Serum Of Pediatric Patients Research Articles

A Perspective Study on Therapeutic Drug Monitoring of Voriconazole in Pediatric Patients with Hematologic Disorders

Background: The incidence of invasive aspergillosis and the administration of voriconazole have risen among immunocompromised patients. Objectives: This study aimed to evaluate serum voriconazole concentration and its corresponding influential factors in pediatric patients with hematologic disorders. Methods: A total of 132 blood samples were collected from 44 pediatric patients with hematologic disorders infected with invasive aspergillosis and treated with voriconazole. Among these patients, 20.5% were classified as having proven invasive aspergillosis, 77.2% as probable, and 2.3% as possible. Voriconazole serum levels were evaluated using HPLC on the 3rd, 5th, and 7th days of treatment. Genotyping of the CYP2C19 alleles (*2, *3, and *17) was performed, and demographic and clinical data were gathered from records between 2018 to 2020. Results: The voriconazole concentration in 70.5% of patients and 77.3% of treatment cases (complete or partial) ranged from 1 to 5.5 µg/mL. Adverse events were observed in 4.5% of the patients. Genotyping of CYP2C19 genes revealed CYP2C19*1*1 (5.4%), CYP2C19*1*17 (16.2%), CYP2C19*1*2 (51.4%), and CYP2C19*2*17 (27%). Multivariate analysis using linear regression demonstrated that serum voriconazole concentration increased by 0.037 µg/mL per year of age and by 0.06 µg/mL for each unit increase in C-reactive protein (on the 3rd day of voriconazole therapy). Additionally, an increase in alanine aminotransferase level by 1 unit decreased the mean voriconazole concentration by 0.03 µg/mL. Of these patients, 65.9% were completely treated, 11.4% were partially treated, and 22.7% died. Conclusions: Serum voriconazole concentrations varied among pediatric hematologic patients receiving standard doses, with age, C-reactive protein, and alanine aminotransferase levels affecting the concentration of voriconazole in the sera of pediatric patients.

Analysis of Sphingolipids in Pediatric Patients with Cholelithiasis-A Preliminary Study.

(1) Background: Disturbances in the sphingolipid profile are observed in many diseases. There are currently no data available on the evaluation of sphingolipids and ceramides in cholelithiasis in children. The aim of this study was to evaluate the concentrations of sphingolipids in the sera of pediatric patients with gallstones. We determined their relationship with anthropometric and biochemical parameters. (2) Methods: The concentrations of sphingolipids in serum samples were evaluated using a quantitative method, ultra-high-performance liquid chromatography–tandem mass spectrometry. (3) Results: The prospective study included 48 children and adolescents diagnosed with gallstones and 38 controls. Serum concentrations of total cholesterol (TC); sphinganine (SPA); ceramides—C14:0-Cer, C16:0-Cer, C18:1-Cer, C18:0-Cer, C20:0-Cer and C24:1-Cer; and lactosylceramides—C16:0-LacCer, C18:0-LacCer, C18:1-LacCer, C24:0-LacCer and C24:1-LacCer differed significantly between patients with cholelithiasis and without cholelithiasis. After adjusting for age, gender, obesity and TC and TG levels, we found the best differentiating sphingolipids for cholelithiasis in the form of decreased SPA, C14:0-Cer, C16:0-Cer, C24:1-LacCer and C24:0-LacCer concentration and increased C20:0-Cer, C24:1-Cer, C16:0-LacCer and C18:1-LacCer. The highest area under the curve (AUC), specificity and sensitivity were determined for C16:0-Cer with cholelithiasis diagnosis. (4) Conclusions: Our results suggest that serum sphingolipids may be potential biomarkers in pediatric patients with cholelithiasis.

Elevated Biomarkers of NETosis in the Serum of Pediatric Patients With Type 1 Diabetes and Their First-Degree Relatives.

