Target Cells Are NOT a Finding of Disseminated Intravascular Coagulation
The correct answer is d. target cells—these are NOT associated with DIC. Target cells are morphologic red blood cell abnormalities seen in conditions such as liver disease, thalassemia, hemoglobinopathies, and post-splenectomy states, but they are not part of the DIC laboratory picture. 1, 2
Classic Laboratory Findings in DIC
The hallmark laboratory abnormalities in DIC reflect the underlying pathophysiology of consumptive coagulopathy and microangiopathic hemolysis:
Thrombocytopenia (Option a - IS a finding)
- Platelet consumption from widespread intravascular clotting is a characteristic and essential laboratory finding in DIC. 1, 2
- Thrombocytopenia occurs in approximately 75% of DIC patients and represents the most common laboratory abnormality. 3
- Even a 30% or greater drop in platelet count from baseline is diagnostic of subclinical DIC, even when absolute values remain within normal range. 2
Hypofibrinogenemia/Fibrinogenopenia (Option b - IS a finding)
- Decreased fibrinogen levels develop in advanced DIC cases due to consumption of coagulation factors. 1, 2
- While fibrinogen may initially be normal or even elevated as an acute phase reactant early in the disease process, progressive consumption leads to hypofibrinogenemia. 1
- Low fibrinogen is one of the core components of the ISTH DIC diagnostic scoring system. 3, 2
Fibrin/Fibrinogen Degradation Products (Option c - IS a finding)
- Elevated fibrin-related markers (D-dimer and fibrin degradation products) indicating ongoing fibrin formation and breakdown are characteristic laboratory findings in DIC. 1, 2
- These markers reflect the simultaneous activation of coagulation and fibrinolysis that defines DIC pathophysiology. 3
- D-dimer is highly sensitive for DIC diagnosis and is included in all major DIC scoring systems. 3, 2
Schistocytes (Option e - IS a finding)
- Schistocytes (fragmented red blood cells) are frequently observed in DIC patients, resulting from mechanical shearing of red blood cells as they pass through fibrin strands in the microvasculature. 4, 5
- Schistocytes were present in 30 of 35 DIC patients (86%) in one study, though typically at low percentages (mean 0.33%, median 0.1%). 4
- While the percentage is usually low and within or close to reference range (<0.5%), schistocytes ≥1% suggest an associated thrombotic microangiopathy. 4
- The presence of schistocytes reflects microangiopathic hemolysis, which is part of the consumptive process in DIC. 6, 5
Why Target Cells Don't Fit
Target cells represent a fundamentally different pathophysiologic process—they are morphologic abnormalities related to altered hemoglobin distribution or membrane lipid composition, not mechanical fragmentation or consumption. They have no role in the diagnosis or monitoring of DIC and would not be expected in this condition unless there is a concurrent unrelated disorder (such as underlying liver disease). 3