CRTC2 polymorphism as a risk factor for the incidence of metabolic syndrome in patients with solid organ transplantation.

Metabolic syndrome after transplantation is a major concern following solid organ transplantation (SOT). The CREB-regulated transcription co-activator 2 (CRTC2) regulates glucose metabolism. The effect of CRTC2 polymorphisms on new-onset diabetes after transplantation (NODAT) was investigated in a discovery sample of SOT recipients (n1=197). Positive results were tested for replication in two samples from the Swiss Transplant Cohort Study (STCS, n2=1294 and n3=759). Obesity and other metabolic traits were also tested. Associations with metabolic traits in population-based samples (n4=46'186, n5=123'865, n6>100,000) were finally analyzed. In the discovery sample, CRTC2 rs8450-AA genotype was associated with NODAT, fasting blood glucose and body mass index (Pcorrected<0.05). CRTC2 rs8450-AA genotype was associated with NODAT in the second STCS replication sample (odd ratio (OR)=2.01, P=0.04). In the combined STCS replication samples, the effect of rs8450-AA genotype on NODAT was observed in patients having received SOT from a deceased donor and treated with tacrolimus (n=395, OR=2.08, P=0.02) and in non-kidney transplant recipients (OR=2.09, P=0.02). Moreover, rs8450-AA genotype was associated with overweight or obesity (n=1215, OR=1.56, P=0.02), new-onset hyperlipidemia (n=1007, OR=1.76, P=0.007), and lower high-density lipoprotein-cholesterol (n=1214, ß=-0.08, P=0.001). In the population-based samples, a proxy of rs8450G>A was significantly associated with several metabolic abnormalities. CRTC2 rs8450G>A appears to have an important role in the high prevalence of metabolic traits observed in patients with SOT. A weak association with metabolic traits was also observed in the population-based samples.

Efficacy and safety of sirolimus and everolimus in heart transplant patients: a retrospective analysis.

BACKGROUND: Since its introduction as an immunosuppressant in the late 1990s, sirolimus (SRL) has been used to prevent rejections after heart transplantation (HTx) in the United States. An analogue, everolimus (ERL) has been mainly used in Europe. We performed a retrospective longitudinal single-center study to evaluate efficacy and side effects of SRL and ERL. PATIENTS AND METHODS: We analyzed 71 patients, 39 in the SRL and 32 in the ERL group. The following data were collected: Trough levels of SRL and ERL, biopsy-proven rejections, renal function, blood lipids, hematology, blood pressure, pulse rate, and side effects (via an anonymous questionnaire). Follow-up time was 6 months. No prisoners or organs from prisoners were used in the study. RESULTS: Introduction of SRL or ERL into therapy took place 44 or 42 months (average) after HTx. SRL and ERL were equally effective in preventing rejection (8/39 versus 6/32). Hemoglobin levels decreased slightly in the SRL group (nonsignificant). Leucocytes and thrombocyte levels decreased in both groups (P < .05 only in the ERL group). Creatinine levels remained unchanged. Cholesterol and triglyceride levels increased significantly in the SRL group. High-density lipoprotein levels increased significantly in the ERL group. Vital signs remained stable in both groups. Side effects (mainly edema, gastrointestinal symptoms and infections) were considerable and prompted discontinuation in 39% of all patients in both groups. Infections were more frequent in SRL (18/39 versus 12/32, nonsignificant). Calcineurin therapy could be reduced by 25% in SRL and 45% in ERL. CONCLUSION: The impact of SRL and ERL on laboratory values and rejection rates, as well as on clinical parameters, is similar with a slight advantage to ERL regarding lipids and rate of infections (not significant). Both SRL and ERL allow an important reduction of calcineurin-therapy; however, both drugs have considerable side effects, which often require discontinuation of therapy.

Proliferation signal inhibitors and post-transplant malignancies in heart transplantation: practical clinical management questions.

