Cryoprecipitate Fibrinogen Research Articles

Effect of Water Bath versus Refrigerator Thaw on Cryoprecipitate Fibrinogen and Factor VIII Content Using a Pre-Pooled Plasma Experimental Approach

<b><i>Introduction:</i></b> Originally developed as a form of factor VIII concentrate, cryoprecipitate’s primary clinical use has changed to treat fibrinogen deficiency as highlighted by recent approval of pathogen-reduced cryoprecipitated fibrinogen concentrates. The methodology by which frozen plasma is thawed during cryoprecipitate manufacturing is not standardized. This study compared plasma thawing techniques on cryoprecipitate fibrinogen and factor VIII levels. <b><i>Methods:</i></b> A matched pairwise experimental design was employed across three experiments to compare plasma thawing approaches (water bath or 24–48 h refrigerator). Each experiment involved the creation of 10 sets of ten homogenous frozen plasma pools which were then used to manufacture 10 pairs of cryoprecipitate pools differing only by assigned plasma thawing method. Total cryoprecipitate fibrinogen and factor VIII content between plasma thawing methods were compared using matched <i>t</i>-testing within each experiment. <b><i>Results:</i></b> Compared to water bath thawing, 24-h refrigerator thawing led to significantly higher cryoprecipitate fibrinogen content (2,554 mg vs. 1,824 mg; <i>p</i> < 0.001) and significantly lower cryoprecipitate factor VIII content (601 IU vs. 709 IU; <i>p</i> < 0.001). Longer refrigerator thaw times (36 and 48 h) led to significantly higher cryoprecipitate fibrinogen content than 24-h refrigerator thaw (3,180 mg vs. 2,956 mg and 2,893 mg vs. 2,483 mg, respectively; <i>p</i> = 0.01–0.03). <b><i>Conclusion:</i></b> Using homogenous frozen plasma units in a matched pairwise experimental design, refrigerator plasma thawing led to superior cryoprecipitate fibrinogen yields and inferior cryoprecipitate factor VIII yields. When maximizing cryoprecipitate fibrinogen yields, refrigerator plasma thawing, and in particular longer thawing times (36–48 h), should be considered.

The Amount of Fibrinogen in Cryoprecipitate by In-hospital Preparation

The Amount of Fibrinogen in Cryoprecipitate by In-hospital Preparation

Fibrinogen replacement in trauma haemorrhage

Fibrinogen replacement in trauma haemorrhage

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.

Modulation of fibrinogen content in cryoprecipitate by temperature manipulation during plasma processing.

In routine blood bank production of single-donation cryoprecipitate, the introduction of a 16-hour hold at 4 degrees C, with the frozen plasma units packed into polystyrene containers, resulted in plasma prethaw temperatures of -4 degrees C to -8 degrees C. This in turn resulted in cryoprecipitate fibrinogen levels that were 214 percent of those obtained when units were thawed immediately after removal from -30 degrees C storage. In scale-model production of factor VIII concentrate, plasma warmed from -30 to -10 to -15 degrees C over 18 hours before pooling and thawing yielded cryoprecipitate fibrinogen levels that were 66 percent of those found in plasma warmed to -2 to -5 degrees C over the same period. Processing -30 degrees C plasma without a warming period led to cryoprecipitate fibrinogen levels that were 40 percent of those obtained from plasma warmed to -2 to -5 degrees C. These differences were accentuated after purification of the cryoprecipitates to an intermediate-purity factor VIII concentrate. These results suggest that simple modifications in production methods allow the fibrinogen content of cryoprecipitate to be tailored to specific uses.

Postthaw stability of fibrinogen in cryoprecipitate stored between 1 and 6°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.

Variability in the Fibrinogen and Von Willebrand Factor Content of Cryoprecipitate: Implications for Reducing Donor Exposure

Advances in the preparation of commercial Factor VIII concentrates have decreased the clinical use of cryoprecipitate to replace Factor VIII coagulant activity. Cryoprecipitate is now frequently transfused as a source of fibrinogen or von Willebrand factor (vWF). The minimum acceptable content of Factor VIII is prescribed, but no attempt is made to optimize, standardize, or assess the content of fibrinogen or vWF in cryo. If reasonably accurate information on the composition of cryoprecipitate were available, the physician could calculate an appropriate dose of cryo, thus avoiding unnecessary donor exposures and waste of product. This study was designed to measure the functionally active vWF and fibrinogen in cryoprecipitate prepared by three techniques in an attempt to optimize the yield of these hemostatically important components, and to obtain accurate information on the composition of the product. Cryoprecipitate was made from 82 units of fresh frozen plasma (FFP) as follows: (1) most of the supernatant plasma was expressed from "dry" cryo; (2) about 15 mL of plasma was left in each "regular" unit; and (3) "overnight" units were made from FFP thawed overnight in a refrigerator rather than in a 4 degrees C water bath as for the dry and regular units. Dry, regular, and overnight units had volumes of 8.8 +/- 1.5, 16.6 +/- 3.9, and 15.1 +/- 2.4 mL/bag, respectively. Dry cryoprecipitate units had significantly less fibrinogen and vWF than regular or overnight units. The vWF multimer pattern for all three types of cryoprecipitate was indistinguishable from that of normal pooled plasma. Thus, the amount of plasma expressed during preparation has a significant impact on the vWF and fibrinogen content of the resulting product. The amounts of these clinically important proteins should be assayed as a step toward rational determination of optimal cryoprecipitate doses in specific clinical settings.

