Long-term outcome of Hurler syndrome patients after hematopoietic cell transplantation: an international multicenter study.

Mucopolysaccharidosis type I-Hurler syndrome (MPS-IH) is a lysosomal storage disease characterized by multisystem morbidity and death in early childhood. Although hematopoietic cell transplantation (HCT) has been performed in these patients for more than 30 years, large studies on the long-term outcome of patients with MPS-IH after HCT are lacking. The goal of this international study was to identify predictors of the long-term outcome of patients with MPS-IH after successful HCT. Two hundred seventeen patients with MPS-IH successfully engrafted with a median follow-up age of 9.2 years were included in this retrospective analysis. Primary endpoints were neurodevelopmental outcomes and growth. Secondary endpoints included neurologic, orthopedic, cardiac, respiratory, ophthalmologic, audiologic, and endocrinologic outcomes. Considerable residual disease burden was observed in the majority of the transplanted patients with MPS-IH, with high variability between patients. Preservation of cognitive function at HCT and a younger age at transplantation were major predictors for superior cognitive development posttransplant. A normal α-l-iduronidase enzyme level obtained post-HCT was another highly significant predictor for superior long-term outcome in most organ systems. The long-term prognosis of patients with MPS-IH receiving HCT can be improved by reducing the age at HCT through earlier diagnosis, as well as using exclusively noncarrier donors and achieving complete donor chimerism.

Involvement of AMP-activated protein kinase in mediating pyrrolo-1,5-benzoxazepine-induced apoptosis in neuroblastoma cells.

Neuroblastoma, a paediatric malignancy of the sympathetic nervous system, accounts for 15 % of childhood cancer deaths. Despite advances in understanding the biology, it remains one of the most difficult paediatric cancers to treat partly due to the development of multidrug resistance. There is thus a compelling demand for new treatment strategies that can bypass resistance mechanisms. The pyrrolo-1,5-benzoxazepine (PBOX) compounds are a series of novel microtubule-targeting agents that potently induce apoptosis in various tumour models. We have previously reported that PBOX compounds induce apoptosis in drug sensitive and multidrug resistant neuroblastoma cells and synergistically enhance apoptosis induced by chemotherapeutics such as carboplatin. In this study we present further data concerning the molecular basis of PBOX-induced apoptosis in neuroblastoma. We demonstrate that PBOX-6 induced AMP-activated protein kinase (AMPK) activation and downstream acetyl-CoA carboxylase phosphorylation. Increased reactive oxygen species (ROS) appeared to serve as the upstream signal for AMPK activation as pretreatment of cells with the antioxidant N-acetylcysteine inhibited both AMPK activation and PBOX-induced apoptosis. Furthermore, activation of AMPK by PBOX-6 was found to inhibit mTOR complex 1 (mTORC1) signalling. Finally, we demonstrate the efficacy of PBOX-6 in an in vivo xenograft model of neuroblastoma. This study provides new insights into understanding the molecular and cellular mechanisms involved in PBOX-induced cell death in neuroblastoma and further supports their future use as novel anti-cancer agents for the treatment of neuroblastoma.

A Long-term Retrospective Evaluation of Functional and Radiographic Outcomes of Pediatric Hip Surgery in Hurler Syndrome.

BACKGROUND: After successful hematopoietic stem cell transplantation, maintaining function and mobility have become key goals in the management of patients with Hurler syndrome, (mucopolysaccharoidosis type 1H). The aim of this study was to establish the functional and radiologic outcomes after hip surgery in patients with this condition who had reached skeletal maturity. METHODS: We prospectively followed 13 mucopolysaccharoidosis type 1H patients with closed triradiate cartilages who had undergone hip surgery in a single institution (Our Lady's Children's Hospital, Crumlin) in early childhood, after successful hematopoietic stem cell transplantation. Functional assessment was performed using the Harris Hip Score. Acetabular and femoral head morphology were defined using a pelvic radiograph. RESULTS: The average age at follow-up was 18.6 years (range, 13.2 to 23.8 y). The average length of follow-up from surgical intervention was 14.6 years (range, 10.3 to 21.6 y). The average Harris Hip Score at follow-up was 61.0 (range, 19 to 91). At follow-up, 4 patients were either wheelchair bound or required a walking frame to mobilize in the community. At follow-up, all hips were in-joint with an average center edge angle of 37.7 degrees (range, 0 to 63 degrees). All hips displayed characteristic medial flattening of the femoral head. Ten hips (of 26 hips) showed radiologic degenerative changes with loss of joint space <2 mm. CONCLUSIONS: Despite the surgical provision of stable well-covered hips, active intervention did not prevent the development of radiologic deterioration and clinically significant hip arthritis. We recommend that pediatric hip surgery in Hurler syndrome be designed with the possibility of early hip replacement in mind. LEVEL OF EVIDENCE: Level III.

