P143	The plasmatic homocysteine increase alters tisular plasminogen activator and plasminogen activator INHIBITOR-1 relationship in patients suffering from homocistinuria.
A.Córdoba Porras, L.A.Villa Lopez
University of Antioquía, Medellín, CO.

OBJECTIVE. To determine whether the homocysteine (Hcy) increment in the blood alters the tPA/PAI-1 antigens, in patients suffering from homocystinuria. SUMMARY. The moderate or severe increase of Hcy in the blood or fibrinolitic system alterations are associated with vascular disease. Patients sufferings from homocistinuria (HC) often also suffer from thromboembolic events, and these are the main cause of mortality. However, the mechanisms through which Hcy promotes these events are not yet determined. ANALYSED POPULATION. Ten patients suffering from classic HC were analysed, (Ages 20.5±3 years. 5 men and 5 women). All responsive to pyridoxine treatment. And eleven healthy controls (Ages 21±2.5 years. 5 men and 6 women). All of them were residents in the city of Medellin, Colombia. Hcy was determined by means of fluorescence polarization immunoassay. tPA and PAI-1 antigens were determined using TintElize® tPA and TintElize® PAI-1 Biopool Kits respectively. RESULTS. Both Hcy (228±30 μmoles/L) and PAI-1 antigen (75.7±16.4 ng/mL) plasmatic concentration were significantly increased in the patients compared to the controls (p<0.0001; p<0.0001, respectively) (Hcy: 7.1±1.5 μmoles/L PAI-1: 8.8±2.8 ng/mL). tPA antigen was found to be lightly increased in the patients (p>0.09; 5.4±1.7 vs 4.2±1.4 ng/mL). tPA/PAI-1 relationship in the patients was significantly reduced compared with the healthy controls (p<0.0001; 0.0713 patients vs 0.477 controls). CONCLUSION: Severe increase of Hcy, significantly diminishes the tPA/PAI-1 antigens relationship. This alteration could be involved in the thromboembolic events etiology.

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