[Acute renal failure of the donor in encephalic death: A real contraindication to kidney transplantation?]

INTRODUCTION

The shortage of kidney transplants encourages the expansion of the limits of eligibility criteria for donation. Many donors who are brain dead display acute renal failure at the time of death; is this a real contraindication to harvesting? The aim of this study was to assess kidney graft survival from donors after brain death with confirmed acute renal failure, with or without anuria previous donation.

MATERIALS AND METHODS

All of the transplants performed in two university hospitals between 2010 and 2017 were analyzed retrospectively. All patients who underwent single kidney transplant from a brain-dead donor with acute renal failure (ARF) were included in this study. ARI was defined here by a decrease over 50 % of glomerular filtration rate (GFR) to a threshold below 45mL/min/1.73 m² at the time of kidney procurement. Kidney graft survival, incidence of delayed graft function (DGF) and the GFR at 12 months were analyzed. Analysis of kidney transplant survival based on pre-implantation biopsies was additionally done.

RESULTS

One hundred and sixty four patients were transplanted with a kidney from donor with ARF during the selected period. At the admission in ICU the average GFR was 67,7±19mL/min/1,73m². At the time of donation, the average age of donors was 56.4±17.7 years, the GFR was 33.7±8.0mL/min/1.73 m² 16 % of donors were anuric. Cold ischemia time (CIT) was 16.8±5.0hours. The average age of recipients was 55.6±14.1 years. 81 % of the cases were primary transplants. Graft function took place within 7.8±9.4 days after transplantation. There were two non-primary functions (PNF). One hundred and fifty two patients (93 %) had a functional graft at 12 months. The mean GFR at 12 months was 46.8±20.1mL/min/1.73 m² and 122 patients (73 %) had a GFR greater than 30mL/min/1.73 m². Seventy-one percent of preimplantation biopsies revealed acute tubular necrosis (ATU); no cortical necrosis was observed. Survival of theses grafts was 85 %, comparable to the total population of study (P=0,21) CONCLUSION: The acute renal failure of the brain-dead donor should not alone be systematically a contraindication to harvesting and kidney transplantation.

Management of vascular and nonvascular complications following pancreas transplantation with interventional radiology

Pancreas transplantation exposes to high rates of complications, either vascular (thrombosis, stenosis, pseudoaneurysm, arteriovenous fistula) or nonvascular (fluid collection, graft rejection). With advances in percutaneous and endovascular techniques, interventional radiologists are increasingly involved in the management of these complications. In this article, we review the anatomical considerations relevant to pancreas transplantation, the techniques used for image-guided interventions for vascular and nonvascular complications, and the expected outcomes of these interventions.

Hypothermic pulsatile perfusion of human pancreas: Preliminary technical feasibility study based on histology

BACKGROUND

There are currently two approaches to hypothermic preservation for most solid organs: static or dynamic. Cold storage is the main method used for static storage (SS), while hypothermic pulsatile perfusion (HPP) and other machine perfusion-based methods, such as normothermic machine perfusion and oxygen persufflation, are the methods used for dynamic preservation. HPP is currently approved for kidney transplantation.

METHODS

We evaluated, for the first time, the feasibility of HPP on 11 human pancreases contraindicated for clinical transplantation because of advanced age and/or history of severe alcoholism and/or abnormal laboratory tests. Two pancreases were used as SS controls, pancreas splitting was performed on 2 other pancreases for SS and HPP and 7 pancreases were tested for HPP. HPP preservation lasted 24 h at 25 mmHg. Resistance index was continuously monitored and pancreas and duodenum histology was evaluated every 6 h.

RESULTS

The main finding was the complete absence of edema of the pancreas and duodenum at all time-points during HPP. Insulin, glucagon and somatostatin staining was normal. Resistance index decreased during the first 12 h and remained stable thereafter.

CONCLUSION

24 h hypothermic pulsatile perfusion of marginal human pancreas-duodenum organs was feasible with no deleterious parenchymal effect. These observations encourage us to further develop this technique and evaluate the safety of HPP after clinical transplantation.

Liraglutide in whole-pancreas transplant patients with impaired glucose homoeostasis: A case series

Hyperglycaemia may develop after whole-pancreas transplantation (PTX) in patients with type 1 diabetes mellitus (T1DM), but the efficacy and tolerability of GLP-1 receptor agonists have not been assessed in this population. This report is a 6-month prospective follow-up of six T1DM recipients of PTX (mean time after PTX: 68.8 ± 45.7 months), all of whom had an HbA1c>6.5% (48 mmol/mol) [mean: 7.1% (54 mmol/mol)] after initiation of liraglutide alone at 0.6 mg once daily titrated to 1.2mg once daily at week 1. Gastrointestinal disorders were reported in three of the six patients, with discontinuation of liraglutide in only one patient. HbA1c improved in the five remaining patients, with a median decrease of 0.8% (0.0-2.7%) at 6 months, and the median decrease in body weight was 2.0 kg. Immunosuppressive treatments remained unchanged with liraglutide. Thus, liraglutide appears to be an effective and well-tolerated option in PTX patients with impaired glucose homoeostasis, regardless of the cause.

