الفهرس 
TYPES OF PLASMAOnly 14 pages are availabe for public view
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Abstract
F
FP is indicated for use in patients who are bleeding or having an invasive procedure and who are deficient in multiple coagulation factors or a single factor for which there is no factor concentrate available. It is also indicated for replacement of clotting factors during massive transfusion, for reversal of warfarin (if immediate reversal is necessary), and as the replacement fluid for plasma exchange procedures in patients with TTP. It should not be used as a volume expander, because alternative products with lower risk of infectious diseases and allergic reactions are available for this purpose (e.g., crystalloid, albumin, starch).
Although FFP is considered as an infrequent cause of major adverse reactions, the complexity of plasma proteins, the heterogeneity of its immunoglobulin content, and factors related to its processing and storage have the potential to cause a wide range of reactions with various pathophysiologic mechanisms.
The risk of any plasma product causing an adverse event or reaction depends on the source of the plasma (donor-related factors), what testing is performed, and any treatment or modification to which it has been subjected. In addition, interaction between donor factors and the patient’s immune system can lead to unwanted effects, e.g. TRALI and the development of antibodies to factor VIII.
To reduce the risk of this complication, plasma products can be prepared, including plasma frozen within 24 hrs of phlebotomy (PF24). As the name suggests, PF24 is frozen 8 to 24 h after collection and it is particularly useful for blood centers that rely on mobile collections or those that procure their source material from remote locations. Use of PF24 maximizes plasma that can be prepared from male donors that decrease the risk of TRALI.
FV and FVIII are relatively labile coagulation factors and therefore those most likely to be influenced by changes in the temperature and length of time taken to produce FFP. There have been reports showing little difference in the levels of labile coagulation factors (FV and FVIII) between FFP and PF24.
This work was conducted to assess whether therapeutically adequate levels of labile coagulation factors FV and FVIII are maintained in plasma frozen at 24 hrs as compared to fresh frozen plasma during 5-days of storage.
Twenty units of whole blood were collected in triple bags. They were kept at room temperature for 5 to 7 h before plasma separation. The separated plasma was then divided into the two satellite bags. One was immediately frozen at -20°C and labeled FFP, the other was placed in a controlled 22°C environment overnight, then frozen at-20°C. The time elapsed between blood collection and storage of this latter plasma did not exceed 24 hrs (between 20-24 hrs) and this plasma was labeled PF24. Plasma was kept frozen at -20°C for 1 month then thawed and aliquots taken after complete thawing (day 0) and at days 1, 3 and 5. The aliquots were immediately frozen till the assay time when they were thawed and assayed within one hour.
For each aliquot, Factors V and VIII were assayed by using factor-deficient commercial plasmas (Dade Behring, Marburg, Germany) and an automated coagulation analyzer (Sysmex CA 1500).
The mean FVIII activity in FFP estimated at days 0, 1, 3, 5 were 103.6 ± 18.1 U/dL, 79.0 ± 8.3 U/dL, 67.5 ± 6.2 U/dL, 62.6 ± 6.9 U/dL respectively, however its levels in PF24 at days 0, 1, 3, 5 were 82.5 ± 11.2 U/dL, 69.7 ± 7.7 U/dL, 65.2 ± 6.3 U/dL, 55.5 ± 7.4 U/dL respectively.
On comparing the mean values of FVIII activity in FFP and PF24 at corresponding days (after thawing and along storage period) the values were lower in FP24 and the difference was significant at all days (p<0.001) except for day 3 where the decrease was not statistically significant (p>0.05).
Comparison of mean FVIII activity in FFP along the storage days versus each other revealed a highly significant decrease in the activity with storage (p <0.001). The same observation was true for PF24.
The mean FV activity in FFP estimated at days 0, 1, 3, 5 were 97.3±12.8U/dL, 86.3±11.5 U/dL, 72.5±9.1 U/dL, 61.7±8.4U/dL respectively, its levels in PF24 at days 0, 1, 3, 5 were 90.5±10.8U/dL, 81.8±11.0U/dL, 68.7±10.3U/dL, 56±10.4U/dL respectively.
Comparison of FV activity after thawing and during storage period in FFP and PF24 revealed that the values for PF24 were lower than the corresponding values for FFP. However, the difference was not significant at day 0 as well as along the whole storage period (p>0.05).
Comparison of mean levels of FV activity in different days of storage versus each other revealed a highly significant decrease in the activity along storage period (p <0.001) both in FFP and PF24.
As well as comparing FVIII levels in PF24 and FFP, it is also important to consider the residual coagulation factor activity in the plasma that patients receive and whether it meets requirements.
from this perspective, PF24 after thawing did not comply with AABB requirement (>75% of units should have >0.80 IU/mL FVIII), yet it met UK specifications (>75% of units must contain >0.70 IU/mL FVIII) and those of the Council of Europe guidelines (>0.70 IU/mL FVIII, percentage of units not specified).
The reduction in FVIII does not reduce the quality of frozen thawed plasma because this component should not be utilized for treating hemophilia A, rather FVIII concentrates, recombined or plasma derived and rarely cryoprecipitate are the products of choice. The reduction of FVIII levels in PF24 is not clinically important for other patients. Actually, most patients requiring FFP including liver disease patients have clinically adequate or even high plasma levels of FVIII, which is an acute-phase reactant.