The Banff 2017 Kidney Meeting Report: Revised diagnostic criteria for chronic active T cell-mediated rejection, antibody-mediated rejection, and prospects for integrative endpoints for next-generation clinical trials

The kidney sessions of the 2017 Banff Conference focused on 2 areas: clinical implications of inflammation in areas of interstitial fibrosis and tubular atrophy (i-IFTA) and its relationship to T cell-mediated rejection (TCMR), and the continued evolution of molecular diagnostics, particularly in the diagnosis of antibody-mediated rejection (ABMR). In confirmation of previous studies, it was independently demonstrated by 2 groups that i-IFTA is associated with reduced graft survival. Furthermore, these groups presented that i-IFTA, particularly when involving >25% of sclerotic cortex in association with tubulitis, is often a sequela of acute TCMR in association with underimmunosuppression. The classification was thus revised to include moderate i-IFTA plus moderate or severe tubulitis as diagnostic of chronic active TCMR. Other studies demonstrated that certain molecular classifiers improve diagnosis of ABMR beyond what is possible with histology, C4d, and detection of donor-specific antibodies (DSAs) and that both C4d and validated molecular assays can serve as potential alternatives and/or complements to DSAs in the diagnosis of ABMR. The Banff ABMR criteria are thus updated to include these alternatives. Finally, the present report paves the way for the Banff scheme to be part of an integrative approach for defining surrogate endpoints in next-generation clinical trials.

Real Time Central Assessment of Kidney Transplant Indication Biopsies by Microarrays: The INTERCOMEX Study

The authors conducted a prospective trial to assess the feasibility of real time central molecular assessment of kidney transplant biopsy samples from 10 North American or European centers. Biopsy samples taken 1 day to 34 years posttransplantation were stabilized in RNAlater, sent via courier overnight at ambient temperature to the central laboratory, and processed (29 h workflow) using microarrays to assess T cell- and antibody-mediated rejection (TCMR and ABMR, respectively). Of 538 biopsy samples submitted, 519 (96%) were sufficient for microarray analysis (average length, 3 mm). Automated reports were generated without knowledge of histology and HLA antibody, with diagnoses assigned based on Molecular Microscope Diagnostic System (MMDx) classifier algorithms and signed out by one observer. Agreement between MMDx and histology (balanced accuracy) was 77% for TCMR, 77% for ABMR, and 76% for no rejection. A classification tree derived to provide automated sign-outs predicted the observer sign-outs with >90% accuracy. In 451 biopsy samples where feedback was obtained, clinicians indicated that MMDx more frequently agreed with clinical judgment (87%) than did histology (80%) (p = 0.0042). In 81% of feedback forms, clinicians reported that MMDx increased confidence in management compared with conventional assessment alone. The authors conclude that real time central molecular assessment is feasible and offers a useful new dimension in biopsy interpretation. ClinicalTrials.gov NCT#01299168.

The Banff 2015 Kidney Meeting Report: Current Challenges in Rejection Classification and Prospects for Adopting Molecular Pathology

The XIII Banff meeting, held in conjunction the Canadian Society of Transplantation in Vancouver, Canada, reviewed the clinical impact of updates of C4d-negative antibody-mediated rejection (ABMR) from the 2013 meeting, reports from active Banff Working Groups, the relationships of donor-specific antibody tests (anti-HLA and non-HLA) with transplant histopathology, and questions of molecular transplant diagnostics. The use of transcriptome gene sets, their resultant diagnostic classifiers, or common key genes to supplement the diagnosis and classification of rejection requires further consensus agreement and validation in biopsies. Newly introduced concepts include the i-IFTA score, comprising inflammation within areas of fibrosis and atrophy and acceptance of transplant arteriolopathy within the descriptions of chronic active T cell-mediated rejection (TCMR) or chronic ABMR. The pattern of mixed TCMR and ABMR was increasingly recognized. This report also includes improved definitions of TCMR and ABMR in pancreas transplants with specification of vascular lesions and prospects for defining a vascularized composite allograft rejection classification. The goal of the Banff process is ongoing integration of advances in histologic, serologic, and molecular diagnostic techniques to produce a consensus-based reporting system that offers precise composite scores, accurate routine diagnostics, and applicability to next-generation clinical trials.

[Adherence to treatment after kidney transplantation as quality indicator of the information received: Longitudinal study of 2 years follow-up]

INTRODUCTION

Transplantation is an optimal form of treatment for end-stage renal disease, but requires lifelong adherence to immunosuppressive therapy. The aim of this study was to longitudinally assess the adherence to treatment after kidney transplant, as well as to compare the amount of information about the treatment received at one month and 18 months post-transplantation, and its influence on adherence to treatment.

