Search

Children who receive a non-renal solid organ transplant may develop secondary renal failure requiring kidney transplantation. We investigated outcomes of 165 pediatric kidney transplant recipients who previously received a heart, lung, or liver transplant using data from 1988 to 2012 reported to the United Network for Organ Sharing. Patient and allograft survival were compared with 330 matched primary kidney transplant (PKT) recipients. Kidney transplantation after solid organ transplant (KASOT) recipients experienced similar allograft survival: 5- and 10-year graft survival was 78% and 60% in KASOT recipients, compared to 80% and 61% in PKT recipients (p = 0.69). However, KASOT recipients demonstrated worse 10-year patient survival (75% KASOT vs. 97% PKT, p < 0.001). Competing risks analysis indicated that KASOT recipients more often experienced graft loss due to patient death (p < 0.001), whereas allograft failure per se was more common in PKT recipients (p = 0.01). To study more recent outcomes, kidney transplants performed from 2006 to 2012 were separately investigated. Since 2006, KASOT and PKT recipients had similar 5-year graft survival (82% KASOT vs. 83% PKT, p = 0.48), although 5-year patient survival of KASOT recipients remained inferior (90% KASOT vs. 98% PKT, p < 0.001). We conclude that despite decreased patient survival, kidney allograft outcomes in pediatric KASOT recipients are comparable to those of PKT recipients., (© 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Gene duplication has led to a most remarkable adaptation involved in vertebrates' host-pathogen arms-race, the major histocompatibility complex (MHC). However, MHC duplication history is as yet poorly understood in non-mammalian vertebrates, including birds., Results: Here, we provide evidence for the evolution of two ancient avian MHC class IIB (MHCIIB) lineages by a duplication event prior to the radiation of all extant birds >100 million years ago, and document the role of concerted evolution in eroding the footprints of the avian MHCIIB duplication history., Conclusions: Our results suggest that eroded footprints of gene duplication histories may mimic birth-death evolution and that in the avian MHC the presence of the two lineages may have been masked by elevated rates of concerted evolution in several taxa. Through the presence of a range of intermediate evolutionary stages along the homogenizing process of concerted evolution, the avian MHCIIB provides a remarkable illustration of the erosion of multigene family duplication history.

Objective: Assessment of increased glucose uptake in inflammatory or malignant myocardial disease using PET/MRI relies on uptake suppression in normal myocardium. We evaluated the efficacy of a ≥24 hours high-fat, low-carbohydrate, and protein-permitted diet (HFLCPP) in combination with unfractionated heparin for suppression of "physiologic" myocardial glucose uptake., Methods: PET/MRI was successfully performed in 89 patients. HFLCPP was started ≥24 hours prior to PET/MRI. All patients received i.v. injection of unfractionated heparin (50 IU·kg -1 ) 15 minutes prior to FDG administration. Left ventricular FDG uptake was visually evaluated by two readers. Diffuse myocardial uptake exceeding liver uptake, isolated uptake in the lateral wall, or diffuse uptake in the entire circumference of the heart base were defined as failed suppression. Homogeneous myocardial uptake below liver uptake with/without focal uptake was defined as successful suppression., Results: Success rate was 84%. Suppression was unsuccessful in 14 patients. No significant influence of gender (P = .40) or age (P = .21) was found. However, insufficient suppression was more common in patients younger than 45 years (20% vs 7%). PET/MR imaging completion rate was >97%., Conclusion: A HFLCPP diet in combination with unfractionated heparin was successfully implemented for cardiac PET/MRI and resulted in a sufficient suppression of myocardial FDG uptake in 84% of patients.

The serotonin transporter (SERT) mediates Na + -dependent high-affinity serotonin uptake and plays a key role in regulating extracellular serotonin concentration in the brain and periphery. To gain novel insight into SERT regulation, we conducted a comprehensive proteomics screen to identify components of SERT-associated protein complexes in the brain by employing three independent approaches. In vivo SERT complexes were purified from rat brain using an immobilized high-affinity SERT ligand, amino-methyl citalopram. This approach was combined with GST pulldown and yeast two-hybrid screens using N- and C-terminal cytoplasmic transporter domains as bait. Potential SERT associated proteins detected by at least two of the interaction methods were subjected to gene ontology analysis resulting in the identification of functional protein clusters that are enriched in SERT complexes. Prominent clusters include synaptic vesicle proteins, as well as proteins involved in energy metabolism and ion homeostasis. Using subcellular fractionation and electron microscopy we provide further evidence that SERT is indeed associated with synaptic vesicle fractions, and colocalizes with small vesicular structures in axons and axon terminals. We also show that SERT is found in close proximity to mitochondrial membranes in both, hippocampal and neocortical regions. We propose a model of the SERT interactome, in which SERT is distributed between different subcellular compartments through dynamic interactions with site-specific protein complexes. Finally, our protein interaction data suggest novel hypotheses for the regulation of SERT activity and trafficking, which ultimately impact on serotonergic neurotransmission and serotonin dependent brain functions.

Objectives: Improved real-time cardiac magnetic resonance (CMR) sequences have currently been introduced, but so far only limited practical experience exists. This study aimed at image reconstruction optimization and clinical validation of a new highly accelerated real-time cine SPARSE-SENSE sequence., Methods: Left ventricular (LV) short-axis stacks of a real-time free-breathing SPARSE-SENSE sequence with high spatiotemporal resolution and of a standard segmented cine SSFP sequence were acquired at 1.5 T in 11 volunteers and 15 patients. To determine the optimal iterations, all volunteers' SPARSE-SENSE images were reconstructed using 10-200 iterations, and contrast ratios, image entropies, and reconstruction times were assessed. Subsequently, the patients' SPARSE-SENSE images were reconstructed with the clinically optimal iterations. LV volumetric values were evaluated and compared between both sequences., Results: Sufficient image quality and acceptable reconstruction times were achieved when using 80 iterations. Bland-Altman plots and Passing-Bablok regression showed good agreement for all volumetric parameters., Conclusions: 80 iterations are recommended for iterative SPARSE-SENSE image reconstruction in clinical routine. Real-time cine SPARSE-SENSE yielded comparable volumetric results as the current standard SSFP sequence. Due to its intrinsic low image acquisition times, real-time cine SPARSE-SENSE imaging with iterative image reconstruction seems to be an attractive alternative for LV function analysis., Key Points: • A highly accelerated real-time CMR sequence using SPARSE-SENSE was evaluated. • SPARSE-SENSE allows free breathing in real-time cardiac cine imaging. • For clinically optimal SPARSE-SENSE image reconstruction, 80 iterations are recommended. • Real-time SPARSE-SENSE imaging yielded comparable volumetric results as the reference SSFP sequence. • The fast SPARSE-SENSE sequence is an attractive alternative to standard SSFP sequences.

Introduction: The objective of this study was to assess the diagnostic value of integrated 11C- methionine PET/MRI for suspected primary brain tumors, in comparison to MRI alone., Material and Methods: Forty-eight consecutive patients with suspected primary brain tumor were prospectively enrolled for an integrated 11C-methionine PET/MRI. Two neuro-radiologists separately evaluated the MRI alone and the integrated PET/MRI data sets regarding most likely diagnosis and diagnostic confidence on a 5-point scale. Reference standard was histopathology or follow-up imaging., Results: Fifty-one suspicious lesions were detected: 16 high-grade glioma and 25 low-grade glioma. Ten non-malignant cerebral lesions were described by the reference standard. MRI alone and integrated PET/MRI each correctly classified 42 of the 51 lesions (82.4%) as neoplastic lesions (WHO grade II, III and IV) or non-malignant lesions (infectious and neoplastic lesions). Diagnostic confidence for all lesions, low-grade astrocytoma and high-grade astrocytoma (3.7 vs. 4.2, 3,1 vs. 3.8, 4.0 vs. 4,7) were significantly (p < 0.05) better with integrated PET/MRI than in MRI alone., Conclusions: The present study demonstrates the high potential of integrated 11C-methionine-PET/MRI for the assessment of suspected primary brain tumors. Although integrated methionine PET/MRI does not lead to an improvement of correct diagnoses, diagnostic confidence is significantly improved., Competing Interests: The authors have declared that no competing interests exist.

