis of the Joint International Society for Heart and Lung Transplantation/United Network for Organ Sharing Thoracic Registry.

BACKGROUND: It is well established that repeat heart transplantation has a significantly worse outcome when compared with primary (first time) transplantation. Defining the risk factors for mortality within this group has been difficult due to small numbers of patients at individual centers. METHODS: All cardiac retransplants performed in the United States and registered in the Joint International Society for Heart and Lung Transplantation (ISHLT)/United Network for Organ Sharing (UNOS) Thoracic Registry were analyzed for demographics, morbidity posttransplantation, immunosuppression, and risk factors for mortality. RESULTS: The study cohort included 514 patients of which 81% were male with a mean age of 47+/-12 years. Time from primary transplant to retransplantation ranged from 1 day to 15.5 years and more than 50% of the patients underwent retransplantation for chronic rejection. More than 60% of patients were in the intensive care unit at the time of retransplantation and more than 40% of the patients were reported to be on some form of life support (ventricular assist device, ventilator, and/or inotropic therapy). Survival for the entire retransplant cohort was 65, 59, and 55% for 1, 2, and 3 years, respectively, but was substantially lower when the intertransplant interval was short. Conversely, when the interval between primary and retransplantation was more than 2 years, 1 year survival postretransplantation approached that of primary transplantation. Additional independent risk factors for mortality for the retransplant cohort included overall cardiac transplant center volume, the use of a ventricular assist device or ventilator, the patient being in the intensive care unit, and recipient age. The four most common causes of death were infection, primary/nonspecific graft failure, chronic rejection (allograft vasculopathy), and acute rejection. CONCLUSIONS: The data confirm that repeat heart transplantation is a higher risk procedure than primary transplantation, especially early after the primary heart transplant.

Cardiac allograft vasculopathy: IgM antibody responses to donor-specific vascular endothelium.

We have previously demonstrated that heightened cell-mediated immunity to donor-specific endothelium was associated with an increased incidence of cardiac allograft vasculopathy (CAV) at 1 year postcardiac transplantation. We further demonstrated that the development of IgG antibody directed to donor-specific HLA antigens was extremely uncommon and, furthermore, had no relationship to the development of CAV. Subsequent studies have demonstrated a correlation between IgM antibody directed against endothelial cell antigens and the development of CAV. Accordingly, recipient serum obtained between 6 and 8 weeks (early) and 1 year (late) after transplantation were reacted with recombinant human interferon (rhIFN)-gamma pretreated donor-specific human aortic endothelial cells (HAECs) in 10 recipients with and 10 recipients without CAV at 1 year after transplantation. HAEC IgM binding was assessed by flow cytometry and complement fixation and HAEC lysis was measured using standard chromium release assays. Seven of 10 and 5 of 10 patients with CAV had IgM detected by flow at early and late time points, respectively (14+/-2 and 16+/-5 mean channel shift), whereas 5 of 10 and 6 of 10 patients without CAV had IgM detected by flow at early and late time points, respectively (15+/-4 and 14+/-3 mean channel shift). This finding was not different between groups. Despite between 50% and 70% of all patients having detectable IgM binding to ECs, no patient's serum was cytotoxic to its donor-specific HAECs. We conclude that IgM antibody to endothelial cells is common (at low titers) after transplantation. This antibody is not cytotoxic and in this study provided no discrimination between those with and without chronic rejection.

Cytomegalovirus-induced regulation of major histocompatibility complex class I antigen expression in human aortic smooth muscle cells.