Early corticosteroid avoidance in kidney transplant recipients receiving ATG-F induction: 5-year actual results of a prospective and randomized study

One hundred ninety-seven patients received anti-T-lymphocyte globulins Fresenius, mycophenolate mofetil and delayed cyclosporine, and were randomized to ≥6-month corticosteroids (+CS; n=99) or no CS (-CS; n=98). One- and five-year actual graft survival (censored for death) was 93.2% and 86.4% in the +CS group versus 94.9% and 89.8% in the -CS group (5-year follow-up, p=0.487). Freedom from clinical rejection was 86.9% and 81.8% versus 74.5% and 74.5% (p=0.144), respectively, at 1 and 5 years; 5-year freedom from biopsy-proven rejection was 88.9% versus 83.7% (p=0.227). More late first rejections occurred in the +CS group. Significantly lower 5-year graft survival in patients experiencing rejection was observed for +CS (55.6% vs. 92.0%; p=0.005) with 8/18 versus 2/25 graft losses. Renal function at 5 years was stable and comparable (median serum creatinine, 159 vs. 145 µmol/L; creatinine clearance, 53.5 vs. 56.6 mL/min). More +CS patients developed diabetes, dyslipidemia and malignancies. Rejections in -CS patients occurred early after transplantation and did not impair long-term renal function. In patients receiving CS, rejections occurred later and with a higher risk for subsequent graft failure. A similar and not inferior 5-year efficacy profile and a reduced morbidity were observed in CS-free patients compared to patients who received CS for at least 6 months.

Posttransplant donor-specific anti-HLA antibodies negatively impact pancreas transplantation outcome

During a 9-year follow-up, 167 consecutive pancreas transplant recipients (152 simultaneous pancreas-kidney [SPK]) were followed for the detection of posttransplant anti-HLA antibodies. Forty patients (24%) developed anti-HLA antibodies, 26 (65%) had donor-specific antibodies (DSA; 61% anticlass 2) and 14 (35%) non-DSA (78.6% anticlass 1). More rejection episodes were observed in patients with positive anti-HLA antibodies than in patients without antibodies (42.5% vs. 11%; p = 0.001), with the highest incidence observed in DSA patients (53.8%). More severe rejections (according to rescue therapy) were observed in DSA patients compared to non-DSA (p < 0.05) or to negative patients (p < 0.001). Contrasting with the kidney, pancreas graft survival did not differ between patients with or without anti-HLA antibodies. On the contrary, pancreas and kidney survivals were significantly lower in DSA positive patients (75% for both organs) as compared to non-DSA positive patients (100% for pancreas and 92% for kidney) or to HLA-negative patients (91% for pancreas and 89% for kidney). Nontechnical pancreas and kidney graft failures were significantly higher in positive than in negative anti-HLA patients (32.5% vs. 11%; p < 0.01). Occurrence of posttransplant DSA was an independent risk factor for both pancreas and kidney survival (HR 3.2; p = 0.039) in diabetic transplant recipients.

Guidelines for the diagnosis of antibody-mediated rejection in pancreas allografts-updated Banff grading schema

The first Banff proposal for the diagnosis of pancreas rejection (Am J Transplant 2008; 8: 237) dealt primarily with the diagnosis of acute T-cell-mediated rejection (ACMR), while only tentatively addressing issues pertaining to antibody-mediated rejection (AMR). This document presents comprehensive guidelines for the diagnosis of AMR, first proposed at the 10th Banff Conference on Allograft Pathology and refined by a broad-based multidisciplinary panel. Pancreatic AMR is best identified by a combination of serological and immunohistopathological findings consisting of (i) identification of circulating donor-specific antibodies, and histopathological data including (ii) morphological evidence of microvascular tissue injury and (iii) C4d staining in interacinar capillaries. Acute AMR is diagnosed conclusively if these three elements are present, whereas a diagnosis of suspicious for AMR is rendered if only two elements are identified. The identification of only one diagnostic element is not sufficient for the diagnosis of AMR but should prompt heightened clinical vigilance. AMR and ACMR may coexist, and should be recognized and graded independently. This proposal is based on our current knowledge of the pathogenesis of pancreas rejection and currently available tools for diagnosis. A systematized clinicopathological approach to AMR is essential for the development and assessment of much needed therapeutic interventions.

Banff schema for grading pancreas allograft rejection: working proposal by a multi-disciplinary international consensus panel

Accurate diagnosis and grading of rejection and other pathological processes are of paramount importance to guide therapeutic interventions in patients with pancreas allograft dysfunction. A multi-disciplinary panel of pathologists, surgeons and nephrologists was convened for the purpose of developing a consensus document delineating the histopathological features for diagnosis and grading of rejection in pancreas transplant biopsies. Based on the available published data and the collective experience, criteria for the diagnosis of acute cell-mediated allograft rejection (ACMR) were established. Three severity grades (I/mild, II/moderate and III/severe) were defined based on lesions known to be more or less responsive to treatment and associated with better- or worse-graft outcomes, respectively. The features of chronic rejection/graft sclerosis were reassessed, and three histological stages were established. Tentative criteria for the diagnosis of antibody-mediated rejection were also characterized, in anticipation of future studies that ought to provide more information on this process. Criteria for needle core biopsy adequacy and guidelines for pathology reporting were also defined. The availability of a simple, reproducible, clinically relevant and internationally accepted schema for grading rejection should improve the level of diagnostic accuracy and facilitate communication between all parties involved in the care of pancreas transplant recipients.

