Institutional Experience With New Antidiabetic Drugs in Kidney Transplant

BACKGROUND

The recent introduction of new antidiabetic drugs, analogs of glucagon-like peptide-1 (GLP-1) and sodium-glucose cotransporter 2 inhibitors, has shown excellent results in the management of patients with diabetes with chronic kidney disease. However, documented results of these medications in the population that has undergone kidney transplant are sparse. We report our institutional experience with them, including occurrence of side effects and possible interactions with immunosuppressive medications.

METHODS

A retrospective analysis of 15 patients (10 with diabetes and 5 without diabetes but with obesity) managed with these medications was carried out in the kidney transplant unit of Hospital Doctor Peset during the year 2019. Data acquired at baseline and 3, 6, and 12 months were analyzed.

RESULTS

The median hemoglobin A1c at baseline was 6.7 (interquartile range [IQR] = 5.8-8.2) and at 12 months it was 6 (IQR = 5.3-8.1, P = .96). The mean weight difference at 12 months was a loss of 7.2 ± 6 kg; median body mass index at baseline was 31.2 kg/m² (IQR = 29.7-35.5) and 29.5 kg/m² (IQR = 27.6-31.6, P = .01) at 12 months. In addition to weight loss, a reduction in insulin and oral antidiabetic drug requirements was observed. No significant changes were detected in serum creatinine or proteinuria values and the immunosuppressant levels remained stable. No acute rejection episodes were observed.

CONCLUSION

Based on our experience, the new antidiabetic drugs are safe, with no significant changes in renal function or immunosuppressant levels or clinically important adverse effects.

Disorders in bone-mineral parameters and the risk of death in persons with chronic kidney disease stages 4 and 5: the PECERA study

BACKGROUND

Abnormalities of bone mineral parameters are associated with increased mortality in patients on dialysis, but their effects and the optimal range of these biomarkers are less well characterized in non-dialysis chronic kidney disease (CKD).

METHODS

PECERA (Collaborative Study Project in Patients with Advanced CKD) is a 3-year, prospective multicenter, open-cohort study of 966 adult patients with non-dialyzed CKD stages 4-5 enrolled from 12 centers in Spain. Associations between levels of serum calcium (Ca) (corrected for albumin), phosphate (P), and intact parathyroid hormone (iPTH) with all-cause mortality (primary outcome) and cardiovascular mortality (secondary outcome) were examined using time-dependent Cox proportional hazards models and penalized splines analysis adjusted by demographics and comorbidities, treatments and biochemical values collected every 6 months for 3 years.

RESULTS

After a median follow-up of 29 months (IQR: 13-36 months) there were 181 deaths (19%). The association of calcium with all-cause mortality was J-shaped, with an increased risk for all-cause mortality at levels > 10.5 mg/dL. For phosphate and iPTH levels, the association was U-shaped. The serum values associated with the minimum risk of mortality were 3.8 mg/dL for phosphate and 70 pg/mL for iPTH, being the lowest risk ranges between 2.8 and 5.0 mg/dL, and between 38 and 112 pg/mL for phosphate and iPTH, respectively.

CONCLUSIONS

Our study provides evidence on the non-linear association of serum calcium, phosphate and iPTH levels with mortality in stage 4 and 5 CKD patients, and suggests potential survival benefits for controlling bone mineral parameters in this population, as previously reported for dialysis patients.

P0877ASSOCIATIONS OF DISORDERS IN BONE MINERAL PARAMETERS WITH MORTALITY IN STAGE 4 AND 5 CKD: INSIGHTS FROM THE PECERA STUDY

Background and Aims

Abnormalities of bone mineral parameters are associated with increased mortality in patients on dialysis, but their effects and the optimal range of these biomarkers are less well characterized in non-dialysis chronic kidney disease (CKD).

Method

PECERA (Collaborative Study Project in Patients with Advanced Chronic Kidney Disease) is a 3-year, multicentre, open-cohort, prospective study carried out in 995 adult patients with CKD stages 4-5 not on dialysis enrolled in 2007-09 from 12 centres in Spain. Associations between levels of serum calcium (corrected for serum albumin), phosphate, and intact parathyroid hormone (iPTH) and all-cause mortality were examined using time-dependent Cox proportional hazards models and penalized splines analysis adjusted by demographics and comorbidities, treatments and biochemical collected at baseline and every 6 months for 3 years.

Results

After a median follow-up of 30 months (IQR:14-37 months) there were 180 deaths (18%). The association of calcium and phosphate with all-cause mortality was U-shaped (Figure). The serum values associated with the minimum risk of mortality were 9.35 mg/dL for calcium and 3.56 mg/dL for phosphate, being the lowest risk ranges between 7.4 to 10.7 mg/dL and between 2.3 to 4.6 mg/dL for calcium and phosphate, respectively. For iPTH levels, the association was J-shaped, with an increased risk for all-cause mortality at levels > 110 pg/mL.

Conclusion

As previously reported in dialysis patients, PECERA provided evidence on the association of serum calcium, phosphate and iPTH levels with all-cause mortality in stage 4 and 5 CKD patients, suggesting potential survival benefits of controlling bone mineral parameters in this population. Whereas the ranges of calcium and phosphate associated with the lowest mortality in the study were consistent with the current K-DIGO guidelines, our results suggested that the threshold for considering anti-parathyroid treatment might be lower than is currently recommended.

