Biopsy-diagnosed renal disease in patients after transplantation of other organs and tissues

Kidney Biopsy Findings After Lung Transplantation

Introduction

The early diagnosis of histological kidney damage after lung transplantation (LT) is of paramount importance given the negative prognostic implications of kidney disease.

Methods

Three pathologists analyzed all kidney biopsies (KBs) (N = 100) performed from 2010 to 2021 on lung transplant patients in 4 Paris transplantation centers.

Results

The main indication for biopsy was chronic renal dysfunction (72% of patients). Biopsies were performed at a median of 26.3 months after transplantation and 15 months after a decline in estimated glomerular filtration rate (eGFR) or the onset of proteinuria. Biopsies revealed a wide spectrum of chronic lesions involving the glomerular, vascular, and tubulointerstitial compartments. The 4 most frequent final diagnoses, observed in 18% to 49% of biopsies, were arteriosclerosis, acute calcineurin inhibitor (CNI) toxicity, thrombotic microangiopathy (TMA) and acute tubular necrosis (ATN). TMA was significantly associated with a combination of mTOR inhibitors (mTORi) or CNIs with biological signs present in only 50% of patients. The eGFR was poorly correlated with most lesions, particularly percent glomerulosclerosis, and with the risk of end-stage renal disease (ESRD). Thirty-four patients progressed to ESRD at an average of 20.1 months after biopsy. Three factors were independently associated with the risk of ESRD: postoperative dialysis, proteinuria >3 g/g and percent glomerulosclerosis >4%.

Conclusion

Given the great diversity of renal lesions observed in lung transplant recipients, early referral to nephrologists for KB should be considered for these patients when they present with signs of kidney disease.

Development and implementation of evidence-based, nurse-leading early warning model and healthcare quality improvement project for transplant-associated thrombotic microangiopathy: a mixed-methods, before-and-after study

OBJECTIVE

The early identification and diagnosis of transplant-associated thrombotic microangiopathy (TA-TMA) are essential yet difficult in patients underwent hematopoietic stem cell transplantation (HSCT). To develop an evidence-based, nurse-leading early warning model for TA-TMA, and implement the healthcare quality review and improvement project.

METHODS

This study was a mixed-methods, before-and-after study. The early warning model was developed based on quality evidence from literature search. The healthcare quality review and improvement project mainly included baseline investigation of nurse, improvement action and effectiveness evaluation. The awareness and knowledge of early parameter of TA-TMA among nurses and the prognosis of patients underwent HSCT were compared before and after the improvement.

RESULTS

A total of 1 guideline, 1 evidence synthesis, 4 expert consensuses, 10 literature reviews, 2 diagnostic studies, and 9 case series were included in the best evidence. The early warning model including warning period, high-risk characteristics and early manifestation of TA-TMA was developed. The improvement action, including staff training and assessment, suspected TA-TMA identification and patient education, was implemented. The awareness and knowledge rate of early parameter of TA-TMA among nurses significantly improved after improvement action (100% vs. 26.7%, P < 0.001). The incidence of TA-TMA was similar among patients underwent HSCT before and after improvement action (2.8% vs. 1.2%, P = 0.643), while no fall event occurred after improvement action (0 vs. 1.2%, P < 0.001).

CONCLUSION

The evidence-based early warning model and healthcare quality improvement project could enhance the awareness and knowledge of TA-TMA among healthcare providers and might improve the prognosis of patients diagnosed with TA-TMA.

Calcineurin inhibition, cardiovascular consequences, vascular resistance, and potential responses

AIM

To place the consequences of calcineurin inhibition in a cardiovascular context.

METHODS

Literature review coupled with personal encounters.

RESULTS

Calcineurin is a calcium-binding and calmodulin-binding protein that is conserved across evolution from yeast to mammals. The enzyme functions as a calcium-dependent, calmodulin-stimulated protein phosphatase. Its role in regulating physiology has largely been elucidated by observing calcineurin inhibition. Calcineurin inhibition transformed organ transplantation from an experiment into a therapy and made much of general immunotherapy possible. The function of this phosphatase and how its inhibition leads to toxicity concern us to this date. Initial research from patients and animal models implicated a panoply of factors contributing to hypertension and vasculopathy. Subsequently, the role of calcineurin in regulating the effective fluid volume, sodium reabsorption, and potassium and hydrogen ion excretion was elucidated by investigating calcineurin inhibition. Understanding the regulatory effects of calcineurin on endothelial and vascular smooth muscle cell function has also made substantial progress. However, precisely how the increase in systemic vascular resistance arises requires further mechanistic research.

CONCLUSION

Calcineurin inhibition continues to save lives; however, options to counteract the negative effects of calcineurin inhibition should be vigorously pursued.

Role of the Nephrologist in Non-Kidney Solid Organ Transplant (NKSOT)

BACKGROUND

Chronic kidney disease (CKD) is a common complication of a non-kidney solid organ transplant (NKSOT). Identifying predisposing factors is crucial for an early approach and correct referral to nephrology.

METHODS

This is a single-center retrospective observational study of a cohort of CKD patients under follow-up in the Nephrology Department between 2010 to 2020. Statistical analysis was performed between all the risk factors and four dependent variables: end-stage renal disease (ESKD); increased serum creatinine ≥50%; renal replacement therapy (RRT); and death in the pre-transplant, peri-transplant, and post-transplant periods.

RESULTS

74 patients were studied (7 heart transplants, 34 liver transplants, and 33 lung transplants). Patients who were not followed-up by a nephrologist in the pre-transplant (p < 0.027) or peri-transplant (p < 0.046) periods and those who had the longest time until an outpatient clinic follow-up (HR 1.032) were associated with a higher risk of creatinine increase ≥50%. Receiving a lung transplant conferred a higher risk than a liver or heart transplant for developing a creatinine increase ≥50% and ESKD. Peri-transplant mechanical ventilation, peri-transplant and post-transplant anticalcineurin overdose, nephrotoxicity, and the number of hospital admissions were significantly associated with a creatinine increase ≥50% and developing ESKD.

CONCLUSIONS

Early and close follow-up by a nephrologist was associated with a decrease in the worsening of renal function.