Determination of concentration-time profiles in cynomolgus monkeys of a therapeutic monoclonal antibody against a soluble target revealed a substantial discrepancy between a generic anti-human IgG capture/detection and target bridging assay with the target bridging assay leading to dose- and time-dependent underquantification of drug concentrations, lack of parallelism and subsequently different pharmacokinetic parameters. In contrast, plasma levels derived from a target capture and an anti-idiotypic antibody bridging assay were in close concordance with the generic assay and demonstrated parallelism with high precision across several dilutions. The results provide a practical attempt to overcome nonparallelism by employing alternative assay formats utilizing tailored assay reagent combinations in order to obtain unbiased pharmacokinetic data.

Background: Patients with diabetes and cancer have higher mortality and morbidity rates, and are more likely to be hospitalized during treatment. In addition, they often prioritize cancer treatment over self-management of diabetes., Objectives: This research aims to identify the issues regarding the management of diabetes in patients with cancer by examining the perspectives of oncology providers, nurses, and patients., Methods: This study used six focus groups of oncology providers, nurses, and patients with preexisting diabetes who received chemotherapy for a solid tumor or lymphoma. Participants were recruited from two outpatient cancer centers in Michigan. All focus group discussions were audio recorded and transcribed, and thematic analysis was conducted to identify common themes., Findings: Three overarching themes were identified by patients, nurses, and oncologists.

Objectives: To investigate the influence of intravenous gadolinium on cartilage T2 and T2* relaxation times and on morphological image quality at 7-T hip MRI., Methods: Hips of 11 healthy volunteers were examined at 7 T. Multi-echo sequences for T2 and T2* mapping, 3D T1 volumetric interpolated breath-hold examination (VIBE) and double-echo steady-state (DESS) sequences were acquired before and after intravenous application of gadolinium according to a delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) protocol. Cartilage relaxation times were measured in both scans. Morphological sequences were assessed quantitatively using contrast ratios and qualitatively using a 4-point Likert scale. Student's t-test, Pearson's correlation (ρ) and Wilcoxon sign-rank test were used for statistical comparisons., Results: Pre- and post-contrast T2 and T2* values were highly correlated (T2: acetabular: ρ = 0.76, femoral: ρ = 0.77; T2*: acetabular: ρ = 0.80, femoral: ρ = 0.72). Gadolinium enhanced contrasts between cartilage and joint fluid in DESS and T1 VIBE according to the qualitative (p = 0.01) and quantitative (p < 0.001) analysis. The delineation of acetabular and femoral cartilage and the labrum predominantly improved with gadolinium., Conclusions: Gadolinium showed no relevant influence on T2 or T2* relaxation times and improved morphological image quality at 7 T. Therefore, morphological and quantitative sequences including dGEMRIC can be conducted in a one-stop-shop examination., Key Points: • Hip cartilage T2 values correlate highly before and after gadolinium at 7 T • Hip cartilage T2* values correlate highly before and after enhancement at 7 T • Morphological hip cartilage imaging benefits from intravenous gadolinium at 7 T • The delineation of acetabular and femoral cartilage can be improved by gadolinium • Morphological and quantitative sequences including dGEMRIC can be combined as a one-stop-shop examination.

Background: After hematopoietic cell transplantation (HCT), polyoma-BK virus is associated with hemorrhagic cystitis and also with polyomavirus nephropathy (PVN). However, the true burden of post-HCT PVN is unknown because kidney biopsies are avoided due to their bleeding risk. The novel, noninvasive urinary PV-Haufen test detects PVN in kidney transplant recipients with greater than 95% positive/negative predictive values. We hypothesized that the detection of PV-Haufen in voided urine samples-a positive PV-Haufen test-was also clinically significant after HCT., Methods: We examined 21 suitable urine samples from 14 patients (median age, 15 years; 71.4% male) who were selected from repositories for having varying degrees of BK viremia (range, 0-1.0 × 10 copies/mL), hemorrhagic cystitis (present/absent), and data on kidney function. Urine samples were obtained at a median of 88 days post-HCT., Results: The PV-Haufen were detected in 5 of 14 patients (35.7%) and 7 of 21 (33.3%) urine samples, with histologic confirmation of PVN in 1 autopsy specimen. After a median of 285 days post-HCT, patients with PV-Haufen had an increased risk of dialysis-dependent renal failure (P < 0.05). All 3 dialysis-dependent patients had PV-Haufen and died. The presence of urinary PV-Haufen was not significantly correlated with hemorrhagic cystitis. From the 16 urines collected during BK viremia, 43.8% were PV-Haufen-positive, and 56.2% were negative. The PV-Haufen were not present in the 5 urines from patients without concomitant BK-viremia., Conclusions: In this proof-of-concept study, a positive PV-Haufen test was only seen in some patients with BK viremia and was not associated with hemorrhagic cystitis. The detection of PV-Haufen suggests underlying PVN with an increased risk of kidney failure and dialysis.

Background: Glioblastomas (GBM) are the most common malignant type of primary brain tumor. GBM are intensively treated with surgery and combined radiochemotherapy using X-irradiation and temozolomide (TMZ) but they are still associated with an extremely poor prognosis, urging for the development of new treatment strategies. To improve the outcome of GBM patients, the small molecule multi-kinase inhibitor sorafenib has moved into focus of recent research. Sorafenib has already been shown to enhance the radio- and radiochemosensitivity of other tumor entities. Whether sorafenib is also able to sensitize GBM cells to radio- and chemotherapy is still an unsolved question which we have addressed in this study., Methods: The effect of sorafenib on signaling, proliferation, radiosensitivity, chemosensitivity and radiochemosensitivity was analyzed in six glioblastoma cell lines using Western blot, proliferation- and colony formation assays., Results: In half of the cell lines sorafenib clearly inhibited MAPK signaling. We also observed a strong blockage of proliferation, which was, however, not associated with MAPK pathway inhibition. Sorafenib had only minor effects on cell survival when administered alone. Most importantly, sorafenib treatment failed to enhance GBM cell killing by irradiation, TMZ or combined treatment, and instead rather caused resistance in some cell lines., Conclusion: Our data suggest that sorafenib treatment may not improve the efficacy of radiochemotherapy in GBM., Competing Interests: All authors declare no conflict of interest.

Purpose: To assess two compressed sensing cine magnetic resonance imaging (MRI) sequences with high spatial or high temporal resolution in comparison to a reference steady-state free precession cine (SSFP) sequence for reliable quantification of left ventricular (LV) volumes., Materials and Methods: LV short axis stacks of two compressed sensing breath-hold cine sequences with high spatial resolution (SPARSE-SENSE HS: temporal resolution: 40 msec, in-plane resolution: 1.0 × 1.0 mm(2) ) and high temporal resolution (SPARSE-SENSE HT: temporal resolution: 11 msec, in-plane resolution: 1.7 × 1.7 mm(2) ) and of a reference cine SSFP sequence (standard SSFP: temporal resolution: 40 msec, in-plane resolution: 1.7 × 1.7 mm(2) ) were acquired in 16 healthy volunteers on a 1.5T MR system. LV parameters were analyzed semiautomatically twice by one reader and once by a second reader. The volumetric agreement between sequences was analyzed using paired t-test, Bland-Altman plots, and Passing-Bablock regression., Results: Small differences were observed between standard SSFP and SPARSE-SENSE HS for stroke volume (SV; -7 ± 11 ml; P = 0.024), ejection fraction (EF; -2 ± 3%; P = 0.019), and myocardial mass (9 ± 9 g; P = 0.001), but not for end-diastolic volume (EDV; P = 0.079) and end-systolic volume (ESV; P = 0.266). No significant differences were observed between standard SSFP and SPARSE-SENSE HT regarding EDV (P = 0.956), SV (P = 0.088), and EF (P = 0.103), but for ESV (3 ± 5 ml; P = 0.039) and myocardial mass (8 ± 10 ml; P = 0.007). Bland-Altman analysis showed good agreement between the sequences (maximum bias ≤ -8%)., Conclusion: Two compressed sensing cine sequences, one with high spatial resolution and one with high temporal resolution, showed good agreement with standard SSFP for LV volume assessment. J. Magn. Reson. Imaging 2016;44:366-374., (© 2016 Wiley Periodicals, Inc.)