P1082COMPARISON OF THE REMOVAL OF PROTEIN-BOUND TOXINS AND LARGE MIDDLE MOLECULES WITH HIGH-FLUX PMMA AND MEDIUM CUT-OFF DIALYZERS

Background and Aims

Dialytic clearance of protein-bound toxins and large middle molecules is poor by diffusive treatment and limited by high-flux hemodialysis (HD) and on-line hemodiafiltration (OL-HDF), and only a few studies have examined how to improve their removal by other extracorporeal strategies. Since 2017, there is a new generation of polymethyl methacrylate (PMMA) membranes that suppress platelet adhesion on the membrane surface improving hemocompatibility and permeability, while also maintaining adsorption properties related to conventional PMMA membranes. Expanded HD (HDx) with medium cut-off (MCO) membranes has also recently been incorporated into clinical practice and may improve the removal of uremic toxins in HD treatments. The aim of this pilot study was to compare the efficacy of a new high-flux PMMA dialyzer (Filtryzer® NF-2.1H) in a post-dilution OL-HDF session with a new MCO membrane (Theranova® 400) in a HDx session.

Method

In an open, cross-over, single-center, controlled, prospective clinical study, 40 adult stable HD patients were assigned to be treated by post-dilution OL-HDF with the NF-2.1H dialyzer or by HDx with the Theranova 400 dialyzer. All other dialysis parameters, including blood and dialysate flow rates, length of dialysis session, and ultrafiltration rate remained unchanged during both sessions. P-cresyl sulfate (PCS), indoxyl sulfate (IS), and kappa (κ) and lambda( λ) free light chains (FLC) reduction rates were intraindividually compared for the two dialyzer types (primary outcomes). Secondary outcomes included the kt and the reduction ratio of blood urea nitrogen, phosphate and β2 -microglobulin (β 2-m).

Results

The reduction ratio of protein-bound toxins ranges from 60% to 67%, with no differences between membranes (Figure). PMMA membrane achieved greater FLC reduction ratios than MCO membrane, reaching significance for λFLC (56.6% vs. 77.4%; p < 0.001). Conversely, β2M reduction ratio was slightly but significantly higher with MCO membrane (68.5 vs. 72.1%; p = 0.002). Small molecules removal including urea and phosphate were similar in both groups, achieving an optimal Kt with no differences between groups (61.3±9.2 Vs. 59.7±9.3; p=0.16). Albumin reduction ratio tended to be higher with PMMA membrane without reaching significance (10.1±5.9% Vs. 7.8±12.3%; p=0.17). The mean convective volume achieved with PMMA was 23.5±4.4 L.

Conclusion

This study suggested that new high-flux PMMA dialyzer in post-dilution OL-HDF mode might achieve better FLC reduction ratios than MCO dyalizer in HDx mode, whereas both techniques may equally remove protein-bound toxins. OL-HDF with new PMMA membranes could be a good dialysis strategy for adding convective transport to the well-known mechanisms of diffusion and absorption previously described with conventional PMMA membranes, enabling an adequate substitution volume.

P1055REMARKABLE REMOVALS OF BETA-2-MICROGLOBULIN AND PHOSPHATE WITH SHORT-DAILY HOME HEMODIALYSIS USING LOW DIALYSATE FLOW RATE

Background and Aims

Short-daily hemodialysis (HD) with low-dialysate volume is an appealing portable dialysis approach for home use. Although this type of HD has proved being effective for the volume control and the clearance of low molecular-weight uremic toxins, limited data are available on the impact on the removal rates of other uremic toxins like β2-microglobulin (β2M) or phosphate (P), whose clearance is limited by sequestration into compartments, poor diffusion, high time-dependency, or protein binding. We evaluated the impact of short-daily HD with slow dialysate flow rate on the removal of solutes of different molecular weights and distribution volumes.

Method

Single-session and weekly balances of β2M, P, urea, and creatinine were prospectively assessed with total dialysate collection and serum measurements before and after 341 dialysis sessions (mean dialysate volume: 30963 ± 862 mL; mean length of dialysis session: 153 ± 8 min) in 31 stable patients (female; 9, 29 %; mean age: 55.6 ± 13.6 y; dry weight: 74.9 ± 13.3 kg) undergoing short-daily home HD with NxStage cycler, between July 2014 and October 2019. The mean blood flow rate was 365 ± 17 mL/min, whereas the mean dialysate flow rate was 194 ± 12 mL/min.

Results

Single-session β2M, P, urea, and creatinine removals were 0.138 ± 0.050 g, 0.610 ± 0.161 g, 18.89 ± 6.07 g and 1.07 ± 0.31 g, respectively, whereas the reduction rates (%) were 38.0 ± 13.0, 46.8 ± 8.6, 48.2 ± 7.0 and 46.6 ± 6.6, for β2M, P, urea and creatinine, respectively. The estimated weekly β2M, P, urea and creatinine removals in HDD patients dialyzing 5-6 days per week were comparable with 4-h in-center thrice-weekly on-line hemodiafiltration according to previous studies (Table 1).

Conclusion

Treating patients with short-daily HD with low-dialysate volume at a 5-6 days per week prescription may achieve an efficient weekly β2M and P removal.

The effect of high-volume online haemodiafiltration on nutritional status and body composition: the ProtEin Stores prEservaTion (PESET) study

Background

Compared with conventional haemodialysis (HD), online haemodiafiltration (OL-HDF) achieves a more efficient removal of uraemic toxins and reduces inflammation, which could favourably affect nutritional status. We evaluate the effect of OL-HDF on body composition and nutritional status in prevalent high-flux HD (HF-HD) patients.

