Inhibition of JAK3 and PKC via Immunosuppressive Drugs Tofacitinib and Sotrastaurin Inhibits Proliferation of Human B Lymphocytes In Vitro

BACKGROUND

Antibody-mediated response in solid organ transplantation is critical for graft dysfunction and loss. The use of immunosuppressive agents partially inhibits the B-lymphocyte response leading to a risk of acute and chronic antibody-mediated rejection. This study evaluated the impact of JAK3 and PKC inhibitors tofacitinib (Tofa) and sotrastaurin (STN), respectively, on B-cell proliferation, apoptosis, and activation in vitro.

METHODS

Human B cells isolated from peripheral blood of healthy volunteers were cocultured with CD40 ligand-transfected fibroblasts as feeder cells in the presence of interleukin (IL) 2, IL-10, and IL-21. The cocultures were treated with immunosuppressants Tofa, STN, and rapamycin (as a control), to analyze the proliferation and apoptosis of B cells by means of Cyquant and flow cytometry, respectively. CD27 and IgG staining were applied to evaluate whether treatments modified the activation of B cells.

RESULTS

Tofa and STN were able to inhibit B-cell proliferation to the same extent as rapamycin, without inducing cell apoptosis. After 6 days in coculture with feeder cells, all B cells showed CD27 memory B-cell phenotype. None of the immunosuppressive treatments modified the proportion between class-switched and non-class-switched memory B cells observed in nontreated cultures. The high predominance of CD27⁺CD24⁺ phenotype was not modified by any immunosuppressive treatment.

CONCLUSIONS

Our results show that Tofa and STN can suppress B-cell antibody responses to an extent similar to rapamycin, in vitro; therefore these compounds may be a useful therapy against antibody-mediated rejection in transplantation.

Desensitization in ABO-Incompatible Kidney Transplantation With Low ABO Iso-Agglutinin Titers

BACKGROUND

In ABO-incompatible (ABOi) kidney transplantation (KT) with low iso-agglutinin (IG) titers (IGT), standard pre-conditioning treatment might be excessive. To try to answer this question, we evaluated the pre-conditioning requirements of a group of ABOi KT with low ABO IGT in our center. Our main objective was to assess desensitization requirements for ABOi KT with low IGT (<16) at Hospital Clinic of Barcelona from 2006 to 2014.

METHODS

A retrospective study of desensitization (rituximab and plasma exchange [PE]) requirements for ABOi KT with IGT <16 was conducted.

RESULTS

One and 5 years after KT, patient survival was 100%. Renal graft survival was 90% at 1 and 5 years after KT. Mean PE performed before KT was 1.7 (standard deviation [SD], 1.703); 50% of the patients did not receive PE after transplantation, 30% received 2 sessions of PE, and 20% received only 1. The average is 0.8 (SD, 0.91).Follow-up IG determinations remained with low titers (≤8/8). No rebounds of titers were observed during the first 4 to 6 months after transplantation.

CONCLUSIONS

Recipients with IGT ≤8 required none or only 1 PE session to reach acceptable titers (titers ≤4) to perform ABOi KT safely. This information is useful to assess the possibility of a minimized desensitization protocol in ABOi KT donors with low titers of IG to reduce adverse effects, reduce cost, and simplify pre-transplant logistics.

Living Donor Transplantation: Long-Term Evolution Related to Age Matching

The lack of donors is favoring living kidney donor (LKD) transplantation worldwide, quite often beyond the classic age-matching rules. We analysed renal function (RF) at 1 and 5 years in all donor and recipients as well as death-censored graft and patient survival. LKD recipients were divided into 4 subgroups: young recipients-young donors (YR-YD; N = 355), elderly recipients-young donors (ER-YD; N = 13), young recipients-elderly donors (YR-ED; N = 67), and elderly recipients-elderly donors (ER-ED; N = 38). "Elderly" was defined as ≥60 years. RF was better in those who received a young allograft (YR-YD/ER-YD) at any time (P < .001). There was a trend toward higher proteinuria among the recipients of an old allograft (YR-ED/ER-ED) at any time (P = not significant [NS]). However, our population showed low levels of proteinuria and this was not a risk factor for graft failure. Logistic regression model showed that creatinine level at 1 year is a good predictor of graft losses. Graft survival was worse in the allografts from elderly donors (P < .001). Analysing the young recipients, renal survival was inferior in those who received an old kidney (YR-ED; P < .00005) as well as mortality rates at 14 years (P = .03). The RF of young (N = 295) and elderly donors (N = 98) was optimal with no progression to ESRD or deaths registered during follow-up. In conclusion, young recipients of elderly kidneys pay the price of a worse RF, allograft prognosis, and patient prognosis. The pair YR-ED is a doable option, but we recommend age matching when it is possible.

Cyclosporine A Inhibits the T-bet-Dependent Antitumor Response of CD8(+) T Cells

Transplant recipients face an increased risk of cancer compared with the healthy population. Although several studies have examined the direct effects of immunosuppressive drugs on cancer cells, little is known about the interactions between pharmacological immunosuppression and cancer immunosurveillance. We investigated the different effects of rapamycin (Rapa) versus cyclosporine A (CsA) on tumor-reactive CD8(+) T cells. After adoptive transfer of CD8(+) T cell receptor-transgenic OTI T cells, recipient mice received either skin grafts expressing ovalbumin (OVA) or OVA-expressing B16F10 melanoma cells. Animals were treated daily with Rapa or CsA. Skin graft rejection and tumor growth as well as molecular and cellular analyses of skin- and tumor-infiltrating lymphocytes were performed. Both Rapa and CsA were equally efficient in prolonging skin graft survival when applied at clinically relevant doses. In contrast to Rapa-treated animals, CsA led to accelerated tumor growth in the presence of adoptively transferred tumor-reactive CD8(+) OTI T cells. Further analyses showed that T-bet was downregulated by CsA (but not Rapa) in CD8(+) T cells and that cancer cytotoxicity was profoundly inhibited in the absence of T-bet. CsA reduces T-bet-dependent cancer immunosurveillance by CD8(+) T cells. This may contribute to the increased cancer risk in transplant recipients receiving calcineurin inhibitors.

Polyclonal versus monoclonal induction therapy in a calcineurin inhibitor-free immunosuppressive therapy in renal transplantation: a comparison of efficacy and costs

BACKGROUND

Induction therapy in renal transplantation reduces the incidence of acute rejection (AR) in expanded criteria donation (ECD) and donation after cardiac death (DCD). We compared the efficacy of Thymoglobulin (Sanofi-Aventis, Spain), ATG Fresenius (ATG-Fresenius, Spain), and Simulect (Novartis Farm, Spain) in a calcineurin-free protocol in ECD and DCD renal transplantation by evaluating patient survival, graft survival, and AR at 1 year and overall costs.

METHODS

An observational retrospective study was performed using our database of 289 consecutive cadaveric ECD renal transplant recipients (n = 178) and DCD recipients (n = 111) from April 1999 to December 2011. Induction therapy consisted of Simulect, Thymoglobulin, and ATG Fresenius. Calcineurin-inhibitor (CNI)-free maintenance therapy consisted of mycophenolate mofetil or sodium and steroids.

RESULTS

There were no differences in the patients' demographic characteristics or patient and graft survival. One-year AR rates were equivalent (ECD: 10%, 19.1%, 17.7% versus DCD: 14.3%, 7.1%, 16.7%). Leukopenia and thrombopenia were significantly more frequent in the ECD group treated with polyclonal induction. The average total cost of transplantation was higher in the ECD group but there were no significant differences in the average total cost between ECD and DCD: 39,970.31 ± 7,732€ versus 35,058.34 ± 6,801€ (P = NS).

