Posttransplant diabetes mellitus in renal allograft recipients: A prospective multicenter study at 2 years

The purpose of this study was to investigate the incidence and risk factors for the development of diabetes mellitus after kidney transplantation (PTDM). A total of 1783 nondiabetic renal allograft recipients transplanted from January 2000 to December 2002 were included. Diabetes was diagnosed following American Diabetes Association criteria. While 1276 patients were treated with tacrolimus (Tac), mycophenolate mofetil (MMF), and steroids, 507 patients received cyclosporine-ME (CsA), MMF, and steroids. PTDM incidence at 6, 12, and 24 months was 14.2%, 12.8%, and 13.3%, respectively. Cumulative incidence during the follow-up was 21.6%. Only 121 of the diabetic patients (47.6%) at 6 months remained diabetic at 24 months. Furthermore, 60 patients of 116 patients on insulin at 6 months (51.7%) remained on treatment at 24 months. The cumulative incidence of PTDM was similar in the two immunosuppressive treatments (19.7% on CsA-MMF vs 22.3% on Tac-MMF; P = NS). However, at 24 months, 14 of 50 diabetic patients on CsA-MMF (28%) and 74 of 161 patients on Tac-MMF (45.9%) were on insulin treatment (P < .05). By Cox regression analysis, age older than 60 years (RR 1.61; 95%CI 1.28-2.04; P < .001), body mass index (BMI) > 30 kg/m2 at transplantation (RR 1.66; 95%CI 1.27-2.16; P < .001), and immunosuppression with Tac (RR 1.30; 95%CI 1.02-1-66; P = .033) were associated with PTDM. In conclusions, the incidence of PTDM at 24 months in immunosuppressive protocols including MMF is about 22%, and it is associated with older age, increased BMI, and immnunosuppression with Tac.

[Acute rejection of kidney transplant is associated with induction of replicative senescence in CD8+ T lymphocytes]

Acute renal rejection repeatedly activates immunocompromised CD8 + T cells. Maintained activation of CD8 + T cells can induce a process of replicative senescence. In the present study, we will evaluate in CD8 lymphocytes from patients undergoing acute renal rejection characteristics of replicative senescence such as: a) low expression of CD28 molecule; b) telomere shortening and c) increase production of proinflammatory cytokines. The study was carried out in CD8 + T cells from 14 patients transplanted without clinical evidences of acute renal rejection, 14 patients kidney transplanted with clinical and anatomopathological evidences of acute renal rejection, 8 healthy controls. The results shown that in peripheral blood and renal biopsy of patients with acute renal rejection there is a significant increment of the population of T cells CD28-CD8+, with short telomere length, as compared with healthy controls and patients without acute renal rejection. The presence of senescent cells was associated with high levels of IL-10 and IFN-Y in plasma and urine. In conclusion our study suggest that the CD8 + T cells of patients with acute renal rejection suffer a process of replicative senescence.

Chilaiditi syndrome associated with transverse colon volvulus: first report in a paediatric patient and review of the literature

A hepatodiaphragmatic interposition of the colon, known as Chilaiditi's sign, is usually discovered by chance during the study of another event, given that its presentation is normally asymptomatic. When this finding is accompanied by clinical symptoms, either intermittent or persistent, it is known as Chilaiditi syndrome. It may be associated with intestinal obstruction due to twisting. The association of Chilaiditi syndrome and transverse colon volvulus is exceptional. To date only three cases have been reported, all in adult males. Among the common predisposing factors were anatomical alterations of the intestine such as elongation of the colon and a history of prior abdominal surgery. The clinical symptoms were due to the intestinal obstruction. We present the first description in the paediatric population of an association of transverse colon volvulus and Chilaiditi syndrome whose predisposing factors, clinical symptoms and treatment differed from those reported in the non-paediatric cases published to date.

