Ulrik Lausten-Thomsen

Prevalence of t(12;21)[ETV6-RUNX1]-positive cells in healthy neonates.

t(12;21)(p13;q22)[ETV6-RUNX1] is the most common chromosomal translocation in childhood acute lymphoblastic leukemia, and it can often be backtracked to Guthrie cards supporting prenatal initiation and high levels of circulating t(12;21)-positive cells at birth. To explore the prevalence of ETV6-RUNX1-positive cells in healthy neonates, mononuclear cells from 1417 umbilical cord blood samples were isolated within 24 hours from birth and subsequently screened for ETV6-RUNX1 transcripts using a highly sensitive real-time reverse transcription polymerase chain reaction assay. In first-run polymerase chain reaction, 14 samples were positive at levels below 10(-5), of which specific hybridization reflecting the relevant genetic region was positive in 9 cases. Repeated analyses using stored mRNA and flowcytometric sorting of a CD19(+), CD8(+), and CD19(-)/CD8(-) subpopulations from cryopreserved mononuclear cells from the same cord blood samples (mean sorted: 18 × 10(6) cells) revealed no positive findings, which demonstrates that the level and/or frequency of ETV6-RUNX1-positive cells is markedly lower than suggested in previous studies.

Inflammatory Markers in Umbilical Cord Blood from Small-For-Gestational-Age Newborns

This study investigates the role of inflammation in intrauterine growth retardation by exploring the levels of inflammatory markers in umbilical cord blood from neonates who were born small-for-gestational-age (SGA) and comparing them to neonates who were born appropriate-for-gestational-age (AGA). Interleukin 6 (IL-6), Tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were measured by standard methods in term or near-term (gestational age >36 weeks) neonates born SGA (n = 45) and a matched group of neonates born AGA (n = 45). Infants exposed to maternal chronic diseases, diabetes or pre-eclampsia were excluded. SGA was defined as two standard derivations below the expected for term and gender. In multivariate regression analyses significant elevation in cord blood concentration of IL-6 was demonstrated in the SGA group (mean 4.56 vs. 2.38, p = 0.002). The results indicate the presence of elevated inflammatory markers in the cord blood from SGA infants compared to AGA infants, and consequently the results suggest an inflammatory component in intrauterine growth restriction (IUGR).

Duration of adrenal insufficiency during treatment for childhood acute lymphoblastic leukemia.

Children with acute lymphoblastic leukemia (ALL) recive high doses of glucocorticosteroid as part of their treatment. This may lead to suppression of the hypothalamic-pituitary-adrenal axis, acute adrenal insufficiency, and ultimately to life-threatening conditions. This study explores the adrenal function in 96 children with ALL treated according to common protocols. After cessation of induction glucocorticosteroid therapy, they received hydrocortisone substitution therapy (10 mg/m2/24 h) until an adrenocorticotropic hormone test (250 &mgr;g tetracosatide) showed a sufficient adrenal response [plasma (p)-cortisol ≥500 nM]. At the first adrenocorticotropic hormone test, 67% of the patients had adrenal insufficiency. When including these patients in a multivariate model, not adjusting for risk factors, the mean elapsed time between end of induction therapy and adrenal sufficiency was 8.5 months (95% confidence interval: 6.3;10.7). Low 0-minute p-cortisol (P=0.02) and low rise in p-cortisol (P<0.0001) at first test caused a longer time of adrenal insufficiency. In addition, patients with B-cell precursor leukemia reached adrenal sufficiency later than those with T-cell leukemia (P=0.067). As adrenal insufficiency is frequent in children treated for ALL and as they often experience infections and other stressors, the adrenal response should be determined and hydrocortisone substitution therapy should be considered during such episodes in patients with adrenal insufficiency.

Increased risk of ALL among premature infants is not explained by increased prevalence of pre-leukemic cell clones

The multi-hit hypothesis for paediatric leukemogenesis states that an initial genetic hit (often occurring prenataly) must be followed by one or more hit(s) before a cell become leukeamic. Studies have demonstrated the presence of pre-leukaemic t(12;21)-positive cells at levels 10(-3) to 10(-4) in 1% of newborns (i.e. 100-fold their risk of t(12;21)-positive ALL), but only at levels of 10(-5) to 10(-6) in 0.5% adults. As the risk of developing ALL is inversely associated to the gestational age at birth, we investigated if this increased risk could be explained by an increase in prevalence and quantity of pre-leukaemic t(12;21)-positive children born prematurely. Using a sensitive qRT-PCR assay, we screened messenger RNA from fresh umbilical cord-blood samples from 256 premature children. In none of the neonates, t(12;21)-positive cells could be demonstrated. Therefore, no increase in the prevalence and magnitude of preleukaemic t(12;21)-positive cells compared to previously published data from mature children could be demonstrated. This indirectly supports the theory that prevalence and quantity of preleukaemic t(12;21)-positive cells peaks at term or early childhood and that exogenous factors are necessary to initiate their clearance.

