Donor Structural and Functional Parameters Are Independent Predictors of Renal Function at 3 Months

INTRODUCTION

Epidemiological studies have shown that demographic, clinical, and histological donor characteristics influence renal function after transplantation, but whether these variables are independent predictors has not been established. The aim of this study was to evaluate the relative contribution of different donor variables on glomerular filtration rates (GFRs) at 3 months.

PATIENTS AND METHODS

We analyzed single renal transplants performed at our center from January 2000 to July 2004. Donor variables included age, gender, weight and height, cause of death, duration of brain death, serum creatinine at admission and preprocurement, history of arterial hypertension or diabetes mellitus, and smoking habit. Donor chronic damage score was calculated in preimplantation biopsies as was the addition of interstitial fibrosis, fibrous intimal thickening, and glomerulosclerosis (<10% = 0, >10% = 1). Donor and recipient GFRs were calculated according to the Cockroft-Gault formula.

RESULTS

We analyzed 202 transplants obtained from 113 deceased donors. A renal biopsy was available in 111 transplants. Recipient GFR at 3 months correlated negatively with donor age (R = -0.32, P < .01) and donor chronic damage score (R = 0.32, P < .01). GFR was lower among recipients of female versus male donors (50 +/- 15 vs 60 +/- 20 mL/min; P < .01). Donor cerebrovascular accident death (53 +/- 19 vs 63 +/- 19 mL/min; P < .01) and hypertension (48 +/- 16 vs 59 +/- 20 mL/min; P < .01) were also associated with lower GFR at 3 months. There was a positive correlation between GFR at admission, GFR preprocurement, and GFR at 3 months (R = 0.32 and R = 0.18 respectively; P < .01). Stepwise regression analysis included chronic damage score, GFR at admission, and donor gender but not donor age as independent predictors of GFR at 3 months (R = 0.50; P < .01).

CONCLUSION

Donor structural and functional parameters are independent predictors of renal function at 3 months.

New immunosuppresor strategies in the treatment of murine lupus nephritis

Renal involvement in systemic lupus erythematosus is a common complication that significantly worsens morbidity and mortality. Although treatment with corticosteroids and cytotoxic drugs may be useful in many cases, morbidity associated with these drugs and the relapsing nature of the disease make it necessary to develop new treatment strategies. Five-month old female NZB/W F1 mice were divided into the following groups: CYP group (n = 10), cyclophosphamide (CYP) 50 mg/kg intraperitoneally every 10 days; RAPA 1 group (n = 10) oral daily sirolimus (SRL), 1 mg/kg; RAPA 12 group (n = 13), oral daily SRL, 12mg/kg; FTY group (n = 10), oral fingolimod (FTY720), 2 mg/kg three times per week. An additional group of 13 non-treated mice were used as a control (control group). Follow-up was performed over four months. Animal survival, body weight, anti-DNA antibodies and proteinuria were determined. Kidneys were processed for conventional histology and immunofluorescence for IgG and complement. Total histological score (HS) was the sum of mesangial expansion, endocapillary proliferation glomerular deposits, extracapillary proliferation, interstitial infiltrates, tubular atrophy and interstitial fibrosis. All treated groups had lower proteinuria at the end of the follow-up with respect to the control group (P < 0.0001). Serum anti-DNA antibodies were appropriately controlled in RAPA 1 and CYP groups, but not in FTY or RAPA 12 groups. SRL and CYP arrested, and perhaps reversed almost all histological lesions. FTY720 ameliorated histological lesions but did not control mesangial expansion or interstitial infiltrates. SRL produces great improvement in murine lupus nephritis, while FTY720 seems a promising alternative if used in appropriate doses.

Immunosuppression for dual kidney transplantation with marginal organs: the old is better yet

Immunosuppressive protocols in dual kidney transplantation (DKT) are based on calcineurin inhibitors (CNI). We wonder whether a CNI-free immunosuppression can improve outcome in older patients receiving a DKT with marginal donor organs. Thirty-six were treated with CsA, MMF and prednisone (CsA group) and 42 with rATG, SRL, MMF and prednisone (SRL group). Incidence of delayed graft function and acute rejection was 44% and 11% in the CsA group, and 40% and 8% in the SRL group. CMV infection incidence was low in both protocols. Three-year patient survival was 89% in the CsA and 76% in the SRL group. One- and 3-year graft survival after censoring for dead with a functioning allograft was 94.2% and 94% in CsA and 95% and 90% in SRL, respectively. Renal function was similar in both groups whereas proteinuria was higher in the SRL group. Uninephrectomy due to graft thrombosis or urinary-related complications was numerically higher in the SRL (21%) than in the CsA group (8%) (p = 0.13) and it was associated with renal failure and proteinuria. In DKT, a new induction immunosuppressive protocol based on rATG, SRL, MMF and prednisone does not offer any advantage in comparison to the old CsA, MMF and prednisone.

