Kidney disease after heart and lung transplantation

Long-term follow-up of the randomized, prospective Scandinavian heart transplant everolimus de novo study with early calcineurin inhibitors avoidance (SCHEDULE) trial

BACKGROUND

Early substitution of calcineurin inhibitor (CNI) with mammalian target of rapamycin inhibitors has been shown to improve kidney function and reduce intimal hyperplasia in heart transplant (HTx) recipients but data on long-term outcome of such a regime are still sparse.

METHODS

In the SCHEDULE trial, 115 de novo HTx recipients were randomized to (1) everolimus with reduced exposure of CNI followed by CNI withdrawal at week 7-11 post-transplant or (2) standard-exposure with CNI. Both groups received mycophenolate mofetil and corticosteroids. Herein we report on the 10-12-year long-term follow-up of the study.

RESULTS

A total of 78 patients attended the follow-up visit at a median time of 11 years post-transplant. In the everolimus intention to treat (ITT) group 87.5% (35/40 patients) still received everolimus and in the CNI ITT group 86.8% (33/38) still received CNI. Estimated glomerular filtration rate (eGFR) (least square mean (95% CI)) at the 10-12 years visit was 82.7 (74.2-91.1) ml/min/1.73 m2 and 61.0 (52.3-69.7) ml/min/1.73 m2 in the everolimus and CNI group, respectively (p < 0.001). Graft function measured by ejection fraction, ECG, NT-proBNP and drug safety were comparable between groups. During the study period there was a total of 28 deaths, but there was no difference in survival between the everolimus and the CNI group (aHR 0.61 (95% CI 0.29-1.30) p = 0.20). For the composite endpoint of death, re-transplantation, myocardial infarction, PCI, dialysis, kidney transplantation or cancer no between group differences were found (aHR 1.0 (95% CI 0.57-1.77) p = 0.99).

CONCLUSIONS

De novo HTx patients randomized to everolimus and low dose CNI followed by CNI free therapy sustained significantly better long-term kidney function than patients randomized to standard therapy. The graft function at 10-12 years was similar in both groups and there was no difference in survival.

Updates in induction immunosuppression regimens for intestinal transplantation

Intestinal allografts are the most immunologically complex and carry the highest risk of rejection among solid organ transplantation, necessitating complex immunosuppressive management. We evaluated the latest information regarding induction immunosuppression, with an emphasis on established, novel, and emergent therapies. We also reviewed classic and novel induction immunosuppression strategies for highly sensitized recipients. Comparable progress has been made in intestinal transplantation clinical outcomes since the implementation of induction strategies. This review shows a clear diversity of induction protocols can be observed across different centers. The field of intestinal transplantation is still in its early stages, which is further complicated by the limited number of institutions capable of intestinal transplantation and their geographical variation, which further hinders the development of adequately powered studies in comparison to other organs. As the implementation of institution-specific induction protocols becomes more refined and results are disseminated, future research efforts should be directed towards the development of efficacious induction strategies.

Long-term outcomes of lung transplantation requiring renal replacement therapy: A single-center experience

BACKGROUND

Life-long immunosuppressive therapy after lung transplantation (LT) may lead to end-stage renal disease (ESRD), requiring renal replacement therapy (RRT). We aimed to investigate the characteristics and long-term outcomes of patients undergoing LT and requiring RRT.

METHODS

This study was a single-center, retrospective cohort study. The patients were divided into the RRT (n = 15) and non-RRT (n = 170) groups. We summarized the clinical features of patients in the RRT group and compared patient characteristics, overall survival, and chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

RESULTS

The cumulative incidences of ESRD requiring RRT after LT at 5, 10, and 15 years were 0.8 %, 7.6 %, and 25.2 %, respectively. In the RRT group, all 15 patients underwent hemodialysis but not peritoneal dialysis, and two patients underwent living-donor kidney transplantation. The median follow-up period was longer in the RRT group than in the non-RRT group (P < 0.001). The CLAD-free survival and overall survival did not differ between the two groups. The 5-year survival rate even after the initiation of hemodialysis was 53.3 %, and the leading cause of death in the RRT group was infection.

CONCLUSIONS

Favorable long-term outcomes can be achieved by RRT for ESRD after LT.

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.

Identification of genetic loci associated with renal dysfunction after lung transplantation using an ethnic-specific single-nucleotide polymorphism array

Renal dysfunction is a long-term complication associated with an increased mortality after lung transplantation (LT). We investigated the association of single-nucleotide polymorphisms (SNPs) with the development of renal dysfunction after LT using a Japanese-specific SNP array. First, eligible samples of 34 LT recipients were genotyped using the SNP array and divided into two groups, according to the presence of homozygous and heterozygous combinations of mutant alleles of the 162 renal-related SNPs. To identify candidate SNPs, the renal function tests were compared between the two groups for each SNP. Next, we investigated the association between the candidate SNPs and the time course of changes of the estimated glomerular filtration rate (eGFR) in the 99 recipients until 10 years after the LT. ΔeGFR was defined as the difference between the postoperative and preoperative eGFR values. Eight SNPs were identified as the candidate SNPs in the 34 recipients. Validation analysis of these 8 candidate SNPs in all the 99 recipients showed that three SNPs, namely, rs10277115, rs4690095, and rs792064, were associated with significant changes of the ΔeGFR. Pre-transplant identification of high-risk patients for the development of renal dysfunction after LT based on the presence of these SNPs might contribute to providing personalized medicine.

Benefit of Kidney Transplantation for Post Lung Transplantation Renal Failure

INTRODUCTION

Nephrotoxicity is a significant side effect of thoracic transplantation. Many lung transplant patients will require subsequent renal transplantation (KAL). Recently, simultaneous lung/kidney transplants (SLuK) have become an attractive option for patients with end-stage renal disease at the time of lung transplantation. This article explores SLuK outcomes compared to conventional KAL, as well as outcomes among KAL patients against those were KAL listed but never transplanted.

MATERIALS AND METHODS

The United Network for Organ Sharing/the Organ Procurement and Transportation Network database was used to identify SLuK patients (n = 74), KAL transplants (n = 456), and patients who were listed for KAL but were never transplanted (n = 626). Significance was determined by chi², Wilcoxon rank sum test, or independent t-tests. Death-censored graft survival for subgroups was estimated using Kaplan-Meier with log-rank for significance. Analyses were completed using SPSS Statistics 28.

RESULTS

The SLuK cohort was older (P = 0.04), more likely diabetic (P < 0.001), and had shorter life expectancies (P < 0.001) than KAL patients. Of those SLuK transplants within 5 y, 84% of patients were alive 1 y post transplant and 82% were alive 3 y post-transplant (compared to 74.6% and 60.3% of overall SLuK). Patients who did undergo KAL were younger and had a lower body mass index (both P < 0.001) compared to those who did not. Those who received a kidney had increased survival times compared to WL patients (P < 0.001).