Outcomes of transplantation using various hematopoietic cell sources in children with Hurler syndrome after myeloablative conditioning.

We report transplantation outcomes of 258 children with Hurler syndrome (HS) after a myeloablative conditioning regimen from 1995 to 2007. Median age at transplant was 16.7 months and median follow-up was 57 months. The cumulative incidence of neutrophil recovery at day 60 was 91%, acute graft-versus-host disease (GVHD) (grade II-IV) at day 100 was 25%, and chronic GVHD and 5 years was 16%. Overall survival and event-free survival (EFS) at 5 years were 74% and 63%, respectively. EFS after HLA-matched sibling donor (MSD) and 6/6 matched unrelated cord blood (CB) donor were similar at 81%, 66% after 10/10 HLA-matched unrelated donor (UD), and 68% after 5/6 matched CB donor. EFS was lower after transplantation in 4/6 matched unrelated CB (UCB) (57%; P = .031) and HLA-mismatched UD (41%; P = .007). Full-donor chimerism (P = .039) and normal enzyme levels (P = .007) were higher after CB transplantation (92% and 98%, respectively) compared with the other grafts sources (69% and 59%, respectively). In conclusion, results of allogeneic transplantation for HS are encouraging, with similar EFS rates after MSD, 6/6 matched UCB, 5/6 UCB, and 10/10 matched UD. The use of mismatched UD and 4/6 matched UCB was associated with lower EFS.

New autoimmune diseases after cord blood transplantation: a retrospective study of EUROCORD and the Autoimmune Disease Working Party of the European Group for Blood and Marrow Transplantation.

To describe the incidence, risk factors, and treatment of autoimmune diseases (ADs) occurring after cord blood transplantation (CBT), we analyzed both CBT recipients reported to EUROCORD who had developed at least 1 new AD and those who had not. Fifty-two of 726 reported patients developed at least 1 AD within 212 days (range, 27-4267) after CBT. Cumulative incidence of ADs after CBT was 5.0% +/- 1% at 1 year and 6.6% +/- 1% at 5 years. Patients developing ADs were younger and had more nonmalignant diseases (P < .001). ADs target hematopoietic (autoimmune hemolytic anemia, n = 20; Evans syndrome, n = 9; autoimmune thrombocytopenia, n = 11; and immune neutropenia, n = 1) and other tissues (thyroiditis, n = 3; psoriasis, n = 2; Graves disease, n 1; membranous glomerulonephritis, n = 2; rheumatoid arthritis, n = 1; ulcerative colitis, n = 1; and systemic lupus erythematosus, n = 1). Four patients developed 2 ADs (3 cases of immune thrombocytopenia followed by autoimmune hemolytic anemia and 1 Evans syndrome with rheumatoid arthritis). By multivariate analysis, the main risk factor for developing an AD was nonmalignant disease as an indication for CBT (P = .0001). Hematologic ADs were most often treated with steroids, rituximab, and cyclosporine. With a median follow-up of 26 months (range, 2-91), 6 of 52 patients died as a consequence of ADs. We conclude that CBT may be followed by potentially life-threatening, mainly hematologic ADs.

Defibrotide for prophylaxis of hepatic veno-occlusive disease in paediatric haemopoietic stem-cell transplantation: an open-label, phase 3, randomised controlled trial.