Mycophenolate mofetil and sirolimus combination in renal transplantation

Mycophenolate mofetil (MMF) and sirolimus (SRL) are potent non-nephrotoxic xenobiotic immunosuppressants. Their complementary properties may provide the rationale for their combination in induction and maintenance regimens. MMF, a reversible inhibitor of inosin monophosphate dehydrogenase (IMPDH) acts as an antiproliferative drug; and SRL, an mTOR (mammalian target of rapamycin) inhibitor, inhibits cell proliferation driven by growth factors. Early experiences with the use of the SRL, MMF and steroid combination yielded insufficient prophylaxis of acute rejection. However, the introduction of induction therapy with mono- or polyclonal antilymphocyte antibodies to the SRL-MMF and steroid combination brings an efficient acute rejection prophylaxis, while improving renal function and/or reducing of chronic allograft nephropathy (CAN). However, adverse events related to the use of this drug combination (mainly haematological and surgery-related) result in a high rate of discontinuations in some trials, which may hamper the potential benefits of this calcineurin-inhibitor (CNI)-free strategy. Also, currently under investigation is whether in long-term immunosuppression, in MMF-treated patients, CNIs can be replaced by SRL to avoid and/or halt progression of chronic nephropathy and to improve graft survival. However, some authors reported a high proportion of patients with oral ulcers and proteinuria after switching to SRL. In short, refining the use of MMF and SRL may provide a better risk/benefit ratio to pave the way towards non-nephrotoxic immunosuppression.

Mycophenolate mofetil and sirolimus combination in renal transplantation

Mycophenolate mofetil (MMF) and sirolimus (SRL) are potent non-nephrotoxic xenobiotic immunosuppressants. Their complementary properties may provide the rationale for their combination in induction and maintenance regimens. MMF, a reversible inhibitor of inosin monophosphate dehydrogenase (IMPDH) acts as an antiproliferative drug; and SRL, an mTOR (mammalian target of rapamycin) inhibitor, inhibits cell proliferation driven by growth factors. Early experiences with the use of the SRL, MMF and steroid combination yielded insufficient prophylaxis of acute rejection. However, the introduction of induction therapy with mono- or polyclonal antilymphocyte antibodies to the SRL-MMF and steroid combination brings an efficient acute rejection prophylaxis, while improving renal function and/or reducing of chronic allograft nephropathy (CAN). However, adverse events related to the use of this drug combination (mainly haematological and surgery-related) result in a high rate of discontinuations in some trials, which may hamper the potential benefits of this calcineurin-inhibitor (CNI)-free strategy. Also, currently under investigation is whether in long-term immunosuppression, in MMF-treated patients, CNIs can be replaced by SRL to avoid and/or halt progression of chronic nephropathy and to improve graft survival. However, some authors reported a high proportion of patients with oral ulcers and proteinuria after switching to SRL. In short, refining the use of MMF and SRL may provide a better risk/benefit ratio to pave the way towards non-nephrotoxic immunosuppression.