CONCLUSION

Our study shows the same efficacy with polyclonal and monoclonal antibody induction and a CNI-free treatment regimen in ECD and DCD renal transplantation with no differences in overall costs at 1 year after transplantation.

Association between individual and combined SNPs in genes related to innate immunity and incidence of CMV infection in seropositive kidney transplant recipients

In this study, we assessed the association between single-nucleotide polymorphisms (SNPs) in seven candidate genes involved in orchestrating the immune response against cytomegalovirus (CMV) and the 12-month incidence of CMV infection in 315 CMV-seropositive kidney transplant (KT) recipients. Patients were managed either by antiviral prophylaxis or preemptive therapy. CMV infection occurred in 140 patients (44.4%), including 13 episodes of disease. After adjusting for various clinical covariates, patients harboring T-allele genotypes of interleukin-28B (IL28B) (rs12979860) SNP had lower incidence of CMV infection (adjusted hazard ratio [aHR]: 0.66; 95% confidence interval [CI]: 0.46-0.96; p-value = 0.029). In the analysis restricted to patients not receiving prophylaxis, carriers of the TT genotype of toll-like receptor 9 (TLR9) (rs5743836) SNP had lower incidence of infection (aHR: 0.61; 95% CI: 0.38-0.96; p-value = 0.035), whereas the GG genotype of dendritic cell-specific ICAM 3-grabbing nonintegrin (DC-SIGN) (rs735240) SNP exerted the opposite effect (aHR: 1.86; 95% CI: 1.18-2.94; p-value = 0.008). An independent association was found between the number of unfavorable SNP genotypes carried by the patient and the incidence of CMV infection. In conclusion, specific SNPs in IL28B, TLR9 and DC-SIGN genes may play a role in modulating the susceptibility to CMV infection in CMV-seropositive KT recipients.

Elimination of large uremic toxins by a dialyzer specifically designed for high-volume convective therapies

BACKGROUND

Unlike conventional hemodialysis treatments, which rely almost solely on diffusion-related mechanisms for solute removal, hemodiafiltration (HDF) allows more efficient removal of higher molecular weight toxins due to convective transport mechanisms. To facilitate the removal of these toxins in HDF treatment modalities, dialyzers with highly efficient high-flux membranes are necessary. This study assessed the large uremic toxin removal ability of a high-flux dialyzer (FX CorDiax 60) specifically designed to facilitate convective therapies compared with a standard high-flux dialyzer (FX 60).

METHODS

In an open, randomized, cross-over, single-center, controlled, prospective clinical study, 30 adult chronic hemodialysis patients were treated by post-dilution online HDF with the FX 60 or the FX CorDiax 60 dialyzer. All other dialysis parameters were kept constant in both study arms. The reduction rate (RR) of blood urea nitrogen, phosphate, β2-microglobulin (β2-m), myoglobin, prolactin, α1-microglobulin, α1-acid glycoprotein, albumin and total protein as well as the elimination into dialysate was intraindividually compared for the two dialyzer types.

RESULTS

For FX CorDiax 60 versus FX 60, the RR was significantly higher for blood urea nitrogen (86.23 ± 4.14 vs. 84.89 ± 4.59%, p = 0.015), β2-m (84.67 ± 3.79 vs. 81.30 ± 4.82%, p < 0.0001), myoglobin (75.23 ± 10.48 vs. 58.60 ± 12.1%, p < 0.0001), prolactin (72.96 ± 9.68 vs. 56.91 ± 13.01%, p < 0.0001) and α1-microglobulin (20.89 ± 18.27 vs. 13.60 ± 12.50%, p = 0.016). There were no significant differences in the RR for phosphate, α1-acid glycoprotein, albumin and total protein. Mass removal was significantly higher with the FX CorDiax 60 than with the FX 60 for β2-m (0.26 ± 0.09 vs. 0.24 ± 0.09 g, p = 0.0006), myoglobin (1.83 ± 0.89 vs. 1.51 ± 0.76 mg, p = 0.0017), prolactin (0.17 ± 0.13 vs. 0.14 ± 0.08 mg, p = 0.02) and albumin (4.25 ± 3.49 vs. 3.01 ± 2.37 g, p = 0.03).

CONCLUSIONS

This study demonstrates that treating patients with an FX CorDiax 60 instead of an FX 60 dialyzer in post-dilution HDF mode significantly increases the elimination of middle molecules.

Sotrastaurin in calcineurin inhibitor-free regimen using everolimus in de novo kidney transplant recipients

Sotrastaurin, a novel selective protein-kinase-C inhibitor, inhibits early T cell activation via a calcineurin-independent pathway. Efficacy and safety of sotrastaurin in a calcineurin inhibitor-free regimen were evaluated in this two-stage Phase II study of de novo kidney transplant recipients. Stage 1 randomized 131 patients (2:1) to sotrastaurin 300 mg or cyclosporine A (CsA). Stage 2 randomized 180 patients (1:1:1) to sotrastaurin 300 or 200 mg or CsA. All patients received basiliximab, everolimus (EVR) and prednisone. Primary endpoint was composite efficacy failure rate of treated biopsy-proven acute rejection, graft loss, death or lost to follow-up. Main safety assessment was estimated glomerular filtration rate (eGFR) by MDRD-4 at Month 12. Composite efficacy failure rates at 12 months were higher in sotrastaurin arms (Stage 1: 16.5% and 10.9% for sotrastaurin 300 mg and CsA; Stage 2: 27.2%, 34.5% and 19.4% for sotrastaurin 200 mg, 300 mg and CsA). eGFR was significantly better in sotrastaurin groups versus CsA at most time points, except at 12 months. Gastrointestinal and cardiac adverse events were more frequent with sotrastaurin. Higher treatment discontinuation, deaths and graft losses occurred with sotrastaurin 300 mg. Sotrastaurin combined with EVR showed higher efficacy failure rates and some improvement in renal allograft function compared to a CsA-based therapy.

Three-year outcomes from BENEFIT-EXT: a phase III study of belatacept versus cyclosporine in recipients of extended criteria donor kidneys

Recipients of extended-criteria donor (ECD) kidneys have poorer long-term outcomes compared to standard-criteria donor kidney recipients. We report 3-year outcomes from a randomized, phase III study in recipients of de novo ECD kidneys (n = 543) assigned (1:1:1) to either a more intensive (MI) or less intensive (LI) belatacept regimen, or cyclosporine. Three hundred twenty-three patients completed treatment by year 3. Patient survival with a functioning graft was comparable between groups (80% in MI, 82% in LI, 80% in cyclosporine). Mean calculated GFR (cGFR) was 11 mL/min higher in belatacept-treated versus cyclosporine-treated patients (42.7 in MI, 42.2 in LI, 31.5 mL/min in cyclosporine). More cyclosporine-treated patients (44%) progressed to GFR <30 mL/min (chronic kidney disease [CKD] stage 4/5) than belatacept-treated patients (27-30%). Acute rejection rates were similar between groups. Posttransplant lymphoproliferative disorder (PTLD) occurrence was higher in belatacept-treated patients (two in MI, three in LI), most of which occurred during the first 18 months; four additional cases (3 in LI, 1 in cyclosporine) occurred after 3 years. Tuberculosis was reported in two MI, four LI and no cyclosporine patients. In conclusion, at 3 years after transplantation, immunosuppression with belatacept resulted in similar patient survival, graft survival and acute rejection, with better renal function compared with cyclosporine. As previously reported, PTLD and tuberculosis were the principal safety findings associated with belatacept in this study population.