Comparison between a two-drug regimen with tacrolimus and steroids and a triple one with azathioprine in kidney transplantation: results of a European trial with 3-year follow up

This study was designed to assess the efficacy and safety of two immunosuppressant regimens in kidney transplantation based on the administration of tacrolimus-one of them with tacrolimus, azathioprine, and corticosteroids (n=239) and the other with tacrolimus, and corticosteroids (n=236). After completing the initial 3-month study, the patients remaining in the study (197 and 195, respectively) were assessed for 3 years. The incidence of acute rejection (AR) episodes treated during this period was 28.8% with dual-drug therapy and 29.7% with triple-drug therapy. Late AR: episodes between 4 and 36 months were scarce (3.3% in dual and 4.2% in triple therapy). Chronic rejection incidence was 7.7% and 8.9%, respectively. The patients who experienced AR episodes during the first 3 months developed chronic rejection more frequently than those who did not suffer AR. Patient survival at 3 years was 95% vs 95.6%, and graft survival was 86.6% vs 86.5% (NS). Doses and blood levels of tacrolimus were similar in the two groups. Adverse effects were similar among both treatment groups. Median SCr was 123.8 micromol/L vs 114.9 micromol/L in patients who did experience AR: 145.9 micromol/L vs 132.6 micromol/L in those with early AR; and 194.5 micromol/L vs 152 micromol/L in those who presented with late AR. Need for de novo posttransplant insulin was 4.2% in the dual-drug group and 3.8% in the triple-drug cohort. These results demonstrate that, after 3 years of follow up, there were similar efficacy data among the dual- and triple-drug regimens. Thus, addition of azathioprine does not contribute any advantage in the middle term.

Tacrolimus is highly effective in both dual and triple therapy regimens following renal transplantation. Spanish and Italian Tacrolimus Study Group

This open, multicenter, randomized, parallel-group study evaluated the efficacy and safety of tacrolimus-based dual and triple therapy regimens. For this 3-month study (with 12-month follow up), 491 adult renal transplant patients were randomized and received either dual therapy (tacrolimus/corticosteroids; 246 patients) or triple therapy (tacrolimus/corticosteroids/azathioprine; 245 patients). Patient survival rates at months 3 and 12 were 99.2 (dual) vs 99.6% (triple) and 97.8 vs 98.7%, respectively. Graft survival rates at months 3 and 12 were 94.1 (dual) vs 95.4% (triple) and 92.8 vs 93.3%, respectively. After 3 months, the incidences of treated acute rejection were 28.8 (dual) and 29.7% (triple); and 7.6 (dual) and 5.4% (triple) for corticosteroid-resistant acute rejections. Between months 4 and 12, three new first rejections were reported, (dual: 2, triple: 1). For leukopenia (1.3 vs 11.7%; P < 0.001) and anemia (14.8 vs 23.0%, P = 0.026), significantly higher incidences were reported in the triple therapy group. The incidence of de novo insulin-dependent diabetes was 5.6 (dual) and 4.0% (triple) at month 3. In terms of efficacy, no difference between the treatment groups was observed.

Age-Related differences on aluminium mobilization by chelating agents in aluminium-loaded uraemic rats

The efficacy of deferoxamine, deferiprone, and a combination of these chelating agents in the mobilization and promotion of aluminium (Al) excretion was compared in two age groups of uraemic rats which had previously received Al nitrate nonahydrate intraperitoneally in a daily dose of 45 mg/kg for 5 weeks. At the end of the period of Al exposure, Al-loaded rats of each age (young and adult) group were given one of the following treatments for 5 days: 0.90 mmol/kg/ day of deferoxamine (subcutaneously), 0.90 mmol/kg/day of deferiprone (orally), and 0.45 mmol/kg/day of deferoxamine (subcutaneously) plus 0.45 mmol/kg/day of deferiprone (orally). Control rats were given 0.9% saline (subcutaneously) and deionized water (orally). Total urines were collected 24 hr after each chelator administration. Although young rats treated with deferoxamine, deferiprone, or deferoxamine plus deferiprone showed significant increases in the total amount of Al excreted into urine during 5 consecutive days, the effect of combined administration of deferoxamine and deferiprone was lower than that caused by deferoxamine or deferiprone only. On the other hand, after administration of deferoxamine and deferiprone, a significant reduction of Al was noted only in the liver of young rats, while no significant effects of the chelators were seen in any of the examined tissues of adult animals. The results of the current study show that a combined therapy with deferoxamine and deferiprone (at half-doses of each drug) can also be effective in mobilizing Al from the body of Al-loaded uraemic rats.

