Soluble antiapoptotic molecules and immune activation in chronic heart failure and unstable angina pectoris

Programmed myocyte cell death and activation of the immune system have been shown to occur in patients with congestive heart failure. Besides, unstable angina episodes are likely to be associated with immune activation. Our aim was to evaluate the role of changes in circulating levels of soluble Fas (sFas), suggestive of an enhanced inhibitory response to ongoing apoptosis, and soluble IL2 receptor (sIL2-R), indicative of T-lymphocyte activation, in chronic heart failure and unstable angina pectoris. Thirty patients affected by chronic heart failure (20 idiopathic and 10 ischemic cardiomyopathy) and 13 patients with unstable angina were evaluated. Twenty healthy individuals matched for age and gender were used as controls. A complete biochemical determination of indexes of myocardial damage including cardiac troponin I (cTnI) and creatine kinase (MB/CK) was performed. The results demonstrated that mean levels of sFas and sIL2-R were significantly increased in patients affected by chronic heart failure and unstable angina and were not associated with changes in renal function or with serum levels of cTnI. Highest values of sFas were found in NYHA class IV patients (IV NYHA class = 7.39 +/- 0.52 vs. controls = 1.34 +/- 0.12 ng/ml; P < 0.01) and more elevated in idiopathic than in ischemic cardiomyopathy (3.64 +/- 0.40 vs. 1.82 +/- 0.37 ng/ml; P < 0.01). Moreover, in chronic heart failure patients sFas and ejection fraction were negatively correlated (P = 0.01), whereas sFas and sIL2-R were positively correlated (P < 0.01). In unstable angina patients too, sFas and sIL2-R appeared to be correlated (P = 0.03); whereas sFas (angina group = 3.18 +/- 0.39 vs. controls = 1.34 +/- 0.12 ng/ml; P < 0.01) and sIL2-R (angina group = 0.46 +/- 0.11 vs. controls = 0.00 UI/ml; P < 0.01) were higher in angina group than in controls. In most of the cases, the increase of sFas was associated with comparable changes in sIL2-R serum levels, indicating that the activation of Fas system is strictly associated with autoimmune-inflammatory reactions. This phenomenon, both in chronic heart failure and in unstable angina, occurs in the absence of biochemical evidences of myocardial damage and seems to parallel the activation of T cell. Soluble Fas could have a role in sustaining inflammatory response and in prolonging the detrimental effects correlated with it in chronic heart failure and angina pectoris.

Modulation of humoral islet autoimmunity by pancreas allotransplantation influences allograft outcome in patients with type 1 diabetes

Pancreas transplantation in patients with type 1 diabetes presents allogeneic beta-cell autoantigens to the immune system long after the initial beta-cell destruction that leads to diabetes has occurred. The aims of this study were to determine whether re-exposure to beta-cell autoantigen through transplantation affect the humoral autoimmune response and whether its modulation correlates with graft outcome. Antibodies to the major autoantigens GAD (GADA) and protein tyrosine phosphatase IA-2 (IA-2A) were measured before and after transplantation in patients with type 1 diabetes who received pancreas and kidney allografts. In the 110 cases studied, pancreas graft survival was not significantly associated with the presence of GADA or IA-2A before transplantation. In the 75 patients with sequential follow-up samples up to 11.2 years after transplantation, autoantibodies were persistently undetectable in 44 cases (59%) and remained at stable detectable levels in 13 cases (17%). Substantial changes in antibody levels were found in 18 cases (24%), of which 13 cases (17%) had declining levels and 5 cases (7%) had marked increments after transplantation. Rising GADA and IA-2A levels in these five patients were predominantly of the IgG1 subclass, with progressive spreading of epitope reactivity. Pancreas graft function was lost 0.7-2.3 years after rising autoantibody levels in four of these five patients, and a significantly lower pancreas graft survival was found in patients with major rises in either GADA or IA-2A levels (P < 0.0001 vs. the remainder) and in patients having persistently high levels of IA-2A (P = 0.002 vs. stable antibody-negative patients). Kidney graft survival was not associated with islet autoantibody status. In conclusion, a minority of patients receiving pancreas allografts under generalized immunosuppression show a stimulation of islet autoantibody reactivity characteristic of that found in preclinical type 1 diabetes, which is almost invariably followed by graft function failure and resumption of insulin therapy.