Proliferation signal inhibitors and post-transplant malignancies in heart transplantation: practical clinical management questions

Although malignancy is a major threat to long-term survival of heart transplant (HT) recipients, clear strategies to manage immunosuppression in these patients are lacking. Several lines of evidences support the hypothesis of an anticancer effect of proliferation signal inhibitors (PSIs: mammalian target of rapamycin [mTOR] inhibitors) in HT recipients. This property may arise from PSI's ability to replace immunosuppressive therapies that promote cancer progression, such as calcineurin inhibitors or azathioprine, and/or through their direct biological actions in preventing tumor development and progression. Given the lack of randomized studies specifically exploring these issues in the transplant setting, a collaborative group reviewed current literature and personal clinical experience to reach a consensus aimed to provide practical guidance for the clinical conduct in HT recipients with malignancy, or at high risk of malignancy, with a special focus on advice relevant to potential role of PSIs.

Erythropoietin resistance as surrogate marker of graft and patient survival in renal transplantation: 3-year prospective multicenter study

BACKGROUND

Some transplant recipients demonstrate an inadequate response to erythropoiesis-stimulating agents, or so-called erythropoietin (Epo) resistance. The cause is multifactorial. Resistance to EPO may entail a poor prognosis for the graft and the patient, although results in the literature are inconsistent, and long-term follow-up is lacking.

OBJECTIVE

To evaluate whether the presence of Epo resistance at the beginning of the study was a predictive factor for graft and patient survival.

MATERIALS AND METHODS

From 482 renal transplant recipients (Kidney Disease Outcomes Quality Initiative stage 3-4T) receiving Epo-stimulating agents in the Anemia and Renal Transplantation in Spain study, 101 were selected for the present study. Erythropoietin resistance was defined as a ratio of weekly Epo dosage/hemoglobin concentration>486,94 U/g/dL with a hemoglobin/<11 g/dL. Darbepoetin dosage was calculated in Epo equivalent units, with a 1:200 conversion factor. Patients were grouped as Epo-resistant (ER+) or not Epo-resistant (ER-), to assess whether Epo resistance was predictive of patient and graft survival.

RESULTS

There were no differences in demographic data between the 2 groups except for a higher incidence of vascular, interstitial, and diabetes-related causes of chronic renal failure in the ER+ group. At 3 years posttransplantation, graft survival was 33% in the ER+ group vs 58% in the ER- group (P=.06), and patient survival was 52% in the ER+ group vs 88% in the ER- group (P=.008). Using a Cox regression model, at 3 years, the relative risk of graft failure was 1.96 in the ER+ group (95% CI, 0.93-3.12; P=.07), and of patient death was 3.9 (95% confidence interval, 1.30-11.63; P=.01).

CONCLUSION

Erythropoietin resistance is an independent risk factor for death after renal transplantation.

Long-term maintenance therapy with calcineurin inhibitors: an update

Combination therapy with mammalian target of rapamycin (mTOR)-inhibitors and calcineurin inhibitors (CNIs) provides significant immunosuppressive efficacy. If the combination of these agents is not properly optimized, however, important risks for synergistic toxicity and long-term complications may result. The combination of a CNI and an mTOR-inhibitor is a potent immunosuppressive therapy that effectively prevents the incidence of acute rejection, although the potential nephrotoxic impact must be considered in the longer term. The trend has therefore been to use a low-dose CNI in combination with the mTOR-inhibitor sirolimus in order to reduce the risk of nephrotoxicity. Recent studies show that an mTOR-inhibitor/low-dose CNI combination is effective in the short term following transplantation, and over time, consideration should be given to the elimination of the CNI in order to preserve renal function. In the medium to long term, it is also possible to consider the elimination of steroids from such a protocol. Considering CNI dose minimization or elimination is an essential component of this approach, as is the optimal dose and level of both drugs when used in combination.

Conclusions from the symposium

Despite the progressive improvement in the early outcomes of renal transplantation, longer-term outcomes such as graft and patient survival have changed little since the introduction of cyclosporine-based immunosuppression. The major causes of graft loss after the first year are, first, chronic allograft nephropathy (CAN), and, second, death with a functioning graft. Kidney transplant recipients are not a homogenous population and so careful consideration is needed to individualize care in order to reduce the risk of cardiovascular disease and malignancy and improve long-term outcomes. A key component will be the consideration of the early and late phases of immunosuppression and the modification of immunosuppression in order to address the specific short- and long-term risks faced by each of our kidney transplant patients. The insights presented and discussed at this symposium will help to inform the design of new clinical strategies that may hold potential for improving the quality and quantity of life of the wide range of patients that we manage on a daily basis.

Comparative transcriptional and phenotypic peripheral blood analysis of kidney recipients under cyclosporin A or sirolimus monotherapy

Due to its low level of nephrotoxicity and capacity to harness tolerogenic pathways, sirolimus (SRL) has been proposed as an alternative to calcineurin inhibitors in transplantation. The exact mechanisms underlying its unique immunosuppressive profile in humans, however, are still not well understood. In the current study, we aimed to depict the in vivo effects of SRL in comparison with cyclosporin A (CSA) by employing gene expression profiling and multiparameter flow cytometry on blood cells collected from stable kidney recipients under immunosuppressant monotherapy. SRL recipients displayed an increased frequency of CD4 + CD25highFoxp3 + T cells. However, this was accompanied by an increased number of effector memory T cells and by enrichment in NFkB-related pro-inflammatory expression pathways and monocyte and NK cell lineage-specific transcripts. Furthermore, measurement of a transcriptional signature characteristic of operationally tolerant kidney recipients failed to detect differences between SRL and CSA-treated recipients. In conclusion, we show here that the blood transcriptional profile induced by SRL monotherapy in vivo does not resemble that of operationally tolerant recipients and is dominated by innate immune cells and NFkB-related pro-inflammatory events. These data provide novel insights on the complex effects of SLR on the immune system in clinical transplantation.

Long-term experience with kidney transplantation from hepatitis C-positive donors into hepatitis C-positive recipients

Kidney transplantation from hepatitis C virus (HCV) antibody positive donors (HCVD+) into HCV antibody positive recipients (HCVR+) is controversial. We implemented this policy in our units in 1990. Herein, we report the long-term safety of this strategy. From March 1990 to March 2007, 162 HCVR+ received a kidney from HCVD+ (group 1) and 306 from HCVD- (group 2) in our units. Mean follow-up was 74.5 months. Five-and 10-year patient survival was 84.8% and 72.7% in group 1 vs. 86.6% and 76.5% in group 2 (p = 0.250). Three deaths in group 1 and two in group 2 were liver-disease related. Five- and 10-year graft survival was 58.9% and 34.4% versus 65.5% and 47.6% respectively (p = 0.006) while death-censored graft survival was 69% and 47% versus 72.7% and 58.5% (p = 0.055). Decompensated chronic liver disease was similar: 10.3% versus 6.2%. Cox-regression analysis could not identify the donor's HCV serology as a significant risk factor for death, graft failure and severe liver disease in HCVR+. In conclusion, long-term outcome of HCVR+ transplanted with kidneys from HCVD+ seems good in terms of patient survival, graft survival and liver disease. HCVD+ was not a significant risk factor for mortality, graft failure and liver disease among HCVR+. These data strongly suggest that the use of kidneys from HCVD+ in HCVR+ is a safe long-term strategy that helps to prevent kidney loss.

[Dynamics of calcium-regulated PTH secretion in secondary hyperparathyroidism: comparison between "in vivo" vs. "in vitro" responses]

AIM

To compare the dynamics in vivo and in vitro calcium-PTH release of uremic patients with secondary hyperparathyroidism and their hyperplasic parathyroid glands after parathyroidectomy.

MATERIALS AND METHODS

Seven patients with secondary HPT and their 23 hyperplasic glands obtained after surgical parathyroidectomy were evaluated. In vivo studies of the PTH secretion curve were obtained by induction of hypocalcemia and hypercalcemia with a continuous endovenous infusion of sodium EDTA and Ca gluconate, respectively. For the in vitro studies, small parathyroid pieces of 1 mm were sequentially transferred to wells with varying Ca concentrations: 0.4, 0.6, 0.8, 1, 1.25 and 1.5 mM. iPTH concentrations were determined in the medium.