Methods

In all, 33 adults with chronic kidney disease (CKD) Stage 5 undergoing maintenance HF-HD were assigned to post-dilution OL-HDF (n = 17) or to remain on HF-HD (n = 16, control group) for 12 months. The primary outcome was the change in lean tissue mass (LTM), intracellular water (ICW) and body cell mass (BCM) assessed by multifrequency bioimpedance spectroscopy (BIS) at baseline and 4, 8 and 12 months. The rate of change in these parameters was estimated with linear mixed-effects models.

Results

Compared with OL-HDF, patients assigned to HF-HD experienced a gradual reduction in LTM, ICW and BCM. These differences reached statistical significance at Month 12, with a relative difference of 7.31 kg [95% confidence interval (CI) 2.50-12.11; P = 0.003], 2.32 L (95% CI 0.63-4.01; P = 0.008) and 5.20 kg (95% CI 1.74-8.66; P = 0.004) for LTM, ICW and BCM, respectively. The normalized protein appearance increased in the OL-HDF group compared with the HF-HD group [0.26 g/kg/day (95% CI 0.05-0.47); P = 0.002], with a relative reduction in high-sensitive C-reactive protein [-13.31 mg/dL (95% CI -24.63 to -1.98); P = 0.02] at Month 12.

Conclusions

OL-HDF for 1 year compared with HF-HD preserved muscle mass, increased protein intake and reduced the inflammatory state related to uraemia and dialysis, supporting the hypothesis that high convection volume can benefit nutritional status and prevent protein-energy wasting in HD patients.

Randomized Controlled Trial Assessing the Impact of Tacrolimus Versus Cyclosporine on the Incidence of Posttransplant Diabetes Mellitus

INTRODUCTION

Despite the high incidence of posttransplant diabetes mellitus (PTDM) among high-risk recipients, no studies have investigated its prevention by immunosuppression optimization.

METHODS

We conducted an open-label, multicenter, randomized trial testing whether a tacrolimus-based immunosuppression and rapid steroid withdrawal (SW) within 1 week (Tac-SW) or cyclosporine A (CsA) with steroid minimization (SM) (CsA-SM), decreased the incidence of PTDM compared with tacrolimus with SM (Tac-SM). All arms received basiliximab and mycophenolate mofetil. High risk was defined by age >60 or >45 years plus metabolic criteria based on body mass index, triglycerides, and high-density lipoprotein-cholesterol levels. The primary endpoint was the incidence of PTDM after 12 months.

RESULTS

The study comprised 128 de novo renal transplant recipients without pretransplant diabetes (Tac-SW: 44, Tac-SM: 42, CsA-SM: 42). The 1-year incidence of PTDM in each arm was 37.8% for Tac-SW, 25.7% for Tac-SM, and 9.7% for CsA-SM (relative risk [RR] Tac-SW vs. CsA-SM 3.9 [1.2-12.4; P = 0.01]; RR Tac-SM vs. CsA-SM 2.7 [0.8-8.9; P = 0.1]). Antidiabetic therapy was required less commonly in the CsA-SM arm (P = 0.06); however, acute rejection rate was higher in CsA-SM arm (Tac-SW 11.4%, Tac-SM 4.8%, and CsA-SM 21.4% of patients; cumulative incidence P = 0.04). Graft and patient survival, and graft function were similar among arms.

CONCLUSION

In high-risk patients, tacrolimus-based immunosuppression with SM provides the best balance between PTDM and acute rejection incidence.

Nephroprotection by Hypoglycemic Agents: Do We Have Supporting Data?

Current therapy directed at delaying the progression of diabetic nephropathy includes intensive glycemic and optimal blood pressure control, renin angiotensin-aldosterone system blockade and multifactorial intervention. However, the renal protection provided by these therapeutic modalities is incomplete. There is a scarcity of studies analysing the nephroprotective effect of antihyperglycaemic drugs beyond their glucose lowering effect and improved glycaemic control on the prevention and progression of diabetic nephropathy. This article analyzes the exisiting data about older and newer drugs as well as the mechanisms associated with hypoglycemic drugs, apart from their well known blood glucose lowering effect, in the prevention and progression of diabetic nephropathy. Most of them have been tested in humans, but with varying degrees of success. Although experimental data about most of antihyperglycemic drugs has shown a beneficial effect in kidney parameters, there is a lack of clinical trials that clearly prove these beneficial effects. The key question, however, is whether antihyperglycemic drugs are able to improve renal end-points beyond their antihyperglycemic effect. Existing experimental data are post hoc studies from clinical trials, and supportive of the potential renal-protective role of some of them, especially in the cases of dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors. Dedicated and adequately powered renal trials with renal outcomes are neccessary to assess the nephrotection of antihyperglycaemic drugs beyond the control of hyperglycaemia.

Vascular calcification in patients with nondialysis CKD over 3 years

BACKGROUND AND OBJECTIVES

Vascular calcification (VC) is common in CKD, but little is known about its prognostic effect on patients with nondialysis CKD. The prevalence of VC and its ability to predict death, time to hospitalization, and renal progression were assessed.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Study of Mineral and Bone Disorders in CKD in Spain is a prospective, observational, 3-year follow-up study of 742 patients with nondialysis CKD stages 3-5 from 39 centers in Spain from April to May 2009. VC was assessed using Adragao (AS; x-ray pelvis and hands) and Kauppila (KS; x-ray lateral lumbar spine) scores from 572 and 568 patients, respectively. The primary end point was death. Secondary outcomes were hospital admissions and appearance of a combined renal end point (beginning of dialysis or drop >30% in eGFR). Factors related to VC were assessed by logistic regression analysis. Survival analysis was assessed by Cox proportional models.

