Current Practices When Reporting Quantitative Human Chorionic Gonadotropin Test Results

2020 ◽  
Vol 5 (5) ◽  
pp. 850-857 ◽  
Author(s):  
David G Grenache
Keyword(s):  
Chorionic Gonadotropin ◽  
Gestational Age ◽  
Human Chorionic Gonadotropin ◽  
Single Point ◽  
Reference Interval ◽  
Reference Intervals ◽  
Chronological Age ◽  
Specific Reference ◽  
Test Results ◽  
Reporting Practices

Abstract Background Quantitative human chorionic gonadotropin (hCG) tests are commonly used to determine a woman’s pregnancy status. Discrete results are evaluated and/or interpreted against a reference interval or cutoff. Reporting practices across laboratories have not been investigated. Methods A voluntary questionnaire was distributed to 6433 laboratories participating in a general chemistry proficiency testing survey. Results Responses were received from 3568 (55%) laboratories. Overall, 31% used a single reference cutoff, with 42% and 14% using values of 5.0 and 25.0 IU/L, respectively. In total, 68% of laboratories provided result interpretations, most frequently “negative” and “positive.” Reference intervals based on chronological age were offered by 9% of laboratories; 60% reported gestational age-based intervals. In addition, 25% provided male-specific reference intervals, with 2.0 IU/L being the most commonly used single-point cutoff. Only 12% of laboratories offered a separate, orderable test for hCG as a tumor marker, with 5.0 IU/L as the most frequently used reference threshold. Nearly half of laboratories used assay product insert data as the reference interval source. Conclusions There is wide variation when reporting quantitative hCG results. Despite a well-established reference limit of <5.0 IU/L for nonpregnant women, fewer than half of laboratories used this cutoff. The reporting of gestational age-based reference intervals is more common than those based on chronological age despite greater clinical utility for the latter. Data-driven guidelines for reporting quantitative hCG test results could deliver more consistent result interpretation.

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.

scholarly journals Effect of 1 mg/kg oral prednisolone on biochemical analytes in ten dogs: a cross-over study

2021 ◽  
Author(s):  
Helena Pettersson ◽  
Carl Ekstrand ◽  
Anna Hillström ◽  
Inger Lilliehöök
Keyword(s):  
Clinical Relevance ◽  
Control Period ◽  
Iron Concentration ◽  
Oral Prednisolone ◽  
Reference Intervals ◽  
Specific Reference ◽  
Test Results ◽  
Prednisolone Treatment ◽  
Anti Inflammatory ◽  
And Control

AbstractPrednisolone is used for treatment of inflammatory, allergic, neoplastic, and immune-mediated diseases in dogs. As a glucocorticoid, prednisolone has biochemical effects, which may interfere with the interpretation of biochemistry test results. The aim of this study is to investigate the effects of prednisolone treatment in an anti-inflammatory dose on common biochemical analytes in dogs and to evaluate the clinical relevance of the changes. Ten beagle dogs, enrolled in a cross-over study, were treated with oral prednisolone (1 mg/kg 24 h) for 10 days. Blood samples were collected at day 0, 1, 3, 6, 9, 10, 12, 16, and 20. Data was analyzed using a general linear model with time and treatment as fixed factors. Pairwise comparisons were done between prednisolone and control period for each dog and sampling. Significant results were further evaluated for clinical relevance using laboratory-specific reference intervals and reference change values (RCVs), when available. Statistically significant changes were observed for ALP activity and iron concentration, which increased to levels exceeding the RCV, and several results were outside reference intervals. Phosphate and bile acids increased significantly, while amylase, lipase, and cholesterol decreased significantly, but with mean/median results remaining within reference intervals. Anti-inflammatory prednisolone treatment did not induce significant changes in ALT, GLDH, GGT, cPLI, glucose, or calcium. Treatment with an anti-inflammatory dose of prednisolone induced changes in several analytes. Only the increases in ALP and iron were of such magnitude that they are expected to affect the clinical interpretation of test results.

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.

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.