Kidney Podocyte Zebra Bodies after Lung Transplantation for Lymphangioleiomyomatosis

A 55-year-old woman showed progressive renal dysfunction after unilateral deceased-donor lung transplantation for lymphangioleiomyomatosis. A kidney biopsy showed a striped pattern of interstitial fibrosis, suggesting calcineurin inhibitor toxicity, and zebra body accumulation was found predominantly in the podocytes, characteristics of Fabry disease. Nevertheless, she had no extra-renal symptoms of the disease, and gene testing identified no known mutation or exon deletion. Our case report and literature review suggest that this atypical lysosomal inclusion may be phospholipidosis induced by sertraline. Potential underlying etiologies linking zebra body deposits may be not only hereditary but also drug-induced phospholipidosis.

Chronic kidney disease after lung transplantation in a changing era

Lung transplant (LTx) physicians are responsible for highly complex post-LTx care, including monitoring of kidney function and responding to kidney function loss. Better survival of the LTx population and changing patient characteristics, including older age and increased comorbidity, result in growing numbers of LTx patients with chronic kidney disease (CKD). CKD after LTx is correlated with worse survival, decreased quality of life and high costs. Challenges lie in different aspects of post-LTx renal care. First, serum creatinine form the basis for estimating renal function, under the assumption that patients have stable muscle mass. Low or changes in muscle mass is frequent in the LTx population and may lead to misclassification of CKD. Second, standardizing post-LTx monitoring of kidney function and renal care might contribute to slow down CKD progression. Third, new treatment options for CKD risk factors, such as diabetes mellitus, proteinuria and heart failure, have entered clinical practice. These new treatments have not been studied in LTx yet but are of interest for future use. In this review we will address the difficult aspects of post-LTx renal care and evaluate new and promising future approaches to slow down CKD progression.

Kidney disease in non-kidney solid organ transplantation

Kidney disease after non-kidney solid organ transplantation (NKSOT) is a common post-transplant complication associated with deleterious outcomes. Kidney disease, both acute kidney injury and chronic kidney disease (CKD) alike, emanates from multifactorial, summative pre-, peri- and post-transplant events. Several factors leading to kidney disease are shared amongst solid organ transplantation in addition to distinct mechanisms unique to individual transplant types. The aim of this review is to summarize the current literature describing kidney disease in NKSOT. We conducted a narrative review of pertinent studies on the subject, limiting our search to full text studies in the English language. Kidney disease after NKSOT is prevalent, particularly in intestinal and lung transplantation. Management strategies in the peri-operative and post-transplant periods including proteinuria management, calcineurin-inhibitor minimization/ sparing approaches, and nephrology referral can counteract CKD progression and/or aid in subsequent kidney after solid organ transplantation. Kidney disease after NKSOT is an important consideration in organ allocation practices, ethics of transplantation. Kidney disease after SOT is an incipient condition demanding further inquiry. While some truths have been revealed about this chronic disease, as we have aimed to describe in this review, continued multidisciplinary efforts are needed more than ever to combat this threat to patient and allograft survival.

De novo lupus-like glomerulonephritis after pediatric non-kidney organ transplantation

BACKGROUND

We propose a novel clinically significant finding, de novo lupus-like glomerulonephritis (DNLLGN), in patients with autoantibodies and kidney abnormalities in pediatric liver transplant (LT) and intestinal inclusive transplants (ITx).

METHODS

We describe the clinical, serologic, and histopathologic presentation and kidney outcomes in eight patients from our center found to have DNLLGN on kidney biopsy.

RESULTS

Pediatric recipients of non-kidney solid organ transplants developed an unusual de novo immune complex glomerulonephritis with morphologic similarity to lupus nephritis. Six had isolated LT (0.9% of all pediatric LT at our center) and two had ITx (2.1% of all ITx). Five (63%) presented with nephrotic syndrome. Five patients had autoantibodies. Patients underwent kidney biopsy at a mean of 11.5 years in LT and 2.8 years in ITx after the index transplant. Biopsies demonstrated changes similar to focal or diffuse active lupus. Follow-up eGFR at a mean of 6 years after biopsy showed a mean decrease of 30 ml/min/1.73 m² in all patients (p = 0.11).

CONCLUSIONS

DNLLGN has not been previously recognized in this clinical setting, yet 8 kidney biopsies from pediatric recipients of LT and ITx at our center in 25 years demonstrated this finding. DNLLGN appears to be an under-reported phenomenon of clinical significance. A higher resolution version of the Graphical abstract is available as Supplementary information.

CKD in Recipients of Nonkidney Solid Organ Transplants: A Review

Chronic kidney disease (CKD) after solid organ transplant is a common clinical presentation, affecting 10% to 20% of liver, heart and lung transplant recipients and accounting for approximately 5% of the kidney transplant waiting list. The causes of CKD are different for different types of transplants and are not all, or even predominantly, due to calcineurin inhibitor toxicity, with significant heterogeneity particularly in liver transplant recipients. Many solid organ transplant recipients with advanced CKD benefit from kidney transplantation, but have a higher rate of death while waitlisted and higher mortality following transplant than the general kidney failure population. Recent organ allocation policies and proposals have attempted to address the appropriate identification and prioritization of candidates in need of a kidney transplant, either simultaneous with or following non-kidney transplant. Future research should focus on predictive factors for individuals identified at high risk for progression to kidney failure and death, and strategies to preserve kidney function and minimize the CKD burden in this unique patient population.

Native BK virus nephropathy in lung transplant: a case report and literature review

Classically described in renal allografts, BK virus nephropathy is increasingly recognized in native kidneys of other non-renal solid organ transplants. We discuss a 68-year-old woman with a history of bilateral lung transplant referred for worsening renal function, confirmed to have BK virus nephropathy by biopsy with a serum BK virus polymerase chain reaction of over 59 million copies/mL. She was managed with a reduction in immunosuppression and intravenous cidofovir with no improvement in her clinical parameters. The seven prior reported cases of polyoma virus nephropathy in lung transplant recipients are reviewed, and the challenges of screening and management are discussed.

