Quantitative evaluation of plasma after methylene blue and white light treatment in four Chinese blood centers.

BACKGROUND: Pathogen reduction technology is an important process in the blood safety system, including solvent/detergent treatment, filtration and methylene blue-photochemical technology (MB-PCT). To investigate the quality of MB-PCT-treated plasma, plasma samples from four Chinese blood centers were analyzed over 12 months of storage to determine the recovery of activities and levels of various plasma proteins. MATERIALS AND METHODS: Ten plasma units each from the Suzhou, Yancheng, Chongqing and Shandong blood centers were divided into two aliquots. One was subjected to treatment with one of two methylene blue-photochemical technology instruments and the other was used as control. The treated and untreated sample pairs were stored at -30°C. The recovery rates of coagulation factors, inhibitor proteins, total protein, immunoglobulins, and complement proteins were measured at different time points after storage. RESULTS: The mean recovery of most proteins exceeded 80% after MB treatment. The exceptions were factor XI and fibrinogen, of which only 71.3-74% and 69.0-92.3% were retained during storage. The two equipment types differed in terms of residual MB concentration in the plasma samples (0.18 µM and 0.29 µM, respectively). They had similar protein recovery rates at 0.5 month but differed at later time points. The four blood centers differed significantly with regard to factor II, V, VIII and fibrinogen activities. Only the samples from the Shandong blood center met the methylene blue treated fresh frozen plasma requirement. The major factor that influenced the quality of the MB-FFP samples was the time taken between blood collection and storage. DISCUSSION: Methylene blue treated plasma showed reduced coagulation factor (CF) activity and protein levels. The MB treatment-induced damage to the proteins was acceptable at the four Chinese blood centers, but the quality of the MB-treated plasma in general was not satisfactory. The main factor affecting plasma quality may be the duration of the collection and processing.

Isolation and purification of human plasma coagulation Factor Ⅺ / 中国输血杂志

Objective To concentrate coagulation Factor Ⅺ(FⅪ)from human plasma.Methods FⅪwas isolated and purified from human plasma via two-step chromatography,including CM-Sepharose fast flow ion exchange and Heparin CL-6B affinity chromatography.Results The recovery rate of FⅪ was(21.02?5.04)%,the specific clotting activity of purified FⅪ was(17.59?1.96) U/mg,and the purification factor was(1162.29?129.64) fold(n=7).Conclusion The two-step chromatography is effective in concentrating FⅨ.

Isolation and purification of human coagulation factor Ⅶ from Cohn fraction Ⅲ paste / 中国输血杂志

Objective To isolate and purify human coagulation factor Ⅶ from Cohn fraction Ⅲ precipitate.Methods The purification procedure of human factor Ⅶ from Cohn fraction Ⅲ precipitate involves dissolving fraction Ⅲ,absorbing factor Ⅶ onto barium citrate and eluting,ammonium sulfate fractionation and DEAE-Sepharose Fast Flow ion exchange chromatography,and Sephadex G-100 gel filtration chromatography.Results 10.1mg purified FⅦ was obtained from 400g Cohn fraction Ⅲ precipitate.The purified FⅦ has a specific clotting activity of 1775.8U/mg and the overall yield of FⅦ specific clotting activity is 17.6% of the starting material.The purity of FⅦ was judged by SDS-PAGE and there was only one protein band on the gel.Conclusion The procedure of purifying Ⅶ from Cohn fraction Ⅲprecipitate is established with satisfactory purity.

Preparation of Protein C Deficient Plasma / 中国输血杂志

A specific monoclonal antibody(McAb),which could identfy different conformations of protein C(PC) in the presence or absence of Ca24+ .was selected and coupled with Sepharose-4B gel to form an affinity chromatographic column. When fresh plasma passed through this column.its PC would he adsorbed exclusively,and the obtained effuent was PC-deficient plasma (PCDP). The residual PC in the PCDP gained was