MyMedR

Fulltext Evaluation of the performance of a micromethod for measuring urinary iodine by using six sigma quality metrics

Hussain H, Khalid NM, Selamat R, Wan Nazaimoon WM

Ann Lab Med, 2013 Sep;33(5):319-25.

PMID: 24003421 DOI: 10.3343/alm.2013.33.5.319

BACKGROUND: The urinary iodine micromethod (UIMM) is a modification of the conventional method and its performance needs evaluation.
METHODS: UIMM performance was evaluated using the method validation and 2008 Iodine Deficiency Disorders survey data obtained from four urinary iodine (UI) laboratories. Method acceptability tests and Sigma quality metrics were determined using total allowable errors (TEas) set by two external quality assurance (EQA) providers.
RESULTS: UIMM obeyed various method acceptability test criteria with some discrepancies at low concentrations. Method validation data calculated against the UI Quality Program (TUIQP) TEas showed that the Sigma metrics were at 2.75, 1.80, and 3.80 for 51±15.50 µg/L, 108±32.40 µg/L, and 149±38.60 µg/L UI, respectively. External quality control (EQC) data showed that the performance of the laboratories was within Sigma metrics of 0.85-1.12, 1.57-4.36, and 1.46-4.98 at 46.91±7.05 µg/L, 135.14±13.53 µg/L, and 238.58±17.90 µg/L, respectively. No laboratory showed a calculated total error (TEcalc)

Fulltext Total 25-OH vitamin D concentrations in Chinese, Malays and Indians

Hawkins R

Ann Lab Med, 2013 Mar;33(2):156-8.

PMID: 23479565 DOI: 10.3343/alm.2013.33.2.156

Fulltext Human Platelet Antigen Datasets for Malays, Chinese, and Indians in Peninsular Malaysia

Hajar CGN, Zefarina Z, Md Riffin NS, Mohammad THT, Hassan MN, Dafalla AM, et al.

Ann Lab Med, 2020 11;40(6):493-499.

PMID: 32539307 DOI: 10.3343/alm.2020.40.6.493

Fulltext Erratum: Human Platelet Antigen Datasets for Malays, Chinese, and Indians in Peninsular Malaysia

Ann Lab Med, 2021 01;41(1):128.

PMID: 32829591 DOI: 10.3343/alm.2021.41.1.128

[This corrects the article on p. 493 in vol. 40.].

Fulltext Multi-center Performance Evaluations of Tacrolimus and Cyclosporine Electrochemiluminescence Immunoassays in the Asia-Pacific Region

Qin X, Rui J, Xia Y, Mu H, Song SH, Raja Aziddin RE, et al.

Ann Lab Med, 2018 Mar;38(2):85-94.

PMID: 29214751 DOI: 10.3343/alm.2018.38.2.85

BACKGROUND: The immunosuppressant drugs (ISDs), tacrolimus and cyclosporine, are vital for solid organ transplant patients to prevent rejection. However, toxicity is a concern, and absorption is highly variable across patients; therefore, ISD levels need to be precisely monitored. In the Asia-Pacific (APAC) region, tacrolimus and cyclosporine concentrations are typically measured using immunoassays. The objective of this study was to assess the analytical performance of Roche Elecsystacrolimus and cyclosporinee electrochemiluminescence immunoassays (ECLIAs).

METHODS: This evaluation was performed in seven centers across China, South Korea, and Malaysia. Imprecision (repeatability and reproducibility), assay accuracy, and lot-to-lot reagent variability were tested. The Elecsys ECLIAs were compared with commercially available immunoassays (Architect, Dimension, and Viva-E systems) using whole blood samples from patients with various transplant types (kidney, liver, heart, and bone marrow).

RESULTS: Coefficients of variation for repeatability and reproducibility were ≤5.4% and ≤12.4%, respectively, for the tacrolimus ECLIA, and ≤5.1% and ≤7.3%, respectively, for the cyclosporine ECLIA. Method comparisons of the tacrolimus ECLIA with Architect, Dimension, and Viva-E systems yielded slope values of 1.01, 1.14, and 0.897, respectively. The cyclosporine ECLIA showed even closer agreements with the Architect, Dimension, and Viva-E systems (slope values of 1.04, 1.04, and 1.09, respectively). No major differences were observed among the different transplant types.

CONCLUSIONS: The tacrolimus and cyclosporine ECLIAs demonstrated excellent precision and close agreement with other immunoassays tested. These results show that both assays are suitable for ISD monitoring in an APAC population across a range of different transplant types.

Fulltext The Use of Bone-Turnover Markers in Asia-Pacific Populations

Vasikaran S, Thambiah SC, Tan RZ, Loh TP, APFCB Harmonization of Reference Interval Working Group

Ann Lab Med, 2024 Mar 01;44(2):126-134.

PMID: 37869778 DOI: 10.3343/alm.2023.0214

Bone-turnover marker (BTM) measurements in the blood or urine reflect the bone-remodeling rate and may be useful for studying and clinically managing metabolic bone diseases. Substantial evidence supporting the diagnostic use of BTMs has accumulated in recent years, together with the publication of several guidelines. Most clinical trials and observational and reference-interval studies have been performed in the Northern Hemisphere and have mainly involved Caucasian populations. This review focuses on the available data for populations from the Asia-Pacific region and offers guidance for using BTMs as diagnostic biomarkers in these populations. The procollagen I N-terminal propeptide and β-isomerized C-terminal telopeptide of type-I collagen (measured in plasma) are reference BTMs used for investigating osteoporosis in clinical settings. Premenopausal reference intervals (established for use with Asia-Pacific populations) and reference change values and treatment targets (used to monitor osteoporosis treatment) help guide the management of osteoporosis. Measuring BTMs that are not affected by renal failure, such as the bone-specific isoenzyme alkaline phosphatase and tartrate-resistant acid phosphatase 5b, may be advantageous for patients with advanced chronic kidney disease. Further studies of the use of BTMs in individuals with metabolic bone disease, coupled with the harmonization of commercial assays to provide equivalent results, will further enhance their clinical applications.

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