Objectives: T1 mapping allows quantitative myocardial assessment, but its value in clinical routine remains unclear. We investigated, whether the average native myocardial T1 value can be used as a diagnostic classifier between healthy and diffuse diseased myocardium., Methods: Native T1 mapping was performed in 54 persons with healthy hearts and in 150 patients with diffuse myocardial pathologies (coronary artery disease (CAD): n = 76, acute myocarditis: n = 19, convalescent myocarditis: n = 26, hypertrophic cardiomyopathy (HCM): n = 12, dilated cardiomyopathy (DCM): n = 17) at 1.5 Tesla in a mid-ventricular short axis slice using a modified Look-Locker inversion recovery (MOLLI) sequence. The average native myocardial T1 value was measured using dedicated software for each patient. The mean as well as the range of the observed average T1 values were calculated for each group, and compared using t-test. The ability of T1 mapping to differentiate between healthy and diffuse diseased myocardium was assessed using receiver operating characteristic analysis (ROC)., Results: The mean T1 value of the group "healthy hearts" (955±34ms) differed significantly from that of the groups DCM (992±37ms, p<0.001), HCM (980±44ms, p = 0.035), and acute myocarditis (974±36ms, p = 0.044). No significant difference was observed between the groups "healthy hearts" and CAD (951±37ms, p = 0.453) or convalescent myocarditis (965±40ms, p = 0.240). The average native T1 value varied considerably within all groups (range: healthy hearts, 838-1018ms; DCM, 882-1034ms; HCM, 897-1043ms; acute myocarditis, 925-1025ms; CAD, 867-1082ms; convalescent myocarditis, 890-1071ms) and overlapped broadly between all groups. ROC analysis showed, that the average native T1 value does not allow for differentiating between healthy and diffuse diseased myocardium, except for the subgroup of DCM., Conclusions: The average native T1 value in cardiac MR imaging does not allow differentiating between healthy and diffusely diseased myocardium in individual cases.

Thrombotic microangiopathy (TMA) after hematopoietic stem cell transplantation (HSCT) associated with terminal complement activation, as measured by elevated plasma terminal complement (sC5b-9) concentrations, has a very high mortality. The complement inhibitor eculizumab may be a therapeutic option for HSCT-associated TMA. We examined the pharmacokinetics and pharmacodynamics (PK/PD) of eculizumab in children and young adult HSCT recipients with TMA and activated complement to determine drug dosing requirements for future efficacy trials. We analyzed prospectively collected laboratory samples and clinical data from 18 HSCT recipients with high-risk TMA presenting with complement activation who were treated with eculizumab. We measured eculizumab serum concentrations, total hemolytic complement activity, and plasma sC5b-9 concentrations. Population PK/PD analyses correlated eculizumab concentrations with complement blockade and clinical response and determined interindividual differences in PK parameters. We also compared transplant survival in patients treated with eculizumab (n = 18) with patients with the same high-risk TMA features who did not receive any targeted therapy during a separate prospective observational study (n = 11). In the PK analysis, we found significant interpatient variability in eculizumab clearance, ranging from 16 to 237 mL/hr/70 kg in the induction phase. The degree of complement activation measured by sC5b-9 concentrations at the start of therapy, in addition to actual body weight, was a significant determinant of eculizumab clearance and disease response. Sixty-one percent of treated patients had complete resolution of TMA and were able to safely discontinue eculizumab without disease recurrence. Overall survival was significantly higher in treated subjects compared with untreated patients (56% versus 9%, P = .003). Complement blocking therapy is associated with improved survival in HSCT patients with high-risk TMA who historically have dismal outcomes, but eculizumab pharmacokinetics in HSCT recipients differ significantly from reports in other diseases like atypical hemolytic uremic syndrome and paroxysmal nocturnal hemoglobinuria. Our eculizumab dosing algorithm, including pr-treatment plasma sC5b-9 concentrations, patient's actual body weight, and the first eculizumab dose (mg), accurately determined eculizumab concentration-time profiles for HSCT recipients with high-risk TMA. This algorithm may guide eculizumab treatment and ensure that future efficacy studies use the most clinically appropriate and cost-efficient dosing schedules., (Copyright © 2016 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Previous studies suggest that quantifying donor-reactive memory T cells prior to kidney transplantation by interferon gamma enzyme-linked immunosorbent spot assay (IFNγELISPOT) can assist in assessing risk of posttransplant allograft injury. Herein, we report an analysis of IFNγELISPOT results from the multicenter, Clinical Trials in Organ Transplantation-01 observational study of primary kidney transplant recipients treated with heterogeneous immunosuppression. Within the subset of 176 subjects with available IFNγELISPOT results, pretransplant IFNγELISPOT positivity surprisingly did not correlate with either the incidence of acute rejection (AR) or estimated glomerular filtration rate (eGFR) at 6- or 12-month. These unanticipated results prompted us to examine potential effect modifiers, including the use of T cell-depleting, rabbit anti-thymocyte globulin (ATG). Within the no-ATG subset, IFNγELISPOT(neg) subjects had higher 6- and 12-month eGFRs than IFNγELISPOT(pos) subjects, independent of biopsy-proven AR, peak PRA, human leukocyte antigen mismatches, African-American race, donor source, and recipient age or gender. In contrast, IFNγELISPOT status did not correlate with posttransplant eGFR in subjects given ATG. Our data confirm an association between pretransplant IFNγELISPOT positivity and lower posttransplant eGFR, but only in patients who do not receive ATG induction. Controlled studies are needed to test the hypothesis that ATG induction is preferentially beneficial to transplant candidates with high frequencies of donor-reactive memory T cells., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Post-transplant seizures are uncommon in young kidney transplant recipients but can be harbingers of devastating outcomes such as cerebral edema and death. We reviewed all transplants performed at our institution from January 2013 to January 2014 and compared three patients who seized within 24 h post-transplant (cases) with the remaining 33 transplant recipients (controls). Records were reviewed for hyponatremia, hypocalcemia, hypomagnesemia, BUN clearance, osmolality shifts, and blood pressure control in the first 24 h post-transplant. All cases had more pronounced (p < 0.001) shifts in serum sodium and calculated serum osmolality, with their sodium decreasing by >15 mmol/L to nadir values of 124, 131, and 131 mmol/L, respectively. There were no differences in serum calcium corrected for hypoalbuminemia, serum magnesium, urine output, or blood pressure control between the groups. Our study suggests that mild hyponatremia and an acute decrease in serum osmolality are risk factors for potentially severe postoperative neurologic complications following kidney transplantation. Thus, peri-transplant management should be optimized to anticipate and prevent these abnormalities., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

BK virus (BKV) is associated with kidney and bladder disease after hematopoietic cell transplantation (HCT) but less is known about the seroprevalence of pre-transplant antibodies to BKV in children. We measured BKV IgG antibody titers in 36 children before HCT. BKV IgG antibodies were detected in all 36 patients, with 28/36 (77.8%) developing BK viremia in the first 100 days. Pre-HCT BKV IgG antibody titers >1:40,960 were protective against later BK viremia ≥10,000 copies/ml. The seroprevalence of antibodies to BKV is high in children undergoing HCT and post-transplant BK viremia, which is associated with bladder and kidney injury, is common., (© 2015 Wiley Periodicals, Inc.)