[Dialysis-associated spondyloarthropathy. Case report and literature review]

Hemodialysis has considerably prolonged the life of patients suffering from terminal renal failure. However, long-term hemodialysis leads to new bone complications and spinal disorders such as destructive spondyloarthropathy (DSA). At the present time DSA is reported in 8% to 18% of the dialysed patients. Diagnosis is based on severe narrowing of the intervertebral disk, erosions and geodes of the adjacent vertebral plates simulating infectious spondylitis. Lesions progressively involve posterior joints and may lead to severe destruction of the spine. The pathogenesis of this syndrome is still unknown. Several factors have been implicated, including microcrystal deposition, amyloidosis, inflammatory and foreign body reactions and suggest that the pathogenesis of erosive spondyloarthropathies of hemodialysed patients is multifactorial. Spinal instability inducing myelopathy and radiculopathy were observed in 8% of the cases. Treatment must be accorded to the natural disease course and to the quality of the bone. We report the case of a chronic dialysed patient with destructive spondyloarthropathy involving the cervical and thoracic spine. Pathogenesis, radiological datas and therapeutic approach are discussed.

Prevention of acute rejection with antithymocyte globulin, avoiding corticosteroids, and delaying cyclosporin after renal transplantation

BACKGROUND

Despite their well-known side-effects, corticosteroids (Cs) are currently used after kidney transplantation. Avoidance of Cs may improve patient quality of life and eventual long-term survival. We report on a regimen using antithymocyte globulin (ATG) and mycophenolate mofetil (MMF) for induction, and cyclosporin (CsA) plus MMF for maintenance treatment of recipients of primary kidney transplantation.

METHODS

We studied 11 consecutive, non-sensitized renal transplant patients (nine cadaver and two living donors). Initial immunosuppression consisted of ATG (1.5 mg/kg/day, i.v.) given for 10 days and MMF (1.0 g/b.i.d.). CsA (8 mg/kg, in two divided doses) was started on post-operative day 11. Cs were only allowed in the case of MMF discontinuation, for the treatment of acute rejection, and in the event of recurrence of the primary glomerulonephritis.

RESULTS

All patients completed the entire 10-day ATG course. Main side-effects included fever (>38 degrees C) and serum sickness, observed in 73 and 27% of the patients respectively. The incidence of acute rejection was 27% (three of 11 patients). In two patients with acute rejection, serum sickness was concomitantly diagnosed and renal histology was partially compatible with immune-complex disease. The remaining patient had two episodes of low-grade rejection. All rejection episodes were rapidly reversed. Two patients (18%) were treated with ganciclovir for cytomegalovirus (CMV) infection. Two patients (18%) are currently receiving Cs for recurrence of the native glomerulonephritis and two rejection episodes respectively. All patients are currently alive with functioning kidneys (average follow-up of 8.4 months; average creatinine level of 128 micromol/l).

CONCLUSION

This pilot study suggests that ATG induction in combination with MMF and delayed introduction of CsA, in the absence of Cs, is not well tolerated in recipients of kidney transplants. An earlier introduction of calcineurin inhibitors and/or a shorter course of ATG may reduce the incidence of fever and serum sickness secondary to ATG.

Clinical relevance of direct quantification of pp65 antigenemia using flow cytometry in solid organ and stem cell transplant recipients

A total of 1,305 blood samples from 85 solid organ transplant (SOT) recipients and 25 stem cell transplant (SCT) recipients at risk for cytomegalovirus (CMV) infection were prospectively collected and tested using the shell vial assay (SVA) and a leukocytic qualitative PCR (q-PCR). Of these, 462 specimens were further tested by direct quantification of CMV antigenemia by flow cytometry (FC-Ag), 125 were tested with a quantitative competitive PCR, and 200 were tested for pp65 antigenemia using the slide method (S-Ag). Laboratory data were statistically analyzed according to the presence of CMV-related symptoms. In SOT and SCT recipients, active CMV infection occurred in 63.5 and 36%, respectively, and CMV disease occurred in 53 and 24%, respectively. FC-Ag results correlated better with q-PCR and S-Ag than with SVA. The first test found to be positive during follow-up was FC-Ag in 73% of cases. In SOT recipients, FC-Ag showed the highest sensitivity and negative predictive value for the diagnosis of any grade of CMV disease. For FC-Ag, the threshold beyond which CMV disease was highly probable seemed to lie at 0.20% positive polymorphonuclear leukocytes. FC-Ag appears to be a useful test for the early detection of CMV infection and the prediction of CMV disease.

Evaluation of clinical guidelines for the management of end-stage renal disease in europe: the EU BIOMED 1 study

BACKGROUND

There are wide national and international variations in the management of patients with end-stage renal disease (ESRD). The aim of this study was to develop, harmonize, implement, and evaluate consensus-based clinical guidelines for the management of renal anaemia and renal bone disease in patients with ESRD, and for the prevention and management of cytomegalovirus disease in renal transplant recipients across six renal centres in Europe.

METHODS

The trial was a prospective, multicentre, randomized balanced incomplete block design. Nephrologists from the six European renal units were randomized to develop and implement guidelines for two out of the three conditions and to act as a control for the third condition. Data were collected pre- (1 year) and post- (9 months) intervention on aspects of patient monitoring, management, and outcome.

RESULTS

Eight hundred and twenty-nine dialysis patients from the six European dialysis centres were included in the study. Multivariate analysis (adjusting for case-mix and secular trends) showed a significant increase in the number of monitoring events in the guideline group compared with control group (6%, 95% CI, 1-11%). There was no concomitant increase in either appropriate management or the number of favourable patient outcomes.

CONCLUSIONS

In the first European collaboration on renal guidelines, the introduction of the guidelines improved the monitoring of the patients, but did not improve patient management or outcome. This study suggests the potential for creating clinical guidelines with the aim of standardizing treatment protocols across international boundaries, and improving the quality of the medical care provided.