CONCLUSIONS

Conventional KAL transplants are still favorable for average lung recipients. However, recent improvements have made SLuK an option for patients with renal dysfunction. Those patients who were able to receive KAL transplants were better surgical candidates than those who remained on the waitlist.

The impact of long-term exposure to tacrolimus on chronic kidney disease after lung transplantation: A retrospective analysis from a single transplantation center

BACKGROUND

Chronic kidney disease (CKD) is a progressive and irreversible complication in lung transplant patients who have received long-term treatment with tacrolimus. This study aimed to verify long-term tacrolimus exposure values in CKD progression.

METHODS

We retrospectively analyzed the clinical data of adult lung transplant recipients performed at our center between 2012 and October 2015. Patients who completed the 5-year follow-up period were enrolled in this study. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m².

RESULTS

Eighty patients were analyzed. Compared with baseline (109 ± 38.1 mL/min/1.73 m2), the average eGFR values of our patients gradually decreased during the fifth-year post transplantation (46.5%, 58.3 ± 28.3 mL/min/1.73 m2), and the decline in eGFR values was particularly pronounced in the first year (31.2%, 74.6 ± 28.91 mL/min/1.73 m2). Moreover, 10 (12.7%), 21 (26.9%), 24 (31.2%), 28 (41.2%), and 48 (60%) patients had eGFR <60 mL/min/1.73 m² at 3, 6, 1, 3, and 5 years after lung transplantation (LT), respectively. A significant negative correlation was found between tacrolimus dose and eGFR 6 months after LT (P = 0.0414). We found no correlation between the serum tacrolimus concentration and CKD progression.

CONCLUSION

eGFR constantly decreased and the incidence of CKD increased during the 5-year follow-up period after LT. The tacrolimus dose had a significant negative correlation with eGFR at 6 months after LT. Meanwhile, whole-blood tacrolimus trough concentrations were not correlated with eGFR decline. When possible, lower dosing within 1 year after LT can reduce potential nephrotoxic side effects.

Risks and ways of preventing kidney dysfunction in drug-induced immunosuppression in solid organ recipients

Immunosuppressive therapy (IMT) is the cornerstone of treatment after transplantation. The goal of immunosuppression is to prevent acute and chronic rejection while maximizing patient survival and long-term graft function. However, the expected effects of IMT must be balanced against the major adverse effects of these drugs and their toxicity. The purpose of this review is to summarize world experience on current immunosuppressive strategies and to assess their effects on renal function.

Post-Transplantation Anemia and Risk of Death Following Lung Transplantation

BACKGROUND

Post-transplantation anemia (PTA) is frequent among solid organ transplant recipients and has been associated with increased morbidity and mortality. However, the prevalence and impact of PTA in lung transplant recipients is still not elucidated.

METHODS

We performed a retrospective cohort study of adult Danish lung transplant recipients between January 2010 and December 2019. The prevalence and severity of PTA were determined during the first three years post-transplantation. Associations between PTA and selected risk factors were established using uni- and multivariate logistic regression models.

RESULTS

A total of 278 patients were included. At one and three years post-lung transplantation the prevalence of PTA was 75% and 52%, respectively. Male sex was associated with increased odds of PTA at all time points (aOR ranging from 2.3, 95% CI 1.1-4.6, P = 0.02 to 5.9, 95% CI 2.6-14, P < .001). Cystic fibrosis was also associated with anemia at one-year post-transplantation (aOR 4.3, 95% CI 1.2-17, P = 0.03). We found no strong associations between PTA and renal function or viral infections. Excess mortality in recipients with moderate or severe anemia compared to patients with mild or no anemia was borderline statistically significant at one-year post-lung transplantation (aHR 2.0, 95% CI 0.9-4.4, P = 0.07).

DISCUSSION

Post-transplantation anemia is very common in Danish lung transplant recipients. Male sex and cystic fibrosis are independent risk factors for development of anemia. Further investigation on PTA, the underlying mechanisms, and its clinical impact is needed.

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.

Review: immunosuppression for the lung transplant patient

Lung transplantation (LTx) has evolved significantly since its inception and the improvement in LTx outcomes over the last three decades has predominantly been driven by advances in immunosuppression management. Despite the lack of new classes of immunosuppression medications, immunosuppressive strategies have evolved significantly from a universal method to a more targeted approach, reflecting a greater understanding of the need for individualized therapy and careful consideration of all factors that are influenced by immunosuppression choice. This has become increasingly important as the demographics of lung transplant recipients have changed over time, with older and more medically complex candidates being accepted and undergoing LTx. Furthermore, improved survival post lung transplant has translated into more immunosuppression related comorbidities long-term, predominantly chronic kidney disease (CKD) and malignancy, which has required further nuanced management approaches. This review provides an update on current traditional lung transplant immunosuppression strategies, with modifications based on pre-existing recipient factors and comorbidities, peri-operative challenges and long term complications, balanced against the perpetual challenge of chronic lung allograft dysfunction (CLAD). As we continue to explore and understand the complexity of LTx immunology and the interplay of different factors, immunosuppression strategies will require ongoing critical evaluation and personalization in order to continue to improve lung transplant outcomes.

Acute Pulmonary Edema Due to Arteriovenous Shunt Placement after Lung Transplant

Lung transplant recipients are often complicated by immunosuppressant-induced nephropathy, which may require renal replacement therapy. We report a case of unilateral lung edema and pulmonary hypertension due to arteriovenous fistula placement in a patient with unilateral chronic lung allograft dysfunction after bilateral living-donor lobar lung transplantation. Lung transplant recipients with limited residual vascular beds, such as lobar graft or severe deviation in lung perfusion, are vulnerable to the acute increase in blood flow due to arteriovenous fistula placement and can easily develop pulmonary edema regardless of the left ventricular function. Hence, careful volume control is required.

Long-term outcomes of living-donor lobar lung transplantation

OBJECTIVE

Although living-donor lobar lung transplantation (LDLLT) enables an intermediate survival similar to cadaveric lung transplantation, the long-term outcome remains unknown. We examined the long-term outcomes of 30 patients who received LDLLT more than 16 years previously.

METHODS

We retrospectively reviewed the clinical data of 30 patients who underwent LDLLT (bilateral LDLLT, 29 patients; single LDLLT, 1 pediatric patient) between October 1998 and April 2004.

RESULTS

LDLLT was performed for 25 female and 5 male patients ranging in age from 8 to 55 years. The diagnoses included pulmonary hypertension (n = 11), pulmonary fibrosis (n = 7), bronchiolitis obliterans (n = 5), and others (n = 7). At a median follow-up of 205 months, 22 patients were alive and 8 were dead. The causes of death were infection (n = 3), malignancy (n = 2), acute rejection (n = 2), and chronic lung allograft dysfunction (CLAD; n = 1). Unilateral CLAD occurred in 17 patients (56.7%), but only 1 of these patients subsequently developed bilateral CLAD. Two patients underwent bilateral cadaveric lung retransplantations. The 5-, 10-, and 15-year CLAD-free survival rates were 80.0%, 62.8%, and 44.3%, respectively. Malignancy occurred in 7 patients. Two of 5 patients with chronic kidney disease requiring hemodialysis underwent living-donor kidney transplantation. The 5-, 10-, and 15-year overall survival rates were 96.7%, 86.7%, and 73.3%, respectively.

