High levels of donor CCL2/MCP-1 predict graft-related complications and poor graft survival after kidney-pancreas transplantation

In this study we analyzed the role of CCL2, a member of the chemokine family, in early graft damage. Using simultaneous kidney-pancreas transplantation (SPK) as a model, we showed that brain death significantly increases circulating CCL2 levels in humans. We found that in such situations, high donor CCL2 levels (measured before organ recovery and at the onset of cold preservation) correlate with increased postreperfusion release of CCL2 by both the graft and recipient throughout the week following transplantation (n = 28). In a retrospective study of 77 SPK recipients, we found a significant negative association between high donor levels of CCL2 and graft survival. Decreased survival in these patients is related to early posttransplant complications, including a higher incidence of pancreas thrombosis and delayed kidney function. Taken together our data indicate that high CCL2 levels in the donor serum predict both an increase in graft/recipient CCL2 production and poor graft survival. This suggests that the severity of the inflammatory response induced by brain death influences the posttransplant inflammatory response, independent of subsequent ischemia and reperfusion.

Self-Assembly of a Double Calix[6]arene Pseudorotaxane in Oriented Channels

A synthetic study to disclose the more appropriate manner by which two calix[6]arene units could be connected for the construction of an extended tubular structure was undertaken. As a result, a head-to-tail double calix[6]arene having the structure of an oriented nanotube that is about 2.6 nm long and 1.6 nm wide was prepared and characterized. This molecule is able to act as a wheel-type host and forms a supramolecular complex with an axle-type molecule, derived from 4,4'-bipyridinium (viologen), through very efficient self-assembly in solution. The properties of such a pseudorotaxane-type complex, which is stabilized by a combination of noncovalent interactions, were investigated in solution by UV/Vis absorption spectroscopy and voltammetric methods. These observations provide a clue about the location of the bipyridinium unit along the nanotube. In the solid state, the complex undergoes a further stage of self-assembly, thereby initiating extended oriented tubular structures. Crystallographic studies revealed that the positioning of the viologen dication in this asymmetric wheel is addressed by a complicated pattern of cooperative noncovalent intermolecular interactions that involve only one half of the host, whereas the remaining (more polar) half of the host is exploited to create long-range structural order that leads to a "secondary" structure of extended supramolecular channels that, in turn, self-assemble in the lattice, thus giving rise to a "tertiary" structure of parallel sandwiches of nanotubes.

Impact of Recipient and Donor Ages on Patient and Graft Survival After Kidney Transplantation

BACKGROUND

The purpose of the study was to evaluate the impact of donor and recipient ages on patient and graft survival after kidney transplant.

METHODS

Patients in a hospital database undergoing kidney transplant for end-stage renal disease (ESRD) during the period 1985 to May 2006 (n = 410; mean age 42 +/- 10 years; 61% men and 39% women) were divided into two groups: group A, patients of 60 years or older (6%, n = 24), and group B, those younger than 60 years (94, n = 386). In 204 patients (49.8%) the pancreas was transplanted simultaneously with the kidney.

RESULTS

Overall 1-, 3-, 5-year patient survivals were 92%, 90%, 88% in group A and 95%, 90%, 87% in group B (P = .6, NS). Overall 1-, 3-, 5-year kidney graft was 92%, 75%, 65% in group A and 92%, 84%, 79% in group B (P = .7, NS). Donors were divided into two groups: group 1, 55 years or older (15%, n = 62), versus group 2, those younger than 55 years (85%, n = 348). Overall 1-, 3-, 5-year patient survivals were 91%, 86%, 76% in group 1 and 97%, 94%, 90% in group 2 (P = .0009). Overall 1-, 3-, 5-year kidney graft survivals were 87%, 82%, 76% in group 1 and 94%, 86%, 82% in group 2 (P = .02).

CONCLUSIONS

Renal transplantation is an effective option for the treatment of ESRD in elderly patients. The overall rates of patient and kidney graft survival are comparable to those of younger patients. Donor age > or =55 years had a negative effect on patient and kidney graft survival.

