Summary
We have devised a simple enzyme immunoassay to detect and quantitate autoantibodies
against derivatives of fibrinogen. This assay has been applied with a range of antigens
including a fibrinogen lysate (containing X, Y, D and E), D dimer, D dimerE and a
preparation of high molecular weight complexes derived from crosslinked fibrin. We
have found that autoantibodies interacting with these antigens can be detected in
varying concentrations in most sera from both normal subjects and patients with a
variety of diseases and are evidently of mixed Ig class. These autoantibodies are
directed against at least several cryptic antigens which appear during fibrinogen/fibrin
degradation and some appear to be directed specifically against cross- linked fibrin
derivatives. No clear disease correlates have yet emerged but a relationship between
elevated levels and prior infective, thrombotic, inflammatory or traumatic disorders
is likely. It is suggested that these autoantibodies may contribute to the catabolism
of fibrinogen derivatives, provide a marker of thrombosis, and sometimes produce pathologic
effects.
Key words
Fibrin(ogen) degradation products - Autoimmunity - Intravascular coagulation - Enzyme-linked
immunoassay
