Determination of a Beckman Coulter AU turbidometric method-specific caeruloplasmin reference interval

2021 ◽  
pp. 000456322198936
Author(s):  
Olivia E Kaye ◽  
Paul Cook
Keyword(s):  
Renal Stones ◽  
Reference Interval ◽  
Reference Intervals ◽  
University Hospital ◽  
Specific Reference ◽  
Serum Samples ◽  
Rank Analysis ◽  
Local Reference ◽  
Local Determination

Background Method-dependent variation of caeruloplasmin measurement is significant and necessitates the requirement for assay-specific reference intervals. Local determination becomes necessary in the absence of suitable published or manufacturer-quoted reference intervals. Methods Applicability of the Beckman Coulter AU-quoted reference interval was determined by assay of 20 surplus serum samples from patients attending the medical renal stones clinic at University Hospital Southampton. Subsequently, 60 additional samples were collected for local reference interval determination. Samples were analysed for caeruloplasmin using the Beckman Coulter AU turbidometric kit on an AU680 analyser. Outliers were removed, and non-parametric rank analysis of the results was performed. Results The Beckman Coulter-quoted reference interval of 200–600 mg/L was unsuitable with 40% of the verification samples falling below 200 mg/L. A caeruloplasmin reference interval of 150–320 mg/L was established. Conclusion Users should be aware the quoted Beckman Coulter AU turbidometric reference interval may not be appropriate. We have established a method-specific adult reference interval for routine use.

Pediatric reference intervals for 1,25-dihydroxyvitamin D using the DiaSorin LIAISON XL assay in the healthy CALIPER cohort

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 ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Critical Role ◽  
Reference Interval ◽  
Reference Intervals ◽  
Biologically Active ◽  
Specific Reference ◽  
Healthy Children ◽  
Serum Samples ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D

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.

scholarly journals Nomogram of age-specific anti-Müllerian hormone levels in healthy Egyptian females

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254858
Author(s):  
Eman Ahmed El-Attar ◽  
Tamer A. Hosny ◽  
Kiyoshi Ichihara ◽  
Rania N. Bedair ◽  
Ahmed Salah El-Din Tork
Keyword(s):  
Reference Interval ◽  
Reference Intervals ◽  
Specific Reference ◽  
Clinical Settings ◽  
Power Transformation ◽  
Serum Samples ◽  
Female Age ◽  
Age Related ◽  
Age Dependent ◽  
Age Range

Background Anti-Müllerian hormone (AMH) is an important determinant of ovarian reserve in fertility workups in many clinical settings. Thus, we investigated the age dependent decline in AMH specific to the Egyptian population and sought to establish an age dependent reference interval parametrically. Methods Serum samples were collected from 841 apparently healthy women. AMH was measured using an electro-chemiluminescent technique. Box-Cox power transformation was used to make the AMH distribution Gaussian for parametric derivation of reference intervals. Results Power of 0.4 was found optimal for Gaussian transformation of AMH reference values. We demonstrate the strong negative relation between circulating AMH and female age with Spearman’s correlation coefficient of rS = −0.528. Age-specific reference interval was determined for every 5 years of age from 16 to 49, and nomogram was constructed by smoothing the lines connecting adjacent lower and upper reference limits. Conclusion The age-specific reference intervals and the age-AMH nomogram could be valuable in the clinical practice of in reproductive medicine. To our knowledge, this is the first study to confirm AMH levels in Egyptian females. We were able to explore age-related AMH levels specific to Egyptian females in the fertile age group and to treat skewed AMH data in a multi-step scheme using power transformation. Thus, a more accurate nomogram was constructed accommodating a profile delineated for a wide age range and a rescaled AMH axis improving its usability.

