A novel IgE antibody targeting the prostate-specific antigen as a potential prostate cancer therapy

BACKGROUND

Prostate cancer (PCa) is the second leading cause of cancer deaths in men in the United States. The prostate-specific antigen (PSA), often found at high levels in the serum of PCa patients, has been used as a marker for PCa detection and as a target of immunotherapy. The murine IgG1 monoclonal antibody AR47.47, specific for human PSA, has been shown to enhance antigen presentation by human dendritic cells and induce both CD4 and CD8 T-cell activation when complexed with PSA. In this study, we explored the properties of a novel mouse/human chimeric anti-PSA IgE containing the variable regions of AR47.47 as a potential therapy for PCa. Our goal was to take advantage of the unique properties of IgE in order to trigger immune activation against PCa.

METHODS

Binding characteristics of the antibody were determined by ELISA and flow cytometry. In vitro degranulation was determined by the release of β-hexosaminidase from effector cells. In vivo degranulation was monitored in human FcεRIα transgenic mice using the passive cutaneous anaphylaxis assay. These mice were also used for a vaccination study to determine the in vivo anti-cancer effects of this antibody. Significant differences in survival were determined using the Log Rank test. In vitro T-cell activation was studied using human dendritic cells and autologous T cells.

RESULTS

The anti-PSA IgE, expressed in murine myeloma cells, is properly assembled and secreted, and binds the antigen and FcεRI. In addition, this antibody is capable of triggering effector cell degranulation in vitro and in vivo when artificially cross-linked, but not in the presence of the natural soluble antigen, suggesting that such an interaction will not trigger systemic anaphylaxis. Importantly, the anti-PSA IgE combined with PSA also triggers immune activation in vitro and in vivo and significantly prolongs the survival of human FcεRIα transgenic mice challenged with PSA-expressing tumors in a prophylactic vaccination setting.

CONCLUSIONS

The anti-PSA IgE exhibits the expected biological properties and is capable of triggering immune activation and anti-tumor protection. Further studies on this antibody as a potential PCa therapy are warranted.

Insights into the mechanism of cell death induced by saporin delivered into cancer cells by an antibody fusion protein targeting the transferrin receptor 1

We previously developed an antibody-avidin fusion protein (ch128.1Av) that targets the human transferrin receptor 1 (TfR1) and exhibits direct cytotoxicity against malignant B cells in an iron-dependent manner. ch128.1Av is also a delivery system and its conjugation with biotinylated saporin (b-SO6), a plant ribosome-inactivating toxin, results in a dramatic iron-independent cytotoxicity, both in malignant cells that are sensitive or resistant to ch128.1Av alone, in which the toxin effectively inhibits protein synthesis and triggers caspase activation. We have now found that the ch128.1Av/b-SO6 complex induces a transcriptional response consistent with oxidative stress and DNA damage, a response that is not observed with ch128.1Av alone. Furthermore, we show that the antioxidant N-acetylcysteine partially blocks saporin-induced apoptosis suggesting that oxidative stress contributes to DNA damage and ultimately saporin-induced cell death. Interestingly, the toxin was detected in nuclear extracts by immunoblotting, suggesting the possibility that saporin might induce direct DNA damage. However, confocal microscopy did not show a clear and consistent pattern of intranuclear localization. Finally, using the long-term culture-initiating cell assay we found that ch128.1Av/b-SO6 is not toxic to normal human hematopoietic stem cells suggesting that this critical cell population would be preserved in therapeutic interventions using this immunotoxin.

Synergistic effect of thrombin and CD40 ligand on endothelial matrix metalloproteinase-10 expression and microparticle generation in vitro and in vivo

OBJECTIVE

Thrombin induces CD40 ligand (CD40L) and matrix metalloproteinases (MMPs) under inflammatory/prothrombotic conditions. Thrombin and CD40L could modulate endothelial MMP-10 expression in vitro and in vivo.

METHODS AND RESULTS

Human endothelial cells were stimulated with thrombin (0.1-10 U/mL), CD40L (0.25-1 μg/mL), or their combination (thrombin/CD40L) to assess MMP-10 expression and microparticle generation. Thrombin/CD40L elicited higher MMP-10 mRNA (5-fold; P<0.001) and protein levels (4.5-fold; P<0.001) than either stimulus alone. This effect was mimicked by a protease-activated receptor-1 agonist and antagonized by hirudin, a-protease-activated receptor-1, α-CD40L, and α-CD40 antibodies. The synergistic effect was dependent on p38 mitogen-activated protein kinase and c-Jun N-terminal kinase-1 pathways. Thrombin also upregulated the expression of CD40 in endothelial cell surface increasing its availability, thereby favoring its synergistic effects with CD40L. In mice, thrombin/CD40L further increased the aortic MMP-10 expression. Septic patients with systemic inflammation and enhanced thrombin generation (n=60) exhibited increased MMP-10 and soluble CD40L levels associated with adverse clinical outcome. Endothelial and systemic activation by thrombin/CD40L and lipopolysaccharide also increased microparticles harboring MMP-10 and CD40L.

CONCLUSIONS

Thrombin/CD40L elicited a strong synergistic effect on endothelial MMP-10 expression and microparticles containing MMP-10 in vitro and in vivo, which may represent a new link between inflammation/thrombosis with prognostic implications.

Targeting HER2/neu with a fully human IgE to harness the allergic reaction against cancer cells

Breast and ovarian cancer are two of the leading causes of cancer deaths among women in the United States. Overexpression of the HER2/neu oncoprotein has been reported in patients affected with breast and ovarian cancers, and is associated with poor prognosis. To develop a novel targeted therapy for HER2/neu expressing tumors, we have constructed a fully human IgE with the variable regions of the scFv C6MH3-B1 specific for HER2/neu. This antibody was expressed in murine myeloma cells and was properly assembled and secreted. The Fc region of this antibody triggers in vitro degranulation of rat basophilic cells expressing human FcεRI (RBL SX-38) in the presence of murine mammary carcinoma cells that express human HER2/neu (D2F2/E2), but not the shed (soluble) antigen (ECD(HER2)) alone. This IgE is also capable of inducing passive cutaneous anaphylaxis in a human FcεRIα transgenic mouse model, in the presence of a cross-linking antibody, but not in the presence of soluble ECD(HER2). Additionally, IgE enhances antigen presentation in human dendritic cells and facilitates cross-priming, suggesting that the antibody is able to stimulate a secondary T-cell anti-tumor response. Furthermore, we show that this IgE significantly prolongs survival of human FcεRIα transgenic mice bearing D2F2/E2 tumors. We also report that the anti-HER2/neu IgE is well tolerated in a preliminary study conducted in Macaca fascicularis (cynomolgus) monkeys. In summary, our results suggest that this IgE should be further explored as a potential therapeutic against HER2/neu overexpressing tumors, such as breast and ovarian cancers.

