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Residual leucocyte in platelet concentrates accelerate the rate of platelet storage lesion
Intematiooal Forum
blood components to patients awaiting renal transplantation, with or without an initial programme of white blood cell-containing transfusions. Those interventions in the Possible category should only be done in the context of a protocol to investigate effectiveness. Not Indicated-no compelling clinical or scientific evidence to demonstrate effectiveness (in particular where alternative strategies are clearly superior at present). (4 Prevention of transfusion-related graft versus host disease. Irradiation of cellular blood components remains the standard treatment. lung injury (due to pre-formed anti(ii) Prevention of acute post-transfusion granulocyte antibodies in donor plasma). transmission of HIV, Hepatitis B or Hep(iii] Prevention of transfusion-related atitis C. of fresh frozen plasma and other plasma components, or (iv) Filtration cryoprecipitate. Iv1 To reduce HTLV transmission by cellular blood components. (vi) Transfusion of cellular blood components to patients not included in the categories mentioned above, and who are receiving a limited number of transfusions over a restricted time period [e.g. in relation to surgical procedures J. Evaluation of Benefits and Costs We therefore recommend that all the indications listed should be subject to detailed and careful costing as well as to the rigorous evaluation of benefits. We believe that the rational comparison of benefits and costs, though difficult and time-consuming, is essential if the appropriate use of technologies like leucodepletion is to be accurately defined.
RESIDUAL LEUCOCYTE IN PLATELET CONCENTRATES ACCELERATE THE RATE OF PLATELET STORAGE LESION M. I: Segfiatclhn and H. Bessos North London Blood Transfusion Centre, Colindale Avenue, London, U.K. Leucocytes in platelet concentrates (PC) release proteases such as elastase, cathepsin and other chymotrypsin like enzymes which degrade platelet glycoproteins GpIb/IX & GpIIb/IIIa complexes, as well as, platelet von Willebrand factor (vWF). Therefore leucocytes accelerate the rate of platelet storage lesion. We have used four markers (dMPV, glycocalicin, microvesicule bound Gp IIbAIIa and vWP in platelet supematant) which describe integrity of platelets in vitro, to assess the extend of platelet storage lesion in the presence of leucocytes. In a preliminary study, pooled platelet concentrates, containing 3.0-3.5 x 10” platelets in 300 mL of plasma, in extended shelf life packs (PL 732), leucocytes in the range of 0.25-0.39 x 10Y/pack appear to shorten the shelf life as estimated by changes in dMPV, which rapidly fell to zero value at day 3-4. The glycocalicin levels (GC, a major segment of GpIb) were substantially higher (40.5 + 32.2 vs 7.8 + 4.0 CLg/mL) on those PC with negligible dMPV value, at the end of shelf life. We found higher GC levels in units containing leucocytes higher than 0.39 x 10Y/pack and there was a significant inverse n 1511-E
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62 Transf~.~s. Sci. Vol. 15,No. 1
correlation between dMPV and both microvesicule bound (I = -0.73) and soluble GC (I = -0.63) released from platelets during storage. A lo-fold increase in the level of GpIIb/IIIa also occurred in a unit of PC in which platelet underwent irreversible dMPV and pH fell below 6.2. In a parallel study on standard PC a significant correlation was found between GC levels and vWP:Ag (r = 0.54, X0.01), indicating a concurrent release of vWP:Ag and GC due to platelet damage. These findings suggest that the removal of leucocytes from PC will improve the functional integrity of stored platelets.
THE USE OF LEUCODEPLETING FILTERS DURING PLATELETPHERESIS WITH AN ASSESSMENT OF POST-FILTRATION IN VITRO PLATELET FUNCTION J. F. Harrison, I. Ma&e, S. Machin, T. McCarthy North East Thames Regional Transfusion Centre, Brentwood, Essex Using a specially designed harness, platelet-rich plasma (PRP) was collected using the Haemonetics PCS and filtered to effect leucodepletion during the collection process. 60 procedures were performed during each of which approximately 200 mL PRP was collected and then allowed to pass by gravity through either a Pall PLSO or PLlOO filter or a Sepacell 10A filter, whilst the PRP collection process was still continuing. The PL50 filter was used during 5 procedures, the PLlOO for 30 and the Sepacell 10A for 25 procedures. The mean post-filtration white blood cell (WBC) contamination using PL50 was 108.4 x 106/L, which was unacceptably high. Using PLlOO filters, mean post filtration WBC was 1.6 x 106/L and for Sepacell 10A the mean post-filtration WBC was 0.9 x 106/L. Both filters provided satisfactory white blood cell removal. Mean platelet loss during filtration for PLlOO was 7.6% and for Sepacell 10A 4.5%. Platelet aggregation tests, nucleotides and (3-thromboglobulin were performed on PRP samples for 20 procedures where the Pall PLlOO filter was used and 20 procedures where the Sepacell 10A was used. The platelet function tests were performed on unfiltered PRP and post-filtration samples immediately and l-3 days after storage of the platelets at room temperature with agitation. The results showed no significant changes in in vitro platelet function when unfiltered PRP and PRP filtered during the collection procedure were compared. The results of leucodepletion during PRP collection with the Haemonetits PCS machine were excellent using both the PLlOO and Sepacell 10A leucodepleting filters and filtering at the time of PRP collection did not adversely affect in vitro platelet function.
