Proteinuria and nephrotic syndrome associated with chronic rejection of kidney transplants

Consequences of Nephrotic Proteinuria and Nephrotic Syndrome after Kidney Transplant

Proteinuria is the main predictor of kidney graft loss. However, there is little information regarding the consequences of nephrotic proteinuria (NP) and nephrotic syndrome (NS) after a kidney transplant. We aimed to describe the clinical and histopathological characteristics of kidney recipients with nephrotic-range proteinuria and compare the graft surveillance between those who developed NS and those who did not. A total of 204 patients (18.6% of kidney transplants in the study period) developed NP, and 68.1% of them had NS. Of the 110 patients who underwent a graft biopsy, 47.3% exhibited ABMR, 21.8% the recurrence of glomerulonephritis, 9.1% IFTA, and 7.3% de novo glomerulonephritis. After a median follow-up of 97.5 months, 64.1% experienced graft loss. The graft survival after the onset of NP declined from 75.8% at 12 months to 38% at 5 years, without significant differences between those with and those without NS. Patients who developed NS fewer than 3 months after the onset of NP exhibited a significantly higher risk of death-censored graft loss (HR: 1.711, 95% CI: 1.147-2.553) than those without NS or those with late NS. In conclusion, NP and NS are frequent conditions after a kidney transplant, and they imply extremely poor graft outcomes. The time from the onset of NP to the development of NS is related to graft survival.

Chronic renal allograft damage after transplantation: what are the reasons, what can we do?

PURPOSE OF REVIEW

Chronic renal allograft damage is one of the main problems after kidney transplantation. This review enumerates causes, describes available therapeutic options, and discusses options of the future.

RECENT FINDINGS

Alloantigen-dependent and alloantigen-independent factors are responsible for allograft damage. Prevention of renal allograft damage starts with interventions that occur surrounding the explantation in cadaveric organs. These include the use of dopamine or machine perfusion systems.Followed by the critical phase of ischemia/reperfusion injury, the LCN2/lipocalin-2, HAVCR1, and p38 MAPK pathway are new players involved in that process. Innate immunity plays a part, too. Cold ischemia time is associated with genes of apoptosis. Nondonor-specific antibodies like antihuman leukocyte antibodies-Ia or angiotensin type 1 receptor may also play a role. Recent research indicates that genetic polymorphism like the Ficolin-2 Ala258Ser polymorphism and the mannose-binding lectin-2 polymorphism are involved in that process. New therapeutic options are rare and in the future. However, there is some evidence that drugs interfering with metalloproteinases, sexual hormones like dihydroandrosterone, and mesenchymal stem cell therapy may be of importance.

SUMMARY

Taken together, although the understanding of chronic rejection has improved, the available therapeutic options remain scarce.

Animal models of chronic allograft injury: contributions and limitations to understanding the mechanism of long-term graft dysfunction

Advances in immunosuppression have reduced the incidence of acute graft loss after transplantation, but long-term allograft survival is still hindered by the development of chronic allograft injury, a multifactorial process that involves both immunologic and nonimmunologic components. Because these components become defined in the clinical setting, development of animal models enables exploration into underlying mechanisms leading to long-term graft dysfunction. This review presents animal models that have enabled investigation into chronic allograft injury and discusses pivotal models currently being used. The mechanisms uncovered by these models will ultimately lead to development of new therapeutic options to prevent long-term graft dysfunction.

The urinary excretion of ten plasma proteins in long-term renal transplant patients

Using an automated immunoprecipitin reaction, the urinary excretion of albumin, transferrin, haptoglobin, IgM, IgG, IgA, free lambda and kappa light chains from immunoglobulin, lysozyme and beta2-microglobulin has been investigated in 40 long-term bilaterally nephrectomized renal transplant patients. The excretion of the proteins, except lysozyme, was significantly increased in 21 of the paitents with Albustix-negative urine. In patients with glomerulonephritis prior to the transplantation, the excretion of albumin, transferrin, and IgG was significantly increased compared with the other patients. The IgM excretion was significantly increased in patients who had received C and D matches compared with those with A and B matches. Patients with severe surgical complications in the postoperative period had a tubular proteinuria, and in patients surviving more than 60 months after transplantation the excretion of several proteins was significantly increased compared with patients surviving less than 60 months.

Altered kidney graft high-energy phosphate metabolism in kidney-transplanted end-stage renal disease type 1 diabetic patients: a cross-sectional analysis of the effect of kidney alone and kidney-pancreas transplantation

OBJECTIVE

Diabetes, hypertension, dyslipidemia, obesity, nephrotoxicity of certain immunosuppressive drugs, and the persistence of a chronic alloimmune response may significantly affect graft survival in end-stage renal disease (ESRD) type 1 diabetic patients who have undergone kidney transplant. The aim of this study was to ascertain the impact of kidney alone (KD) or combined kidney-pancreas (KP) transplantation on renal energy metabolism.