Kidney Disease After Nonkidney Solid Organ Transplant

Nonkidney solid organ transplants (NKSOTs) are increasing in the United States with improving long-term allograft and patient survival. CKD is prevalent in patients with NKSOT and is associated with increased morbidity and mortality especially in those who progress to end-stage kidney disease. Calcineurin inhibitor nephrotoxicity is a main contributor to CKD after NKSOT, but other factors in the pretransplant, peritransplant, and post-transplant period can predispose to progressive kidney dysfunction. The management of CKD after NKSOT generally follows society guidelines for native kidney disease. Kidney-protective and calcineurin inhibitor-sparing immunosuppression has been explored in this population and warrants a discussion with transplant teams. Kidney transplantation in NKSOT recipients remains the kidney replacement therapy of choice for suitable candidates, as it provides a survival benefit over remaining on dialysis.

Chronic Kidney Allograft Disease: New Concepts and Opportunities

Chronic kidney disease (CKD) is increasing in most countries and kidney transplantation is the best option for those patients requiring renal replacement therapy. Therefore, there is a significant number of patients living with a functioning kidney allograft. However, progressive kidney allograft functional deterioration remains unchanged despite of major advances in the field. After the first post-transplant year, it has been estimated that this chronic allograft damage may cause a 5% graft loss per year. Most studies focused on mechanisms of kidney graft damage, especially on ischemia-reperfusion injury, alloimmunity, nephrotoxicity, infection and disease recurrence. Thus, therapeutic interventions focus on those modifiable factors associated with chronic kidney allograft disease (CKaD). There are strategies to reduce ischemia-reperfusion injury, to improve the immunologic risk stratification and monitoring, to reduce calcineurin-inhibitor exposure and to identify recurrence of primary renal disease early. On the other hand, control of risk factors for chronic disease progression are particularly relevant as kidney transplantation is inherently associated with renal mass reduction. However, despite progress in pathophysiology and interventions, clinical advances in terms of long-term kidney allograft survival have been subtle. New approaches are needed and probably a holistic view can help. Chronic kidney allograft deterioration is probably the consequence of damage from various etiologies but can be attenuated by kidney repair mechanisms. Thus, besides immunological and other mechanisms of damage, the intrinsic repair kidney graft capacity should be considered to generate new hypothesis and potential therapeutic targets. In this review, the critical risk factors that define CKaD will be discussed but also how the renal mechanisms of regeneration could contribute to a change chronic kidney allograft disease paradigm.

Effects of mTOR inhibitor-related proteinuria on progression of cardiac allograft vasculopathy and outcomes among heart transplant recipients

We have previously described the use of sirolimus (SRL) as primary immunosuppression following heart transplantation (HT). The advantages of this approach include attenuation of cardiac allograft vasculopathy (CAV), improvement in glomerular filtration rate (GFR), and reduced malignancy. However, in some patients SRL may cause significant proteinuria. We sought to investigate the prognostic value of proteinuria after conversion to SRL. CAV progression and adverse clinical events were studied. CAV progression was assessed by measuring the Δ change in plaque volume (PV) and plaque index (PI) per year using coronary intravascular ultrasound. Proteinuria was defined as Δ urine protein ≥300 mg/24 h at 1 year after conversion to SRL. Overall, 137 patients were analyzed (26% with proteinuria). Patients with proteinuria had significantly lower GFR (P = .005) but similar GFR during follow-up. Delta PV (P < .001) and Δ PI (P = .001) were significantly higher among patients with proteinuria after adjustment for baseline characteristics. Multivariate Cox regression analysis showed higher all-cause mortality (hazard ratio 3.8; P = .01) with proteinuria but similar risk of CAV-related events (P = .61). Our results indicate that proteinuria is a marker of baseline renal dysfunction, and that HT recipients who develop proteinuria after conversion to SRL have less attenuation of CAV progression and higher mortality risk.

Clinical Relevance of Kidney Biopsy in Patients Qualified for Liver Transplantation and After This Procedure in the Model for End-stage Liver Disease (MELD) Era: Where Are We Today?

Chronic kidney disease (CKD) has been recognized as an increasingly common complication of liver transplantation (OLTx). Post-transplant renal dysfunction contributes to long-term morbidity and mortality following OLTx and is a very important issue in the management of liver transplant recipients. Its etiology is multifactorial and can be determined by kidney biopsy, which is too rarely done in this patient group. In the clinical context of patients with liver cirrhosis, accurate and reliable evaluation of the renal injury is crucial. We performed a review of kidney biopsies in patients with symptoms of CKD (proteinuria/hematuria/elevated creatinine) before and after liver transplantation in the published literature. Kidney biopsies were performed either before or after liver transplantation using percutaneous technique. There are few reports on transjugular kidney biopsy. Biopsy results prevented unnecessary modification of immunosuppressive therapy or selection of candidates for liver transplantation. In our opinion, kidney biopsy is a clinically relevant diagnostic approach to recognize kidney disease before and after liver transplantation, it also helps with the management of kidney disease in this population, and it is safe. Kidney biopsy should be offered more often in liver transplant patients to ensure appropriate therapy in concomitant CKD in this population. Our decisions today will impact clinical outcomes in the future.

Proteomic Characterization of Urinary Extracellular Vesicles from Kidney-Transplanted Patients Treated with Calcineurin Inhibitors

Use of immunosuppressive drugs is still unavoidable in kidney-transplanted patients. Since their discovery, calcineurin inhibitors (CNI) have been considered the first-line immunosuppressive agents, in spite of their known nephrotoxicity. Chronic CNI toxicity (CNIT) may lead to kidney fibrosis, a threatening scenario for graft survival. However, there is still controversy regarding CNIT diagnosis, monitoring and therapeutic management, and their specific effects at the molecular level are not fully known. Aiming to better characterize CNIT patients, in the present study, we collected urine from kidney-transplanted patients treated with CNI who (i) had a normal kidney function, (ii) suffered CNIT, or (iii) presented interstitial fibrosis and tubular atrophy (IFTA). Urinary extracellular vesicles (uEV) were enriched and the proteome was analyzed to get insight into changes happening during CNI. Members of the uroplakin and plakin families were significantly upregulated in the CNIT group, suggesting an important role in CNIT processes. Although biomarkers cannot be asserted from this single pilot study, our results evidence the potential of uEV as a source of non-invasive protein biomarkers for a better detection and monitoring of this renal alteration in kidney-transplanted patients.

