Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Standard

Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum. / Kakonen, S M; Hellman, J; Karp, M; Laaksonen, P; Obrant, Karl; Vaananen, H K; Lovgren, T; Pettersson, K.

I: Clinical Chemistry, Vol. 46, Nr. 3, 2000, s. 332-337.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

Kakonen, SM, Hellman, J, Karp, M, Laaksonen, P, Obrant, K, Vaananen, HK, Lovgren, T & Pettersson, K 2000, 'Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum', Clinical Chemistry, vol. 46, nr. 3, s. 332-337. <http://www.clinchem.org/cgi/content/abstract/46/3/332>

APA

Kakonen, S. M., Hellman, J., Karp, M., Laaksonen, P., Obrant, K., Vaananen, H. K., Lovgren, T., & Pettersson, K. (2000). Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum. Clinical Chemistry, 46(3), 332-337. http://www.clinchem.org/cgi/content/abstract/46/3/332

CBE

Kakonen SM, Hellman J, Karp M, Laaksonen P, Obrant K, Vaananen HK, Lovgren T, Pettersson K. 2000. Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum. Clinical Chemistry. 46(3):332-337.

MLA

Vancouver

Kakonen SM, Hellman J, Karp M, Laaksonen P, Obrant K, Vaananen HK et al. Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum. Clinical Chemistry. 2000;46(3):332-337.

Author

Kakonen, S M ; Hellman, J ; Karp, M ; Laaksonen, P ; Obrant, Karl ; Vaananen, H K ; Lovgren, T ; Pettersson, K. / Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum. I: Clinical Chemistry. 2000 ; Vol. 46, Nr. 3. s. 332-337.

RIS

TY - JOUR

T1 - Development and evaluation of three immunofluorometric assays that measure different forms of osteocalcin in serum

AU - Kakonen, S M

AU - Hellman, J

AU - Karp, M

AU - Laaksonen, P

AU - Obrant, Karl

AU - Vaananen, H K

AU - Lovgren, T

AU - Pettersson, K

PY - 2000

Y1 - 2000

N2 - BACKGROUND: Circulating human osteocalcin (hOC) has been used as a marker of bone formation. Our aim was to validate three immunofluorometric assays (IFMAs), measuring different forms of hOC. METHODS: The two-site IFMAs were based on previously characterized monoclonal antibodies. Assay 2 recognized intact hOC, assays 4 and 9 measured the NH(2)-terminal mid-fragment and the intact hOC. In addition, assay 9 required hOC to be gamma-carboxylated. RESULTS: A 76-79% increase of serum immunoreactive hOC was found in the postmenopausal group compared with the premenopausal group with all IFMAs. With EDTA-plasma samples, the observed increases were lower (49-65%). The hOC concentration in the postmenopausal group receiving hormone replacement therapy was 42-44% lower than that in the postmenopausal control group in both serum and EDTA-plasma samples. The depressed carboxylation in warfarin-treated patients was accompanied by lower results in assay 9. The ratio of assay 9 to assay 4 totally discriminated the warfarin-treated patients from the controls. Assay 9 showed the smallest decreases in measured hOC after storage of serum or plasma for 4 weeks at 4 degrees C, followed by assay 4 and assay 2. Results from the last assay were <17% of their initial values after 4 weeks of storage. No diurnal variation was observed with assay 9 as opposed to the two other IFMAs. CONCLUSION: The three assays with their distinct specificity profiles (intact vs fragmented and carboxylated vs decarboxylated hOC) may provide valuable tools for investigating the significance of different hOC forms in various bone-related diseases.

AB - BACKGROUND: Circulating human osteocalcin (hOC) has been used as a marker of bone formation. Our aim was to validate three immunofluorometric assays (IFMAs), measuring different forms of hOC. METHODS: The two-site IFMAs were based on previously characterized monoclonal antibodies. Assay 2 recognized intact hOC, assays 4 and 9 measured the NH(2)-terminal mid-fragment and the intact hOC. In addition, assay 9 required hOC to be gamma-carboxylated. RESULTS: A 76-79% increase of serum immunoreactive hOC was found in the postmenopausal group compared with the premenopausal group with all IFMAs. With EDTA-plasma samples, the observed increases were lower (49-65%). The hOC concentration in the postmenopausal group receiving hormone replacement therapy was 42-44% lower than that in the postmenopausal control group in both serum and EDTA-plasma samples. The depressed carboxylation in warfarin-treated patients was accompanied by lower results in assay 9. The ratio of assay 9 to assay 4 totally discriminated the warfarin-treated patients from the controls. Assay 9 showed the smallest decreases in measured hOC after storage of serum or plasma for 4 weeks at 4 degrees C, followed by assay 4 and assay 2. Results from the last assay were <17% of their initial values after 4 weeks of storage. No diurnal variation was observed with assay 9 as opposed to the two other IFMAs. CONCLUSION: The three assays with their distinct specificity profiles (intact vs fragmented and carboxylated vs decarboxylated hOC) may provide valuable tools for investigating the significance of different hOC forms in various bone-related diseases.

M3 - Article

VL - 46

SP - 332

EP - 337

JO - Clinical Chemistry

JF - Clinical Chemistry

SN - 0009-9147

IS - 3

ER -