RESULTS

The in vivo set point did not correlate with the basal, maximal or minimal PTH concentrations, although it correlated significantly with the basal serum Ca concentration (r = 0.62, p < 0.02). Both in vivo and in vitro PTH secretion curves were sigmoidal, although the in vivo set point was higher than the in vitro (1.57 +/- 0.05 vs. 1.27 +/- 0.07 mM, p < 0.001). The degree of maximal PTH inhibition were similar in both circumstances (30.5 +/- 8.1 vs. 33.6 +/- 5.4 %; p = NS) with a significant direct correlation (r = 0.901; p < 0.01).

CONCLUSIONS

The in vivo set point of calcium is more closely related to serum calcium concentration than to basal iPTH concentration. Although there are differences between the in vivo and in vitro calcium set point the maximal degree of PTH inhibition was similar in both circumstances.

Minimizing the risk of posttransplant malignancy

Recent improvements in immunosuppressive therapies have reduced the incidence of acute rejection and increased patient survival. These agents may however contribute to higher rates of mortality due to an increased risk of cardiovascular disease or malignancy. Transplant patients are immunocompromised with a reduced ability to combat the development of malignancy. The higher risk for the activity of oncoviruses may also contribute to the higher incidence and determine specific tumor types. Some immunosuppressants seem to have direct oncogenic effects. In vitro data have demonstrated that calcineurin inhibitors (CNIs) may show direct effects on tumor growth and the development of metastases. In contrast, mTOR inhibitors have demonstrated anti-tumoral properties in vitro and perhaps potent anti-angiogenic effects thereby. Recent studies and registry analyses have confirmed that mTOR inhibitors are associated with a reduced incidence of malignancies. UNOS data demonstrated that an mTOR inhibitor, with or without a CNI, is associated with a reduced incidence of tumors compared to regimens without mTOR inhibitors. The Rapamune Maintenance Regimen study demonstrated that patients receiving sirolimus-based, CNI-free therapy after CsA withdrawal at 3 months showed a reduced incidence of malignancy at 5 years posttransplant, compared with those who continued on a regimen that included CsA. In the CONVERT study, patients converted to sirolimus revealed a significantly lower malignancy rate at 24 months (3.1%) compared with those who continued CNI-based therapy (9.8%, P < .001). The elimination of CNIs and the introduction of sirolimus may, therefore, have a role to reduce the risk of cancer among posttransplant patients.

Mammalian target of rapamycin and diabetes: what does the current evidence tell us?

New-onset diabetes mellitus after transplantation (NODAT) is a serious complication in organ transplantation; not only does it enhance the risk of graft dysfunction, it also increases cardiovascular morbidity and mortality. The mammalian target of rapamycin (mTOR) is regulated independently by insulin, amino acids, and energy sufficiency. It integrates signal from growth factors, hormones, nutrients, and cellular energy levels to regulate protein translation and cell growth, proliferation, and survival. In addition, mTOR generates an inhibitory feedback loop on insulin receptor substrate (IRS) proteins. Therefore, it was suggested that mTOR might link nutrient excess with both obesity and insulin resistance. In this review, we summarize the role of mTOR and its inhibitor sirolimus (SRL) on chronic hyperglycemia and insulin resistance in beta cells, adipose tissue, liver, and muscle. We further hypothesize, based on data from the literature and generated in our laboratory, that SRL could counteract the development of NODAT in stable glucose homeostasis due to its positive effects on insulin-stimulated glucose uptake, whereas in conditions that require an adaptive beta cell proliferation (such as pregnancy and weight increase), the administration of SRL might have effects that would promote the development of NODAT. Therefore, it seems crucial for patient outcome to consider these potentially contrasting effects of SRL.

Total hip arthroplasty in hemodialysis and renal transplant patients

Osteoarticular complications are common in patients with chronic renal failure and they often require implantation of a hip arthroplasty (total or partial) due to osteoarthritis, femoral neck fracture or ischemic necrosis of multifactor aetiology. Between 1992 and 2005 we operated on eighteen patients (23 hips) with chronic renal failure who were receiving renal replacement therapy (ten haemodialysis and eight renal transplants), and in each case either a total or partial hip arthroplasty was implanted. This group comprised nine women and nine men, with a mean age of 56 years (range: 30-83). Five cases were bilateral. The clinical diagnoses were necrosis (fourteen cases), femoral neck fracture (five cases) and osteoarthritis (three cases). The main early complications were haemorrhage in seventeen cases (74%) and infection in six cases (33%) (two urinary infections and four of the surgical wound). The late complications involved eight cases (35%) of prosthetic loosening (five aseptic and three septic). The surgery-related mortality rate was 17% (three cases). Prosthetic hip surgery in patients receiving renal replacement therapy is associated with high morbidity and mortality, thus highlighting the importance of careful patient selection.

Localising imaging in secondary hyperparathyroidism

Preoperative imaging has proved its use successful in the localization of solitary parathyroid adenomas in patients with suspected primary hyperparathyroidism. However, due to multiglandular disease at presentation patients with renal hyperparathyroidism need to be analyzed separately, making the usefulness of imaging techniques controversial. Recently, improved methods of functional imaging like parathyroid scan with 99mTc-sestamibi or positron emission tomography, especially when combined with computed tomography, can provide additional quantitative and qualitative information that has yet to be assessed. Nuclear medicine procedures could prove useful not only in preoperative diagnosis, but also in the selection of medical or surgical therapeutic alternatives in secondary hyperparathyroidism patients. There is evidence that 99mTc-sestamibi uptake in parathyroid hyperplasia or adenoma is related to biochemical markers of parathyroid function. We are only beginning to identify the factors involved in radiotracer uptake by parathyroid cells and how it can be modulated to obtain more accurate results. This review analyzes the current use of non-invasive imaging modalities in patients with secondary hyperparathyroidism, taking into account the latest trends in the field combining anatomic and functional modalities and the relevant factors linked to radiotracer uptake in abnormal hyperfunctioning parathyroid glands.

Risk factors for infection with extended-spectrum and AmpC beta-lactamase-producing gram-negative rods in renal transplantation

Increasing prevalence of infections caused by multiresistant gram-negative enteric bacilli due to synthesis of extended-spectrum beta-lactamase (ESBL) or to desrepressed chromosomic AmpC beta-lactamase (AmpC) is a major concern in the hospitalized patient population. Renal transplant recipients are especially susceptible to these infections. A cohort observational study in a 3-year period was performed. ESBL-production was determined by phenotypic analysis based on the CLSI recommendations. A multi-variate logistic regression analysis was performed to identify independent variables associated with multi-resistant gram-negative bacilli infection. The study included 417 patients (61 double kidney-pancreas recipients). The incidence of ESBL-producing and desrepressed chromosomic AmpC beta-lactamase resistance was 11.8% (49 patients). The most frequent bacteria isolated was E. coli (35/60 isolations), followed by Klebsiella spp(12/60 isolations). Double kidney-pancreas transplantation(OR 3.5, CI95% 1.6-7.8), previous use of antibiotics(OR 2.1,CI95% 1.1-4.1), posttransplant dialysis requirement (OR 3.1, CI95% 1.5-6.4) and posttransplant urinary obstruction (OR 5.8, CI95% 2.2-14.9) were independent variables associated with these multiresistant gram-negative enteric bacilli infections. The incidence of ESBL-producing and desrepressed AmpC beta-lactamase gram-negative enteric bacilli infection in our population was high. These infections are associated with significant morbidity after renal transplantation.

[How much should dialysis time be increased when catheters are used?]

