四种病毒灭活方法用于登革病毒灭活效果的比较

目的评价常用病毒灭活方法对血液制品中登革病毒(DENV)的灭活效果。方法将单采新鲜冰冻血浆(FFP),人凝血因子Ⅷ(FⅧ)和静脉注射免疫球蛋白(IVIG)3种血浆及其制品中加入高滴度(8.00-9.25)的登革病毒液,分别采用亚甲蓝(MB)光化学法灭活FFP、有机溶剂/去污剂(S/D)法灭活FⅧ、低pH常温孵化法和巴氏消毒法灭活IVIG;以1×10~6/mL A549细胞接种于T25的培养瓶中作为病毒传代及滴度滴定指示细胞,将灭活前后的血浆及制品接种于A549细胞并检测其DENV滴度,并通过qRT-PCR对DENV RNA做定量检测;评估不同的灭活方法对DENV的灭活效果。结果 DENV滴度下降:MB光化学法灭活FFP下降滴度≥5.92 log,S/D法灭活FⅧ下降滴度≥5.17 log、巴氏法和低pH法灭活IVIG均下降滴度≥5.92 log,其中MB光化学法灭活FFP、SD灭活FⅧ及巴氏法灭活IVIG后DENV RNA(cp/mL)降低1.25 log-2.25 log,低pH法灭活IVIG后DENV RNA(cp/mL)降低0.17 log。所有血浆和血液制品样品经灭活后,在DENV宿主细胞上3代盲传后均未检测到DENV RNA。结论 4种常用病毒灭活方法均能有效灭活血浆及血液制品中的DENV。     

Two pathogen reduction technologies—methylene blue plus light and shortwave ultraviolet light—effectively inactivate hepatitis C virus in blood products

BACKGROUND: Contamination of blood products with hepatitis C virus (HCV) can cause infections resulting in acute and chronic liver diseases. Pathogen reduction methods such as photodynamic treatment with methylene blue (MB) plus visible light as well as irradiation with shortwave ultraviolet (UVC) light were developed to inactivate viruses and other pathogens in plasma and platelet concentrates (PCs), respectively. So far, their inactivation capacities for HCV have only been tested in inactivation studies using model viruses for HCV. Recently, a HCV infection system for the propagation of infectious HCV in cell culture was developed. STUDY DESIGN AND METHODS: Inactivation studies were performed with cell culture–derived HCV and bovine viral diarrhea virus (BVDV), a model for HCV. Plasma units or PCs were spiked with high titers of cell culture–grown viruses. After treatment of the blood units with MB plus light (Theraflex MB‐Plasma system, MacoPharma) or UVC (Theraflex UV‐Platelets system, MacoPharma), residual viral infectivity was assessed using sensitive cell culture systems. RESULTS: HCV was sensitive to inactivation by both pathogen reduction procedures. HCV in plasma was efficiently inactivated by MB plus light below the detection limit already by 1/12 of the full light dose. HCV in PCs was inactivated by UVC irradiation with a reduction factor of more than 5 log. BVDV was less sensitive to the two pathogen reduction methods. CONCLUSIONS: Functional assays with human HCV offer an efficient tool to directly assess the inactivation capacity of pathogen reduction procedures. Pathogen reduction technologies such as MB plus light treatment and UVC irradiation have the potential to significantly reduce transfusion‐transmitted HCV infections.     

Plasma transfusion in liver transplantation: a randomized,double‐blind,multicenter clinical comparison of three virally secured plasmas

