Impact of Pregnancy on GFR Decline and Kidney Histology in Kidney Transplant Recipients

Introduction

Women with advanced kidney disease are advised to wait until after transplant to pursue pregnancy, but the impact of pregnancy on estimated glomerular filtration rate (eGFR) decline and kidney histology is unclear.

Methods

We identified a cohort of women aged 18 to 44 years at transplant from 1996 to 2014 at our 3-site program (N = 816) and determined whether they had a pregnancy >20 weeks gestation post-transplant by chart review. Outcomes included rate of change in eGFR after pregnancy, changes in kidney histology before and after pregnancy, graft failure, and 50% reduction in eGFR.

Results

There were 37 women with one or more pregnancies lasting longer than 20 weeks gestation post-transplant. Comparing women with and without pregnancy post-transplant, there was a significant increase in the rate of eGFR decline after pregnancy (−2.4 ml/min per 1.73 m² per year vs. −1.9 ml/min per 1.73 m² per year in women with no pregnancy, P < 0.001). Pregnancy did not affect the risk of graft failure, death-censored graft failure, or 50% reduction in eGFR.

Conclusion

Pregnancy affects the rate of eGFR decline in the allograft. Postpregnancy biopsy findings revealed an increase in vascular injury, which could be a potential mechanism. We did not find a significant increase in risk of graft failure or reduction in eGFR by 50% owing to pregnancy.

Pregnancy, Contraception, and Menopause in Advanced Chronic Kidney Disease and Kidney Transplant

Background: Reproductive health is an essential part of the care of women with kidney disease. However, the self-reported patient experience of reproductive issues has been underexplored.

Materials and Methods: We identified a cohort of women ages 18 to 44 at the time of kidney transplant from 1996 to 2014 at our 3-site program (n = 816). We sent each woman a survey on her reproductive lifespan, characterizing features from menarche to menopause.

Results: We received survey responses from 190 patients (27%). One third of respondents reported amenorrhea before transplant, and 61.5% of these women reported resumption of menses post-transplant. The average age of menopause was 45.5 years, earlier than the general population (51.3 years). There were 204 pregnancies pretransplant and 52 pregnancies post-transplant. Pregnancies post-transplant were more likely to be complicated by preeclampsia, preterm delivery, and small for gestational age babies than pregnancies that occurred >5 years before transplant. Pregnancies <5 years before transplant were similar to post-transplant pregnancies with respect to complications. Forty-two percent of women were advised to avoid pregnancy after transplant, most often by a nephrology provider.

Conclusions: In our cohort of kidney transplant recipients, women report increased pregnancy-related complications post-transplant and in the 5 years before transplant, compared with pregnancies that occurred greater than 5 years before transplant. They were often counseled to avoid pregnancy altogether. Women reported a younger age of menopause relative to the general population. This should be considered when counseling patients with chronic kidney disease regarding optimal pregnancy timing.

Long-term Outcomes of Sequential Hematopoietic Stem Cell Transplantation and Kidney Transplantation: Single-center Experience

BACKGROUND

Experience with sequential hematopoietic stem cell transplant (HSCT) and kidney transplant (KT) is limited.

METHODS

We conducted a retrospective observational study of adult patients who underwent both HSCT and KT at our center, with a median follow-up of 11 y.

RESULTS

In our 54 patients cohort (94% autologous HSCT), 36 (67%) patients received HSCT first followed by KT, while 18 (33%) received KT before HSCT. In both groups, AL amyloidosis represented 50% of hematologic diagnosis. Only 4 patients expired due to hematologic disease relapse (2 patients in each group) and only 3 allografts were lost due to hematologic disease recurrence (HSCT first n = 1 and KT first n = 2). Overall 1, 5, and 10 y death-censored graft survival rates were 94%, 94%, and 94%, respectively, for the HSCT first group and 89%, 89%, and 75%, respectively, for the KT first group. Overall 1, 5, and 10 y patients survival rates were 100%, 97% and 90%, respectively, for the HSCT first group and 100%, 76%, and 63%, respectively, for the KT first group.

CONCLUSIONS

Our study supports safety of sequential KT and HSCT, with improved overall patient survival compared to recipients of HSCT remaining on dialysis and good long-term kidney allograft outcome.

Recurrence of DNAJB9-Positive Fibrillary Glomerulonephritis After Kidney Transplantation: A Case Series

RATIONALE & OBJECTIVE

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease that often progresses to kidney failure requiring kidney replacement therapy. We have recently identified a novel biomarker of FGN, DnaJ homolog subfamily B member 9 (DNAJB9). In this study, we used sequential protocol allograft biopsies and DNAJB9 staining to help characterize a series of patients with native kidney FGN who underwent kidney transplantation.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

Between 1996 and 2016, kidney transplantation was performed on 19 patients with a reported diagnosis of FGN in their native/transplant kidneys. Using standard diagnostic criteria and DNAJB9 staining, we excluded 5 patients (4 atypical cases diagnosed as possible FGN and 1 donor-derived FGN). Protocol allograft biopsies had been performed at 4, 12, 24, 60, and 120 months posttransplantation. DNAJB9 immunohistochemistry was performed using an anti-DNAJB9 rabbit polyclonal antibody. Pre- and posttransplantation demographic and clinical characteristics were collected. Summary statistical analysis was performed, including nonparametric statistical tests.

OBSERVATIONS

The 14 patients with FGN had a median posttransplantation follow-up of 5.7 (IQR, 2.9-13.8) years. 3 (21%) patients had recurrence of FGN, detected on the 5- (n=1) and 10-year (n=2) allograft biopsies. Median time to recurrence was 10.2 (IQR, 5-10.5) years. Median levels of proteinuria and iothalamate clearance at the time of recurrence were 243mg/d and 56mL/min. The remaining 11 patients had no evidence of histologic recurrence on the last posttransplantation biopsy, although the median time of follow-up was significantly less at 4.4 (IQR, 2.9-14.4) years. 3 (21%) patients had a monoclonal protein detectable in serum obtained pretransplantation; none of these patients had recurrent FGN.

LIMITATIONS

Small study sample and shorter follow-up time in the nonrecurrent versus recurrent group.

CONCLUSIONS

In this series, FGN had an indolent course in the kidney allograft in that detectable histologic recurrence did not appear for at least 5 years posttransplantation.

De novo pauci-immune glomerulonephritis in renal allografts

Pauci-immune glomerulonephritis in the native kidney presents with renal insufficiency, proteinuria, and hematuria, and is usually due to anti-neutrophil cytoplasmic antibodies. Rarely, kidney transplants can show this pattern as de novo disease. We performed a retrospective analysis in 10 cases of de novo pauci-immune glomerulonephritis. The mean time from transplant to diagnostic biopsy was 32 months (range, 4-96). All biopsies showed focal necrotizing or crescentic glomerulonephritis (mean 16% glomeruli, range 2-36%). Immunofluorescence and electron microscopy showed a pauci-immune pattern. No patients had evidence of systemic vasculitis. Anti-neutrophil cytoplasmic antibody results were available for 7 patients and were negative in all but one. Most patients had functioning grafts at one year after diagnosis. Two patients had repeat biopsies that showed continued active glomerulonephritis. We report the first clinicopathologic series of de novo pauci-immune glomerulonephritis which appears to be a unique pathologic entity that may occur early or late post-transplant and in our cohort is not associated with systemic vasculitis and usually not associated with anti-neutrophil cytoplasmic antibodies. The degree of crescent formation and renal impairment are milder than those of pauci-immune crescentic glomerulonephritis in the native kidney.