Early thrombosis of a tricuspid annuloplasty ring and mild hyperhomocysteinemia

Tricuspid annuloplasty ring thrombosis is an extremely infrequent pathology, and no evidence-based antithrombotic management has been described. We present the case of a 40-year-old female with isolated mild hyperhomocysteinemia and early ring thrombus formation after surgical primary closure of an atrial septal defect and ring tricuspid annuloplasty. Clinical management, antithrombotic treatment, and hyperhomocysteinemia implications are discussed.

The transferrin receptor and the targeted delivery of therapeutic agents against cancer

BACKGROUND

Traditional cancer therapy can be successful in destroying tumors, but can also cause dangerous side effects. Therefore, many targeted therapies are in development. The transferrin receptor (TfR) functions in cellular iron uptake through its interaction with transferrin. This receptor is an attractive molecule for the targeted therapy of cancer since it is upregulated on the surface of many cancer types and is efficiently internalized. This receptor can be targeted in two ways: 1) for the delivery of therapeutic molecules into malignant cells or 2) to block the natural function of the receptor leading directly to cancer cell death.

SCOPE OF REVIEW

In the present article we discuss the strategies used to target the TfR for the delivery of therapeutic agents into cancer cells. We provide a summary of the vast types of anti-cancer drugs that have been delivered into cancer cells employing a variety of receptor binding molecules including Tf, anti-TfR antibodies, or TfR-binding peptides alone or in combination with carrier molecules including nanoparticles and viruses.

MAJOR CONCLUSIONS

Targeting the TfR has been shown to be effective in delivering many different therapeutic agents and causing cytotoxic effects in cancer cells in vitro and in vivo.

GENERAL SIGNIFICANCE

The extensive use of TfR for targeted therapy attests to the versatility of targeting this receptor for therapeutic purposes against malignant cells. More advances in this area are expected to further improve the therapeutic potential of targeting the TfR for cancer therapy leading to an increase in the number of clinical trials of molecules targeting this receptor. This article is part of a Special Issue entitled Transferrins: molecular mechanisms of iron transport and disorders.

Blue-green to near-IR switching electroluminescence from Si-rich silicon oxide/nitride bilayer structures

Blue-green to near-IR switching electroluminescence (EL) has been achieved in a metal-oxide-semiconductor light emitting device, where the dielectric has been replaced by a Si-rich silicon oxide/nitride bilayer structure. To form Si nanostructures, the layers were implanted with Si ions at high energy, resulting in a Si excess of 19%, and subsequently annealed at 1000 °C. Transmission electron microscopy and EL studies allowed ascribing the blue-green emission to the Si nitride related defects and the near-IR band with the emission of the Si-nanoclusters embedded into the SiO(2) layer. Charge transport analysis is reported and allows for identifying the origin of this two-wavelength switching effect.

Metal-nitride-oxide-semiconductor light-emitting devices for general lighting

The potential for application of silicon nitride-based light sources to general lighting is reported. The mechanism of current injection and transport in silicon nitride layers and silicon oxide tunnel layers is determined by electro-optical characterization of both bi- and tri-layers. It is shown that red luminescence is due to bipolar injection by direct tunneling, whereas Poole-Frenkel ionization is responsible for blue-green emission. The emission appears warm white to the eye, and the technology has potential for large-area lighting devices. A photometric study, including color rendering, color quality and luminous efficacy of radiation, measured under various AC excitation conditions, is given for a spectrum deemed promising for lighting. A correlated color temperature of 4800K was obtained using a 35% duty cycle of the AC excitation signal. Under these conditions, values for general color rendering index of 93 and luminous efficacy of radiation of 112 lm/W are demonstrated. This proof of concept demonstrates that mature silicon technology, which is extendable to low-cost, large-area lamps, can be used for general lighting purposes. Once the external quantum efficiency is improved to exceed 10%, this technique could be competitive with other energy-efficient solid-state lighting options.

Visualization and quantification of cytotoxicity mediated by antibodies using imaging flow cytometry

Conventional approaches for the detection of antibody dependent cell-mediated cytotoxicity (ADCC) activity rely on quantification of the release of traceable compounds from target cells or flow cytometry analysis of population-wide phenomena. We report a new method for the direct imaging and quantification of ADCC of cancer cells. The proposed method using imaging flow cytometry combines the statistical power of flow cytometry with the analytical advantages of cell imaging, providing a novel and more comprehensive perspective of effector/target cell interactions during ADCC events. With this method we can quantify and show in detail the morphological changes in target and effector cells, their apoptotic index, the physical interaction between effector and target cells, and a directional transfer of cytosolic contents from effector to target cells. As a model system we used the therapeutic anti-CD20 antibody rituximab to target CFSE labeled Ramos human Burkitt's lymphoma cells, to CMTPX-labeled human monocytic U-937 effector cells. We expect that similar studies using different effector and target cell populations may contribute to the pre-clinical evaluation of therapeutic antibodies and help to identify mechanisms that could be beneficial in the immunotherapy of cancer.

Association between serum soluble CD40 ligand levels and mortality in patients with severe sepsis

INTRODUCTION

CD40 Ligand (CD40L) and its soluble counterpart (sCD40L) are proteins that exhibit prothrombotic and proinflammatory properties on binding to their cell surface receptor CD40. The results of small clinical studies suggest that sCD40L levels could play a role in sepsis; however, there are no data on the association between sCD40L levels and mortality of septic patients. Thus, the aim of this study was to determine whether circulating sCD40L levels could be a marker of adverse outcome in a large cohort of patients with severe sepsis.

METHODS

This was a multicenter, observational and prospective study carried out in six Spanish intensive care units. Serum levels of sCD40L, tumour necrosis factor-alpha and interleukin-10, and plasma levels of tissue factor were measured in 186 patients with severe sepsis at the time of diagnosis. Serum sCD40L was also measured in 50 age- and sex-matched controls. Survival at 30 days was used as the endpoint.

RESULTS

Circulating sCD40L levels were significantly higher in septic patients than in controls (P = 0.01), and in non-survivors (n = 62) compared to survivors (n = 124) (P = 0.04). However, the levels of CD40L were not different regarding sepsis severity. Logistic regression analysis showed that sCD40L levels >3.5 ng/mL were associated with higher mortality at 30 days (odds ratio = 2.89; 95% confidence interval = 1.37 to 6.07; P = 0.005). The area under the curve of sCD40L levels >3.5 ng/mL as predictor of mortality at 30 days was 0.58 (95% CI = 0.51 to 0.65; P = 0.03).

