Fibrin profiles

Alteplase was the first commercially available recombinant tissue-type plasminogen activator (rt-PA) (25), It has a plasma half-life of less than five minutes and is metabolized by the liver, This agent was initially hailed as fibrin-specific unlike its precursors (urokinase and streptokinase). It was thought that this would result in a better safety profile, but this has not been born out in either the coronary or the peripheral experience, where actually there may be a higher bleeding risk as infusion time increases. Alteplase is currently indicated for use in the treatment of myocardial infarction, acute ischemic stroke, and pulmonary embolism. 

The thrombotic response to uncoated PVC and to uncoated Silastic would be expected to be identical if thrombosis is surface nonspecific or if the surfaces initially adsorb the same proportion of the various plasma proteins that influence thrombosis. Comparisons of the responses of the uncoated surfaces (Figure 2 with 5 and 3 with 6) reveal that both the fibrin(ogen) and platelet deposition profiles on uncoated Silastic were significantly different than those on PVC. Fibrin(ogen) deposition proceeded at a slower rate on uncoated Silastic than on uncoated PVC, and peaked after 30 min of blood... 

Lipoprotein(a) is essentially an LDL particle that is covalently bound to apoprotein) a). It is called lipoprotein little a to avoid confusion with the apoprotein A found in HDL. The structure of apoprotein(a) is very similar to that of plasminogen, a precursor of the protease plasmin that degrades fibrin, a major component of blood clots. Lipoprotein(a), however, cannot be converted to active plasmin. There are reports that high concentrations of lipoprotein(a) correlate with an increased risk of coronary artery disease, even in patients in whom the lipid profile is otherwise normal. 

M4. Makowski, G. S., and Ramsby, M. L., Interaction of amorphous calcium phosphate with fibrin in vitro causes decreased fibrinolysis and altered protease profiles Implications for atherosclerotic disease. Inflammation 25, 319-329 (2001). 

Fairbrother, J.E. (1995) A global publication profile of fibrin sealants. Thromb. Haemost., 73, 1470a. 

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