CONCLUSIONS

Although only 2 lobes are implanted, LDLLT provides encouraging long-term outcomes. In patients with unilateral CLAD, the functioning contralateral graft might contribute to a favorable long-term outcome.

Kidney disease in children with heart or liver transplant

Over the past few decades, there has been increasing recognition of kidney disease in children with non-kidney solid organ transplantation. The risk of kidney disease in children undergoing heart or liver transplantation is higher than the general population as the underlying disease and its associated management may directly impair kidney function. Both heart and liver failures contribute to hypoperfusion and kidney ischemia before patients reach the point of transplant. The transplant surgery itself can often be complicated by acute kidney injury (AKI), which may be further exacerbated by a complicated postoperative course. In the short- and long-term post-transplant period, these children are at risk of acute illness, exposed to nephrotoxic medications, and susceptible to rare but severe infections and immunologic insults that may contribute to AKI and chronic kidney disease (CKD). In some, CKD can progress to kidney failure with replacement therapy (KFRT). CKD and KFRT are associated with increased morbidity and mortality in this patient population. Therefore, it is critical to monitor for and recognize the risk factors for kidney injury in this population and mitigate these risks. In this paper, the authors provide an overview of kidney disease pertaining to heart and liver transplantation in children with guidance on monitoring, diagnosis, prevention, and management.

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.

Factors affecting complications development and mortality after single lung transplant

Lung transplantation (LT) is a life-saving therapeutic procedure that prolongs survival in patients with end-stage lung disease. Furthermore, as a therapeutic option for high-risk candidates, single LT (SLT) can be feasible because the immediate morbidity and mortality after transplantation are lower compared to sequential single (double) LT (SSLTx). Still, the long-term overall survival is, in general, better for SSLTx. Despite the great success over the years, the early post-SLT period remains a perilous time for these patients. Patients who undergo SLT are predisposed to evolving early or late postoperative complications. This review emphasizes factors leading to post-SLT complications in the early and late periods including primary graft dysfunction and chronic lung allograft dysfunction, native lung complications, anastomosis complications, infections, cardiovascular, gastrointestinal, renal, and metabolite complications, and their association with morbidity and mortality in these patients. Furthermore, we discuss the incidence of malignancy after SLT and their correlation with immunosuppression therapy.

Acute kidney injury after lung transplantation: a narrative review

Acute kidney injury (AKI) is a commonly recognized complication after lung transplantation (LT) and is related to increased mortality and morbidity. With the improvement of survival after LT and the increasing number of lung transplant recipients, the detrimental impact of current management on renal function has become increasingly apparent. Multifarious risk factors in the perioperative setting contribute to the development of AKI, including the preoperative status and complications of the recipient, complex perioperative problems especially hemodynamic fluctuation, and exposure to nephrotoxic agents, mainly calcineurin inhibitors (CNIs) and antimicrobial drugs. Identification and minimization of the effects of these risk factors can relieve AKI severity and incidence in high-risk patients. Close monitoring of urine output and serum creatinine (sCr) levels and of specific biomarkers may promote early recognition of AKI and rapid nephrology intervention to improve outcomes. This review summarizes advances in the epidemiology, diagnostic criteria, biological markers of AKI, and further recommends appropriate treatment strategies for the long-term management of AKI related manifestations in lung transplant recipients. Future work will need to focus on developing more accurate measures of renal function and identifying patients before the occurrence of early renal damage. Combining renal protection strategies with the use of new biomarkers to develop early kidney risk identification and protection protocols is a promising idea that requires further investigation.

Identifying the association between tacrolimus exposure and toxicity in heart and lung transplant recipients: A systematic review

AIMS

Tacrolimus is the cornerstone of immunosuppression management in heart and lung transplant recipients, improving overall survival. However, tacrolimus-associated toxicities, including nephrotoxicity, neurotoxicity, new-onset diabetes mellitus after transplant (NODAT), and gastrointestinal toxicity, are known contributors to increased post-transplant morbidity outcomes and reduced graft and recipient survival rates. The aim of this systematic review was to identify correlations between pharmacokinetic measures of tacrolimus exposure in heart and lung recipients and tacrolimus toxicities.

METHODS

MEDLINE, Embase, the Cochrane Library, CENTRAL and WHO Clinical Trial Registries were searched for published studies evaluating tacrolimus toxicities and their correlation to pharmacokinetic monitoring parameters in thoracic transplant recipients. Studies were reviewed by two authors, with data extracted for evaluation. Risk of bias was assessed using the PEDro scale for randomised control trials and the Newcastle Ottawa Scale for non-randomised cohort studies.

RESULTS

Eighteen studies were eligible; a randomised control trial, 11 observational cohort studies, and 6 case series or studies. Of these, 9 studies were in heart transplant recipients alone and 5 in lung transplant recipients alone, 2 studies were in heart and lung transplant recipients and 2 were heart, lung, liver or renal transplant recipients. Studies used variable criteria to define toxicities. Tacrolimus trough concentration (C₀) was the marker of tacrolimus exposure most commonly used. Ten studies reported on nephrotoxicity. Elevated tacrolimus C₀ was associated with acute kidney injury occurrence and severity in three observational studies. Increasing C₀ was a predictor of renal impairment in 6 studies. One study found that for each 5 ng/mL per year of tacrolimus exposure, defined by consecutive AUC, eGFR declined by 1.3 mL/min/1.73m² (p < 0.001). Comparatively, 2 studies failed to find a significant association between nephrotoxicity and tacrolimus exposure. Seven studies reported on neurotoxicity, including neuro-encephalopathies, polyneuropathies and symptomatic change in neurological status. Neurotoxicity occurred both with tacrolimus C₀ within therapeutic range and with supratherapeutic C₀. No significant association was found between NODAT and tacrolimus C₀ in two studies. One study reported on gastrointestinal toxicity, with supratherapeutic C₀ and elevated peak concentration in one lung transplant recipient three days prior to symptom development.

CONCLUSION

No clearly defined relationship between tacrolimus exposure and toxicities is described in the literature. Studies with clear toxicity criteria and pharmacokinetic markers of tacrolimus exposure are required to provide valuable information that may optimise tacrolimus therapy, helping to reduce toxicities in heart and lung transplant recipients.