CONCLUSIONS

In conclusion, circulating sCD40L levels are increased in septic patients and are independently associated with mortality in these patients; thus, its modulation could represent an attractive therapeutic target.

Heavy metals in northern Chilean rivers: spatial variation and temporal trends

Rivers of central-northern Chile are exposed to pollution from different sources, including mining activities, natural orogenic process, volcanic activity, and geology. In order to determine the contribution of mining to river pollution, the spatio-temporal dynamics of chemical species dissolved in 12 rivers of central-northern Chile was assessed. Of all the rivers studied, the Elqui showed the highest historical mean concentrations of As, Cu and Pb. The Aconcagua had the highest concentration of Hg and a large Cr concentration, while the Rapel showed elevated concentrations of Cu and Mo. The Elqui and the Aconcagua were clustered as distinct groups by a cluster analysis based on two independent principal components. Hierarchical Bayesian models showed annual trends but no seasonal effects in heavy metal concentrations. As and Cu in the Elqui had positive annual slopes. Sulphate concentration exceeded 100 mg L(-1) in nine rivers, and in seven of them it had positive annual slopes. Our findings suggest that mining pollution is the main process contributing to this increasing annual trend in As, Cu and SO(4)(2-). Therefore, in order to improve the water quality of these rivers it is necessary to identify the main sources of heavy metals associated with mining activities.

Disruption of HOX activity leads to cell death that can be enhanced by the interference of iron uptake in malignant B cells

The HOX genes encode a family of transcription factors that are dysregulated in several malignancies and have been implicated in oncogenesis and cancer cell survival. Disruption of HOX protein function using the peptide HXR9 has shown anti-tumor effects against melanoma, lung cancer and renal cancer. In this report, we evaluated the expression of all 39 HOX genes in a panel of six malignant B-cell lines, including multiple myeloma cells and found different levels of expression of HOX family members suggesting that they also have a role in malignant B-cell survival. We show that disrupting HOX function using the peptide HXR9 induces significant cytotoxicity in the entire panel of cell lines. Importantly, we found that the cytotoxic effects of HXR9 can be enhanced by combining it with ch128.1Av, an antibody-avidin fusion protein specific for the human transferrin receptor 1 (CD71). Iron starvation induced by the fusion protein contributes to the enhanced effect and involves, at least in part, the induction of a caspase-independent pathway. These results show the relevance of HOX proteins in malignant B-cell survival and suggest that our therapeutic strategy may be effective in the treatment of incurable B-cell malignancies such as multiple myeloma.

[Differences in the use of tigecycline between ICU patients and non-ICU patients]

BACKGROUND

Tigecycline is a new broad spectrum antibiotic that is predominantly used for the treatment of severe infections both in critically ill patients admitted to the ICU and in non-ICU patients with less severe clinical conditions.

OBJECTIVE

To assess differences in the use of tigecycline between ICU patients and non-ICU patients treated with this antibiotics.

MATERIALS AND METHODS

Retrospective, cohort, observational study in which cases were defined as patients who received one or more doses of tigecycline over the first 18 months after approval of the drug in a general hospital. Clinical characteristics, indications, route of administration, clinical response, tolerability and outcome were recorded in the groups of ICU and non-ICU patients. Descriptive data and results of the comparison of both cohorts are presented.

RESULTS

A total of 103 were included in the study, 34(33%) of which received tigecycline during their stay in the ICU. ICU patients compared to non-ICU patients had a higher SAPS II score on admission (39.0 +/- 11.8 vs 26.3 +/- 8.0, p < 0.001) and at the time of starting tigecycline treatment (42.2 +/- 12.6 vs 25.6 +/- 8.2, p < 0.001), were treated with antibiotics for more days (21.4 +/- 30.6 vs 13.6 +/- 30.5 days, p < 0.012) and received a greater number of antibiotic agents concomitantly (85.3% vs 47.8%,p < 0.001), presented a higher selection of emerging bacterial flora (41.2% vs 15.9%, p =0.005), particularly Pseudomonas aeruginosa (20.6%vs 2.9%, p =0.006), higher rate of clinical failure (58.8%vs 21.7%, p < 0.001), longer hospitalization (51.2 +/- 39.4 vs 28.7 +/- 26.3 days, p < 0.001) and higher overall mortality rate (50% vs 14.5%, p < 0.001) and infection-attributed mortality (20.6% vs 7.2%, p =0.047).

CONCLUSIONS

The patient that receives tigecycline in the ICU has a higher severity level and worse clinical outcome than the non-ICU patient treated with this antibiotic. It is necessary to optimize the indications of tigecycline in the ICU to improve the clinical results.

Nutrients dynamics in the main river basins of the centre-southern region of Chile

Chilean basins have long been exposed to nutrient discharges from human activities and land use changes. A historical seasonal NO(3)(-)-N and PO(4)(3-)-P database of the last 23 years of the main nine rivers of central-southern region of Chile was analysed. Generalized additive models indicated that annual trends in NO(3)(-)-N and PO(4)(3-)-P are nonlinear. River basins such as Bío-Bío, Bueno, Imperial, Maule, Rapel and Valdivia showed a clear increase in NO(3)(-)-N, while PO(4)(3-)-P increased only in the Rapel and Maule basins. Although no seasonal difference in NO(3)(-)-N and PO(4)(3-)-P was found in the analysed basins, there was a negative relation between these nutrients and water flow. Sampling stations with high NO(3)(-)-N concentration were found mostly in sub-basins located in the "central valley" of central Chile, while several PO(4)(3-)-P "over-concentrated" sampling stations were located mostly upstream. If NO(3)(-)-N emissions into Chilean river basins continue at current rates it is probable that the concentration of this nutrient will tend to match that of the most "polluted" rivers around the world.

[Cardiac dyssynchrony correlates with left ventricular remodeling after myocardial Infarction]

BACKGROUND

Cardiac dyssynchrony is common in advanced heart failure (HF), but the changes in cardiac synchrony after myocardial infarction (MI) have not been adequately descríbed.

AIM

To study the relationship between cardiac synchrony and left ventricular remodeling after acute myocardial infarction.

MATERIAL AND METHODS

Forty nine patients aged 59+/-10 years (77% men) with a first episode of a ST segment elevation MI, were studied. Scintigraphic left ventricular function and synchrony analyses were performed at baseline and after a six months follow-up. Determinations were compared with 33 healthy subjects.

