Fokko J. van der Woude

The risk of skin cancer in renal transplant recipients in Queensland, Australia. A follow-up study.

A long-term retrospective follow-up study was performed to evaluate the risk of skin cancer in 1098 renal transplant recipients in Queensland, Australia. In a subgroup, we also assessed the influence of immunosuppressive therapy on the risk of developing skin cancer: cyclosporine alone or in combination with prednisolone; azathioprine alone or in combination with prednisolone; or the combination of cyclosporine and azathioprine with or without prednisolone. The cumulative incidence of developing skin cancer, calculated by life table analysis, increased progressively from 7% after 1 year of immunosuppression to 45% after 11 years and to 70% after 20 years of immunosuppression. Multivariate analysis in a subgroup comparing the risk of developing skin cancer in patients on either long-term cyclosporine or azathioprine (each with or without prednisolone) and in patients on the combination of cyclosporine and azathioprine (with or with- out prednisolone) showed no differences between the groups. We conclude that it is likely that the increased risk of skin cancer associated with immunosuppression is independent of the agent(s) used and is a result of the immunosuppression per se.

The relation between acute vascular and interstitial renal allograft rejection and subsequent chronic rejection

Chronic rejection of renal allografts is a major cause of late graft loss. However, time of onset, relation with acute early rejection episodes, and risk factors are largely unknown. We undertook a cohort study of 482 consecutive patients from a single center who received a cadaveric renal allograft between January 1983 and April 1991. During the first 3 months after transplantation, 76 (15.8%) patients developed vascular rejection and 115 (23.9%) developed interstitial rejection. One-year graft survival of patients without rejection, with interstitial rejection, and with vascular rejection was 87.8%, 87%, and 48.7%, respectively. Five-year graft survival was 73.5% for the group without rejection, 71.4% for patients with interstitial rejection, and 34.3% for patients with vascular rejection. The adjusted relative risk of graft loss was 4.92 (95% CI 3.25–7.43) for patients with vascular rejection and 1.27 (95% CI 0.80–2.02) for patients with interstitial rejection compared with patients without early rejection, taking the time dependency of the rejection events and prognostic factors into account. The incidence of vascular rejection was increased in patients with primary nonfunction (RR 1.69, 95% CI 1.01–2.84), with 1 HLA-DR mismatch (RR 2.38, 95% CI 1.44–3.93), with 2 HLA-DR mismatches (RR 3.24, 95% CI 1.25–8.42), with a prolonged cold ischemia time (RR 1.03, 95% CI 1.00–1.06 per hr), and with 1 or more previous transplantations (RR 1.76, 95% CI 1.01–3.07). Risk of developing vascular rejection was decreased in patients using CsA as compared with azathioprine (RR 0.41, 95% CI 0.24–0.67). Early vascular rejection, occurring within 3 months after transplantation, is the most important predicting variable of both early and late graft loss. Use of CsA, less HLA-DR mismatching, and a cold ischemiatime of short duration possibly prevent the development of vascular rejection.

15-Deoxyspergualin in Patients with Refractory ANCA-Associated Systemic Vasculitis: A Six-Month Open-Label Trial to Evaluate Safety and Efficacy

The combination of cyclophosphamide (CYC) and oral corticosteroids is effective in the majority of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AASV), but it carries substantial risk of drug-related morbidity and mortality. New regimens are desired, especially in refractory cases. The immunosuppressant 15-deoxyspergualin (DSG) is effective in experimental autoimmune disease and transplantation as well as in acute kidney transplant rejection in humans. To assess the efficacy and safety of DSG, an open label multicenter trial was conducted in patients with AASV who were either unresponsive or had contraindications for standard immunosuppressants. Included were 19 cases of Wegener granulomatosis and one case of microscopic polyangiitis. Nine of them had received CYC shortly before study entry without apparent therapeutic success. DSG (0.5 mg/kg per d) was given for 2 to 3 wk until the WBC count dropped to 3000/ micro l followed by a rest until at least a WBC of 4000/ micro l was reached again. This was repeated up to six cycles. During the study, no other immunosuppressants besides steroids were allowed. Disease improvement during treatment with DSG was achieved in 70% of cases (six cases of complete remission; eight cases of partial remission). Leucopenia occurred in each patient in a regular pattern during the cycles and was transient without exception. No mortality or septicemia was observed. Mild to moderate infections mainly in the respiratory tract were observed but resolved under adequate treatment without sequel. It is concluded that treatment with DSG is successful in patients with refractory Wegener granulomatosis under careful monitoring of WBC count.

