Thesis (Ph.D.) - Cork Institute of Technology, 2016.

Includes bibliographical references.

"Background and objectives:- The effects of anti-coagulated extracorporeal circulation on plasma levels of haemostatic proteins in plateletpheresis donors, using whole blood donors as a control group was investigated. Also, a prospective analysis of iron status in plateletpheresis donors, using whole blood donors as a control group, was investigated to assess the haematinic effects of regular anti-coagulated extracorporeal circulation and platelet collection. Materials and methods:- Blood samples from 31 regular male plateletpheresis donors and from 14 first time male whole blood donors were taken immediately before and after donation and also immediately prior to the next donation. These samples were tested for protein C activity, free protein S., fibrinogen, vWF Ag, sP-selection, sE-selection, ADAMTS-13 activity and ferritin. An additional 33 regular male plateletpheresis donors and 17 first time male whole blood donors had serum ferritin levels checked predonation. Results:- The two groups of donors in this study did not differ at baseline (p>0.05) for measurement of APTT, fibrinogen, protein C activity, free protein S, vWF Ag, sP-selection, ADAMTS-13 activity, haemoglobin level and age. There were statistically significant differences between groups for baselines values of PT (p=0.038), and sE-selection (p=0.018). All values were within the normal ranges: no significant changes were observed in these parameters across the donation process and at follow up. The vWF antigen levels pre and post plateletpheresis had overlapping 95% confidence intervals (although significant for the difference in observed values at p=0.014) and were not considered further. The observed difference in sP selection values in the whole blood donor group from pre (and immediately post) donation to the follow up sample three months later was of a different order, with a p value for the difference observed of 0.007, making it very unlikely that this was a chance finding. Plateletpheresis donors had significantly lower protein C activity levels before donation than immediately following donation (p<0.001); post-donation protein C activity was also higher than the subsequent follow-up value in these donors (p=0.007). In contrast, in whole blood donors, protein C activity before donation was higher than the value immediately following donation (p=0.001). All levels were within the physiological range. sP selection was significantly lower at 3 months follow up in the whole blood donor group (p=0.001) but did not differ in the pre and post donation samples in either group. Plateletpheresis donors had a statistically significant fall in serum ferritin after donation (p=0.005)*. In addition, platelet donors had significantly lower serum ferritin levels than first time blood donors: ferritin <20 æg L¹ was found in 6/64 (9%) of regular platelet donors and 1/31 (3%) of first time blood donors (p<0.001)*. Discussion:- The changes in protein C activity levels suggest that protein C activity is a sensitive marker of vascular endothelial stress: decreased protein C activity levels in whole blood donors following donation and increased levels in plateletpheresis donors following donation indicate that whole blood and platelet donation affect coagulation dynamics in vivo. This study supports the value of serum ferritin measurement in apheresis donor management". - (Author's abstract)