Although malignancy is a major threat to long-term survival of heart transplant (HT) recipients, clear strategies to manage immunosuppression in these patients are lacking. Several lines of evidences support the hypothesis of an anticancer effect of proliferation signal inhibitors (PSIs: mammalian target of rapamycin [mTOR] inhibitors) in HT recipients. This property may arise from PSI's ability to replace immunosuppressive therapies that promote cancer progression, such as calcineurin inhibitors or azathioprine, and/or through their direct biological actions in preventing tumor development and progression. Given the lack of randomized studies specifically exploring these issues in the transplant setting, a collaborative group reviewed current literature and personal clinical experience to reach a consensus aimed to provide practical guidance for the clinical conduct in HT recipients with malignancy, or at high risk of malignancy, with a special focus on advice relevant to potential role of PSIs.

Recurrent non-melanoma skin cancer: remission of field cancerization after conversion from calcineurin inhibitor- to proliferation signal inhibitor-based immunosuppression in a cardiac transplant recipient.

Non-melanoma skin cancers (NMSCs) are the most common malignancies after solid organ transplantation. Their incidence increases with time after transplantation. Calcineurin-inhibitors (CNIs) and azathioprine are known as skin neoplasia-initiating and -enhancing immunosuppressants. In contrast, increasing clinical experience suggests a relevant antiproliferative effect of mammalian target of rapamycin inhibitors, also named proliferation signal inhibitors (PSIs). We report the case of a cardiac allograft recipient with an impressive and consolidated reduction of recurrent NMSC, observed after conversion from CNI-therapy to a PSI-based protocol.

Eotaxin/CCL11 levels correlate with myocardial fibrosis and mast cell density in native and transplanted rat hearts.

INTRODUCTION: Myocardial fibrosis contributes to hemodynamic and cardiac functional alterations commonly observed posttransplantation. Cardiac mast cells (MC) have been linked to fibrosis in posttransplantation hearts. Eotaxin, which has been shown to be involved in fibrogenesis, has been demonstrated to be increased in production in cardiac macrophages. The aim of our study was to correlate myocardial fibrosis during heart transplant rejection in the rat with eotaxin/chemokine [c-c motif] ligand 11 (CCL11) expression, and with various subtypes of infiltrating cardiac MC, namely connective-type MC (CTMC) and mucosa-type MC (MMC). METHODS: We used tissues from 2 previous studies of ongoing acute rejection in allogeneic Brown-Norway to Lewis rat and an isogeneic Brown-Norway to Brown-Norway heterotopic heart transplantation models under cyclosporin/prednisolone immunosuppression. Collagen fibrils were stained with Masson's trichrome with myocardial fibrosis expressed as percent fibrotic area per total section area. Eotaxin/CCL11 previously measured in heart tissue using enzyme-linked immunosorbent assay (ELISA) was correlated with the extent of myocardial fibrosis. We compared values from native hearts (n = 4) as well as transplants on days 5, 16, and 28 (n = 4 in each group). RESULTS: The area of myocardial fibrosis was significantly increased in the allogeneic compared with the isogeneic group at day 16 (38% vs 21%) and at day 28 (49% vs 22%) after transplantation. Myocardial fibrosis correlated significantly with eotaxin/CCL11 concentrations and the density of MMC, but not with CTMC in heart tissue. CONCLUSIONS: Eotaxin-triggered MC infiltration of the heart may contribute to myocardial fibrosis after transplantation. Targeting eotaxin/CCL11 with monoclonal antibodies, such as bertilimumab, could reduce MC infiltration, possibly resulting in decreased myocardial fibrosis and improved contractile function after heart transplantation.

Diastolic dysfunction of the cardiac allograft and maximal exercise capacity.