Low incidence of kidney rejection after simultaneous kidney-pancreas transplantation after antithymocyte globulin induction and in the absence of corticosteroids: results of a prospective pilot study in 28 consecutive cases

BACKGROUND

Recipients of simultaneous kidney-pancreas transplantation receive a combination of polyclonal antithymocyte globulin (ATG), cyclosporin or tacrolimus, mycophenolate mofetil (MMF) and corticosteroids (Cs). To avoid the side effects and adverse events associated with Cs, we investigated a new immunosuppressive regimen without Cs after simultaneous kidney-pancreas transplantation.

METHODS

A total of 28 consecutive patients who underwent simultaneous kidney-pancreas transplantation were included in this study. All patients received ATG, cyclosporin, and MMF.

RESULTS

All patients but one tolerated the ATG course well. MMF was definitively discontinued in three patients because of leukopenia. Cytomegalovirus infection was diagnosed in eight patients (28.5%). Only two patients (7%) required an antirejection treatment. Patient, kidney, and pancreas survival is currently 96.4, 96.4, and 75%, respectively.

CONCLUSIONS

The combination of ATG, cyclosporin, and MMF, without Cs, was well tolerated. The unexpectedly low (7%) incidence of acute kidney rejection observed suggests that Cs may partially interfere with the immunosuppressive effect of ATG.

Use of reverse transcription polymerase chain reaction with colorimetric plate hybridization to detect a cytomegalovirus late spliced mRNA in polymorphonuclear leukocytes from renal transplant patients

Human cytomegalovirus replication was evaluated in polymorphonuclear leukocytes from ten renal transplant recipients. Three new reverse transcription polymerase chain reactions with plate hybridization suitable for automation were developed for the detection of immediate-early spliced UL123 mRNA, early-late pp65 mRNA, and late spliced UL22 mRNA. The presence of UL22mRNA was found to be significantly associated with the occurrence of cytomegalovirus (CMV) disease.

Randomized comparison of triple therapy and antithymocyte globulin induction treatment after simultaneous pancreas-kidney transplantation

BACKGROUND

The incidence of acute rejection is considered to be higher after simultaneous pancreas-kidney (SPK) transplantation as compared to renal transplant alone. Therefore, the majority of SPK transplant recipients commonly receive a combination of cyclosporine (CsA) or tracolimus, and azathioprine or mycophenolic mofetyl, corticosteroids and/or antilymphocyte preparations. This study was designed to compare two immunosuppressive protocols for the prevention of acute rejection in patients undergoing SPK transplantation. The primary end-point was the incidence of acute rejection during the first 12 months after transplantation

METHODS

Fifty patients with type-I insulin-dependent diabetes and chronic renal failure were randomized to receive a triple drug immunosuppressive regimen including CsA, azathioprine and corticosteroids (N = 25), or the quadruple sequential combination of rabbit antithymocyte globulin (ATG) given for 10 days, azathioprine, corticosteroids and delayed CsA (N = 25). Maintenance immunosuppression (CsA and azathioprine, without corticosteroids) was similar in both arms.

RESULTS

The average follow-up was 36 months in both groups (range 9 to 60 months). No patient was excluded from the study. Although the percentage of patients with adverse events was higher in the ATG group (80 vs. 40%, P < 0.01), none of them resulted in premature discontinuation of the drug. Patients receiving ATG experienced a lower incidence (36% vs. 76%, P < 0.01) and number (13 vs. 29, P < 0.05) of acute renal rejection episodes. However, no difference was observed in patient, pancreas and kidney survival rates between groups. No case of isolated pancreas rejection was observed.

CONCLUSIONS

The quadruple sequential combination ATG, azathioprine, corticosteroid and CsA significantly reduced the one year incidence of acute renal rejection after SPK transplantation, compared to a triple immunosuppressive regimen.

Delayed graft function of more than six days strongly decreases long-term survival of transplanted kidneys

BACKGROUND

We reviewed 843 first cadaver kidney transplants carried out consecutively at our center to examine the effect on long-term graft survival of the duration of delayed graft function (DGF), defined as the time taken for the kidney to attain the threshold of a Cockcroft calculated creatinine clearance (cCCr) > or = 10 ml/min.

METHODS

Using a multivariate Cox survival analysis we evaluated the consequences of DGF on allograft survival, and then by regression analysis identified the factors contributing to the occurrence of DGF. Finally, using a Kaplan Meier analysis we compared the profiles of graft failure according to the duration of DGF.

RESULTS

Defining DGF in terms of cCCr rather than necessity for dialysis after transplantation allowed better prediction of long-term graft loss. Indeed, patients with a Cockcroft-based DGF > six days who did not require dialysis (12%) had a significantly poorer long-term graft outcome than those with a DGF < or = six days. Furthermore, we showed that a DGF of six days could be taken as a cut-off point that marked a significant difference in the long-term graft survival rate (P < 0.0001). Surprisingly, further extension of the duration of DGF > six days was not associated with further worsening of graft survival (except in DGF > 30 days).

CONCLUSION

Our results suggest a threshold effect in the lesions that ultimately results in long-term functional deficiency. In addition, we show that the need for dialysis is not an adequate criterium for DGF in terms of long-term outcome prediction.

