Which laboratory profile is most characteristic of DIC?

Which laboratory profile is most characteristic of DIC?

• A. Decreased platelets, prolonged PT and PTT, low fibrinogen, and elevated D-dimer.
• B. Thrombocytosis, shortened PT and PTT, normal fibrinogen, and normal D-dimer.
• C. Normal platelets, prolonged PT only, high fibrinogen, and normal D-dimer.
• D. Decreased platelets, normal PT/PTT, normal fibrinogen, and normal D-dimer.

Answer: (C)

DIC is a consumption coagulopathy where widespread clotting uses up platelets and coagulation factors while fibrinolysis increases to break down those clots. The lab pattern that fits this scenario shows low platelets, prolonged coagulation times (PT and PTT), low fibrinogen from consumption, and a high D-dimer from fibrin degradation. This combination—thrombocytopenia plus prolonged PT/PTT, reduced fibrinogen, and elevated D-dimer—best reflects the ongoing coagulation and fibrinolysis of DIC. An alternative pattern with normal platelets, only prolonged PT, high fibrinogen, and normal D-dimer does not align with DIC, because there is no platelet consumption, no broad depletion of coagulation factors, and no increased fibrin breakdown product production.

DIC is a consumption coagulopathy where widespread clotting uses up platelets and coagulation factors while fibrinolysis increases to break down those clots. The lab pattern that fits this scenario shows low platelets, prolonged coagulation times (PT and PTT), low fibrinogen from consumption, and a high D-dimer from fibrin degradation. This combination—thrombocytopenia plus prolonged PT/PTT, reduced fibrinogen, and elevated D-dimer—best reflects the ongoing coagulation and fibrinolysis of DIC.

An alternative pattern with normal platelets, only prolonged PT, high fibrinogen, and normal D-dimer does not align with DIC, because there is no platelet consumption, no broad depletion of coagulation factors, and no increased fibrin breakdown product production.