In vivo stability of cryoprecipitate fibrinogen

Because of its lower hepatitis risk, cryoprecipitate has been advocated as a substitute for commercial fibrinogen. Previous literature on cryofibrinogen has demonstrated a short blood t1/2, rendering it unsuitable for therapeutic use. The in vivo clearance of 131I- cryoprecipitate was compared with that of 125I-standard fibrinogen. A small amount of cryoprecipitate was rapidly cleared and apparently was cryofibrinogen. However, the bulk of the cryoprecipitate was cleared with a normal half life, as was cryoprecipitated that was in 10-bag pools. The data indicated cryoprecipitate was an effective in vivo form of fibrinogen and thus the preferred fibrinogen source because of its combining normal t1/2 with single donor procurement.     

Comparison of coagulation factor XIII content and concentration in cryoprecipitate and fresh-frozen plasma

BACKGROUND: For patients with plasma coagulation factor XIII (pFXIII) deficiency, recommended means of replacement include infusions of fresh‐frozen plasma (FFP), cryoprecipitate, or (where available) factor (F)XIII concentrates. Quantitative differences in pFXIII concentration in FFP and cryoprecipitate are not well defined and were, therefore, the subject of this study. STUDY DESIGN AND METHODS: FFP and cryoprecipitate (10 bags each from blood group O donors) were analyzed to quantify pFXIII activity and antigen. Coagulation FVIII, fibrinogen, and von Willebrand factor (VWF) were also quantitated. RESULTS: Mean (±SD) pFXIII activity in cryoprecipitate and FFP bags was 60 ± 30 and 288 ± 77 U per bag, respectively, and pFXIII antigen and activity levels were concordant. Other comparisons (mean ± SD) between cryoprecipitate and FFP, respectively, were as follows: coagulation FVIII activity, 133 ± 37 and 265 ± 83 U per bag; fibrinogen content (Clauss kinetic assay), 183 ± 44 and 725 ± 199 mg per bag; VWF antigen content, 181 ± 53 and 218 ± 70 U per bag; VWF ristocetin cofactor activity, 168 ± 34 and 221 ± 65 U per bag; VWF collagen‐binding activity, 164 ± 40 and 208 ± 71 U per bag; and fluid (plasma) volumes per bag, 21.3 ± 2.7 and 245 ± 29 mL. CONCLUSION: In contrast to other cryoprecipitable coagulation proteins, pFXIII is only mildly enriched in cryoprecipitate when compared with FFP (approx. two‐ to threefold). Although both products can provide effective pFXIII replacement, FFP may be preferred when infusion volume is not a major consideration and pFXIII concentrates are not available. VWF is substantially enriched in cryoprecipitate (approx. ninefold compared with its concentration in FFP), with VWF activity content exceeding that of FVIII by approximately 26 percent on average.     

Modulation of plasma fibrinogen levels in acute-phase response after hepatectomy.

In acute-phase response, the use of amino acids is redirected to supporting the synthesis of proteins for host defence and tissue repair. Fibrinogen is one of these proteins, and its plasma levels commonly increase in acute-phase conditions. After hepatectomy, this pattern may be modified by the variable impact of postoperative liver dysfunction. Our study was performed to specifically assess and quantify this aspect. Data were collected prospectively on 82 hepatectomized patients; 62 recovered normally, 20 had major complications (most commonly sepsis). Plasma fibrinogen and a large series of complementary variables were determined preoperatively and at postoperative days 1, 3 and 7 in all patients and until recovery, or death in those with complications. Multiple regression analysis showed that postoperative changes in fibrinogen (deltaFIB, micromol/l) were simultaneously related to the number of resected liver segments (NSEG), total bilirubin (BIL, micromol/l), aspartate aminotransferase (AST, U/l, n.v. 5-45), albumin (ALB, g/l), prothrombin activity (PA, % of standard reference), age (AGE, years) and basal preoperative fibrinogen (PFIB, micromol/l): deltaFIB = -0.51(NSEG) - 0.71(Log(n)BIL) - 0.74(Log(n)AST) + 0.11(ALB) + 0.09(PA) - 0.06(AGE) - 0.55(PFIB) + 7.74 (n=362, r2=0.68, p<0.001). In addition, an early postoperative tendency for low fibrinogen was associated with the subsequent development of complications or death. Our study quantifies the impact of size of hepatectomy and dysfunction of residual liver in modulating postoperative fibrinogen level and suggests that failure of fibrinogen to increase may signal an unfavorable condition limiting up-regulation of acute-phase response and increasing liability to complications.     