Real life experience with mTOR-inhibitors after lung transplantation

Mammalian target of rapamycin inhibitors (mTORi) are increasingly used after lung transplantation as part of a calcineurin inhibitor sparing regimen, aiming to preserve renal function. The aim of our study was to determine whether immunosuppressive therapy using mTORi in lung transplant recipients (LTR) is feasible in practice, or limited by intolerance and adverse events. Data were retrospectively assessed for all LTR transplanted between July 1991 and January 2020. Patients ever receiving mTORi (monotherapy or in combination with calcineurin inhibitor) as treatment of physicians' choice were included. 149/1184 (13%) of the LTR ever received mTORi. Main reasons to start were renal insufficiency (67%) and malignancy (21%). In 52% of the patients, mTORi was stopped due to side effects or drug toxicity after a median time of 159 days. Apart from death, main reasons for discontinuation were infection (19%) and edema (14%). Early discontinuation (<90 days) was mainly due to edema or gastrointestinal intolerance. As mTORi was stopped due to adverse events or drug intolerance in 52% of LTR, cautious consideration of advantages and disadvantages when starting mTORi is recommended.

The Irish experience of kidney transplantation among recipients with prior non-renal solid organ transplants: A retrospective study on short- and long-term outcomes

BACKGROUND

This study aims to evaluate allograft and patient outcomes among recipients of kidney transplants after non-renal solid organ transplants. We also aim to compare our findings with recipients of a repeat kidney transplant.

METHODS

We performed an analysis on kidney transplant recipients who underwent kidney transplantation after a non-renal solid organ transplant. Survival data were stratified into 2 groups: Group A (n = 37) consisted of recipients of a kidney transplant after prior non-renal solid organ transplant, and Group B (n = 330) consisted of recipients of a repeat kidney transplant.

RESULTS

The 1-,5-, and 10-year graft survival (death-censored) for recipients of a kidney transplant post-non-renal solid organ transplant (Group A) were 97.3%, 91.5%, and 86.9%, compared with 97.9%, 90.2%, and 83.4% for recipients of a repeat kidney transplant (Group B) (p = .32). The 1-, 5-, and 10-year patient survival rates were 97.3%, 82.7%, and 79.1% in Group A compared to 97.9%, 90.2%, and 83.4% in Group B. Unadjusted overall patient survival was significantly lower for Group A (p = .017).

CONCLUSION

Kidney transplant recipients who have undergone a previous non-renal solid organ transplant have similar allograft survival outcomes, but higher long-term mortality rates compared to repeat kidney transplant recipients.

Intravascular ultrasound-guided selection for early noninvasive cardiac allograft vasculopathy screening in heart transplant recipients

BACKGROUND

Noninvasive screening for cardiac allograft vasculopathy (CAV) instead of invasive coronary angiography (ICA) within the first 3 to 5 years after heart transplantation (HTx) is controversial. We evaluated a strategy of intravascular ultrasound (IVUS)-guided conversion to early noninvasive screening post-HTx.

METHODS

A single-center study of 103 consecutive HTx recipients from 2008 to 2018 undergoing ICA at 1 year post-HTx. Of 88 patients with normal 1-year ICA, sixty-six patients underwent IVUS examination for risk stratification by maximal intimal thickness (MIT) into (i) low-risk group (MIT < 0.5 mm) (n = 41, 62%) followed noninvasively versus (ii) high-risk group (MIT ≥ 0.5 mm) (n = 25, 38%) followed with yearly ICA. Both groups underwent ICA at year 5 post-HTx. We evaluated a combined endpoint of angiographic CAV and death at 5-year follow-up post-HTx.

RESULTS

Median (IQR) age was 51 (33-60) years, and 62% were male. Follow-up was 1443 (1125-1456) days. Survival free from angiographic CAV (Kaplan-Meier) differed significantly between groups (log-rank p < .0001). A subgroup of 27 patients completed ICA at year 5, and the proportion of angiographic CAV was significantly lower in low-risk patients (p < .0001).

CONCLUSION

IVUS-guided selection for early noninvasive CAV screening appears to be safe and holds promise as a novel strategy for early risk stratification and CAV surveillance post-HTx.

Combined Single Lung and Liver Transplantation in a Cystic Fibrosis Patient With Previous Contralateral Pneumonectomy: A Case Report

Combined lung-liver transplantation is a rare life-saving procedure to treat concomitant end-stage lung and liver failure. In this report, we describe the first published case of single lung and liver transplantation in a cystic fibrosis patient who had previously undergone a pneumonectomy for the treatment of an infected and destroyed right lung. We detail the lung first, sequential transplant procedure and surgical difficulties due to mediastinal shift. Emergent intraoperative renal replacement therapy was carried out before liver transplantation to overcome pulmonary edema in the transplanted lung. After fluid balance equilibration, liver transplantation was performed in good conditions. The patient is currently alive with no signs of rejection 8 years after the procedure.

Acute kidney injury and chronic kidney disease after non-kidney solid organ transplantation

BACKGROUND

SOT is the treatment of choice for end-stage organ disease. Improved long-term survival after NKSOT has uncovered chronic morbidity including CKD. AKI is common after NKSOT and may be associated with long-term CKD.

METHODS

We performed a retrospective cohort study looking at AKI and CKD after pediatric heart (n = 109) or liver (n = 112) transplant. AKI was defined using KDIGO creatinine-based criteria. pAKI was AKI ≤ 7 days post-transplant; CKD_3-5 was eGFR < 60 mL/min/1.73 m² by modified Schwartz formula for > 3 months. We looked at the incidence of CKD_3-5 and the effect of perioperative pAKI on the slope of eGFR post-transplant.

RESULTS

pAKI was seen in 63% (n = 69) after heart and 38% (n = 43) after liver transplant. pAKI was associated with longer ICU and hospital stays. Cumulative incidence (95% CI) of CKD_3-5 at 60 months post-heart transplant was 40.9% (27.9%-57.1%) in patients with AKI vs 35.8% (17.1%-64.8%) in those without (P = NS). Post-liver transplant, the cumulative incidence of CKD_3-5 at 60 months was 0% in those without pAKI vs 10% (3.2%-29.3%) in those with (P = .01). Patients with pAKI had lower eGFR at last follow-up.

CONCLUSION

pAKI and CKD are common after NKSOT. Incidence of CKD is higher in those with pAKI. AKI episodes are associated with a drop in eGFR during follow-up. Identifying patients who have had AKI is an important first step in identifying those at risk of repeated AKI episodes. These patients would benefit from closer monitoring for CKD, lower nephrotoxic drug use, and follow-up with nephrology.