Using computer-assisted morphometrics of 5-year biopsies to identify biomarkers of late renal allograft loss

The current Banff scoring system was not developed to predict graft loss and may not be ideal for use in clinical trials aimed at improving allograft survival. We hypothesized that scoring histologic features of digitized renal allograft biopsies using a continuous, more objective, computer-assisted morphometric (CAM) system might be more predictive of graft loss. We performed a nested case-control study in kidney transplant recipients with a surveillance biopsy obtained 5 years after transplantation. Patients that developed death-censored graft loss (n = 67) were 2:1 matched on age, gender, and follow-up time to controls with surviving grafts (n = 134). The risk of graft loss was compared between CAM-based models vs a model based on Banff scores. Both Banff and CAM identified chronic lesions associated with graft loss (chronic glomerulopathy, arteriolar hyalinosis, and mesangial expansion). However, the CAM-based models predicted graft loss better than the Banff-based model, both overall (c-statistic 0.754 vs 0.705, P < .001), and in biopsies without chronic glomerulopathy (c-statistic 0.738 vs 0.661, P < .001) where it identified more features predictive of graft loss (% luminal stenosis and % mesangial expansion). Using 5-year renal allograft surveillance biopsies, CAM-based models predict graft loss better than Banff models and might be developed into biomarkers for future clinical trials.

The Relationship Between Frailty and Decreased Physical Performance With Death on the Kidney Transplant Waiting List

INTRODUCTION

Frailty and decreased physical performance are associated with poor outcomes after kidney transplant. Less is known about their relationship with pretransplant outcomes. The aim of this study was to characterize associations between frailty and physical performance with death on the kidney transplant waiting list.

DESIGN

Since December 2014, high-risk kidney transplant candidates at our center (age > 59, diabetic and/or history of >3 years dialysis) have undergone frailty and physical performance testing using Fried Criteria and the Short Physical Performance Battery.

RESULTS

Between December 2014 and November 2016, 272 high-risk candidates underwent testing and were approved for transplant. Both frailty and physical performance score were significantly associated with death on the waiting list (hazard ratio [HR]: 6.7, confidence interval [CI]: 1.5-30.1; P = .01; HR: 0.8 per 1-point increase, CI: 0.7-1.0; P = .02, respectively). The relationship between frailty, physical performance score, and death on the waiting list appeared to be independent of age, diabetes, or duration of dialysis.

DISCUSSION

Frailty and decreased physical performance appear to be independently associated with increased mortality on the kidney transplant waiting list. Further studies are needed to determine whether improving frailty and physical performance prior to transplant can decrease waiting list mortality.

Karyomegalic interstitial nephritis in a renal allograft

Karyomegalic interstitial nephritis (KIN) is a rare renal interstitial disease entity characterized by large tubular nuclei, accompanied by interstitial inflammation, tubular atrophy, and interstitial fibrosis. Approximately 50 cases of KIN have been described in the native kidney. In this case study, we describe the first case of KIN in a kidney allograft. A 41-year-old man presented with declining kidney function and a serum creatinine of 2.7 mg/dL. The native kidney biopsy showed large pleomorphic nuclei in the proximal and distal tubular epithelial cells, which was associated with interstitial inflammation, and extensive interstitial fibrosis and tubular atrophy. Immunohistochemistry for cytomegalovirus, adenovirus, and simian virus 40 were negative. A diagnosis of KIN was rendered. The patient received a living-related kidney transplant from his sister. At 4-, 12-, and 24-months posttransplant, protocol allograft biopsies showed KIN with large pleomorphic nuclei in the proximal and distal tubules with mild interstitial inflammation, minimal tubular atrophy, and interstitial fibrosis. At 24.7 months of follow-up, the patient has stable renal function with a serum creatinine of 1.6 mg/dL. The KIN may represent recurrent KIN or donor-associated KIN. Recognition of this rare disease entity is important as it can be mistaken for a viral infection.

Late graft failure after kidney transplantation as the consequence of late versus early events

Beyond the first posttransplant year, 3% of kidney transplants fail annually. In a prospective, multicenter cohort study, we tested the relative impact of early versus late events on risk of long-term death-censored graft failure (DCGF). In grafts surviving at least 90 days, early events (acute rejection [AR] and delayed graft function [DGF] before day 90) were recorded; serum creatinine (Cr) at day 90 was defined as baseline. Thereafter, a 25% rise in serum Cr or new-onset proteinuria triggered graft biopsy (index biopsy, IBx), allowing comparison of risk of DCGF associated with early events (AR, DGF, baseline serum Cr >2.0 mg/dL) to that associated with later events (IBx). Among 3678 patients followed for 4.7 ± 1.9 years, 753 (20%) had IBx at a median of 15.3 months posttransplant. Early AR (HR = 1.77, P < .001) and elevated Cr at Day 90 (HR = 2.56, P < .0001) were associated with increased risk of DCGF; however, later-onset dysfunction requiring IBx had far greater impact (HR = 13.8, P < .0001). At 90 days, neither clinical characteristics nor early events distinguished those who subsequently did or did not undergo IBx or suffer DCGF. To improve long-term kidney allograft survival, management paradigms should promote prompt diagnosis and treatment of both early and later events.

De novo donor-specific antibody following BK nephropathy: The incidence and association with antibody-mediated rejection

BACKGROUND AND OBJECTIVES

The risk of de novo donor-specific antibody (dnDSA) development following BK viremia (BKV) or nephropathy (BKN) after kidney transplant remains unclear. We aimed to evaluate the relationships among dnDSA, BKV (BK blood PCR > 15 000 copies), BKN, antibody-mediated rejection (AMR), and allograft loss.

PATIENTS AND METHODS

We performed a retrospective cohort study of 904 solitary kidney transplant recipients transplanted between 10/2007 and 5/2014. Cox proportional hazards regression with time-dependent covariates were used to assess the relationships among BKN, isolated BKV, dnDSA, and the subsequent risk of AMR and allograft loss.

RESULTS

In multivariate analysis, we observed that BKN, but not BKV was a risk factor for dnDSA (HR, 3.18, P = .008). Of the patients with BK nephropathy, 14.0% (6/43) developed dnDSA, which occurred within 14 months of BK diagnosis. DnDSA in this setting remains a risk factor for subsequent AMR (HR 4.75, P = .0001) and allograft loss (HR 2.63, P = .018).

CONCLUSIONS

BKN is an independent risk factor for development of dnDSA. Improved understanding of the characteristics of patients with BKN who are at highest risk for development of dnDSA would be valuable to customize immunosuppression reduction in this population.

Renal Allograft Histology at 10 Years After Transplantation in the Tacrolimus Era: Evidence of Pervasive Chronic Injury

Improving long-term renal allograft survival remains an important unmet need. To assess the extent of histologic injury at 10 years after transplantation in functioning grafts, we studied 575 consecutive adult solitary renal transplants performed between 2002 and 2005: 77% from living donors and 81% maintained on tacrolimus-based immunosuppression. Ten-year graft survival was 59% and death-censored graft survival was 74%. Surveillance allograft biopsies were assessed at implantation, 5 years, and 10 years from 145 patients who reached 10 years. At implantation, 5% of biopsies had major histologic abnormalities (chronic transplant glomerulopathy score > 0, other chronic Banff scores ≥ 2, global glomerulosclerosis > 20%, or mesangial sclerosis ≥ 2). This increased to 54% at 5 years and 82% at 10 years. Major lesions at 10 years included the following: arteriolar hyalinosis (66%), mesangial sclerosis (67%), and global glomerulosclerosis > 20% (43%), with 48% of grafts having more than one major lesion. Transplant glomerulopathy and moderate-to-severe interstitial fibrosis were uncommon (12% each). Major lesions were associated with increased proteinuria and decreased graft function. In patients with diabetes at baseline, 52% had diabetic nephropathy/mesangial sclerosis at 10 years. We conclude that almost all renal allografts sustain major histologic injury by 10 years after transplantation. Much damage appears nonimmunologic, suggesting that new approaches are needed to decrease late injury.