BACKGROUND: The clinical equivalence of plasma treated to reduce pathogen transmission and untreated plasma has not been extensively studied. A clinical trial was conducted in liver transplant recipients to compare the efficacy of three plasmas. STUDY DESIGN AND METHODS: A randomized, equivalence, blinded trial was performed in four French liver transplantation centers. The three studied (fresh‐frozen) plasmas were quarantine (Q‐FFP), methylene blue (MB‐FFP), and solvent/detergent (S/D‐FFP) plasmas. The primary outcome was the volume of plasma transfused during transplantation. Secondary outcomes included intraoperative blood loss, hemostasis variables corrections, and adverse events. RESULTS: One‐hundred patients were randomly assigned in the MB‐FFP, 96 in the S/D‐FFP, and 97 in the Q‐FFP groups, respectively. The median volumes of plasma transfused were 2254, 1905, and 1798 mL with MB‐FFP, S/D‐FFP, and Q‐FFP, respectively. The three plasmas were not equivalent. MB‐FFP was not equivalent to the two other plasmas, but S/D‐FFP and Q‐FFP were equivalent. The median numbers of transfused plasma units were 10, 10, and 8 units with MB‐FFP, S/D‐FFP, and Q‐FFP, respectively. Adjustment on bleeding risk factors diminished the difference between groups: the excess plasma volume transfused with MB‐FFP compared to Q‐FFP was reduced from 24% to 14%. Blood loss and coagulation factors corrections were not significantly different between the three arms. CONCLUSION: Compared to both Q‐FFP and S/D‐FFP, use of MB‐FFP was associated with a moderate increase in volume transfused, partly explained by a difference in unit volume and bleeding risk factors. Q‐FFP was associated with fewer units transfused than either S/D‐FFP or MB‐FFP.     

Inactivation of parvovirus B19 in human platelet concentrates by treatment with amotosalen and ultraviolet A illumination

BACKGROUND: The human erythrovirus B19 (B19) is a small (18- to 26-nm) nonenveloped virus with a single-stranded DNA genome of 5.6 kb. B19 is clinically significant and is also generally resistant to pathogen inactivation methods. Photochemical treatment (PCT) with amotosalen and ultraviolet A (UVA) inactivates viruses, bacteria, and protozoa in platelets (PLTs) and plasma prepared for transfusion. In this study, the capacity of PCT to inactivate B19 in human PLT concentrates was evaluated. STUDY DESIGN AND METHODS: B19 inactivation was measured by a novel enzyme-linked immunosorbent spot (ELISPOT) erythroid progenitor cell infectivity assay and by inhibition of long-range (up to 4.3 kb) polymerase chain reaction (PCR), under conditions where the whole coding region of the viral genome was amplified. B19-infected plasma was used to test whether incubation of amotosalen with virus before PCT enhanced inactivation compared to immediate PCT. RESULTS: Inactivation of up to 5.8 log of B19 as measured by the infectivity assay, or up to 6 logs as measured by PCR inhibition can be achieved under non-limiting conditions. Inactivation efficacy was found to increase with incubation prior to UVA illumination. Without incubation prior to illumination 2.1 +0.4 log was inactivated as determined by infectivity assay. When measured by PCR inhibition, inactivation varied inversely with amplicon size. When primers that spanned the entire coding region of the B19 genome were used, maximum inhibition of PCR amplification was demonstrated. CONCLUSION: Under defined conditions, PCT with amotosalen combined with UVA light can be used to inactivate B19, a clinically significant virus that can be transmitted through blood transfusion, and heretofore has been demonstrated to be refractory to inactivation.     

Storage of thawed plasma for a liquid plasma bank: impact of temperature and methylene blue pathogen inactivation

BACKGROUND: Rapid transfusion of fresh‐frozen plasma (FFP) is desired for treating coagulopathies, but thawing and issuing of FFP takes more than 40 minutes. Liquid storage of plasma is a potential solution but uncertainties exist regarding clotting factor stability. We assessed different storage conditions of thawed FFP and plasma treated by methylene blue plus light (MB/light) for pathogen inactivation. STUDY DESIGN AND METHODS: Fifty thawed apheresis plasma samples (approx. 750 mL) were divided into three subunits and either stored for 7 days at 4°C, at room temperature (RT), and at 4°C after MB/light treatment. Clotting factor activities (Factor [F] II, FV, FVII through FXIII, fibrinogen, antithrombin, von Willebrand factor antigen, Protein C and S) were assessed after thawing and on Days 3, 5, and 7. Changes were classified as “minor” (activities within the reference range) and “major” (activities outside the reference range). RESULTS: FFP storage at 4°C revealed major changes for FVIII (median [range], 56% [33%‐114%]) and Protein S (51% [20%‐88%]). Changes were more pronounced when plasma was stored at RT (FVIII, 59% [37%‐123%]; FVII, 69% [42%‐125%]; Protein S, 20% [10%‐35%]). MB/light treatment of thawed FFP resulted in minor changes. However, further storage for 7 days at 4°C revealed major decreases for FVIII (47% [12%‐91%]) and Protein S (49% [18%‐95%]) and increases for FVII (150% [48%‐285%]) and FX (126% [62%‐206%]). CONCLUSION: Storage of liquid plasma at 4°C for 7 days is feasible for FFP as is MB/light treatment of thawed plasma. In contrast, storage of thawed plasma for 7 days at RT or after MB/light treatment at 4°C affects clotting factor stability substantially and is not recommended.     

