Chronic kidney disease in long-term survivors of myeloablative allogeneic haematopoietic cell transplantation: prevalence and risk factors

Predictors and significance of kidney dysfunction in patients with chronic graft-versus-host disease

Kidney complications have been studied in allogeneic hematopoietic stem cell transplant patients but not specifically among chronic graft-versus-host disease (cGVHD) patients. Participants (n = 365) enrolled in the cross-sectional cGVHD natural history study (NCT00092235) were assessed for kidney dysfunction and overall survival. Kidney dysfunction was analyzed for associations in univariate and multivariable analyses. Kidney dysfunction (eGFR < 60) was found in 64 patients, and 29 patients had moderate-severe kidney dysfunction (eGFR < 45). Patients with kidney dysfunction were more likely treated with cyclosporine at evaluation or to have received it for GVHD prophylaxis, or prior treatment of GVHD. Patients with kidney dysfunction were less severely affected by cGVHD of skin, mouth, and joints/fascia. In multivariable modeling, history of cyclosporine use (OR = 2.19, 95% CI 1.13-4.25), angiotensin receptor blocker use (OR = 5.57, 95% CI 1.49-20.84), proteinuria (OR = 2.39, 95% CI 1.19-4.79), lower CRP (OR = 0.95, 95% CI 0.91-0.99), lower C3 (OR = 0.98, 95% CI 0.97-0.99), and lower hemoglobin (OR = 0.70, 95% CI 0.58-0.84) were jointly associated with kidney dysfunction. Overall survival was lower in those with moderate-severe kidney dysfunction (p = 0.015), demonstrating the importance of addressing kidney dysfunction in this population. The association of kidney dysfunction with less severe cGVHD suggests an etiology unrelated to cGVHD but potentially a consequence of drug-related toxicities.

Incidence of chronic renal injury in patients undergoing autologous stem cell transplant therapy

BACKGROUND

Haemopoietic stem cell transplant (HSCT) is a well-established treatment option for many haematologic immunologic and oncologic diseases, allowing the safe administration of high-dose chemotherapy. Increased risk of acute renal injury is associated with HSCT; however, the risk of chronic kidney injury in autologous HSCT remains unclear.

AIMS

This cohort study investigates the incidence of chronic renal injury and its predisposing factors in a single-centre population of 139 patients who underwent autologous HSCT.

METHODS

Estimated glomerular filtration rate (eGFR) was measured at baseline and at 3, 6, 12 and 24 months following autologous stem cell reinfusion and used as a marker of renal dysfunction.

RESULTS

A significant reduction in mean eGFR of patients was observed from baseline (80.62 ± 2.97 mL/min) to 24 months (71.54 ± 4.14 mL/min), independent of primary diagnosis (P = 0.0019). At baseline, 12% of the cohort had stage 3 or worse chronic renal injury and this increased to 38% by 24 months. By univariate analysis, age at baseline greater than the mean of 58 years and the occurrence of acute kidney injury during the peritransplant period emerged as predictive factors for the development of chronic kidney disease at 24 months.

CONCLUSIONS

The current results indicate there is an increased incidence of chronic renal injury in patients who have undergone autologous peripheral blood haemopoietic stem cell transplantation therapy and this injury is potentiated by the autologous stem cell transplant procedure.

Kidney Biopsy Findings Among Allogenic Hematopoietic Stem Cell Transplant Recipients With Kidney Injury: A Case Series

Rationale and Objective

The incidence of kidney disease is high in patients after allogeneic hematopoietic cell transplantation (aHCT). Although rarely performed, kidney biopsy may be useful to make a precise diagnosis because several mechanisms and risk factors can be involved, and to adjust the treatment accordingly. This case series aimed to report the spectrum of biopsy findings from patients with kidney injury after aHCT.

Study Design

Single-center retrospective case series.

Setting and Participants

All individuals who underwent a native kidney biopsy, among all adult patients who received aHCT in a tertiary hospital in Montreal (Canada) from January 1, 2010, to December 31, 2020, were identified, and the clinical data were extracted from their medical records.

Results

A total of 17 patients were included. Indications for biopsy included acute kidney injury (n=6), chronic kidney disease (n=5), nephrotic syndrome (n=4), and subnephrotic proteinuria (n=2). Pathologic findings from the kidney biopsy were heterogenous: 10 patients showed evidence of thrombotic microangiopathy (TMA), 5 of acute tubular injury, and 4 of membranous nephropathy. Cases of acute interstitial nephritis, BK virus nephropathy, immune complex nephropathy, focal and segmental glomerulosclerosis, minimal change disease, and karyomegalic-like interstitial nephritis were also described.

Limitations

There was no systematic kidney biopsy performed for all patients with kidney injury after aHCT. Only a small proportion of patients with kidney damage underwent biopsy, making the results less generalizable.

Conclusions

Kidney biopsy is useful in patients with kidney disease after aHCT to make a precise diagnosis and tailor therapy accordingly. This series is one of the few published studies describing pathologic findings of biopsies performed after aHCT in the context of acute kidney injury and chronic kidney disease. TMA was widely present on biopsy even when there was no clinical suspicion of such a diagnosis, suggesting that the current clinical criteria for a diagnosis of TMA are not sensitive enough for kidney-limited TMA.

Review of acute kidney injury and progression to chronic kidney disease in pediatric patients undergoing hematopoietic cell transplant

While acute kidney injury (AKI) after hematopoietic cell transplant (HCT) has been well-described in pediatric patients, literature regarding the long term renal consequences of HCT-related AKI, the development of chronic kidney disease (CKD), and CKD care in pediatric patients post-HCT is limited. CKD affects almost 50% of patients after HCT with multifactorial etiology including infection, nephrotoxic medications, transplant-associated thrombotic microangiopathy, graft-versus-host disease, and sinusoidal obstruction syndrome. As renal function declines in CKD, eventually progressing to end stage kidney disease (ESKD), mortality increases and is more than 80% among patients requiring dialysis. Using society guidelines and current literature, this review summarizes definitions and etiologies of and management strategies among patients with AKI and CKD post-HCT with an emphasis on albuminuria, hypertension, nutrition, metabolic acidosis, anemia, and mineral bone disease. The goal of this review is to aid early identification and intervention in patients with renal dysfunction prior to development of ESKD, and to discuss ESKD and renal transplant in these patients post-HCT.

Acute kidney injury and chronic kidney disease in umbilical cord blood transplant recipients

Introduction

Acute kidney injury (AKI) is a frequent early complication post hematopoietic stem cell transplant (HSCT), associated with high morbidity and mortality. Cord blood transplant (CBT) recipients are potentially exposed to more nephrotoxic insults, compared to patients undergoing HSCT from other donor sources. We aimed to identify risk factors for AKI in patients undergoing CBT. We also aimed to identify the impact of AKI on chronic kidney disease (CKD) and survival outcomes by one-year post-CBT.

Methods

Adults and children who underwent a first CBT at our Institution were retrospectively evaluated. AKI was staged according to Kidney Disease Improving Global Outcomes (KDIGO) definitions. Cox regression models were used to estimate the association of demographic factors and post-CBT parameters with the cause-specific hazard of AKI.

Results

We identified 276 patients. Median age was 32 years, 28% (77/276) were children (<18 years) and 129 (47%) were white. A myeloablative conditioning regimen was administered to 243 patients (88%) and 248 (90%) received cyclosporine for GVHD prophylaxis. One-hundred and eighty-six patients (67%) developed AKI by day 60 post-transplant, with 72 (26%) developing severe AKI (stage 2 and 3). In a multivariable analysis, each increase in bilirubin level of 1 mg/dL was associated with a 23% increase in the risk of severe AKI (adjusted HR 1.23, 95% CI 1.13 - 1.34, p<.0001). Conversely, systemic steroid administration appeared to be protective of severe AKI (unadjusted HR 0.36, 95% CI 0.18 - 0.72, p=.004) in a univariate model . Two-hundred-forty-seven patients were evaluable at the one-year time point. Among those, 100 patients (40%) developed CKD one-year post-CBT. Severe AKI was associated with a higher hazard of non-relapse mortality (adjusted HR=3.26, 95% CI 1.65-6.45, p=.001) and overall mortality (adjusted HR=2.28, 95% CI 1.22-4.27, p=.01).