Renal Allograft Outcome After Simultaneous Heart and Kidney Transplantation

Chronic kidney disease frequently accompanies end-stage heart failure and may result in consideration of simultaneous heart and kidney transplantation (SHKT). In recent years, there has been a significant increase in SHKT. This single-center cohort consisted of 35 patients who underwent SHKT during 1996 to 2015. The aim of this study was to review factors that may predict better long-term outcome after SKHT. Thirteen patients (37%) had delayed graft function (DGF) after transplant (defined as the need for dialysis during the first 7 days after transplant), which was significantly associated with mechanical circulatory support device therapy and high right ventricular systolic pressure before transplant. Most of the recipients had glomerular filtration rate (GFR) ≥50 ml/min/1.73 m² at 1 and 3 years after transplant (21 of 26 [81%] and 20 of 21 [95%], respectively). Higher donor age was associated with reduced 1-year GFR (p = 0.017), and higher recipient pretransplant body mass index was associated with reduced 3-year GFR (p = 0.008). There was a significant association between DGF and reduced median GFR at 1 and 3 years after transplant (p <0.005). Patient survival rates at 6 months, 1, and 3 years after transplant were 97%, 91%, and 86% respectively. In conclusions, our data support good outcomes after SHKT. Mechanical circulatory support device therapy and pulmonary hypertension before transplant are associated with DGF, which is a risk factor for poor long-term renal allograft function.

Relationship between pre-transplant physical function and outcomes after kidney transplant

BACKGROUND

Performance-based measures of physical function predict morbidity following non-transplant surgery. Study objectives were to determine whether physical function predicts outcomes after kidney transplant and assess how physical function changes post-transplant.

METHODS

We conducted a prospective study involving living donor kidney transplants recipients at our center from May 2012 to February 2014. Physical function was measured using the Short Physical Performance Battery (SPPB [balance, chair stands, gait speed]) and grip strength testing. Initial length of stay (LOS), 30- day rehospitalizations, allograft function, and quality of life (QOL) were assessed.

RESULTS

The majority of the 140 patients in our cohort had excellent pre-transplant physical function. In general, balance scores were more predictive of post-transplant outcomes than the SPPB. Decreased pre-transplant balance was independently associated with longer LOS and increased rehospitalizations but not with post-transplant QOL; 35% of patients experienced a clinically meaningful (≥ 1.0 m/s) improvement in gait speed 4 months post-transplant.

CONCLUSIONS

Decreased physical function may be associated with longer LOS and rehospitalizations following kidney transplant. Further studies are needed to confirm this association. The lack of relationship between pre-transplant gait speed and outcomes in our cohort may represent a ceiling effect. More comprehensive measures, including balance testing, may be required for risk stratification.

Recent advances in our understanding of recurrent primary glomerulonephritis after kidney transplantation

Recurrent glomerulonephritis (GN) is an important cause of kidney allograft failure, particularly in younger recipients. Approximately 15% of death-censored graft failures are due to recurrent GN, but this incidence is likely an underestimation of the magnitude of the problem. Overall, 18% to 22% of kidney allografts are lost due to GN, either recurrent or presumed de novo. The impact of recurrent GN on allograft survival was recognized from the earliest times in kidney transplantation. However, progress in this area has been slow, and our understanding of GN recurrence remains limited, in large part due to incomplete understanding of the pathogenesis of these diseases. This review focuses on recent advances in our general understanding of the pathophysiology of primary GN, the risk of recurrence in the allograft, and the consequences for kidney graft survival. We focus specifically on the most common forms of primary GN, including focal segmental glomerulosclerosis, membranous nephropathy, membranoproliferative glomerulonephritis, and IgA nephropathy. New understanding of the pathogenesis of these diseases has had direct clinical implications for transplantation, allowing better identification of candidates at high risk of recurrence and earlier diagnoses, and it is expected to lead to significance improvements in the therapy and perhaps even prevention of GN recurrence. More than ever, it is essential to fully characterize GN before transplantation as this information will direct our management posttransplantation. Further, the relative rarity of recurrent GN dictates the need for multicenter studies in order to evaluate, test, and validate recent advances and therapies.

Outcomes of patients with renal monoclonal immunoglobulin deposition disease

Recent reports suggest that deep hematologic responses to chemotherapy are associated with improved renal outcomes in monoclonal immunoglobulin deposition disease (MIDD). Here we describe the long term outcomes and identify prognostic factors after first line treatment of the largest reported series of patients with MIDD. Between March 1992 and December 2014, 88 patients with MIDD were seen at Mayo Clinic, MN. Renal responses were defined using criteria used for light chain amyloidosis (AL) or those used by the IMWG. Sixty-one (69%) patients had a GFR < 30 mL/min/1.73 m² and 16 (18%) were on renal replacement therapy at diagnosis. The interval between albuminuria or elevation in creatinine and MIDD diagnosis was 12 months suggesting a delay in diagnosis. Thirty-seven patients (42%) had at least a hematologic CR/VGPR. Fifty-three (60%) received an autologous stem cell transplant (ASCT) or proteasome inhibitor (PI)-based treatments. Patients receiving ASCT or PI-based therapies were more likely to achieve at least a hematologic CR/VGPR compared to those receiving other therapies: 66% vs 2%, p < 0.0001. Patients that achieved a hematologic CR were more likely to achieve a renal response (53% vs 24%, p = 0.001). Five year overall and renal survival for the entire cohort was 67% and 57%, respectively. In multivariate analyses, a baseline GFR < 20 mL/min/1.73 m² and a renal response (using AL or IMWG criteria) were independently predictive of progression to dialysis. This study confirms that deep hematologic responses, best achieved with ASCT or PI-based therapies, are a prerequisite to achieving renal responses. Am. J. Hematol. 91:1123-1128, 2016. © 2016 Wiley Periodicals, Inc.

Temporal IgG Subtype Changes in Recurrent Idiopathic Membranous Nephropathy

Determination of the IgG subtypes within the immune deposits in membranous nephropathy (MN) may be helpful in the differential diagnosis. IgG4 is the predominant subtype in idiopathic MN and recurrent MN, while IgG1, IgG2, and IgG3 subtypes are more common in secondary MN and de novo disease in the allograft. The temporal change of IgG subclasses in individual patients and its correlation with clinical variables have not been studied. We reviewed all posttransplantation protocol and indication biopsies (49) in 18 patients with recurrent MN who underwent transplantation at our center between 1998 and 2013 and performed IgG subtyping (IgG1-4). We tested serum for M-type phospholipase A2 receptor (PLA2 R) autoantibodies or performed PLA2 R antigen staining on the kidney biopsy. IgG4 was the (co)dominant IgG subtype in 10 of 14 biopsies at the diagnosis of recurrence regardless of PLA2 R association. In 8 of 12 transplantations with serial biopsies, the (co)dominant subtype did not change over time. There was a trend toward IgG1 and IgG3 (co)dominance in biopsies >1 year from recurrence and more IgG1 (co)dominant subtyping in the setting of more-advanced EM deposits. Treatment with rituximab did not affect the IgG subtype. In conclusion, the dominant IgG subtype did not change over time in recurrent MN.

Kidney transplantation as a therapeutic option for end-stage renal disease developing after heart transplantation

BACKGROUND

Progressive renal failure is a frequent complication after heart transplantation (HTx). It may result in end-stage renal disease (ESRD), prompting consideration of kidney Tx after HTx (KAH).

METHODS

We performed a retrospective single-center study of 268 HTx recipients to evaluate outcomes after KAH compared with HTx recipients with and without ESRD.

