Reports of Large Immunosuppression Trials in Kidney Transplantation: Room for Improvement

The reporting quality of publications of clinical trials can affect the quality of clinical decision-making. We systematically assessed the quality of publications of large multicenter trials evaluating immunosuppressive regimens in de novo kidney transplantation. Study quality, reporting quality and accessibility of the results of 63 publications were assessed independently by three blinded investigators using an instrument combining the Jadad scale with a list of reporting quality items. Study quality was rated with an average of only 2.3 (range 1-5) on the Jadad scale. Unblinded studies were reported in 68.3% of publications and follow-up longer than 12 months was reported for only 13 out of 50 studies. The reviewed publications fulfilled an average of 69.1% of the reporting quality criteria. Fifty-four percent of publications did not report both treated and biopsy-proven rejections. Whether reported graft survival was censored for death could not be determined for 27% of publications. Only a few publications gave confidence intervals (CIs) or stated whether additional analyses were pre-specified. Even the largest trials of immunosuppression in kidney transplantation show considerable quality deficits in their design and publication. Additional efforts are required of investigators, editors and sponsors to achieve maximum study and reporting quality.     

Diapedesis of leukocytes: antisense oligonucleotides for rescue

Ischemia-reperfusion injury is an acute inflammatory process during which leukocytes are intimately involved. In this review, we summarize the current data on the leukocyte cell adhesion cascade in ischemia-reperfusion injury, focus upon studies which have demonstrated specific cell adhesion molecule interactions which mediate the leukocyte involvement in ischemia-reperfusion injury, and suggest future avenues of therapeutic interventions. The increased adhesion between activated vascular endothelium and peripheral blood leukocytes is central to the structural and the functional impairment in ischemia-reperfusion injury. Several families of adhesion molecules, namely the selectins, the intercellular adhesion molecules (ICAMs), and the integrins expressed either on the endothelium or on the leukocytes, are involved the cascade of events. Sequential and overlapping cellular interactions between the members of the three gene families of adhesion receptors result in adhesion of the leukocytes to the endothelium and extravasation at the site of ischemia. The functional importance of ICAM-1 and its beta2 integrin ligands in ischemia-reperfusion of the kidney has been demonstrated by monoclonal antibody blockade studies, in knockout mice and by treatment with antisense oligodeoxynulceotides (ODN). We have shown that antisense ODN for ICAM-1 protected the kidney against ischemic renal failure. In addition, in transplanted kidneys, ICAM-1 inhibition by antisense ODN ameliorates ischemia-reperfusion injury and prevents delayed graft function. Recent developments in antisense ODN technology make this a promising therapeutic approach, and antisense ODN treatment of donors or donor organs for ICAM-1 may be useful for the prevention of reperfusion injury in human renal transplantation and could influence acute and chronic graft function.     

Ischemia-reperfusion injury in renal transplantation is independent of the immunologic background

BACKGROUND: Adhesion molecule expression is important to early transplant failure. However, whether or not adhesion molecule-facilitated inflammation is antigen-dependent is unknown. We tested this hypothesis. METHODS: Rat renal grafts were four-hours cold-preserved in University of Wisconsin (UW) solution, transplanted to syngeneic or allogeneic recipients, and harvested after 2, 6, 12, 24, and 48 hours and after 1 week. The first allogeneic group receive no immunosuppression; two additional groups received either low (1.5 mg/kg) or standard (5 mg/kg) cyclosporine A (CsA). Renal function and morphology were determined; frozen sections were immunostained for P-selectin, L-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1), leukocyte function associated molecule-1 (LFA-1), very late antigen-4 (VLA-4), as well as for neutrophils and monocytes. RESULTS: Selectins increased rapidly at 2 hours and quickly decreased by 12 hours. While P-selectin was expressed on vasculature, L-selectin was found on inflammatory cells. Neutrophil influx and that of LFA-1-positive cells occurred early, peaked between 12 and 24 hours, and paralleled the maximal impairment in renal function. ICAM-1 and PECAM-1 showed similar kinetics and a diffuse distribution. VCAM-1 increased more slowly after 12 hours, peaked at 24 hours, and was localized predominantly on the endothelium of elastic vessels. Between 24 hours and 1 week, all grafts progressively developed dense VLA-4-positive monocytic infiltrates adjacent to vessels expressing VCAM-1. Functional, morphological, and immunohistochemical parameters did not differ between isografts and allografts at one week. However, by day 10, allografts showed severe vascular and cellular rejection, while injury in isografts resolved. Immunosuppression with CsA did not reverse the inflammation induced by ischemia-reperfusion injury. CONCLUSIONS: The early inflammation after ischemia-reperfusion injury is largely independent of the immunologic background. We suggest that initial injury prevention should receive the highest priority.     