EXPRESS: Method dependent variation in TSH and FT4 reference intervals in pregnancy: a systematic review

2021 ◽  
pp. 000456322110269
Author(s):  
O E Okosieme ◽  
Medha Agrawal ◽  
Danyal Usman ◽  
Carol Evans
Keyword(s):  
Systematic Review ◽  
Reference Interval ◽  
First Trimester ◽  
Reference Intervals ◽  
Assay Method ◽  
Specific Reference ◽  
Upper Limits ◽  
Wide Range ◽  
Assay Methods ◽  
In Pregnancy

Background: Gestational TSH and FT4 reference intervals may differ according to assay method but the extent of variation is unclear and has not been systematically evaluated. We conducted a systematic review of published studies on TSH and FT4 reference intervals in pregnancy. Our aim was to quantify method-related differences in gestation reference intervals, across four commonly used assay methods, Abbott, Beckman, Roche, and Siemens. Methods: We searched the literature for relevant studies, published between January 2000 and December 2020, in healthy pregnant women without thyroid antibodies or disease. For each study, we extracted trimester-specific reference intervals (2.5–97.5 percentiles) for TSH and FT4 as well as the manufacturer provided reference interval for the corresponding non-pregnant population. Results: TSH reference intervals showed a wide range of study-to-study differences with upper limits ranging from 2.33 to 8.30 mU/L. FT4 lower limits ranged from 4.40–13.93 pmol/L, with consistently lower reference intervals observed with the Beckman method. Differences between non-pregnant and first trimester reference intervals were highly variable, and for most studies the TSH upper limit in the first trimester could not be predicted or extrapolated from non-pregnant values. Conclusions: Our study confirms significant intra and inter-method disparities in gestational thyroid hormone reference intervals. The relationship between pregnant and non-pregnant values is inconsistent and does not support the existing practice in some laboratories of extrapolating gestation references from non-pregnant values. Laboratories should invest in deriving method-specific gestation reference intervals for their population.

Evaluation of Thyroid Function in Pregnant Women Using Automated Immunoassays

2021 ◽  
Author(s):  
K Aaron Geno ◽  
Matthew S Reed ◽  
Mark A Cervinski ◽  
Robert D Nerenz
Keyword(s):  
Pregnant Women ◽  
Equilibrium Dialysis ◽  
Reference Interval ◽  
First Trimester ◽  
Reference Intervals ◽  
Free Thyroxine ◽  
Specific Reference ◽  
Childbearing Age ◽  
Thyroid Autoantibody ◽  
The Impact

Abstract Introduction Automated free thyroxine (FT4) immunoassays are widely available, but professional guidelines discourage their use in pregnant women due to theoretical under-recoveries attributed to increased thyroid hormone binding capacity and instead advocate the use of total T4 (TT4) or free thyroxine index (FTI). The impact of this recommendation on the classification of thyroid status in apparently euthyroid pregnant patients was evaluated. Methods After excluding specimens with thyroid autoantibody concentrations above reference limits, thyroid-stimulating hormone (TSH), FT4, TT4, and T-uptake were measured on the Roche Cobas® platform in remnant clinical specimens from at least 147 nonpregnant women of childbearing age and pregnant women at each trimester. Split-sample comparisons of FT4 as measured by the Cobas and equilibrium dialysis were performed. Results FT4 decreased with advancing gestational age by both immunoassay and equilibrium dialysis. TSH declined during the first trimester, remained constant in the second, and increased throughout the third, peaking just before delivery. Interpretation of TT4 concentrations using 1.5-times the nonpregnant reference interval classified 13.6% of first trimester specimens below the lower reference limit despite TSH concentrations within trimester-specific reference intervals. Five FTI results from 480 pregnant individuals (about 1.0%) fell outside the manufacturer’s reference interval. Conclusions Indirect FT4 immunoassay results interpreted in the context of trimester-specific reference intervals provide a practical and viable alternative to TT4 or FTI. Declining FT4 and increasing TSH concentrations near term suggest that declining FT4 is not an analytical artifact but represents a true physiological change in preparation for labor and delivery.