The effect of grapefruit juice on cyclosporine and prednisone metabolism in transplant patients

To estimate the effect of grapefruit juice on cyclosporine and prednisone metabolism.

Increased circulating endothelial progenitor cells in septic patients: Correlation with survival

Objective:Endothelial damage and detachment of endothelial cells are known to occur in septic patients. Thus, recruitment of circulating endothelial progenitor cells (cEPCs) to these lesions might have a beneficial effect on the clinical course in septic patients. Therefore, we were interested in whether EPCs, detected by flow cytometry, are increasingly mobilized during sepsis and if this mobilization is associated with clinical outcome. Design:Prospective, nonrandomized study. Setting:Intensive care unit of a university hospital. Patients:Patients with (n = 32) and without (n = 15) sepsis and healthy volunteers (n = 15). Interventions:Peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation, and cEPCs were characterized by three-color fluorescence flow cytometry using antibodies against CD133, CD34, and vascular endothelial growth factor receptor-2. Serum concentrations of vascular endothelial growth factor, granulocyte macrophage-colony stimulating factor, and erythropoietin were determined by enzyme-linked immunosorbent assay. Severity of sepsis was assessed according to Acute Physiology and Chronic Health Evaluation II scoring. Measurements and Main Results:In septic patients, the number of cEPCs was significantly higher than in nonseptic intensive care unit patients (p < .05) and healthy controls (p < .02). Nonsurvivors (n = 8), defined as death within 28 days after onset of sepsis, had significantly lower numbers of cEPCs than survivors (n = 24) (p < .0001). The number of cEPCs was correlated with survival in septic patients. Serum vascular endothelial growth factor concentrations were significantly higher in septic patients compared with nonseptic intensive care unit patients and healthy controls (p < .01) and correlated with the cEPC numbers (p < .0001). Similar findings were observed for granulocyte macrophage-colony stimulating factor and erythropoietin. Conclusions:Our data suggest that cEPC enumeration in peripheral blood of septic patients might be a valuable marker to assess the clinical outcome in these patients.

l-Carnosine, a Substrate of Carnosinase-1, Influences Glucose Metabolism

OBJECTIVE—Carnosinase 1 (CN1) is a secreted dipeptidase that hydrolyzes l-carnosine. Recently, we have identified an allelic variant of human CN1 (hCN1) that results in increased enzyme activity and is associated with susceptibility for diabetic nephropathy in human diabetic patients. We therefore hypothesized that l-carnosine in the serum represents a critical protective factor in diabetic patients. RESEARCH DESIGN AND METHODS—l-carnosine serum levels were manipulated in db/db mice, a model of type 2 diabetes. In a transgenic approach, hCN1 cDNA was expressed under the control of a liver-specific promoter in db/db mice, mimicking the expression pattern of hCN1 in humans. RESULTS—Fasting plasma glucose as well as A1C levels rose significantly earlier and remained higher in transgenic animals throughout life. Body weights were reduced as a result of significant glucosuria. In an opposite approach, nontransgenic db/db mice were supplemented with l-carnosine. In these latter mice, diabetes manifested significantly later and milder. In agreement with the above data, serum fasting insulin levels were low in the transgenic mice and elevated by l-carnosine feeding. Insulin resistance and insulin secretion were not significantly affected by l-carnosine serum levels. Instead, a significant correlation of l-carnosine levels with β-cell mass was observed. CONCLUSIONS—hCN1-dependent susceptibility to diabetic nephropathy may at least in part be mediated by altered glucose metabolism in type 2 diabetic patients.

Prevention of Cold‐Preservation Injury of Cultured Endothelial Cells by Catecholamines and Related Compounds

The present study was conducted to dissect the underlying mechanisms by which catecholamines protect cells against preservation injury.

Hypothermic injury: the mitochondrial calcium, ATP and ROS love-hate triangle out of balance.