Reference values for serum total adiponectin in healthy non-obese children and adolescents.

BACKGROUND Adiponectin is an abundant adipocyte-secreted hormone that modulates a number of metabolic processes and is correlated to various metabolic disorders. Pediatric reference levels are needed for the risk stratification and interpretation of individual serum adiponectin levels. METHODS A total of 1193 healthy, non-obese Danish schoolchildren (730 girls, 463 boys) aged 6-18 years (median 11.9) were examined by trained medical staff. Total serum adiponectin concentrations in venous fasting blood samples were quantitated by a DuoSet® ELISA human Adiponectin/Acrp30 (R&D Systems) following optimization. RESULTS In a generalized linear model adjusted for BMI SDS, total serum adiponectin concentrations were correlated to age in girls (p<0.0001) and boys (p=<0.0001) and for both sexes combined (p<0.0001). No significant difference between sexes was found. Reference intervals were calculated using age as a continuous variable. The best fitted reference curve for both sexes was: 50th percentile: Y=-0.1478 ∗ X+6.046; 2.5th percentile: Y=-0.06256 ∗ X+2.34; 97.5th percentile: Y=-0.4086 ∗ X+22.39, where Y=adiponectin in μg/mL and X=years of age (from 6 to 18 years). CONCLUSION We developed a pediatric reference levels for total serum adiponectin in a sample of 1193 Danish children and adolescents aged 6-18 years. A correlation with age was demonstrated in children, but no significant difference was seen between the sexes.

Adipokines in umbilical cord blood from children born large for gestational age.

Abstract Background: The etiology of childhood obesity and the associated morbidity is multifactorial. Recently, data suggesting a prenatal programming towards later childhood obesity and metabolic deregulation through the intrauterine environment has emerged. This study explored the concentrations of adipokines and their mutual relationship at birth in children born to non-diabetic mothers. Methods: Adiponectin, leptin and sOB-R were measured using ELISA-based commercial kits in umbilical cord blood from 60 neonates (30 born large for gestational age [LGA] and 30 born appropriate for gestational age [AGA]). Children exposed to maternal diabetes, chronic disease and preeclampsia were excluded. Results: The LGA group exhibited significantly elevated concentrations of leptin (p<0.001) and of free leptin index (p<0.001) and decreased sOB-R concentrations (p=0.005) when compared to the AGA group, which persisted in multiple regression analysis after taking the gestational age into account (p=0.048, p<0.001 and p<0.001, respectively). Only a trend towards a difference in adiponectin was demonstrated (p=0.057) regardless of adjustment (p=0.150). However, the leptin/adiponectin ratio was elevated in the LGA group (p=0.008), regardless of adjustment (p=0.039). Conclusion: The data indicate a disturbance of adipokines in macrosomic newborns and that the mutual ratios between adipokines may provide a more sensitive marker of metabolic disturbance than any isolated adipokine.

Reference values for serum leptin in healthy non-obese children and adolescents

Abstract Background: Adipokines are biologically active, low-molecular weight peptides, which play a major role in metabolic homeostasis in humans. Leptin has gained increasing attention in pediatrics as a biomarker for various metabolic pathologies. Yet, its usefulness is hampered by the relative lack of reference values from pediatric settings. Accordingly, this study aims to evaluate serum concentrations of leptin, soluble leptin receptor (sOB-R), and free leptin index (FLI) in healthy Danish schoolchildren aged 6–18 years and subsequently to establish reference intervals across sex and age groups. Methods: A total of 1193 healthy, non-obese Danish schoolchildren (730 girls, 463 boys) aged 6–18 years (median 11.9) were examined by trained medical staff. Serum leptin and sOB-R concentrations in venous fasting blood samples were quantitated by immunoassay. Percentile curves of leptin, sOB-R, and free leptin index were calculated using the General Additive Model for Location Scale and Shape (GAMLSS). Results: Significant age and sex-dependent differences in circulating leptin levels were found. In boys, the median leptin concentration for all ages combined was 3.35 μg/L (95%-interval: 0.71–22.47) and in girls, it was 9.89 ng/L (95%-interval: 2.06–41.49). For SOB-R, no sex-specific difference was found, and the median sOB-R concentration was 8.24 μg/L (IQR: 3.58–23.74; range: < 1.56–744.15). Conclusion: We demonstrated an age-dependent correlation with both serum leptin concentration and free leptin index with a gradual and significant increase in girls throughout childhood and adolescence and a significantly higher leptin concentration and free leptin index bell-shaped peak in early adolescence in boys.