RESULTS

At baseline, patients with MIhad a decreased left ventricular ejection fraction (LVEF) and significant dyssynchrony, when compared with controls. LVEF was 36.4%+/-10%, left ventricular end-diastolic volume (LVEDV) 127+/-38 mL, interventricular delay (IEV) 29+/-35 miliseconds (ms), and intraventricular delay (IAV), 234+/-89 ms. After 6 months, LVEF significantly improved (38%+/-10%, p =0.042) without significant changes in LVEDV (129+/-32 mL, p =0.97), IEV (24+/-17, p =0.96) or IAV (231+/-97, p =0.34). At baseline there were significant correlations between IAV and LVEF, and between IAV and LVEDV (r =0.48, p =0.001 and r =0.41, p =0.004, respectively). These correlations remained significant after 6 months. There was a positive correlation between IAV and LVEDV changes at six months (r =0.403, p =0.04).

CONCLUSIONS

The development of cardiac dyssynchrony correlates with adverse left ventricular remodeling after MI .

Matrix metalloproteinase-9, -10, and tissue inhibitor of matrix metalloproteinases-1 blood levels as biomarkers of severity and mortality in sepsis

Introduction

Matrix metalloproteinases (MMPs) play a role in infectious diseases through extracellular matrix (ECM) degradation, which favors the migration of immune cells from the bloodstream to sites of inflammation. Although higher levels of MMP-9 and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) have been found in small series of patients with sepsis, MMP-10 levels have not been studied in this setting. The objective of this study was to determine the predictive value of MMP-9, MMP-10, and TIMP-1 on clinical severity and mortality in a large series of patients with severe sepsis.

Methods

This was a multicenter, observational, and prospective study carried out in six Spanish Intensive Care Units. We included 192 (125 surviving and 67 nonsurviving) patients with severe sepsis and 50 age- and sex-matched healthy controls in the study. Serum levels of MMP-9, MMP-10, TIMP-1, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-10 were measured in patients with severe sepsis at the time of diagnosis and in healthy controls.

Results

Sepsis patients had higher levels of MMP-10 and TIMP-1, higher MMP-10/TIMP-1 ratios, and lower MMP-9/TIMP-1 ratios than did healthy controls (P < 0.001). An association was found between MMP-9, MMP-10, TIMP-1, and MMP-9/TIMP-1 ratios and parameters of sepsis severity, assessed by the SOFA score, the APACHE-II score, lactic acid, platelet count, and markers of coagulopathy. Nonsurviving sepsis patients had lower levels of MMP-9 (P = 0.037), higher levels of TIMP-1 (P < 0.001), lower MMP-9/TIMP-1 ratio (P = 0.003), higher levels of IL-10 (P < 0.001), and lower TNF-α/IL-10 ratio than did surviving patients. An association was found between MMP-9, MMP-10, and TIMP-1 levels, and TNF-α and IL-10 levels. The risk of death in sepsis patients with TIMP-1 values greater than 531 ng/ml was 80% higher than that in patients with lower values (RR = 1.80; 95% CI = 1.13 to 2.87;P = 0.01; sensitivity = 0.73; specificity = 0.45).

Conclusions

The novel findings of our study on patients with severe sepsis (to our knowledge, the largest series reporting data about MMP levels in sepsis) are that reduced MMP-9/TIMP-1 ratios and increased MMP-10 levels may be of great pathophysiologic significance in terms of severity and mortality, and that TIMP-1 levels may represent a biomarker to predict the clinical outcome of patients with sepsis.

Tissue-specific PAI-1 gene expression and glycosylation pattern in insulin-resistant old rats

Increased levels of plasminogen activator inhibitor-1 (PAI-1) have been associated with obesity, aging, insulin resistance, and type 2 diabetes, conditions that contribute to increased cardiovascular risk. PAI-1 is expressed in a variety of tissues, but the cellular origin of plasma PAI-1 is unknown. To link insulin resistance, aging, and cardiovascular disease, we examined the expression and glycosylation pattern of PAI-1 in liver and white adipose tissue (WAT) from adult (3 mo) and insulin-resistant old (24 mo) Wistar rats. Glycosylated PAI-1 protein was also purified by affinity chromatography from endothelial culture supernatans to analyze its inhibitory activity. We also analyzed the contribution of adipocytes and stromal vascular cells from WAT to PAI-1 levels with aging. Aging caused a significant increase of PAI-1 mRNA (P < 0.001) in WAT that was predominantly due to the adipocytes and not to stroma-vascular cells, while there was no modification in liver from aged rats. Moreover, PAI-1 expression increased during preadipocyte differentiation (P < 0.001). Furthermore, we found a tissue-dependent PAI-1 glycosylation pattern: adipose tissue only expresses the glycosylated PAI-1 form, whereas the liver mainly expresses the nonglycosylated form. Finally, we also found evidences suggesting that the glycosylated PAI-1 form shows higher inhibitory activity than the nonglycosylated. Our data suggest that WAT may be a major source of the elevated plasma levels of PAI-1 in insulin-resistant old rats. Additionally, the high degree of PAI-1 glycosylation and activity, together with the significant increase in visceral fat in old rats, may well contribute to an increased cardiovascular risk associated with insulin-resistant states.

Matrix metalloproteinase-10 is upregulated by thrombin in endothelial cells and increased in patients with enhanced thrombin generation

OBJECTIVE

Thrombin is a multifunctional serine protease that promotes vascular proinflammatory responses whose effect on endothelial MMP-10 expression has not previously been evaluated.

METHODS AND RESULTS

Thrombin induced endothelial MMP-10 mRNA and protein levels, through a protease-activated receptor-1 (PAR-1)-dependent mechanism, in a dose- and time-dependent manner. This effect was mimicked by a PAR-1 agonist peptide (TRAP-1) and antagonized by an anti-PAR-1 blocking antibody. MMP-10 induction was dependent on extracellular regulated kinase1/2 (ERK1/2) and c-jun N-terminal kinase (JNK) pathways. By serial deletion analysis, site-directed mutagenesis and electrophoretic mobility shift assay an AP-1 site in the proximal region of MMP-10 promoter was found to be critical for thrombin-induced MMP-10 transcriptional activity. Thrombin and TRAP-1 upregulated MMP-10 in murine endothelial cells in culture and in vivo in mouse aorta. This effect of thrombin was not observed in PAR-1-deficient mice. Interestingly, circulating MMP-10 levels (P<0.01) were augmented in patients with endothelial activation associated with high (disseminated intravascular coagulation) and moderate (previous acute myocardial infarction) systemic thrombin generation.

CONCLUSIONS

Thrombin induces MMP-10 through a PAR-1-dependent mechanism mediated by ERK1/2, JNK, and AP-1 activation. Endothelial MMP-10 upregulation could be regarded as a new proinflammatory effect of thrombin whose pathological consequences in thrombin-related disorders and plaque stability deserve further investigation.