Early Tacrolimus Concentrations After Lung Transplant Are Predicted by Combined Clinical and Genetic Factors and Associated With Acute Kidney Injury

Tacrolimus exhibits unpredictable pharmacokinetics (PKs) after lung transplant, partly explained by cytochrome P450 (CYP)-enzyme polymorphisms. However, whether exposure variability during the immediate postoperative period affects outcomes is unknown, and pharmacogenetic dosing may be limited by residual PK variability. We estimated adjusted associations between early postoperative tacrolimus concentrations and acute kidney injury (AKI) and acute cellular rejection (ACR), and identified clinical and pharmacogenetic factors that explain postoperative tacrolimus concentration variability in 484 lung transplant patients. Increasing tacrolimus concentration was associated with higher AKI risk (hazard ratio (HR) 1.54; 95% confidence interval (CI) 1.20-1.96 per 5-mg/dL); and increasing AKI severity (odds ratio 1.29; 95% CI 1.04-1.60 per 5-mg/dL), but not ACR (HR 1.02; 95% CI 0.73-1.42). A model with clinical and pharmacogenetic factors explained 42% of concentration variance compared with 19% for pharmacogenetic factors only. Early tacrolimus exposure was independently associated with AKI after lung transplantation, but not ACR. Clinical factors accounted for substantial residual tacrolimus concentration variability not explained by CYP-enzyme polymorphisms.

Acute Kidney Injury after Lung Transplantation: A Systematic Review and Meta-Analysis

Background: Lung transplantation has been increasingly performed worldwide and is considered an effective therapy for patients with various causes of end-stage lung diseases. We performed a systematic review to assess the incidence and impact of acute kidney injury (AKI) and severe AKI requiring renal replacement therapy (RRT) in patients after lung transplantation. Methods: A literature search was conducted utilizing Ovid MEDLINE, EMBASE, and Cochrane Database from inception through June 2019. We included studies that evaluated the incidence of AKI, severe AKI requiring RRT, and mortality risk of AKI among patients after lung transplantation. Pooled incidence and odds ratios (ORs) with 95% confidence interval (CI) were obtained using random-effects meta-analysis. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42019134095). Results: A total of 26 cohort studies with a total of 40,592 patients after lung transplantation were enrolled. Overall, the pooled estimated incidence rates of AKI (by standard AKI definitions) and severe AKI requiring RRT following lung transplantation were 52.5% (95% CI: 45.8–59.1%) and 9.3% (95% CI: 7.6–11.4%). Meta-regression analysis demonstrated that the year of study did not significantly affect the incidence of AKI (p = 0.22) and severe AKI requiring RRT (p = 0.68). The pooled ORs of in-hospital mortality in patients after lung transplantation with AKI and severe AKI requiring RRT were 2.75 (95% CI, 1.18–6.41) and 10.89 (95% CI, 5.03–23.58). At five years, the pooled ORs of mortality among patients after lung transplantation with AKI and severe AKI requiring RRT were 1.47 (95% CI, 1.11–1.94) and 4.79 (95% CI, 3.58–6.40), respectively. Conclusion: The overall estimated incidence rates of AKI and severe AKI requiring RRT in patients after lung transplantation are 52.5% and 9.3%, respectively. Despite advances in therapy, the incidence of AKI in patients after lung transplantation does not seem to have decreased. In addition, AKI after lung transplantation is significantly associated with reduced short-term and long-term survival.

Kidney Transplantation in Patients With Chronic Kidney Disease After a Previous Lung Transplantation

BACKGROUND

The development of chronic kidney disease is a common complication after a lung transplantation, especially since the introduction of immunosuppressive treatments based on calcineurin inhibitors. Many of these patients reach end-stage renal disease and even need renal replacement therapy. Among the different options of renal replacement therapy, we consider kidney transplantation as a feasible option for these patients.

METHODS

A single center, observational retrospective study including 8 lung transplanted patients who have received a kidney transplant in the period between 2013 and 2017 with at least 1 year of follow-up was used.

RESULTS

Seven patients maintained an adequate function of the graft 1 year after kidney transplantation, and 1 patient died because of a pulmonary condition in spite of a previous kidney transplant. Two patients presented delayed graft function in the first days after surgery.

CONCLUSIONS

The kidney transplantation is a technique of renal replacement therapy that should be considered in patients with previous lung transplantation. Experienced centers in double sequential lung and kidney transplantation should be established to assess and treat these types of patients.

Long-Term Outcomes of Adult Lung Transplantation Recipients: A Single-Center Experience in South Korea

Background

Recently, the number of lung transplants in South Korea has increased. However, the long-term outcome data is limited. In this study, we aimed to investigate the long-term outcomes of adult lung transplantation recipients.

Methods

Among the patients that underwent lung transplantation at a tertiary referral center in South Korea between 2008 and 2017, adults patient who underwent deceased-donor lung transplantation with available follow-up data were enrolled. Their medical records were retrospectively reviewed.

Results

Through eligibility screening, we identified 60 adult patients that underwent lung (n=51) or heart-lung transplantation (n=9) during the observation period. Idiopathic pulmonary fibrosis (46.7%, 28/60) was the most frequent cause of lung transplantation. For all the 60 patients, the median follow-up duration for post-transplantation was 2.6 years (range, 0.01–7.6). During the post-transplantation follow-up period, 19 patients (31.7%) died at a median duration of 194 days. The survival rates were 75.5%, 67.6%, and 61.8% at 1 year, 3 years, and 5 years, respectively. Out of the 60 patients, 8 (13.3%) were diagnosed with chronic lung allograft dysfunction (CLAD), after a mean duration of 3.3±2.8 years post-transplantation. The CLAD development rate was 0%, 17.7%, and 25.8% at 1 year, 3 years, and 5 years, respectively. The most common newly developed post-transplantation comorbidity was the chronic kidney disease (CKD; 54.0%), followed by diabetes mellitus (25.9%).

Conclusion

Among the adult lung transplantation recipients at a South Korea tertiary referral center, the long-term survival rates were favorable. The proportion of patients who developed CLAD was not substantial. CKD was the most common post-transplantation comorbidity.

Complications of Solid Organ Transplantation: Cardiovascular, Neurologic, Renal, and Gastrointestinal

Despite improvements in overall graft function and patient survival rates after solid organ transplantation, complications can lead to significant morbidity and mortality. Cardiovascular complications include heart failure, arrhythmias leading to sudden death, hypertension, left ventricular hypertrophy, and allograft vasculopathy in heart transplantation. Neurologic complications include stroke, posterior reversible encephalopathy syndrome, infections, neuromuscular disease, seizure disorders, and neoplastic disease. Acute kidney injury occurs from immunosuppression with calcineurin inhibitors or as a result of graft failure after kidney transplantation. Gastrointestinal complications include infections, malignancy, mucosal ulceration, perforation, biliary tract disease, pancreatitis, and diverticular disease. Immunosuppression can predispose to infections and malignancy.

Frailty and clinical benefits with lung transplantation

BACKGROUND

The Fried frailty phenotype is associated with morbidity and mortality in lung transplant (LTx) candidates, but its clinical application and association with post-transplant outcomes are not well defined. We assessed 2 alternate frailty indices in LTx candidates and evaluated associations of frailty with early post-transplant outcomes and 1-year mortality.

METHODS

Frailty was prospectively evaluated in 50 LTx candidates using the Fried and 2 alternate phenotypic indices, one using variables readily available to clinicians and one using variables from an existing data set. Agreement between indices and associations with related measures were assessed to establish validity. The data set index was then applied retrospectively to 221 LTx patients. Post-transplant outcomes were compared between frail and non-frail patients using t-tests and multivariable regression analysis.