Reference values for fasting serum resistin in healthy children and adolescents

BACKGROUND Resistin is a hormone, mainly produced in macrophages and monocytes, believed to play an important role in the inflammatory response. It has been linked to several chronic diseases such as heart failure, inflammatory bowel disease, and insulin resistance. Pediatric reference levels are needed for the risk stratification and interpretation of individual serum resistin concentrations. METHODS A total of 1191 healthy, non-obese Danish schoolchildren (727 girls) aged 6-18years (median 11.9) were included. Fasting serum resistin concentrations were quantitated by Human Resistin ELISA Development kit, Duo Set (R&D Systems) following optimization. RESULTS The overall median resistin concentration was 8.93ng/mL (interquartile range (IQR): 6.19-13.33, range 1.57-35.84) in boys and 10.42ng/mL (IQR: 7.25-15.68, range 1.60-44.00) in girls. The resistin concentration correlated to relative BMI in both boys (p=0.02) and girls (p<0.0001). Percentiles for each age group were calculated alongside smoothed percentile curves and an age correlated increase was demonstrated, albeit only in girls (p=0.02) and not in boys (p=0.35). CONCLUSION Fasting serum resistin concentrations differ between sexes in healthy children and adolescents and are correlated both with the sex- and age adjusted BMI, and in girls to age.

Dating of Pregnancy in First versus Second Trimester in Relation to Post-Term Birth Rate: A Cohort Study

Objectives To evaluate in a national standardised setting whether the performance of ultrasound dating during the first rather than the second trimester of pregnancy had consequences regarding the definition of pre- and post-term birth rates. Methods A cohort study of 8,551 singleton pregnancies with spontaneous delivery was performed from 2006 to 2012 at Copenhagen University Hospital, Holbæk, Denmark. We determined the duration of pregnancy calculated by last menstrual period, crown rump length (CRL), biparietal diameter (1st trimester), BPD (2nd trimester), and head circumference and compared mean and median durations, the mean differences, the systematic discrepancies, and the percentages of pre-term and post-term pregnancies in relation to each method. The primary outcomes were post-term and pre-term birth rates defined by different dating methods. Results The change from use of second to first trimester measurements for dating was associated with a significant increase in the rate of post-term deliveries from 2.1–2.9% and a significant decrease in the rate of pre-term deliveries from 5.4–4.6% caused by systematic discrepancies. Thereby 25.1% would pass 41 weeks when GA is defined by CRL and 17.3% when BPD (2nd trimester) is used. Calibration for these discrepancies resulted in a lower post-term birth rate, from 3.1–1.4%, when first compared to second trimester dating was used. Conclusions Systematic discrepancies were identified when biometric formulas were used to determine duration of pregnancy. This should be corrected in clinical practice to avoid an overestimation of post-term birth and unnecessary inductions when first trimester formulas are used.

Longitudinal changes in C-reactive protein, proform of eosinophil major basic protein, and pregnancy-associated plasma protein-A during weight changes in obese children

Abstract Background: Childhood obesity is associated with several complications, including cardiovascular comorbidity. Several biomarkers, such as high-sensitive C-reactive protein (hs-CRP), proform of eosinophil major basic protein (Pro-MBP) and pregnancy associated plasma protein-A (PAPP-A), have equally been linked to increased cardiovascular susceptibility. This study investigates these biomarkers during weight loss and regain in obese children. Materials and methods: A longitudinal study during a 12-week weight loss program with a 28 months follow-up was conducted. Anthropometrics and plasma concentrations of hs-CRP, Pro-MBP, and PAPP-A were measured at baseline; at days 14, 33 and 82 during weight loss; and at months 10, 16, and 28 during follow-up. Results: Fifty-three boys and 62 girls aged 8–15 years with a median body mass index (BMI) standard deviation score (SDS) at baseline of 2.78 (boys), and 2.70 (girls) were included. Ninety children completed the weight loss program and 68 children entered the follow-up program. Pro-MBP and PAPP-A, but not hs-CRP, exhibited individual-specific levels (tracking) during weight loss and regain. The PAPP-A/Pro-MBP correlation was strong, whereas the hs-CRP/PAPP-A correlation was weak during weight fluctuations. Conclusion: Hs-CRP changes reflect weight changes. PAPP-A and Pro-MBP exhibited tracking during weight perturbations and may contribute as early risk markers of cardiovascular susceptibility.