Thomas Eckhard Hundhausen

• Reiersøl, Elin Lovise Hallheim & Hundhausen, Thomas Eckhard (2024). Sammenligning av metoder for eluering av IgG-antistoff bundet til erytrocytter. Bioingeniøren. ISSN 0801-6828. Full text in Research Archive
• Osestad, Toril Margrethe; Lilleholt, Kristin; Skadberg, Øyvind; Sagedal, Linda Reme; Vistad, Ingvild & Hundhausen, Thomas Eckhard (2024). Glycated albumin in pregnancy correlates negatively with body mass index and contributes to the risk of gestational diabetes mellitus. Practical Laboratory Medicine. 42. doi: 10.1016/j.plabm.2024.e00439. Full text in Research Archive
• Wilson, Siobhan M.; Bohn, Mary Kathryn; Madsen, Andre Greger; Hundhausen, Thomas Eckhard & Adeli, Khosrow (2023). LMS-based continuous reference percentiles for 14 laboratory parameters in the CALIPER cohort of healthy children and adolescents. Clinical Chemistry and Laboratory Medicine. ISSN 1434-6621. 61(6). doi: 10.1515/cclm-2022-1077. Full text in Research Archive Show summary

  Objectives Marked physiological changes in growth and development present challenges in defining pediatric reference intervals for biomarkers of health and disease. Lambda, Mu, and Sigma (LMS)-based statistical modeling provides a continuous normal distribution by negating skewness and variation, and is commonly used to establish growth charts. Such LMS reference curves are suggested to enhance laboratory test result interpretation. The current study establishes LMS-based continuous reference percentiles for 14 biomarkers in the CALIPER cohort of healthy children and adolescents. Methods Data from healthy children and adolescents aged 1–<19 years were used to establish continuous reference percentiles using a novel LMS-based statistical method, including 2.5th, 25th, 50th, 75th, and 97.5th percentiles. The LMS approach applies a Box-Cox data transformation and summarizes continuous distributions by age via three curves: skewness (Lambda), median (Mu), and coefficient of variation (Sigma). Results LMS-based percentiles and z-scores were generated for 14 common pediatric biomarkers that demonstrate dynamic concentration patterns with age (e.g., alkaline phosphatase) and/or wherein the magnitude of difference from the population mean may be clinically relevant (e.g., triglycerides). The LMS model captured age- and sex-specific distributions accurately and was not substantially influenced by outlying points. Conclusions This is the first study to establish LMS-based continuous reference percentiles for biochemical markers in a healthy Canadian pediatric population. The current LMS-based approach builds upon previous continuous reference interval models by providing graded percentiles to improve test result interpretation, particularly with repeated measures over time. This method may assist in facilitating a patient-centered approach to laboratory medicine.

• Madsen, Andre; Almås, Bjørg; Bruserud, Ingvild Særvold; Oehme, Ninnie Helen Bakken; Nielsen, Christopher Sivert & Roelants, Mathieu [Show all 13 contributors for this article] (2022). Reference Curves for Pediatric Endocrinology: Leveraging Biomarker Z-Scores for Clinical Classifications. Journal of Clinical Endocrinology and Metabolism (JCEM). ISSN 0021-972X. 107(7), p. 2004–2015. doi: 10.1210/clinem/dgac155. Full text in Research Archive Show summary

  Context Hormone reference intervals in pediatric endocrinology are traditionally partitioned by age and lack the framework for benchmarking individual blood test results as normalized z-scores and plotting sequential measurements onto a chart. Reference curve modeling is applicable to endocrine variables and represents a standardized method to account for variation with gender and age. Objective We aimed to establish gender-specific biomarker reference curves for clinical use and benchmark associations between hormones, pubertal phenotype, and body mass index (BMI). Methods Using cross-sectional population sample data from 2139 healthy Norwegian children and adolescents, we analyzed the pubertal status, ultrasound measures of glandular breast tissue (girls) and testicular volume (boys), BMI, and laboratory measurements of 17 clinical biomarkers modeled using the established “LMS” growth chart algorithm in R. Results Reference curves for puberty hormones and pertinent biomarkers were modeled to adjust for age and gender. Z-score equivalents of biomarker levels and anthropometric measurements were compiled in a comprehensive beta coefficient matrix for each gender. Excerpted from this analysis and independently of age, BMI was positively associated with female glandular breast volume (β = 0.5, P < 0.001) and leptin (β = 0.6, P < 0.001), and inversely correlated with serum levels of sex hormone-binding globulin (SHBG) (β = −0.4, P < 0.001). Biomarker z-score profiles differed significantly between cohort subgroups stratified by puberty phenotype and BMI weight class. Conclusion Biomarker reference curves and corresponding z-scores provide an intuitive framework for clinical implementation in pediatric endocrinology and facilitate the application of machine learning classification and covariate precision medicine for pediatric patients.

