scholarly journals Age- and sex-specific reference intervals for the serum cystatin C/creatinine ratio in healthy children (0–18 years old)

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.

1988 ◽  
Vol 34 (8) ◽  
pp. 1625-1628 ◽  
Author(s):  
G Lockitch ◽  
A C Halstead ◽  
L Wadsworth ◽  
G Quigley ◽  
L Reston ◽  
...  

Abstract Age- and sex-specific reference intervals based on the 0.025 and 0.975 fractiles of data derived from a healthy pediatric population are presented for zinc, copper, selenium, iron, ferritin, retinol, alpha-tocopherol, and related analytes in serum. Age was an important covariate for copper, selenium, retinol, and tocopherol, and ferritin in boys. Strong correlations were found between retinol and retinol-binding protein, prealbumin (transthyretin), alpha-tocopherol, and selenium. Tocopherol was highly correlated with both cholesterol and triglycerides. We found no relationship between serum zinc and either retinol or retinol-binding protein. Despite exclusion of children in whom anemia, microcytosis, or variant hemoglobins were found, the 0.025 fractile for iron in several age groups was even less than the concentration considered to indicate poor iron nutritional status.


Author(s):  
Mary Kathryn Bohn ◽  
Paul Horn ◽  
Donna League ◽  
Paul Steele ◽  
Alexandra Hall ◽  
...  

Abstract Objectives Rapid development in childhood and adolescence combined with lack of immunoassay standardization necessitates the establishment of age-, sex-, and assay-specific reference intervals for immunochemical markers. This study established reference intervals for 11 immunoassays on the new Siemens Healthineers Atellica® IM Analyzer in the healthy CALIPER cohort. Methods A total of 600 healthy participants (birth to 18 years) were recruited from the community, and serum samples were collected with informed consent. After sample analysis, age- and sex-specific differences were assessed, and outliers were removed. Reference intervals were established using the robust method (40–<120 participants) or nonparametric method (≥120 participants). Results Of the 11 immunoassays studied, nine required age partitioning (i.e., dehydroepiandrosterone-sulfate, estradiol, ferritin, folate, follicle-stimulating hormone, luteinizing hormone, progesterone, testosterone, vitamin B12), and seven required sex partitioning. Free thyroxine and thyroid-stimulating hormone demonstrated no significant age- and/or sex-specific differences. Conclusions Overall, the age- and sex-specific trends observed closely mirrored those previously reported by CALIPER on other platforms as well as other internationally recognized studies. However, established lower and upper limits demonstrated some discrepancies between published values from healthy cohorts on alternate analytical systems, highlighting differences between manufacturers and the need for platform-specific reference intervals for informed pediatric 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.


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.


2018 ◽  
Vol 56 (8) ◽  
pp. 1319-1327 ◽  
Author(s):  
Olivier Grunewald ◽  
Benjamin Lopez ◽  
Séverine Brabant ◽  
Stéphanie Rogeau ◽  
Antoine Deschildre ◽  
...  

Abstract Background: Immunoglobulin G (IgG) and IgG subclass assays are indicated in patients with suspected primary immunodeficiency (PID). Commercially available assays for IgG subclass determination are calibrated against various preparations, and so specific reference values are required for each of them. Using Optilite® reagents from The Binding Site Group Ltd., we sought to determine the pediatric IgG and IgG subclass reference intervals with respect to the ERM-DA470k certified reference material. Methods: Levels of IgG and IgG subclasses were analyzed in serum samples collected from a large cohort of PID-free children and adolescents. Reference intervals were calculated for previously published age groups (6–12 months, 12–18 months, 18 months–2 years, 2–3 years, 3–4 years, 4–6 years, 6–9 years, 9–12 years and 12–18 years), according to the Clinical and Laboratory Standards Institute’s C28-A3c protocol. Results: A total of 456 serum samples were analyzed. The correlation between the total IgG and the sum of the IgG subclasses was good (r2=0.96). No statistically significant gender-specific differences were observed. Our results for the changes over time in IgG and IgG subclass levels are consistent with previous reports. The differences between our lower/upper reference limits and those in the literature are probably due to variations in calibration. Conclusions: Our present results provide a reliable basis for the diagnosis of PIDs in childhood and for the accreditation of laboratories using Optilite® immunoturbidimetric reagents for IgG subclass measurement. Laboratory scientists and clinicians should be aware of the need for manufacturer-specific IgG subclass reference intervals.


