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B Medical Systems Contact Shock Freezers: Rapid Freezing of plasma for the optimal recovery of Factor VIII

Fresh Frozen Plasma is an important raw material for the production

of coagulation factor concentrates for patients with hemorrhagic

disorders. Since coagulation Factor VIII (FVIII:C) is the most labile

CSFRANGE

hemostatic protein, the freezing process of the plasma needs to be

optimized for the best yield of Factor VIII. This paper discusses the

recommendations made by the existing medical and scientific literatures

concerning the freezing time of plasma along with Good Manufacturing Practices

(GMP) and the average freezing time of the Contact Shock Freezers (CSF) developed by B Medical Systems.

It was found that the Contact Shock Freezers developed by B Medical Systems were able to freeze 30 units

and 48 units of 350ml bags in approximately 26 minutes, well within the permissible ranges preventing any

substantial loss of Factor VIII in frozen plasma.

BACKGROUND

Human plasma is a blood component obtained from the fractionation of whole blood (whole-blood plasma [WBP]) or by apheresis collection (apheresis plasma [AP])[1] and is that part of the blood that contains all the clotting factors, as well as other blood proteins. Transfusion of fresh-frozen plasma (FFP) replaces deficiencies of multiple coagulation factors and controls proteins in massive blood loss, liver disease, and disseminated intravascular coagulation[2], making FFP an important raw material for the production of coagulation factor concentrates for patients with haemorrhagic disorders. In order to minimize the loss of coagulation activity, the production process of factor concentrates has to be optimised[3]. Since coagulation Factor VIII (FVIII:C) is a labile hemostatic protein, care needs to be taken to avoid reduction in FVIII activity during the manufacturing practices.

OBjeCtive

Even though there are multiple factors influencing the recovery of coagulation factors- in order to understand the impact of Contact Shock Freezers on the quality of frozen plasma, it is critical to focus on the impact of plasma freezing time on the Factor VIII recovery. Hence, the objective of this paper is to understand the best practices recommended by the existing medical and scientific literature on the impact of freezing time on Factor VIII recovery and Good Manufacturing Process (GMP) associated with plasma freezing. As a part of this study, the average freezing time of the Contact Shock Freezers (CSF) developed by B Medical Systems, was tested to understand its effectiveness related to their adherence to the industry benchmarks in plasma freezing.

01 | 03 B Medical Systems

02 | 03 B Medical Systems

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the Medical Literature: In an international forum published in 1983[4], Freidli and co-workers demonstrated that slow freezing results in the formation of a cryoprecipitate, which has about twice the weight of cryoprecipitate that is obtained by fast freezing. Based on the recommendations of this forum, plasma should be completely frozen within 30 minutes. In the same forum, Stryker and co-workers declared that quick and uniform freezing of plasma is essential for optimal recovery of FVIII:C for fractionation into anti-haemophilic factor concentrates. G. Carlebjork et al[5] proved higher purity of cryoprecipitate expressed as factor VIII/Fibrinogen (IU/mg) and as FVIII/vWF:Ag(IU/IU) could be shown when the plasma freezing time was reduced. Cryoprecipitate purity measured as a factor to FVIII to fibrinogen ratio increased from 0.50 to 0.82 (IU/mg) when the freezing time was decreased from 10 hours to 45 minutes. (Table 1)

A.M. Swärd-Nilsson et al[3], showed that freezing times of 4 hours or more cause asignificantly more pronounced fall of FVIII:C in plasma as compared to freezing timesof 60 minutes or less (Fig 1), bringing to the conclusion that a shorter freezing timeis therefore advantageous in order to avoid unnecessary loss of FVIII activity.

Good Manufacturing Practices (GMP): The 18th Edition of EDQM[6] mentions that for the preparation of fresh frozen plasma (both from whole blood and by apheresis), the freezing must take place in a system that allows complete freezing within one hour to a temperature below -30°C.

Contact Shock Freezers by B Medical Systems: Contact Shock Freezers by B Medical Systems- CSF61 and CSF101, are designed for the fast cooling of plasma bags to a core temperature of -30°C. In order to understand the average freezing time, the CSF101 and CSF61 were pre-cooled to -52°C at +25°C ambient temperature and once the pre-cooling phase was completed, the bags prepared with the saline solutions were placed on the cooling plates and the freezing process was started. Once the freezing cycle was completed, these bags were removed from the cooling plates. The experiment was repeated a number of times to estimate the average freezing time. The average freezing times calculated were as follows:

Plasma Freezing Time (h)

CryoprecipitateFVIII/

FVIIIR:Ag (IU)FVIII/

Fibrinogen Ratio

10 0.46 ±0.04 0.50 ±0.06

2.5 0.59 ±0.04 0.71 ±0.07

0.7 0.65 ±0.06 0.82 ±0.05All results are mean ± SEM

CSF61 CSF101

Freezing time to core temperature of -30°C at +25°C ambient temperature (in single layer) 30 units (350ml) ± 26 min. 48 units (350ml) ± 26 min.

