Modalités de préparation, cryopréservation, décongélation des cellules souches hématopoïétiques et précautions pour infusion au patient : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC)

Study of a new device for washing and concentrating cryopreserved hematopoietic stem cells and mononuclear cells: a single center experience

BACKGROUND AIMS

Cryopreserved cellular products, as parts of hematopoietic progenitor cell (HPC) transplants, mononuclear cell reinjections for donor lymphocyte infusion or extracorporeal photopheresis, can be washed before being reinjected into the patient or infused directly, depending on local practices. The aim of washing is to reduce the incidence and severity of adverse reactions (ARs) due to the dimethyl sulfoxide (DMSO) used as a cryoprotective agent and other factors, such as dead cell debris. At the authors' cell therapy laboratory (CTL) in Poitiers, France, as in 76% of Etablissement Français du Sang (EFS) CTLs, all cryopreserved products undergo thawing in a water bath followed by washing with the COBE 2991. As this device will soon cease to be available, an alternative process needs to be assessed.

METHODS

The authors compared two closed systems: the authors' semi-automatic system using the traditional centrifugation method (COBE 2991) and an automated device using spinning membrane filtration (Lovo). A total of 72 HPC bags available for research were used. The authors first performed a paired comparison, processing one or two HPC bags washed by each device. A second study was carried out to compare two different washing solutions generally used by EFS CTLs along with variable storage conditions. Finally, the authors studied the efficiency of the Lovo with three or four thawed bags. The main parameters studied were viable CD34+ cell recovery and viability, CD3+ cell recovery, stability up to 6 h after washing, DMSO elimination and center feasibility.

RESULTS

The Lovo device showed better CD34+ cell recovery compared with the COBE 2991 while maintaining CD34+ viability and stability over 6 h. Moreover, Lovo efficiency seemed to be independent of the number of thawed bags processed and washing solution used in the authors' study. CD3+ cell recovery met the authors' internal specifications (cell recovery >50%), with similar results seen when processing with either the COBE 2991 or Lovo. Additionally, on average, 97% of DMSO was removed after washing with Lovo, minimizing the risk of ARs. The storage conditions post-processing indicated preferred storage conditions of 7 ± 3°C. Finally, if processing time seemed shorter using COBE 2991 for one bag washed, the Lovo device required only one staff member regardless of the number of HPC bags processed.

CONCLUSIONS

The Lovo device seems to provide an opportunity to standardize HPC processing, ensuring patient safety, with, on average, 97% of DMSO removed, while improving recovery of cells of interest and maintaining viability over time in case of delayed transplant. The Lovo device consequently seems to be a serious alternative to the COBE 2991.

[Establishment of Hematopoietic cell transplantation program in developing countries : Guidelines from the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC)]

Hematopoietic cell transplantation (HCT) is the curative treatment for many malignant and non-malignant blood disorders and some solid cancers. However, transplant procedures are considered tertiary level care requiring a high degree of technicality and expertise and generating very high costs for hospital structures in developing countries as well as for patients without health insurance. During the 11th annual harmonization workshops of the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC), a designated working group reviewed the literature in order to elaborate unified guidelines, for developing the transplant activity in emerging countries. Access to infrastructure must comply with international standards and therefore requires a hospital system already in place, capable of accommodating and supporting the HCT activity. In addition, the commitment of the state and the establishment for the financing of the project seems essential.

[Graft reinjection: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

JACIE (Joint Accreditation Committee ISTC EBMT) regulations and standards impose a quality and safety requirement for graft reinjection by nurses. However, the standards do not provide a step-by-step graft reinjection procedure. Because of high medical team turnover, the opening of new transplant centers, and continual questions from colleagues trying to decipher the JACIE standards, the need for a specific procedure goes without saying. We collected graft reinjection procedures from each SFGM-TC center that participated in our survey, thus creating an inventory of the different steps that make up graft reinjection. In addition to reviewing the main regulatory texts and JACIE standards, we sought advice from medical and cellular therapy experts. We observed that most centers use a mix of practices and some unjustified practices. In some transplant units, it is still standard practice to defrost cell therapy products in the transplant unit. Caregivers are aware of the need for a rigorous application of the regulatory requirements and are willing to administer a procedure that provides specific steps for each stage of the process. In this workshop, we questioned each stage of the graft reinjection procedure, which helped us define clear methods of implementation. In the form of a checklist, we offer bone marrow and stem cell transplant units a step-by-step procedure.

[Preservation/congelation of hematopoietic stem cell grafts in a pediatric context: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 7th allogeneic hematopoietic stem cell transplantation clinical practices harmonization workshop series in September 2016 in Lille, France. The objective of our workshop is to provide a discussion on the conservation and congelation of hematopoietic stem cells in a pediatric setting as well as our recommendations for this technique.