Discussion

AKI is a frequent complication after CBT and is associated with worse outcomes. Questions remain as to the mechanism of the protective role of steroids on kidney function in the setting of CBT.

Kidney Injury in Children after Hematopoietic Stem Cell Transplant

Hematopoietic cell transplant (HCT), used for treatment of many malignant and non-malignant pediatric diseases, is associated with serious complications, limiting this therapy’s benefit. Acute kidney injury (AKI), seen often after HCT, can occur at different stages of the transplant process and contributes to morbidity and mortality after HCT. The etiology of AKI is often multifactorial, including kidney hypoperfusion, nephrotoxicity from immunosuppressive and antimicrobial agents, and other transplant-related complications such as transplant-associated thrombotic microangiopathy and sinusoidal obstructive syndrome. Early recognition of AKI is crucial to prevent further AKI and associated complications. Initial management includes identifying the etiology of AKI, preventing further kidney hypoperfusion, adjusting nephrotoxic medications, and preventing fluid overload. Some patients will require further support with kidney replacement therapy to manage fluid overload and AKI. Biomarkers of AKI, such as neutrophil gelatinase-associated lipocalin can aid in detecting AKI before a rise in serum creatinine, allowing earlier intervention. Long-term kidney dysfunction is also prominent in this population. Therefore, long-term follow-up and monitoring of renal function (glomerular filtration rate, microalbuminuria) is required along with management of hypertension, which can contribute to chronic kidney disease.

Successful Kidney and Hematopoietic Stem Cell Transplantation for Malignant Lymphoma from Different Donors: A Case Report and Literature Review

There are particularly few reports on kidney transplantation after hematopoietic stem cell transplantation (HSCT) for malignant lymphoma, and none of the cases reported a favorable outcome in patients who received kidney transplantation from a different donor to HSCT. In this report, we describe the first case of kidney transplantation from a different donor to HSCT with a successful outcome. Furthermore, we reviewed the previously reported cases. A 59-year-old female patient received an HSCT from her younger brother after chemotherapy for malignant lymphoma. After HSCT, she did not have graft-versus-host disease (GVHD) requiring maintenance treatment. The patient developed chronic kidney disease requiring kidney replacement therapy, probably due to drug toxicity or cardio-renal syndrome. At age 65, she underwent an ABO-compatible, HLA-A, -B, -DR 5/6 mismatched kidney transplantation from her husband. Immunosuppressive therapy with tacrolimus, mycophenolate mofetil, methylprednisolone, and basiliximab was administered. The patient had urinary tract infections at 7 days, 9 weeks, and 4 months after kidney transplantation, and cytomegalovirus antigenemia at 9 weeks after kidney transplantation, which improved with antibiotic and valganciclovir, respectively. When each infection occurred, we weakened immunosuppressive therapy. Four years after kidney transplantation, the patient is in good clinical condition with a serum creatinine of 1.2 mg/dL, without critical infection or malignancy. In this case, we believe that it was important to optimize the immunosuppressive therapy. In addition, from a review of previous cases, it seemed important that there was no GVHD requiring maintenance therapy in order to prevent excessive immunosuppression.

Chronic kidney disease, survival and graft-versus-host-disease/relapse-free survival in recipients of allogeneic hematopoietic stem cell transplant

Background

Advances in allogeneic hematopoietic stem cell transplant (HSCT) have increased patient survival, although substantial treatment-related toxicity remains, including chronic kidney disease (CKD). We assessed the association between CKD and survival and transplant-specific outcomes in HSCT recipients.

Methods

We conducted a retrospective study of all 408 adult patients with allogenic HSCT at Princess Margaret Cancer Centre (Toronto, Canada, 2015–18). We used logistic regression to identify risk factors for CKD at 1 year post-transplant. Associations between CKD at 1 year and overall survival, relapse-free survival, graft-versus-host-disease (GVHD)-free/relapse-free survival, relapse and transplant-related mortality were examined using extended time-varying Cox models. In a sensitivity analysis, we restricted the cohort to survivors at 1 year, using standard Cox proportional hazard models to examine associations between CKD and overall survival, relapse-free survival and GVHD-free/relapse-free survival, and Fine and Gray's competing risk models to determine associations between CKD and relapse/transplant-related mortality.

Results

The prevalence of CKD at 1 year was 19% (46 patients) with median follow-up of 23 months. Multivariable regression identified age at transplant [adjusted OR (aOR) 1.09, 95% confidence interval (95% CI) = 1.05–1.14; P < 0.0001), female gender (aOR 2.83, 95% CI = 1.34–5.97; P = 0.006) and acute kidney injury during the first 100 days (aOR 3.86, 95% CI = 1.70–8.73; P = 0.001) as risk factors for CKD at 1 year. Patients with CKD at 1 year had significantly poorer overall survival than those without CKD, when adjusted for relevant covariates [adjusted HR (aHR) 1.93, 95% CI = 1.02–3.66; P = 0.04 in the time-varying Cox model, and aHR 2.06, 95% CI = 1.04–4.07; P = 0.04 using the standard Cox model]. CKD at 1 year was also associated with worse GVHD-free/relapse-free survival (aHR 1.65, 95% CI = 1.04–2.61; P = 0.03).

Conclusions

CKD adversely affects the long-term prognosis for allogeneic HSCT recipients, with increased mortality risk and worse GVHD-free/relapse-free survival.

Kidney Disease Following Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (SCT) provides a curative option for the treatment of several malignancies. Its growing use is associated with an increased burden of kidney disease. Acute kidney injury is usually seen within the first 100 days of transplantation and has an incidence ranging between 12 and 73%, with the highest rate in myeloablative allogeneic SCT. A large subset of patients after SCT develop chronic kidney disease. They can be broadly classified into thrombotic microangiopathy, nephrotic syndrome, and calcineurin toxicity. Dialysis requirement after SCT is associated with mortality exceeding 80%. Given the higher morbidity and mortality related to development kidney disease, nephrologists need to be aware of the various causes and best treatment options.

Chronic Kidney Disease in Cancer Survivors

As breakthroughs in cancer care are leading to improved long-term outcomes in a subset of advanced cancers, there is a growing population of long-term cancer survivors that are at risk of long-term complications. In this review, we summarize what is known about chronic kidney disease in cancer survivors, focusing on the following high-risk groups: survivors of childhood cancers, stem cell transplant recipients, patients with renal cell carcinoma, patients exposed to cisplatin and other nephrotoxic chemotherapies, and patients receiving immunotherapy for cancer. As new anticancer therapies are developed, more research is needed to understand the long-term risks of kidney function decline and to devise methods to prevent chronic kidney disease.

Outcomes of kidney injury including dialysis and kidney transplantation in pediatric oncology and hematopoietic cell transplant patients

Pediatric oncology and hematopoietic cell transplant (HCT) patients are susceptible to both acute kidney injury (AKI) and chronic kidney disease (CKD). The etiologies of AKI vary but include tumor infiltration, radiation, drug-induced toxicity, and fluid and electrolyte abnormalities including tumor lysis syndrome. HCT patients can also have additional complications such as sinusoidal obstructive syndrome, graft-versus-host disease, or thrombotic microangiopathy. For patients with severe AKI requiring dialysis, multiple modalities can be used successfully, although continuous kidney replacement therapy (CKRT) is often the principal modality for critically ill patients. While increasing numbers of pediatric cancer and HCT patients are now surviving long term, they remain at risk for a number of chronic medical conditions, including CKD. Certain high-risk patients, due to underlying risk factors or treatment-related complications, eventually develop kidney failure and may require kidney replacement therapies. Management of co-morbidities and complications associated with kidney failure, including use of erythropoietin for anemia and potential need for ongoing cancer-related treatment while on dialysis, is an additional consideration in this patient population. Kidney transplantation can be successfully performed in pediatric cancer survivors, although additional features such as specific cancer diagnosis and duration of remission should be considered.