Subclinical rejection impairs glomerular adaptation after renal transplantation

After transplantation, glomerular volumes increases and large glomerular volume at 4 months is associated with better renal function. The aim is to characterize glomerular adaptation after the fourth month in two serial protocol biopsies and its relationship with subclinical rejection and chronic allograft nephropathy (CAN). Mean glomerular volume (Vg) was estimated according to the Weibel and Gomez method in a 4-month and 1-year serial protocol biopsies in 61 stable grafts. Glomerular enlargement (deltaVg) was calculated as the Vg difference between both biopsies. Banff schema was used to evaluate renal biopsies. Vg increased from 4.4+/-2.4 to 5.7+/-2.6 x 10(6) microm3 (P<0.001). Mean deltaVg was 1.0 x 10(6) microm3. Patients with deltaVg<1 were considered as patients with impaired glomerular enlargement (n=29). Impaired glomerular enlargement was associated with increased acute index score in the 4-month (1.83+/-1.56 vs 1.06+/-1.48; P<0.05) and 1-year protocol biopsies (1.52+/-1.59 vs 0.62+/-1.07; P<0.05). Impaired glomerular enlargement was also associated with increased progression of chronic lesions between the 4-month and 1-year biopsy in the glomerular (0.17+/-0.38 vs 0.55+/-0.63; P<0.01), tubular (0.38+/-0.56 vs 0.83+/-0.85; P<0.01), and interstitial compartment (0.41+/-0.57 vs 0.90+/-0.86; P<0.01). The proportion of sclerotic glomeruli between both biopsies increased in patients with impaired glomerular enlargement (1.5+/-3.9 to 5.3+/-10.1, P<0.05) while it did not modify in patients with glomerular enlargement (2.1+/-7.3 vs 2.6+/-4.5; P=NS). During the first year, glomeruli enlarge but this adaptation mechanism is impaired in patients with subclinical rejection. Moreover, impaired glomerular enlargement is associated with progression of CAN.

HGF gene therapy attenuates renal allograft scarring by preventing the profibrotic inflammatory-induced mechanisms

Inflammatory processes and tissue scarring are characteristic features of chronic allograft nephropathy. Hepatocyte growth factor (HGF) has beneficial effects on renal fibrosis and it also ameliorates renal interstitial inflammation as it has been recently described. Contrarily to protein administration, intramuscular gene electrotransfer allows sustained release of HGF. So, here we hypothesized that gene therapy with human HGF would diminish the characteristic scarring of chronic allograft nephropathy either by antagonizing tissue fibrosis mechanisms or by reducing inflammation. Lewis rats transplanted with cold preserved Fischer kidneys received vehicle (NoHGF) or intramuscular plasmid DNA encoding HGF plus electroporation either before transplantation (IniHGF, early post-transplant cytoprotection of tubular cells) or 8/10 weeks after transplantation (DelHGF, delayed prevention of chronic mechanisms). Serum creatinine and proteinuria were measured every 4 weeks for 24 weeks. Grafts at 12 or 24 weeks were evaluated for glomerulosclerosis, fibrosis inflammatory cells and mediators, cell regeneration and tubulo-interstitial damage. Nontreated animals developed renal insufficiency, progressive proteinuria and fibrosis among other characteristic histological features of chronic allograft nephropathy. Treatment with human HGF, especially when delayed until the onset of fibrogenic mechanisms, reduced renal failure and mortality, diminished tubule-interstitial damage, induced cell regeneration, decreased inflammation, NF-kappaB activation, and profibrotic markers at 12 weeks and prevented late interstitial fibrosis and glomerulosclerosis. The effectiveness of HGF-gene therapy in the prevention of renal allograft scarring is related with the halt of profibrotic inflammatory-induced mechanisms.

Subclinical rejection associated with chronic allograft nephropathy in protocol biopsies as a risk factor for late graft loss

Chronic allograft nephropathy (CAN) in protocol biopsies is associated with graft loss while the association between subclinical rejection (SCR) and outcome has yielded contradictory results. We analyze the predictive value of SCR and/or CAN in protocol biopsies on death-censored graft survival. Since 1988, a protocol biopsy was done during the first 6 months in stable grafts with serum creatinine <300 micromol/L and proteinuria <1 g/day. Biopsies were evaluated according to Banff criteria. Borderline changes and acute rejection were grouped as SCR. CAN was defined as presence of interstitial fibrosis and tubular atrophy. Mean follow-up was 91 +/- 46 months. Sufficient tissue was obtained in 435 transplants. Biopsies were classified as normal (n = 186), SCR (n = 74), CAN (n = 110) and SCR with CAN (n = 65). Presence of SCR with CAN was associated with old donors, percentage of panel reactive antibodies and presence of acute rejection before protocol biopsy. Cox regression analysis showed that SCR with CAN (relative risk [RR]: 1.86, 95% confidence interval [CI]: 1.11-3.12; p = 0.02) and hepatitis C virus (RR: 2.27, 95% CI: 1.38-3.75; p = 0.01) were independent predictors of graft survival. In protocol biopsies, the detrimental effect of interstitial fibrosis/tubular atrophy on long-term graft survival is modulated by SCR.