Inhibition of hepatic cell nuclear DNA fragmentation by zinc in carbon tetrachloride-treated rats

BACKGROUND/AIMS

The aims of this study were to ascertain: 1) whether hepatic cell DNA fragmentation is increased in rats with early stages of liver disease induced by carbon tetrachloride; 2) whether the inhibition of DNA cleavage is involved in the hepatoprotective effects of zinc; and 3) if relationships exist between DNA fragmentation and the onset of fibrosis in this experimental model.

METHODS

Twenty-one treated rats and 23 controls were divided into two groups to receive either a standard diet or one supplemented with zinc. All the animals were sacrificed 1 week later for histological and biochemical assessments, which included a DNA fragmentation index, hepatic zinc and metallothionein concentrations, fibrosis measured by hepatic hydroxyproline concentration and plasma alanine aminotransferase activity.

RESULTS

Hepatic cell DNA fragmentation was increased in rats with early hepatic fibrosis and the increase was independent of hepatocytolysis, as measured by alanine aminotransferase activity. Oral zinc administration inhibited hepatic cell DNA fragmentation in the treated rats and was proportional to the hepatic concentration of the metal. The mechanism of the zinc-mediated decrease in DNA cleavage was related to an increase in the hepatic metallothionein concentration. Hepatic cell DNA fragmentation was related to hydroxyproline concentration.

CONCLUSIONS

Our results suggest that apoptosis may be involved in the early transformations occurring in the liver and which can lead to the initiation of cirrhosis. As such, the potential therapeutic use of zinc supplementation would warrant further investigation.

Cardiovascular response to hemodialysis: the effects of uremia and dialysate buffer

Cardiovascular instability continues to be one of the primary clinical problems in hemodialysis. Acetate buffer in dialysate is one of the factors that may induce hypotension. Since uremia may have a direct effect on the regulation of the cardiovascular system, the present study was designed to investigate the separate effects of uremia and acetate hemodialysis on blood pressure in anesthesized dogs, as well as the hemodynamic parameters determined by invasive cardiovascular monitoring. Animals were separated into four groups: (1) group I, hemodialysis with acetate in controls; (2) group II, hemodialysis with acetate in uremic dogs; (3) group III, hemodialysis with bicarbonate in controls; and (4) group IV, hemodialysis with bicarbonate in uremic dogs. Acute uremia was induced by bilateral ureteral ligation and a 90-minute hemodialysis (acetate or bicarbonate) procedure was performed 72 hours later. The results obtained in this study show that, compared with dogs with normal renal function, acute uremia resulted in an elevation in mean arterial pressure (MAP; 178 +/- 13 vs. 115 +/- 23 mm Hg, P < 0.01), which was associated with an increase in cardiac index (CI) and left ventricular stroke work index (LVSWI). In these dogs, the pulmonary capillary wedge pressure (PCWP; preload) and the systemic vascular resistance index (SVRI; afterload) were not different than controls. In uremic dogs, hemodialysis with acetate, but not with bicarbonate, decreased the MAP to values similar to controls. The decrease in MAP induced by acetate hemodialysis in uremic dogs was associated with a decrease in SVRI and PCWP. These results suggest that in dogs with acute uremia, acetate hemodialysis (HD) decreases myocardial contractility that was previously increased by a direct effect of uremia. In controls, acetate produced a moderate decrease in MAP that was the result of a mild decrease in CI and SVR. Since PCWP was not significantly decreased after acetate HD, the decrease in CI can be attributed to a mild decrease in myocardial performance. In conclusion, this study in dogs suggests that uremia enhances myocardial contractility directly. Acetate hemodialysis reduces this elevated myocardial contractility to normal values.

