G. N. Drannik, Ya. M. Yena, T. V. Varetskaya. Products of fibrin/fibrinogen cleavage in pathological processes (biochemical and clinical aspects). Kiev, Zdorov'ya, 1987.

One of the biochemical indicators objectively characterizing the state of hemostasis is the level of fibrin and fibrinogen cleavage products in blood, which are formed, as a rule, as a result of intravascular fibrin formation with simultaneous or subsequent activation of fibrinolytic system, accompanied by appearance of proteolytic enzyme plasmin. Plasmin splits (degrades) the formed fibrin or (to a lesser extent) fibrinogen, which leads to the appearance of more or less large protein "fragments" in the bloodstream, called products of fibrin degradation. Some of them are unable to clot and can be detected in serum after clot separation. Thus, the detection of fibrin degradation products always indicates intravascular activation of hemocoagulation and fibrinolysis systems.