2013 ◽  
Vol 59 (8) ◽  
pp. 1215-1227 ◽  
Author(s):  
Danijela Konforte ◽  
Jennifer L Shea ◽  
Lianna Kyriakopoulou ◽  
David Colantonio ◽  
Ashley H Cohen ◽  
...  

BACKGROUND Pediatric endocrinopathies are commonly diagnosed and monitored by measuring hormones of the hypothalamic-pituitary-gonadal axis. Because growth and development can markedly influence normal circulating concentrations of fertility hormones, accurate reference intervals established on the basis of a healthy, nonhospitalized pediatric population and that reflect age-, gender-, and pubertal stage–specific changes are essential for test result interpretation. METHODS Healthy children and adolescents (n = 1234) were recruited from a multiethnic population as part of the CALIPER study. After written informed parental consent was obtained, participants filled out a questionnaire including demographic and pubertal development information (assessed by self-reported Tanner stage) and provided a blood sample. We measured 7 fertility hormones including estradiol, testosterone (second generation), progesterone, sex hormone–binding globulin, prolactin, follicle-stimulating hormone, and luteinizing hormone by use of the Abbott Architect i2000 analyzer. We then used these data to calculate age-, gender-, and Tanner stage–specific reference intervals according to Clinical Laboratory Standards Institute C28-A3 guidelines. RESULTS We observed a complex pattern of change in each analyte concentration from the neonatal period to adolescence. Consequently, many age and sex partitions were required to cover the changes in most fertility hormones over this period. An exception to this was prolactin, for which no sex partition and only 3 age partitions were necessary. CONCLUSIONS This comprehensive database of pediatric reference intervals for fertility hormones will be of global benefit and should lead to improved diagnosis of pediatric endocrinopathies. The new database will need to be validated in local populations and for other immunoassay platforms as recommended by the Clinical Laboratory Standards Institute.


2019 ◽  
Vol 57 (12) ◽  
pp. 1968-1979 ◽  
Author(s):  
Mary Kathryn Bohn ◽  
Victoria Higgins ◽  
Shervin Asgari ◽  
Felix Leung ◽  
Barry Hoffman ◽  
...  

Abstract Background The diagnostic utility of laboratory tests in paediatric medicine relies heavily on the availability of appropriate reference intervals (RIs). The Canadian Laboratory Initiative on Paediatric Reference Intervals (CALIPER) has established a comprehensive database of covariate-stratified RIs for many paediatric laboratory tests using a large, healthy reference population. Several automated analysers in widespread use in clinical laboratories have already been studied. Here, we extend the testing to Roche immunoassays and report, for the first time, comprehensive paediatric RIs for 17 endocrine and special chemistry markers. Methods A total of 741 healthy children and adolescents (1 day to <19 years) were recruited and serum samples were analysed for 17 immunoassays on the Roche cobas 8000 e602 Immunoassay Analyzer. Age and sex-specific RIs were established and corresponding 90% confidence intervals (CIs) were calculated in accordance with Clinical and Laboratory Standards Institute guidelines. Results Reference values for all analytes measured required age partitioning, particularly during early life and throughout adolescence. Of the 17 analytes measured, eight required sex partitioning, including ferritin, thyroid stimulating hormone (TSH), total triiodothyronine (TT3) and all fertility/sex hormones, except prolactin. Conclusions This is the first study to determine accurate paediatric RIs for Roche immunoassays. RIs were generally similar to those previously published by CALIPER on other analytical platforms, highlighting the reproducibility of age- and sex-specific trends in reference values observed across the paediatric age range. The RIs established in this study will improve the accuracy of test result interpretation and clinical decision-making in clinical laboratories utilising Roche immunoassays.


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.


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