RESEARCH DESIGN AND METHODS

We assessed high-energy phosphates (HEPs) metabolism by using, in a cross-sectional fashion, 31P-magnetic resonance spectroscopy in the graft of ESRD type 1 diabetic transplanted patients who received KD (n = 20) or KP (n = 20) transplant long before the appearance of overt chronic allograft nephropathy (CAN). Ten nondiabetic microalbuminuric kidney transplanted patients and 10 nondiabetic kidney transplanted patients with overt CAN were chosen as controls subjects.

RESULTS

Simultaneous KP transplantation patients showed a higher beta-ATP/inorganic phosphorus (Pi) ratio (marker of the graft energy status) versus the other groups, and a positive correlation between beta-ATP/Pi phosphorus ratio and A1C was found. In the analysis limited to the subgroup of normoalbuminuric patients, the difference in beta-ATP/Pi was still detectable in KP patients compared with KD transplantation.

CONCLUSIONS

KP transplantation was associated with better HEPs than in KD transplantation, suggesting that restoration of beta-cell function positively affects kidney graft metabolism.

Call for revolution: a new approach to describing allograft deterioration

I propose a set of definable entities in the renal transplant course, eliminating the need for the term 'chronic rejection'. The status of a renal transplant can be defined by the presence and extent of rejection (T-cell-mediated or antibody-mediated); allograft nephropathy (parenchymal atrophy, fibrosis, and fibrous intimal thickening in arteries); transplant glomerulopathy; specific diseases; and factors which could accelerate progression. The level of function and the slope of the loss of function should be separately determined. This approach can be applied both in research and in clinical practice, and can be adapted to other organ transplants.

Acute rejection presenting as nephrotic syndrome

BACKGROUND

Early diagnosis and treatment of acute rejection is important to prevent continued renal injury. Acute rejection most commonly presents with asymptomatic rise in serum creatinine. Proteinuria associated with acute rejection is well established; however, there is limited documentation of the presentation of acute rejection as nephrotic syndrome in the literature.

METHODS AND RESULTS

We report a renal transplant patient who presented with early onset nephrotic syndrome without change in serum creatinine, whose allograft biopsy confirmed acute glomerulitis and vascular rejection. Treatment of the acute rejection was accompanied by resolution of the nephrotic syndrome. A second episode of acute rejection was also manifested as nephrotic range proteinuria.

CONCLUSION

The nephrotic syndrome in early post-transplantation period should prompt a work-up for acute rejection even in the absence of the common findings of this complication.

Durable donor-specific T and B cell tolerance in rhesus macaques induced with peritransplantation anti-CD3 immunotoxin and deoxyspergualin: absence of chronic allograft nephropathy

Tolerance induction can prevent acute kidney allograft rejection without chronic immunosuppression. It is uncertain whether specific tolerance can prevent chronic allograft nephropathy (CAN), which involves both nonimmune and immune injury. This report provides evidence that immunologically tolerant macaques, induced with immunotoxin and deoxyspergualin, developed neither acute rejection nor CAN. Long survivors, bearing MHC-mismatched grafts without chronic immunosuppression for 0.8 to 3.4 years, exhibited general immune competence with donor-specific T and B cell tolerance and no functional or histological evidence of CAN. Stringent criteria for tolerance were satisfied by specific prolongation of donor skin grafts with rapid rejection of third-party skin, followed by indefinite acceptance of a second donor kidney graft and establishment of microchimerism. Primate tolerance with documented absence of CAN may give impetus to the clinical application of tolerance.

Chronic renal allograft rejection: immunologic and nonimmunologic risk factors

The pathogenesis of chronic renal allograft rejection is unknown. It is also unclear why cyclosporine has failed to prevent chronic rejection. We examined possible risk factors for graft loss to chronic rejection among 706 renal transplants using the Cox proportional hazards model with fixed and time-dependent covariates. Both the number and the severity of acute rejection episodes were independent risk factors for chronic rejection [relative risk (95% confidence interval) 2.31 (2.04 to 2.60) and 1.53 (1.27 to 1.84), respectively]. Cyclosporine and cyclosporine withdrawal had no effect on chronic rejection. Acute rejections occurring within the first three months after transplantation, when cyclosporine most effectively prevented acute rejection, also had no effect on chronic rejection. Risk factors that were independent of acute rejection and not clearly attributable to immune mechanisms included serum albumin [0.20 (0.10 to 0.38) for each g/dl], proteinuria [1.42 (1.29 to 1.57) for each g/24 hr], and serum triglycerides -1.09 (1.03 to 1.16) for each 100 mg/dl-. These results suggest that the reduction in acute rejection episodes from cyclosporine has failed to reduce graft failure from chronic rejection, possibly because the early (within the first 3 months) and mild acute rejection episodes that are most effectively prevented by cyclosporine do not cause chronic rejection. In addition, the results suggest that there may be a number of nonimmunologic risk factors for chronic rejection.