• Hope, Sigrun; Nærland, Terje; Høyland, Anne Lise; Torske, Tonje; Malt, Eva & Abrahamsen, Tore G [Show all 16 contributors for this article] (2020). Higher vitamin B12 levels in neurodevelopmental disorders than in healthy controls and schizophrenia A comparison among participants between 2 and 53 years. The FASEB Journal. ISSN 0892-6638. 34(6), p. 8114–8124. doi: 10.1096/fj.201900855RRR. Full text in Research Archive Show summary

  Recent studies suggest that both high and low levels of vitamin B12 (vitB12) may have negative health impacts. We measured VitB12 in patients with the Neurodevelopmental disorders (ND) (n = 222), comprised of Autism Spectrum Disorders, specific Developmental disorders, and Intellectual Disability (aged 2‐53 years), schizophrenia (n = 401), and healthy controls (HC) (n = 483). Age‐and gender‐adjusted vitB12 z‐scores were calculated by comparisons with a reference population (n = 76 148). We found higher vitB12 in ND (median 420 pmol/L, mean z‐score: 0.30) than in HC (316 pmol/L, z‐score: 0.06, P < .01) and schizophrenia (306 pmol/L, z‐score: −0.02, P < .001), which was significant after adjusting for age, gender, vitB12 supplement, folate, hemoglobin, leukocytes, liver, and kidney function (P < .02). In ND, 20% (n = 44) had vitB12 above 650 pmol/L, and 1% (n = 3) had below 150 pmol/L (common reference limits). In 6.3% (n = 14) of ND, vitB12 was above 2SD of mean in the age‐and gender‐adjusted reference population, which was more frequent than in HC (n = 8, 1.6%), OR: 4.0, P = .001. Low vitB12 was equally frequent as in HC, and vitB12 z‐scores were equal across the age groups. To conclude, vitB12 was higher in ND than in HC and schizophrenia, suggesting a specific feature of ND, which warrants further studies to investigate the underlying mechanisms.

• Hundhausen, Thomas Eckhard; Lacsamana, Nancy; Tednes, Uraiwan & Slettan, Audun (2014). RHD-genotyping ved bruk av allel-spesifikk "Loop-mediated isothermal DNA Amplification". Bioingeniøren. ISSN 0801-6828. 49(3), p. 16–21. Full text in Research Archive

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• Hundhausen, Thomas Eckhard (2015). Vitamin B12 i Vest-Agder - Referanseintervaller. Full text in Research Archive
• Hundhausen, Thomas Eckhard & Milan, Elena Margarita (2015). Hæmatologi for 8. trinn-elever, ungdomsskole. Full text in Research Archive
• Hundhausen, Thomas Eckhard (2013). Protrahert væskedeficit hos trombocytt-aferese-givere. Full text in Research Archive
• Hundhausen, Thomas Eckhard; Mathiassen, M.; Børresen, H.U.; Nedal, K.A. & Olsen, Odd Harald (2013). PROLONGED INTRAVASAL FLUID DEFICITS IN PLATELETPHERESIS DONORS. Vox Sanguinis. ISSN 0042-9007. 105, p. 49–49. Full text in Research Archive
• Hundhausen, Thomas Eckhard & Milan, Elena Margarita (2012). Hæmatologi for 8. trinn-elever, ungdomsskole. Full text in Research Archive
• Hundhausen, Thomas Eckhard (2012). Infeksjoner som kan overføres ved transfusjon. Full text in Research Archive
• Hundhausen, Thomas Eckhard (2011). Hæmatologi for 8. trinn-elever, ungdomsskole. Full text in Research Archive

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