AllergoOncology: the role of IgE-mediated allergy in cancer

Epidemiological studies have suggested inverse associations between allergic diseases and malignancies. As a proof of concept for the capability of immunoglobulin E (IgE) to destruct tumor cells, several experimental strategies have evolved to specifically target this antibody class towards relevant tumor antigens. It could be demonstrated that IgE antibodies specific to overexpressed tumor antigens have been superior to any other immunoglobulin class with respect to antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) reactions. In an alternative approach, IgE nonspecifically attached to tumor cells proved to be a powerful adjuvant establishing tumor-specific immune memory. Active Th2 immunity could also be achieved by applying an oral immunization regimen using mimotopes, i.e. epitope mimics of tumor antigens. The induced IgE antibodies could be cross-linked by live tumor cells leading to tumoricidic mediator release. Thus, IgE antibodies may not only act in natural tumor surveillance, but could possibly also be exploited for tumor control in active and passive immunotherapy settings. Thereby, eosinophils, mast cells and macrophages can be armed with the cytophilic IgE and become potent anti-tumor effectors, able to trace viable tumor cells in the tissues. It is strongly suggested that the evolving new field AllergoOncology will give new insights into the role of IgE-mediated allergy in malignancies, possibly opening new avenues for tumor therapy.

[Chronic anemia in heart transplant patients: prevalence, predisposing factors and prognostic significance]

INTRODUCTION AND OBJECTIVES

Data on chronic anemia following heart transplantation (HT) are scarce and contradictory. Our aims were to determine the prevalence of chronic anemia after HT, to identify predisposing factors for the condition at 12 months, and to evaluate its influence on medium-term and long-term survival.

METHODS

Retrospective analysis of patients who underwent HT between 1991 and 2005 (n=457). Chronic anemia was defined as a hemoglobin level <12 g/dL.

RESULTS

The prevalence of post-HT chronic anemia was 75.5% at 1 month, 31% at 12 months, and 26.2% at 120 months. The condition was significantly more prevalent among women than men. Predisposing factors for chronic anemia 1 year post-HT were mild-to-moderate chronic renal failure (i.e., creatinine level >1.5 mg/dL; odds ratio [OR]=2.8; 95% confidence interval [CI], 1.5-5.0), female sex (OR=6.4; 95% CI, 3.1-13.2), and immunosuppression with mycophenolate mofetil compared with azathioprine (OR=2.6;, 95% CI, 1.4-4.8). The prevalence of chronic anemia 12 months after HT was independent of the donor's sex, the recipient's age, the etiology of the recipient's heart failure, diabetes mellitus, mild-to-moderate graft rejection, cytomegalovirus infection, and angiotensin-converting enzyme inhibitor treatment. The presence of chronic anemia 12 months after HT did not influence either long-term survival (mean, 11.5 years with chronic anemia vs. 13.0 years without) or actuarial survival.

CONCLUSIONS

Post-HT chronic anemia is common, but improves with time and treatment. Predisposing factors for the condition 1 year post-HT include chronic renal failure, female sex, and immunosuppression with mycophenolate mofetil. The presence of chronic anemia does not appear to influence long-term survival.

[Hypokalemia, hypovolemia and electrocardiographic changes due to furosemide abuse. Report of one case]

Hypokalemia (serum K+ < 3.5 mEq/1) is a potentially serious adverse effect of diuretic ingestion. We report a 27 year-old woman admitted with muscle weakness, a serum potassium of 2.0 mEq/1, metabolic alkalosis and EKG abnormalities simulating cardiac ischemia, that reverted with potassium chloride administration. She admitted high dose furosemide self-medication for edema. Glomerular filtration rate, tubular sodium reabsorption, potassium secretion, the renin-aldosterone system, total body water distribution and capillary permeability, were studied sequentially until 90 days after her admission. There was hyperactivity of the renin-aldosterone axis, reduction in extracellular and intracellular volumes, normal capillary permeability and high sodium tubular reabsorption, probably explained by a "rebound" salt retention associated with her decreased extracellular volume.

[Atherosclerosis in inflammatory diseases]

The recognition that inflammation is a hallmark of atherosclerotic disease and its complications has led to a series of studies reporting high prevalence of atherosclerosis in chronic inflammatory diseases. Indeed, chronic immune diseases, such as systemic lupus erythematosus and rheumatoid arthritis, are associated with proinflammation, accelerated atherosclerosis and increased incidence of cardiovascular disease. Since the susceptibility towards cardiovascular events cannot be explained by classical risk factors, disease-specific pathways have been put forward as additional risk factors, potentially important for future prevention and treatment of atherosclerosis associated with chronic inflammatory diseases.

Validation of a tubular bismuth film amperometric detector

A tubular bismuth film electrode (BFE), installed as part of a multisyringe flow injection system, was used as an amperometric detector to determine the concentration of diclofenac sodium in pharmaceutical formulations. A tubular voltammetric detection cell was employed, in which the hydrodynamic flow conditions were not disturbed. This automated method allows the continuous regeneration of the BFE, preventing passivation of the detector and improving the sensitivity of detection. The influence of several variables on this sensitivity, such as the injection volume, deposition time and flow rate were evaluated; a two-level factorial experimental design was employed for this. In optimal conditions, the linear range of the calibration curve varied from 6.0-50.0 micromol L(-1), with a detection limit of 4.3 micromol L(-1). A sampling rate of 90 determinations/h was achieved; the relative standard deviation of analytical repeatability was <3.5%. After 30 injections the bismuth film on the electrode surface was automatically renewed. The method was validated by comparing the results obtained with those provided by RP-HPLC; no significant difference were seen (p<0.05).

Metaloproteasas, remodelado vascular y syndromes aterotrombóticos

Defects in the synthesis and breakdown of the extracellular matrix (ECM) are now seen as key processes in the development of atherosclerosis and its thrombotic complications. Correlations have been observed between circulating levels of ECM biomarkers and the clinical manifestations of and risk factors for atherosclerosis. Several matrix metalloproteinases (MMPs), endopeptidases that can degrade the ECM, such as MMP-9 and MMP-10, play important roles in the pathophysiology of atherothrombosis and contribute to the expansion of abdominal aortic aneurysms. Moreover, they may also be useful biomarkers of atherosclerotic risk and serve as predictors of coronary and cerebrovascular disease recurrence. Although at present the effect of tissue inhibitors of MMPs (TIMPs) on cardiovascular disease prognosis is still uncertain, the ECM could be a promising therapeutic target in atherothrombotic disease, and several MMP inhibitors are currently undergoing clinical trials.