The use of central catheters in hemodialysis patients as a permanent vascular access has increased during the last years, reaching numbers of around 7% of prevalent patients and between 25% of incident patients. Although the current catheters allow higher sanguineous flows with smaller incidence of infectious complications and dysfunction, the dose of dialysis that is reached is still inferior to that obtained with native arterio-venous fistula (AVF) and grafts. The aim of the present study was to evaluate the possible additional time supposed by dialysis using central venous catheters with respect to habitual vascular access as a consequence of the lesser blood flow (Qb) and the irregularity of its function (frequent lowering of the Qb and necessity of inverting the lines on many occasions). A total of 48 patients (31 men/17 women) with an average age of 61,6 +/- 14 years old (rank: 28-83), 20 with tunnelled catheter and the remaining with AVF, were included in the study. All the patients were dialyzed in the modality of high flux hemodialysis with a polisulphone of 1,9 m2 dialyzer, dialysis time of 240 minutes, dialysate flow 500 ml/min and monitors equipped with ionic dialysance (ID) with the objective of obtaining a Kt of 45 litres with each one of the different vascular accesses. The patients with AVF received 3 sessions, with variations of Qb to 300, 350 and 400 ml/min. The patients with tunnelled catheter received two sessions, to the maximum Qb, one with normal connection and other with inverted one. In the results obtained it is possible to emphasize that only the patients with AVF and 400 ml/min reached the objective of 45 L of Kt. The patients with AVF needed to increase 12 minutes of hemodialysis with a Qb of 350 ml/min and 28 minutes with a Qb of 300 ml/min; the catheters on normal position needed to increase 24 minutes and finally in the inverted catheters an increase of 59 minutes was necessary to reach the same Kt objective. We concluded that the patients dialyzed with central catheters on average needed to increase by 30 minutes the time of dialysis if the catheter worked in a normal position but 60 minutes if the arterio-venous lines were inverted so as to reach the minimum dose of dialysis.

Conversion from calcineurin inhibitors to sirolimus in kidney transplant patients reduces the urinary transforming growth factor-beta1 concentration

INTRODUCTION

Chronic allograft dysfunction (CAD) is the main cause of late transplant failure. Although several etiologies have been postulated, toxicity for calcineurin inhibitors (CNIs) is one of the most important causes of CAD, characterized by arteriolar hyalinosis, luminal narrowing, increased glomerulosclerosis, and tubulointerstitial damage. It's known that in transplant patients with CAD, fibrogenic mediators such as transforming growth factor beta (TGF-beta) are increased. Sirolimus is an immunosuppressive agent with a distinct mechanism of action compared with CNI.

AIM

This study assessed variations in levels of fibrogenic mediators among CAD patients treated with CNIs, before and after conversion to sirolimus.

PATIENTS AND METHODS

We studied twelve renal transplant patients with CAD on CNI treatment. TGF-beta in plasma and urine, endothelin-1, and vascular endothelial growth factor (VEGF) were studied before and 8 months after conversion to sirolimus treatment.

RESULTS

TGF-beta urine levels decreased from 24.7 +/- 11.2 to 12.8 +/- 5.1 ng/24 h (P = .049). In plasma, a similar decrease trend was observed (22.2 +/- 32 to 10.3 +/- 3 ng/mL), although it was not significant (P = .079). Endothelin-1 showed a decrease (8.1 +/- 3 to 5.2 +/- 1.1 pmol/L; P = .1) and VEGF in plasma increased from 34.3 +/- 37 to 92.2 +/- 86 pg/mL (P = .051).

CONCLUSIONS

Patients undergoing conversion from CNI to sirolimus treatment for CAD presented a significant decrease in TGF-beta urine levels, representing a decreased mediator of the CAD fibrogenic process.

Renal function in patients with cadaveric kidney transplants treated with tacrolimus or cyclosporine

INTRODUCTION

Renal function predicts graft survival in kidney transplant patients. This study compared the 2-year evolution of renal function in patients treated with cyclosporine or tacrolimus in combination with mycophenolate mofetil (MMF) and prednisone.

METHODS

We studied 1558 cadaveric renal transplant recipients from 14 Spanish hospitals between January 2000 and December 2002. Of these, 1168 were treated with tacrolimus and 390 with cyclosporine. The primary efficacy endpoint was long-term renal function. Renal function was measured by serum creatinine and glomerular filtration rate (GFR) by creatinine clearance calculated from the Cockcroft-Gault formula. This report summarizes the 2-year results.

RESULTS

At 24 months the tacrolimus group showed significantly better serum creatinine (1.5 +/- 0.7 vs 1.8 +/- 0.8 mg/dL, P < .001) and GFR (60.5 +/- 20.9 mL/min vs 47.9 +/- 10.0, P < .001) than the cyclosporine group. Additionally, recipients with ideal graft donors (23.5 +/- 2.8 vs 24.0 +/- 2.9 years) had a better serum creatinine at 2 years (1.23 +/- 0.2 vs 1.5 +/- 0.4 mg/dL, P < .05). Multivariate analysis showed that tacrolimus was an independent factor associated with better renal function: odds ratio 1.6, 95% confidence interval (1.2 to 2.2), P < .001.

CONCLUSIONS

Patients with a renal transplant treated with tacrolimus in combination with MMF and prednisone displayed better renal function at 2 years than those who received cyclosporine.

Early sirolimus use with cyclosporine elimination does not induce progressive proteinuria

Proteinuria has been reported in several papers after conversion from calcineurin inhibitors to Sirolimus (SRL), but this complication has not been analyzed in randomized clinical trials using de novo SRL. It is not known whether de novo use of SRL is a risk factor for proteinuria. We analyzed a series of patients included in a big multicenter randomized trial (RMR trial) corresponding to all patients in Spain and Portugal with respect to this issue. We retrospectively evaluated 24-hour proteinuria in all the patients during the study period (5 years postransplant) for comparison between treatment arms group A, continuous cyclosporine (CyA) + SRL and group B SRL with CyA elimination at 3 months postransplant. The elimination of CyA after the third month was not followed by significant changes in proteinuria. Nevertheless, during the last year of follow-up (between 48 and 60 months postransplant) an impressive increase in proteinuria was observed in group A. This surprising finding seemed to be a consequence of a protocol amendment that recommended CyA elimination in patients of group A, due to poorer results in the intermediate analysis of the trial. This fact suggests that the hemodynamic changes induced by elimination of the vasoconstrictor CyA might be responsible for the proteinuria but only in the long term probably when significant pathological lesions are already present. This finding argues for earlier conversion.

Effect of apolipoprotein E polymorphism on renal transplantation

INTRODUCTION

Dyslipidemia is an important cardiovascular risk factor and is implicated in the pathogenesis of chronic graft failure in renal transplant recipients. Apolipoprotein E (apoE), a hepatic glycoprotein involved in lipid metabolism, has been associated with hypercholesterolemia and premature coronary disease.

AIM

This study assessed the impact of apoE polymorphism on the evolution of renal transplant recipients.

METHODS

A total of 517 patients (age, 47 +/- 14 years; 62% men), who had undergone renal transplantation at least 12 months before enrollment, were assessed (mean follow-up, 5.4 +/- 2.2 years). ApoE polymorphisms (E2, E3, and E4 alleles) were analyzed using polymerase chain reaction (PCR) using genomic DNA. Donor-recipient clinical variables were assessed using univariate methods and Cox multivariate regression model.

RESULTS

Genotype frequency was as follows: E2/E2 <1%, E2/E3 10%, E3/E3 71%, E2/E4 2%, E3/E4 16%, and E4/E4 1%, with no differences between sexes. In the univariate study, E2/E4, E3/E4, and E4/E4 genotypes were related with poorer patient survival (P = .0045). In the multivariate study, the E4 allele was associated with a higher independent risk of graft loss (odds ratio [OR], 3.23; 95% confidence interval [CI], 1.44-7.21; P < .0001) and death of the patient (OR, 16.03; 95% CI, 3.28-75.18; P < .0001), but only in patients older than 60 years of age. In patients with the E4 allele, 45% of deaths were due to cardiovascular causes.