Type 1 diabetes (T1D) is an autoimmune disorder with unambiguous involvement of both innate and adaptive immune mechanisms in the destruction of pancreatic beta cells. Recent evidence demonstrated that neutrophils infiltrate the pancreas prior to disease onset and therein extrude neutrophil extracellular traps (NETs), web-like structures of DNA and nuclear proteins with a strong pro-inflammatory biologic activity. Our previous work showed that T1D NETs activate dendritic cells, which consequently induce IFNγ-producing Th1 lymphocytes. The aim of this study was to assess direct ex vivo biomarkers of NETosis in the serum of recent onset and long-term pediatric T1D patients, their first-degree relatives and healthy controls. To this end we evaluated serum levels of myeloperoxidase (MPO), neutrophil elastase (NE), proteinase 3 (PR3), protein arginine deiminase 4 (PAD4), LL37 and cell-free DNA-histone complexes in sex- and age-matched cohorts of T1D first-degree relatives, recent-onset T1D patients, and in patients 12 months after clinical manifestation of the disease. Our data shows that disease onset is accompanied by peripheral neutrophilia and significant elevation of MPO, NE, PR3, PAD4 and cell-free DNA-histone complexes. Most biomarkers subsequently decrease but do not always normalize in long-term patients. First-degree relatives displayed an intermediate phenotype, except for remarkably high levels of LL37. Together, this report provides evidence for the presence of ongoing NETosis in pediatric patients with T1D at time of clinical manifestation of the disease, which partly subsides in subsequent years.

Diagnostic Performance of (1→3)-β-D-Glucan Alone and in Combination with Aspergillus PCR and Galactomannan in Serum of Pediatric Patients after Allogeneic Hematopoietic Stem Cell Transplantation.

Data on biomarker-assisted diagnosis of invasive aspergillosis (IA) in pediatric patients is scarce. Therefore, we conducted a cohort study over two years including 404 serum specimens of 26 pediatric patients after allogeneic hematopoietic stem cell transplantation (alloSCT). Sera were tested prospectively twice weekly for Aspergillus-specific DNA, galactomannan (GM), and retrospectively for (1→3)-β-D-glucan (BDG). Three probable IA and two possible invasive fungal disease (IFD) cases were identified using the European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSGERC) 2019 consensus definitions. Sensitivity and specificity for diagnosis of probable IA and possible IFD was 80% (95% confidential interval (CI): 28–99%) and 55% (95% CI: 32–77%) for BDG, 40% (95% CI: 5–85%) and 100% (95% CI: 83–100%) for GM, and 60% (95% CI: 15–95%) and 95% (95% CI: 75–100%) for Aspergillus-specific real-time PCR. However, sensitivities have to be interpreted with great caution due to the limited number of IA cases. Interestingly, the low specificity of BDG was largely caused by false-positive BDG results that clustered around the date of alloSCT. The following strategies were able to increase BDG specificity: two consecutive positive BDG tests for diagnosis (specificity 80% (95% CI: 56–94%)); using an optimized cutoff value of 306 pg/mL (specificity 90% (95% CI: 68–99%)) and testing BDG only after the acute posttransplant phase. In summary, BDG can help to diagnose IA in pediatric alloSCT recipients. However, due to the poor specificity either an increased cutoff value should be utilized or BDG results should be confirmed by an alternative Aspergillus assay.

Serum proteome-wide identified ATP citrate lyase as a novel informative diagnostic and prognostic biomarker in pediatric sepsis: A pilot study.

IntroductionATP citrate lyase (ACLY) is involved in lipid metabolism and inflammatory response in immune cells. However, the serum level of ACLY and its clinical relevance in sepsis is totally unknown.MethodsWe conducted a prospective pilot study in patients with sepsis admitted to pediatric intensive care unit (PICU) from January 2018 to December 2018.ResultsHigher levels of ACLY were detected in sera of pediatric patients with sepsis than that of healthy children. The area under the receiver operating characteristic curve (AUC) of ACLY for diagnosis of sepsis was 0.855 (95% confidence interval [CI]: 0757–0.952), and an AUC of ACLY for predicting PICU mortality was 0.770 (95% CI: 0.626–0.915). ACLY levels ≤21 ng/ml on PICU admission predicted an unfavorable prognosis among patients with sepsis with a sensitivity of 87.5% and a specificity of 67.6%. Moreover, serum ACLY levels were correlated to platelet count, IL‐18 levels, and monocyte counts in pediatric patients with sepsis, implying the potential roles of ACLY in immunometabolic regulation in sepsis.ConclusionsACLY is firstly identified in sera of patients with sepsis. Serum ACLY level is an additional diagnostic and prognostic biomarker in pediatric patients with sepsis.