Fibrinogen content of low-volume cryoprecipitate

Single-donor cryoprecipitate is the most convenient and reliable source of fibrinogen. A change by the regional Red Cross Blood Service to the production of low-volume cryoprecipitate led the authors to reexamine the fibrinogen content of cryoprecipitate units. The average fibrinogen content of individual low-volume (4 ml) units (n = 23) was 101 +/− 48 mg; in the 10-unit pools (n = 9 pools), content was 89 +/− 13 mg. Both measurements were considerably lower than previously published. By contrast, the mean fibrinogen content of regular-volume (15 ml) cryoprecipitate units (n = 8) was 142 +/− 50 mg. The fibrinogen was stable for at least 4 hours after thawing, and it survived refreezing and thawing.     

Comparison of cryoprecipitate with fibrinogen concentrate for acquired hypofibrinogenaemia

BackgroundThe benefits of fibrinogen concentrate in hypofibrinogenaemia have been established in congenital and has been used in acquired disorders. Most European countries have already changed their practice, using fibrinogen concentrate.MethodsWe compared the use of fibrinogen concentrate in acquired hypofibrinogenaemia to cryoprecipitate, which continues to be the standard of care in the UK. We undertook a retrospective analysis of fibrinogen increment in patients treated for acquired hypofibrinogenaemia.ResultsSixty four transfusion episodes receiving cryoprecipitate and 36 episodes receiving fibrinogen concentrate were compared. The median increment following 10 donor pools (two bags) of cryoprecipitate was 0.26 g/l, compared to 0.44 g/l following 2 g of fibrinogen concentrate.ConclusionWith its superior safety profile from infectious diseases, this provides further evidence to support the use of fibrinogen concentrate.     

Postfiltration factor VIII and fibrinogen levels in cryoprecipitate stored at room temperature and at 1 to 6 degrees C

The 13th edition of the standards of the American Association of Blood Banks specified storage at 1 to 6 degrees C for cryoprecipitated anti-hemophilic factor (Cryo) administered up to 6 hours after thawing if the Cryo is used for factor VIII (FVIII) content (Standard J4.210). Previous editions specified room-temperature (RT) storage for up to 6 hours. Currently, the temperature specification has been deleted. There are few data addressing the optimal storage temperature and maximum storage time for FVIII and fibrinogen in thawed Cryo. Thirty bags of Cryo were assayed for FVIII and fibrinogen. Each bag was divided into two aliquots; one was stored at RT and the other at 1 to 6 degrees C. Assays were performed immediately after thawing (Base) and 6 and 24 hours after thawing, respectively. All samples were filtered through 200-mu blood component infusion sets before assay. Three hundred analyses were performed, 150 each for FVIII and fibrinogen by conventional clotting technique. Data were analyzed by using a paired t test. Cryo stored at 1 to 6 degrees C for 6 and 24 hours showed an FVIII loss of 35 percent (p less than 0.0001) and 63 percent (p less than 0.0001), respectively. Cryo stored at RT for 6 and 24 hours had an FVIII loss of 8 percent (p greater than 0.05) and 20 percent (p less than 0.0001). Cryo stored at 1 to 6 degrees C for 6 and 24 hours had a fibrinogen loss of 20 percent (p less than 0.0001) and 43 percent (p less than 0.0001). Cryo stored at RT for 6 hours had no fibrinogen loss and a 2 percent loss at 24 hours (p greater than 0.05). These preliminary data show a significant loss of FVIII and fibrinogen activity in Cryo stored at 1 to 6 degrees C and filtered before assay. The FVIII and fibrinogen activity at RT is clearly maintained up to 6 hours after thawing.     

