Sergio Stefoni

Pharmacokinetics for once- versus twice-daily tacrolimus formulations in de novo kidney transplantation: a randomized, open-label trial.

Tacrolimus, a cornerstone immunosuppressant, is widely available as a twice‐daily formulation (Tacrolimus BID). A once‐daily prolonged‐release formulation (Tacrolimus QD) has been developed that may improve adherence and impart long‐lasting graft protection. This study compared the pharmacokinetics (PK) of tacrolimus in de novo kidney transplant patients treated with Tacrolimus QD or Tacrolimus BID. A 6‐week, open‐label, randomized comparative study was conducted in centers in Europe and Australia. Eligible patients received Tacrolimus QD or Tacrolimus BID. PK profiles were obtained following the first tacrolimus dose (day 1), and twice under steady‐state conditions. As secondary objectives, efficacy and safety parameters were also evaluated. Sixty‐six patients completed all PK profiles (34 Tacrolimus QD, 32 Tacrolimus BID). Mean AUC0–24 of tacrolimus on day 1 was approximately 30% lower for Tacrolimus QD than Tacrolimus BID (232 and 361 ng.h/mL, respectively), but was comparable by day 4. There was a good correlation and a similar relationship between AUC0–24 and Cmin for both formulations. Efficacy and safety data were also comparable over the 6‐week period. Tacrolimus QD can be administered once daily in the morning on the basis of the same systemic exposure and therapeutic drug monitoring concept as Tacrolimus BID.

Two corticosteroid-free regimens-tacrolimus monotherapy after basiliximab administration and tacrolimus/mycophenolate mofetil-in comparison with a standard triple regimen in renal transplantation : results of the Atlas study.

Background. The side effects associated with corticosteroids have led to efforts to minimize their use in renal transplant patients. In this study we compared two corticosteroid-free tacrolimus-based regimens with a standard triple therapy. Methods. This was a 6-month, phase III, open-label, parallel-group, multicenter study. The total analysis set comprised 451 patients, randomized (1:1:1) to receive tacrolimus (Tac) monotherapy following basiliximab (Bas) administration (n=153), Tac/mycophenolate mofetil (MMF) (n=151), or, Tac/MMF/corticosteroids triple therapy as a control (n=147). Results. The study was completed by 91.2% (triple therapy), 94.7% (Tac/MMF), and 82.4% (Bas/Tac) of patients. Patient baseline characteristics were similar in all groups. The incidences of biopsy-proven acute rejection were 8.2% (triple therapy), 30.5% (Tac/MMF), and 26.1% (Bas/Tac), p<0.001 (multiple test for comparison with triple therapy); Bas/Tac vs. Tac/MMF, p=ns. The incidences of corticosteroid-resistant acute rejection were 2.0%, 4.0%, and 5.2%, p=ns. Graft survival (95.9%, 96.7%, and 94.7%, p=ns) and patient survival (100%, 99.3%, and 99.3%, p=ns) were similar in all groups. Median serum creatinine at month 6 was 123.0 &mgr;mol/L (triple therapy), 134.7 &mgr;mol/L (Tac/MMF) and 135.8 &mgr;mol/L (Bas/Tac). The overall safety profiles were similar; differences (p<0.05) were reported for anaemia (24.5% vs. 12.6% vs. 14.5%), diarrhoea (12.9% vs. 17.9% vs. 5.9%), and leukopenia (7.5% vs. 18.5% vs. 5.9%) for the triple therapy, Tac/MMF, and Bas/Tac group, respectively. The incidences of new-onset diabetes mellitus were 4.6%, 7.1%, and 1.4%, respectively. Conclusion. Corticosteroid-free immunosuppression was feasible with the Bas/Tac and the Tac/MMF regimens. Both corticosteroid-free regimens were equally effective in preventing acute rejection, with the Bas/Tac therapy offering some safety benefits.

Restless legs syndrome enhances cardiovascular risk and mortality in patients with end-stage kidney disease undergoing long-term haemodialysis treatment

BACKGROUND Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterized by paraesthesia, dysaesthesia and the irresistible urge to move the legs especially at night. Its prevalence is much higher among dialysis patients at 12 to 62% compared to 3 to 9% in the general population. Here, we investigated the association between RLS and cardiovascular events risk and laboratory parameters in end-stage kidney disease (ESKD) patients on dialysis. METHODS One hundred ESKD patients undergoing haemodialysis were enrolled in an 18-month prospective observational study. The main outcomes were the associations of RLS with new cardiovascular events and cardiovascular mortality. RESULTS RLS affected 31% of the study population. It was associated with female gender, gradual reduction in residual diuresis, lower albumin (P = 0.039) and inflammation, but not the dialysis parameters Kt/V and URR. During observation, 47% of patients experienced new cardiovascular events (64.5% with and 39.1% without RLS; P = 0.019). New cardiovascular events increased with severity of RLS [intermittent (I-RLS) vs continuous (C-RLS)]. Mortality was 20.0% in all patients, 32.3% in those with and 14.5% in patients without RLS (P = 0.04). In patients with I-RLS, mortality was 23.8% compared to 55.6% in patients with C-RLS (P = 0.014). Multivariate analysis confirmed the relationship between RLS and mortality. CONCLUSIONS This study confirmed the high prevalence of RLS among dialysis patients and the associations between the severity of RLS and the risk of new cardiovascular events and higher short-term mortality.