Meta-analysis of AKI to CKD transition in perioperative patients

Background

Recent research shows AKI increases the risk of incident CKD. We hypothesized that perioperative AKI may confer increased risk of subsequent CKD compared to nonperioperative AKI.

Methods

A MEDLINE search was performed for “AKI, CKD, chronic renal insufficiency, surgery, and perioperative” and related terms yielded 5209 articles. One thousand sixty-five relevant studies were reviewed. One thousand six were excluded because they were review, animal, or pediatric studies. Fifty-nine studies underwent full manuscript review by two independent evaluators. Seventeen met all inclusion criteria and underwent analysis. Two-by-two tables were constructed from AKI +/− and CKD +/− data. The R package metafor was employed to determine odds ratio (OR), and a random-effects model was used to calculate weighted ORs. Leave-1-out, funnel analysis, and structured analysis were used to estimate effects of study heterogeneity and bias.

Results

Nonperioperative studies included studies of oncology, percutaneous coronary intervention, and myocardial infarction patients. Perioperative studies comprised patients from cardiac surgery, vascular surgery, and burns. There was significant heterogeneity, but risk of bias was overall assessed as low. The OR for AKI versus non-AKI patients developing CKD in all studies was 4.31 (95% CI 3.01–6.17; p < 0.01). Nonperioperative subjects demonstrated OR 3.32 for developing CKD compared to non-AKI patients (95% CI 2.06–5.34; p < 0.01) while perioperative patients demonstrated OR 5.20 (95% CI 3.12–8.66; p < 0.01) for the same event.

Conclusions

We conclude that studies conducted in perioperative and nonperioperative patient populations suggest similar risk of development of CKD after AKI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00192-6.

Acute Kidney Injury in the Modern Era of Allogeneic Hematopoietic Stem Cell Transplantation

Background and objectives Acute kidney injury (AKI) is a major complication of allogeneic hematopoietic stem cell transplantation, increasing risk of non-relapse mortality. AKI etiology is often ambiguous due to heterogeneity of conditioning/graft-versus-host disease (GVHD) regimens. To date, GVHD and calcineurin inhibitor effects on AKI are not well defined. We aimed to describe AKI and assess pre/post-hematopoietic transplant risk factors in a large recent cohort. Design, setting, participants, and measurements We performed a single-center retrospective study of 616 allogeneic hematopoietic cell transplant recipients from 2014-2017. We defined AKI and CKD based on KDIGO criteria and estimated GFR using CKD-EPI equation. We assessed AKI pre/post-hematopoietic transplant risk factors using cause-specific Cox regression and association of AKI with CKD outcomes using Chi-squared test. AKI was treated as a time-dependent variable in relation to non-relapse mortality. Results Incidence of AKI by day-100 was 64%. Exposure to tacrolimus and other nephrotoxins conferred a higher risk of AKI, but tacrolimus levels were not associated with severity. Reduced intensity conditioning carried higher AKI risk compared to myeloablative conditioning. Most stage 3 AKIs were due to ischemic acute tubular necrosis and CNI nephrotoxicity. Kidney replacement therapy was initiated in 21/616 (3%) of whom 9/21 (43%) recovered and 5/21 (24%) survived to hospital discharge. T-cell depleted transplants, higher baseline albumin, and non-Hispanic ethnicity were associated with lower risk of AKI. CKD developed in 21% (73/345) of patients after 12 months. Non-relapse mortality was higher in those with AKI (HR 2.77, 95% CI: 1.8-4.27). Conclusions AKI post-hematopoietic cell transplant remains a major concern. Risk of AKI was higher with exposure to CNIs. T cell depleted hematopoietic cell transplants and higher albumin had lower risk of AKI. Forty-three percent of patients requiring KRT recovered kidney function. Prospective studies are needed to further assess modification of these risk factors.

Chronic kidney disease ten years after pediatric allogeneic hematopoietic stem cell transplantation

Chronic kidney disease (CKD) is an important sequela of hematopoietic stem cell transplantation (HSCT), but data regarding CKD after pediatric HSCT are limited. In this single center cohort study, we evaluated the estimated glomerular filtration rate (eGFR) dynamics, proteinuria and hypertension in the first decade after HSCT and assessed risk factors for CKD in 216 pediatric HSCT survivors, transplanted 2002-2012. The eGFR decreased from a median of 148 to 116 ml/min/1.73 m² between pre-HSCT to ten years post-HSCT. CKD (KDIGO stages G2 or A2 or more; eGFR under 90 ml/min/1.73m² and/or albuminuria) occurred in 17% of patients. In multivariate analysis, severe prolonged stage 2 or more acute kidney injury (AKI), with an eGFR under 60ml/min/1.73m² and duration of 28 days or more, was the main risk factor for CKD (hazard ratio 9.5, 95% confidence interval 3.4-27). Stage 2 or more AKI with an eGFR of 60ml/min/1.73m² or more and KDIGO stage 2 or more AKI with eGFR under 60ml/min/1.73m² but recovery within 28 days were not associated with CKD. Furthermore, hematological malignancy as HSCT indication was an independent risk factor for CKD. One third of patients had both CKD criteria, one third had isolated eGFR reduction and one third only had albuminuria. Hypertension occurred in 27% of patients with CKD compared to 4.4% of patients without. Tubular proteinuria was present in 7% of a subgroup of 71 patients with available β2-microglobulinuria. Thus, a significant proportion of pediatric HSCT recipients developed CKD within ten years. Our data stress the importance of structural long-term monitoring of eGFR, urine and blood pressure after HSCT to identify patients with incipient CKD who can benefit from nephroprotective interventions.

Correlates and Outcomes of Early Acute Kidney Injury after Hematopoietic Cell Transplantation

BACKGROUND

Patients undergoing hematopoietic cell transplantation (HCT) are at high risk for acute kidney injury (AKI). The etiology of AKI is often multifactorial and includes exposure to antibiotics and calcineurin inhibitors (CNI) for prevention of graft versus host disease.

METHODS

This is a retrospective, single center study which evaluated patients undergoing inpatient HCT at Froedtert Memorial Hospital, Milwaukee, Wisconsin from Jan 1 to Dec 31, 2016. AKI was defined as an increase in serum creatinine > 0.3 mg/dL from baseline value.

RESULTS

The total number of patients included in the study was 280, 64 had AKI and 216 were in the non-AKI group. AKI was noted in 23% patients. Exposure to CNI or vancomycin accounted for the majority of the cases (82%). The median pre-AKI vancomycin trough was elevated in the AKI group at 21.3 mcg/mL (range: 17.4-24.4 mcg/mL) while the pre-AKI CNI trough was lower in the AKI group at 12.3 ng/mL (range: 8.7-14.7 ng/mL).There were also a higher number of ICU transfers (19%) and higher 100 day mortality (15.6%) in the AKI group.

CONCLUSION

AKI is a frequent complication following HCT and is associated with a higher risk of ICU transfer and higher mortality post HCT. While a higher vancomycin trough level may be indicative of a higher risk of AKI, the risk following CNI exposure may not be related to trough levels alone. There may be underlying pharmacogenetic factors which may alter the risk of AKI with CNI use.