Thrombin generation capacity is impaired in methylene-blue treated plasma compared to normal levels in single-donor fresh-frozen plasma, a licensed solvent/detergent-treated plasma (Octaplas) and a development product (Uniplas).

Impaired capacity of thrombin generation (TG) was found in single-donor fresh-frozen plasma (FFP) units subjected to medical device treatment by a combination of methylene-blue dye and subsequent white-light exposure (MB plasma, MBP) compared to normal levels in non-MB-treated single-donor FFP, the licensed plasma product Octaplas, and a product under development (Uniplas; working title) applicable independently from the recipient's blood group. This result held true for MBP units obtained from two different European sources revealing a more significant TG impairment using the local inactivation system in blood banks ("in-house") than an industrial MB treatment. Supplementation of functional fibrinogen to physiological levels did not normalise the altered TG capacity in MBP, whereas addition of Octaplas did. No clear-cut correlation between coagulation factor levels in MBP and hampered TG capacity was found, suggesting a composite effect of impairment. A thorough elucidation and evaluation regarding the possible clinical impact of these findings seems prudent.     

Coagulation factor levels in cryosupernatant prepared from plasma treated with amotosalen hydrochloride (S-59) and ultraviolet A light

BACKGROUND: The standard treatment for thrombotic thrombocytopenic purpura (TTP) is plasma exchange with fresh-frozen plasma (FFP). Exposure to large volumes of FFP increases the risk of transfusion-transmitted infections. Cryosupernatant (CSP) offers a theoretical advantage over FFP, because it lacks the large von Willebrand factor (VWF) forms implicated in the pathogenesis of TTP. This study compared the hemostatic variables of CSP prepared from FFP treated with a photochemical pathogen inactivation process to CSP prepared from conventional FFP. STUDY DESIGN AND METHODS: Forty CSP units were prepared from North American blood group A donor FFP. Twenty-one of the FFP units were individually treated with amotosalen hydrochloride (S-59) and ultraviolet A light (test, photochemically treated FFP), and 19 units were not treated (control, FFP). RESULTS: Hemostatic variables of test and control CSP were similar and within reported ranges for conventional FFP with the exception of those properties depleted in CSP. VWF-cleaving protease activity (VWF:CP) and protein S (PS) levels (total and free antigen and activity) were within the conventional FFP reference range for test and control CSP. There were statistical differences between test and control CSP for alpha(2)-antiplasmin, antithrombin, protein C, and VWF:CP on a per-volume basis, but all levels were within the reference range for FFP, and the differences were not significant when expressed per gram of CSP protein. CONCLUSION: S-59-treated CSP retained adequate levels of critical plasma proteins for plasma exchange therapy in acute TTP. The data indicate good preservation of hemostasis control proteins such as PS, alpha(2)-antiplasmin, and VWF:CP activity (ADAMTS13).     

A randomized, controlled Phase III trial of therapeutic plasma exchange with fresh-frozen plasma (FFP) prepared with amotosalen and ultraviolet A light compared to untreated FFP in thrombotic thrombocytopenic purpura