Background: The Patient Reported Outcomes Measurement Information System (PROMIS) II is a prospective study that evaluates patient reported outcomes in pediatric chronic diseases as a measure of health-related quality of life (HRQOL). We have evaluated the influence of disease duration on HRQOL and, for the first time, compared the findings of the PROMIS measures to those of the PedsQL™ 4.0 Generic Scales (PedsQL) from the PROMIS II nephrotic syndrome (NS) longitudinal cohort., Methods: This was a prospective study in which 127 children (age range 8-17 years) with active NS from 14 centers were enrolled. Children with active NS defined as the presence of nephrotic range proteinuria (>2+ urinalysis and edema or urine protein/creatinine ratio >2 g/g) were eligible. Comparisons were made between children with prevalent (N = 67) and incident (N = 60) disease at the study enrollment visit., Results: The PROMIS scores were worse in prevalent patients in the domains of peer relationship (p = 0.01) and pain interference (p < 0.01). The PedsQL showed worse scores in prevalent patients for social functioning (p < 0.01) and school functioning (p = 0.03). Multivariable analyses showed that prevalent patients had worse scores in PROMIS pain interference (p = 0.02) and PedsQL social functioning (p < 0.01)., Conclusion: The PROMIS measures detected a significant impact of disease duration on HRQOL in children, such that peer relationships were worse and pain interfered with daily life to a greater degree among those with longer disease duration. These findings were in agreement with those for similar domains in the PedsQL legacy instrument.

Background/purpose: Mortality from end stage renal disease (ESRD) in patients with anorectal malformation (ARM) is reported to be between 2.5 and 6%. The risk differs depending on the type of ARM (6.4% "high" vs. 1.1% "low"). The purpose of this study was to review the characteristics of the ARM patients who received a kidney transplant (KT) to potentially identify if any modifiable factors existed that may have prevented ESRD., Methods: The Colorectal Center and the kidney transplant databases at Cincinnati Children's Hospital were queried to identify patients with ARM and a KT. Data obtained included: gender, type of ARM, associated characteristics, urological status at birth, surgical and medical management, age at KT, and possible interventions that could have prevented or delayed the KT., Results: 20 patients with ARM who underwent KT were identified. 16 were females, thirteen of whom had a cloaca; the average common channel length in these patients was 5 cm, ranging from 2 to 8 cm. Nine cloaca patients had hydrocolpos and 5 of them were not drained at birth. Eleven patients presented with renal failure at birth. Five patients with cloaca had common channel atresia/stenosis, 2 male patients had severe urethral atresia, 2 patients had absent bladders, and 1 patient had bilateral blind ureters. At birth, 6 patients had single functional kidneys, 4 had bilateral hydronephrosis with megaureters, 3 patients had bilateral dysplastic kidneys, 1 patient had a single kidney with hydronephrosis, and 1 patient had a single hypoplastic kidney. The average age at KT was 10.9 years (range 2-21 years.); in 3 patients, the KT was performed before the repair of the ARM. One patient died after the KT and one patient had rejection following the KT and is currently on hemodialysis., Conclusion: Patients with cloaca and recto-bladderneck fistula are the type of ARM with the highest risk for ESRD. Kidney failure at birth, common channel/urethral atresia, hydrocolpos, single kidney, and ectopic ureters represent high risk for future KT. Even when missed opportunities were identified, the impact of interventions to prevent or delay the onset of ESRD could not be proven.

Hypertension in pediatric kidney transplant recipients contributes to long-term graft loss, yet treatment options--including angiotensin-converting enzyme inhibitors--are poorly characterized in this vulnerable population. We conducted a multicenter, open-label pharmacokinetic (PK) study of daily oral lisinopril in 22 children (ages 7-17 years) with stable kidney transplant function. Standard noncompartmental PK analyses were performed at steady state. Effects on blood pressure were examined in lisinopril-naïve patients (n = 13). Oral clearance declined in proportion to underlying kidney function; however, in patients with low estimated glomerular filtration rate (30-59 ml/min per 1.73m(2)), exposure (standardized to 0.1 mg/kg/day dose) was within the range reported previously in children without a kidney transplant. In lisinopril-naïve patients, 85% and 77% had a ≥ 6 mmHg reduction in systolic and diastolic blood pressure, respectively. Lisinopril was well tolerated. Our study provides initial insight on lisinopril use in children with a kidney transplant, including starting dose considerations., (© 2015 American Society for Clinical Pharmacology and Therapeutics.)

Background: Cardiovascular disease is the leading cause of death in children with end-stage renal disease (ESRD). Isolated aortic dilation (AD) is rare in children. We aimed to determine the prevalence and the risk factors for AD in children with ESRD., Methods and Study Design: We reviewed records of all ESRD patients followed mat our institution from January 2007 to October 2012. AD was defined as Z-score > 2 in the dimension of at least one of the following echocardiographic aortic parameters: annulus, root at the sinus, sino-tubular junction, or ascending aorta., Results: The records of 78 patients on dialysis and 19 kidney transplant recipients were available. 30 patients (30.9%) had AD. Multivariate analysis revealed independent associations of AD with body mass index (BMI) Z-score (OR = 0.52, 95% confidence interval (CI): 0.35 - 0.78) and ESRD secondary to glomerular disease (OR = 4.58, 95% CI: 1.45 - 14.46). We developed a classification and regression tree (CART) model to identify patients at low vs. high AD risk. Our model classified 62 patients of the cohort (64%) to be high- or lowrisk, with a positive predictive value of 89% and a negative predictive value of 100%., Conclusion: Our data suggest that AD, as a possible marker of aortopathy and early aneurysm formation, is a novel and prevalent cardiovascular complication in ESRD children. Glomerular disease and low BMI Zscore appear to be potent predictors. CART modeling helps identify high-risk children, potentially guiding decisions regarding targeted echocardiographic evaluations.

Hematopoietic stem cell transplantation (HSCT)-associated thrombotic microangiopathy (TA-TMA) is now a well-recognized and potentially severe complication of HSCT that carries a high risk of death. In those who survive, TA-TMA may be associated with long-term morbidity and chronic organ injury. Recently, there have been new insights into the incidence, pathophysiology, and management of TA-TMA. Specifically, TA-TMA can manifest as a multi-system disease occurring after various triggers of small vessel endothelial injury, leading to subsequent tissue damage in different organs. While the kidney is most commonly affected, TA-TMA involving organs such as the lung, bowel, heart, and brain is now known to have specific clinical presentations. We now review the most up-to-date research on TA-TMA, focusing on the pathogenesis of endothelial injury, the diagnosis of TA-TMA affecting the kidney and other organs, and new clinical approaches to the management of this complication after HSCT., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: Mycophenolic acid (MPA) is a key immunosuppressive drug that acts through inhibition of inosine monophosphate dehydrogenase (IMPDH). MPA is commonly measured, as part of therapeutic drug monitoring, as the total concentration in plasma. However, it has been postulated that the free (unbound) fraction of MPA (fMPA) is responsible for the immunosuppressive effects. In this study, a sensitive low volume high-performance liquid chromatography (HPLC) assay was developed to measure fMPA concentrations to explore the relationship between fMPA and IMPDH activity., Methods: To obtain fMPA concentrations, plasma samples were filtrated using Centrifree ultrafiltration devices. The ultrafiltrate was analyzed by HPLC using a Kinetex C18 column (2.6 μm, 3.0 × 75 mm). fMPA concentrations were compared with the total MPA concentrations available in 28 pediatric kidney transplant patients at 3 consecutive occasions after transplantation. The relationship between fMPA and IMPDH activity was analyzed using an Emax model., Results: The HPLC assay, using 25 μL of the ultrafiltrates, was validated over a range from 2.5 to 1000 μL with good accuracy, precision, and reproducibility. Total and free MPA concentrations were well correlated (R = 0.85, P < 0.0001), although large intraindividual and interindividual variability in the bound MPA fractions was observed. The overall relationship between fMPA concentrations and IMPDH inhibition using the Emax model was comparable with that of total MPA, as previously reported. The model estimated EC50 value (164.5 μL) is in good agreement with reported in vitro EC50 values., Conclusions: This study provides a simple HPLC method for the measurement of fMPA and a pharmacologically reasonable EC50 estimate. The good correlation between the total and free MPA concentrations suggests that routine measurement of fMPA to characterize mycophenolate pharmacokinetic and pharmacodynamic does not seem warranted, although the large variability in the bound fractions of MPA warrants further study.