Postthaw stability of fibrinogen in cryoprecipitate stored between 1 and 6 degrees C

The fibrinogen activity in thawed cryoprecipitate stored between 1 and 6 degrees C is maintained essentially unchanged in most bags for a month. Occasionally, a bag will have a reduction in fibrinogen. If pooling has not occurred, thawed cryoprecipitate should be useful as a source of fibrinogen for a period of time considerably in excess of the 6 hours allowed for its use as a source of factor VIII or von Willebrand factor.     

The effects of temperature variations on cryoprecipitate

The effect of temperature on Factor VIII levels in blood and cryoprecipitate was assessed. Freshw collected units of blood required several hours to reach 4 C, but this delay seemed of little importance since equal amounts of cryoprecipitated Factor VIII were recovered from blood stored either at 22 C or at 4 C. Freezing at -80, -60, or −40 C produced identical yields of Factor VIII, whereas freezing at −20 C resulted in significantly lower recoveries. This might be expected if one considers the physiochemical changes that occur during the freezing process.     

Long-term frequent plasma exchange donation of cryoprecipitate

Plasma exchange donation accomplishes the selective donation of cryoprecipitate. It facilitates the repeated donation of large quantities of factor VIII by individual donors and reduces donor exposure for recipients. A highly motivated donor is described who has undergone 103 donations between May 1983 and March 1987, producing 359,460 IU of factor VIII and supplying all the factor VIII needed since August 1983 by his severely affected hemophiliac son, now age 14. The donor has remained in good health, and no significant abnormalities have been noted in hematologic, biochemical, immunologic, coagulation, and serum protein testing. Extensive experience with this donor suggests that repeated plasma-exchange donation is safe and can sometimes allow single-donor support of severe hemophiliacs.     

Antithrombin III in fresh frozen plasma, cryoprecipitate, and cryoprecipitate-depleted plasma

Antithrombin III (AT III) is a plasma protein that inhibits several activated procoagulants. Hereditary disease or acquired conditions such as severe hepatic dysfunction, nephrotic syndrome and intravascular coagulation may be associated with reduced levels of AT III. Its replacement may be essential in controlling thrombosis. In order to determine the most effective form of replacement, we compared AT III biological activity and antigen levels in conventionally prepared fresh frozen plasma, cryoprecipitate and cryoprecipitate depleted plasma (CDP). Both the activity and antigen levels were comparable in all three products (approximately 100%) and AT III was not concentrated in cryoprecipitate. These results indicate that conventionally prepared CDP, fresh frozen plasma and cryoprecipitate contain equal quantities volume for volume of AT III. On this basis, all products are equally effective as therapy for AT III deficiency, but CDP and fresh frozen plasma are recommended as convenient sources of this factor.     

Simple method for correcting total protein in plasma for actual fibrinogen content.

Using plasma instead of serum for routine chemistry analyses has many advantages. To overcome the disadvantage of inclusively measuring fibrinogen in the plasma total protein assay without changing the clinical significance of the total protein assay, we investigated the possibility of subtracting the actual amount of fibrinogen from the plasma total protein. The correlation between serum and plasma total protein was excellent (plasma total protein = 0.989 x serum total protein + 6.7 g/L; r = 0.969; n = 131; mean difference = 5.55 g/L; P < 0.001). When the plasma total protein was corrected for the actual amount of fibrinogen, the correlation with serum total protein was equally good but the intercept was practically eliminated (corrected plasma total protein = 1.009 x serum total protein + 0.25 g/L; r = 0.985; n = 131; mean difference = 0.78 g/L; P = 0.47). The mean concentration of fibrinogen was 2.5 g/L (range: 1.38-3.62 g/L; n = 404) for blood donors, 3.6 g/L (n = 2707) for patients from the outpatient department, 4.6 g/L (n = 2023) for patients admitted to the hospital, and 6.6 g/L (n = 219) for patients whose concentration of C-reactive protein was > 50 mg/L. We conclude that the plasma total protein result should be corrected for the actual amount of fibrinogen.     