MethODOLOGy

An intensive scientific and medical literature review was conducted to understand the existing standards and industry practices associated with freezing of plasma. The scope of the study was limited to the literature related to the impact of freezing time/rate of plasma on the recovery of Factor VIII. In order to understand the average freezing time of the Contact Shock Freezers developed by B Medical Systems, both CSF61 and CSF101 were used. 48 units of 350ml plasma bags were filled with 0.9% NaCl solution for testing CSF101. Similarly, 30 units of 350ml plasma bags were filled with 0.9% NaCl solution for testing of CSF61. The testing method used was the ‘Bag Sandwich’ method, where the thermocouples are sandwiched between two bags, each filled with half the target volume, which is the usual process of freeze time validation in the blood centres.

ReSULtS

Source: Carlebjörk G, Blombäck M, Pihlstedt P: Freezing of plasma and recovery of factor VIII. Transfusion 1986; 26:159–162

Source: A.-M. Swärd-Nilsson, P.-O. Persson, U. Johnson & S. Lethagen. Factors influencing factor VIII activity in frozen plasma. Vox Sanguinis (2006)90, 33–39

Table 1: Quality of cryoprecipitate made

from plasma frozen at various rate

Fig 1: Recovery of FVIII:C kept for 2 h at room temperature,

followed by freezing at freezing times of 0.5 h (A2), 1 h (B2),

4 h (C2) and 24 h (D2). Plasma kept for 4 h (B4) and 6 h (B6)

in room temperature followed by freezing

at a freezing time of 1 h

A2 B2 C2 D2 B4 B6

2.2

1.7

1.2

0.7

FVIII

:C IU

/ml

CSF61 CSF101

B Medical Systems S.à r.l.

17, op der Hei L - 9809 Hosingen, Luxembourg

Tel. : (+352) 92 07 31 - 1 Fax : (+352) 92 07 31 - 300 info@bmedicalsystems.com www.bmedicalsystems.com

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This paper is based on the standard testing conditions at the B Medical Systems manufacturing plant at Hosingen, Luxembourg. However these functionalities are subject to change without prior notice. This paper is for informational purposes only. All indications without guarantee and excluding all liability due to faulty, incomplete or outdated information. All technical data subject to change without prior notice. B Medical Systems and the B Medical Systems logo are trademarks or registered trademarks of B Medical Systems S.à r.l.

CONCLUSiON

Human plasma is an important transfusion component and also functions as a raw material for the manufacturing of coagulation factor concentrates, especially Factor VIII. Existing literature has proved that the freezing process of the plasma affected Factor VIII recovery, with slow freezing rate having a deleterious effect on the Factor VIII recovery. The literature also recommends that quick and uniform freezing of plasma is essential for optimal recovery of FVIII for fractionation into anti-haemophilic factor concentrates with rapid plasma freezing preventing substantial loss of Factor VIII. Even though, each of the studies mentioned in this paper, have showed varying ideal freezing times, there is one conclusion that can be drawn from these reviews - That the fastest you can freeze plasma, the ideal it is, with the maximum permissible freezing time being 60 minutes. The European Pharmacopeia also recommends that plasma should be frozen to -30°C or below to bring the core temperature down to -30°C within one hour. Contact Shock Freezers developed by B Medical, CSF61 and CSF101 have shown average freezing times of approximately 26 minutes when tested using 30 units (for CSF61) and 48 units (for CSF101) of 350ml bags filled with 250ml saline solution. This is well within the permissible range recommended by the medical standards, which proves the fact that CSF101 and CSF61 help in the production of high quality frozen plasma by aiding in the optimal recovery of Factor VIII.

Want to know more about the Contact Shock Freezer developed by B Medical Systems?

Contact us at info@bmedicalsystems.com

Sources:

[1] Giuliano Grazzini , Giuseppe Rossi , Daniela Rafanelli, Davide Gambelli, Claudio Farina, Filippo Mori, Paolo Zucchelli, Giorgio Marchiori, Antonio Breda, Giancarlo Maria Liumbruno, Quality control of recovered plasma for fractionation: an extensive Italian study. Transfusion, 08 July 2008

[2] O’Shaughnessy DF, Atterbury C, Bolton MP, et al. British Committee for Standards in Haematology, Blood Transfusion Task Force. Guidelines for the use of fresh-frozen plasma cryoprecipitate and cryosupernatant. Br J Haematol. 2004; 126:11–28

[3] A.-M. Swärd-Nilsson, P.-O. Persson, U. Johnson & S. Lethagen. Factors influencing factor VIII activity in frozen plasma. Vox Sanguinis 2006; 90:33–39

[4] Allain JP, Friedli H, Morgenthaler JJ, Pflugshaupt R, Gunson HH, Lane RS, Myllylä G, Rock GA, Stryker MH, Woods KR: International Forum: What are the critical factors in the production and quality control of frozen plasma intended for direct transfusion or for fractionation to provide medically needed labile coagulation factors. Vox Sang 1983; 44:246–259

[5] Carlebjörk G, Blombäck M, Pihlstedt P: Freezing of plasma and recovery of factor VIII. Transfusion 1986; 26:159–162

[6] Guide to the preparation, use and quality assurance of Blood Components: European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS): EDQM 18th Edition 2015