Culture medium modulates proinflammatory conditions of human pancreatic islets before transplantation

A portion of transplanted islets is lost during engraftment as a result of stressful events, involving hypoxia and production of proinflammatory molecules by islets. Two of these molecules (monocyte chemoattractant protein-1, CCL2/MCP-1 and tissue factor, TF) are directly correlated with reduced graft function. We evaluated which factors reduce islet proinflammatory conditions. In particular the effects of different culture media supplemented with proteins or antioxidant agents on CCL2/MCP-1 and TF human islet release were evaluated. We observed that human islets after culture in final wash culture medium (FW) significantly decreased CCL2/MCP-1 release and TF production compared with CMRL and M199. These effects were independent from the type of protein added to the media (human serum, human albumin, fetal calf serum). Glutathione in FW further decreased CCL2/MCP-1 in a dose-dependent manner. Culture conditions can modulate the proinflammatory state of islets, and could be used in clinical islet transplantation to reduce inflammation during engraftment.

Rapamycin induces a caspase-independent cell death in human monocytes

The immunosuppressive activity of rapamycin (RAPA) and its efficacy as an anti-rejection agent in organ transplantation have been ascribed principally to its anti-proliferative effects on T cells, while the activity on monocytes is partially unknown. In vitro, RAPA reduced monocyte survival by inducing a caspase-independent cell death. RAPA-induced monocyte cell death (RAPA-CD) was impeded by activation of granulocyte macrophage-colony stimulating factor family receptors or toll-like receptor 4, and by exposure to inflammatory cytokines. In vivo, in patients who received RAPA monotherapy as part of pre-conditioning for islet transplantation, RAPA affected survival of myeloid lineage cells. In the peripheral blood, CD33(+) and CD14(+) cells decreased, whereas lymphocytes appeared unaffected. In the bone marrow, myeloid precursors such as CD15(+) and CD15(+)/CD16(+) were selectively and significantly decreased, but no major cytotoxic effects were observed. The RAPA-CD suggests a dependence of monocytes on mammalian target of RAPA pathways for nutrient usage, and this feature implies that RAPA could be selectively useful as a treatment to reduce monocytes or myeloid cells in conditions where these cells negatively affect patient, suggesting a potential anti-inflammatory action of this drug.

Triple Arterial Reconstruction Improves Vascularization of Whole Pancreas for Transplantation

We assessed the effect on duodenal stump vascular supply of reconstruction of the gastroduodenal artery performed before pancreas transplantation. The median pancreas graft and patient survival times were 144 and 72 months for cases with or without gastrointestinal bleeding. Transmural blood flow values were significantly different between the donor duodenal stump and the recipient anastomosed jejunum (P < .01). The rate of gastrointestinal bleeding was lower in patients who received a pancreatic graft with back-table reconstruction of the gastroduodenal artery (P = .005).

Cardiovascular benefits of simultaneous pancreas-kidney transplant versus kidney alone transplant in diabetic patients

The aim of our study was to demonstrate the cardiovascular benefits of simultaneous pancreas-kidney transplantation when compared to kidney-alone transplants in diabetic recipients.

PATIENTS AND METHODS

A total of 386 renal transplants were performed from 1985 to 2004, including 262 (68%) in diabetic recipients and 124 (32%) in nondiabetics. Among the former group, 200 kidneys were transplanted simultaneously to the pancreatic graft (KP group) and 62 were kidney-alone transplants (KA group). The mean time on dialysis was 31 +/- 20 months (range 0-126 months). The duration of diabetes was 24 +/- 7 years (range 5-51 years). Ninety-nine percent of the patients were on renal replacement therapy (79% on hemodialysis and 20% on peritoneal dialysis).

RESULTS

Among 262 patients, 28 (11%) died due to a cardiovascular event, which was higher among KA patients compared with the KP group (P = .004). Overall patient survival was significantly higher in the KP group when compared with the KA group (log-rank: P = .0004). Patient survivals were 80% and 70% versus 70% and 40% at 5 and 10 years in the KP and KA groups, respectively. Kidney graft survivals were 81% and 60% versus 63% and 26% at 5 and 10 years in the KP and KA groups, respectively. Pancreas graft survival was 70% and 50% at 5 and 10 years, respectively.