RESULTS

VC was present in 79% of patients and prominent in 47% (AS≥3 or KS>6). Age (odds ratio [OR], 1.05; 95% confidence interval [95% CI], 1.02 to 1.07; P<0.001), phosphorous (OR, 1.68; 95% CI, 1.28 to 2.20; P<0.001), and diabetes (OR, 2.11; 95% CI, 1.32 to 3.35; P=0.002) were independently related to AS≥3. After a median follow-up of 35 months (interquartile range=17-36), there were 70 deaths (10%). After multivariate adjustment for age, smoking, diabetes, comorbidity, renal function, and level of phosphorous, AS≥3 but not KS>6 was independently associated with all-cause (hazard ratio [HR], 2.07; 95% CI, 1.07 to 4.01; P=0.03) and cardiovascular (HR, 3.46; 95% CI, 1.27 to 9.45; P=0.02) mortality as well as a shorter hospitalization event-free period (HR, 1.14; 95% CI, 1.06 to 1.22; P<0.001). VC did not predict renal progression.

CONCLUSIONS

VC is highly prevalent in patients with CKD. VC assessment using AS independently predicts death and time to hospitalization. Therefore, it could be a useful index to identify patients with CKD at high risk of death and morbidity as previously reported in patients on dialysis.

Effects of immunosuppressive drugs on the cognitive functioning of renal transplant recipients: a pilot study

Some renal transplant patients show cognitive, emotional, and behavioral changes as part of possible neurotoxic effects associated with immunosuppressive medication, especially tacrolimus. This study evaluated effects of immunosuppressive drugs on some cognitive tasks. Patients treated with sirolimus and cyclosporine reported some of the noncognitive side effects related to immunosuppressive treatment. We observed attention and working memory impairment in patients treated with sirolimus or tacrolimus. Performance of cyclosporine-treated subjects was similar to that of healthy volunteer controls. Since the mood, anxiety, and sleep patterns measured were unaffected, it could be concluded that the cognitive deficit found was partly related to treatment.

Renal allografts from donors older than 70 years are useful for single transplantation

Kidney transplantation has been related in elderly recipients to a greater longevity compared with dialysis. Due to the scarcity of donors, transplantation of older patients depends on the acceptance of older donors. We compared the characteristics and evolution of transplants from donors >or=70 years (n = 53) with those from donors >55-<70 years (n = 201). Group D >or=70 included older recipients (65.37 +/- 4.9 vs 55.92 +/- 9.66 years; P = .000) and more women (62.3% vs 45.3%; P = .02), with more peripheral arterial disease (10.9% vs 2.4%; P = .011). No differences in donor characteristics were observed. Induction treatment with thymoglobulin or basiliximab was more common in D >or=70 (81.1% vs 57.3%; P = .006), with no differences in other immunosuppressive drugs. The incidence of delayed graft function (DGF) was similar (P = .82), with a trend to a lower incidence of acute rejection episodes among D>or=70 (11.8% vs 22.5%; P = 0.09). Serum creatinine and proteinuria levels did not differ during follow-up (P > .05). Patients in D >or=70 displayed more episodes of urinary sepsis (19.1% vs 6.4%; P = .008), but no differences were observed in cytomegalovirus (CMV) infection (P = .629), neoplasia (P = .118), ischemic cardiopathy (P = .642), or hospital readmission due to infections (P = .567). Graft survivals at 5 years were 70% and 75% (P = .279) among groups D >or=70 and D>55-<70, respectively, and patient survivals at 5 years were 88% and 88% (P = .63), respectively. In conclusion, our study showed that selected kidneys from donors older than 70 years were followed with excellent graft and patient survivals, permitting older patients on renal replacement therapy to benefit from renal transplantation.

Histological findings of early graft biopsies in old donor renal transplant patients receiving induction therapy

Since recipients of transplants from elderly donors are exposed to an increased risk of delayed graft function (DGF) and acute rejection episodes, administration of induction treatment represents an alternative to preserve renal mass and improve graft survival. We compared the evolution and histological findings of early graft biopsies among 38 recipients treated with Thymoglobulim (33.6%) versus 75 (66.4%) with basiliximab. No differences were observes in the rate of DGF (P = .39). Forty kidneys were biopsed during the first 2 weeks after transplantation: 9 in the Thymoglobulin group (23.68%) and 31 in the basiliximab group (41.3%). Histological evaluation showed: acute tabular necrosis in 7 (78%) Thymoglobulin patients versus 14 (45%) basiliximab patients, with calcineurin nephrotoxicity in 2 (22%) and 1 (3.2%), respectively. An acute rejection episode was not diagnosed in the Thymoglobulin group, but 13 patients (17.3%) in the basiliximab group experienced this complication (P = .006). Banff classification showed: 6 grade IA (19.4%), 1 grade IB (3.2%), 3 grade IIA (9.7%), 1 grade IIB (3.2%), and 2 grade III (6.5%). Six of these patients required rescue treatment with Thymoglobulin. Serum creatinine and proteinuria levels between the 2 groups were not different (P > .05). There were no differences in cytomegalovirus (CMV) disease (P = .152), admission due to infection (P = .120), or neoplasia (P = .29). Graft and patient survivals at 3 years did not show a difference. The histological findings revealed that low doses of Thymoglobulin were much more effective to prevent renal inflammation and acute rejection episodes than basiliximab among renal transplant recipients, albiet without differences in survival at a mean of 3 years follow-up.