Efficacy Endpoints Conference on Acute Rejection in Kidney Transplantation: review of the conference questionnaire

Basic differences in the diagnosis and management of acute rejection in renal transplant can be found between centers. A questionnaire was developed to ascertain the profile of these variables. Sixteen fundamental questions were presented to the program directors of 17 transplant groups from around the world. The questions were brief and designed to identify clinical practice and behaviors related to the definition of acute and steroid-resistant rejection, successful response to therapy, use of histological diagnosis, estimated frequency of rejection, and frequency of mild, moderate, or severe acute rejections. Clinicians were presented with case studies and asked to respond to specific questions regarding the rejection management described in these cases to determine similarities in management practices. Results indicated that clinicians relied on clinical symptoms only rarely. Biopsy findings were used by 53% of clinicians, and 94% of clinicians indicated that rejection was suspected if creatinine increased. Successful response was defined as a return to prerejection creatinine level by 77% of clinicians and that steroid-resistant rejection is evident by 5 days. Biopsy was used by 80% of centers to diagnose first acute rejection episode, and only 18% of rejection episodes are expected to be severe. This report was then used to develop a more detailed questionnaire to be used in profiling acute rejection in consecutive transplant recipients.

Comparing outcomes in renal replacement therapy: how should we correct for case mix?

The need to evaluate the effectiveness of clinical practice to justify expensive therapy in the face of financial constraints in all areas of health care delivery makes it necessary to identify groups of patients who are likely to benefit most from treatment. Various risk stratification methods have been used for analyzing survival probabilities for patients receiving renal replacement therapy. Complicated risk stratification methods produce large numbers of risk groups of small sizes, which makes comparison between individual centers difficult. We compared three simple methods of risk stratification, that divided patients into low-, medium-, and high-risk groups, in a cohort of 1,407 patients who commenced renal replacement therapy in five European countries during a 7-year period. Method 1 considered age (>55 years) and diabetes alone; method 2 used a higher age limit (>70 years) and comorbid illnesses, including those other than diabetes; and method 3 used only the number of comorbidities (none, 1, or > or =2) for stratification. Kaplan-Meier survival curves were constructed for comparison between risk groups and Cox's regression model used to assess strength of relationship with mortality. Although patient survival was significantly different between the low-, medium-, and high-risk groups using all three methods, Cox's regression analysis showed that method 2 provided the greatest discrimination between risk groups. In predicting mortality, method 2 (based on comorbidities and age) showed the highest sensitivity and specificity (84% and 80%, respectively) compared with method 1 (80% and 74%) and method 3 (64% and 82%). Validation of this approach in other populations in a prospective study is required before this method, which takes into account the influences of both age and comorbidity for risk stratification, can be used for comparing survival data and for presenting results of renal replacement therapy.

Effect of long-term immunosuppression in kidney-graft recipients on cancer incidence: randomised comparison of two cyclosporin regimens

BACKGROUND

Long-term administration of cyclosporin carries a risk of renal toxicity, and immunosuppressants are associated with an increased rate of malignant disorders. We undertook an open randomised study of the risks and benefits of two long-term maintenance regimens of cyclosporin in kidney-allograft recipients. The primary endpoint was graft function; secondary endpoints were survival and occurrence of cancer and rejection.

METHODS

231 recipients of a first allograft with at most one previous rejection episode were randomised 1 year after transplantation. Most were receiving cyclosporin and azathioprine. One group received cyclosporin doses adjusted to yield trough blood concentrations of 75-125 ng/mL (low-dose group); the second received doses that yielded trough concentrations of 150-250 ng/mL (normal-dose group). Analysis was by intention to treat.

FINDINGS

At 66 months' follow-up, the low-dose and normal-dose groups were similar in mean serum creatinine (182 [SD 160] vs 184 [157] micromol/L; p=0.9) and mean creatinine clearance (47.5 [25.1] vs 45.3 (22.5] mL/min; p=0.6). Nine of 116 patients in the low-dose group and one of 115 in the normal-dose group had symptoms of rejection (p<0.02). There was no difference between the low-dose and normal-dose groups in survival (95 vs 92%; p=0.7) or graft survival (89 vs 82%; p=0.17) at 6 years. 60 patients developed cancers, 37 in the normal-dose group and 23 in the low-dose group (p<0.034); 66% were skin cancers (26 vs 17; p<0.05).

INTERPRETATION

We found no evidence that halving of trough blood cyclosporin concentrations significantly changes graft function or graft survival. The low-dose regimen was associated with fewer malignant disorders but more frequent rejection. The design of long-term maintenance protocols for transplant recipients based on powerful immunosuppressant combinations should take these potential risks into account.

Disposition of basiliximab, an interleukin-2 receptor monoclonal antibody, in recipients of mismatched cadaver renal allografts

BACKGROUND

Basiliximab is an interleukin-2 receptor (IL-2R; CD25) chimeric monoclonal antibody for immunoprophylaxis against acute rejection in renal transplantation. Its pharmacokinetics were characterized in a multicenter open-label, prospective dose-escalation study to identify a single-dose regimen providing IL-2R-saturating serum concentrations in the critical first posttransplant month.

METHODS

Thirty-two recipients of primary, mismatched cadaver kidneys were enrolled: 20 men and 12 women, who were 47+/-11 years old and weighed 65+/-12 kg. The immunosuppression regimen consisted of steroids and azathioprine from day 0 and cyclosporine from day 10. Basiliximab was infused over 30 min as a single dose preoperatively.

RESULTS

Thirty patients were evaluable for basiliximab pharmacokinetics: 24 received 40 mg and 6 received 60 mg. Basiliximab was well tolerated without evidence of cytokine-release syndrome, hypersensitivity reactions, or anti-idiotype antibody response. Peak concentration and area under the concentration curve increased proportionally with dose. Postinfusion concentrations declined in a biphasic manner with a terminal half-life of 6.5+/-2.1 days. Weak, widely dispersed correlations were noted between body weight versus distribution volume (r=0.29) and versus clearance (r=0.45), suggesting no clinical relevance for weight-adjusted dosing. There were no apparent gender-related differences in basiliximab disposition. Previous phase II data indicated that serum concentrations in excess of 0.2 microg/ml are sufficient to saturate IL-2R epitopes on circulating T lymphocytes. Concentrations were above this threshold for 26+/-8 days (range 16 to 46) at the 40-mg dose level and for 32+/-11 days (range 22 to 51) at the 60-mg dose level.