Protein-conformational diseases in childhood: Naturally-occurring hIAPP amyloid-oligomers and early β-cell damage in obesity and diabetes.

Background and aimsThis is the first time that obesity and diabetes mellitus (DM) as protein conformational diseases (PCD) are reported in children and they are typically diagnosed too late, when β-cell damage is evident. Here we wanted to investigate the level of naturally-ocurring or real (not synthetic) oligomeric aggregates of the human islet amyloid polypeptide (hIAPP) that we called RIAO in sera of pediatric patients with obesity and diabetes. We aimed to reduce the gap between basic biomedical research, clinical practice-health decision making and to explore whether RIAO work as a potential biomarker of early β-cell damage.Materials and methodsWe performed a multicentric collaborative, cross-sectional, analytical, ambispective and blinded study; the RIAO from pretreated samples (PTS) of sera of 146 pediatric patients with obesity or DM and 16 healthy children, were isolated, measured by sound indirect ELISA with novel anti-hIAPP cytotoxic oligomers polyclonal antibody (MEX1). We carried out morphological and functional studied and cluster-clinical data driven analysis.ResultsWe demonstrated by western blot, Transmission Electron Microscopy and cell viability experiments that RIAO circulate in the blood and can be measured by ELISA; are elevated in serum of childhood obesity and diabetes; are neurotoxics and works as biomarkers of early β-cell failure. We explored the range of evidence-based medicine clusters that included the RIAO level, which allowed us to classify and stratify the obesity patients with high cardiometabolic risk.ConclusionsRIAO level increases as the number of complications rises; RIAOs > 3.35 μg/ml is a predictor of changes in the current indicators of β-cell damage. We proposed a novel physio-pathological pathway and shows that PCD affect not only elderly patients but also children. Here we reduced the gap between basic biomedical research, clinical practice and health decision making.

Dengue NS1 detection in pediatric serum using microfluidic paper-based analytical devices.

The diagnosis of dengue infection is still a critical factor determining success in the clinical management and treatment of patients. Here, the development of microfluidic paper-based analytical devices (μPADs) utilizing a sandwich immunoassay on wax patterned paper functionalized with anti-dengue NS1 monoclonal antibodies for point-of-care detection of dengue NS1 (DEN-NS1-PAD) is reported. Various assay conditions, including the length of the channel and diluent, were optimized, and the response detected by the naked eye and digitized images within 20-30min. The DEN-NS1-PAD was successfully tested in the field for detecting dengue NS1 in buffer, cell culture media, and human serum. The limit of detection (LoD) of the DEN-NS1-PAD obtained with the naked eye, scanner, and a smartphone camera was 200, 46.7, and 74.8ngmL-1, respectively. The repeatability, reproducibility, and stability of the DEN-NS1-PAD were also evaluated. High true specificity and sensitivity in the serum of pediatric patients were observed. These evaluation results confirm that the DEN-NS1-PAD can potentially be used in point-of-care dengue diagnostics, which can significantly impact on the spreading of mosquito-borne diseases, which are likely to become more prevalent with the effects of global warming. Graphical Abstract.

Unpacking the aggregation-oligomerization-fibrillization process of naturally-occurring hIAPP amyloid oligomers isolated directly from sera of children with obesity or diabetes mellitus

The formation of amyloid oligomers and fibrils of the human islet amyloid polypeptide (hIAPP) has been linked with β- cell failure and death which causes the onset, progression, and comorbidities of diabetes. We begin to unpack the aggregation-oligomerization-fibrillization process of these oligomers taken from sera of pediatric patients. The naturally occurring or real hIAPP (not synthetic) amyloid oligomers (RIAO) were successfully isolated, we demonstrated the presence of homo (dodecamers, hexamers, and trimers) and hetero-RIAO, as well as several biophysical characterizations which allow us to learn from the real phenomenon taking place. We found that the aggregation/oligomerization process is active in the sera and showed that it happens very fast. The RIAO can form fibers and react with anti-hIAPP and anti-amyloid oligomers antibodies. Our results opens the epistemic horizon and reveal real differences between the four groups (Controls vs obesity, T1DM or T2DM) accelerating the process of understanding and discovering novel and more efficient prevention, diagnostic, transmission and therapeutic pathways.

