Pediatric reference value distributions and covariate-stratified reference intervals for 29 endocrine and special chemistry biomarkers on the Beckman Coulter Immunoassay Systems: a CALIPER study of healthy community children

Author(s):  
Kimiya Karbasy ◽  
Danny C.C. Lin ◽  
Alexandra Stoianov ◽  
Man Khun Chan ◽  
Victoria Bevilacqua ◽  
...  

AbstractThe CALIPER program is a national research initiative aimed at closing the gaps in pediatric reference intervals. CALIPER previously reported reference intervals for endocrine and special chemistry markers on Abbott immunoassays. We now report new pediatric reference intervals for immunoassays on the Beckman Coulter Immunoassay Systems and assess platform-specific differences in reference values.A total of 711 healthy children and adolescents from birth to <19 years of age were recruited from the community. Serum samples were collected for measurement of 29 biomarkers on the Beckman Coulter Immunoassay Systems. Statistically relevant age and/or gender-based partitions were determined, outliers removed, and reference intervals calculated in accordance with Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines.Complex profiles were observed for all 29 analytes, necessitating unique age and/or sex-specific partitions. Overall, changes in analyte concentrations observed over the course of development were similar to trends previously reported, and are consistent with biochemical and physiological changes that occur during childhood. Marked differences were observed for some assays including progesterone, luteinizing hormone and follicle-stimulating hormone where reference intervals were higher than those reported on Abbott immunoassays and parathyroid hormone where intervals were lower.This study highlights the importance of determining reference intervals specific for each analytical platform. The CALIPER Pediatric Reference Interval database will enable accurate diagnosis and laboratory assessment of children monitored by Beckman Coulter Immunoassay Systems in health care institutions worldwide. These reference intervals must however be validated by individual labs for the local pediatric population as recommended by CLSI.

2012 ◽  
Vol 58 (5) ◽  
pp. 854-868 ◽  
Author(s):  
David A Colantonio ◽  
Lianna Kyriakopoulou ◽  
Man Khun Chan ◽  
Caitlin H Daly ◽  
Davor Brinc ◽  
...  

Abstract BACKGROUND Pediatric healthcare is critically dependent on the availability of accurate and precise laboratory biomarkers of pediatric disease, and on the availability of reference intervals to allow appropriate clinical interpretation. The development and growth of children profoundly influence normal circulating concentrations of biochemical markers and thus the respective reference intervals. There are currently substantial gaps in our knowledge of the influences of age, sex, and ethnicity on reference intervals. We report a comprehensive covariate-stratified reference interval database established from a healthy, nonhospitalized, and multiethnic pediatric population. METHODS Healthy children and adolescents (n = 2188, newborn to 18 years of age) were recruited from a multiethnic population with informed parental consent and were assessed from completed questionnaires and according to defined exclusion criteria. Whole-blood samples were collected for establishing age- and sex-stratified reference intervals for 40 serum biochemical markers (serum chemistry, enzymes, lipids, proteins) on the Abbott ARCHITECT c8000 analyzer. RESULTS Reference intervals were generated according to CLSI C28-A3 statistical guidelines. Caucasians, East Asians, and South Asian participants were evaluated with respect to the influence of ethnicity, and statistically significant differences were observed for 7 specific biomarkers. CONCLUSIONS The establishment of a new comprehensive database of pediatric reference intervals is part of the Canadian Laboratory Initiative in Pediatric Reference Intervals (CALIPER). It should assist laboratorians and pediatricians in interpreting test results more accurately and thereby lead to improved diagnosis of childhood diseases and reduced patient risk. The database will also be of global benefit once reference intervals are validated in transference studies with other analytical platforms and local populations, as recommended by the CLSI.