Background/Aims: Catecholamines prevent hypothermic cell death which accounts for severe tissue damage and impaired allograft function after prolonged organ preservation. Here, we identified cellular processes which govern hypothermia-mediated cell death in endothelial cells and how they are influenced by dopamine. Methods: Lactate dehydrogenase assay, intracellular ATP, reactive oxygen species and reduced thio-group measurement, intracellular calcium measurement and mitochondrial calcium staining were performed in the study. Results: Intracellular ATP was almost completely depleted within 12 hrs of hypothermic preservation in untreated human umbilical vein endothelial cells (HUVEC), while dopamine pre-treatment significantly delayed ATP depletion. 4 hrs after hypothermia a redox imbalance was observed in untreated cells, which increased with the duration of hypothermia. The redox imbalance was primarily caused by depletion of SH reduction equivalents and was significantly inhibited by dopamine. In addition, hypothermia-induced Ca2+ influx and mitochondrial Ca2+ accumulation were both prevented by dopamine. The protective effect of dopamine was abrogated by ionomycin and sodium azide and partly by oligomycin and CCCP. Conclusions: Our data demonstrated that loss of intracellular ATP, generation of a redox imbalance and accumulation of intracellular Ca2+ underlie cold preservation injury. Dopamine improves the redox balance, prevents intracellular Ca2+ accumulation and delays ATP depletion.

Modulation of chemokine production and expression of adhesion molecules in renal tubular epithelial and endothelial cells by catecholamines.

Background. The present study was conducted to investigate whether catecholamines influence the production of chemokines and adhesion molecules in proximal tubular epithelial cells (PTECs) and endothelial cells. Methods. PTECs and human umbilical vein endothelial cells (HUVECs) were stimulated with various concentrations of dopamine (DA), adrenaline (AD), or noradrenaline (NA), and the production of interleukin (IL)-8, ENA-78, and Gro-&agr; was assessed by ELISA. The influence of catecholamine pretreatment on tumor necrosis factor (TNF)-&agr;–mediated production of these chemokines and the expression of adhesion molecules was also tested. Results. In PTECs, DA inhibited the production of all three chemokines in a dose-dependent fashion. Although inhibition in ENA-78 and Gro-&agr; production was also found in HUVECs, IL-8 production was up-regulated in these cells. Increased IL-8 secretion was predominantly observed at the apical site of the cells. In AD or NA stimulated cells, the production of Gro-&agr; was increased in PTECs and decreased in HUVECs. Down-regulation in IL-8 production was also observed after AD but not after NA stimulation of both cell types. Interestingly, TNF-&agr;–mediated up-regulation in intercellular adhesion molecule 1, vascular cell adhesion molecule (VCAM), and E-selectin was delayed in DA-pretreated HUVECs but not in PTECs. The influence of DA, but not AD or NA, on chemokine production was completely prevented by the addition of N-acetylcysteine. Conclusions. This study demonstrates that catecholamines differentially influence chemokine production and indicates that DA may have anti-inflammatory properties because it delays the expression of adhesion molecules and inhibits the production of chemokines in PTECs and endothelial cells under basal and inflammatory conditions.

Atorvastatin donor pretreatment prevents ischemia/ reperfusion injury in renal transplantation in rats : Possible role for aldose-reductase inhibition

Background. The aim of the present study was to evaluate the effect of donor pretreatment with atorvastatin on ischemia/reperfusion (I/R) injury in renal transplantation in rats. Methods. Donor rats were pretreated orally with atorvastatin or vehicle 2 days prior to explantation. Kidneys were stored for 24 hr at 4°C in University of Wisconsin solution and transplanted into isogeneic or allogeneic recipients. Results. Donor treatment with atorvastatin improved initial graft function, reduced renal inflammation, and the number of TUNEL-positive cells in renal tissue after prolonged cold storage and isogeneic transplantation. In the allogeneic transplantation model, donor treatment with atorvastatin reduced renal inflammation in grafts harvested after 5 days, but no improvement of long-term graft survival (24 weeks) could be observed. A genome wide gene expression profile of donor kidneys from atorvastatin treated or vehicle treated rats revealed a fivefold downregulation of aldose reductase in all atorvastatin treated animals (P<0.01). Donor treatment with an aldose-reductase inhibitor improved kidney function and reduced renal inflammation after prolonged cold storage and isogeneic transplantation. Conclusion. Our data suggest that downregulation of aldose reductase in renal tissue might underlie the protective effect of donor atorvastatin treatment. Donor pretreatment with a statin or an aldose reductase inhibitor could offer a new treatment strategy to prevent transplantation associated tissue injury.