CONCLUSIONS

This clinical evaluation, even if retrospective, confirmed that simultaneous pancreas-kidney transplantation has a protective effect against cardiovascular mortality in diabetic recipients affected by end-stage renal disease.

Completing the uric acid degradation pathway through phylogenetic comparison of whole genomes

Mammals that degrade uric acid are not affected by gout or urate kidney stones. It is not fully understood how they convert uric acid into the much more soluble allantoin. Until recently, it had long been thought that urate oxidase was the only enzyme responsible for this conversion. However, detailed studies of the mechanism and regiochemistry of urate oxidation have called this assumption into question, suggesting the existence of other distinct enzymatic activities. Through phylogenetic genome comparison, we identify here two genes that share with urate oxidase a common history of loss or gain events. We show that the two proteins encoded by mouse genes catalyze two consecutive steps following urate oxidation to 5-hydroxyisourate (HIU): hydrolysis of HIU to give 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and decarboxylation of OHCU to give S-(+)-allantoin. Urate oxidation produces racemic allantoin on a time scale of hours, whereas the full enzymatic complement produces dextrorotatory allantoin on a time scale of seconds. The use of these enzymes in association with urate oxidase could improve the therapy of hyperuricemia.

Reduced intrahepatic fat content is associated with increased whole-body lipid oxidation in patients with type 1 diabetes

AIMS/HYPOTHESIS

Insulin resistance may be associated with ectopic fat accumulation potentially determined by reduced lipid oxidation. In patients with type 1 diabetes peripheral insulin resistance is associated with higher intramyocellular lipid content. We assessed whether these patients are also characterised by intrahepatic fat accumulation and abnormal fat oxidation.

METHODS

Nineteen patients with type 1 diabetes (6 women, 13 men, age 35+/-7 years, BMI 23+/-3 kg/m2), HbA1c 8.7+/-1.4%) and 19 healthy matched individuals were studied by (1) euglycaemic-hyperinsulinaemic clamp combined with [6,6-2H2]glucose infusion to assess whole-body glucose metabolism; (2) indirect calorimetry to assess glucose and lipid oxidation; and (3) localised 1H-magnetic resonance spectroscopy of the liver to assess intrahepatic fat content.

RESULTS

Patients with type 1 diabetes showed a reduced insulin-stimulated metabolic clearance rate of glucose (4.3+/-1.3 ml kg(-1) min(-1)) in comparison with normal subjects (6.0+/-1.6 ml kg(-1) min(-1); p<0.001). Endogenous glucose production was higher in diabetic patients (p=0.001) and its suppression was impaired during insulin administration (66+/-30 vs 92+/-8%; p=0.047) in comparison with normal subjects. Plasma glucagon concentrations were not different between groups. The estimated hepatic insulin concentration was lower in diabetic patients than in normal subjects (p<0.05), as was the intrahepatic fat content (1.5+/-0.7% and 2.2+/-1.0% respectively; p<0.03), the latter in association with a reduced respiratory quotient (0.74+/-0.05 vs 0.84+/-0.06; p=0.01) and increased fasting lipid oxidation (1.5+/-0.5 vs 0.8+/-0.4 mg kg(-1) min(-1); p<0.01).

CONCLUSIONS/INTERPRETATION

In patients with type 1 diabetes, insulin resistance was not associated with increased intrahepatic fat accumulation. In fact, diabetic patients had reduced intrahepatic fat content, which was associated with increased fasting lipid oxidation. The unbalanced hepatic glucagon and insulin concentrations affecting patients with type 1 diabetes may be involved in this abnormality of intrahepatic lipid metabolism.

Multivariate Analysis of Factors Affecting Patient and Graft Survival After Renal Transplant

AIM

To evaluate factors affecting patient and kidney survival after renal transplant.

PATIENT AND METHODS

Among 361 patients undergoing renal transplant: 52% (n = 189) were simultaneous with pancreas transplant (SPKT group) and 48% (n = 172), a kidney transplant alone (KT group). Out of 361 patients, 75% (n = 270) were diabetics. The patients were 220 (61%) men and 141 (39%) women of mean age 41 +/- 9 years. The mean time of dialysis was 42 +/- 21 months (range 0 to 126), and the mean duration of diabetes 24 +/- 7 years (range 5 to 51). A Cox regression analysis was done.