CONCLUSIONS

The genetic polymorphism of apoE (E4 allele) has an independent negative impact on patient and graft survival in the long term, particularly in older patients.

Molecular mechanisms of fibrillogenesis and the protective role of amyloid P component: two possible avenues for therapy

Amyloid deposits regress when the supply of fibril precursor proteins is sufficiently reduced, indicating that amyloid fibrils are degradable in vivo. Serum amyloid P component (SAP), a universal constituent of amyloid deposits, efficiently protects amyloid fibrils from proteolysis in vitro, and may contribute to persistence of amyloid in vivo. Drugs that prevent binding of SAP to amyloid fibrils in vivo should therefore promote regression of amyloid and we are actively seeking such agents. A complementary strategy is identification of critical molecular processes in fibrillogenesis as targets for pharmacological intervention. All amyloidogenic variants of apolipoprotein AI contain an additional positive charge in the N-terminal fibrillogenic region of the protein. This is unlikely to be a coincidence and should be informative about amyloidogenesis by this protein. The two amyloidogenic variants of human lysozyme, caused by the first natural mutations found in its gene, provide a particularly powerful model system because both the crystal structure and folding pathways of wild-type lysozyme are so well characterized. The amyloidogenic variant lysozymes have similar 3D crystal structures to the wild type, but are notably less thermostable. They unfold on heating, lose enzymic activity, and aggregate to form amyloid fibrils in vitro.

Erythropoietin Safety and Efficacy in Chronic Allograft Nephropathy

BACKGROUND

Patients with chronic allograft nephropathy (CAN) very frequently suffer anemia. Correction of anemia by means of recombinant erythropoietin (rEpo) is possible and useful, but safety and efficacy must be assessed.

METHODS

This multicenter, prospective, open study included patients with a cadaver renal transplant, CAN, and non-ferropenic anemia. The aim of the study was to determine the safety and efficacy of treatment with rEpo to target hematocrit (HCT) values around 35% and/or hemoglobin (Hb) levels of 11 g/dL.

RESULTS

Twenty-four patients were included: 71% males and 29% females aged 49.5 +/- 14 years. At last follow-up, 48% did not show anemia-related symptoms, and 19% experienced adverse events possibly or probably related to rEpo. In 86% of cases, anemia was corrected and in 71%, graft survival was conserved. Patients whose anemia was not corrected had poor initial renal function (sCr 5 +/- 1 mg/dL vs sCr 3.2 +/- 1 mg/dL, P = .028). Patients with graft survival showed correction of anemia (P = .001) on a relatively low dose of rEpo and without a significant increase in blood pressure.

CONCLUSIONS

All patients who had graft survival and only half of those who lost their graft showed a correction of anemia. The rEpo treatment neither accelerated nor decelerated renal failure. The difference between patients in whom anemia was corrected, or not, did not depend upon the previous level of HCT/Hb, but upon worse renal function. Thus, rEpo in patients with CAN is safe and effective, so administration should be initiated early to avoid adverse events deriving from anemia.

Epidemiology and Outcomes of Multiple Antibiotic–Resistant Bacterial Infection in Renal Transplantation

BACKGROUND

Mutiresistant bacterial infections are an emerging problem in the nosocomial setting. Our objectives were to describe the incidence, outcome, and risk factors for acquisition of multiresistant bacteria among renal transplant recipients.

METHODS

We prospectively followed patients undergoing kidney transplantation over a 3-year period. We collected demographic features, underlying chronic diseases, and main transplant characteristics and complications. Multiple antibiotic resistance was defined for the most important bacteria: Enteric gram-negative bacilli resistant to betalactamics, cephalosporins, and quinolones; Staphylococcus aureus resistant to methicillin, cotrimoxazole, and clindamcin; Enterococcus spp resistant to ampicillin and quinolones; nonfermentator bacilli resistant to all antibiotics except aminoglycosides and collistin.

RESULTS

Overall, 416 patients included 65 double transplants (62 kidney-pancreas and three kidney-liver) of mean age 48.5 years, and 57% men. Infection with multiresistant bacteria was observed in 58 patients (14%). Most frequent multiresistant bacteria were: Escherichia coli (n = 33), Klebsiella spp (n = 15), Citrobacter spp (n = 8), Enterobacter spp (n = 5), Morganella morganii (n = 2), Pseudomonas aeruginosa (n = 16), Acinetobacter baumanii (n = 2), Enterococcus spp (n = 9) and methicillin-resistant S. aureus (MRSA, n = 2). Age greater than 50 years, hepatitis C virus infection, double kidney-pancreas transplantation, requirement for posttransplant hemodialysis, surgical reoperation, and requirement for nephrostomy were independent variables associated with multiresistant bacterial infection. Most used antibiotics for treatment were: carbapenems (65%), amikacin (12%), linezolid, piperacillin-tazobactam, vancomycin, collistin, and fosfomycin. Infection with multiresistant bacteria was associated with a worse prognosis (graft loss or death, 19% vs 8%, P = .009).

CONCLUSIONS

The incidence of infection with multiresistant bacteria in our renal transplant cohort was high, being most frequently cephalosporin-resistant enteric gram-negative bacilli and multiresistant P aeruginosa. Methicillin-resistant S. aureus incidence was low. Infection with multiresistant bacteria conferred a worse prognosis.

Infection-Related Mortality in a Large Cohort of Renal Transplant Recipients

INTRODUCTION

Infections represent a major cause of morbidity and mortality among renal transplant recipients. Our aim was to analyze the incidence and etiology of infection-related mortality among a large cohort of renal transplant recipients.

METHODS

From 1995 to 2004, we collected all causes of mortality among patients receiving a renal transplantation. The date of transplant, the last follow-up/death, type of transplant, age, and cause of death were tabulated into a database. The incidence rate of mortality was calculated in events per 10,000 transplant months.

RESULTS

Among the 1218 renal transplants performed in the study period the causes of mortality were: cardiovascular, 65 (38%); infection, 49 (29%); cancer, 21 (12%); other causes, 18 (10.5%); and unknown, 18 (10.5%). Infection-related mortality were: sepsis = 17 (35%), bacterial pneumonia = 9 (18%), abdominal bacterial infection = 2 (4%), invasive viral infection = 12 (24%), and invasive fungal infection = 9 (18%). There were no differences in the global causes of mortality according to the year of transplantation. The incidence rate of infection-related mortality was higher among aged patients and similar to cardiovascular-related mortality. Comparing the periods 1995 to 1999 with 2000 to 2004, bacterial infection-related mortality remained stable (57% vs 57%), while viral infection-related mortality decreased (31% vs 7%) and fungal infection-related mortality increased (11% vs 36%; P = .06).

CONCLUSIONS

In the last decade, infection-related mortality among renal transplant recipients has not decreased. Although better control of invasive viral infections has been achieved, bacterial and fungal invasive infections remain important causes of mortality in this population.

Impact of Carotid Atherosclerosis as Assessed by B-Mode Ultrasonography on the Evolution of Kidney Transplantation

Carotid arteriosclerosis is a marker of cardiovascular risk in the general population. Cardiovascular disease is highly prevalent in kidney transplant recipients. This study analyzed the impact of arteriosclerotic carotid lesions on the evolution of renal transplant recipients.

METHODS

This prospective study was performed in 70 patients with renal transplantations (mean age 52 +/- 12 years; 67% men (n = 47). High-resolution B-mode ultrasonography (7.5 MHz) of both carotid arteries was performed at baseline to assess carotid caliber, mean and maximum intima-media thickness (IMT), presence of arteriosclerotic plaques (number and maximum height), and percentage stenosis. We analyzed the impact of carotid arteriosclerosis and various donor-recipient clinical covariables on long-term patient and graft survival.

