Plasma Bags Research Articles

ポータブル型急速血しょう凍結装置Ｉｎｓｔａ Ｃｏｏｌ ＭＰＩＩＩの検討

A new freezing system for preparing high quality source plasma was investigated. The MPIII™ portable freezing system consists of a freezer called the “Cell Unit” and a storage case. The MPIII cell unit and the MPIIIs cell unit, about half the size of the MPIII, were transferred to storage cases after “recharging” (storage at -40°C) and their ability to freeze apheresis plasma bags was tested. The MPIII and the MPIIIs freezers could freeze 8 and 4 plasma bags respectively to a temperature below -20°C. However, the MPIII could freeze 16 bags and the MPIIIs 9 bags, before the cell unit temperature rose up to -20°C. They could freeze and store plasma bags below -20°C for about one day when there were 12 bags in the MPIII or 6 bags in the MPIIIs.The recovery of factor VIII activity (FVIII: C) of the plasma frozen in the MPIIIs was high (97%) and was similar to that of plasma frozen in a blast freezer. This high FVIII: C did not decrease even after overnight storage in the MPIIIs.In addition, the MPIII™ portable freezing system has several other merits. No electricity is required after “recharging” the cell unit, it is safe because neither liquid nitrogen nor ethanol is required and the plasma bags are flat after freezing, which allows easy bar code reading and safe, efficient storage and transportation.Thus it is possible for the MPIII and MPIIIs systems to freeze the collected plasma at blood collection sites and to retain high FVIII: C.

Photoinactivation of Viruses in Human Fresh Plasma by Phenothiazine Dyes in Combination with Visible Light

We developed a photodynamic method to inactivate viruses in human fresh plasma. Single plasma bags were illuminated with visible light in the presence of low doses of phenothiazine dyes like methylene blue or toluidine blue. By this treatment the infectivity of different enveloped viruses including the causative agent of AIDS, HIV-1, was completely removable from the plasma. Non enveloped viruses, however, proved to be more stable. The activities of clotting factors and other plasma proteins were only slightly decreased. There was no indication that the procedure led to important structural modifications of plasma proteins. The dyes are photodynamically active at concentrations much lower than those at which they are therapeutically used as antidots in the treatment of methemoglobinemia.

Fibrin generation during production of freeze dried antihaemophilic cryoprecipitate

Thrombin activity during separation and cryoprecipitation of CPD-blood was monitored by fibrinopeptide A (FPA) determinations. After pooling and lyophilization of cryoprecipitate, the total amount of contaminating fibrin was estimated by N-terminal amino acid analyses. In addition, retention of fibrin in standard transfusion filters (170 μm) was examined by gamma counting of 125I des-AA fibrin monomer enriched cryoprecipitate prior and subsequent to filtration. Prior to pooling of cryoprecipitate, thrombin activity, as estimated by FPA levels, was most pronounced during collection of blood from the blood donors and during cryoprecipitation and thawing of the plasma bags. Comparison of these FPA concentrations to the total amount of fibrin in pooled, freeze dried cryoprecipitate, as estimated by N-terminal analyses, revealed a considerable generation of fibrin during the process of lyophilization. In freeze dried cryoprecipitate, 5.3 per cent (range 3.0–7.5 per cent) of the fibrinogen had been converted to fibrin, implying a fibrin content of 20.3–60.3 mg per bottle of 500 U factor VIII. The amount of fibrin in two bottles of a commercially available factor VIII concentrate, also containing 500 U of factor VIII, was 1115.1 and 19.8 mg, respectively. Sham transfusions of 125I des-AA fibrin monomer enriched cryoprecipitate revealed that only 1.0 per cent (range 0–2.5 per cent) of the fibrin was retained in the standard'transfusion filters. Thus, substantial amounts of fibrin may be transfused to patients upon treatment with freeze dried cryoprecipitate.

Preparation of stable lyophilized cryoprecipitate in the original frozen plasma bags.

A procedure for preparing single units of freeze-dried cryoprecipitate (cryo) in the original bags is described in detail. Batches of frozen plasma bags were rapidly thawed by rocking in a water bath, centrifuged and after complete removal of supernate the compact cryo pellets (2-5 g) were lyophilized with the aid of a holding tray with a filtered air chamber designed for this purpose. Adding synthetic amino acids has greatly improved stability of the dried concentrate during storage and has increased its resistance to heat denaturation (e.g. less than 10% loss of potency after 20 h at 70 degrees C). The method is presented as a viable option for safe and economical manufacture of a stable factor VIII concentrate.