CONCLUSIONS

Total basiliximab doses of 40-60 mg were well tolerated, nonimmunogenic, and estimated to provide immunoprophylaxis to cover the first posttransplant month.

Development of a method for direct quantification of cytomegalovirus antigenemia by flow cytometry

Cytomegalovirus (CMV) antigenemia was directly detected in polymorphonuclear leukocytes (PMNLs) from transplant recipients by using flow cytometry (FC). Two fixation and permeabilization methods and seven anti-CMV monoclonal antibodies (MAbs) were evaluated. 1C3, SL20, and NEA-9221 MAbs were more efficacious. The antigenemia detection threshold of FC was 0.05% positive PMNLs, and percentages correlated well with DNA viral load and the appearance of clinical symptoms.

Usefulness of DNA viral load quantification for cytomegalovirus disease monitoring in renal and pancreas/renal transplant recipients

BACKGROUND

The purpose of this prospective study was to evaluate the usefulness of quantifying DNA-cytomegalovirus (CMV) load for the diagnosis and monitoring of CMV disease among renal and pancreas transplant patients under immunosuppressive drugs.

METHODS

A longitudinal study was conducted among 34 consecutive, unselected renal and pancreas/renal transplanted patients in our unit. During the first 3 posttransplant months, weekly monitoring of CMV infection and CMV disease was done, involving the determination of viremia by the shell vial assay, qualitative DNAemia by semi-nested polymerase chain reaction (PCR) and quantitative DNAemia by the hybrid capture system (HCS), a new and original hybridization method (337 samples were collected for each test). Qualitative and quantitative DNAemia results were blinded to physicians and three grades of disease were defined according to CMV related symptom occurrence.

RESULTS

PCR was the most sensitive (100%) but the least specific (78%) method for the diagnosis of CMV disease. HCS was specific for CMV genome detection, sensitive and reproducible. Blood DNA levels above 60 pg/ml were predictive of severe or moderate CMV disease (sensitivity, 92%; specificity, 100%). A significant decrease in viral load was observed after ganciclovir administration, and a positive PCR or HCS result at the end of the antiviral treatment was associated with relapse of CMV infection or disease.

CONCLUSIONS

It is concluded that quantitative DNAemia detection, with this new commercially available method, can predict disease and may be useful for a rational evaluation of ganciclovir preemptive therapy in such patients.

Successful quantification of cytomegalovirus DNA by competitive PCR and detection with capillary electrophoresis

Human cytomegalovirus (HCMV) is responsible for severe infections in immunocompromised patients. Viral load has recently been identified as one of the major risk factors for subsequent development of HCMV disease. In this context, we developed a protocol allowing rapid, sensitive and precise quantification of HCMV DNA using competitive PCR run to saturation. Long primers were used for amplification, and internal DNA standard was constructed by PCR, with a primer inducing formation of a loop on the target sequence. The obtained fragment differed from the wild one (142 bp) by 6 bp. Quantitative analysis of PCR-amplified HCMV DNA was carried out using an original system combining capillary gel electrophoresis and u.v. detection. This procedure was evaluated on renal transplant recipients, and the results of quantitative PCR were compared with those of viraemia, qualitative DNAemia and HCMV-related symptoms. High levels of HCMV DNA were associated with HCMV-related symptoms, and in all cases a significant decrease of viral load was observed following DHPG treatment. Competitive PCR with capillary electrophoresis detection appears to provide a sensitive quantification method for HCMV DNA in leukocytes and is easily adaptable to routine laboratory use.

Anti-CD4 MoAb therapy in kidney transplantation--a pilot study in early prophylaxis of rejection

B-F5, a mouse IgG1 anti-CD4 MoAb, was used in recipients of a first cadaveric kidney allograft. Eighteen patients received 30 mg/day MoAb with a quadruple sequential therapy. All but one kidney were functioning at 6 months, with a mean serum creatinine of 153 micromol/L. However, 50% of the patients had an acute rejection episode within the first three months, and most of the early episodes (i.e., < 1 month) occurred in patients with low levels of circulating MoAb. The biological analysis showed a strong depleting effect on the CD4+ cell counts, a saturation by the MoAb of the remaining circulating CD4+ cells, and no detectable immunization against B-F5. Although the biological parameters indicate an action of B-F5 in vivo, the clinical data associated with poor MoAb bioavailability suggest the need for an improved pharmacokinetic behavior of the MoAb to determine its use for prophylaxis of early rejection.

[Economic contribution of mofetil mycofenolate as preventive immunosuppressive treatment after renal transplantation from cadaver]

OBJECTIVES

The economic impact resulting from the clinical consequences of immunosuppressive strategy using mycophenolate mofetil in new renal transplant recipients was conducted considering the viewpoint of the health insurance system.

METHODS

The analysis was based on the results of three controlled randomized double-blind clinical trials comparing mycophenolate mofetil with placebo or azathioprine in 1003 out of 1493 included patients respectively. Health care costs associated with each event were determined by 7 French experts in renal transplantation working in six different hospitals. Direct cumulative costs for each strategy were compared.