Normalizing Glutamine Concentration Causes Mitochondrial Uncoupling in an In Vitro Model of Human Skeletal Muscle

Background: Glutamine has been considered essential for rapidly dividing cells, but its effect on mitochondrial function is unknown. Materials and Methods: Human myoblasts were isolated from skeletal muscle biopsy samples (n = 9) and exposed for 20 days to 6 different glutamine concentrations (0, 100, 200, 300, 500, and 5000 µM). Cells were trypsinized and manually counted every 5 days. Seven days before the end of exposure, half of these cells were allowed to differentiate to myotubes. Afterward, energy metabolism in both myotubes and myoblasts was assessed by extracellular flux analysis (Seahorse Biosciences, Billerica, MA). The protocol for myoblasts was optimized in preliminary experiments. To account for different mitochondrial density or cell count, data were normalized to citrate synthase activity. Results: Fastest myoblast proliferation was observed at 300 µM glutamine, with a significant reduction at 0 and 100 µM. Glutamine did not influence basal oxygen consumption, anaerobic glycolysis or respiratory chain capacity. Glutamine significantly (P = .015) influenced the leak through the inner mitochondrial membrane. Efficiency of respiratory chain was highest at 200–300 µM glutamine (~90% of oxygen used for adenosine triphosphate synthesis). Increased glutamine concentration to 500 or 5000 µM caused mitochondrial uncoupling in myoblasts and myotubes, decreasing the efficiency of the respiratory chain to ~70%. Conclusion: Glutamine concentrations, consistent with moderate clinical hypoglutaminemia (300 µM), bring about an optimal condition of myoblast proliferation and for efficiency of aerobic phosphorylation in an in vitro model of human skeletal muscle. These data support the hypothesis of hypoglutaminemia as an adaptive phenomenon in conditions leading to bioenergetic failure (eg, critical illness).     

Sympathetic nervous system activation and heart failure: Current state of evidence and the pathophysiology in the light of novel biomarkers

Heart failure (HF) is a complex clinical syndrome characterized by the activation of at least several neurohumoral pathways that have a common role in maintaining cardiac output and adequate perfusion pressure of target organs and tissues. The sympathetic nervous system (SNS) is upregulated in HF as evident in dysfunctional baroreceptor and chemoreceptor reflexes, circulating and neuronal catecholamine spillover, attenuated parasympathetic response, and augmented sympathetic outflow to the heart, kidneys and skeletal muscles. When these sympathoexcitatory effects on the cardiovascular system are sustained chronically they initiate the vicious circle of HF progression and become associated with cardiomyocyte apoptosis, maladaptive ventricular and vascular remodeling, arrhythmogenesis, and poor prognosis in patients with HF. These detrimental effects of SNS activity on outcomes in HF warrant adequate diagnostic and treatment modalities. Therefore, this review summarizes basic physiological concepts about the interaction of SNS with the cardiovascular system and highlights key pathophysiological mechanisms of SNS derangement in HF. Finally, special emphasis in this review is placed on the integrative and up-to-date overview of diagnostic modalities such as SNS imaging methods and novel laboratory biomarkers that could aid in the assessment of the degree of SNS activation and provide reliable prognostic information among patients with HF.     

Pretransplant Sensitization Against Angiotensin II Type 1 Receptor Is a Risk Factor for Acute Rejection and Graft Loss

The angiotensin II type 1 receptor (AT₁R) is an emerging target of functional non‐HLA antibodies (Ab). We examined the potential of determining the degree of presensitization against AT₁R as a risk factor for graft survival and acute rejection (AR). The study included 599 kidney recipients between 1998 and 2007. Serum samples were analyzed in a blinded fashion for anti‐AT₁R antibodies (AT₁R‐Abs) using a quantitative solid‐phase assay. A threshold of AT₁R‐Ab levels was statistically determined at 10 U based on the time to graft failure. An extended Cox model determined risk factors for occurrence of graft failure and a first AR episode. AT₁R‐Abs >10 U were detected in 283 patients (47.2%) before transplantation. Patients who had a level of AT₁R‐Abs >10 U had a 2.6‐fold higher risk of graft failure from 3 years posttransplantation onwards (p = 0.0005) and a 1.9‐fold higher risk of experiencing an AR episode within the first 4 months of transplantation (p = 0.0393). Antibody‐mediated rejection (AMR) accounted for 1/3 of AR, whereby 71.4% of them were associated with >10 U of pretransplant AT₁R‐Abs. Pretransplant anti‐AT₁R‐Abs are an independent risk factor for long‐term graft loss in association with a higher risk of early AR episodes.     