blood components to patients awaiting renal transplantation, with or without an initial programme of white blood cell-containing transfusions. Those interventions in the Possible category should only be done in the context of a protocol to investigate effectiveness. Not Indicated-no compelling clinical or scientific evidence to demonstrate effectiveness (in particular where alternative strategies are clearly superior at present). (4 Prevention of transfusion-related graft versus host disease. Irradiation of cellular blood components remains the standard treatment. lung injury (due to pre-formed anti(ii) Prevention of acute post-transfusion granulocyte antibodies in donor plasma). transmission of HIV, Hepatitis B or Hep(iii] Prevention of transfusion-related atitis C. of fresh frozen plasma and other plasma components, or (iv) Filtration cryoprecipitate. Iv1 To reduce HTLV transmission by cellular blood components. (vi) Transfusion of cellular blood components to patients not included in the categories mentioned above, and who are receiving a limited number of transfusions over a restricted time period [e.g. in relation to surgical procedures J. Evaluation of Benefits and Costs We therefore recommend that all the indications listed should be subject to detailed and careful costing as well as to the rigorous evaluation of benefits. We believe that the rational comparison of benefits and costs, though difficult and time-consuming, is essential if the appropriate use of technologies like leucodepletion is to be accurately defined.
RESIDUAL LEUCOCYTE IN PLATELET CONCENTRATES ACCELERATE THE RATE OF PLATELET STORAGE LESION M. I: Segfiatclhn and H. Bessos North London Blood Transfusion Centre, Colindale Avenue, London, U.K. Leucocytes in platelet concentrates (PC) release proteases such as elastase, cathepsin and other chymotrypsin like enzymes which degrade platelet glycoproteins GpIb/IX & GpIIb/IIIa complexes, as well as, platelet von Willebrand factor (vWF). Therefore leucocytes accelerate the rate of platelet storage lesion. We have used four markers (dMPV, glycocalicin, microvesicule bound Gp IIbAIIa and vWP in platelet supematant) which describe integrity of platelets in vitro, to assess the extend of platelet storage lesion in the presence of leucocytes. In a preliminary study, pooled platelet concentrates, containing 3.0-3.5 x 10” platelets in 300 mL of plasma, in extended shelf life packs (PL 732), leucocytes in the range of 0.25-0.39 x 10Y/pack appear to shorten the shelf life as estimated by changes in dMPV, which rapidly fell to zero value at day 3-4. The glycocalicin levels (GC, a major segment of GpIb) were substantially higher (40.5 + 32.2 vs 7.8 + 4.0 CLg/mL) on those PC with negligible dMPV value, at the end of shelf life. We found higher GC levels in units containing leucocytes higher than 0.39 x 10Y/pack and there was a significant inverse n 1511-E
61
62 Transf~.~s. Sci. Vol. 15,No. 1
correlation between dMPV and both microvesicule bound (I = -0.73) and soluble GC (I = -0.63) released from platelets during storage. A lo-fold increase in the level of GpIIb/IIIa also occurred in a unit of PC in which platelet underwent irreversible dMPV and pH fell below 6.2. In a parallel study on standard PC a significant correlation was found between GC levels and vWP:Ag (r = 0.54, X0.01), indicating a concurrent release of vWP:Ag and GC due to platelet damage. These findings suggest that the removal of leucocytes from PC will improve the functional integrity of stored platelets.
THE USE OF LEUCODEPLETING FILTERS DURING PLATELETPHERESIS WITH AN ASSESSMENT OF POST-FILTRATION IN VITRO PLATELET FUNCTION J. F. Harrison, I. Ma&e, S. Machin, T. McCarthy North East Thames Regional Transfusion Centre, Brentwood, Essex Using a specially designed harness, platelet-rich plasma (PRP) was collected using the Haemonetics PCS and filtered to effect leucodepletion during the collection process. 60 procedures were performed during each of which approximately 200 mL PRP was collected and then allowed to pass by gravity through either a Pall PLSO or PLlOO filter or a Sepacell 10A filter, whilst the PRP collection process was still continuing. The PL50 filter was used during 5 procedures, the PLlOO for 30 and the Sepacell 10A for 25 procedures. The mean post-filtration white blood cell (WBC) contamination using PL50 was 108.4 x 106/L, which was unacceptably high. Using PLlOO filters, mean post filtration WBC was 1.6 x 106/L and for Sepacell 10A the mean post-filtration WBC was 0.9 x 106/L. Both filters provided satisfactory white blood cell removal. Mean platelet loss during filtration for PLlOO was 7.6% and for Sepacell 10A 4.5%. Platelet aggregation tests, nucleotides and (3-thromboglobulin were performed on PRP samples for 20 procedures where the Pall PLlOO filter was used and 20 procedures where the Sepacell 10A was used. The platelet function tests were performed on unfiltered PRP and post-filtration samples immediately and l-3 days after storage of the platelets at room temperature with agitation. The results showed no significant changes in in vitro platelet function when unfiltered PRP and PRP filtered during the collection procedure were compared. The results of leucodepletion during PRP collection with the Haemonetits PCS machine were excellent using both the PLlOO and Sepacell 10A leucodepleting filters and filtering at the time of PRP collection did not adversely affect in vitro platelet function.