5991Circulating microRNA profiling in serum of pediatric patients with heart failure submitted to VAD implant

5991Circulating microRNA profiling in serum of pediatric patients with heart failure submitted to VAD implant

Acetaminophen Adducts Detected in Serum of Pediatric Patients With Acute Liver Failure.

Previous studies in patients with acute liver failure identified acetaminophen (APAP) protein adducts in the serum of 12% and 19% of children and adults, respectively, with acute liver failure of indeterminate etiology. This article details the testing of APAP adducts in a subset (n = 393) of patients with varied diagnoses in the Pediatric Acute Liver Failure Study Group (PALFSG). Serum samples were available from 393 participants included in the PALFSG registry. Adduct measurement was performed using validated methods. Participants were grouped by diagnostic category as known APAP overdose, known other diagnosis, and indeterminate etiology. Demographic and clinical characteristics and participant outcomes were compared by adduct status (positive or negative) within each group. APAP adduct testing was positive in 86% of participants with known APAP overdose, 6% with other known diagnoses, and 11% with an indeterminate cause of liver failure. Adduct-positive participants were noted to have marked elevation of serum alanine aminotransferase and aspartate aminotransferase coupled with total serum bilirubin that was significantly lower than adduct-negative patients. In the indeterminate group, adduct-positive patients had different outcomes than adduct-negative patients (P = 0.03); spontaneous survival was 16 of 21 (76%) in adduct-positive patients versus 75 of 169 (44%) in adduct-negative patients. Prognosis did not vary by adduct status in patients with known diagnoses. Furthermore, study is needed to understand the relation of APAP exposure, as determined by the presence of APAP adducts, to the clinical phenotype and outcomes of children with acute liver failure.

IgE anti-respiratory syncytial virus antibodies detected in serum of pediatric patients with asthma

Respiratory syncytial virus (RSV) causes lower respiratory tract disease in infants and young children, and is a public health concern, as is the increase in pediatric asthma. Respiratory viral infections may trigger asthma exacerbations. However, it remains unknown whether RSV infection may have a specific association with asthma. Total serum IgE, and IgE- and IgG-anti-RSV Ab responses were studied in older asthmatic compared with non-asthmatic children (M/F, mean age: 14) (N=30, N=43, respectively). We found: (1) total serum IgE was higher in asthmatic compared with non-asthmatics (P<0.001); (2) total serum IgE did correlate with IgE anti-RSV Abs (P<0.001), and with IgG anti-RSV Abs (P=0.008) in all subjects; (3) total serum IgE levels did correlate with IgE anti-RSV in asthmatics (P=0.047), but not in non-asthmatics (P=0.13); (4) IgE anti-RSV Abs did correlate with IgG anti-RSV Abs in all subjects (P=0.001); (5) IgE- and IgG-anti RSV Abs were higher in asthma compared with no asthma (P=0.003; <0.001, respectively); (6) there was a significant association between age and IgE anti-RSV in non-asthma (P=0.008), but not in asthma (P=0.64). Our findings indicate that IgE-anti-RSV Ab responses may play important roles in RSV infection and asthma.

Galactose-α-1,3-galactose and Delayed Anaphylaxis, Angioedema, and Urticaria in Children