Impact of Pretransplantation Renal Dysfunction on Outcomes after Allogeneic Hematopoietic Cell Transplantation

Renal dysfunction is a recognized risk factor for mortality after allogeneic hematopoietic cell transplantation (alloHCT), yet our understanding of the effect of different levels of renal dysfunction at time of transplantation on outcomes remains limited. This study explores the impact of different degrees of renal dysfunction on HCT outcomes and examines whether the utilization of incremental degrees of renal dysfunction based on estimated glomerular filtration rate (eGFR) improve the predictability of the hematopoietic cell transplantation comorbidity index (HCT-CI). The study population included 2 cohorts: cohort 1, comprising patients age ≥40 years who underwent alloHCT for treatment of hematologic malignancies between 2008 and 2016 (n = 13,505; cohort selected given a very low incidence of renal dysfunction in individuals age <40 years), and cohort 2, comprising patients on dialysis at the time of HCT (n = 46). eGFR was measured using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) method. The patients in cohort 1 were assigned into 4 categories-eGFR ≥90 mL/min (n = 7062), eGFR 60 to 89 mL/min (n = 5264), eGFR 45 to 59 mL/min (n = 897), and eGFR <45 mL/min (n=282)-to assess the impact of degree of renal dysfunction on transplantation outcomes. Transplantation outcomes in patients on dialysis at the time of alloHCT were analyzed separately. eGFR <60 mL/min was associated with an increased risk for nonrelapse mortality (NRM) and requirement for dialysis post-HCT. Compared with the eGFR ≥90 group, the hazard ratio (HR) for NRM was 1.46 (P = .0001) for the eGFR 45 to 59 mL/min group and 1.74 (P = .004) for the eGFR <45 mL/min group. Compared with the eGFR ≥90 mL/min group, the eGFR 45 to 59 mL/min group (HR, 2.45; P < .0001) and the eGFR <45 mL/min group (HR, 3.09; P < .0001) had a higher risk of renal failure necessitating dialysis after alloHCT. In addition, eGFR <45 mL/min was associated with an increased overall mortality (HR, 1.63; P < .0001). An eGFR-based revised HCT-CI was also developed and shown to be predictive of overall survival (OS) and NRM, with predictive performance similar to the original HCT-CI. Among 46 patients on dialysis at alloHCT, the 1-year probability of OS was 20%, and that of NRM was 67%. The degree of pretransplantation renal dysfunction is an independent predictor of OS, NRM, and probability of needing dialysis after alloHCT. An eGFR-based HCT-CI is a validated index for predicting outcomes in adults with hematologic malignancies undergoing alloHCT. The outcomes of alloHCT recipients on dialysis are dismal; therefore, one should strongly weigh the significant risks of being on hemodialysis as a factor in determining alloHCT candidacy.

Late Kidney Morbidity and Mortality in Hematopoietic Cell Transplant Survivors

Increasing numbers of patients are undergoing hematopoietic cell transplantation (HCT); however, further characterization of late kidney outcomes in HCT recipients is needed. This study investigated long-term kidney outcomes in HCT survivors and compared the risk of late kidney morbidity/mortality in these survivors with that in non-HCT cancer survivors and the general population. A cohort of long-term (≥2 years) allogeneic and autologous HCT survivors treated for cancer at our institution between 1992 and 2009 (n = 1792) was compared with a non-HCT cancer cohort selected from the state cancer registry (n = 5455) matched on diagnosis, sex, and age at year of cancer diagnosis/HCT (index date). Additional comparisons were made with a matched general population sample drawn from state driver's licensing files (DOL; n = 16,340). Statewide hospital discharge codes and death registry codes (International Classification of Diseases 9/10) were used to identify cases of acute kidney failure (AKF) and chronic kidney disease (CKD) occurring ≥2 years after the index date. Cumulative incidence rates and hazard ratios (HRs; according to multivariable proportional hazard models) estimated the absolute and relative risks of AKF and CKD. Among HCT survivors, we examined the influence of additional characteristics including estimated glomerular filtration rate (eGFR) at 1-year post-HCT. The cumulative incidence rates of late kidney complications were slightly greater in the HCT survivors versus the non-HCT cancer survivors at 10 years after the index date. Both groups were more likely to experience late AKF or CKD morbidity/mortality compared with the general population (AKF: HCT, 9.4%; non-HCT, 7.7%; DOL, 1.8%; CKD: HCT, 5.7%; non-HCT, 5.0%; DOL, 1.2%). Differences between HCT survivors and non-HCT survivors were seen primarily starting 5 years after the index date, with increased hazards for late AKF (HR, 1.4; 95% confidence interval [CI], 1.1 to 1.9) and CKD (HR, 1.9; 95% CI, 1.3 to 2.8). Among allogeneic HCT survivors, the presence of hypertension at <2 years post-HCT was significantly associated with subsequent AKF (HR, 2.9; 95% CI, 1.7 to 5.0) and CKD (HR, 5.2; 95% CI, 2.7 to 10.0) at 2 to 10 years post-HCT, with similar associations seen for autologous HCT survivors. Low eGFR (<60 mL/min/1.73 m²) at 1 year post-HCT was associated with late AKF morbidity/mortality for both allogeneic (HR, 5.3; 95% CI, 2.1 to 13.2) and autologous HCT (HR, 2.7; 95% CI, 1.2 to 6.3) compared with survivors with normal eGFR (>90 mL/min/1.73 m²). Overall, the risk for hospitalization or death from AKF or CKD continued to increase with time from HCT and exceeded that of non-HCT cancer survivors at >5 years after treatment. Appropriate screening and early intervention with medication adjustments or lifestyle modifications in those with hypertension or evidence of abnormal eGFR post-HCT could potentially mitigate this risk.

Onconephrology: The intersections between the kidney and cancer

Onconephrology is a new subspecialty of nephrology that recognizes the important intersections of kidney disease with cancer. This intersection takes many forms and includes drug-induced nephrotoxicity, electrolyte disorders, paraneoplastic glomerulonephritis, and the interactions of chronic kidney disease with cancer. Data clearly demonstrate that, when patients with cancer develop acute or chronic kidney disease, outcomes are inferior, and the promise of curative therapeutic regimens is lessened. This highlights the imperative for collaborative care between oncologists and nephrologists in recognizing and treating kidney disease in patients with cancer. In response to this need, specific training programs in onconephrology as well as dedicated onconephrology clinics have appeared. This comprehensive review covers many of the critical topics in onconephrology, with a focus on acute kidney injury, chronic kidney disease, drug-induced nephrotoxicity, kidney disease in stem cell transplantation, and electrolyte disorders in patients with cancer.

Incidence and mortality of acute kidney injury in patients undergoing hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

While acute kidney injury (AKI) is commonly reported following hematopoietic stem cell transplant (HCT), the incidence and impact of AKI on mortality among patients undergoing HCT are not well described. We conducted this systematic review to assess the incidence and impact of AKI on mortality risk among patients undergoing HCT.

METHODS

Ovid MEDLINE, EMBASE and the Cochrane Databases were searched from database inceptions through August 2019 to identify studies assessing the incidence of AKI and mortality risk among adult patients who developed AKI following HCT. Random-effects and generic inverse variance method of DerSimonian-Laird were used to combine the effect estimates obtained from individual studies.

RESULTS

We included 36 cohort studies with a total of 5144 patients undergoing HCT. Overall, the pooled estimated incidence of AKI and severe AKI (AKI Stage III) were 55.1% (95% confidence interval (CI) 46.6-63.3%) and 8.3% (95% CI 6.0-11.4%), respectively. The pooled estimated incidence of AKI using contemporary AKI definitions (RIFLE, AKIN and KDIGO criteria) was 49.8% (95% CI 41.6-58.1%). There was no significant correlation between study year and the incidence of AKI (P = 0.12) or severe AKI (P = 0.97). The pooled odds ratios of 3-month mortality and 3-year mortality among patients undergoing HCT with AKI were 3.05 (95% CI 2.07-4.49) and 2.23 (95% CI 1.06-4.73), respectively.