Long-term immunity elicited by antibody-cytokine fusion proteins protects against sequential challenge with murine mammary and colon malignancies

We have previously reported that the antibody fusion proteins anti-HER2/neu IgG3 fused to IL-12 [(IL-12)-IgG3] or GM-CSF [IgG3-(GM-CSF)] independently or in combination are effective anti-tumor agents against D2F2/E2 murine mammary cancer cells expressing human HER2/neu in the peritoneum. Importantly, the long-term survivors were immune to the subcutaneous challenge with D2F2/E2 and the parental D2F2 not expressing HER2/neu. We now show that these long-term survivors also exhibit significant protection against subsequent subcutaneous challenge with the murine colon carcinoma CT26-HER2/neu, and later against subcutaneous challenge with the parental CT26. These results suggest that the long-term systemic protection against mammary cancer elicited by treatment with antibody-cytokine fusion proteins can be extended to prevent the growth of a tumor from different origin expressing HER2/neu, and that this protection is not limited to this antigen alone, since it also prevented the growth of the parental tumor cells.

Late Steroid Withdrawal After Heart Transplantation and Incidence of Acute Rejection

BACKGROUND

Steroid withdrawal (SW) after heart transplantation (HT) reduces steroid-associated side effects, although it can increase acute rejection episodes (ARE). Patient selection criteria for SW and the time elapsed after HT for this maneuver are controversial issues. The objective of this study was to assess the safety of late SW after HT with regard to the occurrence of ARE and to analyze risk factors resulting in a poor evolution.

METHODS

We studied a cohort of 24 patients who underwent SW late after HT. All of them had gone at least 4 years without any ARE. Independent variables were time after HT, general recipient and donor data, risk factors for ARE, and immunosuppression. The dependent variables were occurrence of ARE (proven or not proven with endomyocardial biopsy) and time and severity of ARE.

RESULTS

Among 24 HT patients including 96% men with an overall mean age of 57 years who underwent SW, the mean follow-up was 2.32 +/- 0.86 years. Six patients (25%) displayed an ARE >or=2R according to the International Society for Heart and Lung Transplantation (ISHLT) at 5 +/- 3 months after SW. There were no deaths. Time from the last rejection episode to SW was 6.6 +/- 2 years. All ARE were treated with steroid boluses (mean total dose 1583 +/- 1044 mg). Among the HT patients with ARE, 5 (85%) had never experienced ARE after HT. Upon long-term follow-up, there were 2 deaths: 1 sudden death at 30 months after SW and 1 due to allograft vasculopathy at 20 months post-SW. Currently 92% are New York Heart Association (NYHA) functional class I with a mean left ventricular ejection fraction of 67% +/- 10%.

CONCLUSIONS

In our series of HT with late SW after HT (even among an HT population with a low risk of rejection), there was a 25% rate of ARE. This study did not allow us to identify risk factors for ARE after SW. We believe that based upon these observations SW should be implemented with caution.

Vulnerable Plaque Versus Vulnerable Patient: Emerging Blood Biomarkers for Risk Stratification

Biomarkers are generally considered to be plasma measurements of molecules, proteins, or enzymes that provide independent diagnostic and prognostic value by reflecting an underlying disease state or condition. In the case of coronary heart disease, they must reflect the underlying biology of the vessel wall and in particular, the atherosclerotic process and/or its sequelae. The clinical utility of a biomarker depends on its ability to account for a significant proportion of the disease being evaluated; it should be accurate and reliable; provide good sensitivity and specificity; and be available for widespread application. Data are being accumulated on the potential clinical utility of markers of inflammation, hemostasis and thrombosis, phospholipases, proteolysis and oxidative stress. Whereas C-reactive protein (CRP) emerges as a biomarker in the setting of primary prevention, we have recently found that CRP enhances the endothelial expression of metalloproteinases (MMPs). Regardless of the causality, circulating inflammatory markers have the potential to refine prediction of risk of cardiovascular events. However, a recommendation that they should be added to current risk factor scores is premature, since the benefits and costs of screening with any inflammatory marker require careful evaluation. A multimarker approach to estimate cardiovascular risk either by inflammatory markers and cumulative risk markers obtained from non-invasive tests or both may be superior to assessing a single marker.

Binding specificity and internalization properties of an antibody-avidin fusion protein targeting the human transferrin receptor

The human transferrin receptor (hTfR1) is a membrane-bound protein involved in transferrin (Tf)-mediated iron uptake and is highly expressed on malignant cells. A second version of the receptor (hTfR2) also mediates Tf-dependent iron import. We previously developed a protein composed of avidin fused to a mouse/human chimeric IgG3 specific for hTfR (anti-hTfR IgG3-Av) that was originally designed to deliver biotinylated drugs into cancer cells. We have now found that anti-hTfR IgG3-Av does not cross-react with hTfR2 and binds hTfR1 expressed on the surface of cells, attached to a solid surface, and in solution. We also found that the hemochromatosis protein (HFE), another ligand of the TfR, does not inhibit the binding of anti-hTfR IgG3-Av to the receptor. In addition, using live cell laser scanning confocal microscopy (LCLSCM) we demonstrated that anti-hTfR IgG3-Av and anti-hTfR IgG3 are internalized into cells expressing hTfR1 at a similar rate. Furthermore, our proliferation and morphological studies demonstrated the effective cytotoxicity of a biotinylated toxin delivered by anti-hTfR IgG3-Av only into cells expressing hTfR1. Our results better define the properties of anti-hTfR IgG3-Av and pave the way for the rational design of future in vitro and in vivo studies for the treatment of human malignancies.

Independent association of matrix metalloproteinase-10, cardiovascular risk factors and subclinical atherosclerosis

OBJECTIVES

Circulating levels of matrix metalloproteinase (MMP)-10 are related to inflammation in asymptomatic subjects with cardiovascular risk factors. Whether MMP-10 is associated with the severity of atherosclerosis remains to be determined. This study examines the relationship of systemic MMP-10 levels with atherosclerotic risk factors and subclinical atherosclerosis.