RESULTS

The studies demonstrated a difference in the incidence of acute rejection and treatment failures whatever the cause. The three trials showed that, compared with current strategies, use of mycophynolate mofetil in the immunosuppression protocol generated a 19 to 38% cost reduction during the 6 months after transplantation. Cost reduction resulted from lower incidence of acute rejection and the subsequent nephrectomics and dialysis sessions. The sensitivity analysis on the most important cost factors-cost of hospitalization per day and number of hospitalization days-confirmed strength of the results.

CONCLUSION

Use of mycophenolate mofetil in the immunosuppressive prophylaxis protocol after renal transplantation allows a reduction in the direct costs during the 6 months following transplantation.

Survival on renal replacement therapy in Europe: is there a 'centre effect'?

OBJECTIVE

Survival is the ultimate outcome measure in renal replacement therapy (RRT) and may be used to compare performance among centres. Such comparison, however, is meaningless if the influences of comorbidity, age and early deaths are not considered. We therefore studied survival rates on RRT in seven centres in Europe after taking into account the influence of age, early deaths, primary renal diagnoses, and comorbidity.

DESIGN

A retrospective survival analysis was carried out on 1407 patients who commenced RRT in seven centres across five European countries during a 7-year period. Patients were stratified into low-, medium- and high-risk groups based mainly on comorbidity and to a lesser extent on age at commencement of RRT. Kaplan-Meier survival and Cox's proportional hazards model were used to compare survival.

RESULTS

Before risk stratification overall 2-year survival across the seven centres ranged from 60.2 to 85.3% (69.3-89.9%) after excluding early deaths) masking a range of survivals of 27.4% for the high-risk group with the worst survival to 100% in the low-risk group with the best survival. After excluding early deaths 2-year survival in the low risk groups (n=622) was greater than 90% in all centres. Multivariate analysis showed that the mortality risk increased four fold from low- to medium- and a further 1.6-fold from medium- to high-risk group. However, despite this adjustment for comorbidity and age there still remained a significant difference in survival among some centres, i.e. a 'centre effect' which ranked the centres.

CONCLUSION

Risk stratification diminishes the variance in survival between centres but a centre effect remains despite adjusting for age and comorbidity. Multicentre prospective studies are urgently required to identify the reasons for this apparent centre effect.

Single-center analysis of 468 first cadaveric kidney allografts with a uniform ATG-CsA sequential therapy

Progress in clinical management and sophistication of immunological treatment of kidney allografts depend upon continuous reassessment of the risk factors related to pre- and post-graft information according to the therapeutical strategies used. We studied predictive factors of long-term graft survival (up to 9 years) and of kidney graft function at one year after surgery in a single-center population of 468 first cadaveric kidney recipients treated with a uniform immunosuppression induction regimen of anti-thymocyte globulin, followed by cyclosporine A. The statistical analysis showed that long-term graft survival was highly correlated with the occurrence of one or more acute cellular rejections and with the timing of these episodes. In addition, this uniformly treated series of patients confirmed the potential importance of gender matching. The magnitude of anti-HLA immunization and delayed graft function were also strongly linked to low graft survival rates. We found no significant influence of HLA matching, with serological HLA typing, on graft loss. The quality of graft function at one year was found to be a strong prognostic factor of long-term graft survival. In addition, the impact of pre- and post-graft parameters were studied in terms of prediction of one-year graft function. A stepwise multivariate analysis showed that graft function at one year was a multivariate phenomenon strongly correlated with a history of acute rejection episodes and with donor and recipient age. However, these 3 factors could account for only 15% of the graft function deterioration, the remaining 85% might be explained in part by chronic cyclosporine toxicity and/or chronic rejection.

Late acute failure of well-HLA-matched renal allografts with capillary congestion and arteriolar thrombi

Seventeen cases of a histologically and clinically unusual renal acute dysfunction in kidney recipients, individualized among a population of 1378, are reported. The basic histological lesion was a huge capillary congestion, associated with capillary and arteriolar thromboses or parenchymal necrosis in most patients, and contrasting with the absence of the classical features of acute cellular rejection, i.e., tubulitis, glomerulitis, edema, and infiltrate. The corresponding clinical history was characterized by its early timing in the course of transplantation (< 3 months), its sudden occurrence in patients usually having good transplant function, leading to end-stage renal failure in a few days, and its resolution under rejection treatment. The occurrence of this syndrome was significantly linked with a good HLA matching: 13 of the 17 recipients were HLA-DR matched (P < 0.0001). The etiology of this syndrome remains unknown. There was no evidence for graft vessel thrombosis. Because of some histological similarities, the usual causes of the hemolytic uremic syndrome, including bacterial and viral infections or cyclosporine arteriolopathy, were discussed. Acute vascular rejection was suspected, but the cross-match was negative on T lymphocytes in all cases and anti-HLA class I and II antibodies were not found to develop at the time of transplant dysfunction, except in 1 patient, in whom the detected anti-DR antibodies were not directed at the kidney donor. Anti-human umbilical vein endothelial cell antibodies, detected in an antibody-dependent cellular cytotoxicity assay, were present in 6 patients (of the 14 tested) at the onset of renal failure, but they were either absent (n = 3) or already present at the time of transplantation (n = 5) in the other 8 patients. Therefore, reliable arguments are lacking to conclude that this acute transplant dysfunction is an acute vascular rejection and its strong association with HLA matching has, as yet, no satisfactory explanation.