Author(s):  
Mary Kathryn Bohn ◽  
Siobhan Wilson ◽  
Alexandra Hall ◽  
Khosrow Adeli

Abstract Objectives The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) has developed an extensive database of reference intervals (RIs) for several biomarkers on various analytical systems. In this study, pediatric RIs were verified for key immunoassays on the Abbott Alinity system based on the analysis of healthy children samples and comparison to comprehensive RIs previously established for Abbott ARCHITECT assays. Methods Analytical performance of Alinity immunoassays was first assessed. Subsequently, 100 serum samples from healthy children recruited with informed consent were analyzed for 16 Alinity immunoassays. The percentage of test results falling within published CALIPER ARCHITECT reference and confidence limits was determined. If ≥ 90% of test results fell within the confidence limits, they were considered verified based on CLSI guidelines. If <90% of test results fell within the confidence limits, additional samples were analyzed and new Alinity RIs were established. Results Of the 16 immunoassays assessed, 13 met the criteria for verification with test results from ≥ 90% of healthy serum samples falling within the published ARCHITECT confidence limits. New CALIPER RIs were established for free thyroxine and prolactin on the Alinity system. Estradiol required special considerations in early life. Conclusions Our data demonstrate excellent concordance between ARCHITECT and Alinity immunoassays, as well as the robustness of previously established CALIPER RIs for most immunoassays, eliminating the need for de novo RI studies for most parameters. Availability of pediatric RIs for immunoassays on the Alinity system will assist clinical laboratories using this new platform and contribute to improved clinical decision-making.


2018 ◽  
Vol 56 (6) ◽  
pp. 964-972 ◽  
Author(s):  
Victoria Higgins ◽  
Dorothy Truong ◽  
Nicole M.A. White-Al Habeeb ◽  
Angela W.S. Fung ◽  
Barry Hoffman ◽  
...  

Abstract Background: 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active vitamin D metabolite, plays a critical role in calcium and phosphate homeostasis. 1,25(OH)2D is measured to assess calcium and phosphate metabolism, particularly during periods of profound growth and development. Despite its importance, no reliable pediatric reference interval exists, with those available developed using adult populations or out-dated methodologies. Using the fully automated chemiluminescence immunoassay by DiaSorin, we established 1,25(OH)2D pediatric reference intervals using healthy children and adolescents from the CALIPER cohort. Methods: Serum samples from healthy subjects (0 to <19 years) were analyzed for 1,25(OH)2D using the DiaSorin LIAISON XL assay and age-specific reference intervals were established. The Mann-Whitney U-test was used to determine seasonal differences. Pooled neonatal and infantile samples were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine if elevated concentrations during the first year of life may be attributed to cross-reacting moieties. Results: Three reference interval age partitions were required with highest levels in subjects 0 to <1 year (77–471 pmol/L), which declined and narrowed after 1 year (113–363 pmol/L) and plateaued at 3 years (108–246 pmol/L). 1,25(OH)2D concentration was not significantly affected by seasonal variation or sex. Elevated 1,25(OH)2D concentrations in neonatal and infantile samples may be the result of an interfering substance. The absence of 3-epi-1,25-dihydroxyvitamin D in the pooled samples makes it unlikely to be the interfering moiety. Conclusions: Pediatric reference intervals for 1,25(OH)2D were established to improve test result interpretation in children and adolescents. 1,25(OH)2D is elevated in a proportion of neonates and infants, which may be the result of a cross-reacting moiety.


2019 ◽  
Vol 47 (7) ◽  
pp. 3151-3159 ◽  
Author(s):  
Changjin Liu ◽  
Jing Wen ◽  
Jialin Xiang ◽  
Xuhong Ouyang ◽  
Yan Yang ◽  
...  