METHODS AND RESULTS

Circulating levels of MMP-1, -9 and -10, and markers of inflammation [fibrinogen, interleukin-6, von Willebrand factor, and high-sensitivity C-reactive protein (hs-CRP)] were measured in 400 subjects (mean age 54.3 years, 77.7% men) with cardiovascular risk factors but free from clinical cardiovascular disease. Subclinical atherosclerosis was evaluated by both the mean carotid intima-media thickness (IMT) and the presence of atherosclerotic plaques with the use of B-mode ultrasound in all subjects. MMP-10 levels were positively correlated with fibrinogen (r = 0.24, P < 0.001), hs-CRP (r = 0.14, P < 0.01) and carotid IMT (r = 0.17, P < 0.01). The association between MMP-10 and IMT remained significant in multiple regression analysis (P < 0.02) when controlling for traditional atherosclerotic risk factors and inflammatory markers. Such an association was not observed for MMP-1 and -9. Subjects in the highest MMP-10 tertile had significantly higher carotid IMT (adjusted odds ratio 6.3, 95% confidence interval 1.3-31.4, P = 0.024). In addition, MMP-10 levels were significantly higher in patients with carotid plaques (n = 78) than in those with no plaques after adjusting for age and sex (P < 0.01).

CONCLUSION

Higher serum MMP-10 levels were associated with inflammatory markers, increased carotid IMT and atherosclerotic plaques in asymptomatic subjects. Circulating MMP-10 may be useful to identify subclinical atherosclerosis in subjects free from cardiovascular disease.

A density functional theory study of the dissociation of H2 on gold clusters: Importance of fluxionality and ensemble effects

Density functional theory was employed to calculate the adsorption/dissociation of H2 on gold surfaces, Au(111) and Au(100), and on gold particles from 0.7 (Au14) to 1.2 nm (Au29). Flat surfaces of the bulk metal were not active towards H2, but a different effect was observed in gold nanoclusters, where the hydrogen was adsorbed through a dissociative pathway. Several parameters such as the coordination of the Au atoms, ensemble effects and fluxionality of the particle were analyzed to explain the observed activity. The effect of the employed functional was also studied. The flexibility of the structure, i.e., its adaptability towards the adsorbate, plays a key role in the bonding and dissociation of H2. The interaction with hydrogen leads to drastic changes in the structure of the Au nanoparticles. Furthermore, it appears that not only low coordinated Au atoms are needed because H2 adsorption/dissociation was only observed when a cooperation between several (4) active Au atoms was allowed.

Cytokines fused to antibodies and their combinations as therapeutic agents against different peritoneal HER2/neu expressing tumors

We have previously generated antihuman HER2/neu-humanized IgG3 fused to interleukin-2 (IL-2), IL-12, or granulocyte macrophage colony-stimulating factor (GM-CSF) [monofunctional fusion proteins (mono-AbFP)] or fused to IL-2 and IL-12 or IL-12 and GM-CSF [bifunctional fusion proteins (bi-AbFP)]. These AbFPs retained cytokine and antigen-binding activities. We have now further characterized the AbFPs and determined the heparin-binding activity of the fused cytokines, their ability to trigger IFN-gamma secretion and natural killer (NK) activation, and their direct antitumor efficacy. Flow cytometry revealed heparin-binding activity in the AbFPs containing IL-12 and IL-2, although this activity seems to be decreased in the bi-AbFPs. However, both bi-AbFPs retained the capacity to stimulate IL-12-dependent IFN-gamma secretion in the NK cell line KY-1, and IL-12/IL-2 bi-AbFP induced NK activity in splenocytes. The antitumor effectiveness of bi-AbFPs and mono-AbFP combinations was studied in mice challenged i.p. with three different human HER2/neu murine syngeneic models (D2F2/E2, CT26-HER2/neu, and MC38-HER2/neu). Although a significant variability in the profile of antitumor response was observed in the different tumor models, the combination of IL-12 and GM-CSF mono-AbFPs protected 100% of D2F2/E2-challenged and 75% of CT26-HER2/neu-challenged mice. In contrast, bi-AbFPs protected less than the combination of mono-AbFPs and, in some models, even less than mono-AbFPs alone. However, in all cases, most of long-term survivors showed protection after s.c. rechallenge with the tumors and later with the parental tumors not expressing HER2/neu. These results show that, although the pattern of protection is tumor model dependent, treatments with AbFPs can effectively generate high levels of protection against peritoneal tumors expressing HER2/neu, which may be relevant in patients with primary or metastatic peritoneal carcinomatosis that may be observed in ovarian, colon, stomach, bladder, lung, and breast cancers.

High-performance liquid magneto-chromatography

High-performance liquid magneto-chromatography (HPLMC) is a new chromatography technique with two distinctive features: (a) a high surface area stationary phase with paramagnetic properties composed of magnetite embedded in a silica gel, and (b) a magnetic field (variable intensity 0-5.5 mT) that selectively retains paramagnetic substances in the stationary phase depending on their magnetic susceptibility. The system can also be used to separate diamagnetic compounds such as biologically active organic molecules, but these first need to be complexed with Fe and Cu compounds to render them paramagnetic. Herein, we describe the experimental setup and the relationship between the retention factor and the magnetic field intensity, i.e., the force interaction of the complexes in relation to the magnetized magnetite. The expression derived also provides the effective magnetic susceptibility (Deltachi) of the components separated.

The 4G/5G PAI-1 polymorphism influences the endothelial response to IL-1 and the modulatory effect of pravastatin

BACKGROUND

Increased plasminogen activator inhibitor (PAI-1) levels lead to impaired fibrinolytic function associated with higher cardiovascular risk. PAI-1 expression may be regulated by different inflammatory cytokines such as interleukin-1alpha (IL-1). Several polymorphisms have been described in the PAI-1 gene.

AIM

We examined the influence of the 4G/5G polymorphism in the promoter region on IL-1alpha-induced PAI-1 expression by human umbilical vein endothelial cells (HUVEC) in presence or absence of pravastatin.

METHODS AND RESULTS

Genotyped HUVEC were incubated with IL-1alpha (500 U mL(-1)) in presence or absence of pravastatin (1-10 microm). PAI-1 expression was analyzed by real time polymerase chain reaction (PCR), and PAI-1 antigen measured in supernatants by ELISA. IL-1alpha increased PAI-1 secretion in a genotype-dependent manner, and higher values were observed for 4G/4G compared with both 4G/5G and 5G/5G cultures (P < 0.05). Preincubation of HUVEC with 10 microm pravastatin significantly reduced IL-1-induced PAI-1 expression in 4G/4G HUVEC compared with untreated cultures (177.5% +/- 24.5% vs. 257.9% +/- 39.0%, P < 0.05). Pravastatin also attenuated the amount of secreted PAI-1 by 4G/4G HUVEC after IL-1 stimulation (5020.6 +/- 165.7 ng mL(-1) vs. 4261.1 +/- 309.8 ng mL(-1), P < 0.05). This effect was prevented by coincubation with mevalonate, indicating a dependence on HMG-CoA reductase inhibition.