Cardiac allograft vasculopathy (accelerated transplant atherosclerosis) is considered by most to involve a chronic allogeneic immune response to one or more constituents in the coronary vascular wall. Recent evidence suggests that there is an association between cytomegalovirus infection and the development of cardiac allograft vasculopathy (CAV). To determine whether CMV directly infects and/or potentially influences immunogenicity of vascular tissue, human umbilical vein (HU-VECs) or human aortic (HAECs) endothelial cells and human aortic smooth muscle cells (HASMCs) were isolated, cultured, and infected with CMV strain AD 169. Infection was detected using an immunoperoxidase-labeled monoclonal antibody to CMV immediate-early antigen (L-14). The presence and relative quantity of MHC class I and II antigens were determined flow cytometrically using monoclonal antibodies to monomorphic class I and class II HLA determinants. Gamma interferon was used as a positive control stimulant for the upregulation of MHC determinants. Both pooled HUVECs as well as 2 cell lines of HAECs served as targets for CMV infection though less than 10% of the cells were infected despite inocula of 10 pfu/cell. Infection of the pooled HUVECs resulted in no significant changes in the cell surface density of either MHC class I or II determinants. In contrast, HASMCs were excellent targets for CMV infection with virtually 100% of cells infected. CMV infection of 2 distinct HASMC cultures resulted in an increase of 254 +/- 158 relative fluorescence units (RFUs) in MHC class I antigen expression, as assessed by fluorescence intensity, in a variable portion of the HASMCs. A second population of cells exhibited a decrease of 73 +/- 16 RFUs in MHC class I antigen expression. No significant change in MHC class II antigen expression was noted. These results demonstrate that while HUVECs and HAECs are targets of CMV infection, human aortic smooth muscle cells can more readily be infected by CMV. Furthermore, CMV can regulate smooth muscle cell MHC class I expression, hence potentially altering immunogenicity. A pathophysiologic link between cardiac allograft vasculopathy and CMV disease can therefore be hypothesized.

The relationship between acute rejection and chronic rejection is highly dependent on specific MHC matching: a multi-strain rat heterotopic heart transplant study.

BACKGROUND: The impact of acute rejection, immunosuppression, and infection, specifically cytomegalovirus infection, on the development of chronic rejection in the cardiac allograft, has been the subject of a large number of investigations. One of the difficulties in finding associations has been the marked immunologic heterogeneity of the patient population coupled with the lack of the ability to HLA match. Furthermore, the ideal animal model, which duplicates as well as controls for this immunologic heterogeneity, is lacking. METHODS: To try to simulate differences in HLA matching, immunosuppression regiments and cytomegalovirus infection, heterotopic heart transplantation was performed in two separate, complete MHC mismatch, rat strain combinations (WF-LEW, BN-LEW) requiring chronic immunosuppression and employing four separate immunosuppression/infection protocols. Animals were followed for 6 months, killed, and rejection and vascular changes were scored blinded to the group. RESULTS: The mean vascular and acute rejection scores were not significantly different between treatment regiments for either specific strain combination. There was a trend for the subtherapeutic groups to have higher vascular scores. Overall, there were no significant differences in vascular scores between the WF-LEW and BN-LEW groups (1.25+/-0.18 vs. 1.13+/-0.20, P=NS). Similar numbers of WF-LEW and BN-LEW exhibited cellular infiltration and necrosis of the allograft, but the intensity of the response (rejection score) was more severe in the WF-LEW combination (4.54+/-0.22 vs. 3.92+/-0.21, P=0.052) when limiting the analysis to those with myocyte necrosis. There was no significant correlation between acute rejection and vascular lesion severity in the WF-LEW combination (r=0.22, P=NS) but a high correlation between these parameters in the BN-LEW combination (r=0.74, P<0.0001). CONCLUSIONS: These data suggest that, although acute rejection and chronic rejection are related, MHC matching may influence their interdependence. These data also may explain why the clinical association between acute and chronic rejection is difficult to demonstrate.

The modulation of human aortic endothelial cell ICAM-1 (CD-54) expression by serum containing high titers of anti-HLA antibodies.

Allograft recipients who have preformed antibodies to MHC determinants or develop these antibodies post-transplantation have a higher incidence of cellular rejection and graft loss. It is unclear whether this association is an etiologic one or whether the presence of these antibodies solely identifies individuals with a more pronounced alloimmunologic response. To determine whether antibodies to MHC determinants have a direct role in enhancing cell-mediated immunity, specifically in altering effector-target cell adhesion, the expression of endothelial cell surface intercellular adhesion molecule-1 (ICAM-1) in response to serum with high-titer anti-HLA antibodies was investigated. The target cells used were a pool of blood group O human aortic endothelial cells (HAECs) representing a wide range of HLA-A, B, C, and DR phenotypes. The test serum was serum pooled from 30 highly sensitized individuals (panel-reactive antibody 80%). Antibody binding to HAECs, and HAEC expression of class I and class II major histocompatibility (MHC) antigens and ICAM-1 were assessed by flow cytometry. General HAEC metabolic changes were assessed by 3H-uridine incorporation as a measure of RNA synthesis. Test serum resulted in almost a 14-fold increase in HAEC surface ICAM-1 expression compared with control serum, and titrations of test serum yielded a strong correlation between IgG bound to HAECs and HAEC ICAM-1 expression (r = 0.92). Test serum induced no change in expression of HAEC class I or class II MHC antigens, or 3H-uridine incorporation. The HAEC ICAM-1-inducing ability of the test serum was retained by concentrating the high molecular weight (> 100 kilodaltons) fraction of the test serum, isolation and purification of IgG from the test serum, and lost by absorbing this fraction with pooled platelets, suggesting that the activity was mediated by antibodies directed against MHC class I determinants. These data suggest that the presence of anti-HLA antibodies is more than a marker for individuals with greater alloreactive responsiveness. Anti-HLA antibodies may directly and specifically alter adhesion of effector cells to the allograft.

Outcomes in recipients of combined heart-kidney transplantation: multiorgan, same-donor transplant study of the International Society of Heart and Lung Transplantation/United Network for Organ Sharing Scientific Registry.

In patients awaiting heart transplantation, end-stage disease of a second organ may occasionally require consideration of simultaneous multiorgan transplantation. Outcome statistics in multiorgan transplant recipients are needed to define optimal utilization of scarce donor resources. Incidence of cardiac allograft rejection, actuarial recipient survival, and cardiac allograft rejection-free survival were evaluated in 82 recipients of 84 simultaneous heart and kidney transplants. Twenty-three of the 82 dual-organ recipients have died with 1, 6, 12, and 24-month actuarial survival rates of 92%, 79%, 76%, and 67%, respectively. The actuarial survival rates in the heart-kidney recipients were similar to those observed in 14,340 isolated heart recipients (United Network for Organ Sharing Scientific Registry) during the same period (92%, 86%, 83%, and 79%, respectively; P=0.20). Clinical data on all episodes of treated rejection in either organ and on immunosuppressive regimens were available on 56 patients; 48% of these patients have had no rejection in either organ, 27% experienced heart rejection alone, 14% experienced kidney rejection alone, and 11% had both heart and kidney allograft rejection. Heart allograft rejection was less common in heart-kidney recipients, as compared with isolated heart transplant recipients; 0, 1, and > or = 2 treated cardiac allograft rejection episodes occurred in 63%, 20%, and 18% of heart-kidney recipients compared with 46%, 27%, and 28% of 911 isolated heart recipients reported by Transplant Cardiologists' Research Database (P=0.02). The rejection-free survival rates at 1, 3, and 6 months were 88%, 74%, and 71% in the double-organ recipients, as compared with 66%, 44%, and 39%, respectively, in the single-organ recipients. Compared with isolated heart transplantation, combined heart-kidney transplantation does not adversely affect intermediate survival and results in a lower incidence of treated cardiac allograft rejection. The findings suggest that combined heart-kidney transplantation may be an acceptable option in a small subset of potential heart transplant recipients with severe renal dysfunction.

Strain specific effects of cytomegalovirus on endothelial cells: implications for investigating the relationship between CMV and cardiac allograft vasculopathy.

BACKGROUND: Cytomegalovirus (CMV) has been associated with the development of chronic allograft rejection. Attempts to delineate pathogenetic mechanisms for this association have characteristically used well-established laboratory strains for in vitro investigation and rodent strains for in vivo studies. There is substantial genetic heterogeneity not only among different laboratory strains, but also between laboratory strains and clinical isolates, and genetic differences between human and animal strains are profound. Given these genetic differences, one would anticipate differences in biological activity between strains. METHODS: Vascular endothelial cells were infected with two laboratory strains of CMV (Towne and AD-169) as well as two individual clinical CMV isolates, after genetic typing with six segments of the genome (including early and late genes). mRNA expression coding for a panel of mesenchymal growth factors was studied using quantitative reverse transcription, polymerase chain reaction. Major histocompatibility complex (MHC) expression was investigated using flow cytometry. RESULTS: There was substantial genetic variability between clinical and laboratory isolates. There did not appear to be differences in overall infectivity by the different strains as determined by expression of immediate-early antigen at 24 hours (5-10% of endothelial cells positive for immediate-early. Two growth factors, platelet-derived growth factor-A and basic fibroblast growth factor were augmented by one of the two clinical strains of CMV (Clin 2) (P=0.0091 and P=0.0018, respectively). Transforming growth factor -alpha and insulin-like growth factor expression were significantly reduced by both clinical strains and AD-169. Two other growth factors, heparin-binding epidermal growth factor and transforming growth factor-beta were not altered by infection with any strain. No strain altered MHC class II expression. MHC class I expression was increased with one of the two clinical strains (Clin 1, P=0.0006) and decreased by AD-169 (P=0.0016). Clin 2 and Towne had no effect on MHC class I expression. CONCLUSIONS: These data demonstrate that the genetic heterogeneity of CMV is associated with differences in transplant-relevant biologic activity even among clinical isolates. The relationship between CMV and chronic rejection may be difficult to determine given the heterogeneous nature of this complex virus.