MATERIAL AND METHODS

The Self-Reported Measure of Medication Adherence was administered at month (T1), 6 months (T2), 12 months (T3), 18 months (T4), and 24 months (T5) post-transplantation. Survey about aspects of knowledge and attitudes about medication, was administered at one month and 18 months post-transplant. Measures of central tendency and non-parametric tests were used to compare the data.

RESULTS

The study included a total of 73 patients with a median age of 57 years. The percentage of patients non-adherent to medication was 9.6% (T1), 22.5% (T2), 29.2% (T3), 29.8% (T4), and 28.1% (T5). One month after transplantation "not consulting with the doctor on forgetting to take medication (P=.034) significantly influenced the non-adherence to treatment. At 18 months post- transplantation, none of the issues raised on medication knowledge had an influence on non-adherence to treatment.

CONCLUSIONS

Longer times since transplantation increased the non-adherence to treatment. Some issues regarding the information of treatment influenced the non-adherence in the immediate transplant period, but not in the follow-up.

Native ureteropyelostomy in the treatment of obstructive uropathy in adult renal transplant. Experience and technical alternatives

OBJECTIVE

To analyze and evaluate our experience in surgical treatment with the open approach of the complex ureteral stenosis after adult kidney transplantation in a tertiary level hospital in the last seven years. We have reviewed the different surgical options used.

PATIENTS AND METHODS

A total of 589 consecutive adult renal transplants were performed from January 2005 to December 2012. Of these, 1.1% showed some degree of symptomatic obstructive uropathy which after initial urinary diversion required open surgical approach using the ipsilateral or contralateral native urinary tract. Characteristics of the patient, clinical examinations performed and surgical technique performed as well as their results are presented.

RESULTS

During the period under review, in 5 men and 2 women who had ureteral stenoses after renal transplant, 7 reparative surgeries were performed by open ureteropyelostomy, using ipsilateral native ureter in 6 cases and contralateral ureter in the remaining case. In one case, uretero-calicial anastomosis was performed due to severe pyelic shrinkage. There were no significant complications. Native kidney nephrectomy was not required for further complications. All the patients operated on had optimum plasma creatinine levels with resolution of previous dilatation.

CONCLUSIONS

The initial percutaneous nephrostomy followed by open surgical repair using native ureter represents a definitive, valid and optimal alternative in terms of safety and preservation of renal function.

Banff '09 meeting report: antibody mediated graft deterioration and implementation of Banff working groups

The 10th Banff Conference on Allograft Pathology was held in Banff, Canada from August 9 to 14, 2009. A total of 263 transplant clinicians, pathologists, surgeons, immunologists and researchers discussed several aspects of solid organ transplants with a special focus on antibody mediated graft injury. The willingness of the Banff process to adapt continuously in response to new research and improve potential weaknesses, led to the implementation of six working groups on the following areas: isolated v-lesion, fibrosis scoring, glomerular lesions, molecular pathology, polyomavirus nephropathy and quality assurance. Banff working groups will conduct multicenter trials to evaluate the clinical relevance, practical feasibility and reproducibility of potential changes to the Banff classification. There were also sessions on quality improvement in biopsy reading and utilization of virtual microscopy for maintaining competence in transplant biopsy interpretation. In addition, compelling molecular research data led to the discussion of incorporation of omics-technologies and discovery of new tissue markers with the goal of combining histopathology and molecular parameters within the Banff working classification in the near future.

Banff 07 classification of renal allograft pathology: updates and future directions

The 9th Banff Conference on Allograft Pathology was held in La Coruna, Spain on June 23-29, 2007. A total of 235 pathologists, clinicians and scientists met to address unsolved issues in transplantation and adapt the Banff schema for renal allograft rejection in response to emerging data and technologies. The outcome of the consensus discussions on renal pathology is provided in this article. Major updates from the 2007 Banff Conference were: inclusion of peritubular capillaritis grading, C4d scoring, interpretation of C4d deposition without morphological evidence of active rejection, application of the Banff criteria to zero-time and protocol biopsies and introduction of a new scoring for total interstitial inflammation (ti-score). In addition, emerging research data led to the establishment of collaborative working groups addressing issues like isolated 'v' lesion and incorporation of omics-technologies, paving the way for future combination of graft biopsy and molecular parameters within the Banff process.