RESULTS

The multivariate analysis revealed that in the final model diabetes and donor age were significant predictors of kidney graft survival; moreover, diabetes and recipient age were predictors of patient survival. Overall patient survival was significantly greater among nondiabetic patients (P = .002) or in diabetic patients who received SPKT, when compared with diabetics in whom only the kidney was transplanted (P = .001).

CONCLUSIONS

Diabetes and donor age were independent prognostic factors affecting kidney graft survival after renal transplant, and recipient age and diabetes were prognostic factors affecting patient survival. Combined pancreas and kidney transplantation should be offered to patients with end-stage diabetic nephropathy.

Metabolic Assessment After Simultaneous Pancreas–Kidney Transplantation

Simultaneous pancreas-kidney (SPK) transplantation has become a standard therapy for patients with type 1 diabetes and end-stage renal disease. We analyzed metabolic data in this clinical setting under tacrolimus- versus cyclosporine microemulsion (ME)-based immunosuppressive therapy.

PATIENTS AND METHODS

We analyzed 205 patients enrolled in the Euro-SPK001 study for fasting blood glucose, fasting C peptide, glycated hemoglobin (HbA(1c)), blood lipids (total cholesterol and triglycerides), and pancreatic enzymes at regular intervals during the study. We compared blood pressure values with target levels for diabetic patients published by the European Society for Hypertension.

RESULTS

Throughout the study, HbA(1c) and fasting C peptide levels were within the normal range in the two groups. Fasting blood glucose was higher during the first 2 months posttransplant in the tacrolimus group than in the cyclosporine-ME group, but no differences were seen thereafter. From month 2 posttransplant, mean levels of total cholesterol were significantly lower among patients receiving tacrolimus than those in the cyclosporine-ME group. In addition, patients receiving cyclosporine-ME showed serologic features of mild pancreatitis with elevated blood amylase and lipase levels during the first 6 months posttransplant. The two regimens were comparable with respect to hypertension, but target levels were reached in only 50% of the patients.

CONCLUSION

Except for lipid profiles, no major differences in metabolic effects or blood pressure control were observed among SPK transplant patients receiving immunosuppression based on tacrolimus versus cyclosporine-ME. In view of the potential risk of hypertension, antihypertensive strategies should be implemented for all patients.

Islet isolation for allotransplantation: variables associated with successful islet yield and graft function

AIMS/HYPOTHESIS

Efficient islet isolation is an important prerequisite for successful clinical islet transplantation. Although progressively improved, islet yield and quality are, however, unpredictable and variable and require standardisation.

METHODS

Since 1989 we have processed 437 pancreases using the automated method. The donor characteristics, pancreas procurement, and digestion and purification procedures including a wide enzyme characterisation of these pancreases were analysed and correlated with islet yield and transplant outcome.

RESULTS

By univariate analysis, islet yield was significantly associated with donor age (r=0.16; p=0.0009), BMI (r=0.19; p=0.0004), good pancreas condition (p=0.0031) and weight (r=0.15; p=0.0056), total collagenase activity (r=0.22; p=0.0001), adjusted collagenase activity/mg (r=0.18; p=0.0002), collagenase activity/solution volume (r=0.18; p=0.0002) and neutral protease activity/solution volume (r=0.14; p=0.0029). A statistically significant contribution to the variability of islet yield in a multivariate analysis performed on donor variables was found for donor BMI (p=0.0008). In a multivariate analysis performed on pancreas variables a contribution was found for pancreas weight (p=0.0064), and for a multivariate analysis performed on digestion variables we found a contribution for digestion time (p=0.0048) and total collagenase activity (p=0.0001). Twenty-four patients with type 1 diabetes received single islet preparations from single donors. In these patients, multivariate analyses showed that the reduction in insulin requirement was significantly associated with morphological aspects of islets (p=0.0010) and that 1-month C-peptide values were associated with islet purity (p=0.0071).