RESULTS

Mean follow-up was 9.7 +/- 2.5 years (2-14). Atheroma plaques were detected in 74% of patients (n = 52). The mean number of plaques was 3.96 +/- 2.88 and maximum plaque height was 2.49 +/- 0.97 mm. IMT was 0.71 +/- 0.21 mm (0.4-1.5) with 27% of patients (n = 19) having an IMT value greater than 0.8 mm. Sonographic signs of occlusion were evident in 13% (n = 9) and the mean occlusion was 33 +/- 11% (range 20%-45%). The presence of plaques was significantly associated with age (P = .002), hypertension and diabetes (P = .016), and hypercholesterolemia (P = .01). There was an association between age and arterial wall thickness (P = .042). Acute rejection was an independent risk factor for graft loss (OR 8.14, P = .003). The multivariate study identified carotid wall thickness as an independent risk factor for patient death (OR 12.7, P = .017).

CONCLUSION

Carotid arteriosclerosis is highly prevalent among renal transplant recipients. Carotid lesions were an independent risk factor for long-term patient death. High-resolution ultrasound imaging of the carotid arteries was a useful, noninvasive diagnostic technique for accurate assessment of cardiovascular risk in renal transplant recipients.

Quality of Life in Renal Transplant Recipients Following Conversion From Mycophenolate Mofetil to Enteric-Coated Mycophenolate Sodium

INTRODUCTION

Tolerance to immunosuppresant treatment has considerable impact on adherence to therapy and on the outcome of renal transplantation. Recent data indicate better gastrointestinal tolerance to enteric-coated mycophenolate sodium (EC-MPS) than to the classic mycophenolate mofetil (MMF) formulation.

AIM

This study assessed the effect of conversion therapy from MMF to EC-MPS on gastrointestinal tolerance and quality of life in renal transplant recipients.

METHODS

This open observational study analyzed the outcomes of conversion from MMF to EC-MPS among renal transplant patients with gastrointestinal complaints. At baseline (B) and at 8 weeks postconversion patients were assessed by the Gastrointestinal Quality of Life Index (GIQLI) questionnaire as well as by clinical evaluation (acute rejection, infection) and analytical determinations.

RESULTS

We analyzed 18 recipients of cadaveric renal transplants of mean age of 54 +/- 9 years including 61% men and one retransplant. Our patients had stable renal function with mean creatinine of 1.9 +/- 0.7 mg/dL. Baseline treatment included cyclosporine-MMF-prednisone (33%) or FK-MMF-prednisone (66%). Bioequivalent conversion was carried out at 50 +/- 29 months posttransplantation. Conversion to EC-MPS resulted in an improvement in overall quality of life (total score: baseline 106.61 vs 8 weeks 116.89; P < .01). Improvements were observed in the following GIQLI subscales: gastrointestinal symptoms (3.12 vs 3.48, P < .001), physical function (2.54 vs 2.76, P = .003), medical treatment (2.17 vs 2.50, P = .031), and emotion (3.08 vs 3.39, P = .001). No changes were observed in the social function subscale. The hemogram and renal function remained stable; there were no episodes of rejection or infection.

CONCLUSION

Conversion from MMF to an EC-MPS formulation was associated with improvements in gastrointestinal complaints and quality of life among renal transplant recipients.

Sirolimus Monotherapy as Maintenance Immunosuppression: Single-Center Experience in 50 Kidney Transplant Patients

INTRODUCTION

Chronic allograft nephropathy, cardiovascular mortality, and posttransplant malignancy are complications of conventional immunosuppression after kidney transplantation. We reported the feasibility of maintenance monotherapy with sirolimus (SRL) in a pilot experience. The aim was to study safety and feasibility of SRL maintenance monotherapy in 50 kidney transplant patients.

METHODS

All patients from our center with at least 6 months follow-up on SRL monotherapy were included. During the first month after start of SRL monotherapy, follow-up visits were performed weekly, then each month for the following 2 months. Each follow-up visit included a physical exam and laboratory screening.

RESULTS

Mean follow-up on SRL monotherapy was 34.7 +/- 14.9 months. The time between transplantation until start of monotherapy was 7.7 +/- 3.3 years. No rejections occurred. During follow-up, two patients died of cardiovascular disease (already diagnosed before monotherapy); one, of previously diagnosed posttransplant malignancy and one, of hepatitis C-related liver failure. Glomerular filtration rate (GFR) was 53 mL/min x 1.73 m2 at start of monotherapy and 50 mL/min x 1.73 m2 after 4 years. Proteinuria was 632 +/- 562 mg/24 hours at 4 years. During the follow-up, no significant changes in the lipid profile, glycemia, or hemoglobin occurred.

CONCLUSIONS

Sirolimus monotherapy is safe in a selected group of immunological low-risk patients without increasing the risk of rejection.

Results of an international, randomized trial comparing glucose metabolism disorders and outcome with cyclosporine versus tacrolimus

DIRECT (Diabetes Incidence after Renal Transplantation: Neoral C(2) Monitoring Versus Tacrolimus) was a 6-month, open-label, randomized, multicenter study which used American Diabetes Association/World Health Organization criteria to define glucose abnormalities. De novo renal transplant patients were randomized to cyclosporine microemulsion (CsA-ME, using C(2) monitoring) or tacrolimus, with mycophenolic acid, steroids and basiliximab. The intent-to-treat population comprised 682 patients (336 CsA-ME, 346 tacrolimus): 567 were nondiabetic at baseline. Demographics, diabetes risk factors and steroid doses were similar between treatment groups. The primary safety endpoint, new-onset diabetes after transplant (NODAT) or impaired fasting glucose (IFG) at 6 months, occurred in 73 CsA-ME patients (26.0%) and 96 tacrolimus patients (33.6%, p = 0.046). The primary efficacy endpoint, biopsy-proven acute rejection, graft loss or death at 6 months, occurred in 43 CsA-ME patients (12.8%) and 34 tacrolimus patients (9.8%, p = 0.211). Mean glomerular filtration rate (Cockcroft-Gault) was 63.6 +/- 20.7 mL/min/1.73 m(2) in the CsA-ME cohort and 65.9 +/- 23.1 mL/min/1.73 m(2) with tacrolimus (p = 0.285); mean serum creatinine was 139 +/- 58 and 133 +/- 57 mumol/L, respectively (p = 0.005). Blood pressure was similar between treatment groups at month 6, but total cholesterol, LDL-cholesterol and triglyceride levels were significantly higher with CsA than with tacrolimus (total cholesterol:HDL remained unchanged). The profile and incidence of adverse events were similar between treatments. The incidence of NODAT or IFG at 6 months post-transplant is significantly lower with CsA-ME than with tacrolimus without a significant difference in short-term outcome.

Complete Regression of Cutaneous B-Cell Lymphoma in a Renal Transplant Patient After Conversion From Cyclosporin to Sirolimus

Posttransplant lymphoproliferative disease remains a serious morbidity. Herein we have reported a case of complete regression of a biopsy-proven B-cell lymphoma that occurred in the posttransplant period. A 48-year-old man received a living donor renal transplant for end-stage renal disease due to undetermined etiology. His initial immunosuppression consisted of corticosteroid, mycophenolate mofetil, and cyclosporin. The patient developed severe pneumonia within the first 2 months after transplantation due to Acineotobacter, fungus, and cytomegalovirus infections. He experienced a complete recovery and was discharged for regional follow-up. Four months after discharge, he was referred again because of presence of two nodules on his trunk. A biopsy of the nodules revealed B-cell lymphoma. Cyclosporin was stopped and he was converted to sirolimus. The lesions regressed progressively and completely within 7 weeks. The patient remains well without clinical relapses at 19 months after conversion. Renal functions remained stable. We postulated that the antincoplastic properties of sirolimus may have played an active part in the positive outcome.