BACKGROUND: Photochemical treatment of fresh-frozen plasma (FFP) with amotosalen and ultraviolet (UV) A light (PCT FFP) results in inactivation of a broad spectrum of pathogens while retaining coagulation factor activity, antithrombotic proteins, and von Willebrand factor-cleaving protease (VWF-CP) activity. STUDY DESIGN AND METHODS: A randomized, controlled, double-blind Phase III trial was conducted with PCT FFP or control FFP for therapeutic plasma exchange (TPE) in patients with thrombotic thrombocytopenic purpura (TTP). Owing to the rarity of this diagnosis, the trial was not powered to demonstrate small differences between treatment groups. Patients were treated with study FFP for a maximum of 35 days until remission was achieved (for a maximum of 30 daily study TPEs with no remission) plus an additional 5 days after remission. RESULTS: Among the 35 patients treated, the primary endpoint, remission within 30 days, was achieved by 14 of 17 (82%) PCT patients and 16 of 18 (89%) control patients (p = 0.658) The 90 percent confidence interval for treatment difference in remission rate for test - control was (-0.291 to 0.163). Time to remission, relapse rates, time to relapse, total volume and number of FFP units exchanged, and number of study TPEs were not significantly different between groups. Improvement in VWF-CP and inhibitors was similar for both groups. The overall safety profile of PCT FFP was similar to control FFP. No antibodies to amotosalen neoantigens were detected. CONCLUSION: The comparable results between treatment groups observed from this small trial suggest that TPE with PCT FFP was safe and effective for treatment of TTP.     

Cryoprecipitate prepared from plasma treated with methylene blue plus light: increasing the fibrinogen concentration

When cryoprecipitate is prepared from plasma which has been treated with methylene blue plus light (MB) for the purpose of virus inactivation, clottable fibrinogen content is 40% lower compared with units prepared from untreated plasma. Initial studies showed that when frozen MB plasma units were removed to +2 to +6 degrees C for 4 h and then returned to -40 degrees C prior to cryoprecipitation, fibrinogen recoveries increased from 24 to 42%. Although fibrinogen yield improved when plasma units were stored at +2 to +6 degrees C for varying lengths of time, FVIII levels decreased with increasing time. Conditioning for 8 h was studied in more detail. Groups of two plasma units were mixed together, divided into two equal units, frozen/thawed and treated with MB. One of each pair was stored continually at -40 degrees C, whereas the other was removed to +2 to +6 degrees C for 8 h. Samples were assayed for fibrinogen, FVIII, VWF:Ristocetin cofactor activity (RCo), VWF:Ag and VWF:Collagen binding (CB). The cryoprecipitate fibrinogen content increased to a mean of 207 mg unit(-1). VWF:Ag, VWF:RCo and VWF:CB recoveries also increased. FVIII recovery decreased from 50 to 45% (mean 124 iu unit(-1)). Conditioning has been validated for routine production of cryoprecipitate from imported plasma.     

Changes in functional activities of plasma fibrinogen after treatment with methylene blue and red light

BACKGROUND: Methylene blue (MB) plus light treatment used for virus inactivation of human plasma units may lead to changes in the functional activities of fibrinogen. STUDY DESIGN AND METHODS: Single-donor units of fresh plasma were treated with 1.0 microM MB and a red light dose of 48 J per cm2. The effects of MB plus red light treatment on fibrinogen clottability, fibrin polymerization and gelation, clot stabilization, and fibrinolysis were studied. RESULTS: The concentration of clottable fibrinogen was unchanged during MB plus red light treatment, but a light-dose-dependent decrease of the concentration of functional fibrinogen was found. The initial release rate of fibrinopeptide A was slightly increased after MB plus red light treatment. Turbidity measurements of fibrin gel showed prolonged clotting time, lower fibrin fiber mass-to-length ratio, and slightly smaller fiber diameter. At a given clotting time, a gel with lower fibrin fiber mass-to-length ratio was produced. Clot stability and fibrinolysis remained normal. l-Histidine added to plasma before MB plus red light treatment normalized the thrombin-induced coagulation time in a dose-dependent way. CONCLUSION: MB plus red light treatment affected the polymerization and gelation phase of fibrin. A tighter fibrin gel structure was formed. No effect on stabilization of fibrin clot or fibrinolysis was found.     

The effect of methylene blue phototreatment on plasma proteins and in vitro coagulation capability of single-donor fresh-frozen plasma