Treatment of renal transplant failure

INTRODUCTION

Among graft failures beyond months, we performed progressive reduction and complete withdrawal of immunosuppressive drugs and steroids over a period of 6 months.

PATIENTS AND METHODS

We analyzed the treatment and complications associated with all late allograft failures in 34 patients (8.19%) out of 415 patients transplanted from November 1996 to November 2006.

RESULTS

In 21 patients (61.8%), the progressive reduction of immunosuppressive treatment was effective and well tolerated; however, in 13 patients (38.2%) there was rejection of the allograft at 10.74 +/- 8.95 months (0.77-34.80) after the failure. With the reintroduction of these drugs, the rejection was controlled in seven patients, but in the other six we had to embolize the allograft, which had to be repeated in one case. Embolization was well tolerated, but in one case there was migration of one coil to the femoral artery. One patient treated with drug withdrawal experienced emphysematous pyelonephritis after repeated urinary infections, requiring a nephrectomy. Thirteen (38.2%) of the patients with late failures have been admitted for a second transplant; five of them showed HLA sensitization.

CONCLUSIONS

Conservative treatment with progressive withdrawal of immunosuppression was effective and well tolerated in two-thirds of the patients with late renal allograft failure, but one-third of the patients rejected the graft and needed allograft embolization. Infection of the graft and HLA sensitization can complicate the course of these patients.

Effect of Overweight on Kidney Transplantation Outcome

INTRODUCTION

Obesity is a prevalent problem in renal transplant recipients that is followed by reduced graft and patient survivals. Because the prevalence of overweight (OW) is increasing in the renal transplant population, we studied the influence of OW on graft and recipient evolution.

PATIENTS AND METHODS

We analyzed a series of 337 patients with renal allografts having a mean follow-up of 53.4 +/- 30.6 months. We excluded 39 patients obese at transplantation. We compared the evolution of 134 OW patients (45.5%), and 160 patients (54.4%) with a body mass index <25 (NW group).

RESULTS

OW patients were older (P = .000) with a higher prevalence of hypertension (P = .028), left ventricular hypertrophy (P = .014), and dyslipidemia (P = .001). They had received kidneys from older donors (P = .019). OW patients showed a higher incidence of acute tubular necrosis (ATN) (P = .006), without a higher incidence of acute rejection episodes (P = .756). Postransplant diabetes mellitus was more frequent (P = .000), and systolic blood pressure (P < .05), total cholesterol (P < .05), and tryglicerides were higher (P < .05) in the OW group. Serum creatinine at 6 months (P = .007) and proteinuria >0.5 g/24 hours, (P = .023) were higher among the OW group. Graft survival was not different between groups, but patient survival was lower in the OW group (P = .002). A logistic regression analysis showed that the recipient age (RR: 5.243) and the presence of OW (RR: 1.100) were independent prognostic factors for patient death.

CONCLUSIONS

OW was a common situation among renal transplant candidates. It was associated with worse cardiovascular and metabolic profiles. OW patients showed worse allograft function and lower patient survival. A major effort must be exerted to avoid excessive weight gain, particularly among those OW at transplantation.

Calcineurin Inhibitor Reduction Based on Maintenance Immunosuppression With Mycophenolate Mofetil in Renal Transplant Patients: POP Study

Since calcineurin inhibitors (CNI) have been introduced, they have become the cornerstone of immunosuppression for renal transplant patients, but their cardiovascular and neurological toxicities, and primarily their renal toxicity, have brought about an increased effort to find combinations of immunosuppressants that are either CNI-free or that use minimum doses of these drugs. The weight of immunosuppression therefore lies with drugs that have a better toxicity profile. The POP observational transverse study including 213 renal transplant patients was designed to study CNI minimization strategies. The mean time of transplant evolution to the time of reduction was 9.9 +/- 11.8 months. The acute rejection rate to the start of reduction was 9.4%. Almost all the patients were undergoing treatment with CNI + mycophenolate mofetil (MMF) + steroids in the immediate posttransplantation period. When reduction was chosen, all patients were undergoing treatment with MMF (mean dose at the start of reduction = 1490.7 +/- 478.0 mg/d). Among the cohort, 66.7% of patients were being treated with tacrolimus (mean C0 levels 13.3 +/- 6.6 ng/mL) and 33.3% with cyclosporine (mean C0 levels 192.2 +/- 94.0 ng/mL; mean C2 levels 1097.5 +/- 457.6). The main reasons for withdrawal were nephrotoxicity (55.9% of the cases), as well as prevention of adverse effects (21.6%). The mean target CNI dose reduction was 41.4% +/- 21.45% in the tacrolimus group and 28.6 +/- 10.0% in the cyclosporine group. In conclusion, CNI toxicity, primarily renal toxicity, makes reduction of these drugs based on the use of full MMF doses an alternative to manage renal transplant patients.