Efficacy and safety of losartan in the treatment of hypertension in renal transplant recipients

Arterial hypertension, which represents a common problem in patients with renal transplant, contributes to the cardiovascular morbidity and mortality of these patients. The most usual immunosuppressive drugs (cyclosporine and FK-506) collaborate on the development of hypertension. Calcium channel blockers are the most habitually used antihypertensive drugs in this population, although its long-term hemodimamycs effects could be deleterious especially in transplanted patients with chronic graft nephropathy. Losartan, a specific blocker of angiotensin II (AT1) receptors, has demonstrated a potent antihypertensive effect with a good safety and tolerance profile. The glomerular effects of losartan could be useful in transplanted patients. The present open, prospective and multicenter study evaluated the efficacy and safety of losartan in the treatment of hypertension in a group of patients with a renal transplant. Seventy-six patients with systolic blood pressure > or = 140 and/or diastolic blood pressure > or = 90 mm Hg, and/or patients on therapy with one antihypertensive drug and related side effects were included. After inclusion, therapy with losartan 50 mg/24 hr was started, discontinuing the previous antihypertensive therapy and/or therapy which caused the side effects. At four weeks, if blood pressure (BP) was not controlled, hydrochlorothiazide 25 mg or furosemide 40 mg/24 hr was added. At baseline and at weeks 2, 4, 8 and 12, the following parameters were monitored: BP, creatinine, hematocrit, hemoglobin, glucose, ions, uric acid, cholesterol, triglycerides, bilirubin, SGOT, SGPT, GGT, LDH, calcium, phosphate, alkaline phosphatase, proteinuria, and both cyclosporine and FK-506 levels in whole blood. Sixty-seven patients completed the 12-week study period. Mean blood pressure decreased from 113 +/- 10 to 102 +/- 9 mm Hg at the end of the study (P < 0.0001); 38 of the 67 patients (56.7%) who completed the study had a SBP lower than 140 mm Hg and a DBP lower than 90. These blood pressures were obtained in 30 patients on monotherapy with losartan (78.9%). Proteinuria decreased significantly at week 4 and was confirmed at week 12, especially in patients with proteinuria > or = 300 mg/24 hr. Nine patients were withdrawn during the study period for different reasons. Serum creatinine showed a slight, non-clinically significant increase at week 4, remaining stable until the end of the study. Two patients developed a mild normocytic anemia, and three others presented a mild impairment of pre-existent anemia. No interactions with cyclosporine or FK-506 were described. These results indicate that losartan is effective in reducing BP in hypertensive patients with a renal transplant. It has a good tolerance profile and does not interfere with immunosuppressive therapy.

Tacrolimus rescue therapy for cyclosporine-induced nephrotoxicity

Following renal transplantation, the long-term use of cyclosporine can cause nephrotoxicity. This small study of ten patients looks at the effects of tacrolismus rescue therapy over a 6-month period. After conversion to tacrolismus, renal function improved in seven patients, progressive graft dysfunction slowed and almost stabilized in two patients, and, in the remaining patient, deterioration continued and hemodialysis treatment was initiated at the end of the study period. A greater number of patients and a longer follow up are necessary to confirm these initially impressive results.

Ofuji's papuloerythroderma following choledocholithiasis with secondary sepsis: complete resolution with surgery

We describe a case of Ofuji's papuloerythroderma (PE) in a 72-year-old man with biliary sepsis induced by choledocholithiasis. The PE disappeared completely after surgery with no relapse. This aetiology for PE does not appear to have been described previously, while its resolution after treatment of the primary process supports the idea that it may be a reactive disorder of multifactorial origin.