Objective This study aimed to investigate serum levels of the cystatin C (CysC)/creatinine (Cr) ratio and renal serum markers (CysC, Cr, urea, and uric acid [UA]) for different ages and by sex. We also aimed to establish pediatric reference intervals for the serum CysC/Cr ratio. Methods Serum samples were collected from 4765 healthy children (0–18 years old). Serum markers of renal function were measured, and the CysC/Cr ratio of each participant was calculated and statistically analyzed. Results The renal marker CysC did not substantially change after 1 year old. Cr, urea, and UA levels generally increased with age. However, the serum CysC/Cr ratio steadily decreased with age. The CysC/Cr ratio showed significant differences in age among all age groups and varied with sex, except for in the 1 to 6-year-old groups. The overall serum CysC/Cr ratio in girls was higher than that in boys. Conclusion Reference intervals of the serum CysC/Cr ratio in the pediatric population were established. These intervals need to be partitioned by age and sex.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A730-A731
Author(s):  
Ruhan Wei ◽  
Kathleen Bowers ◽  
Grace M Kroner ◽  
Drew Payto ◽  
Jessica Colon Franco

Abstract Introduction: Androstenedione is a common precursor of male and female sex hormones produced by the adrenal glands and gonads. Serum androstenedione is a helpful biomarker in the diagnostic workup of a subset of patients with polycystic ovary syndrome (PCOS), the investigation of virilizing endocrinopathies, and for monitoring pediatric patients with congenital adrenal hyperplasia. The gold standard for the measurement of androstenedione is LC-MS/MS. A newly developed androstenedione competitive immunoassay is now available in the US, the Roche Elecsys Androstenedione (ASD) immunoassay. Until recently, the Siemens Immulite assay was the only non-radioimmunologic immunoassay available. We characterized the analytical and clinical performance of the ASD across different patient populations and in comparison to the Immulite and an LC-MS/MS assay. Methods and materials: The experiments performed were: linearity and analytical measuring range (AMR), precision (intra- and inter-assay), and accuracy. Androstenedione was measured on de-identified residual serum samples (n=40) using the ASD and Immulite immunoassays and an LC-MS/MS assay. The reference intervals (RIs) provided by Roche for healthy male (0.280-1.52 ng/mL), healthy female (0.490-1.31 ng/mL), postmenopausal women (0.187-1.07 ng/mL), healthy children (&lt;0.519 ng/mL), and patients with PCOS (0.645-3.47 ng/mL) were verified with at least 20 specimens, according to CLSI C28A3. Statistical analysis was performed using EP Evaluator and R program. Results: The ASD had a linear response across the AMR of 0.3 to 10.0 ng/mL. The inter- and intra-assay coefficients of variation were 4.5% and 2.0% or lower, at concentrations 0.5-6.7 ng/mL, respectively. The ASD and LC-MS/MS assays had a mean bias of -0.0542 ng/mL (-2%), Deming regression of y = 1.000 [0.961; 1.039] x - 0.0548 [-0.1806; 0.0709], and r = 0.9930. The Immulite assay had a mean bias of 1.15 ng/mL (44%) and 1.22 ng/mL (32%) compared to the LC-MS/MS and ASD assays, respectively. The recommended RIs from Roche for healthy male, female, and postmenopausal female groups were successfully verified in our patient population. However, the androstenedione concentrations for the healthy children and PCOS groups were outside of the suggested RIs, with concentrations up to 1.41 ng/mL and 0.527-2.24 ng/mL, respectively. Unlike published elsewhere, hormone therapies such as contraceptive pills and steroid treatments did not significantly affect serum androstenedione concentrations in healthy females and patients with PCOS. Conclusion: The ASD is superior to the Immulite immunoassay, and it has excellent comparability with the LC-MS/MS for serum androstenedione measurement. The RIs published by Roche may not be universally transferable; verification is recommended, and establishing RIs for the pediatric population may be necessary.


2014 ◽  
Vol 60 (12) ◽  
pp. 1532-1542 ◽  
Author(s):  
Victoria Bevilacqua ◽  
Man Khun Chan ◽  
Yunqi Chen ◽  
David Armbruster ◽  
Beth Schodin ◽  
...  