Postabsorptive muscle protein metabolism in type 1 diabetic patients after pancreas transplantation

Insulin was shown to induce protein anabolism in vivo mainly by inhibiting proteolysis. Heterotopic pancreas transplantation in type 1 diabetes mellitus is characterized by peripheral hyperinsulinemia due to systemic rather than portal insulin delivery. Therefore, we studied the postabsorptive muscle protein metabolism in type 1 diabetic patients with or without pancreas transplantation. The forearm balance technique was performed in 9 type 1 diabetic patients on exogenous insulin treatment, in 4 type 1 diabetic patients following successful pancreas transplantation and in 6 healthy volunteers. Labelled leucine and phenylalanine were infused to quantify whole-body and muscle protein synthesis, respectively. In the postabsorptive state, whole-body protein synthesis (leucine kinetics) was similar in pancreas-transplanted patients and controls. In contrast, muscle protein synthesis tended to be less negative in pancreas-transplanted patients with respect to type 1 diabetic patients and healthy volunteers. The present data suggest that recipients with peripheral insulin delivery and chronic hyperinsulinemia are characterized by a preferential stimulation of protein synthesis in muscle rather than in the splanchnic district. When insulin was infused acutely, while maintaining euglycemia, the whole-body and muscle protein synthesis rates were approximately halved in type 1 diabetic patients with and without pancreas transplantation. We conclude that pancreas transplantation is able to normalize basal and insulin-stimulated protein metabolism. Chronic hyperinsulinemia counteract steroid-induced protein degradation by means of a mild, but persistent stimulation of muscle protein synthesis.

Influence of epinephrine and norepinephrine on intestinal villous blood flow during endotoxemia

PURPOSE

The objective of this study was to determine the effects of epinephrine and norepinephrine on mucosal villous blood flow in a normotensive model of endotoxemia.

MATERIALS AND METHODS

Thirty-two anesthetized rats were laparotomized, and a jejunal portion was exteriorized and opened by an antimesenteric incision. The jejunal segment was fixed on a plexiglass stage with the mucosal surface upward. Microcirculatory parameters were assessed by intravital videomicroscopy. The animals were randomly assigned to receive one of four treatments: infusion of Escherichia coli lipopolysaccharides (LPS, 2 mg/kg/h) without catecholamine pretreatment (LPS group); or infusion of LPS with epinephrine pretreatment (0.2 microg/kg/min, start 30 minutes before LPS infusion) (E group), or infusion of LPS with norepinephrine pretreatment (0.2 microg/kg/min, start 30 minutes before LPS infusion) (NE group). The control group did not receive either catecholamines or LPS. Mean diameter of central arterioles (D(A)) and mean erythrocyte velocity within the arterioles (V(E)) were measured 30 minutes before and at 0, 60, and 120 minutes after induction of endotoxemia. Mucosal villous blood flow was calculated from D(A) and V(E).

RESULTS

LPS infusion alone and norepinephrine plus LPS infusion led to a significant vasoconstriction of central arterioles, which was associated with a similar decrease in mucosal villous blood flow. Epinephrine infusion alone led to a vasodilation and an increase in villous blood flow within the first 30 minutes. After induction of endotoxemia, D(A) returned to baseline values and villous blood flow was as low as in the LPS and the norepinephrine group after 120 minutes.

CONCLUSION

In this experimental rat model, the catecholamines epinephrine and norepinephrine in a dosage of 0.2 microg.kg(-1).min(-1) neither diminish nor improve mucosal villous blood flow during the early phase of endotoxemia.

Insulin secretory patterns and blood glucose homeostasis after islet allotransplantation in IDDM patients: comparison with segmental- or whole-pancreas transplanted patients through a long term longitudinal study

IDDM patients undergoing islet, segmental pancreas or whole pancreas allotransplantation were studied at regular intervals after surgery (3-6 months, 1, 2, 3 and 4 years) to evaluate glycometabolic control (24 h metabolic profile, OGTT) and serum free insulin response to insulinogenic stimuli (arginine, IVGTT). Patients received the same immunosuppressive therapy, based on cyclosporin, steroids and azathioprine. Islet transplanted patients showed: 1) an early peak of insulin secretion after arginine, that was maintained up to 4 years; 2) an early, but low peak of insulin secretion after IVGTT, which was lost at 3 years, despite evidence that islets were still functioning (insulin independence with normal HbAlc levels); 3) a diabetic-like response to OGTT at 3 months, which improved at 2 years (IGT response); 4) fasting euglycemia with mild and reversible post-prandial hyperglycemia during the 24 h metabolic profile, which was maintained for up to 2 years. Insulin secretory patterns of islet transplanted patients were similar to segmental pancreas transplanted patients, and lower than whole pancreas transplanted patients. The reduced beta cell mass transplanted and the functional denervation of the transplanted islets seem to be the major determinants of this behaviour.