Pediatric reference interval verification for endocrine and fertility hormone assays on the Abbott Alinity system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mary Kathryn Bohn ◽  
Siobhan Wilson ◽  
Alexandra Hall ◽  
Khosrow Adeli
Keyword(s):  
Clinical Decision Making ◽  
De Novo ◽  
Reference Interval ◽  
Clinical Decision ◽  
Reference Intervals ◽  
Healthy Children ◽  
Confidence Limits ◽  
Test Results ◽  
Serum Samples ◽  
Abbott Architect

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.

Distribution of HOMA-IR in a population-based cohort and proposal for reference intervals

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bassel Matli ◽  
Andreas Schulz ◽  
Thomas Koeck ◽  
Tanja Falter ◽  
Johannes Lotz ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fasting Glucose ◽  
Reference Group ◽  
Reference Interval ◽  
Population Based ◽  
Reference Intervals ◽  
Health Study ◽  
Specific Reference ◽  
Model Assessment ◽  
Significant Difference

Abstract Objectives Insulin resistance (IR) is a hallmark of type 2 diabetes mellitus (DM). The homeostatic model assessment of insulin resistance (HOMA-IR) provides an estimate for IR from fasting glucose and insulin serum concentrations. The aim of this study was to obtain a reference interval for HOMA-IR for a specific insulin immunoassay. Methods The Gutenberg Health Study (GHS) is a population-based, prospective, single-center cohort study in Germany with 15,030 participants aged 35–74 years. Fasting glucose, insulin, and C-peptide were available in 10,340 participants. HOMA-IR was calculated in this group and three reference subgroups with increasingly more stringent inclusion criteria. Age- and sex-dependent distributions of HOMA-IR and reference intervals were obtained. In a substudy three insulin assays were compared and HOMA-IR estimated for each assay. Results Among the 10,340 participants analyzed there were 6,590 non-diabetic, 2,901 prediabetic, and 849 diabetic individuals. Median (interquartile range [IQR]) HOMA-IR was 1.54 (1.13/2.19), 2.00 (1.39/2.99), and 4.00 (2.52/6.51), respectively. The most stringently selected reference group consisted of 1,065 persons. Median (IQR) HOMA-IR was 1.09 (0.85/1.42) with no significant difference between men and women. The 97.5th percentile was 2.35. There was a non-significant trend towards higher values with older age. Comparison of three immunoassays for insulin showed an unsatisfactory correlation among the assays and systematic differences in calculated HOMA-IR. Conclusions We present HOMA-IR reference intervals for adults derived by more or less stringent selection criteria for the reference cohort. In addition we show that assay specific reference intervals for HOMA-IR are required.

scholarly journals Early pregnancy reference intervals; 29 serum analytes from 4 to 12 weeks’ gestation in naturally conceived and uncomplicated pregnancies resulting in live births

2019 ◽  
Vol 57 (12) ◽  
pp. 1956-1967 ◽  
Author(s):  
Jesper Friis Petersen ◽  
Lennart J. Friis-Hansen ◽  
Andreas Kryger Jensen ◽  
Anders Nyboe Andersen ◽  
Ellen C.L. Løkkegaard
Keyword(s):  
Pregnant Women ◽  
Early Pregnancy ◽  
Clinical Chemistry ◽  
Clinical Care ◽  
Local Population ◽  
First Trimester ◽  
Reference Intervals ◽  
Specific Reference ◽  
Cancer Antigen 125 ◽  
Serum Samples

