Platelet aggregation and physiological anticoagulants in sickle-cell disease

During the period January 2002- December 2004, we assessed 30 sickle- cell anaemia patients admitted to hospital in Al Khobar with vaso- occlusive crisis for levels of antithrombin [AT] III, protein C [PC] and protein S [PS]. We also did platelet aggregation studies. Steady state levels were assessed during follow- up and compared with 36 adult controls. Levels of PC, PS and AT III in the group were significantly higher than in those in vaso- occlusive crisis and those in steady state control [P < 0.001]. There was a statistically significant difference between controls and patients for all platelet factors except adrenaline. There was no significant difference between the levels of PC, PS, aggregation AT III and platelet aggregation variables in patients in the steady state and in vaso- occlusive crisi

Antithrombin III, heparin cofactor II and histidine-rich glycoprotein in patients with pulmonary embolism

In seventy-two patients hospitalized for clinical suspicion of pulmonary embolism [PE], level of antithrombin III [AT III], heparin cofactor II [HC II] and histidine-rich glycoprotein [HRGP] were determined. Forty-four patients were positive for PE and twenty-nine received standard heparin. HC II and HRGP did not show any statistically significant variation between patients who were positive or negative for PE. Moreover, presence or absence of heparin therapy in these patients did not modify the level of these two proteins. In contrast, AT III showed a statistically significant reduction in PE than non-PE. Since AT III is one of the most powerful inhibitors against serine protease enzymes of coagulation cascade, it is possible that low levels in patients with PE could be considered as the expression of consumption to prevent further thrombus formation

Effect of hemodialysis on protein C and antithrombin III

The effect of hemodialysis on natural coagulation inhibitors including protein C [PC] and antithrombin III [AT III] had been studied. Plasma PC and AT III levels measured in 20 uremic patients on maintenance hemodialysis immediately before and after dialysis treatment. These values were compared with those obtained from 20 matched healthy controls. Functional activities of PC was determined by coagulometric method and functional activities of AT III was determined by amidolytic method. Both the functional activities of PC and AT III in uremic patients were significantly lower than those of controls. No significant change in the level of AT III was observed with dialysis, but a progressive increase of functional activity of PC was documented with hemodialysis. On the luisis of this study, the risk of thrombosis may increase due the decrease in AT III levels. However, this effect may be compensated by the increase in PC activity, possibly due to the removal of an inhibitory substance on PC activity

Protein C, protein S and antithrombin III in children with complicated congenital heart diseases

This study was carried out on 40 patients with congenital heart disease [CHD] aged three months to seven years and divided into two groups: The first included 28 patients with complicated CHD and the second group included 12 patients with uncomplicated CHD. Ten healthy children were chosen as controls. A coagulation profile consisting of protein C, protein S, antithrombin III, factor V and factor VIII were evaluated in all patients and controls. The mean values of protein C, protein S, antithrombin III, factor V and factor VIII were significantly decreased in patients with complicated CHD compared with both uncomplicated cases and controls. Eighteen out of twenty-two patients with complicated CHD had low protein C levels [2 standard deviations below the normal mean value of the controls]. Of these children, three developed thrombotic complications and eight had evidences suggestive of consumption coagulopathy [decreased factors V and VIII]. It was concluded that decreased levels of coagulation inhibitors protein C, protein S and antithrombin III were observed in ill children with complicated CHD. With reduced levels of protein C, children with complicated CHD might have a tendency toward thrombotic complications

Thrombin antithrombin III [TAT] in patients with acute myocardial infarction

This study was conducted on 20 patients with acute myocardial infarction [AMI] and 20 healthy persons, as a control group, they were clinically free from any systemic disease. It was found that the mean TAT level was highly significantly increased in patients with AMI when compared to healthy persons and can be used as an additional criteria for diagnosis of AMI. There was a positive correlation between the mean level of TAT and the extent of infarction. After administration of thrombolytic therapy there was another elevation in the mean TAT level which may indicate reperfusion of the infarct area. Also, after administration of heparin, here was another elevation which may be due to the fact that heparin accelerate the reaction between thrombin and antithrombin III

Levels of natural anticoagulants, antithrombin III and protein C in diabetic vascular disease

Accelerated micro and macro vascular thrombotic disease is characteristic of diabetes mellitus. A hypercoagulable state is appreciated in this disease. We studied levels of natural anticoagulants such as Antithrombin III[AT III] and protein C which are factors to counteract the effects of hypercoagulable state. Both AT III and protein C levels were found decreased in diabetics with macrovascular disease suggesting that natural mechanism of anticlot formation are also affected in these patients, thus may be contributing to the thrombotic complications