BACKGROUND: Photodynamic virus inactivation of fresh-frozen plasma (FFP) may result in its impaired coagulation capability. STUDY DESIGN AND METHODS: Double-volume plasmapheresis samples from 11 donors were divided in pairs of 250 mL. One group underwent methylene blue (MB) phototreatment (MB-FFP). The other group was treated according to the standards of the American Association of Blood Banks for preparation and storage of FFP. Parameters of hemostasis and clinically important plasma proteins were tested in native plasma, thawed MB-FFP, thawed FFP, and twice-frozen and thawed FFP (FFP-II). RESULTS: Mean activities of factor V (73.4 vs. 94.5%; p < 0.01), factor VIII (58.1 vs. 86.7%; p < 0.001), and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) were reduced in MB-FFP as compared to those in FFP. The comparison of MB-FFP to FFP-II revealed reduced activities of factor VIII (58.1 vs. 85.2%; p < 0.001) and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) but no changes in factor V. Activated partial thromboplastin time in MB-FFP was prolonged beyond the upper normal range (+5.3 sec; p < 0.001) and prothrombin time increased in MB-FFP versus FFP (+0.96 sec; p < 0.001). CONCLUSION: MB phototreatment reduces the in vitro coagulation capacity of FFP, most likely as a result of the effects of an additional freezing and thawing procedure and photooxidation-induced protein damage.     

Evaluation of bacterial inactivation in prestorage pooled, leukoreduced, whole blood-derived platelet concentrates suspended in plasma prepared with photochemical treatment

BACKGROUND: Photochemical treatment (PCT) with amotosalen and ultraviolet light was developed to inactivate pathogens in platelet (PLT) components suspended in 35 percent plasma and 65 percent additive solution (AS). Because PLT additive solutions (ASs) are not used in the United States, this study evaluated the ability of the PCT process to inactivate low levels of bacteria in pooled whole blood-derived PLTs (RDP) suspended in 100 percent plasma. STUDY DESIGN AND METHODS: Four replicate experiments were performed with two Gram-positive organisms, Staphylococcus epidermidis and Staphylococcus aureus, and two Gram-negative organisms, Klebsiella pneumoniae and Escherichia coli. For each experiment, 6 ABO-identical RDP units were pooled, leukoreduced before or after pooling, inoculated to approximately 1 to 10 colony-forming units per mL with plasma-resistant bacteria, and treated with the PCT process. Residual viable bacterial levels were measured before and after each step and 4 and 6 days after inoculation. For each bacterium studied, a fifth RDP pool was prepared and contaminated, but not treated. These units served as controls for bacterial growth. RESULTS: Growth of S. epidermidis, S. aureus, and K. pneumoniae was eliminated in all four treated pools while growth continued in the control pools. There was no growth of E. coli in the treated pools and the control pool. CONCLUSION: These pilot experiments demonstrate inactivation of bacteria in PLTs suspended in plasma, suggesting that the PCT process may address contamination in conventional RDPs. Additional experiments with a wider range of bacteria and evaluation of PLT function in 100 percent plasma will be needed before implementation.     

A biochemical comparison of a pharmaceutically licensed coagulation active plasma (Octaplas) with a universally applicable development product (Uniplas) and single-donor FFPs subjected to methylene-blue dye and white-light treatment.

The strive for more standardised and highly efficacious products is one of the important mainstays in modern haemotherapy. Coagulation active plasma for transfusion is the product of choice when treating hereditary or acquired isolated or complex coagulopathies, when no specific concentrate is available. The aim of this study was to perform an extensive biochemical comparison of the pharmaceutically licensed coagulation active plasma named Octaplas with an identical, but universally applicable, development product (Uniplas, working title) and single-donor fresh-frozen plasma (FFP) units subjected to a medical device treatment using a combination of methylene-blue dye and subsequent white-light exposure (MB plasma). Our study showed that there are differences in the biochemical characteristics between Octaplas and MB plasma, while Uniplas revealed the same quality as Octaplas. The variability of selected plasma proteins in the 20 individual MB plasma units tested was high compared to Octaplas/Uniplas. Beyond the reported decreased levels of protein S and plasmin inhibitor found in Octaplas/Uniplas, and the significant loss of fully functional fibrinogen in MB plasma and its impact on selected global coagulation parameters, the latter product additionally revealed several coagulation factor activities outside the ranges given for normal single-donor FFP. It is important for plasma prescribers to be aware of the major inherent differences between Octaplas and MB plasma.     