Despite a thorough history and comprehensive testing, many children who present with recurrent symptoms consistent with allergic reactions elude diagnosis. Recent research has identified a novel cause for "idiopathic" allergic reactions; immunoglobulin E (IgE) antibody specific for the carbohydrate galactose-α-1,3-galactose (α-Gal) has been associated with delayed urticaria and anaphylaxis that occurs 3 to 6 hours after eating beef, pork, or lamb. We sought to determine whether IgE antibody to α-Gal was present in sera of pediatric patients who reported idiopathic anaphylaxis or urticaria. Patients aged 4 to 17 were enrolled in an institutional review board-approved protocol at the University of Virginia and private practice allergy offices in Lynchburg, VA. Sera was obtained and analyzed by ImmunoCAP for total IgE and specific IgE to α-Gal, beef, pork, cat epithelium and dander, Fel d 1, dog dander, and milk. Forty-five pediatric patients were identified who had both clinical histories supporting delayed anaphylaxis or urticaria to mammalian meat and IgE antibody specific for α-Gal. In addition, most of these cases had a history of tick bites within the past year, which itched and persisted. A novel form of anaphylaxis and urticaria that occurs 3 to 6 hours after eating mammalian meat is not uncommon among children in our area. Identification of these cases may not be straightforward and diagnosis is best confirmed by specific testing, which should certainly be considered for children living in the area where the Lone Star tick is common.

Low opsonic activity to the infecting serotype in pediatric patients with invasive pneumococcal disease

Serotype-specific protective immunity in pediatric patients with invasive pneumococcal disease (IPD) has not been fully investigated. To determine the protective immunity to the infecting serotype, the serotype-specific immunoglobulin G (IgG) levels and opsonization indices (OIs) were examined in 24 Japanese pediatric patients whose serum was collected within one month of an IPD episode between May 2008 and June 2011. The median age (range) of IPD patients was 17 (10–108) months and 63% were boys. In all 17 patients tested, the levels of serotype-specific IgG to the infecting serotype were higher than 0.2μg/ml, but the OIs to the infecting serotype were <8. The avidities of 19F- or 6B-specific IgG in patients with levels higher than 5.0μg/ml, but with undetectable OIs, were confirmed to be lower than those in patients with high OIs. Our data demonstrated that although the levels of serotype-specific IgG to the infecting serotype were higher than 0.2μg/ml in sera of pediatric patients with IPD, the OIs were low one month after the IPD episode. Low opsonic activities in these patients may, in part, be explained by the low avidity of serotype-specific IgG.

Circulating biomarker-IgM complexes in the serum of pediatric patients with osteosarcoma and Ewing tumor (127.9)

Abstract Osteosarcoma (OS) and Ewing tumor (ET) together account for the majority of musculoskeletal sarcomas diagnosed in patients of all ages and nearly 90% of those occurring in children and adolescents. Natural IgM antibodies to tumor antigen have been reported in patients with early-stage cancer, and a panel of serum antibodies can detect cancer many years prior to imaging detection. Circulating immune complexes formed by tumor antigens and immunoglobulin M (IgM) represent a novel class of biomarkers with diagnostic value for early cancer detection. In the present study, we investigated the presence of ANG-IgM, VEGF-IgM, bFGF-IgM, PDGF-IgM in the sera of children with bone tumors. The study included 174 pediatric patients with newly diagnosed bone tumors. Express ELISA techniques have been developed to quantify immune complexes in INR. Serum samples from all patients were analyzed for the presence of biomarker-IgM immune complexes. We compared the serum level of angiogenic factors and immune complexes in children with different types of bone tumors. The highest concentration of VEGF-IgM was detected in ET patients and ANG-IgM in OS patients. The present study demonstrated increased ANG-IgM expression in the sera OS patients and a positive correlation between its expression levels and tumor vascularity evaluated by CTA. Our results have potential applications as biomarkers for controlling unwanted angiogenesis, early diagnosis and response to therapy in children with bone tumors.

A soluble form of CTLA-4 is present in serum of pediatric patients with acute lymphoblastic leukaemia

A soluble form of CTLA-4 is present in serum of pediatric patients with acute lymphoblastic leukaemia

A soluble form of CTLA-4 is present in serum of pediatric patients with acute lymphoblastic leukaemia

CTLA-4 can regulate and maintain self-telerance, providing a negative signal limiting immunoresponses. Acute lymphoblastic leukemia is a clonal disorder of lymphoid progenitors representing the most frequent malignancy of childhood. Here, we show the presence of significantly elevated levels of a soluble form of CTLA-4 in 70% of B-ALL patients. A possible role of this soluble molecule in the pathogenesis of this neoplastic disease can be envisaged.