Immunephenotype of glomerular and interstitial infiltrating cells in protocol renal allograft biopsies and histological diagnosis

Patients with a protocol renal allograft biopsy simultaneously displaying interstitial fibrosis/tubular atrophy (IF/TA) and subclinical rejection (SCR) have a shortened graft survival than patients with a normal biopsy, or with a biopsy only displaying IF/TA or SCR. The poor outcome of these patients could be related with a more severe inflammation. We evaluate the immunophenotype of infiltrating cells in these diagnostic categories. Nonexhausted paraffin blocks from protocol biopsies done during the first year were stained with anti-CD45, CD3, CD20, CD68 and CD15 monoclonal antibodies. Glomerular and interstitial positive cells were counted. C4d deposition in peritubular capillaries was evaluated. Histological diagnoses were: normal (n = 80), SCR (n = 17), IF/TA (n = 42) and IF/TA + SCR (n = 17). Only interstitial CD20 positive cells were significantly increased in patients displaying IF/TA + SCR; normal (137 +/- 117), SCR (202 +/- 145), IF/TA (208 +/- 151) and IF/TA + SCR (307 +/- 180 cells/mm(2)), p < 0.01. The proportion of biopsies displaying C4d deposition was not different among groups. The upper tertile of CD20 positive interstitial cells was associated with a decreased death-censored graft survival (relative risk: 3.01, 95% confidence interval: 1.23-7.35; p = 0.015). These data suggest that B-cell interstitial infiltrates are associated with histological damage and outcome, but do not distinguish whether these infiltrates were the cause or the consequence of chronic tubulo-interstitial damage.

Banff '05 Meeting Report: differential diagnosis of chronic allograft injury and elimination of chronic allograft nephropathy ('CAN')

The 8th Banff Conference on Allograft Pathology was held in Edmonton, Canada, 15-21 July 2005. Major outcomes included the elimination of the non-specific term "chronic allograft nephropathy" (CAN) from the Banff classification for kidney allograft pathology, and the recognition of the entity of chronic antibody-mediated rejection. Participation of B cells in allograft rejection and genomics markers of rejection were also major subjects addressed by the conference.

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

BACKGROUND

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

PATIENTS

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

RESULTS

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

CONCLUSIONS

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

Early diagnosis of chronic allograft nephropathy by means of protocol biopsies

Chronic allograft nephropathy (CAN) is the first cause of graft failure. Since graft survival has improved and the incidence of rejection decreased, these outcomes cannot be employed as primary efficacy variables in clinical trials due to the need for a large sample size. The presence of CAN in protocol biopsies is an independent predictor of graft survival. Thus, it has been proposed that chronic lesions in protocol biopsies be considered a primary efficacy variable. Power calculations have confirmed this hypothesis, especially if CAN is evaluated using a morphometric technique. Moreover, it has been demonstrated that in vivo glomerular number (Ng) can be estimated by combining a protocol biopsy with magnetic resonance imaging. Ng correlates with graft function in stable grafts. Taken together, these data suggest that protocol biopsies constitute a fundamental tool to improve the design of clinical trials and to define parameters that are crucial to the understanding of mechanisms leading to CAN.

Renal protective effect of liposomed superoxide dismutase in an experimental warm ischemia model

Superoxide dismutase (SOD) is a potent scavenger of superoxide radicals produced during normothermic ischemia-reperfusion. Since it has a short half-life, its optimal effect is achieved when it is given prior to reperfusion. The inclusion of SOD in liposomes (lipo-SOD) prolongs its half-life (free SOD: 6 min; lipo-SOD: 4 h). The protective effect of lipo-SOD in a 60-min bilateral renal warm ischemia model was studied. We divided 60 male Wistar rats between two control groups and five study groups according to the drug used (SOD or lipo-SOD) and to the time of SOD administration (prior to ischemia or prior to reperfusion). SOD and lipo-SOD were both given at 20 mg/kg endovenously. Weight, diuresis, creatinine per 100 g (Cr/100 g), and creatinine clearance per 100 g (CrCl/100 g) were studied. Conventional renal histology was performed after reperfusion and on day 7. Renal malondialdehyde, 6 keto PGF 1 alpha, and TxB2 tissue levels were studied after reperfusion. Results showed that the renal protective effect of free SOD on warm ischemic-reperfusion injury depended on the time of administration, being more effective when given before reperfusion. On the other hand, the renal protective effect of liposomed SOD did not depend on the time of administration since efficacy was similar when given before reperfusion or before ischemia. The functional protective effect of liposomed SOD was similar to that of free SOD when they were given prior to reperfusion. Nevertheless, since histological damage observed with liposomed SOD was less than with free SOD, it is suggested that the liposomed galenic form may offer better protection against renal warm ischemia. In addition, liposomed SOD was better at preventing tissue prostanoid generation after renal warm ischemic-reperfusion injury than free SOD. We concluded that liposomed SOD shows a higher renal protective effect against warm ischemia than free SOD.

