Performance characteristics of a simple radioimmunoassay for fibrinopeptide A.

FPA, although identified 15 years ago, is now becoming an increasingly important diagnostic tool in the evaluation of the hemostatic process. Since this peptide is generated in very small amounts, only very sensitive methods, such as RIA, are useful for its quantitation. Measurement of this peptide allows for a most precise and reliable monitor of any ongoing thrombotic event in which thrombin is generated. Commercial kits have become available for fast and simple clinical evaluations of FPA. The Mallinckrodt RIA Quanti FPA kit has proved its reliability in precision, accuracy, fast turnaround time, and applicability to a routine laboratory setting. This assay kit was evaluated in our laboratory in various aspects. The following points summarize our finding: FPA is a useful diagnostic parameter to evaluate the activation of coagulation pathways in various pathologic states. A study of 170 normal plasma samples resulted in 1.7 +/- 0.5 ng/ml. No significant difference between males and females was noted. FPA levels are evaluated in patients with hypercoagulable states, DIC, and related thrombotic states. Our studies have shown that FPA levels are also elevated in certain cancers, postsurgical states, and certain other conditions in which the coagulation process is activated. During therapeutic heparinization, FPA levels are reduced; thus this form of therapy can be monitored using FPA levels. High-risk population (thrombotic) can be easily screened using FPA measurement. We propose that a multicenter study on FPA levels be conducted to prove its clinical relevance to other diseases.(ABSTRACT TRUNCATED AT 250 WORDS)