Glomerular permselectivity in proteinuric patients after kidney transplantation

To characterize the defect in glomerular permselectivity responsible for proteinuria after renal transplantation, we studied 10 patients with moderate proteinuria (median 0.37 g/d, range 0.20-0.79), 16 patients with the nephrotic syndrome (6.73 g/d, 3.9-14.6), 8 living related donor transplant recipients without any history of rejection (median proteinuria 0.26 g/d, 0.06-0.58), and 12 healthy volunteers. The fractional clearance of neutral dextrans > 54 A was significantly higher in nephrotic patients, demonstrating a defect in glomerular size selectivity. Using a log-normal model of glomerular pore size distribution, r*(5%) and r*(1%), indices for the presence of large pores, were increased in the nephrotic patients. The fractional clearance of negatively charged dextran sulfate was significantly higher in all patient groups, indicating a loss of glomerular charge selectivity. Biopsy findings showed more prominent glomerular lesions in the nephrotic group compared with the moderately proteinuric group. We conclude that mild proteinuria late after renal transplantation is associated with a defect in glomerular charge selectivity. The development of nephrotic range proteinuria is associated also with a defect of glomerular size selectivity, which correlates with prominent glomerular pathology.

Mechanism, pathophysiology, diagnosis, and management of renal transplant rejection

In recent years, there has been a steady progress in basic research (immunogenetics and cellular immunology) that helped us in understanding the mechanisms underlying allograft rejection. Several laboratory tests were developed, and the results were shown to correlate with clinical rejection. However, most of these studies have not found a place in clinical practice because of their nonspecificity, lack of sensitivity, time lag, added expense, and inconvenience. The commonly employed diagnostic tests (i.e., renal transplant ultrasound and 131I hippuran scintigram) are helpful in differentiating rejection from other causes of graft malfunction. The specific renal parenchymal disease, such as acute or chronic rejection or de novo or recurrent glomerular disease, contributing to graft malfunction can only be diagnosed by renal histopathologic study. Because hyperacute and accelerated acute rejections are irreversible and necessitate graft nephrectomy, measures should be taken to prevent this problem. High-dose corticosteroids still remain the mainstay of therapy for acute cellular rejection. In the case of steroid-resistant rejections, treatment with ALG or OKT3 appears promising. As there is no effective therapy for chronic allograft rejection, usual measures of delaying the progression of chronic renal failure should be employed, and patients should be advised to return to maintenance dialysis before they develop uremic symptoms. If current experiments demonstrating selective immunosuppression with monoclonal antibodies are found successful in human trials, one can expect further improvement in the outcome of renal transplantation.

Nephrotic range proteinuria with "minimal change glomerulopathy" in human renal allografts: report of four cases

Four patients who received renal allografts developed nephrotic range proteinuria 2 to 16 months after renal transplantation. Twenty-four-hour urine protein excretion at the time of renal allograft biopsy ranged from 5.9 to 17.0 g/24 hours. The serum creatinine at the time of renal allograft biopsy ranged from 2.0 to 3.9 mg/dl (180 to 350 mumol/L). Biopsies of the allografts demonstrated minimal glomerular abnormalities by light microscopy, immunomicroscopy, and electron microscopy. Two biopsies exhibited severe interstitial fibrosis. These four cases illustrate the unusual finding of "minimal change glomerulopathy" in renal allograft recipients exhibiting nephrotic range proteinuria. All four patients progressed to dialysis 4, 36, 46, and 53 months after transplantation. Transplant nephrectomy was performed in three patients. One showed acute cortical necrosis. Two showed glomerular, vascular, and tubular-interstitial features of chronic rejection.

An ultrastructural study of the membranoproliferative variant of transplant glomerulopathy

In this study we analyzed the ultrastructural features of the membranoproliferative variant of transplant glomerulopathy in 6 patients from a group of 64 renal transplant recipients who had evidenced graft dysfunction and histological diagnosis of chronic allograft rejection. The principle changes observed by electron microscopy were thickening of glomerular basement membranes by polymorphous changes that included widening of the lamina rara interna by an electron lucent material resembling plasma constituents, replication of lamina densa-like material, and inclusion of microfilaments, membranous profiles, and other cellular remnants. Proliferation of endothelial cells was a prominent finding, suggesting that a reparative endothelial response to injury may be significant to the pathogenesis of this form of transplant glomerulopathy.