Primary immunosuppression with mycophenolate mofetil and antithymocyte globulin for kidney transplant recipients of a suboptimal graft

BACKGROUND

In renal transplantation the beneficial immunosuppressive effects of cyclosporin (CsA) may be curtailed by its nephrotoxicity, specially in patients receiving a cadaveric allograft from suboptimal donors or at risk of delayed graft function. Mycophenolate mofetil (MMF) and antithymocyte globulin (ATG) have each demonstrated to be potent immunosuppressants in renal transplantation. In a prospective analysis we have studied the results at 6 months of the combination of MMF, ATG and low-dose steroids in patients with low immunological risk receiving a first cadaveric renal allograft from a suboptimal donor or at risk of delayed graft function.

METHODS

Patients with preformed reactive antibodies < 500% receiving a first graft from a suboptimal donor (age > or = 40 years, non-heart-beating, acute renal failure, arterial hypertension) or at risk of delayed graft function (cold ischaemia time > or = 24 h) were eligible for this open single-arm pilot trial. From September 1996 to March 1997 we recruited 17 patients. They were treated with MMF 2 g p.o. preoperatively, and after transplantation at 3 g/day; rabbit ATG i.v. at 2 mg/kg preoperatively, and 1.5 mg/kg/day the first day after transplantation, followed by four doses of 1 mg/kg on alternate days; prednisone was given at 0.25 mg/kg/day and reduced progressively to 0.1 mg/kg/day at 3 months. Primary outcomes were incidence of biopsy-proven acute rejection, delayed graft function, opportunistic infections, graft and patient survival, and the need for introduction of CsA treatment.

RESULTS

delayed graft function occurred in two cases (12%). Four of 17 patients (24%) had a biopsy-proven acute rejection (2 grade I and 2 grade II) within the first 3 months after transplantation. CsA was added in two cases with grade II biopsy-proven acute rejection, and in one with grade I biopsy-proven acute rejection. In one patient MMF was replaced by CsA because of gastrointestinal intolerance. Mean serum creatinine 6 months after transplantation was 159+/-59 micromol/1. Cytomegalovirus tissue invasive disease occurred in one patient (6%). At 6 months follow-up all patients are alive with functioning allografts.

CONCLUSIONS

These preliminary results suggest that in low-immunological-risk patients who receive a suboptimal renal allograft or at risk of delayed graft function, the combination of MMF, ATG, and steroids is an efficient immunosuppressive regime that may avoid the use of CsA in 70% of the recipients.

Hepatitis C virus-associated membranoproliferative glomerulonephritis in renal allografts

In renal transplantation, chronic allograft nephropathy is the leading cause of long-term graft losses, transplant glomerulopathy being its glomerular form. Differential diagnosis from recurrent or de novo membranoproliferative glomerulonephritis should be established. Whether hepatitis C virus is associated with cryoglobulinemia and glomerular damage in renal allograft recipients, as in native kidneys, is not known. We identified six hepatitis C virus-infected renal allograft recipients with proteinuria higher than 1.5 g/day, microhematuria, and membranoproliferative glomerulonephritis. Virologic and immunologic studies were conducted. Low serum levels of circulating immune complexes and cryoglobulins were observed, which were type II immunoglobulin G polyclonal-immunoglobulin Mk monoclonal in all six patients. Classical serum complement pathway activation and at least one type of autoantibodies were present in all of them. Hepatitis C virus RNA was found in higher concentrations in cryoprecipitate than in serum (percentage of enrichment ranged from 341 to 18,200%). Hepatitis C virus genotype was 1b in 4 of 6 patients, 1a in 1 of 6 patients, and 2a in 1 of 6 patients. In renal histology prominent parietal diffuse deposition of immunoglobulin M was the rule. Glomerular subendothelial electron-dense deposits with fibrillar appearance were observed in the two patients in which electron microscopy provided information about glomeruli. In renal allograft recipients hepatitis C virus infection may be associated with type II cryoglobulinemia which may lead to membranoproliferative glomerulonephritis. Immunologic and virologic studies may help to differentiate hepatitis C virus-associated membranoproliferative glomerulonephritis from transplant glomerulopathy.

