Sangeeta Hingorani

Reduced mortality after allogeneic hematopoietic cell transplantation

BACKGROUND Over the past decade, advances have been made in the care of patients undergoing transplantation. We conducted a study to determine whether these advances have improved the outcomes of transplantation. METHODS We analyzed overall mortality, mortality not preceded by relapse, recurrent malignant conditions, and the frequency and severity of major complications of transplantation, including graft-versus-host disease (GVHD) and hepatic, renal, pulmonary, and infectious complications, among 1418 patients who received their first allogeneic transplants at our center in Seattle in the period from 1993 through 1997 and among 1148 patients who received their first allogeneic transplants in the period from 2003 through 2007. Components of the Pretransplant Assessment of Mortality (PAM) score were used in regression models to adjust for the severity of illness at the time of transplantation. RESULTS In the 2003-2007 period, as compared with the 1993-1997 period, we observed significant decreases in mortality not preceded by relapse, both at day 200 (by 60%) and overall (by 52%), the rate of relapse or progression of a malignant condition (by 21%), and overall mortality (by 41%), after adjustment for components of the PAM score. The results were similar when the analyses were limited to patients who received myeloablative conditioning therapy. We also found significant decreases in the risk of severe GVHD; disease caused by viral, bacterial, and fungal infections; and damage to the liver, kidneys, and lungs. CONCLUSIONS We found a substantial reduction in the hazard of death related to allogeneic hematopoietic-cell transplantation, as well as increased long-term survival, over the past decade. Improved outcomes appear to be related to reductions in organ damage, infection, and severe acute GVHD. (Funded by the National Institutes of Health.).

Design of the nephrotic syndrome study network (NEPTUNE) to evaluate primary glomerular nephropathy by a multidisciplinary approach

The Nephrotic Syndrome Study Network (NEPTUNE) is a North American multi-center collaborative consortium established to develop a translational research infrastructure for Nephrotic Syndrome. This includes a longitudinal observational cohort study, a pilot and ancillary studies program, a training program, and a patient contact registry. NEPTUNE will enroll 450 adults and children with minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy for detailed clinical, histopathologic, and molecular phenotyping at the time of clinically-indicated renal biopsy. Initial visits will include an extensive clinical history, physical examination, collection of urine, blood and renal tissue samples, and assessments of quality of life and patient-reported outcomes. Follow-up history, physical measures, urine and blood samples, and questionnaires will be obtained every 4 months in the first year and bi-annually, thereafter. Molecular profiles and gene expression data will be linked to phenotypic, genetic, and digitalized histologic data for comprehensive analyses using systems biology approaches. Analytical strategies were designed to transform descriptive information to mechanistic disease classification for Nephrotic Syndrome and to identify clinical, histological, and genomic disease predictors. Thus, understanding the complexity of the disease pathogenesis will guide further investigation for targeted therapeutic strategies.

Chronic Kidney Disease in Long-Term Survivors of Hematopoietic Cell Transplantation: Epidemiology, Pathogenesis, and Treatment

High-dose myeloablative hematopoietic cell transplantation is becoming an increasingly common treatment modality for a variety of diseases. Patient survival may be limited by substantial treatment-related toxicities, including chronic kidney disease (CKD). Although the majority of CKD after transplantation is idiopathic, thrombotic microangiopathic syndromes and nephrotic syndrome have been described. Epidemiology, pathogenesis, and potential treatment options for the various clinical syndromes that are associated with CKD in hematopoietic cell transplantation patients is reviewed. As the indications for and the numbers of transplants that are performed worldwide increases, so will the burden of CKD. The nephrologists and oncologists will have to work together to identify patients who are at risk for CKD early to prevent its development and progression to end-stage kidney disease.

Renal Thrombotic Microangiopathy after Hematopoietic Cell Transplant: Role of GVHD in Pathogenesis