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 Personalized Reference Intervals in Laboratory Medicine: A New Model Based on Within-Subject Biological Variation

2020 ◽  
Author(s):  
Abdurrahman Coşkun ◽  
Sverre Sandberg ◽  
Ibrahim Unsal ◽  
Coskun Cavusoglu ◽  
Mustafa Serteser ◽  
...  
Keyword(s):  
Steady State ◽  
Personalized Medicine ◽  
Clinical Chemistry ◽  
Reference Interval ◽  
Reference Intervals ◽  
Biological Variation ◽  
Test Results ◽  
Steady State Condition ◽  
Laboratory Test Results ◽  
Measurement Results

Abstract Background The concept of personalized medicine has received widespread attention in the last decade. However, personalized medicine depends on correct diagnosis and monitoring of patients, for which personalized reference intervals for laboratory tests may be beneficial. In this study, we propose a simple model to generate personalized reference intervals based on historical, previously analyzed results, and data on analytical and within-subject biological variation. Methods A model using estimates of analytical and within-subject biological variation and previous test results was developed. We modeled the effect of adding an increasing number of measurement results on the estimation of the personal reference interval. We then used laboratory test results from 784 adult patients (&gt;18 years) considered to be in a steady-state condition to calculate personalized reference intervals for 27 commonly requested clinical chemistry and hematology measurands. Results Increasing the number of measurements had little impact on the total variation around the true homeostatic set point and using ≥3 previous measurement results delivered robust personalized reference intervals. The personalized reference intervals of the study participants were different from one another and, as expected, located within the common reference interval. However, in general they made up only a small proportion of the population-based reference interval. Conclusions Our study shows that, if using results from patients in steady state, only a few previous test results and reliable estimates of within-subject biological variation are required to calculate personalized reference intervals. This may be highly valuable for diagnosing patients as well as for follow-up and treatment.

Gestational age-specific reference intervals for 15 biochemical measurands during normal pregnancy in China

2017 ◽  
Vol 55 (4) ◽  
pp. 446-452 ◽  
Author(s):  
Yanpeng Dai ◽  
Junjie Liu ◽  
Enwu Yuan ◽  
Yushan Li ◽  
Quanxian Wang ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Gestational Age ◽  
Parametric Method ◽  
First Trimester ◽  
Normal Pregnancy ◽  
Reference Intervals ◽  
Specific Reference ◽  
Gamma Glutamyl Transpeptidase ◽  
Cross Sectional ◽  
Laboratory Results

Aims Physiological changes that occur during pregnancy can influence biochemical parameters. Therefore, using reference intervals based on specimens from non-pregnant women to interpret laboratory results during pregnancy may be inappropriate. This study aimed to establish the essential reference intervals for a range of analytes during pregnancy. Methods A cross-sectional study was performed in 13,656 healthy pregnant and 2634 non-pregnant women. Fifteen biochemical measurands relating to renal and hepatic function were analysed using an Olympus AU5400 analyzer (Olympus, Tokyo, Japan). All the laboratory results were checked for outliers using Dixon’s test. Reference intervals were established using a non-parametric method. Results Alanine aminotransferase, aspartate aminotransferase, albumin, cholinesterase, creatinine, direct bilirubin, gamma-glutamyl transpeptidase, total bilirubin, total bile acid and total protein showed a decrease during the whole gestational period, while alkaline phosphatase and uric acid increased. Urea nitrogen, β2-microglobulin and cystatin-C fell significantly during the first trimester and then remained relatively stable until third trimester. Reference intervals of all the measurands during normal pregnancy have been established. Conclusions The reference intervals established here can be adopted in other clinical laboratories after appropriate validation. We verified the importance, for some measurands, of partitioning by gestational age when establishing reference intervals during pregnancy.

Prediction of Smallness for Gestational Age by Maternal Serum Human Chorionic Gonadotropin Levels and by Uterine Artery Doppler Study

2000 ◽  
Vol 16 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Kei Miyakoshi ◽  
Mamoru Tanaka ◽  
Danilo Gabionza ◽  
Hitoshi Ishimoto ◽  
Toyohiko Miyazaki ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Gestational Age ◽  
Human Chorionic Gonadotropin ◽  
Uterine Artery ◽  
Maternal Serum ◽  
Uterine Artery Doppler ◽  
Doppler Study
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