The sensitivity of scintigraphic myocardial imaging by the use of 99mTc-labelled pyrophosphate in the diagnosis of cardiomyopathy of various etiology.

A total of 10 patients were examined. In five children who suffered from secondary cardiomyopathy accompanying progressive muscular dystrophy scintigraphic examination of the myocardium was made using 99mTc-labelled pyrophosphate. In two cases the scan was distinctly positive, in three cases negative. Five men with poorly defined primary nonobstructive cardiomyopathy were examined too. The scan was positive in three cases and negative in two cases. The positivity of the pyrophosphate scan of the heart is therefore not pathonomonic of ischaemic damage. An increased accumulation of pyrophosphate in the myocardium in cardiomyopathy indicates an acute phase of the disease.     

Defining the extent of cables loss in endometrial cancer subtypes and its effectiveness as an inhibitor of cell proliferation in malignant endometrial cells in vitro and in vivo

Loss of Cables expression is associated with a high incidence of endometrial hyperplasia and endometrial adenocarcinoma in humans. The Cables mutant mouse develops endometrial hyperplasia and following exposure to chronic estrogen develops early endometrial adenocarcinoma. The objectives of the current study were to determine if: (1) loss of Cables expression occurred in high grade endometrioid adenocarcinoma, uterine serous and clear cell carcinoma as observed in endometrial hyperplasia and low grade endometrial adenocarcinoma; (2) overexpression of Cables inhibited cell proliferation in endometrial cancer (EC) cells in vitro and in vivo; and (3) progesterone could regulate the expression of Cables mRNA. Hyperplastic endometrium and low and high grade endometrioid adenocarcinoma showed loss of Cables expression when compared to benign control secretory endometrium. Loss of Cables expression in serous and clear cell tumors was similar to that observed in endometrioid adenocarcinomas with greater than 80% showing loss of protein expression. Treatment of EC lines with progesterone increased cables expression in low-grade EC whereas it had no effect on cables expression in cells derived from high-grade EC. The progesterone-induced increase in cables was abrogated in the presence of a progesterone receptor (PR) antagonist, suggesting the PR mediates the increase. Cables overexpression inhibited cell proliferation of well differentiated EC cells and had no effect on the poorly differentiated EC cells. The capacity to form tumors was dramatically reduced in the Cables overexpressing cell lines compared to those cells containing the control vector. Collectively these results suggest that Cables is an important regulator of cell proliferation and loss of Cables expression contributes to the development of all types of EC.     

Chest wall dose in MammoSite breast brachytherapy: radiobiologic estimations of late complication risk based on dose-volume considerations

PURPOSE: To estimate the risk of late effects in women treated with MammoSite brachytherapy (MBT), the balloon catheters of which were placed near the ribs. METHODS AND MATERIALS: Upon reviewing 93 plans, 16 patients (17%) treated with MBT were considered to have received a high chest wall dose (>or=120% isodose line in contact with a rib). A dose-volume histogram was generated for this rib, and its distance from the MBT balloon measured. Using the linear quadratic equation, the equivalent dose, delivered in 10 fractions, to the dose that causes a 5% and 50% risk of rib late effects at 5 years using 2Gy per fraction, was calculated to be 37 and 44Gy, respectively. The rib volume receiving greater than or equal to these doses (V37 and V44) was correlated to the balloon-to-rib distance. Chest wall signs, symptoms, and radiologic findings for all 16 patients were recorded. RESULTS: The median balloon-to-rib distance was 4.8mm. The median values of V37 and V44 were 13.5% and 3.3%, respectively. All patients with a V37>or=15% and V44>or=5% had a minimum balloon-to-rib distance of <5mm. Two patients reported treatment-related chest wall tenderness (both had balloons placed <5mm from the chest wall), but neither presented with radiologic complications. CONCLUSIONS: Sixteen patients considered to receive relatively high chest wall doses had less than one-third of their primary rib volume being exposed to the estimated TD 5/5 and TD 50/5 doses. Therefore, we estimate the risk of late effects in women treated with MBT, the balloon catheters of which placed near the ribs were negligible, and believe that MBT remains a safe and effective treatment for selected patients with early stage breast cancer.