BACKGROUND AND OBJECTIVES Thrombotic microangiopathy (TMA) is a known complication of hematopoietic cell transplantation (HCT). The etiology and diagnosis of TMA in this patient population is often difficult because thrombocytopenia, microangiopathic hemolytic anemia, and kidney injury occur frequently in HCT recipients, and are the result of a variety of insults. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS The authors reviewed renal pathology and clinical data from HCT patients to determine the prevalence of TMA and to identify correlative factors for developing TMA in the kidney. Kidney tissue was evaluated from 314 consecutive autopsies on patients who died after their first HCT (received between 1992 and 1999). Renal pathology was classified into three groups: (1) no renal thrombus (65%), (2) TMA (20%), and (3) isolated thrombosis (15%). Logistic regression models estimated the associations between each histologic category and clinical parameters: donor and recipient gender, patient age, human leukocyte antigen (HLA) matching of the donor and recipient, total body irradiation (TBI), acute graft versus host disease (GVHD), acute kidney injury, medications, and viral infections. RESULTS In a multivariate analysis, TMA correlated with acute GVHD grades II to IV, followed by female recipient/male donor, TBI > 1200 cGy, and adenovirus infection. Grades II to IV acute GVHD and female gender were associated with isolated renal thrombus. CONCLUSIONS TMA in HCT recipients is associated with acute GVHD grades II to IV, recipient/donor mismatch, TBI > 1200 cGy, and adenovirus infection.

National Cancer Institute, National Heart, Lung and Blood Institute/Pediatric Blood and Marrow Transplantation Consortium First International Consensus Conference on Late Effects after Pediatric Hematopoietic Cell Transplantation: The Need for Pediatric-Specific Long-Term Follow-up Guidelines

Existing standards for screening and management of late effects occurring in children who have undergone hematopoietic cell transplantation (HCT) include recommendations from pediatric cancer networks and consensus guidelines from adult-oriented transplantation societies applicable to all HCT recipients. Although these approaches have significant merit, they are not pediatric HCT-focused, and they do not address post-HCT challenges faced by children with complex nonmalignant disorders. In this article we discuss the strengths and weaknesses of current published recommendations and conclude that pediatric-specific guidelines for post-HCT screening and management would be beneficial to the long-term health of these patients and would promote late effects research in this field. Our panel of late effects experts also provides recommendations for follow-up and therapy of selected post-HCT organ and endocrine complications in pediatric patients.

Hypertension in Long-Term Survivors of Pediatric Hematopoietic Cell Transplantation

A retrospective study was conducted to determine risk factors for the development of hypertension (HTN) and to describe the prevalence among long-term survivors of pediatric hematopoietic cell transplant (HCT). Records of 689 pediatric patients who survived 5 years or more after HCT, from 1969 to 2004, were reviewed for development of HTN. In children, HTN was defined as either a systolic or diastolic pressure > or =95th percentile according to age, sex, and height. In adults, HTN was defined as systolic pressures > or =140 mmHg and/or diastolic pressures > or =90 mmHg in nondiabetic adults and systolic pressures > or =130 and/or diastolic pressures > or =80 in diabetic adults. Multivariate Cox regression models were used to estimate the hazard ratio (HR) of risk factors associated with HTN. All patients included were off immunosuppressive therapy. Patients had been treated with total body irradiation (TBI) (n = 482, 70%) or non-TBI regimens (n = 207, 30%) followed by autologous (n = 87), related (n = 484), or unrelated donor HCT (n = 118). Median follow-up was 16 (range: 5-36) years. HTN developed in 120 patients with a 30-year cumulative incidence of 36%. Risk factors associated with HTN were acute kidney injury (AKI; doubling of baseline creatinine by day 100 after HCT) (HR = 2.5; 95% confidence interval (CI) 1.7-3.7, P < .0001), TBI in the preparative regimen (HR = 2.1; 95% CI 1.3-3.3, P = .001), donor type (autologous HR = 2.4; 95% CI 1.3-4.4 and unrelated donor HR = 1.8; 95% CI 1.0-3.2, P = .01), obesity (HR = 4.0; 95% CI 2.3-6.8, P < .0001), diabetes (HR = 6.7; 95% CI 3.9-11.0, P < 0.0001), and history of growth hormone therapy (HR = 1.6; 95% CI 1.0-2.5, P = .05). Patients with a positive history of hepatitis C infection were less likely to develop HTN (HR = 0.5; 95% CI 0.3-0.9, P = .009). Prevalence of HTN was 15% overall and among survivors 11-17 years and 18-39 years old, the prevalence was 10% and 14% or triple and double that of the general U.S. population, respectively. Pediatric HCT survivors are more likely to develop HTN than the general population and should be monitored for HTN throughout adulthood.