Glomerular and vascular tissues do not down-regulate nitric oxide synthesis during protracted endotoxemia

Down-regulation of cytokines is implicated as an important component of the phenomenon of tolerance to bacterial products in humans and animals. Since many effects of endotoxin and cytokines are mediated by nitric oxide, this study was designed to evaluate in vivo the L-arginine:NO pathway in endotoxin tolerance. Sublethal injections of E. coli lipopolysaccharide (LPS, 1 mg/kg body wt, i.p.) were given to rats daily for five days. Blood levels of NO2-/NO3-, stable metabolites of nitric oxide (NO), significantly increased on day 1 (baseline, 89.64 +/- 40, day 1, 260.32 +/- 36 nmol/ml; P < 0.05) but returned to baseline levels on day 5 (77.60 +/- 5 nmol/ml). However, urinary NO2-/NO3- remained significantly elevated several-fold throughout the study period (baseline, 121.25 +/- 11.4, day 1, 899.35 +/- 15.8, day 5, 250.23 +/- 21.4 nmol/hr/100 g body wt). Glomeruli and aortae obtained from these rats showed increased NO production that was maintained at similar levels even at day 5 (glomeruli: control, 0.01 +/- 0.0, day 1, 22.4 +/- 0.3, and day 5, 22.0 +/- 2.5, P < 0.05 vs. control; aortae; control, 0.01 +/- 0.0, day 1, 4.3 +/- 2.2, and day 5, 5.4 +/- 1.0 nmol/hr/mg protein, P < 0.05 vs. control, respectively); this further increased significantly in response to in vitro LPS challenge. However, peritoneal macrophages, liver and spleen showed an initial increase in NO production that decreased significantly by the fifth day of LPS and could not be further stimulated by in vitro LPS challenge. Thus, in vivo NO synthesis is down-regulated during protracted LPS. Our results show that the process is relatively specific to the liver, spleen and macrophages, and is qualitatively and quantitatively different in vascular tissues such as aortae and glomeruli.

Pathophysiology of the vascular wall: the role of nitric oxide in renal disease

Nitric oxide (NO) is formed in the endothelium by the constitutive enzyme NO synthase from the substrate amino acid L-arginine. As an endogenous vasodilator it contributes to renal arteriolar tone and modulates relaxation of the mesangium, thus contributing to regulation of glomerular microcirculation. NO also plays a role in regulating renal sodium excretion and renin release. It has antiplatelet and antithrombogenic effects and thus helps prevent thrombosis within the glomerular capillaries. In sepsis and sepsis-related syndromes, NO has a renoprotective role in that it aids in maintaining renal vasodilation and inhibiting platelet adhesion and aggregation. More knowledge of these effects may lead to the design of therapeutic interventions for preventing glomerular injury.

Four-week oral toxicity study of 1,2-dimethyl-3-hydroxypyrid-4-one (L1) in uremic rats

A short-term oral toxicity study of 1,2-dimethyl-3-hydroxypyrid-4-one (L1), a promising oral chelating agent for the treatment of iron and aluminum overload, was carried out in uremic rats. L1 was administered to male uremic rats by gastric intubation at 0, 20, 40, 80 or 160 mg/kg/d for 4 w. Body weight and food and fluid intake were monitored daily. Complete hematologic examinations, serum biochemical parameter determinations and histological examinations were carried out. Although body weight gain was significantly reduced at 80 and 160 mg/kg/d, there were no effects of L1 on food and fluid consumption. There were no significant differences between controls and L1-treated groups in most of the hematological and biochemical parameters analyzed. No significant dose-dependent changes in relative organ weights were noted. The non-observed-adverse-effect level (NOAEL) for L1 in uremic rats was 40 mg/kg/d. According to the results of this study, uremia did not increase the toxic effects of L1.