Fibronectin (FN) decreases glomerular lesions and synthesis of tumour necrosis factor-alpha (TNF-alpha), platelet-activating factor (PAF) and FN in proliferative glomerulonephritis

We have studied the effect of therapy with plasma FN on glomerular synthesis of PAF, TNF-alpha and FN, in experimental proliferative glomerulonephritis. Glomerular PAF, TNF-alpha and FN production were increased in rats with nephritis. Peak glomerular PAF production preceded, while peak glomerular TNF-alpha bioactivity coincided with maximal proteinuria. Rats treated with FN (5 mg/kg per 48 h) for 15 days had less proteinuria, glomerular and interstitial cell infiltration and glomerular PAF, TNF-alpha and FN synthesis than non-treated rats. In order to characterize further the mechanisms of action of FN, healthy rats were injected with either FN or saline. Peripheral blood mononuclear cells and neutrophils from healthy rats injected with FN secreted less TNF-alpha and PAF, respectively, than those obtained from saline-treated rats. Our data suggest that the beneficial effect of FN may be related to decreased number of glomerular leucocytes and decreased synthesis of inflammatory mediators and extracellular matrix.

Effect of ciclosporin on serum lipids and modification with LSL 90202, a lysine salt of eicosapentaenoic acid

Ciclosporin (CS-A) has recently been considered a separate risk factor for the development of hyperlipidemia in transplant patients. In the present work, the effect of chronic CS-A administration on serum lipids and its modification using dietary supplementation with LSL 90202, a lysine salt of eicosapentaenoic acid, was studied. Thirty-one male Wistar rats were divided into four groups, receiving (1) 20 mg/kg CS-A in olive oil (CS-A group; n = 8); (2) isovolumetric olive oil (olive oil groups; n = 8); (3) 20 mg/kg CS-A in olive oil plus 20 mg/kg LSL 90202 (CS-A + LSL 20 group;) and (4) 20 mg/kg CS-A in olive oil plus 40 mg/kg LSL 90202 (CS-A+LSL 40 group; n = 8). Both, CS-A and LSL 90202 were given by daily gavage. On day 28, CS-A whole-blood levels and serum levels of total cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol fractions (HDL, HDL-2, HDL-3, non-HDL), and malondialdehyde were measured. On day 28, the rats given CS-A showed significantly higher cholesterol, triglyceride, and non-HDL cholesterol serum levels than rats given olive oil. Rats given CS-A and LSL 90202 (20 mg/kg) showed significantly lower triglyceride serum levels than rats given CS-A only. Rats given CS-A and LSL 90202 (40 mg/kg) showed significantly lower triglyceride, total cholesterol, and non-HDL cholesterol serum levels than rats given CS-A only. There were no differences in HDL, HDL-2, and HDL-3 cholesterol serum levels between the groups. The CS-A whole-blood levels were not different between groups of animals given CS-A.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of experimental cyclosporine nephrotoxicity by dietary supplementation with LSL 90202, a lysine salt of eicosapentaenoic acid. Role of thromboxane and prostacyclin in renal tissue

Cyclosporine (CsA) nephrotoxicity is partially mediated by renal vasoconstriction due to an imbalance between vasodilator and vasoconstrictor eicosanoids. LSL 90202 is a purified lysine salt of eicosapentaenoic acid which is a known inhibitor of renal eicosanoid synthesis. The aim of the present work was to determine if chronic dietary supplementation with LSL 90202 prevented CsA nephrotoxicity and to establish the role of thromboxane and prostacyclin in renal tissue. Thirty-three male Sprague-Dawley rats were divided into 4 groups: group 1, CsA in olive oil (n = 10); group 2, isovolumetric olive oil (n = 7); group 3, CsA in olive oil plus LSL 90202 (n = 8); group 4, isovolumetric olive oil plus LSL 90202 (n = 8). CsA and LSL 90202 were given at 20 mg/kg/day. Weight and creatinine clearance (CrCl) were determined before and on days 14 and 30. On day 30 whole-blood CsA was determined and renal tissue processed for renal malondialdehyde, thromboxane B2 and 6-keto-PGF1 alpha measurement and for conventional histology. CrCl was severely reduced in the CsA in olive oil group compared to olive oil and LSL 90202 control groups. On day 30, CrCl in the CsA in olive oil plus LSL 90202 group showed a slight decrease, but the mean CrCl was significantly higher than in the CsA in olive oil group. Trough whole blood CsA levels were not significantly different in both groups given the drug. No morphological differences were found between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of the PAF antagonist BN 52021 in an experimental renal warm ischemia model