Abstract BACKGROUND Cancer biomarkers are commonly used in pediatrics to monitor cancer progression, recurrence, and prognosis, but pediatric reference value distributions have not been well established for these markers. The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) sought to develop a pediatric database of covariate-stratified reference value distributions for 11 key circulating tumor markers, including those used in assessment of patients with childhood or adult cancers. METHODS Healthy community children from birth to 18 years of age were recruited to participate in the CALIPER project with informed parental consent. We analyzed serum samples from 400–700 children (depending on the analyte in question) on the Abbott Architect ci4100 and established reference intervals for α-fetoprotein (AFP), antithyroglobulin (anti-Tg), human epididymis protein 4 (HE4), cancer antigen 125 (CA125), CA15-3, CA19-9, progastrin-releasing peptide (proGRP), carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), and total and free prostate specific antigen (PSA) according to CLSI C28-A3 statistical guidelines. RESULTS We observed significant fluctuations in biomarker concentrations by age and/or sex in 10 of 11 biomarkers investigated. Age partitioning was required for CA153, CA125, CA19-9, CEA, SCC, proGRP, total and free PSA, HE4, and AFP, whereas sex partitioning was also required for CA125, CA19-9, and total and free PSA. CONCLUSIONS This CALIPER study established a database of childhood reference intervals for 11 tumor biomarkers and revealed dramatic fluctuations in tumor marker concentrations between boys and girls and throughout childhood. In addition, important differences between the adult and pediatric population were observed, further highlighting the need for pediatric-specific reference intervals.


Author(s):  
Emily Lam ◽  
Victoria Higgins ◽  
Liyong Zhang ◽  
Man Khun Chan ◽  
Mary Kathryn Bohn ◽  
...  

Abstract Background Cardiac troponin (cTn) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are increasingly used clinically to evaluate and prognosticate acute myocardial infarction and heart failure, respectively. Pediatric reference intervals and cut-offs have not been established for Roche’s Elecsys Troponin T hs (high sensitive) assay. Although pediatric reference intervals exist for NT-proBNP, cut-off values do not exist. In this study, we report reference intervals and 99th percentile cut-offs in a large, healthy Canadian pediatric population using the CALIPER cohort. Methods Blood samples from 484 healthy children and adolescents between 0 and &lt;19 years old were recruited from hospital outpatient clinics and community settings. Serum samples were analyzed using Roche’s Cobas e411 and evaluated for high-sensitivity cTnT (hs-cTnT) and NT-proBNP concentrations. 95% reference intervals and 99th percentile cut-off values were established. Results Three hs-cTnT age partitions were established (0 to &lt;6 months, 6 months to &lt;1 year, and 1 to &lt;19 years) with highest concentrations observed in children under 1 year. Two NT-proBNP age partitions were established (0 to &lt;1 year, and 1 to &lt;19 years), also with higher concentrations in infants under 1 year of age. For each of these age partitions, the 99th percentile cut-off, 95% reference interval, and proportion of detectable concentrations were determined. Conclusions This is the first study to examine hs-cTnT and NT-proBNP reference values together in a healthy pediatric cohort without other clinical indications. We present 99th percentile cut-offs, which will allow clinicians to appropriately evaluate cardiovascular disease in children and adolescents.


Author(s):  
Jisook Yim ◽  
Soo Beom Kwon ◽  
Jung Sun Han ◽  
Jeong-Ho Kim ◽  
Eun Hee Lee ◽  
...  

Context.— Recently, an exchangeable copper (CuEXC) assay has been suggested as a robust and feasible diagnostic tool for Wilson disease (WD). Although WD is a disorder that requires lifelong treatment and monitoring, few data are currently available regarding the status of copper levels in children. Objective.— To evaluate the performance of copper assays and establish a reference interval for total copper and CuEXC in the pediatric population. Design.— Serum samples from children aged 1–5 (n = 122), 6–12 (n = 125), and 13–18 years (n = 120) were analyzed. Total copper and CuEXC concentrations were directly measured using inductively coupled plasma mass spectrometry, and relative CuEXC levels were calculated. Total copper reference intervals, CuEXC levels, and relative CuEXC levels were determined based on the 2.5th and 97.5th percentiles of the data with 90% confidence intervals. Results.— There were significant differences in the median concentrations of total copper and relative CuEXC among the age groups. Reference intervals determined for total copper were 82 to 167, 75 to 139, and 64 to 133 μg/dL for children aged 1 to 5, 6 to 12, and 13 to 18 years, respectively. The reference intervals for CuEXC were 4.29 to 9.79, 4.02 to 9.09, and 3.55 to 8.25 μg/dL for children aged 1 to 5, 6 to 12, and 13 to 18 years, respectively. Among 11 patients with suspected WD, relative CuEXC values were elevated in all 3 diagnosed with WD. Conclusions.— The pediatric reference intervals derived in this study are expected to be useful for the diagnosis, differential diagnosis, treatment, and monitoring of pediatric patients with WD.