Acute and chronic kidney disease after pediatric liver transplantation: An underestimated problem

Acute and chronic kidney injuries represent critical issues after liver transplantation (LTx), but whereas renal dysfunction in adult transplant patients is well documented, little is known about its prevalence in childhood. It is a challenge to accurately evaluate renal function in patients with liver disease, due to several confounding factors. Creatinine-based equations estimating glomerular filtration rate, validated in nephropathic patients without hepatic issues, are frequently inaccurate in end-stage liver disease, underestimating the real impact of renal disease. Moreover, whereas renal issues observed within 1 year from LTx were often related to acute injuries, kidney damage observed after 5-7 years from LTx, is due to chronic, irreversible mechanisms. Most immunosuppression protocols are based on calcineurin inhibitors (CNIs) and corticosteroids, but mycophenolate mofetil or sirolimus could play significant roles, also in children. Early diagnosis and personalized treatment represent the bases of kidney disease management, in order to minimize its close relation with increased mortality. This review analyzed acute and chronic kidney damage after pediatric LTx, also discussing the impact of pre-existent renal disease. The main immunosuppressant strategies have been reviewed, highlighting their impact on kidney function. Different methods assessing renal function were reported, with the potential application of new renal biomarkers.

Long-Term Outcomes and Risk Factors of Renal Failure Requiring Dialysis after Heart Transplantation: A Nationwide Cohort Study

Acute kidney injury and renal failure are common after heart transplantation. We retrospectively reviewed a national cohort and identified 1129 heart transplant patients. Patients receiving renal replacement therapy after heart transplantation were grouped into the dialysis cohort. The long-term survival and risk factors of dialysis were investigated. Patients who had undergone dialysis were stratified to early or late dialysis for subgroup analysis. The mean follow-up was five years, the incidence of dialysis was 28.4% (21% early dialysis and 7.4% late dialysis). The dialysis cohort had higher overall mortality compared with the non-dialysis cohort. The hazard ratios of mortality in patients with dialysis were 3.44 (95% confidence interval (CI), 2.73–4.33) for all dialysis patients, 3.58 (95% CI, 2.74–4.67) for early dialysis patients, and 3.27 (95% CI, 2.44–4.36; all p < 0.001) for late dialysis patients. Patients with diabetes mellitus, chronic kidney disease, acute kidney injury, and coronary artery disease were at higher risk of renal failure requiring dialysis. Cardiomyopathy, hepatitis B virus infection, and hyperlipidemia treated with statins were associated with a lower risk of renal dysfunction requiring early dialysis. The use of Sirolimus and Mycophenolate mofetil was associated with a lower incidence of late dialysis. Renal dysfunction requiring dialysis after heart transplantation is common in Taiwan. Early and late dialysis were both associated with an increased risk of mortality in heart transplant recipients.

Effectiveness and Nephrotoxicity of Long-Term Tacrolimus Administration in Patients with Ulcerative Colitis

BACKGROUND

Tacrolimus (TAC) is used for the management of ulcerative colitis (UC). However, there are few reports on the effectiveness of its long-term administration. TAC is also known to cause renal toxicity. The aim of this study was to evaluate long-term effectiveness and monitor changes in renal function during prolonged TAC use in patients with UC.

METHODS

Medical records of 50 UC patients treated with TAC were retrospectively reviewed. Clinical outcomes were assessed at 6, 12, 24, and 36 months after initiating TAC. We also monitored chronological changes in renal function.

RESULTS

Thirty-nine patients were treated with TAC for more than 3 months. Relapse-free survival among these patients at 6, 12, 24, and 36 months was 82%, 69%, 41%, and 23%, respectively. On the other hand, renal function was reduced in 35.9% of patients. We found that irreversible renal dysfunction was more likely to occur in cases in which the estimated glomerular-filtration rate (eGFR) was reduced by more than 30%.

CONCLUSION

This study demonstrated the potential use of TAC as an effective option in the long-term medical management of UC, although it tended to increase the risk of nephrotoxicity. There is a need for the careful monitoring of renal function during TAC administration.

Discovery and Validation of a Biomarker Model (PRESERVE) Predictive of Renal Outcomes After Liver Transplantation

BACKGROUND AND AIMS

A high proportion of patients develop chronic kidney disease (CKD) after liver transplantation (LT). We aimed to develop clinical/protein models to predict future glomerular filtration rate (GFR) deterioration in this population.

APPROACH AND RESULTS

In independent multicenter discovery (CTOT14) and single-center validation (BUMC) cohorts, we analyzed kidney injury proteins in serum/plasma samples at month 3 after LT in recipients with preserved GFR who demonstrated subsequent GFR deterioration versus preservation by year 1 and year 5 in the BUMC cohort. In CTOT14, we also examined correlations between serial protein levels and GFR over the first year. A month 3 predictive model was constructed from clinical and protein level variables using the CTOT14 cohort (n = 60). Levels of β-2 microglobulin and CD40 antigen and presence of hepatitis C virus (HCV) infection predicted early (year 1) GFR deterioration (area under the curve [AUC], 0.814). We observed excellent validation of this model (AUC, 0.801) in the BUMC cohort (n = 50) who had both early and late (year 5) GFR deterioration. At an optimal threshold, the model had the following performance characteristics in CTOT14 and BUMC, respectively: accuracy (0.75, 0.8), sensitivity (0.71, 0.67), specificity (0.78, 0.88), positive predictive value (0.74, 0.75), and negative predictive value (0.76, 0.82). In the serial CTOT14 analysis, several proteins, including β-2 microglobulin and CD40, correlated with GFR changes over the first year.

CONCLUSIONS

We have validated a clinical/protein model (PRESERVE) that early after LT can predict future renal deterioration versus preservation with high accuracy. This model may help select recipients at higher risk for subsequent CKD for early, proactive renal sparing strategies.

Non-respiratory complaints are main reasons for disturbed sleep post lung transplant

BACKGROUND

Poor sleep is prevalent in lung transplant recipients and affects quality of life negatively. To improve quality of sleep, it's important to identify the causes of poor sleep. We conducted a survey to identify the reasons for poor sleep quality in the recipients.

METHODS

We surveyed lung transplant recipients (2003-2010) at Baylor College of Medicine/The Methodist Hospital lung transplant center. We used a compilation of questionnaires, including the Pittsburgh Sleep Quality Index (PSQI), Berlin Questionnaire, Epworth Sleepiness Scale (ESS) and Short Form 36 (SF36). Descriptive analysis was performed on the responses.