Long-term effect of hepatitis C virus chronic infection on patient and renal graft survival

BACKGROUND

Hepatitis C virus (HCV) infection increases morbimortality in renal transplantation. The immune response against the HVC is not predictable in a great proportion of patients developing into chronic liver disease, glomerulonephritis, or both.

PATIENTS

We analyzed the impact of posttransplant chronic hepatitis development on patient and graft survival in 200 HCV-positive/HBsAg-negative renal allograft recipients transplanted between 1981 and 2003.

RESULTS

Ninety-eight patients developed chronic ALT elevation (ALT+), while 102 did not (ALT-). There was no difference in acute rejection episodes (ARE), acute tubular necrosis, donor and recipient age, gender, HLA mismatches, and number of previous renal transplants. Development of ALT+ was associated with a worse patient survival (90% vs 65% at 15 years of follow-up, P = .007; RR = 3.8, CI = 1.4-10.1), an effect that was independent of other variables as time on dialysis and age. The main causes of death among ALT+ were chronic liver disease (52%), cardiovascular (26%), and infection (13%), whereas in ALT- they were cardiovascular (33%), cancer (33%), and chronic liver disease (16%). Conversely, graft survival (censoring for patient death with a functioning graft) was higher among ALT+ (50% vs 35% at 15 years of follow-up, P = .04; RR = 1.5, CI = 1.19-2.22). Causes of graft loss in ALT- patients were chronic allograft nephropathy (CAN, 53%), glomerulonephritis (GN, 18%), acute rejection episode (AR, 22%), and death (5%), whereas among ALT+ they were CAN (36%), GN (31%), ARE (10%), and death (21%; P = .01). By multivariate analysis, ALT- (RR = 1.6, CI = 1.07-2.55, P = .02) and de novo GN (RR = 2, CI = 1.29-3.09, P = .002) were associated with worse renal allograft survival.

CONCLUSION

Our results suggested that a better immune response against the HCV lead to greater patient survival but poorer graft survival.

Calcineurin-inhibitor-sparing immunosuppressive protocols

Calcineurin inhibitors (CNI) have played an important role in improving graft survival. However, the balance between preventing immunologic allograft losses and the management of CNI-related nephrotoxicity is still an issue in renal transplantation. There are three major CNI-sparing strategies. CNI MINIMIZATION: The advent of mycophenolate mofetil (MMF) allows cyclosporine (CsA) reduction to ameliorate renal function in patients with chronic renal allograft dysfunction, without increasing acute rejection rates. In combination with mTOR inhibitors, very low CNI levels may be sufficient to prevent acute rejection. However, in this association, CNI nephrotoxicity is magnified by pharmacokinetic interaction. CNI WITHDRAWAL: CNI withdrawal has been attempted in regimens containing MMF or sirolimus (SRL). Introduction of MMF in patients with chronic allograft nephropathy (CAN) followed by CNI withdrawal resulted in stabilization or improvement of renal function and hypertension profile, although there is some risk of acute rejection. In regimes based on SRL, CNI withdrawal is a safety strategy, achieving a sustained improvement of renal function, histology, and graft survival. There is not consensus at all whether MMF should be added or not in patients converted from CNI to mTOR inhibitor. CNI AVOIDANCE: Polyclonal-based regimens with MMF and steroids have shown acceptable acute rejection rates, but high rates of cytomegalovirus (CMV) and opportunistic infections. Conversely, anti-IL-2R in combination with MMF and steroids resulted in 50% incidence of acute rejection, thus suggesting that CNI avoidance is not feasible in a regimen based on MMF. Alternatively, a protocol based on anti-IL-2R induction therapy combined with SRL, MMF, and prednisone has shown an efficient prevention of acute rejection, higher creatinine clearance and lower rate of CAN in comparison with a group treated with CNI. New strategies using costimulation blockade may help in the development of safe CNI-free regimens. In summary, in renal transplantation the new immunosuppressive medications have made feasible old aspirations such as minimization, withdrawal, or even avoidance of CNI.

