What is DIC pathogenesis?
Disseminated intravascular coagulation (DIC) is an acquired clinicobiological syndrome characterized by widespread activation of coagulation leading to fibrin deposition in the vasculature, organ dysfunction, consumption of clotting factors and platelets, and life-threatening hemorrhage.
What pathogen causes DIC?
DIC is classically associated with Gram negative bacterial infections but it can occur with a similar incidence in Gram positive sepsis. Moreover, systemic infections with other micro-organisms, such as viruses, Rickettsiae and even parasites (e.g. Plasmodium falciparum) may also result in DIC.
What causes DIC syndrome?
DIC is usually caused by inflammation from an infection, injury, or illness. Some common causes include: Sepsis: This is a body-wide response to infection that causes inflammation. Sepsis is the most common risk factor for DIC.
What are the pathologic findings of DIC?
Laboratory findings suggestive of DIC include a low platelet count, elevated D-dimer concentration, decreased fibrinogen concentration, and prolongation of clotting times such as prothrombin time (PT).
How does endotoxin cause DIC?
Excessive activation of the coagulation system by endotoxin leads to life- threatening disseminated intravascular coagulation (DIC).
Why does amniotic fluid embolism cause DIC?
Amniotic fluid embolism syndrome (AFES) is another complication of pregnancy. 80% of individuals with AFE develop DIC [3]. AFES occurs when there is a breach between maternal and fetal compartments, resulting in amniotic fluid entrance into maternal circulation. This can result in death [4].
Why do platelets decrease in DIC?
The decreased platelet count in DIC is due to excessive thrombin activation and is almost always less than 100 × 109/L and often trending down.
What happens to platelets in DIC?
DIC is a syndrome involving the activation of coagulation, resulting in the intravascular deposition of fibrin and the consumption of coagulation proteins and platelets, which commonly leads to bleeding. DIC can lead to organ dysfunction and is associated with high mortality rates.
How does DIC affect platelets?
Patients with DIC have a low or rapidly decreasing platelet count, prolonged global coagulation tests, low plasma levels of coagulation factors and inhibitors, and increased markers of fibrin formation and/or degradation, such as D-dimer or fibrin degradation products.
How does inflammation cause DIC?
When you are injured, proteins in the blood that form blood clots travel to the injury site to help stop bleeding. If these proteins become abnormally active throughout the body, you could develop DIC. The underlying cause is usually due to inflammation, infection, or cancer.
Can amniotic fluid cause DIC?
DIC has been reported to occur in approximately 80% of patients with amniotic fluid embolism syndrome and may ultimately be the principle cause of death.
Why is PT and aPTT increased in DIC?
PROTHROMBIN TIME AND ACTIVATED PARTIAL THROMBOPLASTIN TIME Both PT and aPTT seem prolonged in about 50% of DIC cases which is attributed to the consumption of coagulation factors but can also be prolonged in impaired synthesis of coagulation factors and in massive bleeding.
What does fibrinogen do in DIC?
Fibrinogen is an acute phase reactant and its plasma level can remain elevated for prolonged periods despite ongoing consumption in DIC. Hence, hypofibrinogenaemia for diagnosis of DIC carries very low sensitivity and was associated only with severe forms of DIC.
How does TNF alpha cause DIC?
TNF-α increases the expression of tissue factor on surfaces of both monocytes and endothelial cells and decreases the anticoagulant potential of endothelial cells, thereby inducing intravascular coagulation.
How does TNF cause DIC?
Tumor necrosis factor (TNF) and interleukin 8 (IL-8) increase the inflammatory response, while IL-10 inhibits it. IL-1 beta, IL-12, IL-2, G-CSF, and IFN-gamma have all been reported to induce coagulation. IL-4, IL-13, and TGF-beta have anticoagulant activity. These imbalances all promote the development of DIC.
Why does preeclampsia cause DIC?
While in developing countries preeclampsia and the HELLP syndrome are prevalent causes of DIC, the leading causes in the developed countries are placental abruption and postpartum hemorrhage. In different cohort studies, DIC is reported in about 12-14% of women with preeclampsia.
How DIC occurs in preeclampsia?
The process of DIC is initiated through the activation of tissue factor (TF), which is found in subendothelial cells, amniotic fluid, and placenta. DIC is seen in severe forms of preeclampsia with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome.