Single Nucleotide Polymorphisms and Long-Term Clinical Outcome in Renal Transplant Patients: A Validation Study.

Genome-wide association studies (GWAS) are designed to investigate single nucleotide polymorphisms (SNPs) and the association with a clinical phenotype. A previous GWAS performed in 300 renal transplant recipients identified two SNPs (rs3811321 and rs6565887) associated with serum creatinine and clinical outcome. We sought to validate these findings. Genotyping of the two SNPs was performed using Taqman assays in 1638 Caucasians participating in the Assessment of LEscol in Renal Transplant (ALERT) study. Primary endpoint was death-censored graft loss, and secondary endpoint was all-cause mortality. Applying Cox regression, no crude association to graft loss was found for rs3811321 on chromosome 14 (hazard ratio [HR] 0.87, 95% CI 0.59-1.29, p = 0.50) or rs6565887 on chromosome 18 (HR 0.88, CI 0.62-1.25, p = 0.48). Multivariable adjustments did not change results, nor did evaluation of the number of risk alleles formed by the two SNPs. No association with mortality was detected. In conclusion, an impact of two SNPs on chromosomes 14 and 18 on death-censored graft survival or all-cause mortality was not confirmed. Our results emphasize the importance of validating findings from high-throughput genetics studies and call for large collaborative research initiatives in the field of transplantation outcomes.

Immunological profiling of haemodialysis patients and young healthy individuals with implications for clinical regulatory T cell sorting.

With the increasing interest in clinical trials with regulatory T cells (Tregs), immunological profiling of prospective target groups and standardized procedures for Treg isolation are needed. In this study, flow cytometry was used to assess peripheral blood lymphocyte profiles of young healthy individuals and patients undergoing haemodialysis treatment. Tregs obtained from the former may be used in haematopoietic stem cell transplantation and Tregs from the latter in the prevention of kidney transplant rejection. FOXP3 mRNA expression with accompanying isoform distribution was also assessed by the quantitative reverse transcriptase polymerase chain reaction. Flow-cytometric gating strategies were systematically analysed to optimize the isolation of Tregs. Our findings showed an overall similar immunological profile of both cohorts in spite of great differences in both age and health. Analysis of flow-cytometric gating techniques highlighted the importance of gating for both CD25high and CD127low expression in the isolation of FOXP3-positive cells. This study provides additional insight into the immunological profile of young healthy individuals and uraemic patients as well as in-depth analysis of flow-cytometric gating strategies for Treg isolation, supporting the development of Treg therapy using cells from healthy donors and uraemic patients.

Prognostic model for total mortality in patients with haemodialysis from the Assessments of Survival and Cardiovascular Events (AURORA) study.

OBJECTIVES: Risk factors of mortality in patients with haemodialysis (HD) have been identified in several studies, but few prognostic models have been developed with assessments of calibration and discrimination abilities. We used the database of the Assessment of Survival and Cardiovascular Events study to develop a prognostic model of mortality over 3-4 years. METHODS: Five factors (age, albumin, C-reactive protein, history of cardiovascular disease and diabetes) were selected from experience and forced into the regression equation. In a 67% random try-out sample of patients, no further factors amongst 24 candidates added significance (P < 0.01) to mortality outcome as assessed by Cox regression modelling, and individual probabilities of death were estimated in the try-out and test samples. Calibration was explored by calculating the prognostic index with regression coefficients from the try-out sample to patients in the 33% test sample. Discrimination was assessed by receiver operating characteristic (ROC) areas. RESULTS: The strongest prognostic factor in the try-out sample was age, with small differences between the other four factors. Calibration in the test sample was good when the calculated number of deaths was multiplied by a constant of 1.33. The five-factor model discriminated reasonably well between deceased and surviving patients in both the try-out and test samples with an ROC area of about 0.73. CONCLUSIONS: A model consisting of five factors can be used to estimate and stratify the probability of death for individuals The model is most useful for long-term prognosis in an HD population with survival prospects of more than 1 year.

NT-proBNP and stem cell factor plasma concentrations are independently associated with cardiovascular outcomes in end-stage renal disease hemodialysis patients.

Aims: End-stage renal disease (ESRD) treated by chronic hemodialysis (HD) is associated with poor cardiovascular (CV) outcomes, with no available evidence-based therapeutics. A multiplexed proteomic approach may identify new pathophysiological pathways associated with CV outcomes, potentially actionable for precision medicine. Methods and results: The AURORA trial was an international, multicentre, randomized, double-blind trial involving 2776 patients undergoing maintenance HD. Rosuvastatin vs. placebo had no significant effect on the composite primary endpoint of death from CV causes, nonfatal myocardial infarction or nonfatal stroke. We first compared CV risk-matched cases and controls (n = 410) to identify novel biomarkers using a multiplex proximity extension immunoassay (276 proteomic biomarkers assessed with OlinkTM). We replicated our findings in 200 unmatched cases and 200 controls. External validation was conducted from a multicentre real-life Danish cohort [Aarhus-Aalborg (AA), n = 331 patients] in which 92 OlinkTM biomarkers were assessed. In AURORA, only N-terminal pro-brain natriuretic peptide (NT-proBNP, positive association) and stem cell factor (SCF) (negative association) were found consistently associated with the trial's primary outcome across exploration and replication phases, independently from the baseline characteristics. Stem cell factor displayed a lower added predictive ability compared with NT-ProBNP. In the AA cohort, in multivariable analyses, BNP was found significantly associated with major CV events, while higher SCF was associated with less frequent CV deaths. Conclusions: Our findings suggest that NT-proBNP and SCF may help identify ESRD patients with respectively high and low CV risk, beyond classical clinical predictors and also point at novel pathways for prevention and treatment.

Gastrointestinal sensitivity to soy and milk proteins in patients with IgA nephropathy.

BACKGROUND: sensitivity to food antigens has been postulated as a contributing factor to the pathogenesis of IgA nephropathy (IgAN). METHODS: in this study we used a recently developed mucosal patch technique to evaluate rectal mucosal sensitivity to soy and cow's milk (CM) proteins in IgAN patients (n = 28) compared to healthy subjects (n = 18). The rectal mucosal production of nitric oxide (NO) and release of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) were measured. Serum samples were analyzed for IgA and IgG antibodies to alpha-lactalbumin, beta-lactoglobulin, casein and soy. RESULTS: 14 of 28 (14/28) patients experienced a rectal mucosal reaction, measured by increased NO and/or MPO levels, upon rectal challenge with soy and/or cow's milk proteins. The levels of IgG antibodies to alpha-lactalbumin, beta-lactoglobulin and casein were significantly higher in CM sensitive as compared with non-sensitive IgAN patients, whereas the mean serum levels of IgA antibodies were similar. No differences were seen in serum levels of IgA or IgG antibodies to soy. CONCLUSION: it is concluded that approximately half of our IgAN patients have a rectal mucosal sensitivity to soy or CM, and that an immune reactivity against antigens may be involved in the pathogenesis of IgAN in this subgroup of patients.

Adherence of Renal Transplant Recipients to Once-daily, Prolonged-Release and Twice-daily, Immediate-release Tacrolimus-based Regimens in a Real-life Setting in Sweden.

BACKGROUND: In this study we investigated medication adherence of kidney transplant patients (KTPs) to an immediate-release tacrolimus (IR-T) regimen and, after conversion, to a prolonged-release tacrolimus (PR-T) regimen in routine clinical practice. METHODS: This was a noninterventional, observational, multicenter Swedish study. We included adult KTPs with stable graft function, remaining on IR-T or converting from IR-T to PR-T. Data were collected at baseline, and months 3, 6, and 12 postbaseline. The primary endpoint was adherence using the Basel Assessment of Adherence to Immunosuppressive Medication Scale (BAASIS). Secondary assessments included tacrolimus dose and trough levels, clinical laboratory parameters (eg, estimated glomerular filtration rate), and adverse drug reactions (ADRs). RESULTS: Overall, 233 KTPs were analyzed (PR-T, n = 175; IR-T, n = 58). Mean change in PR-T dose from baseline (4.8 mg/d) to month 12 was -0.2 mg/d, and for IR-T (4.2 mg/d) was -0.4 mg/d; tacrolimus trough levels remained similar. Overall adherence was similar between baseline and month 12 in both groups (PR-T: 54.4% vs 57.0%, respectively; IR-T: 65.5% vs 69.4%); timing adherence followed a similar pattern. The probability of taking adherence improved between baseline and month 12 (odds ratio, 1.97; P = .0092) in the PR-T group only. Mean BAASIS visual analog scale score at baseline was 94.3 ± 11.1% (PR-T) and 95.3 ± 7.6% (IR-T), and >95% at subsequent visits. Laboratory parameters remained stable. Eight (4.6%) patients receiving PR-T (none receiving IR-T) had ADRs considered probably/possibly treatment-related. CONCLUSION: Disparity existed between high, patient-perceived and low, actual adherence. Overall adherence to the immunosuppressive regimen (measured by BAASIS) did not improve significantly over 12 months in stable KTPs converting to PR-T or remaining on IR-T; renal function remained stable.

Kidney function and discrimination of cardiovascular risk in middle-aged men.

OBJECTIVE: To define the optimal glomerular filtration rate (GFR) cut off for discriminating the risk of myocardial infarction or cardiovascular death. DESIGN: Prospective longitudinal observational study. SETTING: A community-based cohort. PARTICIPANTS: A total of 2176 nondiabetic 50-year-old men without cardiovascular disease. METHODS: The men were followed until age 70. GFR was estimated at baseline using the Cockcroft-Gault formula. The optimal GFR cut-off points for discriminating risk of a fatal or nonfatal myocardial infarction and cardiovascular death were defined as the GFR levels maximizing integrated discrimination improvement (IDI). MAIN OUTCOME MEASURES: Fatal or nonfatal myocardial infarction, cardiovascular death. RESULTS: During follow-up, 264 men experienced a fatal or nonfatal myocardial infarction, and 218 died of cardiovascular disease. The IDI-defined optimal GFR cut offs in this study were 98 mL min(-1) for discriminating myocardial infarction risk and 92 mL min(-1) for discriminating risk of cardiovascular death. In Cox proportional hazard models adjusting for established risk factors, the myocardial infarction risk was substantially higher in men with GFR below versus above 98 mL min(-1) [hazard ratio (HR) 1.7, 95% confidence interval (CI) 1.3-2.3, P < 0.001], and the risk of cardiovascular death was doubled in men with GFR below versus above 92 mL min(-1) (HR 2.1, 95% CI 1.5-3.0, P < 0.001). CONCLUSION: The GFR cut-off point for optimal discrimination of cardiovascular risk in the general population may be higher than previously suggested.

Telomere attrition is associated with inflammation, low fetuin-A levels and high mortality in prevalent haemodialysis patients.

INTRODUCTION: Chronic kidney disease (CKD) predisposes to a 10- to 20-fold increased cardiovascular risk. Patients undergo accelerated atherogenesis and vascular ageing. We investigated whether telomere attrition, a marker of cell senescence, contributes to this increased mortality risk. METHODS: This is a cross-sectional study in prevalent haemodialysis patients [n = 175; 98 Males; median (range) age: 66 (23-86) years]. Biochemical markers of oxidative stress and inflammatory status were measured in relation to the patient's leucocyte telomere length. Overall mortality was assessed after a median of 31 (range 2-42) months. RESULTS: Telomere length was shorter in CKD men, despite women being older (average +/- SD 6.41 +/- 1.23 vs. 6.96 +/- 1.48 kb, P = 0.002). Telomere length was associated with age (rho = -0.18, P = 0.01), fetuin-A (rho = 0.26, P = 0.0004), high-sensitivity C-reactive protein (rho = -0.21, P = 0.005) and IL-6 (rho = -0.17, P = 0.02). In a multivariate logistic regression (pseudo r(2) = 0.14), telomere length was associated with age >65 years (odds ratio: 2.11; 95% CI: 1.10, 4.06), sex (2.01; 1.05, 3.86), fetuin-A (1.85; 0.97, 3.50) and white blood cell count (2.04; 1.02, 4.09). Receiver operating characteristic curves identified a telomere length < 6.28 kb as a fair predictor of mortality. Finally, reduced telomere length was associated with increased mortality, independently of age, gender and inflammation (likelihood ratio 41.6, P < 0.0001), but dependently on fetuin-A levels. CONCLUSION: Age and male gender seem to be important contributors to reduced telomere length in CKD patients, possibly via persistent inflammation. Reduced telomere length also contributes to the mortality risk of these patients through pathways that could involve circulating levels of fetuin-A.

Adherence of Renal Transplant Recipients to Once-daily, Prolonged-Release and Twice-daily, Immediate-release Tacrolimus-based Regimens in a Real-life Setting in Sweden.

BACKGROUND: In this study we investigated medication adherence of kidney transplant patients (KTPs) to an immediate-release tacrolimus (IR-T) regimen and, after conversion, to a prolonged-release tacrolimus (PR-T) regimen in routine clinical practice. METHODS: This was a non-interventional, observational, multicenter Swedish study. We included adult KTPs with stable graft function, remaining on IR-T or converting from IR-T to PR-T. Data were collected at baseline, and months 3, 6, and 12 post-baseline. The primary endpoint was adherence using the Basel Assessment of Adherence to Immunosuppressive Medication Scale (BAASIS©). Secondary assessments included tacrolimus dose and trough levels, clinical laboratory parameters (eg, estimated glomerular filtration rate), and adverse drug reactions (ADRs). RESULTS: Overall, data from 233 KTPs were analyzed (PR-T, n = 175; IR-T, n = 58). Mean change in PR-T dose from baseline (4.8 mg/d) to month 12 was -0.2 mg/d, and for IR-T (4.2 mg/d) was -0.4 mg/d; tacrolimus trough levels remained similar. Overall adherence was similar between baseline and month 12 in both groups (PR-T: 54.4% vs 57.0%, respectively; IR-T: 65.5% vs 69.4%); timing adherence followed a similar pattern. The probability of taking adherence improved between baseline and month 12 (odds ratio, 1.97; P = .0092) in the PR-T group only. Mean BAASIS visual analog scale score at baseline was 94.3 ± 11.1% (PR-T) and 95.3 ± 7.6% (IR-T), and >95% at subsequent visits. Laboratory parameters remained stable. Eight (4.6%) patients receiving PR-T (none receiving IR-T) had ADRs considered probably/possibly treatment-related. CONCLUSION: Disparity existed between high, patient-perceived and low, actual adherence. Overall adherence to the immunosuppressive regimen (measured by BAASIS) did not improve significantly over 12 months in stable KTPs converting to PR-T or remaining on IR-T; renal function remained stable.

Tolerance induction ameliorates allograft vasculopathy in rat aortic transplants. Influence of Fas-mediated apoptosis.

Based on successful induction of donor-specific unresponsiveness by alloantigenic stimulation in several animal models of acute rejection, we hypothesized that similar immune manipulations would also inhibit the evolution of chronic rejection and transplant vasculopathy. To induce immune tolerance, DA rats received a PVG heart allograft and were immunosuppressed with cyclosporine for 30 d. At day 100 the animals were challenged with a PVG aortic allograft after either 1 or 18 h of cold ischemia. 8 wk after the aortic transplantation, the grafts were investigated for morphological changes, infiltrating cells, apoptosis, and Fas-Fas ligand expression. Control allografts showed advanced transplant arteriosclerosis, whereas tolerance-induced aortic allografts displayed reduced neointimal formation, less medial atrophy, fewer apoptotic cells, and fewer Fas- and FasL-expressing cells. Prolonged ischemic storage time did not profoundly alter the morphological changes of the allografts. Fas expression was found in T cells, macrophages, vascular smooth muscle cells, and endothelial cells, whereas FasL was expressed mainly by T cells and macrophages. FasL mRNA expression was evident throughout the entire allograft wall. In conclusion, induction of allospecific tolerance can effectively prevent transplant arteriosclerosis. Cold ischemia damage does not abrogate the beneficial effect of tolerance, but creates a separate identity of mainly endothelial lesions. Furthermore, Fas-mediated apoptosis appears to be involved in the pathological lesions seen in chronic rejection.

Platelet-derived endothelial cell growth factor. Pharmacokinetics, organ distribution and degradation after intravenous administration in rats.

Platelet-derived endothelial cell growth factor (PD-ECGF) stimulates chemotaxis of endothelial cells in vitro and has angiogenic activity in vivo. Recently PD-ECGF was shown to have thymidine phosphorylase activity. In order to study possible therapeutic applications of PD-ECGF we used a rat model to determine its pharmacokinetics and tissue distribution after intravenous injection. [125I]PD-ECGF disappeared from the plasma in a biphasic manner, with estimated distribution and elimination half-lives of 17 min and 7 h, respectively. PD-ECGF was metabolized in the liver, excreted via the bile, and not accumulated in any organ system. The stability and long half-life in the circulation, together with the specificity for endothelial cells, suggest that PD-ECGF may be useful as a therapeutic agent to stimulate re-endothelialization in vivo, or, in view of its thymidine phosphorylase activity, in chemotherapy, by decreasing the pool of available thymidine.