CONCLUSIONS/INTERPRETATION

These data provide baseline donor, digestion and purification selection criteria for islet isolation using the automated method and indicate that the morphological aspect may be a clinically relevant measure of islets on which the decision for transplant can be based.

Long-term survival after kidney and kidney-pancreas transplantation in diabetic patients

PURPOSE

To investigate the influence of diabetes mellitus on patient and graft survival among renal versus renal-pancreatic recipients.

METHODS

Among 270 renal transplants performed from 1985 to 2002, a total of 204 (75%) were in diabetic patients and 66 (25%) in nondiabetic patients. Among the 204 diabetic patients 161 (60%) kidneys were transplanted simultaneously with a pancreatic graft (SKPT group). The overall group of patient included 164 (61%) men and 106 (39%) women with mean time on dialysis of 31 +/- 21 months (range 0 to 126 months). The mean duration of diabetes was 24 +/- 7 years (range 5 to 51 years). Ninety-nine percent of the patients were on renal replacement therapy (79% hemodialysis and 20% peritoneal dialysis).

RESULTS

The overall rejection rate was similar (NS). Both patient and kidney graft survival rates were worse in diabetics. Patient survival was 82% at 5 years among patients undergoing SKPT, 60% in diabetics receiving only a kidney, and 88% in nondiabetic transplanted patients. Kidney graft survival at 5 years was 77% in diabetics receiving SKPT, 68% in diabetics receiving a kidney alone, and 82% in nondiabetic patients. Overall patient survival was significantly greater among nondiabetics (P =.002) or in diabetics who received SKPT compared with diabetics who only had a kidney transplant (P =.001).

CONCLUSIONS

This retrospective clinical evaluation confirms that combined pancreas and kidney transplantation should be the first choice to insulin-dependent diabetes mellitus (IDDM) patients with end-stage diabetic nephropathy.

Recognition of quaternary ammonium cations by calix[4]arene derivatives supported on gold nanoparticles

Calix[4]arene derivatives supported on monolayer protected gold clusters show a remarkable enhanced binding efficiency towards quaternary ammonium salts in homogeneous solution of apolar solvents with respect to the corresponding unsupported hosts.

Islet transplantation in type 1 diabetic patients

Islet transplantation has been shown to improve overall glucose homeostasis and retard the progression of complications in type I diabetic patients. Also the percentage of recipients achieving complete insulin independence has progressively increased over recent years. An unsolved problem is whether the short-term graft function is secondary to progressive islet exhaustion or to recurrent autoimmunity despite the immunosuppressive therapy. The indications for this procedure remain limited to selected type I diabetic patients. The risks of the immunosuppressive therapy are only proposed to type I diabetic recipients with uncontrolled disease, despite all efforts of the diabetologist and the patient (brittle diabetes), or with a poor quality of life due to unawareness hypoglycemia or severe chronic and progressive complications.

[Simultaneous pancreas-kidney transplantation: a single center experience on 148 cases]

AIM

To evaluate the outcome of simultaneous pancreas transplantation (SKPT) focusing on the surgical technique applied.

PATIENTS AND METHODS

One hundred forty-eight patients were submitted to SKPT 33 with segmental pancreas with duct occlusion (from 1985 to 1990), 77 with whole pancreas with bladder diversion (from 1990 to 1998) and 38 whole pancreas with enteric diversion (29 with systemic and 9 with portal drainage) (from 1998 to December 2001).

RESULTS

Patient survival was 92%, 82%, 63% at 1, 5, and 10 years respectively. Kidney survival was 87%, 75%, and 48% at 1, 5, 10 years. Pancreas graft survival was 71%, 58%, and 46% at 1, 5, 10 years. In the enteric diversion group patient, kidney, pancreas survival at one year was 93%, 92%, and 75%. A positive effect on patient survival was evident in enteric diversion versus duct occlusion group (p = 0.03), but not versus bladder diversion group and on pancreas graft survival in enteric diversion versus duct occlusion group (p < 0.01).

CONCLUSIONS

These data suggest that SKPT has become a successful intervention for patients with type I diabetes and end stage renal disease. Reasons for these improvements include improved donor and patient selection criteria, refinements in surgical technique and better immunosuppression.