The invention provides nonspecific antibodies which are specifically reactive with the .alpha..sub.E subunit of fibrinogen or a fragment thereof, but not with other portions of the fibrinogen molecule. The invention also provides anti-.alpha..sub.E probes, including nonspecific anti-.alpha..sub.E antibodies which have been detectably labeled. In addition, the invention provides methods of using the nonspecific antibodies for detection of the .alpha..sub.E subunit and fragments thereof, as well as reagents and kits for performing the methods. Diagnostic methods for determining information associated with atherogenesis and/or thrombogenesis, as well as for determining information associated with pregnancy status or outcome. The invention further provides continuous cell lines which produce monospecific anti-.alpha..sub.E antibodies.