Impact and management of hyperlipidemia posttransplantation.

CVD morbidity and mortality is a major cause of premature death and allograft loss in recipients of renal and cardiac transplants, and hyperlipidemia--a major risk factor for CVD in the general population--may be a significant risk factor for CVD in transplant recipients. Hyperlipidemia is common after transplantation, and immunosuppression with corticosteroids, cyclosporine, or sirolimus causes posttransplantation hyperlipidemia. Posttransplantation hyperlipidemia can be treated in various ways, but statin therapy has thus far proved to be the most effective in lowering lipid levels in the transplant population. However, to date, no large solid end-point studies have demonstrated that lipid-lowering therapy with statins (or any other class of agents) significantly reduces CVD morbidity or mortality and improves allograft survival in transplant recipients, although some smaller studies point in that direction. The ongoing ALERT trial is currently studying whether early and later intervention with a statin (fluvastatin) can reduce chronic allograft dysfunction, decrease CVD, and improve patient survival in transplant recipients.

Increased fracture rate in diabetes mellitus and females after renal transplantation.

BACKGROUND: Bone disease and fractures after organ transplantation pose severe clinical problems. About 20% of renal transplant patients have type 1 diabetes (IDDM). However, data are scarce in the literature about the occurrence of spontaneous fractures in IDDM patients posttransplantation. METHODS: In this cross-sectional study using a questionnaire and hospital records the prevalence of symptomatic bone disease was investigated in 193 renal transplanted patients with functioning renal grafts 6 months to 23 years after the transplantation. RESULTS: The frequency of IDDM was 18%. In the total group the rate of osteoporotic fractures posttransplantation was 17%, and the majority of fractures occurred within the first 3 years after the transplantation. A high rate of fractures, 40%, was noted in the diabetes group (P<0.001), compared with 11% in the nondiabetes group. Fractures seen in IDDM were often multiple and located mostly in the appendicular skeleton, i.e., in ankles and feet. Female gender was also associated with an elevated fracture rate, 23% (P<0.05). CONCLUSION: An increased incidence of osteoporotic fractures after renal transplantation was found in diabetic and female patients. The mechanism behind bone fragility in IDDM is multifactorial and despite a restored renal function bone disease may progress, and is probably enhanced by the immunosuppressive treatment.

Inhibition of transplant arteriosclerosis in rat aortic grafts by low molecular weight heparin derivatives.

The effects of low molecular weight heparin derivatives with a low anticoagulant activity on transplant arteriosclerosis (TA) in a rat aortic transplant model were investigated. TA was induced by ischemia in the syngeneic transplants and primarily by immunological mechanisms in the allogeneic transplants. Treatment with the heparin derivatives, OAM 71262 or LA-heparin, was administered in a dosage of 250 micrograms/kg/hr by mini-osmotic pumps during 8 weeks. No immunosuppressive regimen was given to the recipient rats in either model. All rats were killed 8 weeks after aortic grafting. The grafts were examined for intimal and medial changes using an image analysis system. Heparin derivatives had a beneficial effect on both the intimal thickening and the medial injury in the syngeneic transplants, but not in the allogeneic grafts. In the syngeneic LA-heparin treated grafts, the thickness of the intima was less than that in the syngeneic control grafts (P < 0.05). In the syngeneic transplants, a significant increase was observed in the media after treatment with OAM 71262 (P < 0.01) as well as those with LA-heparin (P < 0.001). In the syngeneic grafts treated with both heparin derivatives, a significant reduction in the antigen expression of alpha-actin-containing smooth muscle cells in the intima, transforming growth factor-beta 1 both in the media and adventitia, and platelet-derived growth factor-beta receptors in the adventitia was observed immunohistochemically. In summary, low molecular weight heparin derivatives with low anticoagulant activity partially inhibited ischemia-induced syngeneic TA, whereas no such effect could be demonstrated in nonimmunosuppressed recipients with allogeneic grafts.

Smooth muscle cell migration into intima and adventitia during development of transplant vasculopathy.