RESULTS

Of the 167 participants, 54 responded (32.3%) with mean age 60.6 years (SD 9.8), 48% male, and a mean post-transplant body mass index (BMI) of 27 (SD 4.7). The responders reported a long mean sleep latency of 33.2 min (SD 32.5), poor sleep quality (74% with PSQI score > 5), excessive daytime sleepiness (ESS > 9 in 29%), poor physical QOL with SF36 mean score of 41.3 (SD 9.4), and high risk for OSA (48.2%). About 30% and 72% reported sleep initiation and maintenance insomnia, respectively. The poor sleep quality was due to "getup to go to bathroom" (85%), "cough or snore loudly" (33%), "have pain" (27.8%), and "feel too cold" (27.8%). Furthermore, 5% reported "Can't breathe comfortably" as reason for poor sleep.

CONCLUSIONS

The recipients reported poor sleep and quality of life. The non-respiratory complaints were important factors for poor sleep. Attention to these factors may help to outline better management strategies to improve sleep in lung transplant recipients.

Effects of late cyclosporine withdrawal on renal graft function and survival

OBJECTIVE

Attempts to discontinue calcineurin inhibitors (CNIs) early after renal transplantation without conversion to an alternative immunosuppressive have failed due to high rates of acute rejection. Data on "late" CNI withdrawal are lacking so far.

DESIGN AND METHOD

We carried out a matched case-control study on the effects of CNI withdrawal on graft loss and mortality in 90 patients (1500 screened) with advanced graft dysfunction (serum creatinine > 3.5 mg/dl) and a cyclosporine-based triple immunosuppressive regimen at the Charité University Hospital, Berlin.

RESULTS

Cyclosporine was withdrawn at a mean of 54.0 ± 32.8 months post-transplant in 45 subjects. Whereas estimated glomerular filtration rate (eGFR) did not significantly differ between the groups at this time (12.4 ± 2.7 vs. 14.7 ± 8.9 in the control group, p = 0.08), it was significantly higher in subjects undergoing withdrawal after 120 months (Δ 4.1 ml/min; p < 0.001). In a Cox regression analysis adjusted for age, gender and eGFR, patients with CNI withdrawal showed better survival rates for the combined endpoint death/graft loss (hazard ratio, HR [95% confidence interval]: 0.19 [0.12-0.33], p = 0.001) compared to matched controls. The survival benefit was significant for the endpoints death (p = 0.01) and graft loss (p = 0.001).

CONCLUSIONS

CNI withdrawal was associated with improved survival rates in patients with advanced graft dysfunction in this retrospective analysis.

Does Mineralocorticoid Receptor Antagonism Prevent Calcineurin Inhibitor-Induced Nephrotoxicity?

Calcineurin inhibitors have markedly reduced acute rejection rates in renal transplantation, thus significantly improved short-term outcome. The beneficial effects are, however, tampered by acute and chronic nephrotoxicity leading to interstitial fibrosis and tubular atrophy, which impairs long-term allograft survival. The mineralocorticoid hormone aldosterone induces fibrosis in numerous organs, including the kidney. Evidence from animal models suggests a beneficial effect of aldosterone antagonism in reducing calcineurin inhibitor-induced nephrotoxicity. This review summarizes current evidence of mineralocorticoid receptor antagonism in animal models of calcineurin inhibitor-induced nephrotoxicity and the results from studies of mineralocorticoid antagonism in renal transplant patients.

Safety of Peritoneal Dialysis after Nonrenal Solid-Organ Transplantation

BACKGROUND

End-stage renal disease is a well-known complication after solid-organ transplantation, mostly as a result of calcineurin-inhibitor therapy. Among recipients of solid-organ transplants other than kidneys, peritoneal dialysis (PD) has been considered an accessory technique as an increased risk of infectious complications has been reported. The aim of our study was to evaluate the outcome of patients with a liver, heart, or lung transplant who underwent PD for replacement therapy.

METHODS

This was a retrospective, monocentric study. Every adult patient starting PD between January 1, 2001, and December 31, 2016, at our center was included. The history of previous solid-organ transplantation was determined. For the statistical analysis, we considered 2 groups of patients: 1 group having a history of transplantation of an organ other than the kidney (lung, heart, liver), and 1 group that was starting dialysis without any prior history of organ transplantation. Patients who had previously undergone kidney transplantation were excluded. The events of interest were the first peritonitis episode, death, and PD failure, defined as transfer to hemodialysis.

RESULTS

A total of 383 patients started PD during this period, 13 of whom had a history of organ transplantation. We found no significant difference between the solid-organ transplantation patients and those without a history of transplantation in terms of the occurrence of peritonitis (HR [hazard ratio] 0.91 [0.37 - 2.22]), death (HR 0.83 [0.26 - 2.63]), and PD failure (HR 1.01 [0.32 - 3.22]).

CONCLUSION

Peritoneal dialysis appears to be an effective replacement therapy for patients with a previous history of solid-organ transplantation.

Thrombotic Microangiopathy With Granulomatosis Interstitial Nephritis in an Allogenic Bone Marrow Transplant Patient: A Case Report and Review of the Literature

Transplant-associated thrombotic microangiopathy (TA-TMA) is a rare complication of hematopoietic stem cell transplantation (HSCT) with variable presentations. TA-TMA has often been described as a diagnosis of exclusion but a renal biopsy is rarely pursued to confirm the diagnosis, an essential step for our patient with renally limited TMA. We report a case report from the onconephrology clinic and review the literature associated with TA-TMA as it relates to diagnosis and treatment. A 45-year-old woman with acute myeloid leukemia and stage 3 chronic kidney disease underwent a matched unrelated donor allogenic HSCT. Postoperatively, she developed gastrointestinal graft versus host disease (GvHD) and was treated with tacrolimus, sirolimus, budesonide, and beclomethasone. Following discharge, she developed uncontrolled hypertension and required losartan, amlodipine, carvedilol, clonidine patch, and hydralazine as needed. On day 180 post-transplant, she developed lower extremity edema and acute kidney injury (AKI) with creatinine increasing to 2 mg/dL. On day 480 post-transplant, she developed worsening thrombocytopenia, anemia, new hematuria, left flank pain, and worsening renal function with creatinine peaking to 6 mg/dL. Peripheral smear revealed no schistocytes, lactate dehydrogenase of 265 mg/dL, and urinalysis with 100 mg/dL protein. ADAMTS 13 activity was normal (92%) and no inhibitor was detected. She became anuric and was started on hemodialysis. Renal biopsy revealed glomerular changes consistent with TA-TMA. During HSCT, systemic vascular endothelial injury triggers microangiopathic hemolytic anemia, platelet consumption, injury of glomerular endothelial cells and fibrin occluded renal capillaries. Thus, TA-TMA should be considered in HSCT patients with elevated LDH, proteinuria, hypertension, and AKI. However, a diagnosis is difficult to confirm without a renal biopsy. Treatment involves discontinuing potentially toxic agents such as calcineurin inhibitors and sirolimus, prescribing adequate antimicrobial treatment, and using renal replacement therapy if needed. A renal biopsy early in the course of disease not only confirms the diagnosis, but may limit the extent of disease.