Platelet activating factor is involved in warm ischemic damage. We studied the effect of the PAF receptor antagonist BN 52021 in an experimental model of 60 min of renal warm ischemia in which the left kidney was flushed with Euro-Collins solution and a right nephrectomy was performed. Eighty Wistar rats were divided into a sham-operated group, two control groups, and four study groups, according to the dosage and route of BN 52021 administration. BN 52021 was used in the flush solution at concentrations of 0.1 and 0.5 mg/ml, or intravenously prior to ischemia at 5 and 10 mg/kg body weight. Creatinine clearance per 100 g body weight, fractional sodium excretion, and conventional histology were studied. Rats that received BN 52021 intravenously showed a significantly higher creatinine clearance than controls. Intravenous BN 52021 produced a higher acceleration of renal function recovery at 10 mg/kg than at 5 mg/kg body weight. Conventional histology was better in animals that received BN 52021 at 10 mg/kg body weight than in controls. Addition of BN 52021 to Euro-Collins flushing solution showed no protective effect. We conclude that intravenous BN 52021 shows a renal protective effect against warm ischemia.

Cyclosporin A (CsA) and azathioprine (AZA) combination in renal allografts with CsA nephrotoxicity

Cyclosporin A (CsA) is a potent immunosuppressive drug whose effect is well known in the organ transplantation field. Treatment with CsA reduces the incidence of rejection and improves graft survival after renal transplantation (RT). However, to set against the clear advantages of CsA, a most important problem is nephrotoxicity. Scientists are therefore seeking new non-nephrotoxic Cs derivatives, but the search has not yet borne fruit. Teams working in organ transplantation attempt to avoid nephrotoxicity by switching to conventional treatment with azathioprine (AZA), starting 1, 3 or 6 months after transplantation. Conversion from CsA to AZA has not always been successful due to the high incidence of rejection. AZA has also been started immediately after transplantation in combination with CsA at low doses, and in some instances no CsA is administered when oliguric acute tubular necrosis is present. In a previous report, we presented the short-term results of the treatment with a CsA-AZA combination, reducing the CsA dose and giving a moderate dose of AZA in 21 transplanted patients not achieving acceptable graft function. In the present study we analysed the long-term results in a group of patients whose kidney biopsy examination results were compatible with CsA nephrotoxicity.

[Antilymphocyte serum, cyclosporine and corticoids, versus OKT3, cyclosporine, and corticoids in kidney transplantation]

The use of the antilymphoblast globulin (ALG) or OKT3 associated with cyclosporine (CyA) and steroids has been useful in kidney cadaveric transplantation. 101 patients who received their first cadaveric renal transplant were randomized according to the immunosuppression used. Group A (n = 53): horse ALG 15 mg/kg just before transplant surgery; ALG 12 mg/kg on the first day after transplant followed by 4 doses of 10 mg/kg on alternate days; Cya p.o 8 mg/kg/d; prednisone 0.25 mg/kg/d. Group B (n = 48): OKT3 5 mg just before transplant followed by 4 doses of 5 mg/d.; CyA and prednisone were administered using the same schedule as group A.

RESULTS

the incidence of rejection during the first 3 months was: group A: 13 percent, group B: 17 percent (NS). The probability of being free of acute rejection (Kaplan-Meier) 24 months after transplant was 89 percent in group A and 79 percent in group B (NS). The day of onset of the first acute rejection episode was 25 +/- 20 days after transplant in group A, and 17 +/- 10 day in group B (NS). Incidence of tubular necrosis: group A 21 percent, group B 19 percent (NS).

Expression of VCAM-1 in the normal and diseased kidney

We have conducted an immunocytochemical analysis to investigate the presence of the recently described vascular cell adhesion molecule-1 (VCAM-1) in human kidney, using the anti-VCAM-1 monoclonal antibody 1.4C3. In normal control tissue VCAM-1 was present on some (but not all) parietal epithelial cells lining Bowman's capsule. Forty-nine of fifty clinical biopsy specimens were characterised by the additional presence of VCAM-1 on proximal tubular cells. This was most marked in biopsies of patients with interstitial nephritis or systemic vasculitis with crescentic nephritis, but was also observed in biopsies with minimal change, IgA or lupus nephropathy, or from patients with diabetic nephropathy, amyloid, or gout. Proximal tubule VCAM-1 correlated significantly with the number of transferrin-receptor-positive leukocytes (r = 0.607, p less than 0.0001) in the interstitium, but not with expression of HLA-DR by tubular cells. Surprisingly, VCAM-1 was not observed on vascular endothelial cells in these biopsies, even in the presence of a marked infiltrate; this contrasts with other tissues (e.g. skin and synovium). The presence of VCAM-1 on tubular cells in the inflamed kidney indicates the potential for these cells to interact with mononuclear cells, either as accessory cells or as cytotoxic targets. The unexpected absence of VCAM-1 in renal vascular endothelial cells suggests local differences in the endothelial cells of this organ.

