fibrin and Communicable-Diseases

Pathogens have developed particular strategies to infect and invade their hosts. Amongst these strategies' figures the modulation of several components of the innate immune system participating in early host defenses, such as the coagulation and complement cascades, as well as the fibrinolytic system. The components of the coagulation cascade and the fibrinolytic system have been proposed to be interfered during host invasion and tissue migration of bacteria, fungi, protozoa, and more recently, helminths. One of the components that has been proposed to facilitate pathogen migration is plasminogen (Plg), a protein found in the host's plasma, which is activated into plasmin (Plm), a serine protease that degrades fibrin networks and promotes degradation of extracellular matrix (ECM), aiding maintenance of homeostasis. However, pathogens possess Plg-binding proteins that can activate it, therefore taking advantage of the fibrin degradation to facilitate establishment in their hosts. Emergence of Plg-binding proteins appears to have occurred in diverse infectious agents along evolutionary history of host-pathogen relationships. The goal of the present review is to list, summarize, and analyze different examples of Plg-binding proteins used by infectious agents to invade and establish in their hosts. Emphasis was placed on mechanisms used by helminth parasites, particularly taeniid cestodes, where enolase has been identified as a major Plg-binding and activating protein. A new picture is starting to arise about how this glycolytic enzyme could acquire an entirely new role as modulator of the innate immune system in the context of the host-parasite relationship.

Topics: Bacterial Proteins; Carrier Proteins; Communicable Diseases; Extracellular Matrix; Fibrin; Fibrinolysin; Fibrinolysis; Host-Pathogen Interactions; Humans; Immune Evasion; Immunity, Innate; Plasminogen; Proteolysis

Fibrin-related markers such as soluble fibrin (SF) and D-dimer are considered useful for the diagnosis of thrombosis. However, the evidence for diagnosis of thrombosis by fibrin-related markers is not well-established.. To evaluate the cutoff values of D-dimer and SF in the diagnosis of thrombosis.. Plasma concentrations of SF and D-dimer were measured in 784 inpatients suspected of having thrombosis between 1 August 2003 and 31 December 2004, and then correlated with thrombosis.. Plasma concentrations of D-dimer and SF were significantly higher in patients with disseminated intravascular coagulation (DIC), deep vein thrombosis (DVT) and cerebral thrombosis, compared with those in patients without thrombosis. When cutoff values of > 3.0 microg mL(-1) for D-dimer and > 6.0 microg mL(-1) for SF were used for the diagnosis, more than 50% of patients (with the exception of liver transplant patients and postoperative patients) had thrombosis. Receiver operating characteristic analysis showed that SF was more useful than D-dimer for the diagnosis of thrombosis (i.e. DVT and DIC). The cutoff value of D-dimer (7.87 microg mL(-1)) was the same for DVT and DIC, while that of SF was slightly lower for DVT (7.05 microg mL(-1)) than for DIC (8.60 microg mL(-1)). Our findings suggest that high levels of plasma fibrin-related markers reflect high risk for thrombosis.

Topics: Aged; Biomarkers; Bone Diseases; Communicable Diseases; Disseminated Intravascular Coagulation; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Intracranial Thrombosis; Male; Middle Aged; Neoplasms; Risk Factors; ROC Curve; Venous Thrombosis

Topics: Afibrinogenemia; Aging; Communicable Diseases; Fibrin; Fibrinogen; Fibrinolysis; Hepatitis; Hepatitis A; Humans