The pressor effect of recombinant human erythropoietin is not due to decreased activity of the endogenous nitric oxide system

In a subset of dialysis patients, erythropoietin (rHuEpo) treatment exacerbates hypertension. The mechanism of this pressor effect is unknown; however, it has been suggested that decreased endogenous nitric oxide (NO) activity may play a role. To explore this hypothesis, Sprague-Dawley rats were given rHuEpo (150 U/kg s.c. three times per week) or corresponding vehicle. Blood pressure, haematocrit, and urinary excretion of the stable NO metabolites, nitrite (NO2) and nitrate (NO3), were determined at baseline and 3 weeks. After 3 weeks of rHuEpo treatment there was a significant increase in blood pressure and haematocrit, while in vehicle-treated rats blood pressure and haematocrit remained at basal levels. Urinary excretion of NO2+NO3 increased compared to basal in rHuEpo, but not vehicle rats. Thus in normal rats rHuEpo does have a significant pressor effect, but this is not associated with decreased activity of the endogenous NO system. Thus decreased endogenous NO activity is not responsible for rHuEpo-associated hypertension. These data further suggest that endogenous NO activity is increased in rHuEpo-treated rats, perhaps as a counter-regulatory mechanism that limits the pressor effect. Whether this mechanism is active in the setting of rHuEpo-treated chronic renal failure in humans is unknown.

Comparative aluminium mobilizing actions of several chelators in aluminium-loaded uraemic rats

The relative effectiveness of deferoxamine (DFO), 1,2-dimethyl-1,3-hydroxypyrid-4-one (L1), and citric and succinic acids in mobilizing and promoting excretion of aluminium (Al) were compared in female uraemic rats which had previously received aluminium nitrate nonahydrate i.p. in a daily dose of 45 mg kg-1 for 3 weeks (5 days/week). Chelators were administered s.c. at doses equal to one-eighth of their respective LD50 for five days. L1 was also given p.o. in doses of 200 mg kg-1 day-1. Total urines were collected 24 h after each chelator administration. Total urinary Al excreted over the 5-day period, expressed as mg kg-1, were: controls, 3.4; DFO-treated, 4.5 (P < 0.05); citric acid-treated, 3.7; and succinic acid-treated, 2.7. Although the daily amounts of Al excreted into urine by L1-treated rats were significantly higher (P < 0.001) than those of the controls, most animals died during the period of treatment. Measurements of Al in selected tissues 24 h after the last administration of each chelator revealed that none of the compounds significantly altered the Al concentration in bone, kidney, and brain, whereas only DFO and succinic acid significantly reduced the levels of Al in spleen. Moreover, L1 (given s.c. or p.o.) and citric acid treatment led to a significant reduction in the liver Al burden. These results indicate the need for further investigations to determine the toxicity and the therapeutical safety margins of L1.

Endotoxin-induced pulmonary dysfunction is prevented by C1-esterase inhibitor

In septic shock, hypotension, disseminated intravascular coagulation, and neutrophil activation are related to the activation of the blood coagulation contact system. This study evaluates in dogs the effect of the C1-esterase inhibitor (C1-INH), a main inhibitor of the blood coagulation contact system, on the cardiovascular and respiratory dysfunction associated with endotoxic shock. Two groups were included: controls, which received Escherichia coli endotoxin, and a C1-INH group in which C1-INH was infused before E. coli endotoxin administration. In both groups, endotoxin produced hypodynamic shock; however, the decrease in the systolic index and the ventricular systolic work indexes were greater in controls than the C1-INH group. In controls, the arterial O2 partial pressure decreased by 30% and the alveolo-arterial O2 difference increased by 625%, these parameters remained unchanged in the C1-INH group. Hypoxemia was associated with increased intrapulmonary shunt, decreased blood coagulation contact factors, and decreased C3c. In contrast, C1-INH administration prevented endotoxin-induced hypoxemia, the increase in intrapulmonary shunt, and the decrease in blood coagulation contact factors. This study shows that, in dogs with endotoxic shock, pulmonary dysfunction is associated with an activation of the blood coagulation contact phase system. An inhibition of this system by C1-INH prevented the hypoxemia induced by endotoxic shock.