Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays

Hiroshi Ihara, Toshiaki Watanabe, Naotaka Hashizume, Masayuki Totani, Kazuyuki Kamioka, Kimiko Onda, Satoshi Sunahara, Tomoko Suzuki, Mitsuharu Itabashi, Yoshikazu Aoki, Midori Ishibashi, Shozo Ito, Koji Ohashi, Tsuyoshi Enomoto, Kensuke Saito, Kayoko Saeki, Yoichi Nagamura, Tsutomu Nobori, Kouichi Hirota, Kinya FujishiroMasato Maekawa, Masakazu Miura, Yoshiji Ohta

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Background: The aim of the present study was to evaluate standard reference material (SRM) 1955 commutability as a reference material for serum folate using automated methods. We also designed so as to reduce the intermethod variability present in different automated methods. Methods: Using a microbiological assay related to the 'information value' of SRM 1955 as a comparison method, we investigated the possibility of standardization for the assay values of serum folate as measured by the automated methods (Access, Centaur and Elecsys). In the assay of 50 patient sera by these automated methods, we corrected observed values by the SRM 1955 and compared with comparison values. Results: The observed values of SRM 1955 Levels I, II and III were within or outside (but near) a 95% prediction interval obtained from patient sera by the automated methods. The normalized residuals obtained from SRM 1955 were within ± 3.0 (in SD units), which enabled us to conclude that the SRM 1955 had a physicochemical characterization similar to native serum. Twelve patients were assessed as hypofolataemia (<6.0 ng/mL) and 38 patients as normal (≥6.0 ng/mL). Before correction, folate levels in six of 12 patients were lower than 6.0 ng/mL, and those in seven of 38 patients were higher than 6.0 ng/mL with the automated methods. After correction, low levels were found in four of 12 patients, and normal levels were found in 33 of 38 patients. Conclusions: The use of SRM 1955 would help to reduce the intermethod variability present in different automated methods for serum folate measurement.

Original languageEnglish
Pages (from-to)541-548
Number of pages8
JournalAnnals of Clinical Biochemistry
Volume47
Issue number6
DOIs
Publication statusPublished - 01-11-2010

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Homocysteine
Folic Acid
Assays
Technology
Serum
Reference Values
Standardization

All Science Journal Classification (ASJC) codes

  • Clinical Biochemistry

Cite this

Ihara, Hiroshi ; Watanabe, Toshiaki ; Hashizume, Naotaka ; Totani, Masayuki ; Kamioka, Kazuyuki ; Onda, Kimiko ; Sunahara, Satoshi ; Suzuki, Tomoko ; Itabashi, Mitsuharu ; Aoki, Yoshikazu ; Ishibashi, Midori ; Ito, Shozo ; Ohashi, Koji ; Enomoto, Tsuyoshi ; Saito, Kensuke ; Saeki, Kayoko ; Nagamura, Yoichi ; Nobori, Tsutomu ; Hirota, Kouichi ; Fujishiro, Kinya ; Maekawa, Masato ; Miura, Masakazu ; Ohta, Yoshiji. / Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays. In: Annals of Clinical Biochemistry. 2010 ; Vol. 47, No. 6. pp. 541-548.
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title = "Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays",
abstract = "Background: The aim of the present study was to evaluate standard reference material (SRM) 1955 commutability as a reference material for serum folate using automated methods. We also designed so as to reduce the intermethod variability present in different automated methods. Methods: Using a microbiological assay related to the 'information value' of SRM 1955 as a comparison method, we investigated the possibility of standardization for the assay values of serum folate as measured by the automated methods (Access, Centaur and Elecsys). In the assay of 50 patient sera by these automated methods, we corrected observed values by the SRM 1955 and compared with comparison values. Results: The observed values of SRM 1955 Levels I, II and III were within or outside (but near) a 95{\%} prediction interval obtained from patient sera by the automated methods. The normalized residuals obtained from SRM 1955 were within ± 3.0 (in SD units), which enabled us to conclude that the SRM 1955 had a physicochemical characterization similar to native serum. Twelve patients were assessed as hypofolataemia (<6.0 ng/mL) and 38 patients as normal (≥6.0 ng/mL). Before correction, folate levels in six of 12 patients were lower than 6.0 ng/mL, and those in seven of 38 patients were higher than 6.0 ng/mL with the automated methods. After correction, low levels were found in four of 12 patients, and normal levels were found in 33 of 38 patients. Conclusions: The use of SRM 1955 would help to reduce the intermethod variability present in different automated methods for serum folate measurement.",
author = "Hiroshi Ihara and Toshiaki Watanabe and Naotaka Hashizume and Masayuki Totani and Kazuyuki Kamioka and Kimiko Onda and Satoshi Sunahara and Tomoko Suzuki and Mitsuharu Itabashi and Yoshikazu Aoki and Midori Ishibashi and Shozo Ito and Koji Ohashi and Tsuyoshi Enomoto and Kensuke Saito and Kayoko Saeki and Yoichi Nagamura and Tsutomu Nobori and Kouichi Hirota and Kinya Fujishiro and Masato Maekawa and Masakazu Miura and Yoshiji Ohta",
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Ihara, H, Watanabe, T, Hashizume, N, Totani, M, Kamioka, K, Onda, K, Sunahara, S, Suzuki, T, Itabashi, M, Aoki, Y, Ishibashi, M, Ito, S, Ohashi, K, Enomoto, T, Saito, K, Saeki, K, Nagamura, Y, Nobori, T, Hirota, K, Fujishiro, K, Maekawa, M, Miura, M & Ohta, Y 2010, 'Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays', Annals of Clinical Biochemistry, vol. 47, no. 6, pp. 541-548. https://doi.org/10.1258/acb.2010.010094

Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays. / Ihara, Hiroshi; Watanabe, Toshiaki; Hashizume, Naotaka; Totani, Masayuki; Kamioka, Kazuyuki; Onda, Kimiko; Sunahara, Satoshi; Suzuki, Tomoko; Itabashi, Mitsuharu; Aoki, Yoshikazu; Ishibashi, Midori; Ito, Shozo; Ohashi, Koji; Enomoto, Tsuyoshi; Saito, Kensuke; Saeki, Kayoko; Nagamura, Yoichi; Nobori, Tsutomu; Hirota, Kouichi; Fujishiro, Kinya; Maekawa, Masato; Miura, Masakazu; Ohta, Yoshiji.

In: Annals of Clinical Biochemistry, Vol. 47, No. 6, 01.11.2010, p. 541-548.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Commutability of National Institute of Standards and Technology standard reference material 1955 homocysteine and folate in frozen human serum for total folate with automated assays

AU - Ihara, Hiroshi

AU - Watanabe, Toshiaki

AU - Hashizume, Naotaka

AU - Totani, Masayuki

AU - Kamioka, Kazuyuki

AU - Onda, Kimiko

AU - Sunahara, Satoshi

AU - Suzuki, Tomoko

AU - Itabashi, Mitsuharu

AU - Aoki, Yoshikazu

AU - Ishibashi, Midori

AU - Ito, Shozo

AU - Ohashi, Koji

AU - Enomoto, Tsuyoshi

AU - Saito, Kensuke

AU - Saeki, Kayoko

AU - Nagamura, Yoichi

AU - Nobori, Tsutomu

AU - Hirota, Kouichi

AU - Fujishiro, Kinya

AU - Maekawa, Masato

AU - Miura, Masakazu

AU - Ohta, Yoshiji

PY - 2010/11/1

Y1 - 2010/11/1

N2 - Background: The aim of the present study was to evaluate standard reference material (SRM) 1955 commutability as a reference material for serum folate using automated methods. We also designed so as to reduce the intermethod variability present in different automated methods. Methods: Using a microbiological assay related to the 'information value' of SRM 1955 as a comparison method, we investigated the possibility of standardization for the assay values of serum folate as measured by the automated methods (Access, Centaur and Elecsys). In the assay of 50 patient sera by these automated methods, we corrected observed values by the SRM 1955 and compared with comparison values. Results: The observed values of SRM 1955 Levels I, II and III were within or outside (but near) a 95% prediction interval obtained from patient sera by the automated methods. The normalized residuals obtained from SRM 1955 were within ± 3.0 (in SD units), which enabled us to conclude that the SRM 1955 had a physicochemical characterization similar to native serum. Twelve patients were assessed as hypofolataemia (<6.0 ng/mL) and 38 patients as normal (≥6.0 ng/mL). Before correction, folate levels in six of 12 patients were lower than 6.0 ng/mL, and those in seven of 38 patients were higher than 6.0 ng/mL with the automated methods. After correction, low levels were found in four of 12 patients, and normal levels were found in 33 of 38 patients. Conclusions: The use of SRM 1955 would help to reduce the intermethod variability present in different automated methods for serum folate measurement.

AB - Background: The aim of the present study was to evaluate standard reference material (SRM) 1955 commutability as a reference material for serum folate using automated methods. We also designed so as to reduce the intermethod variability present in different automated methods. Methods: Using a microbiological assay related to the 'information value' of SRM 1955 as a comparison method, we investigated the possibility of standardization for the assay values of serum folate as measured by the automated methods (Access, Centaur and Elecsys). In the assay of 50 patient sera by these automated methods, we corrected observed values by the SRM 1955 and compared with comparison values. Results: The observed values of SRM 1955 Levels I, II and III were within or outside (but near) a 95% prediction interval obtained from patient sera by the automated methods. The normalized residuals obtained from SRM 1955 were within ± 3.0 (in SD units), which enabled us to conclude that the SRM 1955 had a physicochemical characterization similar to native serum. Twelve patients were assessed as hypofolataemia (<6.0 ng/mL) and 38 patients as normal (≥6.0 ng/mL). Before correction, folate levels in six of 12 patients were lower than 6.0 ng/mL, and those in seven of 38 patients were higher than 6.0 ng/mL with the automated methods. After correction, low levels were found in four of 12 patients, and normal levels were found in 33 of 38 patients. Conclusions: The use of SRM 1955 would help to reduce the intermethod variability present in different automated methods for serum folate measurement.

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U2 - 10.1258/acb.2010.010094

DO - 10.1258/acb.2010.010094

M3 - Article

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VL - 47

SP - 541

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JO - Annals of Clinical Biochemistry

JF - Annals of Clinical Biochemistry

SN - 0004-5632

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