Open AccessEffect of elevated concentration of alkaline phosphatase on cardiac troponin I assays
Author(s) -
Dasgupta Amitava,
Chow Leonard,
Wells Alice,
Datta Pradip
Publication year - 2001
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.1023
Subject(s) - troponin i , immunoassay , cardiac marker , chemistry , alkaline phosphatase , troponin , chemiluminescence , microbiology and biotechnology , myocardial infarction , enzyme , biochemistry , chromatography , medicine , immunology , biology , antibody
Troponin I is the regulatory subunit of troponin complex associated with the actin thin filament within muscle cells. Cardiac troponin I (cTnI) is a good marker for diagnosis of myocardial damage. Several immunoassays are available for determination of cTnI in serum. The Stratus cTnI fluorometric enzyme immunoassay (Dade International) uses alkaline phosphatase (ALP) substrate. The microparticle enzyme immunoassay (MEIA) for cTnI (Abbott Laboratories) also uses ALP conjugate. On the other hand, the chemiluminescent assay (CLIA) for cTnI (Bayer Diagnostics) does not use ALP. ALP activity may frequently be elevated in serum of patients being evaluated for suspected myocardial infarction. Therefore, we studied the potential interference of ALP in cTnI assays. Serum pools were prepared from patients, and various concentrations of ALP solution were added to different aliquots. The cTnI concentrations were measured by the Stratus, MEIA, and CLIA assays. We observed no interference of ALP in the MEIA and CLIA assay for cTnI. On the other hand, we observed significant positive interference of ALP when cTnI concentrations were measured using the Stratus. J. Clin. Lab. Anal. 15:175–177, 2001. © 2001 Wiley‐Liss, Inc.