Outcomes of Pediatric Kidney Transplantation in Recipients of a Previous Non-Renal Solid Organ Transplant

Children who receive a non-renal solid organ transplant may develop secondary renal failure requiring kidney transplantation. We investigated outcomes of 165 pediatric kidney transplant recipients who previously received a heart, lung, or liver transplant using data from 1988 to 2012 reported to the United Network for Organ Sharing. Patient and allograft survival were compared with 330 matched primary kidney transplant (PKT) recipients. Kidney transplantation after solid organ transplant (KASOT) recipients experienced similar allograft survival: 5- and 10-year graft survival was 78% and 60% in KASOT recipients, compared to 80% and 61% in PKT recipients (p = 0.69). However, KASOT recipients demonstrated worse 10-year patient survival (75% KASOT vs. 97% PKT, p < 0.001). Competing risks analysis indicated that KASOT recipients more often experienced graft loss due to patient death (p < 0.001), whereas allograft failure per se was more common in PKT recipients (p = 0.01). To study more recent outcomes, kidney transplants performed from 2006 to 2012 were separately investigated. Since 2006, KASOT and PKT recipients had similar 5-year graft survival (82% KASOT vs. 83% PKT, p = 0.48), although 5-year patient survival of KASOT recipients remained inferior (90% KASOT vs. 98% PKT, p < 0.001). We conclude that despite decreased patient survival, kidney allograft outcomes in pediatric KASOT recipients are comparable to those of PKT recipients.

Comprehensive Care of the Lung Transplant Patient

Lung transplantation has evolved into a life-saving treatment with improved quality of life for patients with end-stage respiratory failure unresponsive to other medical or surgical interventions. With improving survival rates, the number of lung transplant recipients with preexisting and posttransplant comorbidities that require attention continues to increase. A partnership between transplant and nontransplant care providers is necessary to deliver comprehensive and optimal care for transplant candidates and recipients. The goals of this partnership include timely referral and assistance with transplant evaluation, optimization of comorbidities and preparation for transplantation, management of common posttransplant medical comorbidities, immunization, screening for malignancy, and counseling for a healthy lifestyle to maximize the likelihood of a good outcome. We aim to provide an outline of the main aspects of the care of candidates for and recipients of lung transplants for nontransplant physicians and other care providers.

Kidney transplant recipients after nonrenal solid organ transplantation show low alloreactivity but an increased risk of infection

The number of kidney transplant recipients (KTRs) after nonrenal solid organ transplantation (SOT) has increased to almost 5%. Knowledge on patient and allograft outcomes, infections, and alloreactivity, however, remains scarce. We studied 40 KTRs after nonrenal SOT. Seven hundred and twenty primary KTRs and 119 repeat KTRs were used for comparison. Samples were collected pretransplantation, at +1, +2, and +3 months post-transplantation. Alloreactive and CMV-specific T cells were measured by interferon-γ ELISPOT assay. Patient survival in KTRs after SOT, primary and repeat KTRs was comparable. While death-censored allograft survival was comparable between KTRs after SOT and primary KTRs, KTRs after SOT showed superior 5-year death-censored allograft survival of 92.5% compared to 81.2% in repeat KTRs. Interestingly, KTRs after SOT show less preformed panel-reactive antibodies, frequencies of alloreactive T cells, and acute rejections compared to repeat KTRs. KTRs after SOT, however, show higher incidences of EBV viremia and PTLD, sepsis, and death from sepsis. Impaired CMV-specific cellular immunity was associated with more CMV replication compared to repeat KTRs. Our results suggest comparable patient and allograft outcomes in KTRs after SOT and primary KTRs. The observed low alloreactivity may contribute to excellent allograft outcomes. Caution should be taken in KTRs after SOT regarding infectious complications due to overimmunosuppression.

Acute Kidney Disease After Liver and Heart Transplantation

After transplantation of nonrenal solid organs, an acute decline in kidney function develops in the majority of patients. In addition, a significant number of nonrenal solid organ transplant recipients develop chronic kidney disease, and some develop end-stage renal disease, requiring renal replacement therapy. The incidence varies depending on the transplanted organ. Acute kidney injury after nonrenal solid organ transplantation is associated with prolonged length of stay, cost, increased risk of death, de novo chronic kidney disease, and end-stage renal disease. This overview focuses on the risk factors for posttransplant acute kidney injury after liver and heart transplantation, integrating discussion of proteinuria and chronic kidney disease with emphasis on pathogenesis, histopathology, and management including the use of mechanistic target of rapamycin inhibition and costimulatory blockade.

Renal pathology in hematopoietic cell transplant recipients: a contemporary biopsy, nephrectomy, and autopsy series

Renal injury in hematopoietic cell transplant recipients may be related to a combination of factors including chemotherapy, radiation, infection, immunosuppressive agents, ischemia, and graft-versus-host disease, and can involve glomerular, tubulointerstitial, and vascular structures. We reviewed renal pathology from 67 patients at a single institution (2009-2014), including 14 patients with biopsy for clinical dysfunction, 6 patients with surgical kidney resection for other causes, and 47 autopsy patients. Kidney specimens frequently contained multiple histopathologic abnormalities. Thrombotic microangiopathy, membranous nephropathy, minimal change disease, and focal segmental glomerulosclerosis were the most common glomerular findings. Pathologies not previously reported in the hematopoietic cell transplant setting included collapsing glomerulopathy, antiglomerular basement membrane disease, fibrillary glomerulonephritis, and in the case of two surgical resections distinctive cellular segmental glomerular lesions that defied classification. Kidney specimens frequently demonstrated acute tubular injury, interstitial fibrosis, arteriolar hyaline, and arteriosclerosis. Other kidney findings at autopsy included leukemia and amyloid (both recurrent), diabetic nephropathy, bacterial infection, fungal invasion, and silver deposition along glomerular and tubular basement membranes. Also in the autopsy cohort, C4d immunohistochemistry demonstrated unexpected membranous nephropathy in two patients, yet C4d also colocalized with arteriolar hyaline. This retrospective hematopoietic cell transplant cohort illustrates multifaceted renal injury in patients with renal dysfunction, as well as in patients without clinically recognized kidney injury.

