Prediction of Bloodstream Infection in Pediatric Acute Leukemia by Microbiota and Volatile Organic Compounds Analysis.

INTRODUCTION: Bloodstream infections (BSIs) cause treatment-related mortality in pediatric acute leukemia. We explored the potential of intestinal microbiota and fecal volatile organic compounds (VOCs) analyses to predict BSI. METHODS: In this case-control study, fecal samples of pediatric acute leukemia patients were collected. Microbiota composition and fecal VOC profiles of BSI cases and matched non-BSI controls were compared. RESULTS: In total, 6 patients were included, of which 1 developed BSI and 1 neutropenic fever. Both showed reduced microbial diversity and stability of Bacteroidetes. In the BSI case, Pantoea was identified 15 days before BSI. Significant differences in fecal VOC profiles were measured between the case and controls. CONCLUSION: Microbiota and fecal VOC could serve as biomarkers to predict BSI in pediatric leukemia.

Molecular Drug Imaging: 89Zr-Bevacizumab PET in Children with Diffuse Intrinsic Pontine Glioma.

Predictive tools for guiding therapy in children with brain tumors are urgently needed. In this first molecular drug imaging study in children, we investigated whether bevacizumab can reach tumors in children with diffuse intrinsic pontine glioma (DIPG) by measuring the tumor uptake of 89Zr-labeled bevacizumab by PET. In addition, we evaluated the safety of the procedure in children and determined the optimal time for imaging. Methods: Patients received 89Zr-bevacizumab (0.1 mg/kg; 0.9 MBq/kg) at least 2 wk after completing radiotherapy. Whole-body PET/CT scans were obtained 1, 72, and 144 h after injection. All patients underwent contrast (gadolinium)-enhanced MRI. The biodistribution of 89Zr-bevacizumab was quantified as SUVs. Results: Seven DIPG patients (4 boys; 6-17 y old) were scanned without anesthesia. No adverse events occurred. Five of 7 primary tumors showed focal 89Zr-bevacizumab uptake (SUVs at 144 h after injection were 1.0-6.7), whereas no significant uptake was seen in the healthy brain. In 1 patient, multiple metastases all showed positive PET results. We observed inter- and intratumoral heterogeneity of uptake, and 89Zr-bevacizumab uptake was present predominantly (in 4/5 patients) within MRI contrast-enhanced areas, although 89Zr-bevacizumab uptake in these areas was variable. Tumor targeting results were quantitatively similar at 72 and 144 h after injection, but tumor-to-blood-pool SUV ratios increased with time after injection (P = 0.045). The mean effective dose per patient was 0.9 mSv/MBq (SD, 0.3 mSv/MBq). Conclusion:89Zr-bevacizumab PET studies are feasible in children with DIPG. The data suggest considerable heterogeneity in drug delivery among patients and within DIPG tumors and a positive, but not 1:1, correlation between MRI contrast enhancement and 89Zr-bevacizumab uptake. The optimal time for scanning is 144 h after injection. Tumor 89Zr-bevacizumab accumulation assessed by PET scanning may help in the selection of patients with the greatest chance of benefit from bevacizumab treatment.

Kaposiform (spindle cell) hemangioendotelioma in a child with an unusual presentation.

We describe a male child with multifocal kaposiform hemangioendothelioma in the right and left cervical region with development of Kasabach-Merritt syndrome. Treatment with interferon-alpha resulted in a good but only temporary clinical response.He relapsed 3 times with regrowth of the right cervical tumor. Involvement of the liver is suspected, because normalization of the liver size followed after the treatment with interferon-alpha. The question remains whether the multiple osteolytic bone lesions also reflect kaposiform hemangioendothelioma localization.

Effect of dexamethasone on quality of life in children with acute lymphoblastic leukaemia: a prospective observational study.

BACKGROUND: Glucocorticoids are important in the treatment of childhood acute lymphoblastic leukaemia (ALL). However, cyclic administration of high dose glucocorticoids may cause rapid and substantial changes in quality of life (QoL). The maintenance phase of the Dutch ALL-9 protocol consisted of alternating two weeks on and five weeks off dexamethasone (6 mg/m(2)/day). The present study was performed to assess the effect of dexamethasone on QoL during treatment for ALL according to this protocol. METHODS: In a multicentre prospective cohort study, QoL was assessed halfway (T1) and at the end of the two-year treatment (T2). A generic (Child Health Questionnaire) and disease specific (PedsQL cancer version) QoL questionnaire were used to assess QoL in two periods: on and off dexamethasone, respectively. RESULTS: 41 children (56% males) were evaluated, mean age at diagnosis was 5.6 years. The CHQ physical and psychosocial summary scores were significantly lower than population norms. At T1 and T2, overall QoL showed no significant change. However, regarding specific domains (pain, cognitive functioning, emotion/behaviour and physical functioning) QoL decreased over time. QoL was significantly more impaired during periods on dexamethasone. CONCLUSION: Dexamethasone was associated with decreased QoL. At the end of treatment, reported QoL during dexamethasone deteriorated even more on certain scales (pain, cognitive functioning, emotion/behaviour and physical functioning). Knowledge of the specific aspects of QoL is essential to improve counselling and coping in paediatric oncology. Adverse effects of specific drugs on QoL should be taken into account when designing treatment protocols.