CONCLUSION

The incidence of AKI among patients who undergo HCT remains high, and it has not changed over the years despite advances in medicine. AKI after HCT is associated with increased short- and long-term mortality.

Independent risk factors and long-term outcomes for acute kidney injury in pediatric patients undergoing hematopoietic stem cell transplantation: a retrospective cohort study

BACKGROUND

Acute kidney injury (AKI) remains a frequent complication in children undergoing hematopoietic stem cell transplantation (HSCT) and an independent risk factor of the patient's survival and a prognostic factor of progression to chronic kidney disease (CKD). However, the causes of these complications are diverse, usually overlapping, and less well understood.

METHODS

This retrospective analysis was performed in 43 patients (28 boys, 15 girls; median age, 5.5 years) undergoing HSCT between April 2006 and March 2019. The main outcome was the development of AKI defined according to the Pediatric Risk, Injury, Failure, Loss, End-stage Renal Disease (pRIFLE) criteria as ≥ 25% decrease in estimated creatinine clearance. The secondary outcome was the development of CKD after a 2-year follow-up.

RESULTS

AKI developed in 21 patients (49%) within 100 days after HSCT. After adjusting for possible confounders, posttransplant AKI was associated with matched unrelated donor (MUD) (HR, 6.26; P = 0.042), but not total body irradiation (TBI). Of 37 patients who were able to follow-up for 2 years, 7 patients died, but none had reached CKD during the 2 years after transplantation.

CONCLUSIONS

Posttransplant AKI was strongly associated with HSCT from MUD. Although the incidence of AKI was high in our cohort, that of posttransplant CKD was lower than reported previously in adults. TBI dose reduced, GVHD minimized, and infection prevented are required to avoid late renal dysfunction after HSCT in children since their combinations may contribute to the occurrence of AKI.

Long-term Follow-up of Hematopoietic Stem Cell Transplant Survivors: A Focus on Screening, Monitoring, and Therapeutics

Annually, ~50,000 patients undergo hematopoietic stem cell transplantation (HCT) worldwide with almost 22,000 of these patients receiving HCT in the United States. HCT is a curative option for a wide range of hematologic malignancies, and advances in transplantation medicine have resulted in an increase in HCT survivors. It is anticipated that the number of HCT survivors will more than double from 242,000 in 2020 to ~500,000 in 2030. Survivors of HCT are at an increased risk of developing late complications due to exposure to chemotherapy and/or radiation in the pre-, peri-, and post-HCT phases and these cumulative exposures have the potential to damage normal tissue. This tissue damage leads to the early onset of chronic health conditions resulting in premature mortality in HCT survivors, who have a 15-year cumulative incidence of severe or life-threatening chronic health conditions exceeding 40%. Due to the significant burden of morbidity in HCT survivors and the delay in the development of long-term complications, this delicate patient population requires life-long monitoring due to the risk for neuropsychological, cardiac, pulmonary, renal, hepatic, ocular, skeletal, cardiac, endocrine, fertility, and sexual health complications, as well as secondary neoplasms. This review will focus on recent advances in screening, monitoring, and therapeutics for late-occurring or long-term complications in HCT survivors.

ABO-Incompatible Kidney Transplantation After Bone Marrow Transplantation: A Case Report

Many studies have been made on ABO-compatible kidney transplants following hematopoietic stem cell transplantation. However, there have been few reports on ABO-incompatible kidney transplantation following hematopoietic stem cell transplantation (HSCT). We report on the case of a successful ABO-incompatible kidney transplantation with high titers after bone marrow transplantation experienced no infectious episodes. The patient was a 38-year-old man with end-stage kidney disease resulting from interstitial nephritis induced by drug toxicity or graft-vs-host disease (GVHD). He had received allogeneic bone marrow transplantation from a human leukocyte antigen-identical unrelated donor to treat chronic myelogenous leukemia. The patient with high anti-B antibody titers (IgM 1:1024 IgG 1:256) received a desensitization protocol consisting of 2 doses of rituximab and 5 courses of plasmapheresis. The patient had prolonged depletion of circulating B cells 2 years after the transplant and was infected with cytomegalovirus viremia, pneumocystis jiroveci pneumonia, and adenovirus urinary tract infection at 2, 3, and 17 months post-transplant, respectively. Currently, at 6 years after his transplant, the patient has had no rejection and is in good clinical condition with only mild renal insufficiency. Our results suggest that ABO-incompatible kidney transplantation may be an effective renal replacement therapy for patients with end-stage kidney disease after HSCT, but desensitization in combination with immunosuppressants could lead to a state of over-immunosuppression, causing various infections.

Modified diagnostic criteria, grading classification and newly elucidated pathophysiology of hepatic SOS/VOD after haematopoietic cell transplantation

Sinusoidal obstruction syndrome (SOS), previously known as hepatic veno-occlusive disease (VOD), remains a multi-organ system complication following haematopoietic cell transplantation (HCT). When SOS/VOD is accompanied by multi-organ dysfunction, overall mortality rates remain >80%. However, the definitions related to the diagnosis and grading of SOS/VOD after HCT are almost 25 years old and require new and contemporary modifications. Importantly, the pathophysiology of SOS/VOD, including the contribution of dysregulated inflammatory and coagulation cascades as well as the critical importance of liver and vascular derived endothelial dysfunction, have been elucidated. Here we summarise new information on pathogenesis of SOS/VOD; identify modifiable and unmodifiable risk factors for disease development; propose novel, contemporary and panel opinion-based diagnostic criteria and an innovative organ-based method of SOS/VOD grading classification; and review current approaches for prophylaxis and treatment of SOS/VOD. This review will hopefully illuminate pathways responsible for drug-induced liver injury and manifestations of disease, sharpen awareness of risk for disease development and enhance the timely and correct diagnosis of SOS/VOD post-HCT.

Acute Kidney Injury and CKD Associated with Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation is a life-saving therapy for many patients with cancer, as well as patients with some nonmalignant hematologic disorders, such as aplastic anemia, sickle cell disease, and certain congenital immune deficiencies. Kidney injury directly associated with stem cell transplantation includes a wide range of structural and functional abnormalities, which may be vascular (hypertension, thrombotic microangiopathy), glomerular (albuminuria, nephrotic glomerulopathies), and/or tubulointerstitial. AKI occurs commonly after stem cell transplant, affecting 10%-73% of patients. The cause is often multifactorial and can include sepsis, nephrotoxic medications, marrow infusion syndrome, hepatic sinusoidal obstruction syndrome, thrombotic microangiopathy, infections, and graft versus host disease. The risk of post-transplant kidney injury varies depending on patient characteristics, type of transplant (allogeneic versus autologous), and choice of chemotherapeutic conditioning regimen (myeloablative versus nonmyeloablative). Importantly, AKI is associated with substantial morbidity, including the need for KRT in approximately 5% of patients and the development of CKD in up to 60% of transplant recipients. AKI has been associated universally with higher all-cause and nonrelapse mortality regardless of transplant type, and studies have consistently shown extremely high (>80%) mortality rates in those patients requiring acute dialysis. Accordingly, prevention, early recognition, and prompt treatment of kidney injury are essential to improving kidney and patient outcomes after hematopoietic stem cell transplantation, and for realizing the full potential of this therapy.

Risk Factors for Acute Kidney Injury and Chronic Kidney Disease following Allogeneic Hematopoietic Stem Cell Transplantation for Hematopoietic Malignancies

BACKGROUND

Acute kidney injury (AKI) and chronic kidney disease (CKD) are considered common complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

OBJECTIVES AND METHOD

In this study, 114 patients who had undergone allo-HSCT were retrospectively analyzed to investigate the risk factors for onset of posttransplant AKI and CKD as defined by the new Kidney Disease Improving Global Outcomes criteria.