RESULTS

During a median follow-up of 76 months, ESRD developed in 51 patients (19), and 39 of them (76%) underwent KAH. The mean time from HTx to ESRD was 83 months. The incidence of switching to a calcineurin inhibitor (CNI)-free regimen based on sirolimus was significantly lower among recipients with ESRD (6% vs 57%, p = 0.0001), and prolonged exposure to CNI significantly increased the risk for ESRD (hazard ratio, 1.09; 95% confidence interval, 1.03-1.15; p < 0.005). Death-censored renal graft survival after KAH was 95%, 95%, and 83% at 1, 5, and 10 years, respectively. Median long-term survival of KAH patients was comparable to HTx recipients without ESRD (17.5 vs 17.1 years, p = 0.27) and significantly better compared with HTx recipients with ESRD (17.5 vs 7.3 years, p < 0.001).

CONCLUSIONS

Prolonged exposure to CNI immunosuppression medications significantly increases the risk for ESRD among HTx recipients. KAH is a good therapeutic option for HTx recipients with ESRD, with survival benefit comparable to HTx without ESRD.

Changing Kidney Allograft Histology Early Posttransplant: Prognostic Implications of 1-Year Protocol Biopsies

Allograft histology 1 year posttransplant is an independent correlate to long-term death-censored graft survival. We assessed prognostic implications of changes in histology first 2 years posttransplant in 938 first kidney recipients, transplanted 1999-2010, followed for 93.4 ± 37.7 months. Compared to implantation biopsies, histology changed posttransplant showing at 1 year that 72.6% of grafts had minor abnormalities (favorable histology), 20.2% unfavorable histology, and 7.2% glomerulonephritis. Compared to favorable, graft survival was reduced in recipients with unfavorable histology (hazards ratio [HR] = 4.79 [3.27-7.00], p < 0.0001) or glomerulonephritis (HR = 5.91 [3.17-11.0], p < 0.0001). Compared to unfavorable, in grafts with favorable histology, failure was most commonly due to death (42% vs. 70%, p < 0.0001) and less commonly due to alloimmune causes (27% vs. 10%, p < 0.0001). In 80% of cases, favorable histology persisted at 2 years. However, de novo 2-year unfavorable histology (15.3%) or glomerulonephritis (4.7%) related to reduced survival. The proportion of favorable grafts increased during this period (odds ratio = 0.920 [0.871-0.972], p = 0.003, per year) related to fewer DGF, rejections, polyoma-associated nephropathy (PVAN), and better function. Graft survival also improved (HR = 0.718 [0.550-0.937], p = 0.015) related to better histology and function. Evolution of graft histologic early posttransplant relate to long-term survival. Avoiding risk factors associated with unfavorable histology relates to improved histology and graft survival.

Mayo Clinic/Renal Pathology Society Consensus Report on Pathologic Classification, Diagnosis, and Reporting of GN

Renal pathologists and nephrologists met on February 20, 2015 to establish an etiology/pathogenesis-based system for classification and diagnosis of GN, with a major aim of standardizing the kidney biopsy report of GN. On the basis of etiology/pathogenesis, GN is classified into the following five pathogenic types, each with specific disease entities: immune-complex GN, pauci-immune GN, antiglomerular basement membrane GN, monoclonal Ig GN, and C3 glomerulopathy. The pathogenesis-based classification forms the basis of the kidney biopsy report. To standardize the report, the diagnosis consists of a primary diagnosis and a secondary diagnosis. The primary diagnosis should include the disease entity/pathogenic type (if disease entity is not known) followed in order by pattern of injury (mixed patterns may be present); score/grade/class for disease entities, such as IgA nephropathy, lupus nephritis, and ANCA GN; and additional features as detailed herein. A pattern diagnosis as the sole primary diagnosis is not recommended. Secondary diagnoses should be reported separately and include coexisting lesions that do not form the primary diagnosis. Guidelines for the report format, light microscopy, immunofluorescence microscopy, electron microscopy, and ancillary studies are also provided. In summary, this consensus report emphasizes a pathogenesis-based classification of GN and provides guidelines for the standardized reporting of GN.

Mayo Clinic/Renal Pathology Society Consensus Report on Pathologic Classification, Diagnosis, and Reporting of GN

Renal pathologists and nephrologists met on February 20, 2015 to establish an etiology/pathogenesis-based system for classification and diagnosis of GN, with a major aim of standardizing the kidney biopsy report of GN. On the basis of etiology/pathogenesis, GN is classified into the following five pathogenic types, each with specific disease entities: immune-complex GN, pauci-immune GN, antiglomerular basement membrane GN, monoclonal Ig GN, and C3 glomerulopathy. The pathogenesis-based classification forms the basis of the kidney biopsy report. To standardize the report, the diagnosis consists of a primary diagnosis and a secondary diagnosis. The primary diagnosis should include the disease entity/pathogenic type (if disease entity is not known) followed in order by pattern of injury (mixed patterns may be present); score/grade/class for disease entities, such as IgA nephropathy, lupus nephritis, and ANCA GN; and additional features as detailed herein. A pattern diagnosis as the sole primary diagnosis is not recommended. Secondary diagnoses should be reported separately and include coexisting lesions that do not form the primary diagnosis. Guidelines for the report format, light microscopy, immunofluorescence microscopy, electron microscopy, and ancillary studies are also provided. In summary, this consensus report emphasizes a pathogenesis-based classification of GN and provides guidelines for the standardized reporting of GN.

Volume regression of native polycystic kidneys after renal transplantation

BACKGROUND

The natural course of native kidneys after renal transplantation (RT) or dialysis in patients with autosomal dominant polycystic kidney disease (ADPKD) remains poorly understood.

METHODS

We measured the total volumes of native kidneys and liver in 78 and 68 ADPKD patients, respectively, who had pre-transplant (within 2 years) and at least one post-transplant computed tomography (CT)/magnetic resonance imaging (MRI); in 40 patients with at least two post-transplant but no pre-transplant CT/MRIs; in 9 patients on chronic hemodialysis with at least one CT/MRI before and after beginning dialysis; and in 5 patients who had no image before and more than one image after dialysis. The last imaging was used in patients with multiple studies.

RESULTS

Mean total kidney volume (TKV) ( ± SD) prior to transplantation was 3187 ± 1779 mL in the 78 patients who had imaging before and after transplantation and decreased by 20.2, 28.6, 38.3 and 45.8% after 0.5-1 (mean 0.7), 1-3 (1.8), 3-10 (5.7) and >10 (12.6) years, respectively. In the multivariable analysis, time on dialysis prior to RT and time from baseline to transplantation were negatively associated with reduction in TKV, whereas estimated glomerular filtration rate (eGFR) after transplantation and time from transplantation were positively associated with percent reduction in TKV. In the 40 patients with imaging only after transplantation, TKV decreased by 3.2 ± 16.3% between 7.2 ± 6.0 and 11.2 ± 6.8 years after transplantation (P < 0.001). TKV was 11.2 ± 35.6% higher (P = NS) after a follow-up of 3.4 ± 2.0 years in the 9 patients with imaging before and after initiation of hemodialysis and 3.4 ± 40.2% lower (P = NS) in the 5 patients with imaging between 2.0 ± 2.1 and 3.5 ± 3.6 years after initiation of hemodialysis. In the 68 patients with liver measurements, volume increased by 5.8 ± 17.9% between baseline and follow-up at 3.7 ± 3.8 years after transplantation (P = 0.009).

CONCLUSIONS

TKV of native polycystic kidneys decreases substantially after RT. The reduction occurs mainly during the early post-transplantation period and more slowly thereafter.

