scholarly journals Division of Myocardial Enzyme Reference Intervals in Population Aged 1 to <18 Years Old Based on Fisher’s Optimal Segmentation Method

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Wenjia Guo ◽  
Qi Zhou ◽  
Yanan Jia ◽  
Jiancheng Xu
Keyword(s):  
Creatine Kinase ◽  
Cardiac Development ◽  
Reference Interval ◽  
Reference Intervals ◽  
Impact Factors ◽  
Segmentation Method ◽  
Splitting Sequence ◽  
Biochemical Analyzer ◽  
Optimal Segmentation ◽  
Ordered Data

Background. Reference interval (RI) research is to make it a concise, effective, and practical diagnostic tool. This study aimed to establish sex- and age-specific RI for myocardial enzyme activity in population aged 1–<18 years old in Changchun, China. Methods. Healthy subjects (n = 6,322, 1–<18 years old) were recruited from communities and schools. Aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase isoenzyme (CKMB) were measured using an automatic biochemical analyzer. Fisher’s optimal segmentation method was used to partition by including percentiles as impact factors, aiming at minimizing the sum of the squares of the total dispersion into groups as splitting sequence of ordered data. Results. AST decreased gradually and was partitioned as 1, 2∼<10 and 10∼<18 years old. LDH presented disparate descending rate among 1∼<4, 4∼<12, and 12∼<18 years old. CK stood quite stable with the same RI in all ages. CKMB began to differ at 6 years of age sexually and then remained stable during 6∼<14 years old for male while it continued to decline in female. Cardiac development was partitioned as 1∼<6, 6∼<13, and 13∼<18 years old using multiple percentiles from massive data that reflect characteristics of totality as impact factors. Conclusions. Fisher’s optimal segmentation method excelled for multidimensionality, continuity, and loop calculating as dealing with RIs for myocardial enzymes activity and cardiac development process despite limitations. In future, impact of partition on the overall interval should be delved into.

Are the currently used reference intervals for creatine kinase (CK) reflecting the general population? The Tromsø Study

2012 ◽  
Vol 50 (5) ◽  
Author(s):  
Hallvard Lilleng ◽  
Stein Harald Johnsen ◽  
Tom Wilsgaard ◽  
Svein Ivar Bekkelund
Keyword(s):  
Creatine Kinase ◽  
General Population ◽  
Reference Interval ◽  
Reference Intervals ◽  
Control Analysis ◽  
Age Group ◽  
Background Population ◽  
Norwegian Population ◽  
Reference Limits ◽  
Laboratory Reference

AbstractLaboratory reference intervals are not necessarily reflecting the range in the background population. This study compared creatine kinase (CK) reference intervals calculated from a large sample from a Norwegian population with those elaborated by the Nordic Reference Interval Project (NORIP). It also assessed the pattern of CK-normalization after standardized control analyses.New upper reference limits (URL) CK values were calculated after exclusion of individuals with risk of hyperCKemia and including individuals with incidentally detected hyperCKemia after they had completed a standardized control analysis. After exclusion of 5924 individuals with possible causes of hyperCKemia, CK samples were analyzed in 6904 individuals participating in the 6th survey of The Tromsø Study. URL was defined as the 97.5 percentile.New URL in women was 207 U/L. In men <50 years it was 395 U/L and in men ≥50 years 340 U/L. In individuals with elevated CK, normalization grade after control analysis was inversely correlated to the CK level (p<0.04).URL CK values in women and in men <50 years of age were in accordance with URL CK values given by the NORIP. In men ≥50 years, a higher URL was found and the findings suggest an upward adjustment of URL in this age group.

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 Reference values of plasma homocysteine in Cuban children and adults

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Alina Concepción Alvarez ◽  
Ivette Camayd Viera ◽  
Lisy Vento Buigues ◽  
Yanet Fernández Martínez ◽  
Eraida Hernández ◽  
...  
Keyword(s):  
Reference Values ◽  
High Performance ◽  
Age Groups ◽  
Coffee Consumption ◽  
Reference Interval ◽  
Reference Intervals ◽  
Multifactorial Diseases ◽  
Weak Association ◽  
Different Populations ◽  
Cuban Population

AbstractObjectivesHomocysteine (Hcy) is a nonessential amino acid, produced by the demethylation of methionine. High Hcy levels, or hyperhomocysteinemia, have been associated with genetic and multifactorial diseases. Hcy reference values may vary between different populations, as Hcy levels are affected by factors such as sex, age, diet, smoking, and coffee consumption. The estimation reference interval (RI) allows to establish the normal values of this marker in population. At present, these levels are unknown in Cuba. The aim of this work is to estimate the Hcy reference intervals in Cuban children and adults.MethodsTotal Hcy concentration was quantified by high performance liquid chromatography (HPLC) in plasma. Hcy levels were evaluated in samples from 507 healthy individuals (260 children, 247 adults).ResultsRIs were estimated by nonparametric methods. We found significant differences between both age groups, but we did not find significant differences between sexes, within these groups. The established ranges were 2.56–14.55 µM and 3.63–17.19 µM for children and adults, respectively. Also, we observed a weak association between Hcy levels and age in both sex groups.ConclusionsThis is the first study that assesses Hcy reference values in Cuban population. Our results will allow the introduction of Hcy as a biochemical marker in laboratory testing.