RESULTS

Seventy-four patients (64.9%) developed AKI and 25 (21.9%) developed CKD. The multivariate analysis showed that the risk factors for developing stage 1 or higher AKI were age ≥46 years at the time of transplant (p = 0.001) and use of ≥3 nephrotoxic drugs (p = 0.036). For CKD, the associated risk factors were disease status other than complete remission at the time of transplantation (p = 0.018) and onset of AKI after transplant (p = 0.035). The 5-year overall survival (OS) was significantly reduced by development of AKI (p < 0.001), but not CKD. Posttransplant AKI significantly increased the 5-year nonrelapse mortality (p < 0.001), whereas posttransplant CKD showed an increasing tendency, but the difference was not significant.

CONCLUSIONS

Posttransplant AKI impacts OS, significantly increases the risk of CKD, and is significantly associated with disseminated intravascular coagulation and use of ˃3 nephrotoxic drugs.

Potential drug-drug interactions and nephrotoxicity in hematopoietic stem cell transplant adult recipients during bone marrow transplantation unit stay

PURPOSE

Studies have documented potential drug-drug interactions (pDDIs) occurring in cancer patients mainly with solid malignancies, either in the ambulatory or hospital settings. While hematopoietic stem cell transplant (HSCT) patients during their bone marrow transplantation unit (BMTU) stay have rather complex medical regimens combining chemotherapy, anti-infectious agents, immunosuppressive agents, and supportive-care drugs, studies on potential DDIs are lacking. Our objective was to evaluate the prevalence and the density of pharmacokinetic and pharmacodynamic potential DDIs, and the evolution of the renal function in hematopoietic stem cell transplant (HSCT) adult recipients during their BMTU stay.

METHODS

Retrospective study in 31 adult patients consecutively admitted to the BMTU.

RESULTS

Prevalence of pharmacokinetic interactions was ten times lower than the pharmacodynamic interactions. The contraindications were rare, and only of pharmacokinetic origin. The main drugs involved in pharmacokinetic DDIs were ciclosporine, methotrexate, esomeprazole, tramadol, and vincristine. The median number of potential nephrotoxicity-related DDIs per patient was 7 and the median number of days during which nephrotoxicity-related DDIs potentially occurred was 77 days per patient. The decrease in glomerular filtration rate (GFR) throughout the BMTU stay (mean decrease of 13 ml/min) was correlated with the number of days of potential nephrotoxic drug interactions.

CONCLUSIONS

Potential DDIs in HCST patients in BMTU were quite common. The DDIs from pharmacokinetic origin were less frequent, but of higher grade, than those of pharmacodynamic origin. The decrease in GFR suggests that the density of potential nephrotoxic drug interactions may be an issue to be considered in these patients.

Kidney transplantation for treatment of end-stage kidney disease after haematopoietic stem cell transplantation: case series and literature review

BACKGROUND

The safety of kidney transplantation (KT) for end-stage kidney disease (ESKD) after haematopoietic stem cell transplantation (HSCT) for haematological disease has not been investigated thoroughly.

METHODS

In this retrospective multicentre study, we investigated the clinical courses of six ESKD patients that received KT after HSCT for various haematological diseases. Data for six such patients were obtained from three institutions in our consortium.

RESULTS

Two patients with chronic myeloid leukaemia, one with refractory aplastic anaemia and another one with acute lymphocytic leukaemia received bone marrow transplantation. One patients with acute lymphocytic leukaemia received umbilical cord blood transplantation, and one with mantle cell lymphoma received peripheral blood stem cell transplantation. The patients developed ESKD at a median of 133 months after HSCT. Two patients who received KT and HSCT from the same donor were temporarily treated with immunosuppressive drugs. The other patients received KT and HSCT from different donors and were treated with antibody induction using our standard regimens. For one patient with ABO-incompatible transplantation, we added rituximab, splenectomy, and plasmapheresis. In the observational period at a median of 51 months after KT, only one patient experienced acute T-cell-mediated rejection. Four patients underwent hospitalization because of infection and fully recovered. No patient experienced recurrence of their original haematological disease. All patients survived throughout the observational periods, and graft functions were preserved.

CONCLUSIONS

Despite the high infection frequency, survival rates and graft functions were extremely good in patients compared with previous studies. Therefore, current management contributed to favourable outcomes of these patients.

Renal dysfunction within 90 days of FluBu4 predicts early and late mortality

Myeloablative conditioning regimens with significant extramedullary toxicity result in high rates of renal dysfunction including acute kidney injury (AKI). Here we examine the incidence and impact of a reduced creatinine clearance (below 60 ml/min) before day 90 (early renal dysfunction, ERD) in patients receiving the reduced toxicity fludarabine/i.v. busulfan (FluBu4) regimen prior to allogeneic transplant. Of 91 patients receiving FluBu4, 62 (68%) developed ERD. ERD resulted in worse overall survival (OS, 2.2 years versus median not reached, p = 0.04) and progression-free survival (PFS, 1.6 years versus median not reached, p = 0.02). This was due to a higher relapse rate (34% versus 14%, p = 0.03) in the ERD group. In time-dependent Cox proportional hazards models adjusted for age, ERD was associated with worse OS (hazard ratio [HR] 2.67, 95% confidence interval [CI] 1.06-4.21, p = 0.043) and PFS (HR 2.52, 95% CI 1.17-4.28, p = 0.030). Patients with ERD surviving 1 year had an increased risk of chronic kidney disease (CKD, OR 10; 95% CI 1.4-112.6, p = 0.0181), which was associated with worse survival (3.2 years versus median not reached, p = 0.002). ERD after FluBu4 is therefore a poor prognostic sign resulting in increased relapse, worse OS, and high risk of CKD at 1 year.

Changes in Glomerular Filtration Rate and Impact on Long-Term Survival among Adults after Hematopoietic Cell Transplantation: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES

Kidney injury is a significant complication for patients undergoing hematopoietic cell transplantation (HCT), but few studies have prospectively examined changes in GFR in long-term survivors of HCT. We described the association between changes in GFR and all-cause mortality in patients up to 10 years after HCT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a prospective, observational cohort study of adult patients undergoing HCT at the Fred Hutchinson Cancer Center in Seattle, Washington from 2003 to 2015. Patients were followed from baseline, before conditioning therapy, until a maximum of 10 years after transplant. We used Cox proportional hazard models to examine the association between creatinine eGFR and all-cause mortality. We used time-dependent generalized estimating equations to examine risk factors for decreases in eGFR.

RESULTS

A total of 434 patients (median age, 52 years; range, 18-76 years; 64% were men; 87% were white) were followed for a median 5.3 years after HCT. The largest decreases in eGFR occurred within the first year post-transplant, with the eGFR decreasing from a median of 98 ml/min per 1.73 m2 at baseline to 78 ml/min per 1.73 m2 by 1 year post-HCT. Two thirds of patients had an eGFR<90 ml/min per 1.73 m2 at 1 year after transplant. When modeled as a continuous variable, as eGFR declined from approximately 60 ml/min per 1.73 m2, the hazard of mortality progressively increased relative to a normal eGFR of 90 ml/min per 1.73 m2 (P<0.001). For example, when compared with an eGFR of 90 ml/min per 1.73 m2, the hazard ratios for eGFR of 60, 50, and 40 ml/min per 1.73 m2 are 1.15 (95% confidence interval, 0.87 to 1.53), 1.68 (95% confidence interval, 1.26 to 2.24), and 2.67 (95% confidence interval, 1.99 to 3.60), respectively. Diabetes, hypertension, acute graft versus host disease, and cytomegalovirus infection were independently associated with a decline in GFR, whereas calcineurin inhibitor levels, chronic graft versus host disease, and albuminuria were not.

CONCLUSIONS

Adult HCT recipients have a high risk of decreased eGFR by 1 year after HCT. Although eGFR remains fairly stable thereafter, a decreased eGFR is significantly associated with higher risk of mortality, with a progressively increased risk as eGFR declines.