The focus of the present study was to characterize the phosphoproteome of cytotoxic T cells and to explore the role of the serine threonine kinase PKD2 (Protein Kinase D2) in the phosphorylation networks of this key lymphocyte population. We used Stable Isotope Labeling of Amino acids in Culture (SILAC) combined with phosphopeptide enrichment and quantitative mass-spectrometry to determine the impact of PKD2 loss on the cytotoxic T cells phosphoproteome. We identified 15,871 phosphorylations on 3505 proteins in cytotoxic T cells. 450 phosphosites on 281 proteins were down-regulated and 300 phosphosites on 196 proteins were up-regulated in PKD2 null cytotoxic T cells. These data give valuable new insights about the protein phosphorylation networks operational in effector T cells and reveal that PKD2 regulates directly and indirectly about 5% of the cytotoxic T-cell phosphoproteome. PKD2 candidate substrates identified in this study include proteins involved in two distinct biological functions: regulation of protein sorting and intracellular vesicle trafficking, and control of chromatin structure, transcription, and translation. In other cell types, PKD substrates include class II histone deacetylases such as HDAC7 and actin regulatory proteins such as Slingshot. The current data show these are not PKD substrates in primary T cells revealing that the functional role of PKD isoforms is different in different cell lineages., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)

Background and Objectives: Chronic kidney disease is a persistent chronic health condition commonly seen in pediatric nephrology programs. Our study aims to evaluate the sensitivity of the Patient Reported Outcomes Measurement Information System (PROMIS) pediatric instrument to indicators of disease severity and activity in pediatric chronic kidney disease., Methods: This cross sectional study included 233 children 8-17 years old, with chronic kidney disease from 16 participating institutions in North America. Disease activity indicators, including hospitalization in the previous 6 months, edema, and number of medications consumed daily, as well as disease severity indicators of kidney function and coexisting medical conditions were captured. PROMIS domains, including depression, anxiety, social-peer relationships, pain interference, fatigue, mobility, and upper extremity function, were administered via web-based questionnaires. Absolute effect sizes (AES) were generated to demonstrate the impact of disease on domain scores. Four children were excluded because of missing glomerular filtration rate (GFR) estimations., Results: Of the 229 children included in the final analysis, 221 completed the entire PROMIS questionnaire. Unadjusted PROMIS domains were responsive to chronic kidney disease activity indicators and number of coexisting conditions. PROMIS domain scores were worse in the presence of recent hospitalizations (depression AES 0.33, anxiety AES 0.42, pain interference AES 0.46, fatigue AES 0.50, mobility AES 0.49), edema (depression AES 0.50, anxiety AES 0.60, pain interference AES 0.77, mobility AES 0.54) and coexisting medical conditions (social peer-relationships AES 0.66, fatigue AES 0.83, mobility AES 0.60, upper extremity function AES 0.48)., Conclusions: The PROMIS pediatric domains of depression, anxiety, social-peer relationships, pain interference, and mobility were sensitive to the clinical status of children with chronic kidney disease in this multi-center cross sectional study. We demonstrated that a number of important clinical characteristics including recent history of hospitalization and edema, affected patient perceptions of depression, anxiety, pain interference, fatigue and mobility. The PROMIS instruments provide a potentially valuable tool to study the impact of chronic kidney disease. Additional studies will be required to assess responsiveness in PROMIS score with changes in disease status over time.

An accurate assessment of kidney function before hematopoietic cell transplantation (HCT) can help to properly dose conditioning chemotherapy and follow patients for the development of chronic kidney disease. We cross-sectionally examined 94 children and young adults before HCT to compare formal nuclear glomerular filtration rate (GFR) testing with estimated GFR using creatinine and cystatin C-based equations, including the original Schwartz formula and the more recent formulas developed in the Chronic Kidney Disease in Children (CKiD) cohort. The median age of the cohort was 5.9 years (range, .26 to 30.5 years). The mean cohort nuclear GFR was 107.4 ± 24.7 mL/min/1.73 m(2), with 18 of 94 subjects (19.1%) having abnormal kidney function (GFR < 90 mL/min/1.73 m(2)) before HCT. The creatinine-based original Schwartz and bedside CKiD formulas showed significant bias, overestimating the nuclear GFR by 57.4 (95% confidence interval [CI], 49.0 to 65.8) and 14.1 (95% CI, 7.1 to 21.1) mL/min/1.73 m(2), respectively. Cystatin C formulas had less mean bias and improved accuracy but also had decreased sensitivity to detect abnormal kidney function before HCT. The Full CKiD equation showed the best performance, with a mean bias of -3.6 mL/min/1.73 m(2) (95% CI, -8.4 to 1.2) that was not significantly different from the measured value and 87.7% of estimates within ±30% of the nuclear GFR. Although the more recent bedside CKiD formula performed better than the original Schwartz formula, both formulas had poor sensitivity for detecting a low GFR. An abnormal pretransplant nuclear GFR was not associated with post-HCT acute kidney injury, the need for dialysis, or death in the first 100 days. In conclusion, we observed cystatin C-based equations outperformed creatinine-based equations in estimating GFR in children before HCT. However, all formulas had decreased sensitivity to detect impaired GFR. Formal measurement of kidney function should be considered in children and young adults who need an accurate assessment of kidney function before HCT., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Aim: The purpose of this study was to develop a population pharmacokinetic and pharmacodynamic (PK-PD) model for mycophenolic acid (MPA) in paediatric renal transplant recipients in the early post-transplant period., Methods: A total of 214 MPA plasma concentrations-time data points from 24 patients were available for PK model development. In 17 out of a total of 24 patients, inosine monophosphate dehydrogenase (IMPDH) enzyme activity measurements (n = 97) in peripheral blood mononuclear cells were available for PK-PD modelling. The PK-PD model was developed using non-linear mixed effects modelling sequentially by 1) developing a population PK model and 2) incorporating IMPDH activity into a PK-PD model using post hoc Bayesian PK parameter estimates. Covariate analysis included patient demographics, co-medication and clinical laboratory data. Non-parametric bootstrapping and prediction-corrected visual predictive checks were performed to evaluate the final models., Results: A two compartment model with a transit compartment absorption best described MPA PK. A non-linear relationship between dose and MPA exposure was observed and was described by a power function in the model. The final population PK parameter estimates (and their 95% confidence intervals) were CL/F, 22 (14.8, 25.2) l h(-1) 70 kg(-1) ; Vc /F, 45.4 (29.6, 55.6) l; Vp /F, 411 (152.6, 1472.6)l; Q/F, 22.4 (16.0, 32.5) l h(-1) ; Ka , 2.5 (1.45, 4.93) h(-1) . Covariate analysis in the PK study identified body weight to be significantly correlated with CL/F. A simplified inhibitory Emax model adequately described the relationship between MPA concentration and IMPDH activity. The final population PK-PD parameter estimates (and their 95% confidence intervals) were: E0 , 3.45 (2.61, 4.56) nmol h(-1)  mg(-1) protein and EC50 , 1.73 (1.16, 3.01) mg l(-1) . Emax was fixed to 0. There were two African-American patients in our study cohorts and both had low IMPDH baseline activities (E0 ) compared with Caucasian patients (mean value 2.13 mg l(-1) vs. 3.86 mg l(-1) )., Conclusion: An integrated population PK-PD model of MPA has been developed in paediatric renal transplant recipients. The current model provides information that will facilitate future studies and may be implemented in a Bayesian algorithm to allow a PK-PD guided therapeutic drug monitoring strategy., (© 2014 The British Pharmacological Society.)