Smooth muscle cell (SMC) migration from the medial layer into the intima is a characteristic feature of transplant vasculopathy and is thought to be regulated by locally produced cytokines. We studied the expression of smooth muscle alpha-actin, PDGF B-ligand and, PDGF alpha- and beta-receptors in rat aortic allografts with transplant vasculopathy using immunohistochemistry. At two weeks, an intense expression of PDGF B-ligand and, PDGF alpha- and beta-receptors was found in the neointima and adventitia. Medial SMC expression decreased with time in parallel with accumulation of smooth muscle alpha-actin in the neointima and adventitia. PDGF expression persisted in the adventitia. Prolonged ischemic storage time resulted in an increase in the number of alpha-actin-positive SMCs in the intima of syngeneic grafts. These data indicate that SMCs migrate into both the intima and adventitia. This migration may be induced, at least in part, by PDGF produced by graft invading monocyte-derived macrophages.

The localization of hyaluronan in normal and rejected human kidneys.

Hyaluronan (HYA) is a large glycosaminoglycan with a high capacity to immobilize water. Increased levels of HYA have previously been observed in plasma as well as in affected tissues in various inflammatory conditions. The morphological localization of HYA has, however, not been described in normal or rejected human kidneys. Using a recently developed method for localization of HYA in tissue sections by means of a biotin-labeled hyaluronan binding protein used as a probe, we have now investigated the distribution of HYA in normal and irreversibly rejected human kidneys. In the normal kidney HYA was essentially confined to the medulla. In the rejected kidneys increased amounts of HYA were observed primarily in the cortex and in sclerotic vessels. Incubating tissue sections with hyaluronidase abolished the staining for HYA, showing the specificity of the staining procedure. The increased amounts of HYA of the rejected kidney may play a role in local edema formation, and thereby alter graft function.

Candesartan cilexetil reduces graft arteriosclerosis in aortic transplantation model in rat.

To date established treatment of transplant arteriosclerosis is basically missing and there is a need for new therapeutic approaches. Angiotensin II (Ang II) and Ang II receptor type 1 (AT) are present in the vascular wall. Blocking of the AT1 receptor by pharmacological agents may inhibit damaging effects of Ang II on endothelial and smooth muscle cells. The purpose of the study was to evaluate the effect of the AT1 receptor blocker Candesartan cilexetil on the development of graft arteriosclerosis in a rat aortic transplant model. Two strain combinations were used for aortic transplantation: DA to PVG; and PVG to PVG. The animals received Candesartan cilexetil treatment (9.5 + 1.4 mg/kg/day) for 8 weeks. Candesartan cilexetil treatment reduced neointimal formation both in allografts (Qint 30.2 +/- 8.8% vs. 22.1 +/- 8.7%, P < 0.05) and in isografts (Qint 15.5 +/- 4.4% vs. 6.7 +/- 3.3%, P = 0.0001). Blocking of the AT1 receptor signalling by Candesartan cilexetil was also associated with a reduced expression of TGF-beta1. Macrophage infiltration was not affected by the treatment. Candesartan cilexetil treatment leads to reduced neointimal formation in aortic transplant. The positive effect of the drug might be partly explained by a reduction of TGF-beta1 expression in the grafts. Candesartan treatment may provide another possibility for prevention of transplant arteriosclerosis and chronic rejection.

Increased immunoreactivity of transforming growth factor-beta in human kidney transplants.

Transforming growth factor-beta (TGF-beta) has been known to be involved in the pathogenesis of various kidney diseases. TGF-beta is also a potent immunosuppressor that has been shown to be induced after allogeneic transplantation. We have studied the distribution of immunoreactive TGF-beta proteins in different compartments of 21 allogeneic transplanted kidneys that had been rejected through acute (eight interstitial or six vascular) and chronic (seven vascular) processes. This distribution was compared with that in seven non-rejected transplanted and five non-transplanted kidneys with intact morphology. There were no obvious differences between the three groups of rejected grafts and the transplanted non-rejected group for the expression of TGF-beta s. A major difference was seen between transplanted kidneys, which exhibited clearly positive TGF-beta and LTBP1 (latent TGF-beta binding protein) immunoreactivities, and the non-transplanted kidneys. The non-transplanted kidneys showed only very weak or no immunoreactivity for these proteins. The morphologically intact non-rejected grafts showed a significantly increased immunoreactivity compared with the non-transplanted kidneys. When the transplanted kidneys were classified into two groups (i.e. with or without diabetes mellitus) and compared with regard to the expression of all TGF-beta s, no difference was found. Thus, transplantation was the most important predictor for expression of TGF-beta s and LTBP1, and the largest expression increase in the allografts occurred in the interstitium, followed by the glomeruli and blood vessels. Tubuli and lymphocyte aggregates stained only faintly. The results imply that TGF-beta is induced rapidly after kidney transplantation. This induction can suppress immunoreactivation, but concomitantly promotes changes such as arteriosclerosis and fibrosis associated with rejection.