BACKGROUND: Hepatic veno-occlusive disease is a leading cause of morbidity and mortality after haemopoietic stem-cell transplantation (HSCT). We aimed to assess whether defibrotide can reduce the incidence of veno-occlusive disease in this setting. METHODS: In our phase 3 open-label, randomised controlled trial, we enrolled patients at 28 European university hospitals or academic medical centres. Eligible patients were younger than 18 years, had undergone myeloablative conditioning before allogeneic or autologous HSCT, and had one or more risk factor for veno-occlusive disease based on modified Seattle criteria. We centrally assigned eligible participants on the basis of a computer-generated randomisation sequence (1:1), stratified by centre and presence of osteopetrosis, to receive intravenous defibrotide prophylaxis (treatment group) or not (control group). The primary endpoint was incidence of veno-occlusive disease by 30 days after HSCT, adjudicated by a masked, independent review committee, in eligible patients who consented to randomisation (intention-to-treat population), and was assessed with a competing risk approach. Patients in either group who developed veno-occlusive disease received defibrotide for treatment. We assessed adverse events to 180 days after HSCT in all patients who received allocated prophylaxis. This trial is registered with ClinicalTrials.gov, number NCT00272948. FINDINGS: Between Jan 25, 2006, and Jan 29, 2009, we enrolled 356 eligible patients to the intention-to-treat population. 22 (12%) of 180 patients randomly allocated to the defibrotide group had veno-occlusive disease by 30 days after HSCT compared with 35 (20%) of 176 controls (risk difference -7·7%, 95% CI -15·3 to -0·1; Z test for competing risk analysis p=0·0488; log-rank test p=0·0507). 154 (87%) of 177 patients in the defibrotide group had adverse events by day 180 compared with 155 (88%) of 176 controls. INTERPRETATION: Defibrotide prophylaxis seems to reduce incidence of veno-occlusive disease and is well tolerated. Thus, such prophylaxis could present a useful clinical option for this serious complication of HSCT. FUNDING: Gentium SpA, European Group for Blood and Marrow Transplantation.

The use of complementary and alternative medicine by irish pediatric cancer patients.

INTRODUCTION: The use of complementary and alternative medicine (CAM) in the Irish pediatric cancer setting has not previously been established. METHODS: To investigate the prevalence and predictors of CAM use in this group of patients, an anonymous cross-sectional survey was offered to all carers of patients either on or off treatment for malignancy at a single pediatric cancer center over an 8-week period. RESULTS: Of a total of 220 questionnaires distributed, 98 (43%) were returned. Six were excluded because of inadequate data. A total of 58% of children were male and the mean age was 9 years. The most common cancer diagnosis was leukemia (45%). Fifty-two respondents (57%) said their child had used or was using CAM, and 55% of whom had started since their cancer diagnosis. The most common types of CAM used were vitamins and minerals (18%), reflexology (11%), dietary supplements (11%), faith healers (9%), and energy therapies (9%). The most common reason for CAM use was to improve physical well-being (31%). A total of 65% of CAM users had not told their doctor that they were doing so. Of the 52 CAM users, 30 (58%) were using oral CAM medication. A total of 86% of CAM users reported benefit from the treatment, and no respondent reported side effects.There was no significant relationship between sex, tumor type, age, income, previous treatment, and CAM use. Where parents had a higher level of education, children were more likely to use CAM (P=0.035.) There was a statistically significant relationship between respondents rating of conventional therapy and CAM use (P=0.007). Interestingly, parents who were satisfied with conventional therapy were more likely to use CAM. CONCLUSION: The high prevalence of CAM use demonstrated in this study and particularly the high use of CAM medication therapies underlines the importance of physicians asking routinely about CAM use in this population.

Persistent complete response after single-agent sunitinib treatment in a case of TFE translocation positive relapsed metastatic pediatric renal cell carcinoma.

Forty percent of renal cell carcinomas (RCCs) in childhood are characterized by translocation involving transcription factor E3 (TFE3) family members. Here, we describe a case of TFE3-positive RCC in which metastatic relapse to the mediastinal lymph nodes and pulmonary nodules was treated with single-agent sunitinib, a multitargeted tyrosine inhibitor. Complete radiologic remission was achieved after only 3 courses of treatment, and surgical exploration of metastases failed to identify any residual viable disease. The published experience of sunitinib in TFE-RCC is limited, and prospective evaluation of its activity in a larger number of patients is warranted.

Foot and ankle abnormalities in the Hurler syndrome: additions to the phenotype.