CONCLUSIONS

The endothelial 4G/5G PAI-1 genotype influences the PAI-1 response to IL-1alpha and the modulatory effect of pravastatin. As increased PAI-1 levels have been linked to cardiovascular disease the observed endothelial modulation by pravastatin may have potential clinical implications.

Renewable stationary phase liquid magnetochromatography: determining aspartame and its hydrolysis products in diet soft drinks

A new chromatographic modality that does not require high pressures and also allows renewal of the stationary phase as desired is reported. The technique is based on a thin layer paramagnetic stationary phase (Fe3O4-SiO2) retained on the inner wall of a minicolumn through the action of an external magnetic field, which also plays an important role in separating the analytes. Accordingly, the name "renewable stationary phase liquid magnetochromatography", or RSP-LMC, has been proposed for it. The technique was used to separate and quantify the sugar substitute alpha-aspartame and its constituent amino acids (hydrolysis products), L-aspartic acid and L-phenylalanine, in diet fizzy soft drinks. When the results obtained for alpha-aspartame were compared with those obtained using HPLC as a reference method, no significant differences were observed. The system proposed is fully automated, making it an economic, competitive alternative to conventional methods of determining alpha-aspartame and its amino acid components.

C-Reactive Protein Induces Matrix Metalloproteinase-1 and -10 in Human Endothelial Cells

OBJECTIVES

We examined the effect of C-reactive protein (CRP) on matrix metalloproteinase (MMP) and inhibitor expression in endothelial cells and in patients with clinical and subclinical atherosclerosis.

BACKGROUND

In addition to predicting atherosclerotic vascular disease, CRP may directly promote a proinflammatory/proatherosclerotic phenotype.

METHODS

Human umbilical vein endothelial cells (HUVECs) and aortic endothelial cells (HAECs) were incubated in the presence or absence of CRP (50 mug/ml). Microarray analysis, real-time polymerase chain reaction, immunological and activity assays for MMPs were performed. Specific inhibitors of mitogen-activated protein kinase pathway were used. The MMP-1 and -10 plasma levels were measured in apparently healthy subjects (n = 70). Immunolocalization of CRP, MMP-1, and MMP-10 was performed in human mammary arteries and carotid endarterectomy specimens.

RESULTS

C-reactive protein augmented MMP-1 and -10 messenger ribonucleic acid expression in HUVEC (p < 0.05) and HAEC (p < 0.01). C-reactive protein stimulation also increased MMP-1 and -10 protein in conditioned culture medium (p < 0.001), as well as MMP activity (p = 0.001). Specific inhibition of p38 or MEK abolished the CRP induction of the MMP-1, whereas MMP-10 induction blockade required the simultaneous inhibition of p38 and Jun N-terminal kinase pathways. Subjects with CRP values >3 mg/l (n = 37) had increased plasma MMP-1 and -10 (p < 0.05), the association being significant after adjustment for confounding variables (p = 0.04 and p = 0.008, respectively). The MMP-10 levels were elevated in subjects with higher carotid intima-media thickness (p = 0.009). Increased CRP and MMP-10 colocalized in endothelial layer and macrophage-rich areas in advanced atherosclerotic plaques.

CONCLUSIONS

Increased local and systemic CRP-related MMP activation might provide a link between inflammation and plaque vulnerability.

Inhaled nitric oxide through a noninvasive ventilation device to assess reversibility of pulmonary hypertension in selecting recipients for heart transplant

INTRODUCTION

Pulmonary hypertension (PHT) is an independent risk factor for right ventricular failure and death after heart transplant. Nitric oxide (NO) is a powerful and selective vasodilator, indicated in this scenario, but its response is unpredictable. Thus, it should be assessed prior to the intervention. However, preoperative assessment has not been widespread due to its difficulties and risks.

OBJECTIVE

We describe herein a pulmonary vasodilatory test with NO administered through a noninvasive ventilation (NIMV) device. We also assessed the effect of NO in patients with severe PHT owing to cardiac disease. Assessment of the utility of the test to select patients for heart transplant.

METHODS

We enrolled 19 patients with severe PHT for a preoperative assessment for heart transplant. Thresholds used were as follows: systolic pulmonary arterial pressure (SPAP) > or =65 mm Hg, transpulmonary gradient (TPG) > or =15 mm Hg, and pulmonary vascular resistance (PVR) > or =4.5 Wood units (WU). NO was administered through a modified noninvasive ventilation device. Cardiac output and pulmonary pressures were measured simultaneously by right heart catheterization.

RESULTS

All patients agreed to be enrolled in the test. No difficulties, interruptions, or severe complications happened in any case. Basal and NO average measured values were SPAP (74.16 and 57.95 mm Hg), PVR (7.5 and 3.7 WU), and TPG (23.25 and 12.58 mm Hg). The differences were significant (P < .05) for all three tests. We consider acceptable for heart transplant a response that reduces PHT to a moderate grade. Using these criteria 14 patients were accepted and 11 underwent heart transplant. Two deaths in the postoperative period were both secondary to mediastinal bleeding and not related to right ventricular failure.

CONCLUSIONS

A pulmonary vasodilatory test with NO administered through a NIMV device was feasible and useful to select suitable heart transplant recipients with severe pulmonary hypertension.

Long-Term Results of Heart Transplant in Recipients Older and Younger Than 65 Years: A Comparative Study of Mortality, Rejections, and Neoplasia in a Cohort of 445 Patients

BACKGROUND

Whether being older than 65 years should be considered an absolute counterindication to heart transplant (HT), as it is in some centers, is controversial. In our centre, patients older than 65 years are accepted for HT if they satisfy stringent conditions. The aim of this study was to examine whether heart recipients older than 65 years have a greater risk of rejection, neoplasia, or mortality than younger ones.

METHODS

We studied 445 patients who underwent HT between April 1991 and December 2003, 42 of whom were older than 65 years and 403 who were 65 years or younger. The parameters evaluated were the cumulative incidences of neoplasias and rejections (ISHLT grade > or = 3A), and the survival rates 1 month, 1 year, and 5 years post-HT.

RESULTS

The two groups had similar percentages of patients with at least one rejection episode (< or =65 years 56.9%, >65 years 51.3%; P > .05), and although there were proportionally almost twice as many tumors in the older group (14.2%) as in the younger (7.9%), this difference was not statistically significant either. Nor were there any significant differences in survival, the 1-month, 1-year, and 5-year rates being 87.8%, 82.1%, and 68.8%, respectively, in the younger group and 85.7%, 78.6%, and 73.4%, respectively, in the older.

CONCLUSIONS

Among carefully selected patients aged more than 65 years, HT can be performed without incurring greater risk of rejection, malignancy, or death than is found among recipients younger than 65 years.