Antilymphoblast globulin, cyclosporine, and steroids in cadaveric renal transplantation

In order to avoid cyclosporine (CsA) nephrotoxicity and rejection, especially during the early posttransplant periods, different immunosuppression regimens have been adopted. A prospective trial was conducted to evaluate the benefits of initially low CsA doses associated with antilymphoblast globulin and steroids in the first days after transplant, in comparison with higher doses of CsA and steroids. Between 1/86 and 1/88, two groups of first-cadaver renal transplant recipients were documented based on the immunosuppression regimen used. In group A (n = 50), oral CsA was started at 8 mg/kg/day and subsequent doses adjusted to maintain CsA whole-blood levels between 300 and 600 ng/ml. Horse ALG at 10 mg/kg was given the day after transplant and on alternate days to a maximum of 6 doses. After 3 doses, ALG was stopped if CsA blood levels were equal to or greater than 400 ng/ml. ALG dosage modifications were made in order to maintain peripheral CD3+ cells between 10 and 20%. Prednisone was given at 0.25 mg/kg/day. In group B (n = 50), oral CsA was started at 15 mg/kg/day. The CsA whole-blood levels were maintained between 300 and 800 ng/ml. Prednisone was administered at 0.5 mg/kg/day. The incidence of postransplant renal failure was the same in both groups (16%), but the duration of oliguria was lower in group A than in group B (3.3 +/- 2 vs. 16.2 +/- 10.7 days, P less than 0.05), as well as the incidence of acute rejection during the first 3 months (18% vs. 40%, P = 0.01. The cumulative doses of CsA and steroids were significantly lower in group A than in group B. Mean serum creatinine at 6 and 12 months remained similar in both groups. There was no difference between the 2 groups in the incidence of infection. There was no mortality in either group. The actuarial graft survival was significantly higher in group A than in group B at one (100% vs. 94%), two (97% vs. 87%), and three years (89% vs. 73%), respectively (P = 0.041). In summary, the triple regimen using simultaneously low-dose CsA, ALG, and steroids minimizes early graft dysfunction, provides efficient immunosuppression without severe infections, and gives good long-term patient and graft survival.

Lupus nephritis: correlation of interstitial cells with glomerular function

Mononuclear inflammatory cells were studied using monoclonal antibodies in the interstitium and glomeruli of 35 renal biopsy specimens from patients with lupus nephritis already taking immunosuppressants. The aims of this study were to assess the composition and significance of the infiltrate, and to assess correlations with immediate glomerular function and ability to predict the future course of the disease. The majority of interstitial cells were T lymphocytes and monocytes/macrophages. The number of interstitial CD4 + ve T helper/inducer lymphocytes was greater than that of CD8 + ve T cytotoxic/suppressor cells in only 19 out of 35 biopsies, the mean CD4:CD8 ratio being only 1.5 +/- 1.2. NK cells and B lymphocytes were a minor component only. Some expression of IL-2, transferrin and C3b receptors was seen on interstitial cells, but HLA-DR expressing cells were much in excess of controls and the numbers of tubular cells expressing HLA-DR was also increased. The number of interstitial T cells, CD4 + ve cells and monocytes/macrophages was highly correlated with the extent of chronic damage judged by optical microscopy. There was also an association between glomerular function at biopsy and numbers of interstitial T cells, CD8 + ve cells, monocytes/macrophages and DR expressing cells. Subsequent decline in renal function, however, was associated only with numbers of monocytes/macrophages and the rather small number of C3b receptor-positive cells. The presence of tubulointerstitial immune aggregates of Ig and/or C in 63% of patients was associated with greater numbers of NK cells. As previously described, the degree of renal function at biopsy correlated with a chronicity index based on optical microscopy. No correlations were found between numbers or types (mostly monocyte/macrophages) of intraglomerular leukocytes and clinical or biopsy features, except that more proliferative types showed greater leukocyte numbers. One hypothesis consistent with our findings is that interstitial T cells and monocytes may be important determinants of pathogenesis and progression of lupus nephritis. While several mechanisms may play an initial role, interstitial monocytes may be the major factor in chronic injury.