BACKGROUND: After successful hematopoietic stem cell transplantation maintaining function and mobility has become the key goal in the management of patients with mucopolysaccharoidosis type 1 (MPS-1). We detail the foot and ankle pathology in 18 patients with MPS-1 managed in our unit. METHODS: Functional assessment was performed using the Oxford Foot and Ankle Questionnaire for children (OxAFQ-C). Morphologic assessment was performed by means of a mirrored foot photograph box, the Foot Posture Index (FPI), and clinical photography. Standardized radiologic investigations were sought when clinically warranted. Average lateral talus-first metatarsal angle, anteroposterior and lateral talocalcaneal angles, and lateral distal tibial angle (LDTA) were determined. RESULTS: The average patient-reported OxAFQ-C score was 44.7 (range, 10 to 60). The average proxy-reported OxAFQ-C score was 45.7 (range, 11 to 60). Ten of the 18 patients wore customized footwear. Of the 36 feet examined 11 were found scored as "highly pronated" (FPI>+9), 12 feet had a "pronated posture" (FPI +6 to +9), and 13 feet were found to have a "normal posture" (FPI 0 to +5). Thirteen of the 18 (72%) patients studied had curly toes. The average talus-first metatarsal angle recorded was 10.7 degrees (range, -7 to 30 degrees). The average lateral and anteroposterior talocalcaneal angles were 45.8 degrees (range, 16 to 62 degrees) and 31 degrees (range, 1 to 51 degrees), respectively. The average LDTA was found to be 70.6 degrees (range, 48 to 82 degrees). A single-sample Student t test shows significant divergence of measured LDTA, OxAFQ-C, and FPI from normal populations (P<0.005). CONCLUSIONS: MPS-1 is associated with a significant degree of foot and ankle pathology that has not been previously described. We found a high incidence of curly toes, ankle valgus, functional foot, and ankle disability and a requirement for customized footwear among our cohort. We recommend that careful assessment of foot and ankle pathology should be routine in the interdisciplinary management of patients with MPS-1. LEVEL OF EVIDENCE: Level III.

MicroRNA-184 inhibits neuroblastoma cell survival through targeting the serine/threonine kinase AKT2.

BACKGROUND: Neuroblastoma is a paediatric cancer of the sympathetic nervous system. The single most important genetic indicator of poor clinical outcome is amplification of the MYCN transcription factor. One of many down-stream MYCN targets is miR-184, which is either directly or indirectly repressed by this transcription factor, possibly due to its pro-apoptotic effects when ectopically over-expressed in neuroblastoma cells. The purpose of this study was to elucidate the molecular mechanism by which miR-184 conveys pro-apoptotic effects. RESULTS: We demonstrate that the knock-down of endogenous miR-184 has the opposite effect of ectopic up-regulation, leading to enhanced neuroblastoma cell numbers. As a mechanism of how miR-184 causes apoptosis when over-expressed, and increased cell numbers when inhibited, we demonstrate direct targeting and degradation of AKT2, a major downstream effector of the phosphatidylinositol 3-kinase (PI3K) pathway, one of the most potent pro-survival pathways in cancer. The pro-apoptotic effects of miR-184 ectopic over-expression in neuroblastoma cell lines is reproduced by siRNA inhibition of AKT2, while a positive effect on cell numbers similar to that obtained by the knock-down of endogenous miR-184 can be achieved by ectopic up-regulation of AKT2. Moreover, co-transfection of miR-184 with an AKT2 expression vector lacking the miR-184 target site in the 3'UTR rescues cells from the pro-apoptotic effects of miR-184. CONCLUSIONS: MYCN contributes to tumorigenesis, in part, by repressing miR-184, leading to increased levels of AKT2, a direct target of miR-184. Thus, two important genes with positive effects on cell growth and survival, MYCN and AKT2, can be linked into a common genetic pathway through the actions of miR-184. As an inhibitor of AKT2, miR-184 could be of potential benefit in miRNA mediated therapeutics of MYCN amplified neuroblastoma and other forms of cancer.

Successful allogeneic bone marrow transplant for Niemann-Pick disease type C2 is likely to be associated with a severe 'graft versus substrate' effect.