Cardiac allograft vasculopathy. Preferential regulation of endothelial cell-derived mesenchymal growth factors in response to a donor-specific cell-mediated allogeneic response.

We have previously reported that cell-mediated immunity to vascular endothelium is associated with the development of cardiac allograft vasculopathy (CAV). The mechanism by which a cell-mediated immune response to the coronary vascular is translated into the development of CAV is, however unknown. Peripheral blood mononuclear cells (PBMCs) obtained serially following cardiac transplantation were cocultured with donor-specific human aortic endothelial cells (HAECs) in 47 allograft recipients, 9 of whom had CAV (CAV+) at 1 year by angiography. At 20 hr following coculture, HAEC poly (A+) RNA was isolated, reverse-transcribed, and the cDNA-amplified (PCR) for a panel of growth factors (GFs) known to alter smooth muscle cell proliferation or migration. Relative quantitation of PCR product was performed using high-pressure liquid chromatography (HPLC). Three patterns of GF regulation were observed depending on the GF, the time posttransplant, and whether the patient had CAV: (1) no regulation (TGF-beta, PDGF-A early post-tx); (2) upregulation irrespective of CAV (bFGF, PDGF-B, TGF-alpha early post-tx); and (3) preferential or exclusive upregulation by CAV+ patients (PDGF-A and TGF-alpha late post-tx, HB-EGF early and late post-tx). For example, using PBMCs as stimulators, obtained 6 months posttransplant from CAV+ patients, increases in HAEC-derived PDGF-A chain (31 +/- 7 to 69 +/- 11), TGF-alpha (97 +/- 27 to 201 +/- 23), and HB-EGF (78 +/- 16 to 173 +/- 27) mRNA were demonstrated (all P<0.05 or greater using HPLC peak area as units). These data demonstrate that cell-mediated activation of vascular endothelial cells in patients with CAV results in preferential upregulation of certain endothelial-derived mesenchymal growth factors capable of stimulating smooth muscle cell proliferation and migration.

Transforming growth factor (TGF)-beta mimics and anti-TGF-beta antibody abrogates the in vivo effects of cyclosporine: demonstration of a direct role of TGF-beta in immunosuppression and nephrotoxicity of cyclosporine.

BACKGROUND: Cyclosporine (CsA) has been shown to induce the expression of transforming growth factor (TGF)-beta both in vitro and in vivo. It is hypothesized that the efficacy as well as the side effects of CsA are mediated by TGF-beta. This study was planned to investigate whether anti-TGF-beta mitigated and TGF-beta reproduced the in vivo effects of CsA to directly prove this hypothesis. METHODS: B6AF1 (H2b/k.d) mice were divided into groups and received the following: CsA, vehicle (olive oil), CsA + anti-TGF-beta1 antibody, TGF-beta1, or vehicle phosphate-buffered saline/bovine serum albumin. All studies were carried out at 10 and 28 days after the last day of CsA administration with the exception of the exogenous TGF-beta experiments, which were performed 5 days after exogenous TGF-beta administration. The efficacy was studied by the anti-CD3-induced ex vivo proliferation of splenocytes measured by [3H]thymidine uptake; TGF-beta protein levels were quantified by ELISA. TGF-beta, collagen, and fibronectin gene expression was studied using reverse transcriptase-polymerase chain reaction, and histopathological analysis was made on periodic acid-Schiff- and trichrome C-stained thin kidney sections. RESULTS: CsA treatment resulted in decreased ex vivo proliferation of splenocytes, an increase in TGF-beta protein in the sera, and renal histopathological changes including tubular swelling, vacuolization, thrombotic microangiopathy, and increased expression of TGF-beta, collagen and fibronectin genes. All of these findings were blocked by anti-TGF-beta antibody. CONCLUSION: The study demonstrates the in vivo modulation of the effects of CsA by manipulating TGF-beta levels and suggests that TGF-beta at least in part mediates CsA's beneficial and detrimental effects.