Effects of pancreas transplantation on late complications of diabetes and metabolic effects of pancreas and islet transplantation

Pancreas transplantation has become an accepted therapeutic approach to treat insulin-dependent diabetes mellitus, successfully restoring normoglycemia. In contrast, islet transplantation is still in the experimental phase, only a few operations having being performed world-wide. The aim of this review is to analyze the effects of pancreas transplantation on the late complications of diabetes and to report the endocrino-metabolic effects of pancreas and islet transplantation.

Spontaneous hypoglycaemia after pancreas transplantation in Type 1 diabetes mellitus

Hypoglycaemia is an important complication of insulin treatment in Type 1 diabetes mellitus (DM). Pancreas transplantation couples glucose sensing and insulin secretion, attaining a distinctive advantage over insulin treatment. We tested whether successful transplantation can avoid hypoglycaemia in Type 1 DM. Combined kidney and pancreas transplanted Type 1 DM who complied with good function criteria (KP-Tx, n = 55), and isolated kidney or liver transplanted non-diabetic subjects on the same immunosuppressive regimen (CON-Tx, n = 14), underwent 1-day metabolic profiles in the first 3 years after transplantation, sampling plasma glucose (PG) and pancreatic hormones every 2 hours. KP-Tx had lower PG than CON-Tx in the night and in the morning and higher insulin concentrations throughout the day. KP-Tx had lower PG nadirs than CON-Tx (4.40+/-0.05 vs 4.96+/-0.16 mmol l(-1), ANOVA p = 0.001). Nine per cent of KP-Tx had hypoglycaemic values (PG < or = 3.0 mmol l(-1)) in the profiles, both postprandial and postabsorptive, whereas none of CON-Tx did (p < 0.02). In conclusion, after pancreas transplantation, mild hypoglycaemia is frequent, although its clinical impact is limited. Compared to insulin treatment in Type 1 DM, pancreas transplantation improves but cannot eliminate hypoglycaemia.

Mono-oligoclonal immunoglobulin abnormalities in diabetic patients after kidney transplantation: influence of simultaneous pancreas graft

Monoclonal components (MC) are detected in as high as 30% of renal transplant recipients. Our aim was to evaluate the incidence, relevance and consequence of monoclonal components in patients with Type I (insulin-dependent) diabetes who received kidney (n = 22), kidney and whole pancreas (n = 41), kidney and segmental pancreas (n = 24) and kidney and islets (n = 12) transplants. Immuno-suppression was based on prophylactic anti-lymphocyte globulins, corticosteroids, azathioprine and cyclosporin in all patients; acute rejection was treated with steroids or anti-lymphocyte monoclonal immunoglobulin therapy (OKT3) or both. Serum immunofixation was carried out in all patients before transplantation and then after at 6 months and then yearly. Monoclonal components were detected in 81 of 99 patients (82%); 52 patients (52%) developed them within 6 months of transplantation, 15 (15%) between 6 and 12 months, with a peak prevalence at 1 year post-transplant (58%) and a decrease thereafter (10% at 9 years). Kidney recipients showed a lower incidence of monoclonal components when compared with those who received kidneys and segmental pancreases and those who received kidneys and whole pancreases. Monoclonal components were more often detected in patients who had previously experienced an acute renal rejection. Cytomegalovirus infection and acute rejection occurring in the same patient further increased the risk of developing monoclonal components, the development of which did not correlate with OKT3 treatment. A Post-transplant lymphoproliferative disorder was developed by two patients (2%), one with 5 and the other with 6 monoclonal components. In conclusion, diabetic patients receiving kidney and/or Pancreas transplantation, experiencing both cytomegalovirus infection and acute rejection, are at greatest risk of developing monoclonal components but they appear to be benign and transient; multiple band detection is a marker for the subsequent development of post-transplant lymphoproliferative disorder.

Measurement of blood flow in the main arteriole of the villi in rat small intestine with FITC-labeled erythrocytes

Changes of blood flow in the intestine occur under various pathological conditions. The mucosa of the intestine is especially sensitive to tissue damage resulting in swelling, loss of tissue integrity, and ulceration. Changes of blood supply to the mucosa may contribute to local tissue damage. Therefore, the quantification of the perfusion of the intestinal mucosa in an animal model may help to elucidate the involved pathophysiological mechanisms. In our study, autologous erythrocytes were labeled with fluorescein-isothiocyanate and used for the evaluation of erythrocyte velocity in the main arteriole of the villi in the distal part of the ileum using intravital microscopy. In addition, the arteriolar diameter was determined, and the arteriolar blood flow was calculated. Under stable cardiovascular and respiratory conditions, blood flow ranged between 6.6 +/- 0.3 and 5.9 +/- 0.3 nl/min (means +/- SEM) during the observation period of 120 min. Our results suggest that this approach is a feasible method to quantify blood flow in the main arteriole of the villi and is therefore a suitable method for further investigating changes of mucosal blood flow in acute and chronic states of bowel disease.

Improvement of glucose/insulin metabolism reduces hypertension in insulin-dependent diabetes mellitus recipients of kidney-pancreas transplantation

There is increasing evidence that metabolic disorders are common in patients with hypertension. To evaluate the relationship between glucose/insulin metabolism and hypertension in diabetes, 61 hypertensive uremic insulin-dependent diabetes mellitus patients who were recipients of kidney or pancreas/kidney transplants were studied through a 1-year follow-up. Twenty of them received a kidney (K) transplant alone, 13 received a kidney and segmental pancreas (KSP), and 28 received a kidney and whole pancreas (KWP) with duodenocystostomy. All subjects received the same immunosuppressive treatment including steroids, azathioprine, and cyclosporine. The three groups of patients were comparable for biochemical parameters, clinical characteristic, cyclosporine levels, and renal function (creatinine < 2 mg/dl). The association between hypertension and type of transplant was evaluated according a global chi-square test, then the results were broken down into two components to test for differences in hypertension between KP versus K and KWP versus KSP groups. The improvement of hypertension rate was statistically associated with KP transplant the first week after surgery, at discharge, and 1 year after transplantation (hypertension% at 1 week: KWP = 75, KSP = 23 vs. K = 70, P = 0.004; at discharge: KWP = 39, KSP = 31 vs. K = 75, P = 0.017; at 1 yr: KWP = 44, KSP = 54 vs. K = 85, P = 0.02). One year after graft fasting, free immunoreactive insulin as well as glycosylated hemoglobin and glucose levels were statistically lower in the KP groups than in the K-alone recipients. The improvement of hypertension observed in KP recipients suggests a key role of glucose and insulin metabolism on pathogenesis of diabetic hypertension.

Personality traits and metabolic control: a study in insulin-dependent diabetes mellitus patients

BACKGROUND

In the present study the authors evaluated the relationship between personality traits (according to DSM-III-R) and poor metabolic control in an adult onset insulin-dependent diabetes mellitus sample (n = 77).

METHODS

Personality traits were assessed with the Personality Diagnostic Questionnaire--Revised. Metabolic control was evaluated through glycosilated hemoglobin (HbA1c): poor metabolic control was defined as HbA1c > or = 9% (normal values < 6.0%).

RESULTS

Principal Component Analysis revealed three personality profiles: 'Cluster A/C Mixed', 'Cluster B Dependent' and 'Cluster B Aggressive'. Oneway ANCOVA, using sex as covariate, revealed a significant association (p = 0.01) only between poor metabolic control and Cluster B Dependent profile. No correlation was found between HbA1c and the other profiles.

CONCLUSION

These data suggest that a specific personality profile is associated with poor metabolic control.

Amelioration of nerve conduction velocity following simultaneous kidney/pancreas transplantation is due to the glycaemic control provided by the pancreas

Diabetic polyneuropathy is a common, disabling chronic complication of diabetes mellitus. Previous studies have suggested that combined pancreas-kidney transplantation can ameliorate nerve conduction. The relative contribution of the correction of hyperglycaemia and uraemia on nerve function is still a matter of debate. Nerve conduction velocity (NCV) was assessed before and after simultaneous pancreas and kidney transplantation, and before and after pancreas graft failure in five insulin-dependent diabetic (IDDM) patients affected by severe diabetic polyneuropathy. Sensory and motor NCV were recorded in five nerves and expressed as a cumulative index for each patient. Metabolic control was evaluated by fasting blood glucose and glycosylated haemoglobin levels. NCV index was below normal values before transplant: -3.8 +/- 0.7 (normal value: 0.89), improved 1 and 2 years after transplant: -3.1 +/- 1.3 and -2.6 +/- 0.9 (p = 0.0019), stabilised until pancreas failure and deteriorated to pre-transplant values 2 years after pancreas graft failure: -3.6 +/- 1.0 (p = 0.034). Fasting blood glucose levels worsened after pancreas graft failure. HbA1c levels, in the normal range during functioning pancreas graft (6.6 +/- 0.6%), deteriorated after its failure (8.0 +/- 0.6%, p = 0.04). Kidney function was preserved. These data support a positive effect of pancreas transplantation per se on NCV in IDDM subjects with diabetic polyneuropathy, thus demonstrating that metabolic control provided by a self-regulated source of insulin not only halts but also ameliorates nerve function, even if polyneuropathy is advanced.

Dobutamine maintains intestinal villus blood flow during normotensive endotoxemia: an intravital microscopic study in the rat

PURPOSE

The gut plays a pivotal role in sepsis. Intestinal hypoperfusion with subsequent ischemia leads to translocation of endotoxin. Dobutamine has been demonstrated to increase mesenteric blood flow during endotoxic shock; however, its effects on mucosal blood flow especially in intestinal villi is not known. Therefore, we investigated its influence on the blood flow and the arteriolar diameters in intestinal villi in a model of normotensive endotoxemia.

MATERIALS AND METHODS

Twenty-one male Wistar rats were divided into three groups: (1) control, saline; (2) endotoxin, endotoxin 1.5 mg/kg during 60 minutes; and (3) dobutamine, endotoxin 1.5 mg/kg (60 minutes) and dobutamine 2.5 micrograms/kg/min during 120 minutes. Villus blood flow and arteriolar diameters were determined at 0 minutes, 60 minutes, and 120 minutes in each group using intravital microscopy.

RESULTS

Villus blood flow was constant in the control group, significantly reduced at 120 minutes in the endotoxin group (120 minutes, 55.1 +/- 7.4%), and remained at baseline values in the dobutamine group. The arteriolar diameters remained constant in the control and the dobutamine groups, but they were significantly reduced in the endotoxin group at 120 minutes (7.8 +/- 0.2 to 6.5 +/- 0.7 micron).

CONCLUSION

Our results indicate that in rats with normotensive endotoxemia, arteriolar diameters and blood flow in intestinal villi were reduced. Dobutamine prevented arteriolar constriction and maintained villus blood flow at preendotoxemic values.

Cancer arising after pancreas and/or kidney transplantation in a series of 99 diabetic patients

OBJECTIVE

Recipients of solid organ transplants have an increased risk of developing certain types of malignancies as compared with the general population. The majority of the literature has reported on neoplasms in kidney and heart transplant recipients.

RESEARCH DESIGN AND METHODS

We describe 9 neoplasms occurring in 7 out of 73 IDDM patients after simultaneous pancreas and kidney transplantation. No cases were recorded among 26 IDDM recipients of kidney transplantation.

RESULTS

Among the neoplasms found were 2 cases of posttransplant lymphoproliferative disorder (PTLD), malignant melanoma, basal-cell and squamous-cell carcinoma of the skin in the same patient, squamous-cell carcinoma in situ of the vulva, hepatocarcinoma, small-cell lung cancer, and ductal carcinoma of the breast. Four patients died. Among immunological risk factors, over-immunosuppression for steroid-resistant kidney rejection was administered only in the 2 cases of PTLD.

CONCLUSIONS

Increased dosage of immunosuppressive agents may be necessary in some patients of prevent or treat rejection in view of their reduced survival on hemodialysis.

Islet transplantation in IDDM patients

This single-centre study investigated parameters that positively correlated with the success rate after islet allotransplantation in insulin-dependent diabetic (IDDM) patients. Twenty-one intrahepatic, fresh islet transplantations were performed in 20 IDDM patients (one patient had two transplants), after or simultaneous with kidney transplantation. The correlation between number and purity of transplanted islets and final outcome was investigated. One patient died of a cardiac arrest several hours after islet transplantation; this patient was not included in the follow-up analysis. Three patients (15%) experienced acute, irreversible, early failure of islet function, which was considered as a 'presumed rejection'. Nine patients (45%) achieved either complete insulin-independence (seven cases) or a reduction (> 50%) of exogenous insulin requirement (two cases), with sustained serum C-peptide secretion (0.89 +/- 0.04 nmol/l; duration: 21 +/- 7 months, range 2-58 months). Liver biopsy, performed 3 years after transplantation in one successful case, showed normal islets within the hepatic parenchyma. Eight cases (40%) did not show any metabolic effect of islet transplantation, with low serum C-peptide levels ('presumed function exhaustion'). Metabolic investigations performed in successful cases showed an early phase of insulin release after arginine, mild and reversible postprandial hyperglycaemia and normal HbA1c levels. Success of islet transplantation positively correlates with the number (p < 0.05) of the transplanted islets. Islet transplantation is a safe procedure, with 45% success rate, in terms of insulin-independence or relevant reductions of exogenous insulin requirement, although success can be transient.