BACKGROUND: Peak oxygen uptake (peak Vo(2)) is an established integrative measurement of maximal exercise capacity in cardiovascular disease. After heart transplantation (HTx) peak Vo(2) remains reduced despite normal systolic left ventricular function, which highlights the relevance of diastolic function. In this study we aim to characterize the predictive significance of cardiac allograft diastolic function for peak Vo(2). METHODS: Peak Vo(2) was measured using a ramp protocol on a bicycle ergometer. Left ventricular (LV) diastolic function was assessed with tissue Doppler imaging sizing the velocity of the early (Ea) and late (Aa) apical movement of the mitral annulus, and conventional Doppler measuring early (E) and late (A) diastolic transmitral flow propagation. Correlation coefficients were calculated and linear regression models fitted. RESULTS: The post-transplant time interval of the 39 HTxs ranged from 0.4 to 20.1 years. The mean age of the recipients was 55 +/- 14 years and body mass index (BMI) was 25.4 +/- 3.9 kg/m(2). Mean LV ejection fraction was 62 +/- 4%, mean LV mass index 108 +/- 22 g/m(2) and mean peak Vo(2) 20.1 +/- 6.3 ml/kg/min. Peak Vo(2) was reduced in patients with more severe diastolic dysfunction (pseudonormal or restrictive transmitral inflow pattern), or when E/Ea was > or =10. Peak Vo(2) correlated with recipient age (r = -0.643, p < 0.001), peak heart rate (r = 0.616, p < 0.001) and BMI (r = -0.417, p = 0.008). Of all echocardiographic measurements, Ea (r = 0.561, p < 0.001) and Ea/Aa (r = 0.495, p = 0.002) correlated best. Multivariate analysis identified age, heart rate, BMI and Ea/Aa as independent predictors of peak Vo(2). CONCLUSIONS: Diastolic dysfunction is relevant for the limitation of maximal exercise capacity after HTx.

Cytokine activation and disease progression in patients with stable moderate chronic heart failure.

BACKGROUND: Activation of the cytokine and the complement system is associated with disease progression in severe congestive heart failure (CHF). Magnitude and prognostic relevance of cytokine and complement activation remain uncertain in patients with moderate CHF. OBJECTIVES: Measurement of cytokine and complement activation in patients with moderate CHF and testing whether C-reactive protein (CRP) can serve as a surrogate marker of their activation, adding independent prognostic information when co-measured with B-type natriuretic peptide (BNP). METHODS: The 118 study participants were separated into three groups based on pre-determined CRP and BNP levels: Group I (n = 27; CRP > 5 mg/liter, BNP > or = 200 pg/ml); Group II (n = 46; CRP < or = 5 mg/liter, BNP > or = 200 pg/ml); and Group III (n = 45; CRP < or = 5 mg/liter, BNP < 200 pg/ml). RESULTS: Mortality was high in Group I (30%; log-rank p < 0.001) but low in Groups II and III (2% and 4%, respectively; log rank, p = 0.7). No differences were observed for left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD) between Groups I and II (31 +/- 16 vs 32 +/- 14% and 66 +/- 16 vs 65 +/- 11 mm, respectively), whereas in Group III LVEF was higher (42 +/- 17%, p = 0.002) with smaller LVEDD (57 +/- 13 mm, p = 0.012). Cytokine sCD14 and tumor necrosis factor (TNF)-alpha levels were not different between the three groups. However, interleukin-6 levels (9.75 +/- 8.17 pg/ml, p = 0.001) and the terminal complement complex C5b-9 (109.9 +/- 68 ng/ml; p = 0.04) were elevated in Group I, both correlating with CRP (interleukin-6: r = 0.5, p < 0.001; C5b-9: r = 0.41, p = 0.001). CONCLUSIONS: CRP may be used as a surrogate parameter for interleukin-6 and complement activation in moderate CHF. CRP in combination with BNP identifies a high-risk group with a tendency for poor outcome not discriminated by cardiac function.

Diastolic dysfunction in human cardiac allografts is related with reduced SERCA2a gene expression.