Glomerular size in early protocol biopsies is associated with graft outcome

Long-term consequences of glomerular enlargement after transplantation are not well understood. The aim is to evaluate the relationship between glomerular volume (Vg) estimated in protocol biopsies, graft function and graft survival. Vg and Banff chronic damage score were evaluated in protocol biopsies at 4 months. Creatinine clearance (CrCl) was estimated by the Cockroft-Gault formula. Vg estimated in 144 patients was 4.8 +/- 2.0 x 10(6)mu(3). It was associated with donor age (r = 0.23, p < 0.01), recipient body mass index (r = 0.17, p = 0.04), delayed graft function (Vg = 5.9 +/- 2.3 vs. 4.6 +/- 1.9 x 10(6)mu(3), p < 0.01) and CrCl (r = 0.17, p = 0.04). The best cutoff of Vg, Banff chronic damage score and CrCl was determined by Cox regression analysis, being 5.0 x 10(6)mu(3) for Vg (relative risk (RR): 2.4, 95% confidence interval (CI): 1.03-5.6), >2 for chronic damage score (RR: 3.4, 95% CI: 1.03-8.9) and 60 mL/min for CrCl (RR: 3.5, 95% CI: 1.04-11.9). These variables were independent predictors of death-censored graft survival. According to Vg and CrCl, four groups of patients were defined. Patients with small glomeruli and high CrCl had a 95% graft survival while patients with large glomeruli and low CrCl had a 45% graft survival at 15 years (p < 0.01). Large glomerular volume, high Banff chronic score and poor early renal function in stable grafts are independently associated with death-censored graft survival.

Role of Cold Ischemia in Acute Rejection: Characterization of a Humoral-Like Acute Rejection in Experimental Renal Transplantation

The aim of the study was to characterize the role of cold ischemia in the process of acute rejection using an experimental renal transplant model. Syngeneic renal transplants were performed between Wistar Agouti rats and allogeneic grafts using Wistar-Agouti rats as recipients of Brown-Norway kidneys. For cold ischemia (CI), kidneys were preserved in Euro-Collins (4 degrees C/ 2.5 hours). Rats were bilaterally nephrectomized at the moment of renal transplant and did not receive any immunosuppressant. The groups were NoAR (n = 6): immediate syngeneic transplant; CI-NoAR (n = 6): syngeneic transplant with CI; AR (n = 13): immediate allogeneic graft; CI-AR (n = 6): allogeneic graft with CI. Allogeneic rats were followed for the survival study. Syngeneic rats, with mean survival time beyond 6 months, were sacrificed on the day 7 to compare grafts with those in the allogeneic groups. H&E- and PAS-stained grafts were evaluated using the Banff criteria. Tissue INF-gamma and TNF-alpha were quantified by RT-real time-PCR on the kidney grafts. Renal insufficiency did not appear in the NoAR group, but it did from the posttransplant day 5 in both acute rejection groups. While NoAR kidneys showed well-conserved renal architecture, then AR group displayed variable degrees of tubular necrosis with scarce cellular infiltration, interstitial hemorrhage, vascular damage with fibrinoid necrosis, perivascular edema, and nuclear disruption. Cold ischemia in rejecting animals increased the mortality rate due to renal insufficiency and accelerated acute rejection. Independently of CI, the proinflammatory cytokines TNF-alpha and INF-gamma were increased in both rejection groups. In conclusion, addition of CI overactivates the acute rejection process via a humoral component.

Arterial Elasticity Measurement in Renal Transplant Patients Under Anticalcineurin Immunosuppression

INTRODUCTION

Calcineurin inhibitors may be associated with decreased arterial elasticity and increased vascular risk. We measured pulse wave velocity (PWV) in large or small arteries as an index of elasticity. The aim of our study was to determine aortic and radial arterial elasticity in 30 stable kidney transplant patients treated with calcineurin inhibitor immunosuppression.

PATIENTS AND METHODS

In stable kidney transplant patients we determined the usual biochemical parameters as well as lipid profiles, 24-hour blood pressure (BP) monitoring (CBPM) using a chronobiological program (Garapa), and PWV with a HDI-PWV CR-2000 monitor.