Increased expression of p16(INK4a) and p27(Kip1) cyclin-dependent kinase inhibitor genes in aging human kidney and chronic allograft nephropathy

BACKGROUND The goal of the current study was to examine the potential value of p16(INK4a) and p27(Kip1) cyclin-dependent kinase inhibitor (CDKI) genes in the process of human kidney aging in vivo, and in the development of chronic allograft nephropathy (CAN). METHODS Expression of p16(INK4a) and p27(Kip1) CDKI genes was evaluated and compared in 20 normal human kidney tissues of different ages (range, 21 to 80 years) and in 9 chronically rejected kidney grafts. Age dependency of marker expression was analyzed by the Pearson correlation and linear regression. RESULTS Expression of p16 in cortical tubular (CTS) and interstitial (CIS) cells of normal kidney was age dependent (correlation coefficients: 0.608 and 0.726, 95% confidence interval [CI]: 0.227 to 0.828 and 0.417 to 0.884, respectively). Cortical tubular expression of p27 was also correlated with increasing age (0.672, 95% CI: 0.327 to 0.859). Linear regression analyses confirmed the linearity of marker relationship with age (coefficient of determination R(2):0.370, 0.452, and 0.527 for CIS p16, CTS p27, and CTS p16, respectively). The mean chronological and predicted graft ages (53 +/- 21 and 76 +/- 8.9 years, respectively) were significantly different (P = 0.0126). The glomeruli, tubules, and interstitial cells of rejected grafts expressed significantly higher levels of p16 and p27 than normal kidneys. Expression of p16 in glomerular and cortical interstitial cells was higher in grade 3 of CAN than in grade 2 (P = 0.013 and 0.004, respectively). CONCLUSION The results of the current study show that expression of p16(INK4a) and p27(Kip1) CDKI genes is increased in cortical cells of the aging human kidney and in chronic allograft rejection, supporting the senescence theory of CAN.

Standard heparin versus low-molecular-weight heparin. A medium-term comparison in hemodialysis.

Background: To compare standard heparin (SH) and low molecular weight heparin (LMWH) in terms of anticoagulation, platelet activation and lipid metabolism, we selected 54 patients who had been on 4-hour hemodialysis three times weekly for at least 12 months, without bleeding disorders or dyslipidemic diseases. 28 were on hemodialysis with Polysulfone low-flux, 26 were on hemodiafiltration with Polysulfone high-flux. All patients underwent EPO. Methods: During the first 18 months, we administered SH 1,500 IU on starting dialysis and 1,500 ± 500 IU in continuous intradialytic infusion per session. In the following 18 months, we administered LMWH 64.6 IU/kg on starting dialysis in a single arterious bolus. We assessed aPTT, anti-factor Xa activity, TAT and FPA, β-TG and PF4. Blood samples were taken monthly at times 0, 30, 60, 180 and 240 min, as well as 1, 4 and 20 h after dialysis end. Predialysis cholesterol, HDL, LDL, triglycerides and lipoprotein(a) were checked monthly. Results: During both LMWH and SH sessions no clotting or major bleeding complications were observed. APTT with LMWH was lower than that found with SH (p < 0.001); aFXa using LMWH was higher than when using SH (p < 0.001); TAT and FPA were lower in LMWH sessions (p < 0.01) than in SH sessions. We also detected lower β-TG (p < 0.05) and PF4 levels (p < 0.05) using LMWH than using SH. As regards lipids, we only observed a significant decrease in triglycerides after 18 months of LMWH treatment. Conclusions: Routine use of LMWH during hemodialysis affords a safe and effective alternative to SH, and causes reduced platelet activation.

Residual Renal Function and Effective Rehabilitation in Chronic Dialysis

The results of a 1-7 years follow-up of multiple processed and recorded semiquantitative parameters in 148 cases of chronic uremia on regular dialysis treatment (RDT) are reported. Patients were grouped according to different levels of residual creatinine clearance (CCr) at the beginning of treatment (0-5, 5-15, and 15-21 ml/min). Regardless of a possible return to work and reasonable quality of life, patients on RDT with 0-5 ml/min CCr invariably present a worsening in various subclinical parameters semiquantitatively evaluated (bone biopsies; nerve conduction velocity; glucose A-V, etc.). In patients with 5-15 ml/min CCr better results are found. In patients with residual CCr above 15 ml/min, impairment in several parameters is hardly evident and even after several years of dialysis may still remain minimal. These results seem of importance as far as the effective and not the apparent dialysis rehabilitation is concerned.

