[Studies on the blood coagulation factor XIII in patients with increased levels of FDP D-dimer]

Antigen levels of blood coagulation factor XIII (XIII) were determined in plasmas from patients with increased levels of fibrin degradation products-D-dimer (FDP-DD), including disseminated intravascular coagulation (DIC), by latex photometric immunoassay using polyclonal anti-XIII a subunit antibody-coated latex reagent. Since stable fibrin is directly degradated by plasmin and FDP-DD is produced, plasma FDP-DD levels correlate with plasmin-alpha 2-plasmin inhibitor complex levels, but not with thrombin-antithrombin III complex (TAT) or XIII levels. In order to clarify other causes of discordant relationships among the related three parameters, we studied the changes in plasma XIII, TAT and FDP-DD levels in fourteen DIC patients induced by various primary disorders. Only in two cases, XIII levels changed up and down irrelevant to the fluctuating levels of TAT and FDP-DD. In seven cases, plasma XIII levels remained low during the clinical courses, indicating possibilities that elevated condition of XIII consumption continued and/or production of XIII was low. On the other hand, in four patients, including two patients with nephrosis, XIII might be produced at higher rate than that of consumption. Same phenomenon was observed in one of eight recipients with living-related liver transplantation who showed remarkably increased levels of FDP-DD without DIC. In conclusion, plasma XIII level in patients with elevated FDP-DD may be influenced by the balance between consumption of XIII by unstable fibrin and/or surgical stress and the following tissue recovery etc. and production of XIII in liver, megakaryocytes and monocytes.