RESULTS

Sixteen patients received cyclosporine (CsA, G-1) and 14 tacrolimus (G-2) immunosuppression. There were no baseline differences regarding age (G-1: 56 +/- 12 years, G-2: 56 +/- 14 years), renal transplant follow-up (G-1: 7 +/- 3 years, G-2: 7.5 +/- 3 years), Systolic BP, pulse pressure or plasma creatinine (G-1: 163 +/- 35 umol/L, G-2: 173 +/- 26 umol/L). Patients in the G-1 showed higher diastolic BP (79 +/- 11 vs 74 +/- 8 mm Hg), greater proteinuria (1.26 +/- 0.4 vs 0.6 +/- 0.2 g/d, P < .05), total cholesterol (5.51 +/- 1.2 mmol/L) and low-density lipoprotein (3.08 +/- 0.3 vs 2.99 +/- 0.3 mmol/L, P = NS). Aortic arterial elasticity was decreased in G-1 patients (10.4 +/- 6 vs 14.3 +/- 2 mL/mm Hg x10, P < .05) as well as that in the radial artery (G-1: 5.52 +/- 1 vs 5.57 +/- 1.2 mL/mm Hg x100, P = NS). Almost 100% of the patients presented normal diurnal BP with high nocturnal BP in a nondipper pattern in both groups.

CONCLUSION

Calcineurin immunosuppression may contribute to arterial stiffness in kidney transplant patients. No differences between CsA or tacrolimus were observed in our study. CBPM and PWV are useful tools to evaluate subclinical atherosclerosis in renal transplant patients.

Therapy With Plasmapheresis and Intravenous Immunoglobulin for Acute Humoral Rejection in Kidney Transplantation

BACKGROUND

Acute humoral rejection (AHR) is characterized by acute graft dysfunction associated with de novo production of donor-specific alloantibodies (DSA) and C4d deposition in peritubular capillaries of the renal allograft. It has been reported the combination of plasmapheresis (PP) and intravenous gamma globulin (IVIG) as effective rescue therapy for established AHR.

METHODS

Between 1999 and 2004, seven kidney allografts recipients suffered from AHR diagnosed by severe rejection and C4d staining in peritubular capillaries. All patients had a negative cross-match before renal transplantation.

RESULTS

All patients were treated with daily sessions of PP and in four cases IVIG was added after the last PP session. Tacrolimus and mycophenolate mofetil were employed as maintenance immunosuppressive regimen. In one case, rituximab was added to PP and IVIG owing to refractory humoral rejection. At 1 year, patient survival was 100%, allograft survival was 70%, and the mean serum creatinine was 201 micromol/L.

CONCLUSIONS

AHR is a severe form of rejection associated with a poor prognosis, but its early diagnosis and treatment with PP and IVIG allows reversal of AHR reaching a 70% graft survival at 1 year.

Direct electrotransfer of hHGF gene into kidney ameliorates ischemic acute renal failure

In the early phase of kidney transplantation, the transplanted kidney is exposed to insults like ischemia/reperfusion, which is a leading cause of acute renal failure (ARF). ARF in the context of renal transplantation predisposes the graft to developing chronic damage and to long-term graft loss. Hepatocyte growth factor (HGF) has been suggested to support the intrinsic ability of the kidney to regenerate in response to injury by its morphogenic, mitogenic, motogenic and antiapoptotic activities. In the present paper, we examine whether human HGF (hHGF) gene electrotransfer helps in the recovery from ARF in a model of rat renal warm ischemia. We also assess the advantages of this form of gene therapy by direct electroporation of the kidney, given that transplantation offers the possibility of manipulating the organ in vivo. We have compared the therapeutic efficiency of two electroporation methodologies in a rat ARF model. Although they both targeted the same organ, the two methods were applied to different parts of the animal: muscle and kidney. Kidney direct electrotransfer was shown to be more efficient not only in pharmacokinetic but also in therapeutic terms, so it may become a clinically practical alternative in renal transplantation.

Beneficial effect of concomitant induction with antilymphoblast globulin, cyclosporine, and steroids on long-term renal allograft outcome

BACKGROUND

The addition of induction therapy with antilymphocytic antibodies to cyclosporine (CsA) based immunosuppression, has reduced acute rejection incidence and improved short-term survivals, but has not had well-established effects on long-term renal transplant survival.

PATIENTS

We analyzed the long-term allograft outcome of patients included in a prospective randomized clinical study conducted in our center 15 years ago by comparing two strategies: (A) horse antilymphoblast globulin (ALG) given at 10 mg/kg on alternate days to a maximum of 6 doses with low-dose CsA started at 8 mg/kg per day and prednisone at 0.25 mg/kg per day, versus (B) CsA started at 15 mg/kg per day and prednisone at 0.5 mg/kg per day. Diabetic and highly sensitized patients (PRA > 70%) were excluded from the study.