Transplant-associated thrombotic microangiopathy (TMA) leads to generalized endothelial dysfunction that can progress to multiorgan injury, and severe cases are associated with poor outcomes after hematopoietic stem cell transplantation (HSCT). Identifying patients at highest risk for severe disease is challenging. We prospectively evaluated 100 consecutive HSCT recipients to determine the incidence of moderate and severe TMA and factors associated with poor overall outcomes. Thirty-nine subjects (39%) met previously published criteria for TMA. Subjects with TMA had a significantly higher nonrelapse mortality (43.6% vs 7.8%, P < .0001) at 1 year post-HSCT compared with those without TMA. Elevated lactate dehydrogenase, proteinuria on routine urinalysis, and hypertension were the earliest markers of TMA. Proteinuria (>30 mg/dL) and evidence of terminal complement activation (elevated sC5b-9) in the blood at the time of TMA diagnosis were associated with very poor survival (<20% at 1 year), whereas all TMA subjects without proteinuria and a normal sC5b-9 serum concentration survived (P < .01). Based on these prospective observations, we conclude that severe TMA occurred in 18% of HSCT recipients in our cohort and propose an algorithm to identify the highest-risk patients who might benefit from prompt clinical interventions., (© 2014 by The American Society of Hematology.)

Standard treatments for AMR-rituximab, intravenous immunoglobulin, and/or plasmapheresis-aim to suppress the production and modulate the effect of donor-specific antibodies and remove them, respectively. Proteasome inhibitors such as bortezomib are potent therapeutic agents that target plasma cells more effectively than rituximab to reduce measurable donor-specific antibody production. Little is known in adults, and no data exist in children about effects of proteasome inhibition to treat AMR on protective antibody titers. We present a pediatric renal transplant recipient who received bortezomib for relatively early AMR and whose antibody titers to measles and tetanus were tracked. The AMR was treated successfully, and we noted no clinical decrease in the overall level of protective immunity from pretransplant baseline levels at almost one yr after AMR treatment cessation. Larger studies will elucidate more clearly how proteasome inhibition to treat AMR affects protective immunity in pediatric transplant recipients., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

We recently observed that dysregulation of the complement system may be involved in the pathogenesis of hematopoietic stem cell transplantation-associated thrombotic microangiopathy (HSCT-TMA). These findings suggest that the complement inhibitor eculizumab could be a therapeutic option for this severe HSCT complication with high mortality. However, the efficacy of eculizumab in children with HSCT-TMA and its dosing requirements are not known. We treated 6 children with severe HSCT-TMA using eculizumab and adjusted the dose to achieve a therapeutic level >99 μg/mL. HSCT-TMA resolved over time in 4 of 6 children after achieving therapeutic eculizumab levels and complete complement blockade, as measured by low total hemolytic complement activity (CH50). To achieve therapeutic drug levels and a clinical response, children with HSCT-TMA required higher doses or more frequent eculizumab infusions than currently recommended for children with atypical hemolytic uremic syndrome. Two critically ill patients failed to reach therapeutic eculizumab levels, even after dose escalation, and subsequently died. Our data indicate that eculizumab may be a therapeutic option for HSCT-TMA, but HSCT patients appear to require higher medication dosing than recommended for other conditions. We also observed that a CH50 level ≤ 4 complement activity enzyme units correlated with therapeutic eculizumab levels and clinical response, and therefore CH50 may be useful to guide eculizumab dosing in HSCT patients as drug level monitoring is not readily available., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Noninvasive biomarkers are needed to assess immune risk and ultimately guide therapeutic decision-making following kidney transplantation. A requisite step toward these goals is validation of markers that diagnose and/or predict relevant transplant endpoints. The Clinical Trials in Organ Transplantation-01 protocol is a multicenter observational study of biomarkers in 280 adult and pediatric first kidney transplant recipients. We compared and validated urinary mRNAs and proteins as biomarkers to diagnose biopsy-proven acute rejection (AR) and stratify patients into groups based on risk for developing AR or progressive renal dysfunction. Among markers tested for diagnosing AR, urinary CXCL9 mRNA (odds ratio [OR] 2.77, positive predictive value [PPV] 61.5%, negative predictive value [NPV] 83%) and CXCL9 protein (OR 3.40, PPV 67.6%, NPV 92%) were the most robust. Low urinary CXCL9 protein in 6-month posttransplant urines obtained from stable allograft recipients classified individuals least likely to develop future AR or a decrement in estimated glomerular filtration rate between 6 and 24 months (92.5-99.3% NPV). Our results support using urinary CXCL9 for clinical decision-making following kidney transplantation. In the context of acute dysfunction, low values can rule out infectious/immunological causes of injury. Absent urinary CXCL9 at 6 months posttransplant defines a subgroup at low risk for incipient immune injury., (© Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Hematopoietic stem cell transplant (HSCT)-associated thrombotic microangiopathy (TMA) is a complication that occurs in 25% to 35% of HSCT recipients and shares histomorphologic similarities with hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). The hallmark of all thrombotic microangiopathies is vascular endothelial cell injury of various origins, resulting in microangiopathic hemolytic anemia, platelet consumption, fibrin deposition in the microcirculation, and tissue damage. Although significant advances have been made in understanding the pathogenesis of other thrombotic microangiopathies, post-HSCT TMA remains poorly understood. We report an analysis of the complement alternative pathway, which has recently been linked to the pathogenesis of both the Shiga toxin mediated and the atypical forms of HUS, with a focus on genetic variations in the complement Factor H (CFH) gene cluster and CFH autoantibodies in six children with post-HSCT TMA. We identified a high prevalence of deletions in CFH-related genes 3 and 1 (delCFHR3-CFHR1) and CFH autoantibodies in these patients with HSCT-TMA. Conversely, CFH autoantibodies were not detected in 18 children undergoing HSCT who did not develop TMA. Our observations suggest that complement alternative pathway dysregulation may be involved in the pathogenesis of post-HSCT TMA. These findings shed light on a novel mechanism of endothelial injury in transplant-TMA and may therefore guide the development of targeted treatment interventions.

BK virus is associated with hemorrhagic cystitis after hematopoietic stem cell transplantation (HSCT), although evidence supporting a causal relationship remains limited. Although BK viruria is common after HSCT, BK viremia may better predict clinically significant cystitis, similar to its predictive value for nephropathy after kidney transplantation. We hypothesized that BK viremia would precede hemorrhagic cystitis in a cohort of 88 consecutive children prospectively enrolled to originally study thrombotic microangiopathy in the first 100 days after allogeneic HSCT. Cox regression models with time-varying covariates assessed the association between different BK viremia cutoffs and the development of hemorrhagic cystitis, defined as at least macroscopic hematuria. Subjects with a peak plasma BK viral load 1 to 9999 copies/mL had an adjusted hazard ratio of 4.2 (95% confidence interval (CI), 1.3 to 13.7) for the development of hemorrhagic cystitis. Those with peak BK viremia >100,000 copies/mL had an adjusted hazard ratio of 116.8 (95% CI, 12 to 1136) for cystitis. Other independent risk factors for hemorrhagic cystitis included age >7 years and HHV-6 viremia. Neither graft-versus-host disease nor achieving engraftment increased the risk for cystitis. If therapeutic strategies are found to be effective, these observations may support screening for BK viremia after HSCT, as currently recommended for other DNA viruses., (Copyright © 2013 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: The mechanism of kidney injury in hematopoietic stem cell transplantation (HSCT)-associated thrombotic microangiopathy (TA-TMA) is not completely understood. Renal C4d staining is a marker of classic complement activation and endothelial injury and has been described in preliminary reports of HSCT recipients with TA-TMA. Our objective was to evaluate complement in the pathogenesis of small vessel injury in children receiving HSCT. We hypothesized that kidney tissue from children with TA-TMA would more frequently show C4d deposition compared with HSCT recipients without histologic TA-TMA., Methods: We reviewed kidney specimens (biopsy or autopsy) from children who had undergone HSCT at a single center. Using histologic criteria alone, subjects were divided into TA-TMA (n = 8) and non-TA-TMA (control) groups (n = 12). C4d staining was performed by immunohistochemistry and evaluated on arterioles, peritubular capillaries, glomeruli, and tubular basement membranes., Results: Diffuse or focal renal arteriolar C4d staining was more common in subjects with histologic TA-TMA (75%) compared with controls (8%). Rare peritubular capillary C4d staining was present in 50% of TA-TMA samples and was absent in controls. Glomerular C4d staining was seen at a similar frequency in cases and controls, whereas tubular basement membrane staining was less frequently observed and only in subjects with TA-TMA., Conclusions: Arteriolar C4d deposition may be a pathologic marker of TA-TMA, implicating localized complement fixation in HSCT recipients with kidney disease secondary to small vessel injury. Further studies to better characterize the preferential arteriolar C4d staining may identify a renal compartment of injury, possibly explaining the dramatic hypertension seen in TA-TMA.