Niemann-Pick disease type C2 (NPC2) is caused by the inherited deficiency of a lysosomal cholesterol transport protein, NPC2 protein. Many cases of NPC2 present in early infancy with inflammatory lung disease, with subsequent severe neurological disease and death in early childhood. This disease is theoretically correctable by bone marrow transplantation (BMT), as the NPC2 protein is small and soluble and secreted and recaptured by the mannose-6-phosphate pathway. In this report we describe the first successful allogeneic bone marrow transplantation for this condition in a 16-month-old boy homozygous for the NPC2 p.E20X mutation, which has hitherto been reported to cause disease with a severe phenotype. During BMT there was an initial improvement of the established respiratory illness, with the immune suppression associated with transplant conditioning, but there was subsequent marked deterioration at the time of immune reconstitution and donor cell engraftment. This 'graft versus substrate' reaction was managed with intensive immune suppressant therapy, and it gradually resolved as the substrate was cleared by the engrafted donor macrophages. All immune suppression was withdrawn 18 months after transplantation, and his respiratory illness has resolved. He walked independently at 24 months and is continuing to reach development milestones after receiving his transplant. We conclude that the successful treatment of Niemann-Pick C2 therefore seems likely to be associated with a severe post-transplantation 'graft versus substrate' reaction that requires intense immune suppression before eventual resolution.

Risk factor analysis of outcomes after unrelated cord blood transplantation in patients with hurler syndrome.

Allogeneic stem cell transplantation (SCT) is considered effective in preventing disease progression in patients with Hurler syndrome (HS). Unrelated umbilical cord blood (UCB) grafts are suggested as an alternative to bone marrow (BM) or peripheral blood stem cells (PBSC). We studied 93 HS patients receiving an UCB graft to analyze risk factors for outcomes. The median time from diagnosis to transplant was 4.6 months, median follow-up was 29 months, and median number of nucleated CB cells infused was 7.6 x 10(7)/kg. Most of the patients received 1 or 2 HLA disparate grafts, and the most frequently used conditioning regimen was cyclophosphamide + busulfan (Bu/Cy). All patients received anti-T cell antibody. At post transplant day +60, the cumulative incidence of neutrophil engraftment was 85%. A younger age at transplant and a higher CD34(+) dose at infusion were favorably associated with engraftment. With the exception of 2 patients, all engrafted patients achieved full and sustained donor chimerism. The 3-year event-free survival (EFS) and 3-year overall survival (OS) rates were 70% and 77%, respectively. In a multivariate analyses, use of Bu/Cy and a shorter interval from diagnosis to transplant were predictors for improved EFS rate (82% for patients transplanted within 4.6 months after diagnosis compared to 57% for the rest). Improved outcomes from early transplantation and immediate availability of CB unit lead us to conclude that CB transplantation is a beneficial option, which should be considered expediently for children with HS.

Improved metabolic correction in patients with lysosomal storage disease treated with hematopoietic stem cell transplant compared with enzyme replacement therapy.

We compared substrate reduction in patients with lysosomal storage disorder treated with hematopoietic stem cell transplant and found that it was significantly reduced compared with patients treated with pharmacological enzyme replacement therapy. These data might support the wider application of hematopoietic stem cell transplant in the treatment of lysosomal storage disorders.

High-resolution analysis of chromosomal breakpoints and genomic instability identifies PTPRD as a candidate tumor suppressor gene in neuroblastoma.

Although neuroblastoma is characterized by numerous recurrent, large-scale chromosomal imbalances, the genes targeted by such imbalances have remained elusive. We have applied whole-genome oligonucleotide array comparative genomic hybridization (median probe spacing 6 kb) to 56 neuroblastoma tumors and cell lines to identify genes involved with disease pathogenesis. This set of tumors was selected for having either 11q loss or MYCN amplification, abnormalities that define the two most common genetic subtypes of metastatic neuroblastoma. Our analyses have permitted us to map large-scale chromosomal imbalances and high-level amplifications at exon-level resolution and to identify novel microdeletions and duplications. Chromosomal breakpoints (n = 467) generating imbalances >2 Mb were mapped to intervals ranging between 6 and 50 kb in size, providing substantial information on each abnormality. For example, breakpoints leading to large-scale hemizygous loss of chromosome 11q were highly clustered and preferentially associated with segmental duplications. High-level amplifications of MYCN were extremely complex, often resulting in a series of discontinuous regions of amplification. Imbalances (n = 540) <2 Mb long were also detected. Although the majority (78%) of these imbalances mapped to segmentally duplicated regions and primarily reflect constitutional copy number polymorphisms, many subtle imbalances were detected that are likely somatically acquired alterations and include genes involved with tumorigenesis, apoptosis, or neural cell differentiation. The most frequent microdeletion involved the PTPRD locus, indicating a possible tumor suppressor function for this gene.