Author(s):  
Eduardo Martínez-Morillo ◽  
Anastasia Diamandis ◽  
Eleftherios P. Diamandis

AbstractKallikrein 6 (KLK6) is a serine protease involved in numerous cellular processes, up-regulated in many cancers and associated with some neurodegenerative disorders. The aim of this study was to establish a reference interval and estimate the biological variation of KLK6 in serum samples of adults. Furthermore, levels of this protein in patients with renal failure were also studied.Serum samples from healthy volunteers (n=136) were collected. Between 15 and 18 additional samples from four of these subjects were obtained over a period of 2 months. Samples from individuals (n=1043) who visited the University Health Network for a routine check-up were collected to study the association between KLK6 with age and gender. Samples from patients with renal failure (n=106) were also obtained and KLK6 and creatinine concentrations were analyzed by ELISA and an automated enzymatic method, respectively.The reference interval was established to be 1.04–3.93 ng/mL. The index of individuality was 0.43 and the reference change value was 35%. Only two serum samples would be required to estimate the homeostatic setting point of an individual. There is a weak but highly significant positive correlation between KLK6 and age (p<0.0001). Furthermore, there is a significant positive correlation between serum concentrations of KLK6 and creatinine (p<0.0001), in patients with renal failure.The established reference interval for KLK6 and the estimation of its biological variation will further aid in the clinical use of this protein as a serum marker of malignancy and other diseases.


2020 ◽  
Vol 58 (4) ◽  
pp. 605-617 ◽  
Author(s):  
Houman Tahmasebi ◽  
Shervin Asgari ◽  
Alexandra Hall ◽  
Victoria Higgins ◽  
Ashfia Chowdhury ◽  
...  

AbstractBackgroundAccurate pediatric reference intervals (RIs) for laboratory tests determined in a healthy pediatric population are essential for correct laboratory test interpretation and clinical decision-making. In pediatrics, RIs require partitioning by age and/or sex; however, the need for partitioning based on ethnicity is unclear. Here, we assessed the influence of ethnicity on biomarker concentrations in the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) cohort of healthy children and adolescents and compared the results with the National Health and Nutrition Examination Survey (NHANES).MethodsA total of 52 biomarkers were measured in a multiethnic population of 846–1179 healthy children (aged 5 to <19 years) upon informed consent. Biomarker concentrations were retrospectively compared between four major ethnic groups (i.e. Black, Caucasian, East Asian, and South Asian, determined by parental ethnicity). Retrospective results were verified prospectively using an additional 500 healthy pediatric samples with equal sample size across ethnicities. Ethnic-specific differences were assessed based on statistical significance and biological and analytical variations. Appropriate age-, sex-, and ethnic-specific RIs were calculated.ResultsEthnic-specific differences were not observed for 34 biomarkers examined in the retrospective analysis, while 18 demonstrated statistically significant ethnic differences. Among these, seven analytes demonstrated ethnic-specific differences in the prospective analysis: vitamin D, amylase, ferritin, follicle-stimulating hormone (FSH), immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM). Analysis of select NHANES data confirmed CALIPER findings.ConclusionsThis is the first comprehensive Canadian pediatric study examining ethnic-specific differences in common biomarkers. While the majority of biomarkers did not require ethnic partitioning, ethnic-specific RIs were established for seven biomarkers showing marked differences. Further studies in other populations are needed to confirm our findings.


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