Objective: To develop and evaluate a system for reliable and efficient individualized risk-based monitoring of cholesterol and 11 other tests after kidney transplantation in children., Methods: We identified system components that drive reliable individualized monitoring and used quality improvement methods to develop and implement interventions, including (1) monitoring schedules individualized by dyslipidemia risk assigned to each patient, (2) automated previsit decision support from our electronic medical record, (3) standardized work flow and responsibility, and (4) automated forwarding of results to providers. We measured the proportion of patients due for cholesterol testing who had it performed within 1 week of their clinic visit and the proportion of patients in our population who achieved low-density lipoprotein (LDL) cholesterol control at baseline and for 2 years after improved monitoring., Results: The proportion of visits in which cholesterol monitoring was completed when indicated improved from 80% to 98% within 8 months and was sustained for more than 1 year. The number of patients with controlled LDL (<130 mg/dL, 3.3 mmol/L) improved from 44 (71%) of 62 at the start of our project to 58 (94%) of 62 (P = .002) at an average follow-up of 24 months., Conclusions: Using quality improvement and health information technology, we achieved sustained, reliable and efficient personalized monitoring of cholesterol and 11 other tests. This approach enabled substantial improvement in LDL cholesterol control. Structured methods of system redesign that leverage information technology systems hold promise for rapidly achieving reliable individualized care in other settings.

Background and Objectives: Nephrotic syndrome (NS) represents a common disease in pediatric nephrology typified by a relapsing and remitting course and characterized by the presence of edema that can significantly affect the health-related quality of life in children and adolescents. The PROMIS pediatric measures were constructed to be publically available, efficient, precise, and valid across a variety of diseases to assess patient reports of symptoms and quality of life. This study was designed to evaluate the ability of children and adolescents with NS to complete the PROMIS assessment via computer and to initiate validity assessments of the short forms and full item banks in pediatric NS. Successful measurement of patient reported outcomes will contribute to our understanding of the impact of NS on children and adolescents., Design: This cross-sectional study included 151 children and adolescents 8-17 years old with NS from 16 participating institutions in North America. The children completed the PROMIS pediatric depression, anxiety, social-peer relationships, pain interference, fatigue, mobility and upper extremity functioning measures using a web-based interface. Responses were compared between patients experiencing active NS (n = 53) defined by the presence of edema and patients with inactive NS (n = 96) defined by the absence of edema., Results: All 151 children and adolescents were successfully able to complete the PROMIS assessment via computer. As hypothesized, the children and adolescents with active NS were significantly different on 4 self-reported measures (anxiety, pain interference, fatigue, and mobility). Depression, peer relationships, and upper extremity functioning were not different between children with active vs. inactive NS. Multivariate analysis showed that the PROMIS instruments remained sensitive to NS disease activity after adjusting for demographic characteristics., Conclusions: Children and adolescents with NS were able to successfully complete the PROMIS instrument using a web-based interface. The computer based pediatric PROMIS measurement effectively discriminated between children and adolescents with active and inactive NS. The domain scores found in this study are consistent with previous reports investigating the health-related quality of life in children and adolescents with NS. This study establishes known-group validity and feasibility for PROMIS pediatric measures in children and adolescents with NS.

Background: The use of therapeutic plasma exchange (TPE) in hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) is controversial because the exact mechanism of injury in TA-TMA is not yet understood., Study Design and Methods: The study objective was to retrospectively review the outcome of children receiving TPE for TA-TMA at our institution. We hypothesized that patients initiating TPE earlier in their disease course would receive a greater benefit than those starting later, regardless of the therapeutic mechanism., Results: We identified 10 consecutive pediatric patients with TA-TMA treated with TPE. Nine of these patients showed normalization of the laboratory variables associated with microangiopathy during their TPE course, but only five patients recovered renal function and survived TA-TMA. The five survivors started TPE a median of 17 days (range, 4-25 days) after TA-TMA diagnosis while the five patients who died started TPE a median of 32 days (range, 17-73 days) after TA-TMA was diagnosed. Three of the five survivors had multiorgan failure at TA-TMA diagnosis and completely recovered with early institution of TPE. These three survivors were able to discontinue renal replacement therapy, and all achieved a normal posttreatment creatinine. The five patients with later institution of TPE progressed to end-stage renal disease and all died. There were no serious TPE-related complications in either group., Conclusion: This is the first report evaluating TPE response in regard to procedure initiation time after TA-TMA diagnosis. Our data suggests that early initiation of TPE might be beneficial even in patients with multiorgan failure due to TA-TMA., (© 2012 American Association of Blood Banks.)

Background: Guidelines differ on screening recommendations for latent tuberculosis infection (LTBI) prior to immunosuppressive therapy. We aimed to determine the most cost-effective LTBI screening strategy before long-term steroid therapy in a child with new-onset idiopathic nephrotic syndrome., Study Design: Markov state-transition model., Setting & Population: 5-year-old boy with new-onset idiopathic nephrotic syndrome., Model, Perspective, & Timeframe: The Markov model took a societal perspective over a lifetime horizon., Intervention: 3 strategies were compared: universal tuberculin skin testing (TST), targeted screening using a risk-factor questionnaire, and no screening. A secondary model included the newer interferon γ release assays (IGRAs), requiring only one visit and having greater specificity than TST., Outcomes: Marginal cost-effectiveness ratios (2010 US dollars) with effectiveness measured as quality-adjusted life-years (QALYs)., Results: At an LTBI prevalence of 1.1% (the average US childhood prevalence in our base case), a no-screening strategy dominated ($2,201; 29.3356 QALYs) targeted screening ($2,218; 29.3356 QALYs) and universal TST ($2,481; 29.3347 QALYs). At a prevalence >10.3%, targeted screening with a risk-factor questionnaire was the most cost-effective option. Higher than a prevalence of 58.5%, universal TST was preferred. In the secondary model, targeted screening with a questionnaire followed by IGRA testing was cost-effective compared with no screening in the base case when the LTBI prevalence was >4.9%., Limitations: There is no established gold standard for the diagnosis of LTBI. Results of any modeling task are limited by the accuracy of available data., Conclusions: Prior to starting steroid therapy, only patients in areas with a high prevalence of LTBI will benefit from universal TST. As more evidence becomes available about the use of IGRA testing in children, the assay may become a component of cost-effective screening protocols in populations with a higher burden of LTBI., (Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