Reference intervals for venous blood gas measurement in adults

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kirsty L. Ress ◽  
Gus Koerbin ◽  
Ling Li ◽  
Douglas Chesher ◽  
Phillip Bwititi ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Meta Analysis ◽  
Venous Blood ◽  
Reference Interval ◽  
Reference Intervals ◽  
Published Data ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Venous Blood Gas

AbstractObjectivesVenous blood gas (VBG) analysis is becoming a popular alternative to arterial blood gas (ABG) analysis due to reduced risk of complications at phlebotomy and ease of draw. In lack of published data, this study aimed to establish reference intervals (RI) for correct interpretation of VBG results.MethodsOne hundred and 51 adult volunteers (101 females, 50 males 18–70 y), were enrolled after completion of a health questionnaire. Venous blood was drawn into safePICO syringes and analysed on ABL827 blood gas analyser (Radiometer Pacific Pty. Ltd.). A non-parametric approach was used to directly establish the VBG RI which was compared to a calculated VBG RI based on a meta-analysis of differences between ABG and VBGResultsAfter exclusions, 134 results were used to derive VBG RI: pH 7.30–7.43, partial pressure of carbon dioxide (pCO2) 38–58 mmHg, partial pressure of oxygen (pO2) 19–65 mmHg, bicarbonate (HCO3−) 22–30 mmol/L, sodium 135–143 mmol/L, potassium 3.6–4.5 mmol/L, chloride 101–110 mmol/L, ionised calcium 1.14–1.29 mmol/L, lactate 0.4–2.2 mmol/L, base excess (BE) −1.9–4.5 mmol/L, saturated oxygen (sO2) 23–93%, carboxyhaemoglobin 0.4–1.4% and methaemoglobin 0.3–0.9%. The meta-analysis revealed differences between ABG and VBG for pH, HCO3−, pCO2 and pO2 of 0.032, −1.0 mmol/L, −4.2 and 39.9 mmHg, respectively. Using this data along with established ABG RI, calculated VBG RI of pH 7.32–7.42, HCO3− 23 – 27 mmol/L, pCO2 36–49 mmHg (Female), pCO2 39–52 mmHg (Male) and pO2 43–68 mmHg were formulated and compared to the VBG RI of this study.ConclusionsAn adult reference interval has been established to assist interpretation of VBG results.

scholarly journals Experience with the Urinary Tetrasaccharide Metabolite for Pompe Disease in the Diagnostic Laboratory

Metabolites ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 446
Author(s):  
Jennifer T. Saville ◽  
Maria Fuller
Keyword(s):  
Pompe Disease ◽  
Late Onset ◽  
Reference Interval ◽  
Laboratory Diagnosis ◽  
Reference Intervals ◽  
Confirmatory Test ◽  
Diagnostic Laboratory ◽  
Age Related ◽  
Initial Drop ◽  
Monitoring Treatment

Following clinical indications, the laboratory diagnosis of the inherited metabolic myopathy, Pompe disease (PD), typically begins with demonstrating a reduction in acid alpha-glucosidase (GAA), the enzyme required for lysosomal glycogen degradation. Although simple in concept, a major challenge is defining reference intervals, as even carriers can have reduced GAA, and pseudodeficiencies complicate interpretation. Here, we developed a mass spectrometric assay for quantification of a urinary glycogen metabolite (tetrasaccharide) and reported on its utility as a confirmatory test for PD in a diagnostic laboratory. Using two age-related reference intervals, eight returned tetrasaccharide concentrations above the calculated reference interval but did not have PD, highlighting non-specificity. However, retrospective analysis revealed elevated tetrasaccharide in seven infantile-onset (IOPD) cases and sixteen late-onset (LOPD) cases, and normal concentrations in one heterozygote. Prospective tetrasaccharide analysis in nine individuals with reduced GAA confirmed IOPD in one, LOPD in six and identified two heterozygotes. Using this metabolite as a biomarker of therapeutic response was not overly informative; although most patients showed an initial drop following therapy initiation, tetrasaccharide concentrations fluctuated considerably and remained above reference intervals in all patients. While useful as a confirmation of PD, its utility as a biomarker for monitoring treatment warrants further investigation.

