We studied a possible effect of the extent of the acute
phase response after acute myocardial infarction on
the cumulative release of troponin T. The height of the
acute phase response might influence the cumulative
release of troponin T, bound to the myofibrillar structures
of the heart, in a different way compared to the
free cytoplasmic cardiac marker hydroxybutyrate dehydrogenase
(EC 184.108.40.206). To investigate this, the cumulative
amount of C-reactive protein in plasma, i.e.
the quantified acute phase response, was related to
the cumulative plasma release of hydroxybutyrate dehydrogenase
(an established method for infarct sizing)
on the one hand and to that of troponin T on the other
The study was performed in patients receiving
(n=16) and in patients not receiving (n=6) thrombolytic
therapy. Cumulative protein release was calculated using
a two-compartment model for circulating proteins.
Conclusions: The cumulative amount of plasma C-reactive
protein is significantly higher in the patients
not receiving thrombolytic therapy, as is in accordance
with earlier studies. The cumulative amount of troponin
T released is significantly related to the cumulated
concentration of C-reactive protein, especially in
patients not receiving thrombolytic therapy. The intensity
of the acute phase response, estimated from cumulative
plasma C-reactive protein response, has no
effect on the relative proportions of troponin T and hydroxybutyrate
dehydrogenase released into plasma.
Tissue factor, the main initiator of blood coagulation, is shed into plasma by blood cells and endothelium. While studying such circulating plasma tissue factor with a commercially available immunoassay, we found unsatisfactory results and therefore developed a new and highly sensitive enzyme-linked immunosorbent assay (ELISA). High-affinity monoclonal antibodies raised against recombinant soluble tissue factor were used and the new assay had a detection limit of 40fmol/L, approximately six-fold lower than existing assays. Normal ranges in 20 healthy donors were established in serum and in citrated EDTA and heparinized plasma. Tissue factor was also measured in three successive plasma samples from 43 patients with type 2 diabetes mellitus. In citrated plasma from healthy donors, tissue factor concentrations were 2.5 (1.0–9.3) pmol/L (median with range) and were not significantly different in diabetics. With a commercially available immunoassay, seven plasma samples were below the detection limit. Use of the new assay reduced intra-individual variation in diabetics from 49% to 14% and we conclude that high-affinity antibodies may markedly improve immunoassay performance.