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

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

[Parathyroid carcinoma associated to secondary hyperparathyroidism in hemodialyzed patients. Two cases reports]

Parathyroid carcinoma (PC) is an infrequent disease with a subtle initial presentation and a variable course, necessitating a high index of suspicion to make the correct diagnosis. In chronic failure patients on haemodialysis it becomes even more difficult to suspect this entity since the high prevalence of secondary hyperparathyroidism(SHP). Two patients with PC out of a series of 160 patients with moderate-to-severe SHP submitted for parathyroidectomy are reported. Their clinical features are compared with those of the twenty-two cases previously reported in the literature with a discussion of this pathology. Patients with PC showed higher blood levels of iPTH, total calcium, phosphate and total alkaline phosphatase than the SHP population. The final diagnosis of PC was made after histological study revealing capsular or blood vessel invasion.

Utilidad de la gammagrafía con plaquetas marcadas con 111In-oxina en el manejo del síndrome febril en pacientes en diálisis portadores de injerto renal no funcionante

AIM

To evaluate the usefulness of 111In-oxine-labelled platelet scan in the therapeutic management of prolonged febrile syndrome in dialysis patients with a non-functional renal allograft.

MATERIAL AND METHODS

One hundred and fifty-eight patients (94 men, 64 women; mean age 44 +/- 9 years) were studied. Duration of fever was 42 days (range 7-112). A total of 68 % of the patients (107/158) were on low doses of corticosteroids (<10 mg/day). Platelet scans were performed 48 hours after reinjection of 111In-ixone-labelled platelets. A platelet uptake index (PUI) was calculated by dividing the cpm/pixel in the allograft by the cpm/pixel in a mirror background. A PUI > or = 1.5 was considered as threshold for immunological fever. The final diagnosis of immunological fever was established when it disappeared after transplantectomy, embolization or high doses of corticosteroid therapy. Fever of non-immunological origin was established when it disappeared after antibiotic therapy.

RESULTS

In 102/158 patients the fever was considered of immunological origin. In 56/158 patients the fever was considered of non immunological origin. Sensitivity and the specificity of the platelet scan was 80 % and 100 %, respectively. All those patients considered as having fever of immunological origin who had PUI <1.5 had been using corticosteroids during platelet scan.

CONCLUSION

111In-labelled platelet scintigraphy is a useful technique in the therapeutic management of prolonged febrile syndrome in dialysis patients with non-functional renal allograft. The use of corticosteroids can reduce the sensitivity of 111In- labelled platelet scan.

Effect of apolipoprotein B polymorphism in kidney transplantation

INTRODUCTION

In kidney transplant recipients, dyslipidemia is a cardiovascular risk factor that also contributes to the development and progression of chronic allograft nephropathy. Apolipoprotein B (ApoB), present in low-density lipoproteins (LDL), is an important protein component of chylomicrons and very-low-density lipoproteins (VLDL). The del allele of the ApoB signal peptide polymorphism has been associated with elevated levels of total and LDL cholesterol and greater risk of coronary disease.

OBJECTIVE

The objective of this study was to assess the influence of ApoB polymorphism on allograft and patient survival among kidney transplant recipients.

METHODS

In this study, we analyzed 516 renal transplant recipients (38% were women, 62% were men), aged 46 +/- 15 years, with a minimum follow-up of 12 months (mean, 1854 +/- 806 days). The ApoB signal peptide was analyzed (insertion/deletion) using polymerase chain reaction (PCR) using genomic DNA. Clinical donor-recipient variables were assessed using a Cox multivariate model.

RESULTS

Polymorphism distribution was as follows: insertion/insertion (ins/ins) 51%, insertion/deletion (ins/del) 39%, and deletion/deletion (del/del) 9%, with no differences between the genders. Cholesterol levels at 12 months showed no differences between the ins/ins (217 +/- 46), ins/del (228 +/- 50), and del/del (227 +/- 54) groups. Presence of the ApoB signal peptide del/del or ins/del genotype was independently associated with lower patient survival in the group of men younger than 60 years (P < .05). Among the total deaths, cardiovascular causes predominated in the ins/del and del/del groups (50%) as compared with the ins/ins group (33%) (P < .01).

CONCLUSIONS

ApoB genetic polymorphism (del allele) seems to have an adverse effect on the long-term survival of kidney transplant recipients.

Kidney-specific proteins in patients receiving aprotinin at high- and low-dose regimens during coronary artery bypass graft with cardiopulmonary bypass

BACKGROUND AND OBJECTIVE

The aim was to determine whether the administration of aprotinin can cause deleterious effects on renal function in cardiac surgery with cardiopulmonary bypass (CPB).

METHODS

Sixty consecutive patients with normal preoperative renal function undergoing elective coronary artery bypass surgery with CPB using the same anaesthetic; CPB and surgical protocols were randomized into three groups. Patients received placebo (Group 1), low-dose aprotinin (Group 2) or high-dose aprotinin (Group 3). Renal parameters measured were plasma creatinine, alpha1-microglobulin and beta-glucosaminidase (beta-NAG) excretion. Measurements were performed before surgery, during CPB and 24 and 72 h, and 7 and 40 days postoperatively.

RESULTS

In the three groups, alpha1-microglobulin and beta-NAG excretions significantly increased during CPB, at 24 and 72 h, and 7 days postoperatively (P < 0.05) and had returned to preoperative levels at postoperative day 40. Plasma creatinine levels were within normal values at times recorded. In Groups 2 and 3, alpha1-microglobulin excretion during CPB was significantly higher than in Group 1 (P < 0.001), and 24h after surgery it still remained significantly higher in Group 3 compared to Groups 1 and 2 (P < 0.05).

CONCLUSIONS

Aprotinin caused a significant increase in alpha1-microglobulin excretion but not in beta-NAG excretion during CPB, which may be interpreted as a greater renal tubular overload without tubular damage. This effect persisted for 24 h after surgery when high-dose aprotinin doses had been administered. Creatinine plasma levels were not sensitive to detect these prolonged renal effects in our study.

Efficacy of Conversion to Sirolimus in Posttransplantation Kaposi’s Sarcoma

The increased incidence of Kaposi's sarcoma (KS) in organ transplantation has been related to the KS herpes virus and the permissive effect of immunosuppressive therapy. We postulated that conversion to SRL in renal recipients with KS favored regression of KS lesions without increasing the risk of graft rejection.

METHODS

In this study we performed a retrospective chart review of 7 caucasian renal transplant recipients affected by KS to determine demographic data, etiology of ESRD, immunologic risk factors, immunosuppressive treatment, KS disease follow-up, and renal function before and after SRL conversion.

RESULTS

All seven patients were under calcineurin inhibitor treatment at the onset of KS which was limited to the skin, without regression despite attempts to minimize immunosuppression. After conversion to SRL, six patients showed progressive regression of KS lesions, with only hyperpigmented atrophic cutaneous lesions remaining after a mean time of 8.1 months (2-18 months). The seventh patient has completed 9 months follow-up with a near complete regression of KS lesions. One patient returned to hemodialysis after 13 months following irreversible acute renal failure not directly related to SRL conversion; in the other six, renal function was stable. The mean serum creatinine was 1.87 +/- 0.64 versus 1.74 +/- 0.68 mg/dL, pre-conversion versus the end of follow up, respectively. Mean SRL blood level was 9.2 +/- 2.0 ng/mL.

CONCLUSION

After SRL conversion, patients with KS showed progressive regression without an increased risk of acute rejection. SRL offers a promising approach to the management of posttransplantation KS and probably other malignancies in organ transplant recipients.