Adherence to a pedometer-based physical activity intervention following kidney transplant and impact on metabolic parameters

The majority of kidney transplant recipients die from cardiovascular events. Physical activity may be a modifiable risk factor for cardiovascular disease following transplant. The goal of our study was to examine adherence to a physical activity intervention following kidney transplant and its impact on metabolic parameters. All patients who received a kidney transplant at our center between 12/2010 and 12/2011 received usual care (n = 162), while patients transplanted between 12/2011 and 1/2013 received a 90-day pedometer-based physical activity intervention (n = 145). Metabolic parameters were assessed at four and 12 months post-transplant. Baseline demographics and clinical management were similar between cohorts. Adherence to the prescription was 36.5%. Patients in the physical activity cohort had lower systolic and diastolic blood pressure four months post-transplant compared to the usual care cohort (122 ± 18 vs. 126 ± 16 mmHg, p = 0.049 and 73 ± 10 vs. 77 ± 9, p = 0.004) and less impaired fasting glucose (20.7% vs. 30.9%, p = 0.04). Twelve-month outcomes were not different between cohorts. Over one-third of our cohort adhered to a pedometer-based physical activity intervention following kidney transplant, and the intervention was associated with improved metabolic parameters. Further study of post-transplant exercise interventions and methods to optimize long-term adherence are needed.

Anti-phospholipase A₂ receptor antibodies in recurrent membranous nephropathy

About 70% of patients with primary membranous nephropathy (MN) have circulating anti-phospholipase A2 receptor (PLA2R) antibodies that correlate with disease activity, but their predictive value in post-transplant (Tx) recurrent MN is uncertain. We evaluated 26 patients, 18 with recurrent MN and 8 without recurrence, with serial post-Tx serum samples and renal biopsies to determine if patients with pre-Tx anti-PLA2R are at increased risk of recurrence as compared to seronegative patients and to determine if post-Tx changes in anti-PLA2R correspond to the clinical course. In the recurrent group, 10/17 patients had anti-PLA2R at the time of Tx versus 2/7 patients in the nonrecurrent group. The positive predictive value of pre-Tx anti-PLA2R for recurrence was 83%, while the negative predictive value was 42%. Persistence or reappearance of post-Tx anti-PLA2R was associated with increasing proteinuria and resistant disease in 6/18 cases; little or no proteinuria occurred in cases with pre-Tx anti-PLA2R and biopsy evidence of recurrence in which the antibodies resolved with standard immunosuppression. Some cases with positive pre-Tx anti-PLA2R were seronegative at the time of recurrence. In conclusion, patients with positive pre-Tx anti-PLA2R should be monitored closely for recurrent MN. Persistence or reappearance of antibody post-Tx may indicate a more resistant disease.

Through a glass darkly: seeking clarity in preventing late kidney transplant failure

A common lament is that long-term kidney transplant outcomes remain the same despite improvements in early graft survival. To be fair, progress has been made-in both our understanding of chronic injury and modestly, graft survival. However, we are still a long way from actually solving this important and difficult problem. In this review, we outline recent data supporting the existence of several causes of renal allograft loss, the incidences of which peak at different time points after transplantation. On the basis of this broadened concept of chronic renal allograft injury, we examine the challenges of clinical trial design in long-term studies, including the use of surrogate end points and biomarkers. Finally, we suggest a path forward that, ultimately, may improve long-term renal allograft survival.

Kidney allograft function and histology in recipients dying with a functioning graft

Death with function (DWF) is a major cause of kidney allograft failure. Allograft dysfunction may contribute to DWF. The aim of this study was to examine the relationship between DWF and allograft function using estimated GFR (eGFR) and histology. We retrospectively analyzed 1842 kidney allografts transplanted at our center from 1996 to 2010. eGFR was estimated using the MDRD equation. Biopsies obtained 12 months posttransplant and within 1 year of DWF were analyzed. Proportional hazards models were used to examine the relationship between eGFR and DWF. During 68 ± 43 months of follow-up, 14% (n = 256) of recipients experienced DWF. Risk factors of DWF included increasing recipient age (hazard ratio [HR] = 2.07, confidence interval [CI] 1.77-2.43, p < 0.0001), diabetes (HR = 2.58, CI 1.81-3.69, p < 0.0001), prior dialysis (HR = 1.47, CI 1.05-2.06, p = 0.03) and eGFR <40 mL/min/1.73 m(2) (HR 2.26 per 10 mL/min/1.73 m(2) decrease in eGFR, CI 1.82-2.81, p < 0.0001). Prior to death, only 15.9% (n = 39) of DWF recipients had stage 4 chronic kidney disease (CKD) and only 4.9% (n = 12) had stage 5 CKD. Most biopsies performed within 1 year of DWF (68%) demonstrated benign histology and were comparable to biopsies from matched controls. In conclusion, allograft dysfunction is independently associated with DWF. However, the majority of DWF recipients have well-preserved allograft function and histology prior to death.

Impact of urinary tract infection on allograft function after kidney transplantation

OBJECTIVES

Urinary tract infection (UTI) is the most common infectious complication after kidney transplantation. We aim to determine its impact on allograft function as indicated by several measures such as iothalamate glomerular filtration rate (iGFR), estimated glomerular filtration rate (eGFR), and creatinine value.

METHODS

We performed a single-center retrospective cohort study to determine the impact of UTI on kidney allograft outcome.

RESULTS

The study population consisted of 301 kidney transplant recipients; 84% were living donor transplants. One hundred and one patients (34%) developed at least one episode of UTI and the incidence of UTI during the first year after transplantation was 25%. At the end of the follow-up, the iGFR was lower among patients who had developed at least one UTI (p = 0.044). However, eGFR and creatinine values were not significantly different between UTI and non-UTI groups.

CONCLUSION

When kidney function was measured by eGFR and creatinine, there was no significant difference in allograft function between kidney recipients with or without UTI. However, when kidney function was measured by nuclear studies, there was a tendency toward impairment in allograft function among patients who developed atleast one UTI after transplantation.

Clinical findings, pathology, and outcomes of C3GN after kidney transplantation

C3 glomerulonephritis (C3GN) results from abnormalities in the alternative pathway of complement, and it is characterized by deposition of C3 with absent or scant Ig deposition. In many patients, C3GN progresses to ESRD. The clinical features, pathology, and outcomes of patients with C3GN receiving kidney transplantation are unknown. Between 1996 and 2010, we identified 21 patients at our institution who received a kidney transplant because of ESRD from C3GN. The median age at the time of initial diagnosis of C3GN at kidney biopsy was 20.8 years. The median time from native kidney biopsy to dialysis or transplantation was 42.3 months. Of 21 patients, 14 (66.7%) patients developed recurrent C3GN in the allograft. The median time to recurrence of disease was 28 months. Graft failure occurred in 50% of patients with recurrent C3GN, with a median time of 77 months to graft failure post-transplantation. The remaining 50% of patients had functioning grafts, with a median follow-up of 73.9 months. The majority of patients had hematuria and proteinuria at time of recurrence. Three (21%) patients were positive for monoclonal gammopathy and had a faster rate of recurrence and graft loss. Kidney biopsy at the time of recurrence showed mesangial proliferative GN in eight patients and membranoproliferative GN in six patients. All allograft kidney biopsies showed bright C3 staining (2-3+), with six biopsies also showing trace/1+ staining for IgM and/or IgG. To summarize, C3GN recurs in 66.7% of patients, and one half of the patients experience graft failure caused by recurrence.