Urinary protein/creatinine ratio as an indicator of allograft function following live related donor renal transplantation

In a study of 656 urine specimens from 53 consecutive recipients of live related donor renal allografts we found an excellent correlation between the protein content of 24-h urines and protein/creatinine ratio (Up/Ucr) in overnight urine samples. Using this ratio, we evaluated proteinuria up to 180 days after renal transplantation (overnight urine samples analysed, n = 2745). Heavy proteinuria in the immediate post-operative period had no prognostic significance. Eighty-nine percent of all clinically observed acute rejection episodes were accompanied by an increase over baseline of Up/Ucr; in 56.5% of these episodes elevation of Up/Ucr preceded that of serum creatinine. However, as a marker of rejection the usefulness of this parameter was limited owing to large number of false positive elevations. In 50 recipients whose grafts survived for more than 3 mth, proteinuria was graded into minimal, moderate and heavy. Renal function at the end of six months was good in all patients who exhibited proteinuria with Up/Ucr less than 100 mg/mmol creatinine. Persistent proteinuria with Up/Ucr above 100 mg/mmol preceded significant deterioration of graft function. Therefore, a protein-creatinine ratio of 100 mg/mmol can be considered as an apparent cut-off to differentiate stable from deteriorating graft function in long term evaluation of transplant recipients.

Status of renal transplantation. A clinical perspective

Although the survival of patients on chronic dialysis has improved in recent years, the quality and status of rehabilitation remains poor. Renal transplantation must be used to complement chronic dialysis in the management of these patients. Physicians should not be biased and commit their patients to one or the other form of long-term treatment.

Kidney transplant nephrotic syndrome: relationship between allograft histopathology and natural course

We analyzed clinical and pathologic data from 36 recipients of 38 renal allografts who developed nephrotic syndrome following transplantation. Three groups were identified on the basis of histologic changes in the graft, and each group had a distinct clinical course. Nine grafts (23.7%) had recurrent glomerulonephritis (GN) (5 membrano-proliferative, 4 focal glomerulosclerosis) and developed nephrotic syndrome at 5.1 months (mean) posttransplant. Renal function deteriorated rapidly, with a 2-year graft survival of 29.7%. Four grafts (10.5%) with de novo GN (3 epimembranous, 1 minimal change) developed nephrotic syndrome at 32 months posttransplant, and all functioned for more than 3 years. Twenty-five grafts (65.8%) had allograft glomerulopathy with the onset of nephrotic syndrome at 9.1 months posttransplant and a 2-year graft survival of 66.6%. The differences in duratin of graft function between grafts with allograft glomerulopathy and recurrent GN (P < 0.01) and in graft survival rates at 2 years among the three groups (P < 0.05) are statistically significant. This analysis indicates that allograft glomerulopathy is the most common cause of kidney transplant nephrotic syndrome. Membranoproliferative GN and focal glomerulosclerosis may recur soon after transplantation and rapidly progress to renal failure in marked contrast to grafts with either de novo epimembranous nephropathy or minimal glomerular change, lesions that are compatible with prolonged graft function.

Focal glomerulosclerosis and renal transplantation

Eighteen patients with corticosteroid-resistant nephrotic syndrome developed end-stage renal disease and received one or more renal allografts. The lesion of focal segmental glomerulosclerosis and/or of focal glomerular obsolescence was demonstrable in the native kidneys of each patient. Following transplantation, nephrosis developed in three recipients. Two recipients developed nephrosis at two weeks and nine months posttransplant in association with rejection; the lesion of FGS was present in association with chronic rejection. Only one recipient developed recurrence of nephrosis and FGS unrelated to rejection. This was manifested by immediate onset of nephrosis in two successive allografts and histologic evidence of the lesion of FGS. The immediate recurrence in successive allografts suggests a circulating factor responsible for the renal lesion in this patient and indicates a separate etiology for a small number of patients with corticosteroid-resistant nephrosis and FGS.

[Protein concentration in the urine of normal subjects]

A fim de determinar os valores normais de concentração proteica na urina, em amostra de população sadia, foi usada uma reação de biureto, em 62 amostras de urina coletadas ao acaso. A concentração proteica média em todo o grupo foi de 6,0mg% (± 3,2) com a amplitude de 2,0 - 14,5mg%. Tais resultados concordam com aqueles previamente relatados na literatura.

Effect of rabbit ALG on cadaver kidney transplant survival

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Renal transplantation in children. Analysis of 25 consecutive transplants in 19 recipients

Eighteen children aged 6 to 17 years received 24 cadaveric renal transplants between January 1965 and July 1971, and a further child received a kidney donated by her father. 12 children are alive with good functioning grafts and another 2 children are alive on haemodialysis awaiting a further renal graft. The clinical problems of renal transplantation in children are discussed with particular reference to the side effects of immunosuppressive therapy.

Renal allograft with massive perirenal accumulation of lymph

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