Is aggressive local treatment necessary for diffuse liver involvement in patients with progression of stage 4s neuroblastoma to stage 4?

Three patients with stage 4S neuroblastoma without MYC-N amplification who progressed to stage 4 with persistent liver involvement, were treated with iodine 131-meta-iodobenzylguanidine therapy, chemotherapy, and surgery. Successive histologic examination of the liver showed differentiation of the tumor in 2 patients and fibrosis in the third. One patient died of brain metastases at the age of 30 months. The other 2 patients are alive at 50 and 44 months. Diffuse liver involvement in patients with stage 4 progression of previous stage 4S without MYC-N amplification may differentiate after treatment. The aim of this report is to draw attention to major liver surgery that it may not be necessary in tumors without MYC-N amplification, despite the persistence of lesions in the liver.

A comparison of the in vitro cytotoxicity of daunorubicin and liposomal daunorubicin in pediatric acute leukemia.

Anthracyclines are effective in the treatment of leukemia, but their use is limited because of cardiotoxicity. Liposomal daunorubicin (L-DNR) is potentially less cardiotoxic than daunorubicin (DNR). We compared in vitro cytotoxicity in pediatric acute leukemia samples and found no significant differences between cytotoxicity of DNR and L-DNR.

Effect of polymorphisms in folate-related genes on in vitro methotrexate sensitivity in pediatric acute lymphoblastic leukemia.

We studied whether common polymorphisms in genes involved in folate metabolism affect methotrexate (MTX) sensitivity. Ex vivo MTX sensitivity of lymphoblasts obtained from pediatric patients with acute lymphoblastic leukemia (ALL; n = 157) was determined by the in situ thymidylate synthase inhibition assay after either continuous (21 hours; TSI(50, cont)) or short-term (3 hours; TSI(50, short)) MTX exposure. DNA was isolated from lymphoblasts obtained from cytospin slides. Polymorphisms in methylenetetrahydrofolate reductase (MTHFR 677C>T, MTHFR 1298A>C), methionine synthase (MTR 2756A>G), methionine synthase reductase (MTRR 66A>G), methylenetetrahydrofolate dehydrogenase (MTHFD1 1958G>A), serine hydroxymethyl transferase (SHMT1 1420C>T), thymidylate synthase (TS 2R3R), and the reduced folate carrier (RFC 80G>A) were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or real-time PCR. Patients with the MTHFR 1298AC variant or the MTRR 66 G-allele showed decreased in vitro MTX sensitivity measured under both test conditions. SHMT1 1420TT homozygotes only showed decreased MTX sensitivity in the TSI(50, cont). In conclusion, polymorphisms in the folate-related genes MTHFR, MTRR, and SHMT1 are related to MTX resistance in pediatric patients with ALL.

Reduced folate carrier mutations are not the mechanism underlying methotrexate resistance in childhood acute lymphoblastic leukemia.

BACKGROUND: Although the majority of children with acute lymphoblastic leukemia (ALL) are cured with combination chemotherapy containing methotrexate (MTX), drug resistance contributes to treatment failure for a substantial fraction of patients. The primary transporter for folates and MTX is the reduced folate carrier (RFC). Impaired drug transport is a documented mechanism of MTX resistance in patients with ALL; however, to the authors' knowledge it is not known whether inactivating RFC mutations are a contributing factor. METHODS: The authors devised a genomic polymerase chain reaction-single strand conformational polymorphism assay followed by sequencing and screened the entire RFC coding region for sequence alterations in DNA from 246 leukemia specimens from patients with diverse ethnic variation, 24 at the time of recurrence and the rest at the time of diagnosis. This cohort was comprised of 203 B-precursor ALL specimens (82.5%), 32 T-lineage ALL specimens (13%), and 11 acute myeloblastic leukemia specimens (4.5%). RESULTS: Of 246 DNA samples, only 3 diagnosis B-precursor ALL specimens (1.2%) were found to harbor alterations in the RFC gene, including heterozygous single nucleotide changes resulting in D56H and D522N substitutions in the first extracellular loop and the C-terminus of this transporter, respectively. The third sample had a sequence alteration in exon 3 that could not be identified because of the lack of availability of DNA. CONCLUSIONS: Whereas inactivating RFC mutations are a frequent mechanism of MTX resistance in human leukemia cell lines and in patients with osteosarcoma, they are not common and do not appear to play any significant role in intrinsic or acquired resistance to MTX in childhood leukemia. This is the first study of RFC mutations in multiple pediatric leukemia specimens.