The relevance of induced class II HLA antigens and macrophage infiltration in early renal allograft biopsies

Using a panel of monoclonal antibodies, immunohistological analysis was performed on frozen sections taken from 14 peritransplant renal biopsies and 42 biopsies taken 6 +/- 2 days posttransplantation. The following parameters were examined: tubular expression of HLA-DR, DP, and DQ and infiltration with T lymphocytes and macrophages. Of the 42 posttransplant biopsies, 26 were diagnosed as rejecting and 16 as nonrejecting according to clinical and histopathological criteria. HLA-DR antigens were strongly expressed on 8 of 14 peritransplant biopsies, 23 of 26 rejecting biopsies and 13 of 16 nonrejecting biopsies. Tubular expression of HLA-DP and DQ was weak or absent. In the rejecting biopsies there was a significantly increased infiltrate of T lymphocytes of all phenotypes and of macrophages when compared with the nonrejecting biopsies. Graft outcome was invariably favorable in the nonrejecting group, with no graft losses in the first posttransplant year. There were 4 graft losses in the rejecting group, all due to rejection, and further analysis revealed that all 4 had macrophage-dominated infiltrates in their early allograft biopsies. We conclude that immunohistological analysis of early allograft biopsies provides an accurate prognosis of subsequent graft acceptance or rejection and that early macrophage infiltration is a poor prognostic sign.

Immune mechanisms in idiopathic membranous nephropathy: the role of the interstitial infiltrates

Mononuclear inflammatory cells in renal biopsies from 36 patients with membranous nephropathy (MN) were analyzed, using monoclonal antibodies. In the interstitium, monocytes/macrophages and T cells were the predominant cell types (210 +/- 27 and 171 +/- 25/mm2, respectively); in contrast, very few intraglomerular leucocytes, mostly macrophages (1.0 +/- 0.7 cell/glomerular cross-section), were found. Among the interstitial T-cell population, helper/inducer cells (CD4+) predominated (CD4:CD8 ratio, 2.2 +/- 1.5). Natural killer (NK) cells and B lymphocytes were a minor component of the interstitial infiltrates and were almost absent in the glomeruli. Significantly higher numbers of DR-expressing cells were found in the interstitium (322 +/- 20/mm2) than in controls (109 +/- 30), but tubular DR expression was similar to controls (17 +/- 12 mm2). The numbers of total leukocytes and their subsets CD4+, CD8+, monocytes/macrophages, and B cells all correlated with the degree of renal impairment at the time of biopsy, but surprisingly there was no correlation between interstitial cell numbers and the histological severity of tubulointerstitial lesions. Progressive renal impairment over 5 years was associated with many interstitial T cells and monocytes/macrophages in the initial biopsy. Our results suggest that interstitial mononuclear cells may be important determinants in the pathogenesis of MN. Both cellular and humoral immune mechanisms may play a major role in the initiation of the disease, whereas progression toward renal failure seems to be determined mainly by cell-mediated immunity.

The role of interstitial infiltrates in IgA nephropathy: a study with monoclonal antibodies

The leucocyte subpopulations in the interstitium and the glomeruli in renal biopsies from 34 patients with IgA nephropathy were analysed using monoclonal antibodies and immunoperoxidase techniques. Monocyte/macrophages and T-cells constituted the predominant infiltrating cell type in the interstitium (278 +/- 24 and 269 +/- 37 cells/mm2 respectively). Few intraglomerular leucocytes were seen, the majority of them belonging to the monocyte/macrophage phenotype (1.1 +/- 0.1 cells/glomerular cross-section). CD4+ lymphocytes predominated among the interstitial and glomerular T-cell populations and the CD4:CD8 ratio was 2.1 +/- 1.1 and 2.4 +/- 1.5 respectively. Only small numbers of NK cells and B cells were found in the interstitium, and almost none in the glomeruli. In contrast, significantly increased numbers of DR-expressing interstitial cells were seen (487 +/- 29/mm2), whereas DR expression by the tubular cells was minimal (37 +/- 6/mm2). Numbers of total leukocytes and T-cells were well correlated with the degree of tubulointerstitial damage and there was a significant correlation between renal functional impairment at the time of biopsy and the numbers of interstitial T cells (P less than 0.05) and CD4+ T cells (P less than 0.01). In contrast, interstitial mononuclear cells did not correlate with subsequent progression of the disease over 2-3 years. However, a more rapid decline of renal function was associated with increased numbers of interstitial B cells. No association was found between intraglomerular cells and degree of renal impairment either at the time of biopsy or in the long term.(ABSTRACT TRUNCATED AT 250 WORDS)