In a cross-sectional study, we assessed effects of calcineurin inhibitor (CNI) or rapamycin on T-regulatory (Treg) cells from children with stable liver (n = 53) or kidney (n = 9) allografts several years posttransplant. We analyzed Treg number, phenotype, suppressive function, and methylation at the Treg-specific demethylation region (TSDR) using Tregs and peripheral blood mononuclear cells. Forty-eight patients received CNI (39 as monotherapy) and 12 patients received rapamycin (9 as monotherapy). Treg numbers diminished over time on either regimen, but reached significance only with CNI (r =-0.424, p = 0.017). CNI levels inversely correlated with Treg number (r =-0.371, p = 0.026), and positively correlated with CD127+ expression by Tregs (r = 0.437, p = 0.023). Patients with CNI levels >3.6 ng/mL had weaker Treg function than those with levels <3.6 ng/mL, whereas rapamycin therapy positively correlated with Treg numbers (r = 0.628, p = 0.029) and their expression of CTLA4 (r = 0.726, p = 0.041). Overall, CTLA4 expression, TSDR demethylation and an absence of CD127 were important for Treg suppressive function. We conclude that rapamycin has beneficial effects on Treg biology, whereas long-term and high dose CNI use may impair Treg number, function and phenotype, potentially acting as a barrier to attaining host hyporesponsiveness to an allograft., (© Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Advances in immunosuppression have facilitated increased use of steroid-avoidance protocols in pediatric kidney transplantation. To evaluate such steroid avoidance, a retrospective cohort analysis of pediatric kidney transplant recipients between 2002 and 2009 in the United Network for Organ Sharing database was performed. Outcomes (acute rejection and graft loss) in steroid-based and steroid-avoidance protocols were assessed in 4627 children who received tacrolimus and mycophenolate immunosuppression and did not have multiorgan transplants. Compared to steroid-based protocols, steroid avoidance was associated with decreased risk of acute rejection at 6 months posttransplant (8.3% vs. 10.9%, p = 0.02) and improved 5-year graft survival (84% vs. 78%, p < 0.001). However, patients not receiving steroids experienced less delayed graft function (p = 0.01) and pretransplant dialysis, were less likely to be African-American and more frequently received a first transplant from a living donor (all p < 0.001). In multivariate analysis, steroid avoidance trended toward decreased acute rejection at 6 months, but this no longer reached statistical significance, and there was no association of steroid avoidance with graft loss. We conclude that, in clinical practice, steroid avoidance appears safe with regard to graft rejection and loss in pediatric kidney transplant recipients at lower immunologic risk., (© Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Mycophenolic acid (MPA) exposure in pediatric patients with kidney transplant receiving body surface area (BSA)-based dosing exhibits large variability. Several genetic variants in glucuronosyltransferases (UGTs) and of multidrug resistance-associated protein 2 (MRP2) have independently been suggested to predict MPA exposure in adult patients with varying results. Here, the combined contribution of these genetic variants to MPA pharmacokinetic variability was investigated in pediatric renal transplant recipients who were on mycophenolic mofetil maintenance therapy., Methods: MPA and MPA-glucuronide concentrations from 32 patients were quantified by high-performance liquid chromatography. MPA exposure (AUC) was estimated using a 4-point abbreviated sampling strategy (predose/trough and 20 minutes, 1 hour, and 3 hours after dose) using a validated pediatric Bayesian estimator. Genotyping was performed for all of the following single nucleotide polymorphisms (SNPs): UGT1A8 830G>A(*3), UGT1A9 98T>C(*3), UGT1A9-440C>T, UGT1A9-2152C>T, UGT1A9-275T>A, UGT2B7-900A>G, and MRP2-24T>C., Results: Recipients heterozygous for MRP2-24T>C who also had UGT1A9-440C>T or UGT2B7-900A>G (n = 4), and MRP2-24T>C-negative recipients having both UGT1A9-440C>T and UGT2B7-900A>G (n = 5) showed a 2.2 and 1.7 times higher dose-dependent and BSA-normalized MPA-AUC compared with carriers of no or only 1 UGT-SNP (P < 0.001 and P = 0.01, respectively) (n = 7). Dose-dependent and BSA-normalized predose MPA concentrations were 3.0 and 2.4 times higher, respectively (P < 0.001). Interindividual variability in peak concentrations could be explained by the presence of the UGT1A9-440C>T genotype (P < 0.05)., Conclusion: Our preliminary study demonstrates that combined UGT1A9-440C>T, UGT2B7-900A>G, and MRP2-24T>C polymorphisms can be important predictors of interindividual variability in MPA exposure in the pediatric population.

Formal evaluation of kidney function is essential to determine chemotherapy dosing based on established treatment protocols in children undergoing autologous stem cell transplantation. Cystatin C has been widely studied as a marker of the glomerular filtration rate (GFR), although data regarding its use in stem cell transplantation are limited. We evaluated the performance of cystatin C-based equations and determined their sensitivity to detect a nuclear GFR of <100 mL/min/1.73 m(2) in children undergoing autologous transplantation. We performed a retrospective cohort analysis in 16 children undergoing 26 transplantations using a modified Bland-Altman analysis to account for repeated measures. Cystatin C-based equations published by Hoek, Le Bricon, Rule, Filler, Zappitelli, Larsson, and Schwartz (the New Chronic Kidney Disease in Children formula, New CKiD formula) were evaluated and compared to the creatinine-based modified Schwartz equation. We found that cystatin C-based equations demonstrated improved sensitivity to detect a nuclear GFR of <100 mL/min/1.73 m(2) compared to the creatinine-based modified Schwartz equation, which significantly overestimated GFR. Most cystatin C-based equations, however, tended to underestimate the nuclear GFR. The New CKiD formula, combining cystatin C and creatinine, offered a sensitivity of 100% and a specificity of 95% for detecting a nuclear GFR <100 mL/min/1.73 m(2). Institutions using cystatin C-based GFR estimation should be aware of the specific prediction formula and GFR measurement techniques available at their center, as each method's performance can vary considerably. As more research becomes available, this easily measured marker should become a valuable component of GFR estimation, providing cost savings (a nuclear GFR is 5.5 times more costly than a cystatin C) and reducing radiation exposure., (Copyright © 2012 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Tick-borne diseases are of increasing concern in many countries, particularly as a consequence of changes in land use and climate. Ticks are vectors of numerous pathogens (viruses, bacteria, protozoa) that can be harmful to humans and animals. In the context of animal health, bovine babesiosis poses a recurrent threat to cattle herds. In this study, we use a modeling approach to investigate the spread of babesiosis and evaluate control measures. A previously developed tick population dynamics model (here, Ixodes ricinus) is coupled with a pathogen spread model (here, the protozoan Babesia divergens), which describes pathogen spread in a dairy herd through the following processes: transmission, acquisition, transovarial transmission, transstadial persistence, and clearance of the pathogen. An assessment of the simulated B. divergens prevalence levels in ticks and cattle in the context of existing knowledge and data suggested that the model provides a realistic representation of pathogen spread. The model was then used to evaluate the influence of host density and the effect of acaricides on B. divergens prevalence in cattle. Increasing deer density results in an increase in prevalence in cattle whereas increasing cattle stocking rate results in a slight decrease. A potential increase in deer density would thus have an amplification effect on disease spread due to the increase in the number of infected ticks. Regular use of acaricides produces a reduction in pathogen prevalence in cattle. This model could be adapted to other tick-borne diseases., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Purpose: Targeting tubulin binders to cancer cells using antibody-drug conjugates (ADCs) has great potential to become an effective cancer treatment with low normal tissue toxicity. The nature of the linker used to tether the tubulin binder to the antibody and the conjugation sites on the antibody and the small molecule are important factors in the ADC stability and effectiveness., Methods: We explored the use of tubulin-targeting dolastatin 15 derivatives (Dol15) tethered covalently to a representative antibody, trastuzumab, via cleavable and non-cleavable linkers at varying antibody reactive sites (i.e., lysine residues, partially reduced hinge region disulfide bonds) and drug coupling sites (i.e., C-terminus, N-terminus), to investigate which constructs were more effective in killing HER2-positive cells in vitro and in vivo., Results: We found that Dol15 conjugated to trastuzumab via lysine residues at the drug C-terminus using a non-cleavable linker (trastuzumab-amide-C-term-Dol15) produced target-dependent growth inhibition of cells endogenously expressing high HER2 levels (i.e., SK-BR-3, SK-OV-3) in vitro. This ADC was effective at varying doses (i.e., 10 and 20 mg/kg) in the SK-OV-3 human ovarian cancer xenograft., Conclusions: Tethering Dol15 via partially reduced disulfide bonds at the drug C-terminus via a non-cleavable linker (trastuzumab-MC-C-term-Dol15) resulted in an equally effective ADC in vitro, showing that site of antibody conjugation did not influence ADC activity. However, tethering Dol15 at the drug N-terminus using non-cleavable and cleavable linkers (trastuzumab-MC-N-term-Dol15 and trastuzumab-MC-VC-PABC-N-term-Dol15, respectively) resulted in ineffective ADCs. Thus, Dol15 tethered at the C-terminus may be a useful tubulin-targeting agent for conjugation at various antibody reactive sites.