病毒灭活新鲜冰冻血浆制备冷沉淀的可行性探讨

目的探讨亚甲蓝光化学法(MB-P)病毒灭活新鲜冰冻血浆制备冷沉淀凝血因子的可行性。方法选取2014年1~6月无偿献血者捐献的400 mL全血93袋,分离新鲜冰冻血浆200 mL后再均分为2袋,各100mL,分别作为对照组和试验组。对照组直接制备冷沉淀凝血因子,试验组经MB-P法病毒灭活后再制备冷沉淀凝血因子。检测每袋冷沉淀凝血因子中FⅧ和Fbg水平。结果对照组FⅧ和Fbg水平分别为(82.9±7.1)IU/100mL、(102.4±8.5)mg/100mL,试验组分别为(56.6±5.3)IU/100mL、(83.3±5.6)mg/100mL,试验组FⅧ和Fbg水平均低于对照组,组间比较差异均有统计学意义(P0.05),且均符合相关国家标准。结论加强血液采集、储存、运输和制备过程中的质量控制,使用经MB-P法病毒灭活新鲜冰冻血浆制备的冷沉淀凝血因子符合相关国家标准。     

Preparation of cryoprecipitate from riboflavin and UV light-treated plasma

Background and objectivesThe Mirasol® pathogen reduction technology system for plasma is based on a riboflavin and UV light treatment process resulting in pathogen inactivation due to irreversible, photochemically induced damage of nucleic acids. This study was undertaken to evaluate the possibility of making pathogen reduced cryoprecipitate from riboflavin and UV light- treated plasma that meets the quality requirements specified by UK and European guidelines for untreated cryoprecipitate.Materials and methodsCryoprecipitate was made from riboflavin and UV light-treated plasma. Plasma units were thawed over a 20 h period at 4 °C, and variable centrifugation settings (from 654 g for 2 min to 5316 g for 6 min) were applied to identify the optimal centrifugation condition. Plasma proteins in cryoprecipitate units were characterized on a STA Compact, Diagnostica STAGO and Siemens BCS analyzer.ResultsNeither the centrifugation speed or time appeared to have an effect on the quality of the final cryoprecipitate product; however the initial solubilization of the cryoprecipitate product was found to be easier at the lower centrifugation setting (654 g for 2 min). Cryoprecipitate units prepared from Mirasol-treated plasma demonstrated protein levels that were less than levels in untreated products, but were on average 93 IU/unit, 262 mg/unit and 250 IU/unit for FVIII, fibrinogen and von Willebrand ristocetin cofactor activity, respectively.ConclusionCryoprecipitate products prepared from Mirasol-treated plasma using a centrifugation method contain levels of fibrinogen, FVIII and von Willebrand ristocetin cofactor activity, that meet both the European and UK guidelines for untreated cryoprecipitate. Flexibility in centrifugation conditions should allow blood banks to use their established centrifugation settings to make cryoprecipitate from Mirasol-treated plasma.     