RESULTS

The characteristics of the 50 patients enrolled in each group were not different. Although patient survival was not different (88% in group A vs 77% in group B), recipients treated with ALG showed a lower incidence of acute rejection episodes (20% vs 44%, P = .01) and better death-censored renal allograft survival (57% vs 41%, P = .03). Among rejection-free patients, graft survival was 15% higher in group A (60% vs 45%, P = .12). Multivariate Cox regression analysis showed that an acute rejection episode (relative risk [RR]: 2.44, 95% confidence interval [CI] 1.36-4.39; P = .0029) rather than ALG immunosuppression (RR 0.74, 95% CI 0.41-1.33; P = NS) was an independent predictor of death-censored graft survival.

CONCLUSIONS

In summary, we confirmed that concomitant induction therapy with ALG, CsA, and steroids improves long-term renal allograft survival.

Cyclosporine nephrotoxicity

The polypeptide immunosuppressant cyclosporine is a prodrug that binds an intracellular immunophilin. The complex cyclosporine-cyclophilin binds and inhibits the phosphatase activity of calcineurin interfering with the dephosphorilation of members of the nuclear factor of activated T cells, which is involved in the regulation of genes encoding many cytokines. However, calcineurin is not exclusive from T cells; it is also present in many organs, such as the kidney, and their inhibition accounts for both the immunosuppressive and the nephrotoxic effects of cyclosporine. In renal transplantation, it was shown that graft survival improved progressively between 1998 to 1996, mainly due to reduction of acute rejection episodes. There is no doubt that cyclosporine contributed to that success. After 20 years, cyclosporine targets for maintenance immunosuppression have not been defined and the magnitude of chronic cyclosporine nephrotoxicity in renal allografts is not known, in part by the limitations of histologic classification of chronic allograft nephropathy. In the future, the new technology based on DNA microarrays can be a valuable tool to separate chronic drug toxicity from other causes of graft deterioration. On the other hand, in the cyclosporine era, chronic renal failure has emerged as a frequent adverse event after transplantation of nonrenal organs and it is associated with increased risk of death. Although there is not yet enough evidence to support a generalization of calcineurin-free immunosuppression, we should open our minds to the upcoming new concepts on immunosuppression.

Optimizing cadaveric organ procurement: the catalan and Spanish experience

The need to face the increasing gap between the supply and the demand of transplants has led to the development of a permanent network of trained medical staff responsible for the organ donation and removal process in all centers accredited for that process. In Spain, this activity received a specific budget, like any other medical activity in hospitals, and the responsible staff became accountable for performance. This system dramatically increased the number of potential donors referred, not only young donors with trauma, but also elderly donors dying from stroke. The effect was that the donation rate increased by more than 100% in 10 years (from 14 to 34 donors per million population). Consequently, so did all the transplant figures. In some areas, such as Catalonia, it has been demonstrated that sustained kidney transplant activity of over 60 procedures per million population can maintain or slightly decrease the waiting list, despite increasing incidence and prevalence of end-stage renal failure. Quality monitoring of the donation and retrieval process shows that there are still opportunities for improvement if all potential donors are referred and all technical problems are overcome. Living donation and nonheart beating organ retrieval should also be promoted.

Doxazosin GITS trough to peak ratio and 24-hour blood pressure monitoring in the management of hypertension in renal transplant patients

We have studied 20 patients, 10 male, 10 female, mean age 52.5+/-10.9 years, who received a cadaver kidney transplant between June 1996 and January 1999. The patients presented with mild or moderate high BP and were treated on a maintained immunosuppression with an anti-calcineurin agent and steroids, associated or not to mycophenolate-mofetil. At baseline, a 24-hour ambulatory BP monitoring was performed. General biochemical parameters were determined and doxazosin GITS (Gastro-Intestinal Therapeutic System) in a single dose of 4 mg/d was started. Doxazosin GITS was titrated four weeks after up to 8 mg/d if the BP was greater than 140/90 mm Hg. At week 12, biochemical analysis were repeated as well as the 24-hour BP monitoring and the T/P ratio was calculated.

RESULTS

The patients were divided in responders, T/P index >50%, n=10 or not-responders, T/P index <50%, n=10 patients). No differences in systolic BP (SBP), diastolic BP(DBP), plasma creatinine or proteinuria were seen at base-line. DBP was lower in responders than in non-responders (P=ns). Doxazosin doses were 5.5+/-3 mg/d vs 5.8+/-3 and T/P ratio 0.70+/-0.13 vs 0.17+/-0.14, (P=.001). There were no variations in pl. t. cholesterol, triglycerides, glucose or uric acid.