RESULTS

Frailty prevalence among the 3 indices was 26% to 30%, and the κ agreement was 0.38 to 0.41. All indices had moderate correlations with London Chest Activity of Daily Living (r = 0.48-0.62) and Short-Physical Performance Battery (r = -0.43 to -0.52). In the retrospective cohort, frail LTx candidates had a worse St. George's Respiratory Questionnaire total score (73 ± 12vs 62 ± 12, p < 0.001). Frail candidates had a larger improvement with transplant in the St. George's Respiratory Questionnaire (-52 ± 19vs -43 ± 18, p = 0.002) and 6-minute walk distance (191 ± 119vs 129 ± 94m, p = 0.001). Frailty was not associated with hospital length of stay or 1-year mortality.

CONCLUSIONS

There was good construct validity and acceptable agreement among the frailty indices. Despite significant disability pre-transplant, frail LTx candidates derived significant benefit with transplantation.

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.

Perioperative Management of Cardiac Transplant Recipients Undergoing Noncardiac Surgery: Unique Challenges Created by Advancements in Care

Advancements in postcardiac transplant care have resulted in significant reductions in morbidity and increased life expectancy for cardiac transplant recipients. Consequently, many cardiac transplant recipients are living long enough to require subsequent noncardiac surgery. The perioperative care of heart transplant recipients presents a unique challenge as many of the common preoperative risk assessments do not apply to a transplanted heart, immunosuppressive medications have side effects and potential for drug-drug interactions, and the denervated heart results in an altered autonomic physiology and response to medications. Further adding to the challenge is that many of these noncardiac surgeries need to be performed urgently at nontransplant centers that may not be familiar with the care of these patients. This review aims to summarize the current data regarding preoperative assessment, perioperative immunosuppression management, intraoperative and anesthetic considerations, and outcomes of cardiac transplant recipients undergoing noncardiac surgery.

Effect of Calcineurin Inhibitor-Free, Everolimus-Based Immunosuppressive Regimen on Albuminuria and Glomerular Filtration Rate After Heart Transplantation

BACKGROUND

Albuminuria in maintenance heart transplantation (HTx) is associated with poor renal response when switching to a calcineurin inhibitor (CNI)-lowered or CNI-free immunosuppressive regimen using everolimus (EVR), but the significance of albuminuria associated with EVR treatment after early CNI withdrawal in de novo HTx is unknown.

METHODS

We tested if measured glomerular filtration rate (mGFR, by chrome-ethylenediaminetetraacetic acid clearance) was associated with urine albumin/creatinine ratio (UACR) post-HTx in a subgroup of patients included in the Scandinavian Heart Transplant Everolimus De Novo Study With Early Calcineurin Inhibitor Avoidance trial, where de novo HTx patients (n = 115) were randomized to EVR with complete CNI elimination 7 to 11 weeks post-HTx or standard CNI immunosuppression.

RESULTS

In 66 patients, UACR measures were available at 1 year. In 7 patients in the EVR group, a CNI was reintroduced within 12 months. Median mGFR was significantly higher in the EVR group both 1 and 3 years post-HTx (P = 0.0004 and P = 0.03, respectively). Median UACR at 1 year was significantly higher in the EVR group (P = 0.002). There was no correlation between log(UACR) at 1 year and mGFR at 1 or 3 years (r = -0.01, P = 0.9 and r = 0.15, P = 0.26, respectively) and in the EVR group between log(UACR) at 1 year and change in mGFR (Δ1-3 years) (r = 0.27, P = 0.14). Excluding patients in the EVR group in whom a CNI was reintroduced did not significantly change the results.

CONCLUSIONS

The effects of EVR with early CNI withdrawal after HTx on albuminuria and renal function seem dissociated; hence, the clinical significance of albuminuria in this setting is uncertain and should not necessarily rule out EVR-based immunosuppression.

Janus kinase inhibition for immunosuppression in solid organ transplantation: Is there a role in complex immunologic challenges?

Inhibition of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway for immunosuppression in solid organ transplantation is appealing due to its specificity for immune cell function, particularly for JAK3. This is due to its unique association with only the common gamma chain (γ_c). The γ_c is an appealing immunosuppression target in transplantation because of the critically important lymphokines that act at it, including IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Tofacitinib was initially purported to selectively inhibit solely JAK3, but subsequent analyses have also demonstrated its activity at the other members of the JAK family. Clinical outcomes have validated tofacitinib's pan-JAK activity in kidney transplantation after demonstrating an increased risk of infection and malignancy as compared to CNI-based regimens. After these trials, tofacitinib investigation for use in transplantation has effectively ceased. However, a post-hoc analysis has shed new light on the monitoring of tofacitinib exposure in order to predict infection and oncologic events. With new methods to monitor tofacitinib exposure, clinicians may be able to effectively reduce toxicities while providing a high level of immunosuppression. The purpose of this review to identify when, and for whom, JAK inhibitors may provide benefit in solid organ transplantation.

Everolimus Versus Mycophenolate Mofetil De Novo After Lung Transplantation: A Prospective, Randomized, Open-Label Trial

The role of mammalian target of rapamycin (mTOR) inhibitors in de novo immunosuppression after lung transplantation is not well defined. We compared Everolimus versus mycophenolate mofetil in an investigator-initiated single-center trial in Hannover, Germany. A total of 190 patients were randomly assigned 1:1 on day 28 posttransplantation to mycophenolate mofetil (MMF) or Everolimus combined with cyclosporine A (CsA) and steroids. Patients were followed up for 2 years. The primary endpoint was freedom from bronchiolitis obliterans syndrome (BOS). The secondary endpoints were incidence of acute rejections, infections, treatment failure and kidney function. BOS-free survival in intention-to-treat (ITT) analysis was similar in both groups (p = 0.174). The study protocol was completed by 51% of enrolled patients. The per-protocol analysis shows incidence of bronchiolitis obliterans syndrome (BOS): 1/43 in the Everolimus group and 8/54 in the MMF group (p = 0.041). Less biopsy-proven acute rejection (AR) (p = 0.005), cytomegalovirus (CMV) antigenemia (p = 0.005) and lower respiratory tract infection (p = 0.003) and no leucopenia were seen in the Everolimus group. The glomerular filtration rate (GFR) decreased in both groups about 50% within 6 months. Due to a high withdrawal rate, the study was underpowered to prove a difference in BOS-free survival. The dropout rate was more pronounced in the Everolimus group. Secondary endpoints indicate potential advantages of Everolimus-based protocols but also a potentially higher rate of drug-related serious adverse events.