Modulation of macrophage responsiveness to lipopolysaccharide by IRAK-1 manipulation

Local activation of the macrophage by endotoxin is essential for the eradication of invasive gram-negative infections. Circulating endotoxin at lower concentrations results in immune cell activation at distant sites leading to tissue injury. Although the cellular mechanisms involved in these potentially dissimilar events are incomplete, it appears that the proximal kinase IRAK-1 plays a role. Thus, sense and antisense IRAK-1 oligonucleotides were used to determine the role IRAK-1 plays in macrophage activation by systemic (1-100 ng/mL) and local (1000 ng/mL) concentration of lipopolysaccharide (LPS) within THP-1 cells. Within the sense group, 1-1000 ng/mL of LPS within the sense group resulted in cellular activation of ERK-1/2, p38, and JNK/SAPK and the nuclear activation of NF-kappaB and AP-1. This activation was associated with proinflammatory cytokine production and cellular spreading. Systemic concentrations of LPS within the antisense group were associated with significant attenuation of intracellular signaling, cytokine production, and cellular spreading compared with the sense group. Local concentrations of LPS within the antisense group, however, were associated only with a delay in intracellular signaling, with no effect on cytokine production or cell spreading compared with the sense group. Based on these results, it appears that IRAK-1 is essential to macrophage activation at systemic, but not local, concentrations of LPS. These data suggest that redundant pathways exist that are functional at higher concentrations of LPS. Therefore, IRAK-1 appears to be the central kinase involved in the activation of the macrophage at distant sites during septic shock but is not necessary for activation in areas of local infection.     

血浆制备时间和速冻方法对冷沉淀凝血因子质量的影响

目的探讨新鲜血浆的制备时间和速冻方法对冷沉淀凝血因子质量的影响,选择合适的制备时间和速冻方法。方法随机抽取制备时间分别为2 h、4 h、6 h、8 h新鲜血浆各16人(份),采用无菌接驳机平均分为A、B两实验组,分别用平板速冻机和传统低温冰箱速冻制备新鲜冰冻血浆(FFP);在相同条件下分别对两组FFP制备冷沉淀;采用凝固法检测两组冷沉淀的凝血因子Ⅷ(FⅧ)和纤维蛋白原(Fg)。结果血浆制备时间为2 h、4 h、6 h、8 h的冷沉淀FⅧ活性(IU)A组分别为78.40±22.87、74.06±23.72、71.25±19.93、70.53±18.84,B组分别为66.60±17.12、58.08±18.19、52.57±12.26、51.19±12.51。A、B组冷沉淀FⅧ随着制备时间的延长,均呈下降趋势,相同制备时相A与B组比较均有统计学差异(P<0.05);A组FⅧ活性4个制备时相间比较差异无统计学意义(P>0.05),B组2 h与6 h、8 h比较差异均有统计学差异(P<0.05)。血浆制备时间为2 h、4 h、6 h、8 h的冷沉淀中Fg含量(mg)A组分别为114.53±24.76、117.62±27.61、114.44±22.84、120.23±26.48,B组分别为113.36±23.53、116.43±25.38、115.28±23.66、117.92±25.58,Fg含量在不同制备时间和速冻方法条件均无统计学差异。结论 8 h内制备血浆2种速冻方法均能满足冷沉淀质量要求,平板式速冻机制备血浆的冷沉淀FⅧ活性显著性高于传统低温冰箱。     

冷上清做置换液血浆置换治疗血栓性血小板减少性紫癜

目的　观察新鲜冰冻血浆制作冷沉淀后的上清液 (冷上清 )治疗血栓性血小板减少性紫癜 (TTP)的临床效果。方法　用冷上清作置换液 ,对患者作血浆置换 ,置换后症状缓解 ,继续以冷上清输注 ,配合激素、免疫抑制剂、抗血小板聚集药物治疗。结果　 1 0名患者中 ,9名各置换 3～ 6次 ,1名因反复发作 3次 ,共置换 1 0次 ;8名治愈 ,2名死亡。结论　应用冷上清作置换液血浆置换治疗TTP ,与用新鲜冰冻血浆作置换液有同样的效果。且当新鲜冰冻血浆输注无效时 ,应用冷上清后也可获得缓解