Recurrence of diabetic kidney disease in a type 1 diabetic patient after kidney transplantation

Post-transplant hyperglycaemia of diabetic patients may cause recurrent diabetic kidney disease (DKD) in kidney allografts. We report a patient with slowly progressive DKD with calcineurin inhibitor toxicity (CNI) toxicity after the kidney transplantation. A 28-year-old female with type 1 diabetes mellitus underwent successful kidney transplantation from her mother in April 2003, and the kidney graft survived for more than 10 years. She was treated with combined immunosuppressive therapy consisting of cyclosporine and mycophenolate mofetil. After transplantation, she continued to take insulin injection four times per day, but her glycosylated haemoglobin (HbA1c) was above 10%. Protocol allograft kidney biopsies performed 5 and 10 years after transplantation revealed the recurrence of slowly progressive diabetic kidney disease. In addition, arteriolar hyalinosis partly associated with calcineurin inhibitor toxicity (CNI) was detected with progression. Post-transplant hyperglycaemia causes recurrent diabetic kidney disease (DKD) in kidney allografts, but its progression is usually slow. For long-term management, it is important to prevent the progression of the calcineurin inhibitor arteriolopathy, as well as maintain favourable glycaemic control.

The Effect of Mammalian Target of Rapamycin Versus Calcineurin Inhibitor-based Immunosuppression on Measured Versus Estimated Glomerular Filtration Rate After Orthotopic Liver Transplantation

INTRODUCTION

Mammalian target of rapamycin (mTOR) inhibitors have been proposed to preserve renal function in patients after orthotopic liver transplantation (OLT) based on estimated glomerular filtration rate (eGFR). The presented study evaluated their effect on renal function in comparison to calcineurin inhibitors (CNIs) defined by measured GFR.

METHODS

Renal function was measured in patients on mTOR-based (n=28) or on CNI-based (n=51) immunosuppression after OLT by performing inulin clearance (IC) as well as eGFR based on the Modification of Diet in Renal Disease (MDRD4) Study and the chronic kidney disease epidermiology (CKD-EPI) formula at baseline, 6, 12, 18, and 24 months. Statistical analysis was performed by using analysis of variance and serial measurement testing.

RESULTS

The MDRD4 and the IC values differed significantly at study inclusion in both groups (mTOR and CNI group, P=0.001), whereas the CKD-EPI and the IC values did not. Estimated GFR by the MDRD4 results declined throughout the study period in patients on CNI and in patients on mTOR (CNI, 81 vs. 61 mL/min/1.73 m(2), P=0.01; 82 vs. 60 mL/min/1.73 m(2), P=0.01), whereas CKD EPI and measured GFR did not change throughout the study period in the CNI.

CONCLUSION

The use of eGFR especially the MDRD-based formula, in OLT patients, leads to incorrect interpretation of their renal function.

Sirolimus conversion after heart transplant: risk factors for acute rejection and predictors of renal function response

In a randomized, comparative study of cardiac transplant patients with mild-to-moderate renal insufficiency, conversion from calcineurin inhibitors (CNIs) to sirolimus improved renal function at 1 year versus continuing CNIs, with an attendant risk of biopsy-confirmed acute rejection (BCAR). Post hoc analyses were conducted to identify predictors of BCAR and GFR improvement associated with conversion. Patients with proteinuria >500 mg/day were excluded. Univariate and multivariate regression analyses tested 13 parameters for BCAR and six for GFR improvement. In 57 sirolimus-treated patients, mean daily mycophenolate mofetil (MMF) dose was lower in those with versus without BCAR (1000 vs. 1420 mg; p = 0.014). Receiver operating characteristic analysis identified MMF dose ≤1000 mg/day as the optimal cutoff to predict BCAR. Multivariate analysis confirmed low MMF dose (odds ratio: 9.94; p = 0.007) and non-white race (odds ratio: 15.3; p = 0.06) were independently associated with BCAR. GFR improvement was evaluated in intent-to-treat patients (n = 116). Significant interaction was detected between treatment effect and preexisting diabetes status (univariate p = 0.077; multivariate p = 0.022), indicating greater beneficial effect of sirolimus in those without preexisting diabetes. These findings suggest that sirolimus is more effective in improving GFR in patients without preexisting diabetes, and adequate MMF doses are needed for sirolimus conversion.

Renal pathology associated with hematopoietic stem cell transplantation

The kidney is subject to a large variety of injurious factors before, during, and after hematopoietic stem cell transplantation (HCT), leading to a high incidence of acute kidney injury in the peritransplant period. Chronic kidney disease is estimated to impact 15% to 20% of HCT recipients. Although renal biopsies may be deferred in the setting of thrombotic microangiopathy, acute self-limited impairment, or slowly progressive functional decline, in many patients renal biopsy yields important diagnostic insight to guide treatment. Light microscopic, immunofluorescence, and ultrastructural analysis often reveals a number of concurrent abnormalities in glomeruli, tubules, interstitium, and vessels. Meta-analysis of the literature reveals that membranous nephropathy is the most commonly reported glomerular lesion in the setting of HCT, followed by minimal change disease. Autopsy and biopsy studies show that clinical criteria lack sensitivity and specificity for renal acute and chronic thrombotic microangiopathy. Viral infection and other causes of interstitial nephritis and tubular injury are important findings in HCT renal biopsies, which in many instances may not be clinically suspected. Given the complexity and variability of HCT protocols, clinicopathologic correlation is needed.