Abstract Background Pregnancy introduces major physiological changes that also alter biochemical analytes. Maternal and perinatal health can be optimized by early intervention and therefore, pregnancy-specific reference intervals (RIs) for the local population are warranted. While the second and third trimester-specific changes are well described, the first trimester is less well characterized. We therefore wanted to facilitate early detection of abnormalities by generating first trimester reference values for 29 common analytes. Methods In a prospective early pregnancy (PEP) cohort (2016–2017), 203 pregnant women were recruited from 4 to 8 weeks’ gestation. Consecutive blood samples were drawn every 2 weeks until an ongoing second trimester pregnancy (n = 164) or a miscarriage (n = 39) occurred. After exclusion of women with complicated pregnancies or deliveries (n = 42), 122 women were included. The serum samples collected at <6, 6–8, 8–10, 10–12 and >12 weeks’ gestation were analyzed for 29 common analytes. Subsequently the RIs were calculated according to the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendations (2.5–97.5th percentiles) and compared with the conventional RIs for non-pregnant women. Results Human chorionic gonadotropin (hCG), progesterone (P4), estradiol (E2), pregnancy-associated plasma protein A (PAPP-A), cancer antigen 125 (CA125), thyroid stimulating hormone (TSH), creatinine (CREA) and albumin (ALB) showed an early pregnancy-dependent change compared with conventional limits. For ALB the change was seen at 5.5 weeks’ gestation. Conclusions We report gestational age-specific RIs available from the early part of the first trimester applicable to everyday clinical care of pregnant women. Well-known alterations of RIs seen in later trimesters are also observed in the first.

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 ◽  
...  
Keyword(s):  
Cystatin C ◽  
Pediatric Population ◽  
Age Groups ◽  
Serum Markers ◽  
Reference Intervals ◽  
Specific Reference ◽  
Healthy Children ◽  
Serum Samples ◽  
Serum Cystatin C ◽  
Age And Sex

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.

Reference intervals and biological variation for kallikrein 6: influence of age and renal failure

2012 ◽  
Vol 50 (5) ◽  
Author(s):  
Eduardo Martínez-Morillo ◽  
Anastasia Diamandis ◽  
Eleftherios P. Diamandis
Keyword(s):  
Renal Failure ◽  
Significant Positive Correlation ◽  
Reference Interval ◽  
Serum Marker ◽  
Reference Intervals ◽  
Biological Variation ◽  
Serum Samples ◽  
Positive Correlation ◽  
Reference Change Value ◽  
Kallikrein 6

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.

Reference intervals for thyreotropin and thyroid hormones for healthy adults based on the NOBIDA material and determined using a Modular E170®

2008 ◽  
Vol 46 (9) ◽  
Author(s):  
Lennart Friis-Hansen ◽  
Linda Hilsted
Keyword(s):  
Thyroid Hormones ◽  
Reference Interval ◽  
Reference Intervals ◽  
Healthy Adults ◽  
Free Triiodothyronine ◽  
Thyroglobulin Antibodies ◽  
Men And Women ◽  
Blood Samples ◽  
Upper Limit

Abstract: The aim of the present study was to establish Nordic reference intervals for thyreotropin (TSH) and the thyroid hormones in heparinized plasma.: We used 489 heparinized blood samples, collected in the morning, from the Nordic NOBIDA reference material, from healthy adults without medication. TSH, thyroxine, free thyroxine, triiodothyronine, free triiodothyronine, and thyroglobulin antibodies (Tg-ab) were measured using assays for Roche Modular E170: The measured concentrations for the thyroid hormones, but not TSH, followed a Gaussian distribution. There were more TPO-ab and Tg-ab positive women than men. After exclusion of the TPO-ab and the Tg-ab positive individuals, the reference interval TSH was 0.64 (0.61–0.72) to 4.7 (4.4–5.0) mIU/L. The exclusion of these ab-positive samples also minimized the differences in TSH concentrations between the sexes and the different Nordic countries. For the thyroid hormones, there were only minor differences between the reference intervals between the Nordic populations and between men and women. These reference intervals were unaffected by removal of the TPO-ab and TG-ab positive samples.: The upper limit of the TSH reference interval in our study is high compared to some other recent reports. This could be due to blood sampling in the morning. Furthermore, the Roche platform gives slightly higher results than other platforms. The number and distribution of the samples in the NOBIDA material makes it suitable for the determination of hormone Nordic reference intervals.Clin Chem Lab Med 2008;46:1305–12.

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