Benefits Derivated From Late Steroid Withdrawal in Renal Transplant Recipients

Because corticosteroids have adverse metabolic effects, inducing bone-mineral imbalance and contributing to infections among renal transplant recipients, many withdrawal trials have been attempted to reduce adverse events and improve quality of life. We retrospectively analyzed the safety and efficacy of late steroid withdrawal, after the first posttransplant year, among a selected group of kidney allograft recipients. In 42 low immunological risk allograft recipients, among 382 patients transplanted during a decade, corticosteroids were progressively reduced and completely withdrawn. The evolution of clinical and biochemical parameters after the withdrawal were analyzed. Corticosteroid withdrawal was performed as a mean of 52.16 +/- 28.41 months posttransplant, with subsequent follow-up without steroid treatment of 18.13 +/- 16.11 months. Comparing the most recent evaluation with the data previous to steroid withdrawal, patients showed a significant decreases in diastolic pressure (P = .039), total cholesterol (P = .000), and low-density lipoprotein cholesterol levels (P = .039), but not in triglyceride levels (P = .33). Body weight did not change (P = .77), but increased fasting glucose levels were noted (P = .03), in absence of new diagnosed diabetes mellitus. A significant reduction in cyclosporine Neoral (P = .01) or tacrolimus doses were detected (P = .01). At the last visit, serum creatinine in the whole group remained stable (P = .06). Only five patients showed an increase in serum creatinine more than 20% (from 1.44 +/- 0.41 to 1.94 +/- 0.45 mg/dL P = .04) and proteinuria did not increase (P = .94). No patient was diagnosed with a rejection episodes or required corticosteroid resumption. Graft and patient survivals were 100% at the end of follow-up. In conclusion, our data showed that late corticosteroid withdrawal in renal transplant recipients of low immunological risk is safe and is followed by an improvement in their metabolic profile and in blood pressure.

[Seasonal perodicity in vascular access thrombosis for haemodialysis]

Different studies have shown that some clinical events, particularly cardiovascular and thrombotic events, show a regularity in its appearance. The aim of our study was to analyse the possible existence of seasonal periodicity in the incidence of the vascular access thrombosis in patients on chronic haemodialysis. Prospectively, we collected information of 164 patients with 250 episodes of vascular access thrombosis referred to our hospital from january 1995 to december 1999. An ANOVA test for comparison of the means, and a time series analysis were performed. During the five year study the consecutive number of thrombosis were 43, 57, 55, 59 and 36. When the different seasons were analysed, the cumulative number of events in summer during the study period were 91, a significant increase compared to spring, autumn, and winter (54, 54, and 51, respectively; p<0.001). Time series analysis confirmed that thrombolic events during summer showed an increased incidence over the mean (p<0.001), and it occurred every year. The same results were obtained when the PTFE grafts were analyzed separetely (july RR 2.62, p=0.002; august, RR 2.37, p=0.04), but not with the arteriovenous fistulae. In conclusion, this study showed a seasonal periodicity of vascular access thrombosis, with a PTFE graft. Although the causes were unknown, these data alert us on the convenience of an increased attention to the vascular access during the summer months in order to prevent its thrombosis.

Erythropoietin treatment in the sixth posttransplant month as a prognostic factor for renal allograft survival

The purpose of this work was to assess the prognostic value of the need for erythropoietin (EPO) treatment at 6 months after transplantation. We retrospectively reviewed the outcomes of 143 consecutive cadaveric kidney transplants performed between January 2000 and April 2004, functioning at 6 months postransplantation. Patients were divided into two groups: group EPO6m (n = 24) received EPO treatment in the sixth month, and a control group (n = 119) did not receive EPO. Renal function deterioration (RFD) was considered to be a sustained decrease in creatinine clearance (CrCl) greater than 20% between the sixth month postransplant and the last visit. Mean follow-up was 38 +/- 16 months. The mean ages of the donor (57 +/- 9 vs 49 +/- 12 years; P = .001) and the recipient (59 +/- 12 vs 47 +/- 17 years; P = .000) were greater in the EPO6m group. Delayed graft function (83% vs 48%; P = .001) was more frequent in the EPO6m group. At 6 months after transplantation the EPO6m group showed lower hemoglobin (11.52 +/- 1.71 vs 13.32 +/- 1.69 g/dL; P = .000), higher serum creatinine (2.31 +/- 0.72 vs 1.65 +/- 0.53 mg/dL; P = .000), lower CrCl (33.53 +/- 10.83 vs 53.6 +/- 17.58 mL/min; P = .000), and similar proteinuria. RFD was more common in the EPO6m group (38% vs 10%; P = .026), with a different pattern of evolution of CrCl (-0.098 +/- 0.176 vs +0.093 +/- 0.396 mL/min/mo, P = .000). Multivariate analysis demonstrated that treatment with EPO at 6 months was the only predictor of RFD (RR 4.46; 1.58 to 12.58; P = .005). The need for EPO at 6 months postransplant was a good predictor of later renal allograft deterioration, more sensitive than serum creatinine or proteinuria.

Transplant Renal Artery Stenosis: Association With Acute Vascular Rejection

BACKGROUND

Transplant renal artery stenosis, the prevalence of which varies from 2% to 12%, is an important cause of hypertension and allograft dysfunction. We sought to determine the clinical characteristics of this disorder, assessing, predisposing factors, establishing treatment options, and examining patient outcomes.

PATIENTS AND METHODS

Among 321 renal allograft recipients between November 1996 and December 2004, six patients were identified with this finding. We analyzed their clinical data before and after treatment compared with the 315 recipients face of the disorder.