Renal dysfunction in end-stage liver disease and post-liver transplant

Renal dysfunction is a frequent complication in patients with end-stage liver disease awaiting orthotopic liver transplantation and in the post-liver transplant period. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, other causes of acute kidney injury in this population include prerenal azotemia and acute tubular necrosis. Renal injury in a patient with cirrhosis is associated with a poor prognosis.

Diagnostic and risk criteria for HSCT-associated thrombotic microangiopathy: a study in children and young adults

Transplant-associated thrombotic microangiopathy (TMA) leads to generalized endothelial dysfunction that can progress to multiorgan injury, and severe cases are associated with poor outcomes after hematopoietic stem cell transplantation (HSCT). Identifying patients at highest risk for severe disease is challenging. We prospectively evaluated 100 consecutive HSCT recipients to determine the incidence of moderate and severe TMA and factors associated with poor overall outcomes. Thirty-nine subjects (39%) met previously published criteria for TMA. Subjects with TMA had a significantly higher nonrelapse mortality (43.6% vs 7.8%, P < .0001) at 1 year post-HSCT compared with those without TMA. Elevated lactate dehydrogenase, proteinuria on routine urinalysis, and hypertension were the earliest markers of TMA. Proteinuria (>30 mg/dL) and evidence of terminal complement activation (elevated sC5b-9) in the blood at the time of TMA diagnosis were associated with very poor survival (<20% at 1 year), whereas all TMA subjects without proteinuria and a normal sC5b-9 serum concentration survived (P < .01). Based on these prospective observations, we conclude that severe TMA occurred in 18% of HSCT recipients in our cohort and propose an algorithm to identify the highest-risk patients who might benefit from prompt clinical interventions.

The kidney effects of hematopoietic stem cell transplantation

Hematopoietic stem cell transplant (HSCT) patients are at risk for acute kidney disease and CKD, which confer excess morbidity and mortality in this patient population. A main cause of acute kidney injury (AKI) in stem cell recipients is prerenal azotemia, but acute tubular necrosis (ATN), obstruction, marrow transfusion toxicity, and hepatic sinusoidal obstruction syndrome also contribute. AKI is an important risk factor for death and CKD among HSCT survivors. CKD is a growing complication of HSCT as more patients are transplanted and survival improves. For most patients, the exact etiology of CKD is never identified, but graft vs host disease and thrombotic microangiopathy are important diagnoses to consider. Stem cell transplant patient survival on dialysis is generally poor, but kidney transplantation is a safe and reasonable option for HSCT recipients who progress to ESRD.

Renal function and histology in children after small bowel transplantation

CKD is a frequent long-term complication after SBTx. CNIs are a well-known factor, but probably not the only cause. We assessed the incidence, risk factors, and severity of CKD in 27 children with SBTx (15 combined liver/SBTx) and prednisone/TAC-based maintenance immunosuppression. Median follow-up was seven yr (3-21). A renal biopsy was performed in 14 patients, 1-18 yr post-SBTx. A reduced GFR was observed in 17 children (63%) during the follow-up with none requiring dialysis. CNI toxicity was observed in 11/14 biopsies, as early as two yr post-transplant, and could occur with a normal mGFR. The dose of TAC was reduced by 50% in 13 patients with CKD and/or significant kidney histological lesions, and six were also given MMF. This led to a significant improvement in renal function: mGFR normalized in eight patients and improved or stabilized in five. No rejection occurred. At last follow-up, 37% had CKD stage 2 and 15% had CKD stage 3. In conclusion, CKD is frequent in children after SBTx and probably multifactorial. Less nephrotoxic immunosuppressive protocols may improve mGFR and should be further considered. The kidney histology helps in designing personalized immunosuppression strategies for patients.

Kidney complications of hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) exposes a patient's kidneys to a unique combination of challenges, including high-dose radiation, anemia, chemotherapeutic agents, graft-versus-host disease, opportunistic infections, attenuated and altered immunologic responses, fluid and electrolyte imbalances, and extensive courses of antimicrobial agents. Since the inception of HSCT in the 1950s, there has been increasing interest in defining, determining, and managing the kidney complications that accompany this procedure. In this article, we review the common causes of acute kidney injury and chronic kidney disease that occur with HSCT, including HSCT-associated thrombotic microangiopathy, a distinct cause of chronic kidney disease with a multifactorial cause previously known as bone marrow transplant nephropathy or radiation nephropathy. Additionally, we review other kidney complications, including calcineurin inhibitor nephrotoxicity and chronic graft-versus-host disease-associated glomerulonephritis, that develop post-HSCT. Critically, due to its grave prognosis, it is important to identify HSCT-associated thrombotic microangiopathy early, as well as distinguish it from the other causes of chronic kidney disease.

BK polyoma virus nephropathy in the native kidney

BACKGROUND

While BK polyoma virus nephropathy (PVN) is a well-recognized cause of renal allograft dysfunction, PVN of native kidneys is likely under-recognized.

METHODS

We present the pathologic features, risk factors and outcomes of eight cases of PVN in native kidneys.

RESULTS

The cohort included eight males aged 16-73 years (mean 47.4) with an immunocompromised state (mean duration 3.15 years) attributable to: hematologic malignancies (n = 6), for which three had undergone bone marrow transplant; lung transplant (n = 1) and combined tuberculosis and diabetes (n = 1). Seven patients were receiving specific immunosuppressive therapies. Patients were biopsied for acute kidney injury (AKI) with rise in mean creatinine levels from baseline 1.6 to 2.8 mg/dL. Pathology showed BK PVN with characteristic intranuclear inclusions staining positive for SV40 T antigen and negative for JC virus (JCV), with positive serum and/or urine PCR for BK virus. One patient had focal medullary JCV co-infection. Two patients also had renal infiltration by chronic lymphocytic leukemia (CLL). Six patients received specific therapy directed to PVN (cidofovir or leflunomide). Follow-up ranged from 2 to 20 (mean 10) months. Despite marked decrease in serum BK viral copy numbers, creatinine continued to rise in six cases (mean 3.7 mg/dL in four, requiring dialysis in two) and three patients died of malignancy, opportunistic infection or renal failure. Advanced histologic stage of PVN, ineffective antiviral therapy, co-morbidities and persistent immunocompromised state likely contributed to the poor outcomes.

CONCLUSION

A high level of suspicion in immunocompromised patients is needed to diagnose PVN in an early stage that may respond more favorably to antiviral therapy.