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25OHD analogues and vacuum blood collection tubes dramatically affect the accuracy of automated immunoassays.

Yu S, Cheng X, Fang H, Zhang R, Han J, Qin X, Cheng Q, Su W, Hou L, Xia L, Qiu L - Sci Rep (2015)

Bottom Line: However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator.Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives.Bias decreased and clinical agreement improved significantly when using tubes with no additives.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.

ABSTRACT
Variations in vitamin D quantification methods are large, and influences of vitamin D analogues and blood collection methods have not been systematically examined. We evaluated the effects of vitamin D analogues 25OHD2 and 3-epi 25OHD3 and blood collection methods on vitamin D measurement, using five immunoassay systems and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum samples (332) were selected from routine vitamin D assay requests, including samples with or without 25OHD2 or 3-epi 25OHD3, and analysed using various immunoassay systems. In samples with no 25OHD2 or 3-epi 25OHD3, all immunoassays correlated well with LC-MS/MS. However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator. When 25OHD2 or 3-epi 25OHD3 was present, correlations and clinical agreement decreased for all immunoassays. Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives. Bias decreased and clinical agreement improved significantly when using tubes with no additives. In conclusion, most automated immunoassays showed acceptable correlation and agreement with LC-MS/MS; however, 25OHD analogues and blood collection tubes dramatically affected accuracy.

No MeSH data available.


Bias between 25OHD results in VACUETTE 4-mL tubes with gel and clot activator and in VACUETTE 4-mL additive-free tubes of each method.X-axis: sample numbers; Y-axis: 25OHD results in VACUETTE 4-mL tubes with gel and clot activator minus 25OHD results in VACUETTE 4-mL additive-free tubes.
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f3: Bias between 25OHD results in VACUETTE 4-mL tubes with gel and clot activator and in VACUETTE 4-mL additive-free tubes of each method.X-axis: sample numbers; Y-axis: 25OHD results in VACUETTE 4-mL tubes with gel and clot activator minus 25OHD results in VACUETTE 4-mL additive-free tubes.

Mentions: Next, to clarify whether the vacuum blood collection tubes affected the accuracy of immunoassays, we analysed 10 samples after blood collection into both VACUETTE 4-mL additive-free tubes and VACUETTE 4-mL tubes with gel and clot activator, and analyzed all samples by the five immunoassays and LC-MS/MS. Results was shown as Fig. 3, and it was shown that samples collected in VACUETTE 4-mL tubes with gel and clot activator exhibited apparently higher values than samples in tubes with no additives (mean bias (SD): 12.7 (4.3) ng/mL, P < 0.01) using the Siemens system. An additional 67 volunteers were recruited and their serum was collected in VACUETTE 4-mL additive-free tubes, and for the total 77 samples collected in VACUETTE 4-mL additive-free tubes were all analyzed both by Siemens system and LC-MS/MS, and the correlation coefficient between the two methods improved, bias decreased significantly, and with a slope close to 1, indicated agreement (Kappa = 0.68) (Fig. 4).


25OHD analogues and vacuum blood collection tubes dramatically affect the accuracy of automated immunoassays.

Yu S, Cheng X, Fang H, Zhang R, Han J, Qin X, Cheng Q, Su W, Hou L, Xia L, Qiu L - Sci Rep (2015)

Bias between 25OHD results in VACUETTE 4-mL tubes with gel and clot activator and in VACUETTE 4-mL additive-free tubes of each method.X-axis: sample numbers; Y-axis: 25OHD results in VACUETTE 4-mL tubes with gel and clot activator minus 25OHD results in VACUETTE 4-mL additive-free tubes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588576&req=5

f3: Bias between 25OHD results in VACUETTE 4-mL tubes with gel and clot activator and in VACUETTE 4-mL additive-free tubes of each method.X-axis: sample numbers; Y-axis: 25OHD results in VACUETTE 4-mL tubes with gel and clot activator minus 25OHD results in VACUETTE 4-mL additive-free tubes.
Mentions: Next, to clarify whether the vacuum blood collection tubes affected the accuracy of immunoassays, we analysed 10 samples after blood collection into both VACUETTE 4-mL additive-free tubes and VACUETTE 4-mL tubes with gel and clot activator, and analyzed all samples by the five immunoassays and LC-MS/MS. Results was shown as Fig. 3, and it was shown that samples collected in VACUETTE 4-mL tubes with gel and clot activator exhibited apparently higher values than samples in tubes with no additives (mean bias (SD): 12.7 (4.3) ng/mL, P < 0.01) using the Siemens system. An additional 67 volunteers were recruited and their serum was collected in VACUETTE 4-mL additive-free tubes, and for the total 77 samples collected in VACUETTE 4-mL additive-free tubes were all analyzed both by Siemens system and LC-MS/MS, and the correlation coefficient between the two methods improved, bias decreased significantly, and with a slope close to 1, indicated agreement (Kappa = 0.68) (Fig. 4).

Bottom Line: However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator.Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives.Bias decreased and clinical agreement improved significantly when using tubes with no additives.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.

ABSTRACT
Variations in vitamin D quantification methods are large, and influences of vitamin D analogues and blood collection methods have not been systematically examined. We evaluated the effects of vitamin D analogues 25OHD2 and 3-epi 25OHD3 and blood collection methods on vitamin D measurement, using five immunoassay systems and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum samples (332) were selected from routine vitamin D assay requests, including samples with or without 25OHD2 or 3-epi 25OHD3, and analysed using various immunoassay systems. In samples with no 25OHD2 or 3-epi 25OHD3, all immunoassays correlated well with LC-MS/MS. However, the Siemens system produced a large positive mean bias of 12.5 ng/mL and a poor Kappa value when using tubes with clot activator and gel separator. When 25OHD2 or 3-epi 25OHD3 was present, correlations and clinical agreement decreased for all immunoassays. Serum 25OHD in VACUETTE tubes with gel and clot activator, as measured by the Siemens system, produced significantly higher values than did samples collected in VACUETTE tubes with no additives. Bias decreased and clinical agreement improved significantly when using tubes with no additives. In conclusion, most automated immunoassays showed acceptable correlation and agreement with LC-MS/MS; however, 25OHD analogues and blood collection tubes dramatically affected accuracy.

No MeSH data available.