Expression of CD11b and ICAM-1 in an in vivo model of transplant arteriosclerosis.

Adhesion molecules play a crucial role in transplant rejection in regulating the interaction of inflammatory cells with cells in the vascular wall. In an aortic transplantation model, we have previously analysed the early adhesion process (7.5 min to 24 h) and the impact of cold ischaemia time (1-24 h) upon transplant arteriosclerosis during the first 2 months after transplantation in the rat. The aim of this investigation was to study adhesion molecules in accelerated transplant arteriosclerosis in a rat model by analysing the immunohistochemical expression of CD11b and ICAM-1 up to 2 months and followed by a semiquantitative evaluation and multivariant analysis. Antigen expression of CD11b and ICAM-1 adhesion molecules was stronger in the aortic allografts than in the ischaemia-induced syngeneic aortic grafts in the whole vessel wall. Neither ICAM-1 nor CD11b antigen expression correlated significantly with time periods of ischaemia/reperfusion injury in allogeneic or syngeneic aortic transplants. CD11b and ICAM-1 are induced by allogeneic stimuli in transplanted aortas suggesting a role in the pathogenesis of transplant arteriosclerosis. Our findings have implications for understanding the role of cell adhesion activation in the vascular wall subject to chronic graft rejection.

Risk factors for and management of post-transplantation cardiovascular disease.

The mortality rates due to cardiovascular disease (CVD) in transplant recipients are greater than in the general population. CVD is a major cause of both graft loss and patient death in renal transplant recipients, and improving cardiovascular health in transplant recipients will presumably help to extend both patient and graft survival. Further studies are needed to better evaluate the effectiveness of risk modification on subsequent CVD morbidity and mortality. There is no reason to consider risk factors for CVD such as hyperlipidaemia, hypertension and diabetes mellitus in transplant recipients differently from in the general population. In addition, there are specific transplantation risk factors such as acute rejection episodes and the use of immunosuppressive drugs. It is obvious that several of the immunosuppressive agents used today have disadvantageous influences on risk factors for CVD such as hyperlipidaemia, hypertension and post-transplantation diabetes mellitus (PTDM), but the relative importance of immunosuppressant-induced increases in these risk factors is basically unknown. This may be a strong argument for the selective use and individual tailoring of immunosuppressive agents based upon the risk factor profile of the patient, without jeopardising the function of the graft. Hyperlipidaemia is common after transplantation, and immunosuppression with corticosteroids, cyclosporin, or sirolimus (rapamycin) causes different types of post-transplantation hyperlipidaemia. However, to date, no studies have demonstrated that lipid lowering strategies significantly reduce CVD morbidity or mortality and improve allograft survival in transplant recipients. Several studies using preventive or interventional approaches are ongoing and will be reported in the near future. Post-transplantation hypertension appears to be a major risk factor determining graft and patient survival, and immunosuppressive agents have different effects on hypertension. Controlled studies support the opinion that post-transplantation hypertension must be treated as strictly as in a population with essential hypertension, diabetes mellitus, or chronic renal failure. As increasing numbers of immunosuppressive agents become available for use, we may be in a better position to tailor immunosuppressive therapy to the individual patient, avoiding the use of diabetogenic drugs, drug combinations, or inappropriate doses in patients susceptible to PTDM. Multiple acute rejection episodes have also been demonstrated to be a risk factor for CVD - a strong argument for the use of immunosuppressive drugs to reduce acute rejection. Until we have a better understanding from ongoing landmark studies on the management of CVD, presently available therapy to reduce risk factors needs to be used together with individual tailoring of immunosuppressive therapy with the aim of reducing CVD in these patients.