Protein Biomarkers in Serum of Pediatric Patients with Severe Traumatic Brain Injury Identified by ICAT–LC-MS/MS

This report is a feasibility study on the utility of gel-free proteomics in identifying peripheral biomarkers of brain injury. The study was performed in six pediatric patients admitted to the intensive care unit for severe traumatic brain injury (TBI). Serum samples collected at admission (less than 8 h after injury) were used for determining the levels of S100beta by enzyme-linked immunosorbent assay (ELISA) and for proteomics analyses. Serum samples were depleted of high abundant albumin and immunoglobulin, and were compared to a pooled reference from several healthy individuals. After labeling and separation on an ionic column, six different serum fractions were analyzed using Isotope-Coded Affinity Tag (ICAT), followed by tandem mass spectrometry (MS/MS) protein sequencing and identification. Ninety-five unique, differentially expressed proteins were identified, including several with a likely brain origin. Several proteins with pattern similarity to S100beta identified by hierarchical clustering could be considered for evaluation in a larger patient sample as potential peripheral markers of TBI.

Sensitive and convenient method for the quantification of clonidine in serum of pediatric patients using liquid chromatography/tandem mass spectrometry

An improved and easy to use liquid chromatography/tandem mass spectrometric (LC/MS/MS) method in human serum was developed for the quantification of clonidine (CLD), an alpha 2-/alpha 1-adrenoceptor agonist, used for analgo-sedation and the therapy of opioid withdrawal in pediatric patients. Sample preparation consisted of precipitation of serum proteins by adding acetonitrile and centrifugation of the sample subsequently. [ 2H 4]Clonidine (CLD4) served as internal standard. Chromatographic separation of the supernatant was achieved using a 100 mm × 3 mm, 5 μm Thermo Electron BetaBasic C4 column with isocratic flow and elution consisting of 0.1% formic acid/acetonitrile (85/15, v/v) and a flow-rate of 350 μl/min resulting in a column pressure of 280–420 kPa. LC/MS/MS detection was performed by using a triple-stage quadrupole mass spectrometer (TSQ Quantum, Thermo Electron) working in selected reaction monitoring mode with positive electrospray ionization. The analyte was quantified in a single run within 5 min. Linearity was demonstrated over the expected concentration range 0.15–50 μg/l CLD. The lower limit of quantification (LLOQ) and the limit of detection were 0.1 μg/l and 0.01 μg/l, respectively. None of the drugs used concomitantly during analgesic therapy interfered in the assay in vitro. Intra-day precision expressed as RSD was 9.6% or less for CLD, while inter-day result was 10.0% or less for CLD. Intra-day and inter-day accuracy was within ±4.9% and ±1.8%, respectively. The method was validated according to the international guidelines of the International Conference on Harmonisation (ICH) and the US Food and Drugs Administration (FDA). The described method is suitable to analyse serum samples with very small volumes and sets the stage for pharmacokinetic studies in pediatric studies.

Pharmacodynamic (PD) Analyses of Asparagine (Asn) Deamination and Asn Input (Imax) in Serum of Pediatric Patients with Standard Risk Acute Lymphoblastic Leukemia (SR ALL) Receiving Native or Pegylated E. Coli Asparaginases (ASNase) (CCG-1962).