Kidney allograft survival after acute rejection, the value of follow-up biopsies

Kidney allografts are frequently lost due to alloimmunity. Still, the impact of early acute rejection (AR) on long-term graft survival is debated. We examined this relationship focusing on graft histology post-AR and assessing specific causes of graft loss. Included are 797 recipients without anti-donor antibodies (DSA) at transplant who had 1 year protocol biopsies. 15.2% of recipients had AR diagnosed by protocol or clinical biopsies. Compared to no-AR, all histologic types of AR led to abnormal histology in 1 and 2 years protocol biopsies, including more fibrosis + inflammation (6.3% vs. 21.9%), moderate/severe fibrosis (7.7% vs. 13.5%) and transplant glomerulopathy (1.4% vs. 8.3%, all p < 0.0001). AR were associated with reduced graft survival (HR = 3.07 (1.92-4.94), p < 0.0001). However, only those AR episodes followed by abnormal histology led to reduced graft survival. Early AR related to more late alloimmune-mediated graft losses, particularly transplant glomerulopathy (31% of losses). Related to this outcome, recipients with AR were more likely to have new DSA class II 1 year posttransplant (no-AR, 11.1%; AR, 21.2%, p = 0.039). In DSA negative recipients, early AR often leads to persistent graft inflammation and increases the risk of new DSA II production. Both of these post-AR events are associated with increased risk of graft loss.

Oral paricalcitol reduces the prevalence of posttransplant hyperparathyroidism: results of an open label randomized trial

Postkidney transplant hyperparathyroidism is a significant problem. Vitamin D receptor agonists are known to suppress parathyroid hormone (PTH) secretion. We examined the effect of oral paricalcitol on posttransplant secondary hyperparathyroidism by conducting an open label randomized trial in which 100 incident kidney transplant recipients were randomized 1:1 to receive oral paricalcitol, 2 μg per day, for the first year posttransplant or no additional therapy. Serial measurements of serum PTH, calcium and bone alkaline phosphatase, 24-h urine calcium and bone density were performed. The primary endpoint was the frequency of hyperparathyroidism 1-year posttransplant. Eighty-seven patients completed the trial. One-year posttransplant, 29% of paricalcitol-treated subjects had hyperparathyroidism compared with 63% of untreated patients (p = 0.0005). Calcium supplementation was discontinued in two control and 15 treatment patients due to mild hypercalcemia or hypercalcuria. Paricalcitol was discontinued in four patients due to hypercalcuria/hypercalcemia and in one for preference. Two subjects required decreasing the dose of paricalcitol to 1 μg daily. Hypercalcemia was asymptomatic and reversible. Incidence of acute rejection, BK nephropathy and renal function at 1 year were similar between groups. Moderate renal allograft fibrosis was reduced in treated patients. Oral paricalcitol is effective in decreasing posttransplant hyperparathyroidism and may have beneficial effects on renal allograft histology.

Acute pancreas allograft rejection is associated with increased risk of graft failure in pancreas transplantation

The effect of acute allograft rejection (AR) on long-term pancreas allograft function is unclear. We retrospectively studied 227 consecutive pancreas transplants performed at our institution between January 1, 998 and December 31, 2009 including: 56 simultaneous pancreas and kidney (SPK), 69 pancreas transplantation alone (PTA); and 102 pancreas after kidney (PAK) transplants. With a median follow-up of 6.1 (IQR 3-9) years, 57 patients developed 79 episodes of AR, and 19 experienced more than one episode. The cumulative incidence for AR was 14.7%, 19.7%, 26.6% and 29.1% at 1, 2, 5 and 10 years. PTA transplant (hazards ratio [HR]=2.28, p=0.001) and donor age (per 10 years) (HR=1.34, p=0.006) were associated with higher risk for AR. The first AR episode after 3 months post PT was associated with increased risk for complete loss (CL) (HR 3.79, p<0.001), and the first AR episode occurring during 3- to 12-month and 12- to 24-month periods after PT were associated with significantly increased risk for at least partial loss (PL) (HR 2.84, p=0.014; and HR 6.25, p<0.001, respectively). We conclude that AR is associated with increased risk for CL and at least PL. The time that the first AR is observed may influence subsequent graft failure.

A prospective controlled study of kidney donors: baseline and 6-month follow-up

BACKGROUND

Most previous studies of living kidney donors have been retrospective and have lacked suitable healthy controls. Needed are prospective controlled studies to better understand the effects of a mild reduction in kidney function from kidney donation in otherwise healthy individuals.

STUDY DESIGN

Prospective, controlled, observational cohort study.

SETTING & PARTICIPANTS

Consecutive patients approved for donation at 8 transplant centers in the United States were asked to participate. For every donor enrolled, an equally healthy control with 2 kidneys who theoretically would have been suitable to donate a kidney also was enrolled.

PREDICTOR

Kidney donation.

MEASUREMENTS

At baseline predonation and at 6 months after donation, medical history, vital signs, measured (iohexol) glomerular filtration rate, and other measurements were collected. There were 201 donors and 198 controls who completed both baseline and 6-month visits and form the basis of this report.

RESULTS

Compared with controls, donors had 28% lower glomerular filtration rates at 6 months (94.6 ± 15.1 [SD] vs 67.6 ± 10.1 mL/min/1.73 m(2); P < 0.001), associated with 23% greater parathyroid hormone (42.8 ± 15.6 vs 52.7 ± 20.9 pg/mL; P < 0.001), 5.4% lower serum phosphate (3.5 ± 0.5 vs 3.3 ± 0.5 mg/dL; P < 0.001), 3.7% lower hemoglobin (13.6 ± 1.4 vs 13.1 ± 1.2 g/dL; P < 0.001), 8.2% greater uric acid (4.9 ± 1.2 vs 5.3 ± 1.1 mg/dL; P < 0.001), 24% greater homocysteine (1.2 ± 0.3 vs 1.5 ± 0.4 mg/L; P < 0.001), and 1.5% lower high-density lipoprotein cholesterol (54.9 ± 16.4 vs 54.1 ± 13.9 mg/dL; P = 0.03) levels. There were no differences in albumin-creatinine ratios (5.0 [IQR, 4.0-6.6] vs 5.0 [IQR, 3.3-5.4] mg/g; P = 0.5), office blood pressures, or glucose homeostasis.

LIMITATIONS

Short duration of follow-up and possible bias resulting from an inability to screen controls with kidney and vascular imaging performed in donors.

CONCLUSIONS

Kidney donors have some, but not all, abnormalities typically associated with mild chronic kidney disease 6 months after donation. Additional follow-up is warranted.

Urine high and low molecular weight proteins one-year post-kidney transplant: relationship to histology and graft survival

Increased urinary protein excretion is common after renal transplantation and portends worse outcome. In this study we assessed the prognostic contribution of several urinary proteins. Urinary total protein, albumin, retinol binding protein (RBP), α-1-microglobulin, IgG and IgM were measured in banked urine samples from 221 individuals 1 year after renal transplantation (age 52 ± 13 years, 55% male, 93% Caucasian and 82% living donor). Levels of all proteins measured were higher than in normal nontransplant populations. Patients with glomerular lesions had higher urinary albumin than those with normal histology, while those with interstitial fibrosis and tubular atrophy plus inflammation (ci>0, cg = 0, i>0) had higher levels of IgG, IgM, α-1-microglobulin and RBP. Concomitant normal levels of urinary albumin, IgM and RBP identified normal histology (specificity 91%, sensitivity 15%,). Urinary levels of the specific proteins were highly correlated, could not differentiate among the histologic groups, and appeared to result from tubulointerstitial damage. Increased urinary excretion of the low molecular weight protein RBP was a sensitive marker of allografts at risk, predicting long-term graft loss independent of histology and urinary albumin. This study highlights the prognostic importance of tubulointerstitial disease for long-term graft loss.