Quantitative and qualitative analysis of coagulation factors in cryoprecipitate prepared from fresh‐frozen plasma inactivated with amotosalen and ultraviolet A light

BACKGROUND: There were no previous studies about the quality of cryoprecipitate prepared from fresh‐frozen plasma (FFP) inactivated with amotosalen and ultraviolet A (UVA) light. The aim of this study was to analyze the quantity and quality of coagulation factors in cryoprecipitate prepared from FFP treated with amotosalen and UVA light. STUDY DESIGN AND METHODS: FFP was obtained from whole blood donations and inactivated with amotosalen and UVA light according to the manufacturer's instructions. Fibrinogen, factor VIII (FVIII), von Willebrand factor antigen (VWF : Ag) and activity (VWF : RCo), the von Willebrand factor cleavage protease activity (ADAMTS‐13), and the multimeric structure of VWF were analyzed. RESULTS: The content of fibrinogen, FVIII, and ADAMTS‐13 was lower in cryoprecipitates prepared from amotosalen‐treated plasma when compared with cryoprecipitates prepared from nontreated plasma (35, 40, and 18% loss, respectively). The quantity and quality of VWF as well as VWF multimer patterns were not affected by the inactivation method. CONCLUSION: Cryoprecipitates prepared from amotosalen‐treated FFP contained significantly reduced levels of fibrinogen, FVIII, and ADAMTS‐13. However, the VWF quantity and quality was well preserved.     

Filtration of methylene blue-photooxidized plasma: influence on coagulation and cellular contamination

BACKGROUND: Virus inactivation of plasma can be achieved by photodynamic methods in the presence of phenothiazine dyes such as methylene blue (MB). Subsequent filtration may increase the efficacy of virus inactivation and reduce adverse effects of WBC contamination and MB. STUDY DESIGN AND METHODS: This study examined the effect of filtration with three different filters (MBF1, MBF2, and MBF3) on MB concentration, residual cells, coagulation factors, and activation measures of coagulation, fibrinolysis, and complement in MB-treated (1 microM/L) plasma units. RESULTS: Filtration reduced the concentration of MB by > or = 89 percent. WBCs were depleted by 92 percent (MBF1) and >99.9 percent (MBF2 and MBF3). Treatment with MB significantly decreased the coagulation potency from levels in untreated plasma, as measured by thromboplastin time ratio (112 +/- 18% vs. 95 +/- 11%), activated partial thromboplastin time (40 +/- 3 sec vs. 44 +/- 3 sec), thrombin time (16.9 +/- 1.1 sec vs. 18.6 +/- 1.5 sec), factor VIII (1.09 +/- 0.21 U/mL vs. 0.85 +/- 0.13 U/mL), and vWF (0.94 +/- 0.65 U/mL vs. 0.65 +/- 0.24 U/mL). Filtration did not further decrease these values, while factor XI (0.75 +/- 0.22 U/mL vs. 0.37 +/- 0.20 U/mL) and prekallikrein values decreased in MB plasma units filtered with the MBF3. In addition, activated factor XII (0.7 +/- 0.5 microg/L vs. 4.5 +/- 1.0 microg/L) increased. CONCLUSION: WBCs and MB can be eliminated from MB-treated plasma units by filtration. Differences in biocompatibility of the different filters, especially the influence on the contact phase of coagulation, must be taken into consideration.     

核黄素光化学法灭活单采血小板中巨细胞病毒的效果评价

目的探讨核黄素光化学法灭活单采血小板中巨细胞病毒的效果及血小板一部分生化和生理学指标的改变。方法将14ml浓度为500μmol／L核黄素加到125ml的单采血小板悬液中,再将一定滴度约6log TCID50／ml的人类巨细胞病毒标准株（HCMV AD169）分别注入上述混悬液中,经265～370nm广谱紫外光（6．2J／m1）照射8～10min后,分别加至人胚肺成纤维细胞（HELF）单层中培养,与对照细胞比较观察细胞病变情况（CPE）,测定其滴度,并观察血小板一部分体外参数的变化情况。结果经浓度50μmol／L的核黄素结合强度为6．2J／ml紫外光照射8～10min,可将滴度为6logTCID50／ml模型病毒的组织培养半数感染量（TCID50）下降至FDA规定的灭活效果标准的下限值（〈0．43logTCID50／ml）。结论核黄素结合紫外光照射可以有效灭活人类巨细胞病毒,而单采血小板的各项生化、生理学指标和阴性对照比较差异均无统计学意义。     