Background. Asn depletion in the serum during ASNase treatment (Tx) causes the death of lymphoblasts that lack ability to synthesize Asn. The Asn serum levels during treatment depend on ASNase activity, the rate of clearance of the enzyme and the input rate of Asn into circulation from the liver and other organs (Imax). We developed a population pharmacokinetic & pharmacodynamic (PK-PD) model in NONMEM to estimate the input rate in the standard risk ALL patients (pts) treated on CCG-1962.Methods. We compared the Asn concentrations during induction determined by HPLC amino acid assay in 24 pts who subsequently relapsed and in all event-free (CCR) pts from CCG-1962 SR ALL study. A best fit population PK-PD model between ASNase and Asn concentrations was developed for each patient to estimate the maximum input rate, Imax, and its additive error correction factor. Six year event-free survival was correlated with Imax or additive error with Kaplan-Meier analyses.Results. Patients received either 2500 IU/m2 PEG-ASNase once or 6000 IU/m2 native ASNase x 9, intramuscularly, during induction. The deaminated Asn serum levels were superimposable in patients randomized to native or PEG-ASNase arm. The mean and SDEV for Imax and the additive error are shown in Table 1 for each enzyme preparation for patients in CCR and for those who later developed BM, CNS, or testicular relapses. Imax was significantly greater in the relapsed than in the CCR patients, in the PEG-ASNase (p=0.002) and in the native ASNase (p=0.005) arms.Table 1. Imax and additive error of Asn in relapsed and in continuous complete remission (CCR) patients - CCG-1962CCG-1962 ArmsPEG-ASNase arm, n=56PEG-ASNase arm, n=56Native ASNase arm, n=57Native ASNase arm, n=57PD ParametersImax*Additive error*Imax*Additive error*CCR patients9.93 E -6 ± 2.4 E -5**1.51 E -6 ± 2.86 E -62.92 E -5 ± 1.52 E -42.52 E -6 ± 6.61 E -6N46464343Relapsed8.9 E -3 ± 6.0 E -32.87 E -6 ± 3.1 E -64.51 E -3 ± 4.94 E -31.05 E -5 ± 1.76 E -5N10101414p, unequal variance t-testP=0.0021p=0.25p=0.0047p=0.118* nmoles/ml/min, ** All values are mean ± SDEVTable 2 shows the summary of the Kaplan-Meier analyses in all patients. Both the Imax and additive factor significantly correlate with relapse.Table 2. Summary of Kaplan - Meier analysesPatientsPEG-ASNase arm, n=56PEG-ASNase arm, n=56Native E.Coli-ASNase arm, n=57Native E.Coli-ASNase arm, n=57Parameter and cutoffImax < 0.001Imax > 0.001Imax < 0.001Imax > 0.001Events, Observed/Exp2/8.598/1.413/6.1411/7.86Total45112631Log-rank p value1.64 E -60.046Parameter and cutoffAdd rate < 1E -6Add rate > 1E -6Add rate < 1E -6Add rate > 1E -6Events, Observed/Exp1/5.639/4.375/10.369/3.64Total28283918Log-rank P value0.0020.0024Conclusions. The Asn levels after Tx are similar in both arms in pts with events and CCR. Nevertheless this PD model strongly suggests that the Imax of input of Asn in the circulation is faster in relapsed than in CCR patients. Furthermore, Imax and its additive rate are correlated with 6 year event free survival of SR ALL pts, independent of the ASNase formulation used in their Tx.

Novel tumor antigens identified by autologous antibody screening of childhood medulloblastoma cDNA libraries.

Medulloblastoma is an embryonal childhood malignancy with poor prognosis. By screening 4 medulloblastoma cDNA expression libraries (SEREX) with autologous sera, 15 different antigens were identified. These antigens were encoded by 3 novel genes, genes of unknown function (KIAA0445, KIAA1853, KIAA0665, FLJ13942, HSPC213), a proto-oncogene (rab18), candidate tumor suppressor genes (BAP1, PRDM13) and genes encoding a motor protein (kinesin-2), a histone (H2A1.2), the ankyrin residue-rich nasopharyngeal cancer susceptibility protein (NZ16) and the transcription factor TZP, which is homologous to the tumor-associated antigens HCA58 and GLEA2. In a consecutive analysis of serum antibody titers and tumor load, a more than 10-fold increase in serum antibodies against PRDM13 preceded the clinical diagnosis of recurrent tumor growth in a patient with aggressive large cell medulloblastoma. When sera of pediatric patients with cancer (n = 40) and healthy controls (n = 40) were tested for humoral responses against the SEREX-defined antigens, 5 antigens were exclusively recognized by sera from cancer patients. These antigens included a novel rab18 gene product translated from mRNA sequences formerly described as 3' untranslated region. Humoral responses against 2 of the remaining 10 antigens were found preferentially in cancer patients. Antibodies against these antigens were detected in 8/40 and 12/40 cancer patients, respectively, but in only 1 healthy control. The 2 antigens were characterized by a tumor-specific deletion and a tumor-specific mutation, respectively. These findings indicate that the humoral immune response against medulloblastoma is directed against diverse antigens that may be useful as diagnostic markers or targets for immunotherapy.