The use of fibrin glue in intracranial procedures: Preliminary results

Intracranial procedures always have the potential of cerebrospinal fluid (CSF) leakage postoperatively. Sealing all routes of CSF drainage to the outside of the intracranial contents is essential. This is usually achieved with muscle and fat plugs, homograft dura, fascia, and suture. The use of a fibrin glue might affect and lessen the likelihood of a CSF leak. Eight clinical cases of various intracranial procedures using a simple, two-part patient autologous cryoprecipitate fibrinogen and bovine thrombin glue are described. Preliminary results of up to 1 year show no CSF leakage nor adverse reactions to the fibrin glue. The production method and material characteristics are briefly compared with other currently described autologous fibrin glue formulations. This version is similar in strength to other formulations, yet is simpler and more convenient to produce. The use of this autologous fibrin glue appears to provide an adjunct to commonly employed packing techniques in a convenient and effective manner. With more experience, fibrin glue might become an even more important tool in intracranial procedures.

A heat-treated factor VIII concentrate prepared by controlled-pore glass adsorption chromatography.

Four years' experience with a method for preparing a high-purity, low-fibrinogen, heat-treated factor VIII concentrate is reported. The process, batch adsorption of a cryoprecipitate extract with controlled-pore glass granules, removes 77 percent of the cryoprecipitate fibrinogen, resulting in a final concentrate-specific activity of 0.74 IU factor VIII per mg of protein at a yield of 194 IU factor VIII per kg of starting plasma. Heat treatment of the lyophilized concentrate for 72 hours at 60 degrees C results in less than 10 percent loss of factor VIII activity. This process does not require expensive fractionation equipment, is suitable for small-to medium-scale batch concentrate production and could be adopted by moderately well-equipped regional blood processing laboratories for the decentralized production of a high-quality, heat-treated factor VIII concentrate.

Cryoprecipitate-topical thrombin glue: Initial experience in patients undergoing cardiac operations

The use of fibrin glues as topical hemostatic agents is reported in the European literature. We have composed an analogous compound in our operating rooms using cryoprecipitate and topical thrombin (1000 units/ml) in equal volumes applied directly to the bleeding site. We have used cryoprecipitate-topical thrombin glue in 26 patients undergoing cardiac operations. Severe bleeding not responding to usual methods of control was encountered during or after coronary artery bypass (n = 17), valve replacement (n = 3), bypass plus valve replacement (n = 5), or repair of postinfarction ventricular septal defect (n = 1). Five patients were operated on emergently and four were undergoing their second cardiac operation. The glue was used in four patients while on bypass and fully heparinized and in 17 patients who continued to bleed after separation from bypass and administration of protamine. Hemostasis was achieved in all patients and none required reexploration for bleeding. In five patients undergoing reexploration for postoperative hemorrhage (none having received cryoprecipitate-topical thrombin glue during the initial operation), the glue provided hemostasis when other measures failed, and no additional reexplorations were needed. No patient exhibited hypersensitivity, fibrinolysis, or coagulopathy following the use of this glue. In 16 patients followed for 9 to 12 months postoperatively, no hepatitis has occurred. The highly concentrated fibrinogen in cryoprecipitate is activated by thrombin to form fibrin and bring about rapid hemostasis. Cryoprecipitate-topical thrombin glue is a readily available, reliable, and inexpensive topical hemostatic agent in the patient undergoing a cardiac operation.

The role of fibronectin in factor VIII/von Willebrand factor cryoprecipitation

To evaluate the role of fibronectin (Fn) in factor VIII (FVIII) and von Willebrand factor (vWf) cryoprecipitation, factor VIII procoagulant activity, factor VIII coagulant antigen, factor VIII-related antigen and von Willebrand ristocetin cofactor activity were measured in cryoprecipitate and cryosupernatant from normal and Fn-depleted plasmas. Following cryoprecipitation of normal plasmas, most of the FVIII and almost all the FvWf recovered were found with a part of Fn and of fibrinogen in cryoprecipitate. Fn-depleted plasmas prepared either by affinity chromatography on gelatin or by immunoadsorption on monoclonal anti-Fn antibodies behaved differently : although their cryoprecipitate contained normal fibrinogen levels, neither FVIII nor FvWf was precipitated. Experiments performed with Fn-depleted plasma to which purified fibronectin had been added, and samples of plasma with decreased Fn levels (0.01 to 0.2 g/l) suggest that there is a relation between initial Fn level and the extent of FVIII/vWf cryoprecipitation. We conclude that Fn, like fibrinogen, is necessary to induce cryoprecipitation of FVIII/vWf and that an initial plasma level of 0.2 g/l is sufficient to obtain good recovery of FVIII/vWf in cryoprecipitate.

Fibrinogen in cryoprecipitate and its relationship to factor VIII (AHF) levels.

Very little has been published to indicate the quantity of fibrinogen in cryoprecipitates. We assayed 88 preparations from five blood banks for factor VIII(AHF) and fibrinogen to assess whether the AHF assay can predict the fibrinogen content. Cryoprecipitate was considered to be consistent with FDA standards with 80 units of factor VIII/bag (40% yield from 200 ml plasma). Fibrinogen was considered adequate if 200 mg were recovered (40% yield, 200 ml plasma, normal range 150--350 mg/dl). The mean AHF was 145 units/bag and fibrinogen. In 64/88 bags, the fibrinogen and AHF were concordant, but in 24/88 bags the results were discordant. Although it appears safe to conclude that a bag of cryoprecipitate will average 250 mg fibrinogen, adequate control may require separate assays for fibrinogen.