A Study Of Monocyte Activation And Some Haemostatic Parameters In Cases Of B-Thalassaemia

A Study Of Monocyte Activation And Some Haemostatic Parameters In Cases Of B-ThalassaemiaAbstractIntroduction:- Activated monocytes, ECs and platelets; all have roles in the pathogenesis of the hypercoagulable states that may occur in thalassaemic patients. Haemostatic disorders have been observed in -thalassaemia. Clinical symptoms related to the occurrence of thrombosis especially in the lungs, after splenectomy have been observed, although infrequent. The presence of persistent hypercoagulable state combined with the infrequent occurrence of significant thrombotic events suggest that thrombosis is largely a sub-clinical process in thalassaemia and has been associated with autopathy findings of platelet and fibrin thrombi in the microvasculature in the lungs and brain and these thrombi could contribute to PHT, low lung capacity, hypoxemia and diffusion defects associated with right heart failure (cor-pulmonale) and to the frequency of ischemic brain lesions associated with asymptomatic brain damage as detected by MRI. Thalassaemic RBCs and haemosiderosis were demonstrated to facilitate thrombin formation due to altered asymmetry of the membrane phospholipids with enhanced exposure of Ps. These factors may contribute to the activation of the coagulation process and the activation of the other blood cells including platelets, monocytes, and granulocytes, alone or together, and may induce the activation of the vascular endothelium, which further contributes to the thrombotic process.Objective: We studied the role of monocyte activation, EC activation or injury and platelet activation in the pathogenesis of the hypercoagulable state in -thalassaemia (TM and TI).Subjects and Methods: CD14 was used as a monocyte marker and CD11b as a monocytic activation marker and were studied by flow cytometry. vWF Antigen % in plasma by ELISA was used for EC activation and platelet aggregate ratio (PAR) was done for platelet activation. These tests were one for 50 thalassaemic patients divided into 3 groups and for 20 normal controls.Results: There were increased procoagulant activities of monocytes and Ecs and to lesser extent of platelets in our study. This is indicated by the increased % of activated monocytes, increased % of vWF Ag and so EC activation and decreased PAR .Conclusion: Thrombosis is largely a subclinical process in thalassaemia suggested by the presence of a persistent hypercoagulable state combined with the infrequent occurrence of significant thrombotic events. Markers of Monocyte, platelets and EC activation may be used for follow up of the thalassaemia patiants.