Previous studies demonstrated that impaired left ventricular (LV) relaxation in cardiac allografts limits exercise tolerance post-transplant despite preserved systolic ejection fraction (EF). This study tested in human cardiac allografts whether the isovolumic relaxation time (IVRT), which provides the basis for most of diastolic LV filling, relates with gene expression of regulatory proteins of calcium homeostasis or cardiac matrix proteins. Gene expression was studied in 31 heart transplant recipients (25 male, 6 female) 13-83 months post-transplant with LVEF >50%, LV end-diastolic pressure <20 mmHg, normal LV mass index and without allograft rejection or significant cardiac pathology. IVRT related with the other diastolic parameters e-wave velocity (r = -0.46; p = 0.01), e/a-wave ratio (r = -0.5; p < 0.01) but not with heart frequency (r = -0.16; p = 0.4). No relation of IVRT was observed for immunosuppression, mean rejection grade or other medication. IVRT was not related with gene expression of desmin, collagen I, phospholamban, the Na+-Ca2+ exchanger, the ryanodine receptor or interstitial fibrosis but correlated inversely with SERCA2a (r = -0.48; p = 0.02). Prolonged IVRT is associated with decreased SERCA2a expression in cardiac allografts without significant other pathology. Similar observations in non-transplanted patients with diastolic failure suggest that decreased SERCA2a expression is an important common pathomechanism.

How well can anaesthetists discriminate pulse oximeter tones?

The ability of experienced anaesthetists to discern oxygen saturation by listening to the tones of a Datex AS3 pulse oximeter was examined. Five-second samples were recorded using a high fidelity patient simulator and replayed singly and in pairs. Whilst the lower saturations were generally recognized as lower, the perceived range was greatly compressed. Median perceived estimates for 70% saturation was 89%, for 80% was 93% and for 94% was 94%. When comparing pairs of samples, the direction of the difference was correctly discerned by 70% of anaesthetists for differences of 2%, rising to 95% for differences of greater than 8% oxygen saturation. The magnitude of the difference was consistently underestimated. With an actual difference of 20%, the median estimate was 5%. The results indicate that while qualitative estimate changes in oxygen saturation are moderately reliable, quantitative estimation is severely limited by a compromised perceived scale. This may lead to underestimation of the severity if the auditory signal is relied on in isolation. A non-linear (musical) scale may prove more appropriate and should be investigated. Testing experienced anaesthetists demonstrated that most could detect the direction, but not the magnitude of a change in saturation by listening to the change in pitch of a Datex AS3 pulse oximeter tone.

[Indication, management and problems of cardiac transplantation]. / Herztransplantation--Indikation, Vorgehen, Chancen und Probleme.

Cardiac transplantation (HTx) remains one of the most important options for the management of end stage heart failure which is treated with optimal medical therapy. Evolving surgical techniques (implantable cardioverter-defibrillator (ICD), cardiac resynchronization therapy (CRT)) and mechanical device-therapie (ventricular assist devices (VAD)) and medical therapies have yielded incremental improvements in outcomes. These alternatives to HTx, however, usually only postpone the occurrence of the final end stage situation. This explains why HTx remains the last option for a substantial number of especially younger severe heart failure patients with upcoming renal failure. It is very recommendable to refer such kind of patients to university-based and specialized advanced heart failure and cardiac transplant centers, in time. This allows the introduction of optimal medical therapy, the careful medical and psychological evaluation and preparation of the considered HTx, as well as the full information procedure which has to be delivered to HTx candidates. HTx candidates should be aware about outcome numbers, medication toxicities, complications of immunosuppression, as well as the ever-present threat of cardiac allograft vasculopathy, infections and neoplasias after HTx.

Solid organ transplantation across the ABO histo-blood group barrier: a case report.