Main Properties of the THERAFLEX MB-Plasma System for Pathogen Reduction

Methylene blue (MB) treated plasma has been in clinical use for 18 years. The current THERAFLEX MB-Plasma has a number of improved features compared with the original Springe methodology. This overview embodies: the biochemical characteristics of MB, the mechanism of the technology, toxicology, pathogen reduction capacity, current position in clinical setting and status within Europe. The THERAFLEX MB (TMB) procedure is a robust, well standardised system lending itself to transfusion setting and meets the current guidelines. The pathogen kill power of the TMB system, like the other available technologies, is not limitless, probably in order of 6 log for most enveloped viruses and considerably less for non-enveloped ones. It does not induce either new antigen or grossly reducing the function and life span of active principle in fresh frozen plasma (FFP). The removal of the residual MB at the end of the process has the beneficial effect of reducing potential toxic impacts. Clinical haemovigilance data, so far, indicate that cell-free MB plasma is effective in all therapeutic setting requiring FFP, besides inconsistent thrombotic thrombocytopenia purpura data, without serious side-effects or toxicity. The current system is in continuous improvement e.g. regarding virus reduction range, illumination device, software used, and process integration in the blood bank setting.     

A novel method of preoperative autologous blood donation with a large volume of plasma for surgery in gynecologic malignancies.

The objective of this study was to establish a novel method of preoperative autologous blood donation (PAD) for surgery of gynecologic malignancies, which requires considerable amounts of plasma relative to the red blood cell component. To collect a double volume of plasma over the amount obtained from whole blood without using an aphaeresis system, we first collected 500 ml of whole blood (2.5 units), and centrifuged it. We gave back the resultant red cell component alone, and retained the plasma component. We further collected an additional 500 ml of whole blood, and centrifuged it. The red cell component (2.5 units) was stored in the refrigerator (as a concentrated red cell, CRC). The resultant plasma together with the plasma collected first (5 units) was frozen and stored in the freezer (fresh frozen plasma, FFP), We repeated this procedure at most three times at intervals of 1 week. Erythropoietin was injected once a week and iron tablets were prescribed. Ninety-nine patients undergoing surgery for a gynecological malignancy were subjected to this method and 86 patients without PAD served as a control. We conducted the procedure for PAD without any noticeable side effects. The amount of actual use of allogeneic CRC and FFP were significantly reduced in the PAD group compared with the control group. In particular, 93.6% of the PAD cases who gave 10 or less units of FFP could go without allogeneic FFP. Postoperative serum albumin levels were higher in the PAD group compared with the control. We have established a novel PAD method which can yield a greater volume of FFP relative to CRC, thus meeting requirements for surgery for gynecological malignancies.     

维生素C对病毒灭活中血浆蛋白活性的保护效应

本研究探测在亚甲蓝（methyrlene blue，MB）光化学法处理单份血浆过程中，加入维生素C（vitamine C，Vitc）是否影响病毒的灭活效果，是否对血浆蛋白活性成分具有保护作用。用水泡性口炎病毒（vesicular stomatitis virus，VSV）作为指示病毒，在人血浆中加入不同浓度Vit C和终浓度为1μmol／L的亚甲蓝，应用40000lx荧光强度照射并于不同时间取样检测。以细胞病变效应评价对VSV的灭活效果，用RT-PCR检测病毒核酸的变化，并采用Clauss法、一期法和微量免疫电泳等方法对亚甲蓝光化学法处理前后的血浆蛋白含量和活性进行分析。结果发现，VSV血浆在加入240μmol／LVitC并经MB-光照60分钟后，病毒滴度下降〉8 lg TCID50／ml；RT-PCR法也检测不到病毒核酸；血浆中的纤维蛋白原和凝血因子Ⅷ的回收率分别为83.55％和81、67％，与不加Vit C进行亚甲蓝光化学法处理结果相比有显著提高（P〈0.05）；微量免疫电泳显示，血浆中的大部分蛋白成分含量没有明显改变，免疫原性也未受到明显影响。结论：血浆中加入一定量的Vit C不仅不影响亚甲蓝光化学法对病毒的灭活效果，而且有效地保护了血浆蛋白活性成分，因此Vit C可作为亚甲蓝光化学法处理血浆时的保护剂，能有效地提高单份新鲜冷冻血浆的质量。