Open AccessHarmonization of serum 25‐hydroxycalciferol assay results from high‐performance liquid chromatography, enzyme immunoassay, radioimmunoassay, and immunochemiluminescence systems: A multicenter study
Author(s) -
Nikooyeh Bahareh,
Samiee Siamak M.,
Farzami Marjan R.,
Alavimajd Hamid,
Zahedirad Maliheh,
Kalayi Ali,
Shariatzadeh Nastaran,
Boroumand Nasrin,
Golshekan Elham,
Gholamian Yalda,
Neyestani Tirang R.
Publication year - 2017
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.22117
Subject(s) - radioimmunoassay , immunoassay , chromatography , high performance liquid chromatography , vitamin d and neurology , chemistry , medicine , immunology , antibody , biochemistry
Background Remarkable disagreement among different systems of 25‐hydroxy vitamin D 25( OH )D assay makes decision making for both clinical and community interventions very difficult. This study aimed to harmonize the results obtained from different 25( OH )D assay systems. Methods A total of 275 serum samples were analyzed for 25( OH )D using DIA source‐enzyme immunoassay ( EIA ), DIA source‐radioimmunoassay ( RIA ), Roche‐electrochemiluminescence ( ECL ), Diasorin‐chemiluminescent immunoassay ( CLIA ), and high‐performance liquid chromatography ( HPLC ), as the reference method. Serum intact parathyroid hormone ( iPTH ) was also measured in all samples. Between‐system agreement and harmonization were evaluated using Bland–Altman analysis, receiver operating characteristic ( ROC ), and regression analysis. Results Mean serum 25( OH )D concentrations and frequency distribution of vitamin D status showed a significant difference among the studied systems ( P <.001 for both). Serum 25( OH )D assay results from all systems correlated with those from HPLC . As compared with HPLC , ECL showed a positive bias (+3.8 nmol/L), whereas CLIA had a negative bias (−11.9 nmol/L). Both EIA and RIA showed a more or less similar positive bias (8.0 and 8.1 nmol/L, respectively). Using serum iPTH ‐based 25( OH )D cutoff points, only ECL results became comparable to and without significant difference with HPLC . However, when system‐specific cutoffs were defined based on HPLC results using regression equations, mean 25( OH )D and frequency distribution of vitamin D status were more harmonized compared with the other methods. Conclusion Our findings showed that with adjustment of circulating 25( OH )D based on HPLC , frequency distribution of vitamin D status, as judged by different methods, can be well harmonized with no statistically significant inter‐system difference.