The ABO blood group system until recently constituted an insuperable barrier for solid organ transplantation, but cases of heart transplantation in infants and kidney transplantation in adults have been reported, wherein ABO-incompatible grafts have been successful. In 1990, the molecular genetic basis of three major alleles at the ABO locus was elucidated; A and B glycosyltransferases are specified by a variety of functional alleles at this locus. The antibody response to ABH antigens, namely, naturally occurring anti-A/B IgM and IgG isotype agglutinins, are controlled preoperatively by recipient conditioning using plasma exchange, immunoadsorption, and immunosuppressive regimens. We report an O-type patient who accidentally received a B-type cardiac allograft in 1997 who survived for 5 years, dying for an unrelated reason. Over a period of 45 months semiquantitatively we monitored the expression of ABO-type antigens in graft heart vessels using monoclonal antibodies on sections of formalin-fixed, paraffin-embedded biopsies. We observed a progressive change in the antigenic profile of graft endothelial cells from B- to O-type, which was first detected at 1 year posttransplant and most prominent 3 years later, the end of the observation period. No temporal relationship was observed between the transition from B to O expression, the anti-B antibody levels or the immunosuppressive regimen.

New concepts in organ preservation.

Organ preservation between donor and recipient is an important link in a chain that ultimately should lead to long term survival of the recipient thanks to a well-preserved, functionally intact organ. The period of organ ischaemia outside the body is subject to a number of biochemical stress factors which become known in more detail as knowledge on biochemical and immunological mechanisms improves. Efficacy of preservation fluids hence reduction of ischaemia injury may become enhanced by such additives as ion channel blockers, enzyme inhibitors, haeme oxygenase modulators, endothelin-l-inhibitors, quenchers of free radicals and anti-apoptotic agents. Many of these compounds, albeit of great theoretical interest, have not (yet?) made their way into clinical practice. This contribution is a survey of some promising agents, concentration and physicochemical interactions of which are analysed in some detail.

Successful management of a B-type cardiac allograft into an O-type man with 3(1/2)-year clinical follow-up.

BACKGROUND: In May 1997, a 19-year-old male patient of histo-blood group type O suffering from congenital end-stage heart failure accidentally received a cardiac allograft of type B and is still alive in fair condition. METHODS: In addition to conventional immunosuppressive therapy, plasma exchange (PEX), extracorporeal immunoabsorption (EIA), intravenous immunoglobulins (IVIG), and C1 inhibitor were used. RESULTS: Such treatment successfully reduced both IgM and IgG anti-B levels and complement hyperactivity and allowed to reach the state of accommodation without obvious signs of rejection. The patient has been surviving for 42 months; retransplantation with an O-type heart remained unnecessary. CONCLUSION: Humoral rejection has been avoided in this patient, with PEX, EIA, IVIG, and C1 inhibitor substantially contributing to this success. With future availability of such combined therapies, preferably before transplantation, vascular rejection events caused by preformed antibodies and complement (ABO mismatch or anti-HLA) could be prevented or treated.

Doppler tissue imaging for assessing left ventricular diastolic dysfunction in heart transplant rejection.

OBJECTIVE: To test the hypothesis that diastolic mitral annular motion velocity, as determined by Doppler tissue imaging and left ventricular diastolic flow propagation velocity, is related to the histological degree of heart transplant rejection according to the International Society of Heart and Lung Transplantation (ISHLT). METHODS: In 41 heart transplant recipients undergoing 151 myocardial biopsies, the following Doppler echocardiographic measurements were performed within one hour of biopsy: transmitral and pulmonary vein flow indices; mitral annular motion velocity indices; left ventricular diastolic flow propagation velocity. RESULTS: Late diastolic mitral annular motion velocity (A(DTI)) and mitral annular systolic contraction velocity (SC(DTI)) were higher in patients with ISHLT < IIIA than in those with ISHLT >/= IIIA (A(DTI), 8.8 cm/s v 7.7 cm/s (p = 0.03); SC(DTI), 19.3 cm/s v 9.3 cm/s (p < 0.05)). Sensitivity and specificity of A(DTI) < 8.7 cm/s (the best cut off value) in predicting significant heart transplant rejection were 82% and 53%, respectively. Early diastolic mitral annular motion velocity (E(DTI)) and flow propagation velocity were not related to the histological degree of heart transplant rejection. CONCLUSIONS: Doppler tissue imaging of the mitral annulus is useful in diagnosing heart transplant rejection because a high late diastolic mitral annular motion velocity can reliably exclude severe rejection. However, a reduced late diastolic mitral annular motion velocity cannot predict severe rejection reliably because it is not specific enough.

Effect of carvedilol on survival in severe chronic heart failure.

BACKGROUND: Beta-blocking agents reduce the risk of hospitalization and death in patients with mild-to-moderate heart failure, but little is known about their effects in severe heart failure. METHODS: We evaluated 2289 patients who had symptoms of heart failure at rest or on minimal exertion, who were clinically euvolemic, and who had an ejection fraction of less than 25 percent. In a double-blind fashion, we randomly assigned 1133 patients to placebo and 1156 patients to treatment with carvedilol for a mean period of 10.4 months, during which standard therapy for heart failure was continued. Patients who required intensive care, had marked fluid retention, or were receiving intravenous vasodilators or positive inotropic drugs were excluded. RESULTS: There were 190 deaths in the placebo group and 130 deaths in the carvedilol group. This difference reflected a 35 percent decrease in the risk of death with carvedilol (95 percent confidence interval, 19 to 48 percent; P=0.00013, unadjusted; P=0.0014, adjusted for interim analyses). A total of 507 patients died or were hospitalized in the placebo group, as compared with 425 in the carvedilol group. This difference reflected a 24 percent decrease in the combined risk of death or hospitalization with carvedilol (95 percent confidence interval, 13 to 33 percent; P<0.001). The favorable effects on both end points were seen consistently in all the subgroups we examined, including patients with a history of recent or recurrent cardiac decompensation. Fewer patients in the carvedilol group than in the placebo group withdrew because of adverse effects or for other reasons (P=0.02). CONCLUSIONS: The previously reported benefits of carvedilol with regard to morbidity and mortality in patients with mild-to-moderate heart failure were also apparent in the patients with severe heart failure who were evaluated in this trial.

Low molecular weight dextran sulfate prevents complement activation and delays hyperacute rejection in pig-to-human xenotransplantation models.

Dextran sulfate of 5000 molecular weight (DXS 5000) is known to block complement activation as well as the intrinsic coagulation cascade by potentiation of C inhibitor. The effect of DXS 5000 on hyperacute rejection (HAR) was tested in pig-to-human xenotransplantation models. For in vitro testing, a cytotoxicity assay was used with the pig kidney cell line PK15 as target cells and fresh, undiluted human serum as antibody and complement source. Ex vivo pig lung perfusion was chosen to assess DXS 5000 in a physiologic model. Pig lungs were perfused with fresh, citrate-anticoagulated whole human blood to which 1 or 2 mg/ml DXS 5000 were added; the lungs were ventilated and the blood de-oxygenated. Pulmonary vascular resistance (PVR) and blood oxygenation (deltapO2) were monitored throughout the experiment. Autologous pig blood and human blood without DXS 5000 served as controls. In the PK 15 assay DXS 5000 led to a complete, dose-dependent inhibition of human serum cytotoxicity with an average IC50 of 43 +/- 18 microg/ml (n=8). Pig lungs perfused with untreated human blood (n=2) underwent HAR within 105 +/- 64 min, characterized by increased PVR, decrease of deltapO2, and generalized edema. Microscopically, capillary bleeding as well as deposition of human antibodies, complement and fibrin could be observed. Addition of DXS 5000 (n=4) prolonged lung survival to 170 +/- 14 min for 1 mg/ml and 250 +/- 42 min for 2 mg/ml. and PVR values as well as edema formation were comparable to control lungs that were perfused with autologous pig blood (n=2). Activation of complement (activation products in serum, deposition on lung tissue) and the coagulation system (fibrin monomers) were significantly diminished as compared to human blood without DXS 5000. Binding of anti-Gal antibodies was not influenced, and in vitro experiments showed no evidence of complement depletion by DXS 5000. In conclusion, DXS 5000 is an efficient complement inhibitor in pig-to-human xenotransplantation models and therefore a candidate for complement-inhibitory/anti-inflammatory therapy either alone or in combination with other substances and warrants further investigation.