Cardiac troponin T before and after kidney transplantation: determinants and implications for posttransplant survival

Pretransplant cardiac troponin T(cTnT(pre) ) is a significant predictor of survival postkidney transplantation. We assessed correlates of cTnT levels pre- and posttransplantation and their relationship with recipient survival. A total of 1206 adult recipients of kidney grafts between 2000 and 2010 were included. Pretransplant cTnT was elevated (≥0.01 ng/mL) in 56.4%. Higher cTnT(pre) was associated with increased risk of posttransplant death/cardiac events independent of cardiovascular risk factors. Elevated cTnT(pre) declined rapidly posttransplant and was normal in 75% of recipients at 3 weeks and 88.6% at 1 year. Elevated posttransplant cTnT was associated with reduced patient survival (cTnT(3wks) : HR = 5.575, CI 3.207-9.692, p < 0.0001; cTnT(1year) : 3.664, 2.129-6.305, p < 0.0001) independent of age, diabetes, pretransplant dialysis, heart disease and allograft function. Negative/positive predictive values for high cTnT(3wks) were 91.4%/50% respectively. Normalization of cTnT posttransplant was associated with reduced risk. Variables related to elevated cTnT posttransplant included pretransplant diabetes, older age, time on dialysis, high cTnT(pre) and lower graft function. Patients with delayed graft function and those with GFR < 30 mL/min at 3 weeks were more likely to have an elevated cTnT(3wks) and remained at high risk. When allografts restore sufficient kidney function cTnT normalizes and patient survival improves. Lack of normalization of cTnT posttransplant identifies a group of individuals with high risk of death/cardiac events.

Desensitization in the era of kidney paired donation: the Mayo Foundation 3-site experience

Sensitized renal allograft candidates face significant barriers to transplantation. While several options exist, including: kidney paired donation (KPD), desensitization, or pursuing a deceased donor kidney transplant, it is unclear from existing data what is the appropriate protocol for an individual patient. In this study, we seek to devise a balance between waiting for a paired donor and combining desensitization with KPD.

Cellular and physiological mechanisms of new-onset diabetes mellitus after solid organ transplantation

New-onset diabetes after transplantation is recognized as one of the metabolic consequences which may increase the risk of morbidity and mortality after solid organ transplantation. The pathophysiology of new-onset diabetes after transplantation has not been clearly defined and may resemble that of Type 2 diabetes, characterized by predominantly insulin resistance or defective insulin secretion, or both. This review aims to summarize the current state of knowledge regarding the prevalence, consequences, pathogenesis, and management of new-onset diabetes after transplantation, with a major focus on the possible mechanisms involved in the pathogenesis of the disorder. The aetiology of new-onset diabetes after transplantation is multifactorial, with diabetogenic immunosuppressive drugs playing a major role. Multiple cellular and physiologic mechanisms are involved in the process. Selection of an appropriate maintenance immunosuppressive regimen should involve balancing the risk of patient and graft survival vs. the potential for new-onset diabetes after transplantation.

Kidney allograft inflammation and fibrosis, causes and consequences

This study assessed the development of allograft interstitial fibrosis and inflammation (GIF+"i"), a histologic pattern associated with reduced graft survival. Included are 795 adults, recipients of kidney allografts from 2000 to 2006. GIF+"i" was diagnosed in surveillance and clinical biopsies that had no transplant glomerulopathy. With time, posttransplant increasing number of grafts showed GIF+"i" and these patients had reduced death-censored graft survival (HR = 4.33 (2.49-7.53), p < 0.0001). Development of GIF+"i" was related to prior acute cellular rejection (ACR), BK nephropathy (PVAN), increasing number of HLA mismatches, retransplantation and DGF. However, 46.4% of GIF+"i" cases had no history of ACR or PVAN. Anti-HLA antibodies at transplant did not relate to GIF+"i" and these patients had no increased frequency of new antibody formation posttransplant. Post-ACR biopsies showed that GIF+"i" developed more commonly after clinically and/or histologically more severe ACR. Graft inflammation persisted in 38.7 and 29.6% of grafts 2 and 12 months post-ACR. Twelve months post-ACR, 27.1% of biopsies developed moderate-severe GIF and 51.8% showed GIF and inflammation. Persistent inflammation and progressive GIF is often subclinical but may lead to graft failure. GIF+"i" can be initiated by multiple etiologies but it is often postinfectious or due to persistent cellular immune-mediated injury.

Long-term follow-up of patients with monoclonal gammopathy of undetermined significance after kidney transplantation

INTRODUCTION

Long-term data regarding kidney transplantation (KTx) patients with monoclonal gammopathy of undetermined significance (MGUS) are scarce. We evaluated the long-term outcomes of these patients in a single-center retrospective study from the Mayo Clinic, Rochester, Minn., USA.

METHODS

Patients who had an MGUS before transplant or developed one after KTx were selected. Monoclonal protein was screened as part of the KTx evaluation by serum protein electrophoresis. Screening for posttransplant lymphoproliferative disorder (PTLD) or MGUS after transplant was not required by protocol. Patients with multiple myeloma, dysproteinemia-related kidney disease or no pretransplant serum protein electrophoresis were excluded.

RESULTS

Between 1963 and 2006, 3,518 patients underwent KTx. MGUS was identified in 42 patients, with 23 before transplant and 19 after transplant. Median follow-up for these patients was 8.5 years (range 0.3-37). Four (17.4%) pretransplant MGUS patients developed a hematologic malignancy: 2 smoldering multiple myeloma and 2 PTLD - an Epstein-Barr virus-positive diffuse large cell lymphoma and a Hodgkin lymphoma. None of the 19 patients who developed an MGUS after transplant progressed to multiple myeloma, but 2 (10.5%) developed Epstein-Barr virus-negative T cell lymphoproliferative disorders at 16 and 26 years after transplant. Median survival was 26.1 and 28.0 years for the pretransplant and posttransplant MGUS groups, respectively.

CONCLUSION

Progression from true MGUS to multiple myeloma is rare after KTx. KTx appears safe in true MGUS patients if the monoclonal gammopathy was not the cause of the kidney disease. None of the patients progressed to multiple myeloma, but 2 developed smoldering multiple myeloma and several developed PTLD. Further studies are needed to explain the relationship between MGUS and PTLD.

The pathology and clinical features of early recurrent membranous glomerulonephritis

We assessed the earliest manifestations of recurrent membranous glomerulonephritis (MGN) in renal allografts. Clinical, laboratory and pathologic data were reviewed in 21 patients at the initial biopsy within 4 months post-transplant with evidence of MGN and on follow-up biopsies, compared to a biopsy control group of eight transplants without recurrent MGN. The mean time of first biopsy with pathologic changes was 2.7 months. In each earliest biopsy, immunofluorescence (IF) showed granular glomerular basement membrane (GBM) staining for C4d, IgG, kappa and lambda. IF for C3 was negative or showed trace staining in 16/21. On each MGN biopsy positive by IF, 14/19 showed absence of deposits or rare tiny subepithelial deposits by electron microscopy (EM). At the earliest biopsy, the mean proteinuria was 1.1 g/day; 16 patients had <1 g/day proteinuria. Follow-up was available in all patients (mean 35 months posttransplant). A total of 13 patients developed >1 g/day proteinuria; 12 were treated with: rituximab (n = 8), ACEI and increased prednisone dose (n = 2), ACEI or ARB only (n = 2). All patients showed reduction in proteinuria after treatment. A total of 11/16 patients showed progression of disease by EM on follow-up biopsy. Recognition of early allograft biopsy features aids in diagnosis of recurrent MGN before patients develop significant proteinuria.