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.

scholarly journals Reference intervals for hematology test parameters from apparently healthy individuals in southwest Ethiopia

2018 ◽  
Vol 6 ◽  
pp. 205031211880762 ◽  
Author(s):  
Lealem Gedefaw Bimerew ◽  
Tesfaye Demie ◽  
Kaleab Eskinder ◽  
Aklilu Getachew ◽  
Shiferaw Bekele ◽  
...  
Keyword(s):  
Platelet Count ◽  
Blood Cell ◽  
White Blood Cell ◽  
Red Blood Cell ◽  
Hematological Parameters ◽  
Age Groups ◽  
Reference Interval ◽  
Reference Intervals ◽  
Southwest Ethiopia ◽  
Apparently Healthy

Background: Clinical laboratory reference intervals are an important tool to identify abnormal laboratory test results. The generating of hematological parameters reference intervals for local population is very crucial to improve quality of health care, which otherwise may lead to unnecessary expenditure or denying care for the needy. There are no well-established reference intervals for hematological parameters in southwest Ethiopia. Objective: To generate hematological parameters reference intervals for apparently healthy individuals in southwest Ethiopia. Methods: A community-based cross-sectional study was conducted involving 883 individuals from March to May 2017. Four milliliter of blood sample was collected and transported to Jimma University Medical Center Laboratory for hematological analysis and screening tests. A hematological parameters were measured by Sysmex XS-500i hematology analyzer (Sysmex Corporation Kobe, Japan). The data were analyzed by SPSS version 20 statistical software. The non-parametric independent Kruskal–Wallis test and Wilcoxon rank-sum test (Mann–Whitney U test) were used to compare the parameters between age groups and genders. The 97.5 percentile and 2.5 percentile were the upper and lower reference limit for the population. Results: The reference interval of red blood cell, white blood cell, and platelet count in children were 4.99 × 1012/L (4.26–5.99 × 1012/L), 7.04 × 109/L (4.00–11.67 × 109/L), and 324.00 × 109/L (188.00–463.50 × 109/L), respectively. The reference interval of red blood cell, white blood cell, and platelet count in adults was 5.19 × 1012/L (4.08–6.33 × 1012/L), 6.35 × 109/L (3.28–11.22 × 109/L), and 282.00 × 109/L (172.50–415.25 × 109/L), respectively. The reference interval of red blood cell, white blood cell, and platelet count in geriatrics were 5.02 × 1012/L (4.21–5.87 × 1012/L), 6.21 × 109/L (3.33–10.03 × 109/L), and 265.50 × 109/L (165.53–418.80 × 109/L), respectively. Most of the hematological parameters showed significant differences across all age groups. Conclusion: Most of the hematological parameters in this study showed differences from similar studies done in the country. This study provided population-specific hematological reference interval for southwest Ethiopians. Reference intervals should also be established in the other regions of the country.

ESTABLISHING IN-HOUSE REFERENCE INTERVALS FOR DOGS IN VETERINARY CLINICS

2016 ◽  
Vol 42 (02) ◽  
pp. 53-67
Author(s):  
Shang-Hsiu Chung ◽  
Li-Wen Chang ◽  
Tsun-Li Cheng ◽  
Chen-Jou Lin ◽  
Wen-Ying Chen ◽  
...  
Keyword(s):  
Uric Acid ◽  
Bile Acid ◽  
Biochemical Parameters ◽  
Clinical Pathology ◽  
Reference Interval ◽  
Reference Intervals ◽  
Gamma Glutamyl Transferase ◽  
Coagulation Parameters ◽  
American Society ◽  
Glutamyl Transferase

Reference interval (RIs) were critical to the identification of illness. However, RIs set in one laboratory may not be appropriate for another because of biological, geographical and instrumental factors. Interpretation of clinical data using inappropriate RIs may cause misclassification of results and misdiagnosis that lead to improper treatment. RIs in Taiwan have been mostly referencing from foreign resources, it is desirable to establish one that is closer to the overall conditions in Taiwan (such as breed, climate, diseases, etc.) and to investigate its differences to foreign RIs. The present study used the American Society for Veterinary Clinical Pathology (ASVCP) guidelines to establish in-house RIs for hematological, biochemical and coagulation parameters using dogs in middle Taiwan. The results were also compared to two foreign and one local RIs. The results suggested that the hematological RIs are more comparable to foreign RIs than the biochemical and hemostatic parameters. Differences were found for biochemical parameters including gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), lipase, uric acid, bile acid, bilirubin and magnesium; and coagulation parameters including prothrombin time (PT) and activated partial thromboplastin. In all, 18% (7/40) of the all tested parameters were different from the local RI while 38% (18/48) and 41% (19/46) of the parameters were different from the two foreign RIs. The differences in more than 30% RIs and better similarities to local RIs underscore the importance of having own RIs if possible.

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