| 17524094 |
Humpe A, Jansen P, Tischer BK, Schubert S, Beck C, Adamzik ID, Maas JH, Strate A, Gramatzki M, Riggert J: Cryopreservation of cellular products in a closed-bag system with an incorporated dimethyl sulfoxide-resistant sterile filter outside of cleanroom facilities. Transfusion. 2007 Jun;47(6):1033-41.
BACKGROUND: Manipulations, for example, cryopreservation, of cellular therapeutics carried out in an open system must be performed in a class A environment with surrounding class B environment. To avoid cleanroom facilities, a new closed-bag system with an incorporated dimethyl sulfoxide-resistant sterile filter for cryopreservation of cellular products was evaluated at two different centers. STUDY DESIGN AND METHODS: A total of 44 different products (22 buffy coats [BCs] and 22 leukapheresis [LK] products) were split and cryopreserved in parallel in cleanroom facilities (Method I) and with the closed system on the bench of a "normal" laboratory (Method II). Viability analyzed by 7-aminoactinomycin D staining and flow cytometric analysis and sterility of the products were analyzed. RESULTS: Independent of the cellular source (BC or LK), the median viability of CD45+ cells decreased significantly (p < 0.01) during cryopreservation: namely, in BCs, -15.8 percent with both methods, and in LK products, -5.4 percent with Method I and -4.8 percent with Method II, respectively. CD3+ as well as CD14+ cells exhibited a similar pattern and were also found significantly (p < 0.01) diminished after thawing independent of the handling system. For CD19+ cells, the small decrease of viability was only for the BC group significant (p = 0.027) when the cells had been processed with Method I. No bacterial contamination was detected neither in fresh products nor in products after cryopreservation. CONCLUSION: The closed system for cryopreservation of cellular products appears to be equivalent to cleanroom-based methods regarding cellular integrity and sterility when appropriate quality of sterile filters is assured. |
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