Graft-infiltrating T helper cells, CD45RC phenotype, and Th1/Th2-related cytokines in donor-specific transfusion-induced tolerance in adult rats

Specific tolerance to LEW.1W (RT1u) heart allografts can be induced in adult LEW.1A (RT1a) rats by donor-specific blood transfusion (DST). We have previously shown that both rejected and tolerated grafts are heavily infiltrated by T lymphocytes, and that in both cases these T cells are capable of developing similar cytotoxic responses against donor cells in vitro; tolerance is therefore not due to the deletion of alloreactive T cells. At the same time, we found that the accumulation of IL-2 and IFN-gamma mRNA was decreased in tolerated grafts compared with rejected grafts. These results suggested that the induction of allograft tolerance in DST-treated animals could be mediated by anergy or suppression of graft-infiltrating Th1 cells. Although Th1 and Th2 clones have not yet been characterized in the rat, peripheral CD4+ rat T cells can be divided into two populations, based on their expression of the isoform RC of the CD45 molecule. Upon activation, CD45RChigh CD4+ T cells produce IL-2 and IFN-gamma and responsible for the induction of the graft-versus-host reaction, whereas CD45RClow CD4+ T cells produce IL-4 in vitro and provide B cell help. In the present study, we show that heart allografts from both DST-treated and untreated rats were infiltrated by equivalent numbers of leukocytes, of which CD4+ T cells also made up similar percentages. Among these CD4+ T cells, we observed that in allografts from DST-treated recipients the CD45RChigh population on day 5 was very significantly smaller (P = 0.004) than in the untreated group, while CD45RClow populations remained comparable. Moreover, using a new quantitative RT-PCR method, we found a dramatic reduction in the accumulation of IL-2, IFN-gamma, IL-10, IL-4, and IL-13 mRNA in hearts from DST-treated recipients compared with those of untreated recipients during the week following transplantation. These results show that in heart allografts from DST-treated recipients, despite phenotypic changes suggesting Th1 inhibition by Th2 imbalance, T helper function was inhibited as a whole, and that in vivo the phenotype CD4+ CD45RClow does not always correlate with Th2-related cytokine-producing cells.

Prolongation of allogeneic heart graft survival in rats by administration of a peptide (a.a. 75-84) from the alpha 1 helix of the first domain of HLA-B7 01

Allospecific T lymphocytes mediate graft rejection through specific, direct or indirect, recognition of processed determinants of foreign MHC class I molecules. Small synthetic peptides derived from highly conserved sequences of the alpha 1 helix of the first domain of certain MHC class I molecules have been shown to inhibit CTL responses in vitro and to prolong graft survival in rats when combined with subtherapeutic doses of cyclosporine. Here, we report that the survival of LEW.1W heart allografts was significantly prolonged when transplanted into congenic LEW.1A recipients treated only with a peptide corresponding to residues 75-84 of the human HLA-B7-01 molecule (B7.75-84) before transplantation. The experimental value for mean survival time (+/- SD) in untreated recipients was 13 +/- 6 days and in peptide-treated recipients was 42 +/- 27 days (P < 0.002). A total of 64% of treated recipients had a functioning graft at 30 days, while grafts were rejected in all rats belonging to the control group within this time. Within graft-infiltrating leukocytes (GIL) in B7.75-84-treated animals, the proportion of T cells was significantly lower and that of CD5-/TCR alpha beta-/CD16-/CD8+ and MHC class II+ cells concomitantly increased, as compared with nontreated animals. GIL from B7.75-84-treated animals also exhibited a dramatic decrease (approximately 70%) of allospecific and spontaneous (NK) cytotoxic activity, whereas their proliferation and IL-2 production were similar in both experimental groups. The IFN-gamma, IL-2, and IL-10 mRNA levels from GIL from peptide-treated recipients were similar to levels of controls, reflecting a state of activation of GIL. Perforin and granzyme A mRNA, the level of which may be modulated parallel to impaired cytotoxic functions, were at similar levels in both experimental groups. These data demonstrate that B7.75-84 significantly prolongs graft survival in LEW.1A rats when given as a single agent and suggests that a specifically decreased cytotoxic response (allospecific and spontaneous) plays a major role.

Decreased anti-donor major histocompatibility complex class I and increased class II alloantibody response in allograft tolerance in adult rats

Permanent tolerance to allografts can be induced in adult rats by donor-specific transfusions (DST) prior to transplantation. We have previously reported, in a model of heart allograft, the presence of a heavy leukocyte infiltrate, in the allograft which displayed a strong allospecific cytotoxicity when tested in vitro against donor cells, and a strong accumulation of mRNA for granzyme A and perforin in vivo. In contrast, there was a major decrease in the accumulation of mRNA for interleukin-2 and interferon-gamma. These results suggested that the DST-induced tolerance was associated with a decrease in type-1 T helper (Th1) cell function. The major role of preformed antibodies in xeno and allorejection is clearly established. Nevertheless, the consequences of alloantibody production in acute rejection and tolerance induction remains to be elucidated. We here analyze the alloantibody response in rejecting and DST-treated recipients. We show that, after transplantation, tolerant recipients, in contrast to rejecting ones, mount a low IgM alloresponse that switches to low IgG production. Detailed analysis of IgG alloantibodies in DST-treated recipients revealed that their production decrease was not equally distributed. Whereas rejecting animals mounted a strong anti-class I and II IgG alloantibody response, DST-treated recipients produced anti-class II and low titers of anti-class I IgG alloantibodies. Furthermore, among IgG subclasses, tolerant recipients predominantly produced IgG2a, a profile which, in the rat, is compatible with a Th2-controlled response. Finally, the passive transfer of immune serum from rejecting animals to DST-treated recipients could abrogate the tolerance. We suggest that the absence of anti-class I alloantibodies combined with preserved and/or increased anti-class II production plays a major role in graft tolerance in this model. These results reinforced the role of alloantibodies in rejection and in induction of tolerance.