CONCLUSIONS

Treatment was safe and efficient, not increasing metabolic adverse effects. Doxazosin GITS is a safe agent which can reduce cardiovascular risk. In our patients, the good T/P ratio has been associated with a best diastolic BP control. This good profile should be taken into account for 24-hour BP control in hypertensive renal transplant patients.

[Effect of cyclosporin and tacrolimus on lipoprotein oxidation after renal transplantation]

BACKGROUND

Cyclosporin A is a lipogenic immunosuppressor that can induce posttransplant hyperlipidaemia. Oxidation of low-density lipoprotein (LDL) has been recognized as a major atherogenic factor. Tacrolimus seems to be less lipogenic with an apparently better cardiovascular profile than CsA.

METHODS

We have studied the lipidic profile and the oxidation of HDL and LDL in 20 renal transplant patients, 12 male and 8 female, mean age 45 +/- 10 year, who where switched from CsA to tacrolimus due to CsA adverse effects. LDL were determined by ultracentrifugation. Oxidation study before and 6 months after conversion to tacrolimus was performed by adding CuSO4.

RESULTS

After conversion, systolic blood pressure (BP) decreased from 154 +/- 21 to 133 +/- 21 mm Hg (p = 0.008), diastolic BP from 97 +/- 13 to 77 +/- 15 mm Hg (p = 0.016), total cholesterol from 6.08 +/- 0.9 to 5.68 +/- 1.1 mmol/l (p = 0.02), LDL-chol from 3.29 +/- 1.01 to 2.96 +/- 0.3 mmol/l (p = 0.04) and apo-B lipoprotein from 1.42 +/- 0.28 to 1.15 +/- 0.34 mg/dl (p = 0.003). The oxidation of LDL improved after conversion: the initial dienic compounds decreased from 95 +/- 20 to 63 +/- 12 umol/g and the final DC from 207 +/- 56 to 107 +/- 35 umol/g. Lag-phase increased from 33 +/- 21 to 45 +/- 17 min (p < 0.05).

CONCLUSION

Tacrolimus has improved hyperlipidaemia in our cyclosporin previously treated patients and increased the resistance to oxidation of high and low-density lipoproteins.

Hepatitis C virus infection and de novo glomerular lesions in renal allografts

In the present study we examine whether hepatitis C virus (HCV) infection status influences glomerular pathologic findings in renal allografts and its effect on graft outcome. Renal allograft biopsies performed between January 1991 and June 1999 were considered. Exclusion criteria were insufficient sample, unknown HCV serological status at time of biopsy and final diagnosis of acute rejection. Light microscopy and immunofluorescence studies were performed on all biopsies. According to a predefined protocol, electron microscopy was carried out. Of 138 eligible renal allograft biopsies, 42 fulfilled at least one exclusion criterion. Of 96 biopsies selected for the study, 44 (45.8%) were from HCV-positive and 52 from HCV-negative recipients. Renal biopsy was performed 74 +/- 55 and 60 +/- 39 months after transplantation in HCV-positive and HCV-negative groups, respectively (p = 0.12). Of 44 HCV-positive biopsies, 20 (45.4%) showed membranoproliferative glomerulonephritis (MPGN) (16 type I and 4 type III). Conversely, in HCV-negative biopsies there were only three cases of MPGN (2 type I and 1 type III). De novo membranous GN (MGN) was diagnosed in 8/44 (18.2%) HCV-positive and in 4/52 (7.7%) HCV-negative cases. The prevalence of chronic transplant glomerulopathy was similar in HCV-positive and HCV-negative groups (11.4% and 11.5%, respectively). The prognosis of de novo GN (either MPGN or MGN) was worse in HCV-positive than in HCV-negative recipients (relative risk 4.89; 95% confidence interval, 1.15-20.69; p = 0.03). By multivariate analysis, HCV-positive serology infection was the only independent predictor of graft loss (relative risk 2.64; 95% confidence interval, 1.35-5.17; p = 0.005). In diagnostic renal allograft biopsies the presence of de novo immune-mediated glomerulonephritis, especially type I MPGN, is strongly associated with HCV infection and results in accelerated loss of the graft.