Quality of life of Hurler syndrome patients after successful hematopoietic stem cell transplantation.

Hurler syndrome (HS) is a lysosomal storage disease characterized by multisystem morbidity and death in early childhood. Hematopoietic stem cell transplantation (HSCT) results in long-term survival, although with significant residual disease burden. How this residual disease affects the health-related quality of life is unknown. Therefore, we conducted a multicenter cohort study on functional and psychosocial health and compared the outcomes to normative data using the Child Health Questionnaire and Pediatric Outcomes Data Collection Instrument. Perception of care was evaluated by the Measure of Processes of Care questionnaire. Sixty-three HS patients receiving HSCT with at least 3 years of follow-up after HSCT were included. The influence of potential predictors was analyzed using linear regression analysis, and correlation analysis was performed using Spearman rank correlation. Functional health of transplanted HS patients was significantly diminished compared with normative data (median physical summary z score, -2.4 [range, -3.5 to -1.6]; median global functioning z score, -3.2 [range, -4.8 to -1.8]). Psychosocial health was comparable or only slightly reduced compared with healthy peers (median psychosocial summary z score, 0.15 [range, -0.7 to 0.8]). A higher obtained lysosomal enzyme level post-HSCT predicted for superior functional health. Overall, parents were satisfied with the care received. Functional health of transplanted HS patients appeared significantly more affected than psychosocial health. To improve functional health, the use of only noncarrier donors and striving to achieve full-donor chimerism, both resulting in higher enzyme levels, is advised. Assessing the health-related quality of life could play an important role in evaluating outcomes of HS patients receiving novel (cell) therapies, including autologous gene-transduced HSCT.

Unequivocal delineation of clinicogenetic subgroups and development of a new model for improved outcome prediction in neuroblastoma.

PURPOSE: Neuroblastoma is a genetically heterogeneous pediatric tumor with a remarkably variable clinical behavior ranging from widely disseminated disease to spontaneous regression. In this study, we aimed for comprehensive genetic subgroup discovery and assessment of independent prognostic markers based on genome-wide aberrations detected by comparative genomic hybridization (CGH). MATERIALS AND METHODS: Published CGH data from 231 primary untreated neuroblastomas were converted to a digitized format suitable for global data mining, subgroup discovery, and multivariate survival analyses. RESULTS: In contrast to previous reports, which included only a few genetic parameters, we present here for the first time a strategy that allows unbiased evaluation of all genetic imbalances detected by CGH. The presented approach firmly established the existence of three different clinicogenetic subgroups and indicated that chromosome 17 status and tumor stage were the only independent significant predictors for patient outcome. Important new findings were: (1) a normal chromosome 17 status as a delineator of a subgroup of presumed favorable-stage tumors with highly increased risk; (2) the recognition of a survivor signature conferring 100% 5-year survival for stage 1, 2, and 4S tumors presenting with whole chromosome 17 gain; and (3) the identification of 3p deletion as a hallmark of older age at diagnosis. CONCLUSION: We propose a new regression model for improved patient outcome prediction, incorporating tumor stage, chromosome 17, and amplification/deletion status. These findings may prove highly valuable with respect to more reliable risk assessment, evaluation of clinical results, and optimization of current treatment protocols.

Progression of Hip Dysplasia in Mucopolysaccharidosis Type I Hurler After Successful Hematopoietic Stem Cell Transplantation.