RESULTS

The six patients with the disorder were diagnosed within the first year (2 to 8 months; median 5.5 months). All patients displayed renal dysfunction, peripheral edema, and new-onset or uncontrolled hypertension at presentation. Abnormal Doppler findings were observed in 5 (83.3%) patients. The hemodynamically significant stenosis was successfully treated with percutaneous transluminal angioplasty (PTA) in all six. However, 3 (50%) patients displayed recurrent stenosis requiring a second PTA. The mean serum creatinine level decreased from a pre-PTA value of 4.4 +/- 1.8 mg/dL to a 1-month post-PTA value of 2.2 +/- 0.5 mg/dL (P = .027). Patients had no significant improvement in mean systolic and diastolic pressure. Vascular acute rejection episodes were more frequent among the affected than the control group (3/6; 50% vs 18/315; 5.7%; P < .001). No differences were found in age, sex, donor type, etiology of renal disease, immunosuppression, acute tubular necrosis, acute cellular rejection, cold ischemia time, or HLA matching.

CONCLUSION

Transplant renal artery stenosis is a common cause of hypertension and renal allograft dysfunction. Acute vascular rejection is associated with this disorder.

[Chronological aggregation of subcutaneous mycosis in renal transplant recipients]

We present four cases of subcutaneous invasive mycosis in renal transplant recipients that happened in our Unit during a period of eight months. The Microbiology Department did not find any fungi when they studied possible reservoirs and vectors for transmission. We speculate about the reasons of this chronological aggregation. We discuss the treatment that we used for these infections.

[Renal transplantation with positive crossmatch]

INTRODUCTION

Lymphocytotoxic antibodies reduce the expectancy of renal transplantation due to the increased risk of a positive crossmatch.

MATERIAL AND METHODS

We analyzed the evolution of eight kidney transplants performed in our unit in presence of a positive crossmatch with historical T and/or B lymphocyte positive crossmatches.

RESULTS

Mean panel reactivity was 76,6 +/- 25,7% (r: 22-100%), been higher than 75% in six patients. Six patients were recipients of a second or third transplant. Immunosuppression consisted of quadruple therapy including induction with thymoglobuline. Five patients had delayed graft function, and one had primary non-function of the graft. One patient lost her graft due to chronic allograft nephropathy in the second year postransplantation. Six patients maintained a good renal function (serum creatinine 1,2 +/- 0,5 mg/dl, proteinuria 0,20 +/- 0,34 g/day).

CONCLUSION

Renal transplantation in presence of a positive cross-match with historical serum and T lymphocytes and/or B lymphocytes, was followed by a satisfactory graft survival.

Use of Neoral C2 monitoring: a European consensus

Large-scale clinical trials using C(2) monitoring of cyclosporine (CsA) microemulsion (Neoral) in renal transplant recipients have demonstrated low acute rejection rates and good tolerability with a low adverse event profile in a variety of settings: with or without routine induction therapy; in combination with mycophenolate mofetil; with standard-exposure or low-exposure Neoral; and in patients with immediate or delayed graft function. In liver transplantation, C(2) monitoring significantly reduces the severity and incidence of acute rejection compared with C(0) monitoring, without adverse consequences in terms of renal function or tolerability. Different C(2) targets are appropriate depending on adjunctive immune suppression, level of immunologic risk, CsA tolerability, risk of renal toxicity and time since transplantation. CsA absorption may increase substantially in most patients during the first 1-2 weeks post-transplant, and this should be taken into account to avoid overshooting C(2) target range. A patient with a low C(2) value may be either a low or a delayed absorber of CsA, or be a normal absorber who is receiving too low a dose of Neoral. C(2) monitoring alone is insufficient to differentiate between these types of patients, and measurement of additional timepoints is recommended. Adopting C(2) monitoring in maintenance transplant patients identifies those who are overexposed to CsA. In summary, randomized, prospective, multicenter studies and single-center trials have evaluated Neoral C(2) monitoring within a range of regimens in different organ types, providing a robust evidence base for the benefits of this sensitive monitoring technique.

[Post-transplant diabetes mellitus associated with acute hepatitis C virus infection in a renal transplant recipient]

There are some controversial reports about the pathogenic role of hepatitis C virus infection on diabetes mellitus in renal graft recipients. We report a case of a renal transplanted who developed diabetes mellitus post-transplantation during an acute hepatitis C virus infection. We discuss the multifactorial etiology of post-transplant diabetes mellitus, and the possible interaction between tacrolimus and an acute virus C infection on its pathogenesis.

Clinical outcomes during the first three months posttransplant in renal allograft recipients managed by C2 monitoring of cyclosporine microemulsion

BACKGROUND

MO2ART (monitoring of 2-hr absorption in renal transplantation) is the first prospective, multicenter trial of cyclosporine (CsA) blood level 2 hr postdose (C2) monitoring in de novo kidney recipients receiving CsA microemulsion (ME) (Neoral; Novartis, Basel, Switzerland). Efficacy and safety results from the first 3 months are presented here.

METHODS

MO2ART is a 12-month, open-label, randomized study involving 296 patients. In all patients, the dose of CsA-ME was adjusted to achieve protocol-defined C2 targets of 1.6 to 2.0 microg/mL for the first month, with subsequent tapering. Randomization into two target groups occurred at 3 months. All patients received steroids and mycophenolate mofetil (89%) or azathioprine. For patients with delayed graft function, the protocol permitted reduced C2 targets and prophylactic administration of antibodies.