An Overview of Kidney Disease Following Hematopoietic Cell Transplantation

Hematopoietic stem cell transplantation (SCT) recipients are exposed to a large amount of anti-cancer drugs, immunosuppressors, and irradiation during the peri-SCT period. Thus, they have to overcome serious adverse events related to unavoidable but toxic procedures, including organ disorders. In particular, acute kidney injury (AKI) is one of the most critical complications, because it influences the mortality of patients. A few patients who survive AKI may develop nephrotic syndrome, and precedent AKI is also closely associated with chronic and progressive loss of the renal function in post-SCT patients. These kidney diseases place a heavy burden on SCT patients, both medically and economically. Therefore, hematologists who evaluate SCT should be fully aware of the development of these kidney diseases after SCT. We herein review the common course of kidney disease development following allogeneic SCT to provide healthcare professionals with practical information on renal disease in SCT patients.

Chronic Kidney Disease in Long-Term Survivors after Allogeneic Hematopoietic Stem Cell Transplantation: Retrospective Analysis at a Single Institute

The number of patients eligible for allogeneic stem cell transplantation (allo-HSCT) has increased because of improvements in transplantation procedures. Among long-term survivors of allo-HSCT, chronic kidney disease (CKD) is a major cause of morbidity. We retrospectively analyzed the clinical data of 106 consecutive patients with a median age of 43 years (range, 17 to 73) who had undergone allo-HSCT at our institution between January 2001 and September 2009. Patients who died within 5 years after transplantation or had CKD at the time of transplantation were excluded from study. CKD was defined as a persistent decrease in the estimated glomerular filtration rate to below 60 mL/min/1.73 m². CKD occurred in 32 patients (30.2%) at a median time of 55 months after transplantation. Three patients required maintenance hemodialysis. In multivariate analysis older age at the time of transplantation (hazard ratio [HR], 1.07/year; 95% confidence interval [CI], 1.02 to 1.13) and a history of acute kidney injury (AKI) within 100 days after transplantation (HR, 6.30; 95% CI, 2.21 to 17.9) were significant risk factors for CKD. Conditioning regimen, stem cell source, or the presence of acute/chronic GVHD was not significantly associated with CKD in this study. Patients with CKD had a lower overall survival rate (HR, 4.11; 95% CI, 1.3 to 13.0) than patients without CKD. Careful monitoring of renal function is required for long-term survivors after allo-HSCT, especially in patients who have experienced AKI and in older patients.

Long-term renal outcome after allogeneic hemopoietic stem cell transplant: A comprehensive analysis of risk factors in an Asian patient population

Allogeneic hemopoietic stem cell transplantation (allo-HSCT) poses a significant challenge to renal function due to multiple drug- and complication-related renal toxicity. In this single-center series of 216 adult Asian patients with a long and complete follow-up, 41 developed chronic kidney disease (CKD) giving a cumulative incidence of 19.0% at 25 years (median follow-up duration 7.84 years, range 2.0-27.7 years), but only two of the 41 patients reached stage 4 CKD and another two required dialysis. In contrast, acute kidney injury occurred in most patients, where glomerular filtration rate (GFR) suffered a mean fall of 50 mL/min/1.73 m² at 6 months post-transplant compared with baseline. Suppression of renal function may last beyond 6 months but is potentially reversible, although not to baseline level in most patients. Analysis of a comprehensive range of 18 risk factors showed that older age, lower GFR at transplant, unrelated donor, diagnosis of AML, presence of diabetes mellitus at transplant, and duration of foscarnet use were significantly associated with CKD development, with the first three remaining as independent risks for CKD in multivariate analysis. Long-term survival is not affected by renal function, being 78.6% as compared to 85.5% for patients with low vs normal GFR at 2 years, respectively.

The Role of Acute Kidney Injury in Chronic Kidney Disease

There is increasing recognition that acute kidney injury (AKI) and chronic kidney disease (CKD) are closely linked and likely promote one another. Underlying CKD now is recognized as a clear risk factor for AKI because both decreased glomerular filtration rate and increased proteinuria have been shown to be associated strongly with AKI. A growing body of literature also provides evidence that AKI accelerates the progression of CKD. Individuals who suffered dialysis-requiring AKI are particularly vulnerable to worse long-term renal outcomes, including end-stage renal disease. The association between AKI and subsequent renal function decline is amplified by pre-existing severity of CKD, higher stage of AKI, and the cumulative number of AKI episodes. However, residual confounding and ascertainment bias may partly explain the epidemiologic association between AKI and CKD in observational studies. As the number of AKI survivors increases, we need to better understand other clinically important outcomes after AKI, identify those at highest risk for the most adverse sequelae, and develop strategies to optimize their care.

Late Effects after Umbilical Cord Blood Transplantation in Very Young Children after Busulfan-Based, Myeloablative Conditioning

Infants and young children who undergo allogeneic cord blood transplantation (CBT) are at increased risk for late effects because of exposure of developing organs to chemotherapy and radiation therapy typically used in transplant conditioning regimens. Busulfan (Bu)-based myeloablative regimens were developed to eliminate radiation exposure in these young children with the hope that late effects would be minimized. We now describe the late effects in 102 consecutive patients surviving a minimum of 5 years (median follow-up, 12.9 years) post-CBT. Patients were conditioned with high-dose chemotherapy using Bu-containing regimens. No patient received total body irradiation. The median age at transplant was 1 year (range, .1 to 2). Diagnoses included inherited metabolic diseases (59.8%), leukemia (17.6%), congenital immune deficiency (20.2%), bone marrow failure/myelodysplastic syndrome (3.9%), and hemoglobinopathy (2%). Among patients surviving 5 years, the overall survival rate at 10 years post-CBT was 93% (95% CI, 84.9 to 96.8). Virtually all patients (98%) experienced at least 1 significant late effect. Most (83.3%) experienced 2 or more late effects, and more than half of the patients (64.7%) experienced 3 or more late effects. The most commonly observed late effects included dental problems (92.2%), short stature (55.9%), cognitive deficits (53.6%), pulmonary dysfunction (18.6%), and abnormal pubertal development (27.9%). This is the first report of late effects of Bu-based conditioning in a cohort of very young patients at the time of transplant. These results will inform clinical care guidelines for long-term follow-up and add to the growing information regarding outcomes of hematopoietic stem cell transplantation.

Early-onset acute kidney injury is a poor prognostic sign for allogeneic SCT recipients

Acute kidney injury (AKI) following stem-cell transplantation (SCT) contributes to a poor prognosis, yet its impact may vary depending on the timing of AKI onset. A prospective cohort study was performed to understand the significance of the onset timing in 103 allogeneic SCT (allo-SCT) recipients. AKI prior to stem-cell engraftment was defined as early AKI and subsequently occurring AKI as late AKI. Propensity score (PS) for early AKI was calculated using a logistic regression model to reduce confounding effects related to differences in clinical background between the early and late AKI groups. The cumulative incidences of early and late AKI were 22.3% and 54.9%, respectively. Non-relapse mortality (NRM) was 39.1% and 7.0%, and overall survival (OS) was 56.5% and 90.9% in early and late AKI at 100 days after AKI, respectively (P<0.001). The cumulative incidence of chronic kidney disease (CKD) over 2 years after SCT was 41.5% and 19.1% in early and late AKI, respectively (P=0.048). Logistic regression analysis adjusted for the PS showed that early AKI was significantly associated with OS (odds ratio (95% confidence interval); 4.63 (1.15-21.4), P=0.031) but with neither NRM (1.25 (0.28-5.33), P=0.766) nor CKD (1.85 (0.41-8.60), P=0.422). In conclusion, early AKI may portend a poor survival for allo-SCT recipients.

Long-term risk of chronic kidney disease and mortality in children after acute kidney injury: a systematic review

BACKGROUND

Acute kidney injury (AKI) is associated with significant short-term morbidity and mortality in children. However, the risk for long-term outcomes after AKI is largely unknown.