Bilateral native ureteral ligation without nephrectomy in the management of kidney transplant recipients with native proteinuria

The aim of this study was to assess the safety of bilateral native ureteral ligation (BNUL) without nephrectomy in the management of native proteinuria in kidney transplant (KTx) recipients. We retrospectively studied 17 patients who underwent BNUL between 2002 and 2010 with a median preoperative 24 h protein concentration of 2140 (range 1020-25 000) mg/L. Fifteen of the 17 patients had focal segmental glomerulosclerosis as their primary renal disease and ligation was employed to facilitate the diagnosis of early recurrence. The BNUL was performed simultaneously with KTx in 14 patients. Surgical techniques were: open (n = 5), pure laparoscopic (n = 1) and a hybrid of hand-assisted laparoscopic surgical/open approach (n = 12) used at the time of transplantation via the transplant incision. At a median follow-up of 46 months (range 1-59), no patient had a complication related to BNUL and none required interventions associated with their native kidneys. BNUL without nephrectomy seems to be a safe technique to manage native proteinuria in renal transplant candidates.

Terminal complement inhibition decreases antibody-mediated rejection in sensitized renal transplant recipients

Sensitized renal transplant recipients with high levels of donor-specific alloantibody (DSA) commonly develop antibody-mediated rejection (AMR), which may cause acute graft loss or shorten allograft survival. We examined the efficacy of terminal complement inhibition with the humanized anti-C5 antibody, eculizumab, in the prevention AMR in renal transplant recipients with a positive crossmatch against their living donor. The incidence of biopsy-proven AMR in the first 3 months posttransplant in 26 highly sensitized recipients of living donor renal transplants who received eculizumab posttransplant was compared to a historical control group of 51 sensitized patients treated with a similar plasma exchange (PE)-based protocol without eculizumab. The incidence of AMR was 7.7% (2/26) in the eculizumab group compared to 41.2% (21/51) in the control group (p = 0.0031). Eculizumab also decreased AMR in patients who developed high levels of DSA early after transplantation that caused proximal complement activation. With eculizumab, AMR episodes were easily treated with PE reducing the need for splenectomy. On 1-year protocol biopsy, transplant glomerulopathy was found to be present in 6.7% (1/15) eculizumab-treated recipients and in 35.7% (15/42) of control patients (p = 0.044). Inhibition of terminal complement activation with eculizumab decreases the incidence of early AMR in sensitized renal transplant recipients (ClincalTrials.gov number NCT006707).

Rituximab-induced depletion of anti-PLA2R autoantibodies predicts response in membranous nephropathy

Autoantibodies to the M-type phospholipase A(2) receptor (PLA(2)R) are sensitive and specific for idiopathic membranous nephropathy. The anti-B cell agent rituximab is a promising therapy for this disease, but biomarkers of early response to treatment currently do not exist. Here, we investigated whether levels of anti-PLA(2)R correlate with the immunological activity of membranous nephropathy, potentially exhibiting a more rapid response to treatment than clinical parameters such as proteinuria. We measured the amount of anti-PLA(2)R using Western blot immunoassay in serial serum samples from a total of 35 patients treated with rituximab for membranous nephropathy in two distinct cohorts. Pretreatment samples from 25 of 35 (71%) patients contained anti-PLA(2)R, and these autoantibodies declined or disappeared in 17 (68%) of these patients within 12 months after rituximab. Those who demonstrated this immunologic response fared better clinically: 59% and 88% attained complete or partial remission by 12 and 24 months, respectively, compared with 0% and 33% among those with persistent anti-PLA(2)R levels. Changes in antibody levels preceded changes in proteinuria. One subject who relapsed during follow-up had a concomitant return of anti-PLA(2)R. In summary, measuring anti-PLA(2)R levels by immunoassay may be a method to follow and predict response to treatment with rituximab in membranous nephropathy.

Improving long-term renal allograft survival via a road less traveled by

It has become cliché to state that improvements in early renal allograft survival over the past two decades have not led to increased long-term renal allograft survival. However, it is not clear how long-term graft survival can be improved. Here, we present the viewpoint that the road forward does not involve searching for new and more ideal immunosuppressive regimens, but rather detailed patient follow-up to identify specific causes of late renal allograft loss and the development of new therapy designed to address these problems before allograft damage becomes irreversible.

Living donor age and kidney transplant outcomes

We assessed the relationship between living donor (LD) age and kidney survival in 1063 adults transplanted between 1980 and 2007. Increasing LD age was associated with lower kidney function (GFR) before and after transplantation and loss of GFR beyond 1 year. Increasing LD age was also associated with low-moderate proteinuria posttransplant (151-1500 mg/day, p < 0.0001). By univariate analysis, reduced graft survival related to lower GFR at 1 year [HR = 0.925 (0.906-0.944), p < 0.0001], proteinuria [HR = 1.481 (1.333-1.646), p < 0.0001] and increasing LD age [HR = 1.271 (1.219-1.326), p = 0.001]. The impact of LD age on graft survival was noted particularly >4 years posttransplant and was modified by recipient age. Thus, compared to a kidney graft that was within 5 years of the recipient age, younger kidneys had a survival advantage [HR = 0.600 (0.380-0.949), p = 0.029] while older kidneys had a survival disadvantage [HR = 2.217 (1.507-3.261), p < 0.0001]. However, this effect was seen only in recipients <50 years old. By multivariate analysis, the relationship between LD age and graft survival was independent of GFR but related to proteinuria. In conclusion, LD age is an important determinant of long-term graft survival, particularly in younger recipients. Older kidneys with reduced survival are identifiable by the development of proteinuria posttransplant.

The histology of solitary renal allografts at 1 and 5 years after transplantation

Previous studies suggest that the majority of renal allografts are affected by progressive, severe chronic histologic injury, yet studies using current protocols are lacking. The goal of this study was to examine the prevalence and progression of histologic changes using protocol allograft biopsies at 1 and 5 years after solitary kidney transplantation in patients transplanted between 1998 and 2004. Chronic histologic changes generally were mild at both 1 and 5 years and were similar in deceased and living donor kidneys. The overall prevalence of moderate or severe fibrosis was 13% (60/447) at 1 year and 17% (60/343) at 5 years. In a subgroup of 296 patients who underwent both 1- and 5-year biopsies, mild fibrosis present at 1 year progressed to more severe forms at 5 years in 23% of allografts. The prevalence of moderate or severe arteriolar hyalinosis was similar in tacrolimus and calcineurin inhibitor-free immunosuppression. These results in the recent era of transplantation demonstrate fewer, less severe and less progressive chronic histologic changes in the first 5 years after transplantation than previously reported.

Proliferative glomerulonephritis with monoclonal IgG deposits recurs in the allograft

BACKGROUND AND OBJECTIVES

Proliferative GN with monoclonal IgG deposits (PGNMID) is a newly described entity resembling immune complex GN. Its potential to recur in the allograft is undefined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The first cases of recurrent PGNMID in the allograft are reported.

RESULTS

The cohort includes four Caucasians (3 women, 1 man) with a mean age 58.5 years. No patient had M spike or hematologic malignancy. Recurrence was first documented by biopsy at a mean of 3.8 months posttransplant for indications of renal insufficiency in four patients, proteinuria in three patients, and microhematuria in three patients. Monoclonal IgG deposits (3 IgG3κ and 1 IgG3λ) in the transplants had identical heavy- and light-chain isotypes as in the native kidneys. In two patients, a pattern of endocapillary GN was identified in the native and transplant biopsies, whereas two patients with membranoproliferative GN in the native kidney developed endocapillary or mesangial GN in the transplant. Recurrence was treated with combined high-dose prednisone plus rituximab (n = 3) or plus cyclophosphamide (n = 1). After a mean posttransplant follow-up of 43 months, all four patients achieved reduction in proteinuria and three had reduction in creatinine. Repeat biopsies showed reduced histologic activity after treatment.

CONCLUSIONS

PGNMID can recur in the transplant despite the absence of a serum M spike. Recurrence is heralded by proteinuria, hematuria, and allograft dysfunction and manifests diverse histologic patterns. Although the pathogenesis remains unknown, early immunosuppressive therapy appears to stabilize the course.