RESULTS

At 3 months, overall incidence of biopsy-proven acute rejection was 11.5%. Median serum creatinine was 132 micromol/L. Patient and graft survival were 96.6% and 91.2%, respectively. C2 levels greater than 1.6 microg/mL were achieved within 5 days by 60.6% of patients with immediate graft function and 19.5% of patients with delayed graft function. Prophylactic antibodies were used in 15% of the total population. Twenty-four patients (8.1%) experienced serious adverse events with a suspected relation to CsA, and 26 patients (8.8%) discontinued the study because of adverse events (n=15) or after a switch in immunosuppression after rejection episodes (n=11).

CONCLUSIONS

Patient management by C2 monitoring resulted in a low incidence of biopsy-proven acute rejection in standard risk de novo kidney recipients, 85% of whom did not receive prophylactic antibodies. CsA-ME with C2 monitoring provides excellent short-term efficacy and safety among de novo renal transplant patients.

[Prognostic significance of programmed dialysis in patients who initiate renal substitutive treatment. Multicenter study in Spain]

BACKGROUND

The aim of our study was to analyse patient characteristics, mortality and costs, all of them in relation to whether starting dialysis was planned or unplanned.

METHODS

A total of 362 patients (227 male and 135 female) from five hospitals of the National Health System, who were started on chronic renal replacement therapy (RRT) during 1996 and 1997 were included. Patients who were started on RRT after acute renal failure were excluded. We carried out a retrospective analysis of the demographic characteristics, patients' conditions at the time of initiating dialysis and outcome and costs at six and thirty-six months of treatment. Patients were classified as planned (PL-D) or unplanned dialysis (UNPL-D), depending on whether or not the patient had a vascular or peritoneal access ready to use for initiating RRT.

RESULTS

One hundred and eighty-six patients (51.4%) started on dialysis in the PL-D group whereas 176 (48.6%) did it as UNPL-D. In this latter group, 135 (37.3% of the total) had previously been monitored by a nephrologist, and 41 (11.3%) initiated dialysis without previous nephrological follow-up. UNPL-D was associated with older age (p < 0.001), non-nephrological follow-up (p < 0.001), diabetes (34.7% vs 22.6%) (p = 0.011), haemodialysis as a first mode of RRT (94.9 vs 81.7%) (p < 0.001), higher comorbidity risk (p < 0.001), dialysis initiation with uraemic symptoms or fluid overload (p < 0.001), increased blood transfusion requirement (p < 0.001) and lower serum albumin (p < 0.001), creatinine clearance (p < 0.001), haemoglobin concentration (p < 0.001), and weight (p = 0.002). In the PL-D group the main primary renal diseases were glomerular and polycystic disease, whereas interstitial and diabetic nephropathy were higher in UNPL-D group (p = 0.005). Multivariate analysis showed that previous non nephrological follow-up, uraemic symptoms, interstitial nephritis as primary renal disease correlated with UNPL-D initiation, and it was followed by choosing haemodialysis as first RRT. UNPL-D was also associated with increased number of days of hospitalization at the initiation of dialysis, and during the first 6 months (p < 0.001), increase of hospitalization days (p = 0.009), and increased 6-month-mortality (10.2% vs 3.2%) (p = 0.015, log rank test), and three-year mortality (24.2 vs 36.9%) (p = 0.006, log rank test). The costs of UNPL-D were fivefold that of the PL-D group.

CONCLUSION

UNPL-D has been associated with worse overall clinical conditions at the initiation of chronic replacement therapy, choosing haemodialysis as first RRT, increased morbi-mortality and subsequent increase of costs.

[Endoluminal percutaneous thrombectomy as a treatment for acute vascular access thrombosis: long-term results of 123 procedures]

Percutaneous treatment of thrombosis of occluded vascular access (VA) for haemodialysis (HD) has been an alternative to surgical and pharmacological treatments, but long term results are not well defined. The aim of our study was to analyse the long term results of percutaneous thrombectomy as a treatment of occluded VA for HD. We conducted a prospective study from june 1995 to april 1999, including 123 consecutive thrombectomies in 64 VA in patients submitted to our hospital because of recent thrombosis of VA for HD. We used two different techniques, hydrodynamic catheter thrombectomy (Hydrolyser) in the 42 first procedures (34.1%), and since october 1996 we used mechanical balloon thrombolysis in the remaining 81 patients (65.9%). Underlying stenoses were evaluated by angiography, and treated by angioplasty. After the procedure, intravenous heparin was administered for 24 hours. The VA were 28 Brescia-Cimino arteriovenous fistulae (30.4%) and 64 PTFE grafts (69.6%).

PATIENT CHARACTERISTICS

mean age: 63 +/- 15 years (18-84), previous VA: 3.3 +/- 2.5 (0-9). The mean follow-up was 10.5 +/- 8.6 months (3-35). Percutaneous thrombectomy was able to remove the clots in 120 instances (technical success: 97.5%). After the thrombectomy 15 patients (16.3%) were immediately referred to the surgeon to perform a new VA due to vascular lesions in which percutaneous treatment was not indicated. Thirteen cases (14.1%) showed early thrombosis (< 72 hours). During the follow-up, 27 cases developed thrombosis (30%) and 26 VA were still patent (28.3%). In 23% of perfusion lung scans and in 2 of the 5 angiographies performed after thrombectomy, subsegmentary or segmentary perfusion defects were detected, without clinical significance. There were no relevant undesirable effects related to the technique and no symptomatic pulmonary embolism. In summary, percutaneous thrombectomy, whether hydrodynamic or mechanical, has shown to be an efficacious treatment of VA thrombosis for HD, preserving the VA with satisfactory long-term results.