METHODS

We performed a systematic review and meta-analysis to determine the cumulative incidence rate of proteinuria, hypertension, decline in glomerular filtration rate (GFR), and mortality after an episode of AKI. After screening 1934 published articles from 1985-2013, we included 10 cohort studies that reported long-term outcomes after AKI in children.

RESULTS

A total of 346 patients were included in these studies with a mean follow-up of 6.5 years (range 2-16) after AKI. The studies were of variable quality and had differing definitions of AKI with five studies only including patients who required dialysis during an AKI episode. There was a substantial discrepancy in the outcomes across these studies, most likely due to study size, disparate outcome definitions, and methodological differences. In addition, there was no non-AKI comparator group in any of the published studies. The cumulative incidence rates for proteinuria, hypertension, abnormal GFR (<90 ml/min/1.73 m2), GFR < 60 ml/min/1.73 m2, end stage renal disease, and mortality per 100 patient-years were 3.1 (95% CI 2.1-4.1), 1.4 (0.9-2.1), 6.3 (5.1-7.5), 0.8 (0.4 -1.4), 0.9 (0.6-1.4), and 3.7 (2.8-4.5) respectively.

CONCLUSIONS

AKI appears to be associated with a high risk of long-term renal outcomes in children. These findings may have implications for care after an episode of AKI in children. Future prospective studies with appropriate non-AKI comparator groups will be required to confirm these results.

Urinary liver-type fatty acid-binding protein linked with increased risk of acute kidney injury after allogeneic stem cell transplantation

Stem cell transplantation (SCT) involves a great risk of acute kidney injury (AKI). Urinary liver-type fatty acid-binding protein (uL-FABP) is a sensitive biomarker to detect kidney damage before an increase in serum creatinine (Cr); however, the utility of uL-FABP is not fully understood in the platform of SCT. A prospective study was conducted in 84 allogeneic SCT recipients to ascertain a link between the uL-FABP level before preparative procedures and AKI incidence after SCT. The association between them was analyzed using Gray's method and a multivariate Fine-Gray proportional hazards regression model. The recipients were stratified into high and low uL-FABP groups, according to the reference value for healthy subjects (8.4 μg/g Cr). AKI developed more frequently in the high (n = 20) than low (n = 64) group (55.0% versus 26.6% at day 30, P = .005), and high uL-FABP was an independent risk for the emergence of AKI (hazard ratio, 2.78; 95% confidence interval, 1.24 to 6.22, P = .01). In conclusion, increased baseline uL-FABP, which may indicate previous incipient kidney injury, is linked with a high risk of AKI after allogeneic SCT.

Predicting Adverse Health Outcomes in Long-Term Survivors of a Childhood Cancer

More than 80% of children and young adults diagnosed with invasive cancer will survive five or more years beyond their cancer diagnosis. This population has an increased risk for serious illness- and treatment-related morbidity and premature mortality. A number of these adverse health outcomes, such as cardiovascular disease and some second primary neoplasms, either have modifiable risk factors or can be successfully treated if detected early. Absolute risk models that project a personalized risk of developing a health outcome can be useful in patient counseling, in designing intervention studies, in forming prevention strategies, and in deciding upon surveillance programs. Here, we review existing absolute risk prediction models that are directly applicable to survivors of a childhood cancer, discuss the concepts and interpretation of absolute risk models, and examine ways in which these models can be used applied in clinical practice and public health.

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.

Acute kidney injury in the neonate

Critically ill neonates are at risk for acute kidney injury (AKI). AKI has been associated with increased risk of morbidity and mortality in adult and pediatric patients, and increasing evidence suggests a similar association in the neonatal population. This article describes the current AKI definitions (including their limitations), work on novel biomarkers to define AKI, diagnosis and management strategies, long-term outcomes after AKI, and future directions for much-needed research in this important area.

Assessment and management of renal impairment in chemotherapy for urogenital cancer

The method of diagnosing chronic kidney disease by simple estimated glomerular filtration rate equations has demonstrated a high prevalence of chronic kidney disease among the genitourinary cancer patients. Approximately 30-50% of urothelial cancer patients have Grade 3 chronic kidney disease before chemotherapy, and the rate increases to around 80% in upper urinary tract cancer patients who have undergone radical surgery. Several gold-standard treatments, including cisplatin for urothelial/testicular tumors and anti-vascular endothelial growth factor therapy for kidney cancers, are known to be associated with the development of renal impairment. However, which renal function assessments are best to select a chemotherapy regimen remain unknown. Most testicular tumor patients are cured by intensive combined chemotherapy with cisplatin, but chemotherapy can induce chronic kidney disease in testicular cancer survivors. The prevalence of Stage 3 chronic kidney disease among the testicular cancer survivors is between 10 and 20%. Thus, the estimated glomerular filtration rate assessment is a useful tool for monitoring the development of chronic kidney disease among the cancer survivors, and assessment of renal function is mandatory before the treatment of these genitourinary cancer patients.

New-onset microalbuminuria following allogeneic myeloablative SCT is a sign of near-term decrease in renal function

The emergence of microalbuminuria following conditioning chemotherapy may predict the development of renal dysfunction. To confirm this, a 1-year retrospective cohort study was conducted in 31 myeloablative allogeneic SCT patients who received five consecutive measurements of albuminuria before conditioning therapy and on days 0, 7, 14 and 28 following SCT. The cohort had neither microalbuminuria nor renal dysfunction at baseline. Microalbuminuria was defined as an albumin-creatinine (Cr) ratio over 30 mg/g, and renal dysfunction was as an estimated glomerular filtration rate <60 mL/min per 1.73 m(2). Cumulative incidence of renal dysfunction over time was analyzed by the Kaplan-Meier method. Multivariate Cox proportional hazards analysis was used to examine an association of de novo microalbuminuria with the incidence of renal dysfunction. In all, 16 patients (52%) developed microalbuminuria that was positive at least two times among the four measurements after SCT. The actuarial occurrence of chronic kidney disease was significantly higher in patients who developed microalbuminuria than in those who did not. Incidence of microalbuminuria had a significant risk of subsequent renal dysfunction (hazard ratio (95% confidence interval), 7.3 (1.2-140)). In conclusion, de novo microalbuminuria following conditioning therapy is a warning of near-term loss of renal function.

Risk factors for chronic kidney disease after chemotherapy for testicular cancer

OBJECTIVE

To elucidate the patterns of and risk factors for deterioration of renal function after chemotherapy in metastatic testicular cancer survivors using the estimated glomerular filtration rate.

METHODS

A total of 96 patients who were treated with cisplatin-based chemotherapy for metastatic testicular cancer between January 1981 and December 2010 were enrolled in this study. The estimated glomerular filtration rate was based on the serum creatinine concentration using the formula of the Japanese Society of Nephrology. Risk factors for chronic kidney disease were examined by multivariate logistic-regression analysis.

RESULTS

The median follow-up period was 70 months (range 15-342). The median pretreatment estimated glomerular filtration rate was 98 mL/min/1.73 m(2) (range 44-216), and it gradually decreased for 1 year after the end of chemotherapy, although there was no significant change in estimated glomerular filtration rate beyond 1 year. One year after chemotherapy, 22 of 96 patients (23%) showed chronic kidney disease (less than 60 mL/min/1.73 m(2) estimated glomerular filtration rate). The multivariate analysis showed that the patients with mild renal damage (estimated glomerular filtration rate 60-89 mL/min/1.73 m(2) ) and elevated blood pressure (higher than 130/80 mmHg) before treatment had a significant risk with odds ratios of 2.63 (95% confidence interval 1.09-6.73) and 4.22 (95% confidence interval 1.45-12.6), respectively.

CONCLUSIONS

Close monitoring of renal function is important for at least 1 year after chemotherapy for testicular cancer, especially in patients having elevated blood pressure and/or mild renal damage before chemotherapy.