BACKGROUND: Dysostosis multiplex contributes substantially to morbidity in patients with Hurler syndrome (mucopolysaccharidosis type I Hurler phenotype [MPS I-H]), even after successful hematopoietic stem cell transplantation (HSCT). One of the hallmarks of dysostosis multiplex in MPS I-H is hip dysplasia, which often requires surgical intervention. We sought to describe in detail the course of hip dysplasia in this group of patients, as assessed by radiographic analysis, and to identify potential outcome predictors. METHODS: Longitudinal data were obtained from digitally scored pelvic radiographs of patients with MPS I-H using OrthoGon software for parameters including, but not limited to, the acetabular index, migration percentage, Smith ratio, and neck-shaft angle. Scoring was performed independently by two blinded observers. Additional information on genotype, enzyme replacement therapy pre-HSCT, donor chimerism, and enzyme activity post-HSCT were obtained. General trends and potential correlations were calculated with mixed-model statistics. RESULTS: Fifty-two patients (192 radiographs) were included in this analysis. Intraobserver and interobserver variation analysis showed an intraclass correlation coefficient ranging from 0.78 to 1.00. Among the twenty-one patients with follow-up beyond the age of five years, the acetabular index was in the range of severe hip dysplasia in up to 86% of the patients. Severe coxa valga was seen in 91% of the patients. Lateral and superior femoral displacement were highly prevalent, with the migration percentage outside the reference range in up to 96% of the patients. Finally, anterior pelvic tilt increased with age (p = 0.001). No correlations were identified between clinical parameters and radiographic findings. CONCLUSIONS: Our study shows that progressive acetabular dysplasia as well as coxa valga and hip displacement are highly prevalent and progressive over time in patients with MPS I-H, despite successful HSCT. These data may provide essential natural history determinations for the assessment of efficacy of new therapeutic strategies aimed at improving skeletal outcomes in patients with MPS I-H.

Pharmacokinetically guided dosing of carboplatin in paediatric cancer patients with bilateral nephrectomy.

An approach to carboplatin dosing in children with bilateral nephrectomy using a renal function-based dosing formula with a glomerular filtration rate of zero was investigated in the current study. Carboplatin exposure was determined in a total of nine courses of chemotherapy in four patients with Wilms' tumour. Carboplatin exposures following initial dosing were less than 50% of the defined target area under the plasma concentration-time curve (AUC) in all four patients studied, with actual AUC values of between 31% and 45% of the target exposures. The use of real-time pharmacokinetic monitoring to guide dosing within a course of carboplatin treatment resulted in exposures within 15% of the target AUC in all patients. Using this information to guide dosing on additional courses of treatment in the same patient resulted in consistent exposures without the need for further monitoring or dose adjustment. These results indicate that real-time pharmacokinetic monitoring of carboplatin treatment plays a key role in ensuring that an appropriate exposure to carboplatin is achieved in children with bilateral nephrectomy. Carboplatin dosing based on patient body weight, or use of a fixed dose of carboplatin, would both be predicted to result in individual patients receiving unsatisfactory drug exposures. Further studies are warranted to further elucidate the relationship between non-renal clearance of carboplatin and patient body weight in this and other patient subpopulations where there remains concern about the optimal way to use this anticancer drug.

The novel pyrrolo-1,5-benzoxazepine, PBOX-6, synergistically enhances the apoptotic effects of carboplatin in drug sensitive and multidrug resistant neuroblastoma cells.

Neuroblastoma, a malignancy of neuroectoderrmal origin, accounts for 15% of childhood cancer deaths. Despite advances in understanding the biology, it remains one of the most difficult paediatric cancers to treat. A major obstacle in the effective treatment of neuroblastoma is the development of multidrug resistance (MDR). There is thus a compelling demand for new treatment strategies for this cancer that can bypass such resistance mechanisms. The pyrrolo-1,5-benzoxazepine (PBOX) compounds are a series of novel microtubule-targeting agents that potently induce apoptosis in various cancer cell lines, ex vivo patient samples and in vivo cancer models. In this study we examined the ability of two members, PBOX-6 and -15, to exhibit anti-cancer effects in a panel of drug sensitive and MDR neuroblastoma cell lines. The PBOX compounds potently reduced the viability of all neuroblastoma cells examined and exhibited a lower fold resistance in MDR cells when compared to standard chemotherapeutics. In addition, the PBOX compounds synergistically enhanced apoptosis induced by etoposide, carboplatin and doxorubicin. Exposure of drug sensitive and resistant cell lines to PBOX-6/carboplatin induced cleavage of Bcl-2, a downregulation of Mcl-1 and a concomitant increase in Bak. Furthermore, activation of caspase-3, -8 and -9 was demonstrated. Finally, gene silencing of Mcl-1 by siRNA was shown to sensitise both drug sensitive and multidrug resistant cells to carboplatin-induced apoptosis demonstrating the importance of Mcl-1 downregulation in the apoptotic pathway mediated by the PBOX compounds in neuroblastoma. In conclusion, our findings indicate the potential of the PBOX compounds in enhancing chemosensitivity in neuroblastoma.