Albuminuria in Hematopoietic Cell Transplantation Patients: Prevalence, Clinical Associations, and Impact on Survival

Chronic kidney disease (CKD) is common after hematopoietic cell transplantation (HCT). We prospectively measured the urinary albumin:creatinine ratio (ACR) in 142 patients. Total (intact) monomeric albumin was determined by liquid chromatography of untreated urine samples collected weekly to day 100 after HCT. Albuminuria was defined as ACR (mg/g creatinine) > 30; proteinuria, as ACR >300. Cox and logistic regression analyses evaluated ACR as a risk factor for clinical events. The prevalence of albuminuria was 37% at baseline, 64% at day 100, and 50% at 1 year. Proteinuria occurred in 4% of patients at baseline, in 15% at day 100, and in 4% at 1 year. Characteristics associated with albuminuria include age, sex, donor type, hypertension, and sinusoidal obstruction syndrome (SOS). Albuminuria was associated with an increased risk of acute graft-versus-host disease (aGVHD) and bacteremia, but not acute kidney injury (AKI). Albuminuria at day 100 was associated with CKD at 1 year (odds ratio = 4.0; 95% confidence interval [CI] = 1.1 to 14.6). Nonrelapse mortality (NRM) risk was elevated (hazard ratio = 6.8; 95% CI = 1.1 to 41.5) in patients with overt proteinuria at day 100. Albuminuria occurs frequently after HCT and is correlated with aGVHD, bacteremia, hypertension, and progression of renal disease. Proteinuria at day 100 is associated with an 6-fold increased risk of NRM by 1 year after HCT.

The relationship of donor source and age on short- and long-term allograft survival in pediatric renal transplantation

Abstract:  Limited pediatric data on allograft survival from advanced aged kidney donors exist. To determine the influence of donor source and age on allograft survival in pediatric renal transplant recipients, we analyzed the OPTN database. Allograft survival for 7291 pediatric renal transplants was evaluated. Up to five yr post‐transplantation, graft survival was higher for LD vs. DD recipients. At seven yr, allograft survival was 71% in 18–54 yr‐old LD recipients, 59.1% in ≥55 yr‐old LD, and 45.1% in ≥50 yr‐old DD recipients. An approximate 35% improvement in allograft survival in 18–54 yr‐old LD recipients was observed. Multivariate results showed that recipients of LD 35–49 (aRR 0.66, 95% CI 0.55–0.80) and LD 50–54 (aRR 0.65, 95% CI 0.45–0.94) have a graft survival advantage over the ideal DD. In LD ≥55 yr, no improvement in graft survival was observed when compared with the 18–34 yr‐old DD. In summary, we observed in a pediatric population, <55 yr‐old LD kidneys afford improved long‐term allograft survival when compared with DD kidney recipients. Increasing awareness of the long‐term graft survival advantage for children receiving an LD kidney, even from older donors, should be a priority.

BK nephropathy in pediatric hematopoietic stem cell transplant recipients.

Abstract:  BK nephropathy is a known cause of renal insufficiency in kidney transplant recipients. Activation of the polyoma virus may also occur in the native kidneys of non‐renal allograft recipients. BK nephropathy has only been reported in a few patients after HCT, most being adult patients, and the single reported pediatric case had evidence of hemorrhagic cystitis. The response to antiviral therapy also seems to differ widely. Here, we describe two cases of BK nephropathy in the native kidneys of HCT recipients exposed to high levels of immunosuppression because of GVHD. Neither of our patients had any evidence of hemorrhagic cystitis. We present definitive renal pathology and detailed chronological evidence of the rising serum creatinine with simultaneous serum and urine BK PCR titers. In one of our cases, antiviral therapy did not seem beneficial as documented by continued renal dysfunction and elevated serum/urine BK PCR titers. Based on our report, intense immunosuppression in pediatric HCT recipients seems to be involved in the activation of BK virus and BK nephropathy should be suspected even in the absence of hematuria in HCT recipients with unexplained renal dysfunction.

Acute Kidney Injury in Hematopoietic Cell Transplantation

Hematopoietic cell transplantation is becoming an increasingly common treatment modality for a variety of diseases. However, patient survival may be limited by substantial treatment-related toxicities, including acute kidney injury (AKI). AKI can develop in approximately 70% of patients posttransplant and is associated with an increased risk of morbidity and mortality. The development of AKI varies depending on the type of conditioning regimen used and the donor cells infused at the time of transplant, and the etiology often is multifactorial. Epidemiology, risk factors for development, pathogenesis, and potential treatment options for AKI in the hematopoietic cell transplantation population are reviewed as well as newer data on early markers of renal injury. As the indications for and number of transplants performed each year increases, nephrologists and oncologists will have to work together to identify patients who are at risk for AKI to both prevent its development and initiate therapy early to improve outcomes.