Stimulation of Dopamine D3 Receptor Attenuates Renal Ischemia-Reperfusion Injury via Increased Linkage With Gα12

BACKGROUND

Renal ischemia-reperfusion (I/R) injury causes renal tubular necrosis, apoptosis, and inflammation leading to acute renal dysfunction. Recent studies have revealed that deletion of Gα12 mitigates the renal damage due to I/R injury. Our previous study showed that activation of dopamine D3 receptor (D3R) increased its linkage with Gα12, and hampered Gα12-mediated stimulation of renal sodium transport. In the present study, we used an in-vivo rat model and an in vitro study of the renal epithelial cell line (NRK52E) to investigate whether or not an increased linkage between D3R and Gα12 contributes to the protective effect of D3R on renal I/R injury.

METHODS

For in vivo studies, I/R injury was induced in a rat renal unilateral clamping model. For in vitro studies, hypoxia/reoxygenation and cold storage/rewarming injuries were performed in NRK52E cells. PD128907, a D3R agonist, or vehicle, was administered 15 minutes before clamping (or hypoxia) in both the in vivo or in vitro studies.

RESULTS

In the rat renal unilateral clamping model, pretreatment with PD128907 (0.2 mg/kg, intravenous) protected against renal I/R injury and increased survival rate during a long-term follow-up after 7 days. A decrease in the generation of reactive oxygen species, apoptosis, and inflammation may be involved in the D3R-mediated protection because pretreatment with PD128907 increased renal glutathione and superoxide dismutase levels and decreased malondialdehyde levels in the I/R group. The increase in cytokines (TNF-α, IL-1β, and IL-10) and myeloperoxidase in I/R injured kidney was also prevented with a simultaneous decrease in the apoptosis of the epithelial cells and expression of apoptosis biomarkers in kidney harvested 1 day after I/R injury. The increase in the coimmunoprecipitation between D3R and Gα12 with D3R stimulation paralleled the observed renal protection from I/R injury. Moreover, in vitro studies showed that transient overexpression of Gα12 in the NRK52E cells attenuated the protective effect of PD128907 on hypoxia/reoxygenation injury. The protective effect of PD128907 might be of significance to renal transplantation because cold storage/rewarming induced injury increased lactate dehydrogenase release and decreased cell viability in NRK52E cells. Conversely, in the presence of PD128907, the increased lactate dehydrogenase release and decreased cell viability were reversed.

CONCLUSIONS

These results suggest that activation of D3R, by decreasing Gα12-induced renal damage, may exert a protective effect from I/R injury.

Pharmacokinetics and Toxicity of Tacrolimus Early After Heart and Lung Transplantation

Annually, about 8000 heart and lung transplantations are successfully performed worldwide. However, morbidity and mortality still pose a major concern. Renal failure in heart and lung transplant recipients is an essential adverse cause of morbidity and mortality, often originating in the early postoperative phase. At this time of clinical instability, the kidneys are exposed to numerous nephrotoxic stimuli. Among these, tacrolimus toxicity plays an important role, and its pharmacokinetics may be significantly altered in this critical phase by fluctuating drug absorption, changed protein metabolism, anemia and (multi-) organ failure. Limited understanding of tacrolimus pharmacokinetics in these circumstances is hampering daily practice. Tacrolimus dose adjustments are generally based on whole blood trough levels, which widely vary early after transplantation. Moreover, whole blood trough levels are difficult to predict and are poorly related to the area under the concentration-time curve. Even within the therapeutic range, toxicity may occur. These shortcomings of tacrolimus monitoring may not hold for the unbound tacrolimus plasma concentrations, which may better reflect tacrolimus toxicity. This review focuses on posttransplant tacrolimus pharmacokinetics, discusses relevant factors influencing the unbound tacrolimus concentrations and tacrolimus (nephro-) toxicity in heart and lung transplantation patients.

Usefulness of Rabbit Anti-thymocyte Globulin in Patients With Giant Cell Myocarditis

Giant cell myocarditis (GCM) is an aggressive inflammatory myocardial disease. Immunosuppression is an effective treatment for some cases. However, the duration of action of agents such as muromonab CD3 is short and others such as the calcineurin inhibitors may lead to renal failure. Here we describe the outcome of a novel approach to treatment using rabbit anti-thymocyte globulin (RATG). A retrospective analysis of 6 patients treated with RATG for GCM was performed. Diagnosis was confirmed by endomyocardial biopsy, and RATG was administered with a high dose of corticosteroids. None of the patients had cytokine release syndrome or leukopenia, and 5 had thrombocytopenia (2 of them severe). Only 1 had a serious bleeding event that occurred after implantation of mechanical circulatory support. None developed impaired renal function after the treatment. Five were successfully discharged home with an increase in global left ventricular ejection fraction of 29%. Four are currently alive without recurrent disease, 1 of them after heart transplantation, with a mean follow-up of 970 days (423 to 1,875 days), left ventricular ejection fraction of 53%, and all in current New York Heart Association Classification class ≤II. Only 1 case had GCM recurrence. There were 2 deaths: one because of intracranial bleeding after mechanical circulatory support implantation and the other caused by primary graft dysfunction. In conclusion, patients with GCM can be successfully immunosuppressed with RATG and corticosteroids, thereby avoiding renal impairment. Early thrombocytopenia is the main adverse event. Larger cohorts of patients are necessary to compare the different immunosuppressant strategies available for GCM in a randomized fashion.

Long-term successful outcomes from kidney transplantation after lung and heart-lung transplantation

BACKGROUND

Renal dysfunction is common after lung and heart-lung transplantation (Tx), and it limits the recipient's survival and quality of life. This study analyzed the outcomes of simultaneous and late kidney Tx following lung and heart-lung Tx.

METHODS

From a single-center retrospective chart review of 1031 lung and heart-lung Tx recipients, we identified 13 simultaneous or late kidney Tx cases in 12 patients.

RESULTS

Three patients underwent simultaneous deceased donor lung and kidney Tx. Eight patients underwent lung and heart-lung Tx, followed by nine living donor kidney Tx (including one ABO-incompatible Tx). One additional patient underwent a late deceased donor kidney Tx following heart-lung Tx. The median time from lung and heart-lung Tx to later kidney Tx was 127 (interquartile range [IQR], 23 to 263) months. Three patients died, 1 of sepsis, 1 of multiple organ failure, and 1 of transplant coronary disease. At a median follow-up of 33 (IQR, 10 to 51) months, 9 patients are alive and well. Eight patients required dialysis before kidney Tx for a median time of 14 months (IQR, 5 to 49). Kidney graft loss occurred in 1 patient at 51 months. After kidney Tx, dialysis was necessary in association with acute allograft dysfunction in 2 patients. No acute kidney rejection has been detected in any patient. Treatable acute lung rejection was seen in 1 patient. Well-preserved pulmonary function was noted in recipients of late kidney Tx.

CONCLUSIONS

Simultaneous kidney Tx and late deceased donor kidney Tx have challenges in the setting of lung Tx. By contrast, late living related kidney Tx after lung Tx is associated with excellent long-term survival and acceptable kidney and lung allograft function.

