Development of enzyme-linked immunosorbent assay for acidic fibroblast growth factor and its clinical application.

We have developed, for the first time, an enzyme-linked immunosorbent assay (ELISA) system for the measurement of human acidic fibroblast growth factor (aFGF). Anti-bovine aFGF rabbit IgG was conjugated with N-hydroxysuccimidobiotin, and the resulting IgG-biotin conjugate was used as the second antibody. This assay was highly specific and reproducible, enabling us to detect aFGF at a concentration as low as 1 microg/l without any prior processing of samples. With this method, it was possible to determine human aFGF up to 833 x 10(3) ng/l, with the use of anti-bovine aFGF IgG as the first and second antibody. There was no significant cross-reactivity of the antibody with other growth factors, such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF). The aFGF concentration in pericardial fluid was significantly higher in patients with unstable angina than in those with other heart diseases, suggesting that the aFGF plays an important role(s) in the course of collateral growth in coronary artery disease. Therefore, our ELISA system may be useful in determining unknown biological function(s) or pathological role(s) of aFGF in various disease entities.