The presence of posttransplant HLA-specific IgG antibodies detected by enzyme-linked immunosorbent assay correlates with specific rejection pathologies.

Posttransplant monitoring of anti-HLA antibodies with routine techniques gives unsatisfactory results due to a variety of technical limitations. We investigated how a new alternative technique correlates with posttransplant clinical events. A total of 313 nonselected serum samples from 136 patients were screened by an ELISA utilizing captured soluble HLA class I antigens. We observed the absence of anti-HLA antibody production in acute rejection cases responding to standard antirejection therapy. On the other hand, we showed a clear presence of these antibodies in acute rejection episodes not responding to standard therapy (P<0.0001) and in chronic rejection (P<0.001). We conclude that routine posttransplant monitoring by ELISA offers early risk assessment that is crucial for proper immunosuppression and for antirejection therapy choice.

Long-Term Patient and Renal Prognosis in Acute Renal Failure

A long-term clinicomorphological study in 227 patients with acute renal failure due to intrinsic renal damage shows the clinical value of renal biopsy for assessing treatment and predicting prognosis. Early morphological diagnosis enables appropriate therapeutic measures, which play their part in patient survival and renal survival. Present long-term results show that 5 years after the acute episode, chronic renal failure may be expected to occur in about 50% of cases with acute renal failure due to glomerular and vascular injuries. Tubulointerstitial lesions are associated with definitely better long-term prognosis.

Mesenchymal Stem Cells and Islet Cotransplantation in Diabetic Rats: Improved Islet Graft Revascularization and Function by Human Adipose Tissue-Derived Stem Cells Preconditioned With Natural Molecules

Hypoxia plays an important role in limiting the engraftment, survival, and function of intrahepatically transplanted islets. Mesenchymal stem cells (MSCs) were recently used in animal models of islet transplantation not only to reduce allograft rejection but also to promote revascularization. Among different possible origins, adipose tissue represents a novel and good source of MSCs. Moreover, the capability of adipose tissue-derived stem cells (ASCs) to improve islet graft revascularization was recently reported after hybrid transplantation in mice. Within this context, we have previously shown that hyaluronan esters of butyric and retinoic acids can significantly enhance the rescuing potential of human MSCs (hMSCs). Here we evaluated whether ex vivo preconditioning of human ASCs (hASCs) with a mixture of hyaluronic (HA), butyric (BU), and retinoic (RA) acids may result in optimization of graft revascularization after islet/stem cell intrahepatic cotransplantation in syngeneic diabetic rats. We demonstrated that hASCs exposed to the mixture of molecules are able to increase the secretion of vascular endothelial growth factor (VEGF) as well as the transcription of angiogenic genes, including VEGF, KDR (kinase insert domain receptor), and hepatocyte growth factor (HGF). Rats transplanted with islets cocultured with preconditioned hASCs exhibited a better glycemic control than rats transplanted with an equal volume of islets and control hASCs. Cotransplantation with preconditioned hASCs was also associated with enhanced islet revascularization in vivo, as highlighted by graft morphological analysis. The observed increase in islet graft revascularization and function suggests that our method of stem cell preconditioning may represent a novel strategy to remarkably improve the efficacy of islets-hMSCs cotransplantation.

Plasma exchange treatment improves prognosis of antineutrophil cytoplasmic antibody-associated crescentic glomerulonephritis: a case-control study in 26 patients from a single center.

Abstract:  Twenty‐six patients with Antineutrophil cytoplasmic antibody (ANCA)‐associated crescentic glomerulonephritis (GN) were divided into two groups according to the acute phase treatment: drug therapy consisting of steroids and oral cyclophosphamide plus a plasma exchange (PE) course (group A, 13 patients) or drug therapy alone (group B, 13 patients). Group A patients had a more severe clinical picture and higher serum creatinine than group B (12.7 ± 6.9 vs. 8.5 ± 5.3 mg%); nine patients from group A (69%) and five from group B (38%) required dialysis. At follow up (mean 35 months) all patients treated with PE were alive; four of them were in end‐stage renal disease. Among group B patients, three (23%) died in the acute phase; 6 (46%) needed renal replacement therapy at follow up. Of the dialysis‐dependent patients, five out of nine from group A were free of dialysis, while in group B two out of five patients had died, two had entered a regular dialysis treatment and one had received a cadaver graft. These data suggest  that  PE  may  significantly  improve  the  prognosis of patients with ANCA‐associated crescentic GN even if they are  not  dialysis‐dependent  at  the  time  of diagnosis.