Biomarkers of calcineurin inhibitor nephrotoxicity in transplantation

Over 35 years of use has demonstrated the revolutionary therapeutic benefits of calcineurin inhibitors (CNI) in not only preventing transplant rejection, but also the renal and nonrenal toxicity of CNI. Acute reversible and insidious irreversible forms of CNI nephrotoxicity have been identified, with ischemia from an imbalance between vasoconstrictors and vasodilators playing an important role. The ongoing search to define toxicity pathways has been enriched by ‘Omics’ studies. Changes in proteins including those involved in activation of pro-inflammatory responses, oxidative stress, ER stress and the unfolded protein response have been identified, and these may serve as biomarkers of toxicity. However, the current standard of CNI toxicity, histology, lacks specificity, which creates challenges for biomarker validation. This review focuses on progress in nephrotoxic pathway identification of CNI and biomarker validation.

A risk score to predict acute renal failure in adult patients after lung transplantation

BACKGROUND

Despite the significant morbidity associated with renal failure after lung transplantation (LTx), no predictive models currently exist. Accordingly, the purpose of this study was to develop a preoperative risk score based on recipient-, donor-, and transplant-specific characteristics to predict postoperative acute renal failure in candidates for transplantation.

METHODS

The United Network of Organ Sharing (UNOS) database was queried for adult patients (≥ 18 years of age) undergoing LTx between 2005 and 2012. The population was randomly divided into derivation (80%) and validation (20%) cohorts. The primary outcome of interest was new-onset renal failure. Variables predictive of acute renal failure (exploratory p value < 0.2) within the derivation cohort were incorporated into a multivariable logistic regression model. Odds ratios were used to assign values to the independent predictors of postoperative renal failure to construct the risk stratification score (RSS).

RESULTS

During the study period, 10,963 patients underwent lung transplantation, and the incidence of renal failure was 5.5% (598 patients). Baseline recipient-, donor-, and transplant-related factors were similar between the cohorts. Eighteen covariates were included in the multivariable model, and 10 were assigned values based on their relative odds ratios (ORs). Scores were stratified into 3 groups, with an observed rate of acute renal failure of 3.1%, 5.3%, and 15.6% in the low-, moderate-, and high-risk groups, respectively. The incidence of renal failure was found to be significantly increased in the highest risk group (p < 0.001). Furthermore, the risk model's predicted rates of renal failure highly correlated with actual rates observed in the population (r = 0.86).

CONCLUSIONS

We introduce a novel and simple RSS that is highly predictive of renal failure after LTx.

Thymoglobulin induction in heart transplantation: patient selection and implications for maintenance immunosuppression

Clinical data relating to rabbit antithymocyte globulin (rATG) induction in heart transplantation are far less extensive than for other immunosuppressants, or indeed for rATG in other indications. This was highlighted by the low grade of evidence and the lack of detailed recommendations for prescribing rATG in the International Society for Heart and Lung Transplantation (ISHLT) guidelines. The heart transplant population includes an increasing frequency of patients on mechanical circulatory support (MCS), often with ongoing infection and/or presensitization, who are at high immunological risk but also vulnerable to infectious complications. The number of patients with renal impairment is also growing due to lengthening waiting times, intensifying the need for strategies that minimize calcineurin inhibitor (CNI) toxicity. Additionally, the importance of donor-specific antibodies (DSA) in predicting graft failure is influencing immunosuppressive regimens. In light of these developments, and in view of the lack of evidence-based prescribing criteria, experts from Germany, Austria, and Switzerland convened to identify indications for rATG induction in heart transplantation and to develop an algorithm for its use based on patient characteristics.

Everolimus initiation and early calcineurin inhibitor withdrawal in heart transplant recipients: a randomized trial

In a randomized, open-label trial, everolimus was compared to cyclosporine in 115 de novo heart transplant recipients. Patients were assigned within 5 days posttransplant to low-exposure everolimus (3–6 ng/mL) with reduced-exposure cyclosporine (n = 56), or standard-exposure cyclosporine (n = 59), with both mycophenolate mofetil and corticosteroids. In the everolimus group, cyclosporine was withdrawn after 7–11 weeks and everolimus exposure increased (6–10 ng/mL). The primary efficacy end point, measured GFR at 12 months posttransplant, was significantly higher with everolimus versus cyclosporine (mean ± SD: 79.8 ± 17.7 mL/min/1.73 m2 vs. 61.5 ± 19.6 mL/min/1.73 m2; p < 0.001). Coronary intravascular ultrasound showed that the mean increase in maximal intimal thickness was smaller (0.03 mm [95% CI 0.01, 0.05 mm] vs. 0.08 mm [95% CI 0.05, 0.12 mm], p = 0.03), and the incidence of cardiac allograft vasculopathy (CAV) was lower (50.0% vs. 64.6%, p = 0.003), with everolimus versus cyclosporine at month 12. Biopsy-proven acute rejection after weeks 7–11 was more frequent with everolimus (p = 0.03). Left ventricular function was not inferior with everolimus versus cyclosporine. Cytomegalovirus infection was less common with everolimus (5.4% vs. 30.5%, p < 0.001); the incidence of bacterial infection was similar. In conclusion, everolimus-based immunosuppression with early elimination of cyclosporine markedly improved renal function after heart transplantation. Since postoperative safety was not jeopardized and development of CAV was attenuated, this strategy may benefit long-term outcome.

The allo- and viral-specific immunosuppressive effect of belatacept, but not tacrolimus, attenuates with progressive T cell maturation

Tacrolimus impairs allo- and viral-specific T cell responses. Belatacept, a costimulation-based alternative to tacrolimus, has emerged with a paradoxical picture of less complete control of alloimmunity with concomitant impaired viral immunity limited to viral-naïve patients. To reconcile these signatures, bulk population and purified memory and naïve lymphocytes from cytomegalovirus (CMV)-seropositive (n=10) and CMV-seronegative (n=10) volunteers were studied using flow cytometry, interrogating proliferation (carboxyfluorescein succinimidyl ester dilution) and function (intracellular cytokine staining) in response to alloantigens or CMV-pp-65 peptides. As anticipated, T cells from CMV-experienced, but not naïve, individuals responded to pp-65 with a small percentage of their repertoire (<2.5%) consisting predominantly of mature, polyfunctional (expressing interferon gamma, tumor necrosis factor alpha and IL-2) T effector memory cells. Both CMV naïve and experienced individuals responded similarly to alloantigen with a substantially larger percentage of the repertoire (up to 48.2%) containing proportionately fewer polyfunctional cells. Tacrolimus completely inhibited responses of CMV- and allo-specific T cells regardless of their maturation. However, belatacept's effects were decreasingly evident in increasingly matured cells, with minimal effect on viral-specific triple cytokine producers and CD28-negative allo-specific cells. These data indicate that belatacept's immunosuppressive effect, unlike tacrolimus's, wanes on progressively developed effector responses, and may explain the observed clinical effects of belatacept.