Ruxolitinib-induced reactivation of cytomegalovirus and Epstein-Barr virus in graft-versus-host disease.

OBJECTIVES: Steroid-refractory graft-versus-host disease (SR-GVHD) is a challenging complication of allogeneic hematopoietic stem cell transplantation, and leads to high morbidity and mortality rates. The orally administered, selective Janus-associated kinase 1/2 inhibitor ruxolitinib gives overall response rates (ORR) of more than 70 % in acute and chronic SR-GVHD. However, several studies have highlighted an elevated risk of cytomegalovirus (CMV) reactivation in patients with ruxolitinib-treated SR-GVHD. METHODS: We therefore analyzed risk of CMV and Epstein-Barr virus (EBV) primary infection or reactivation in 57 patients with ruxolitinib-treated GVHD, while taking account of the competing risk (CR) of death prior to the first reactivation. RESULTS: Initiation of ruxolitinib treatment was a significant adverse prognostic factor for the CR of first CMV reactivation (hazard ratio (HR)= 1.747, 95 % confidence interval (CI): 1.33-2.92, p < 0.0001) and first EBV reactivation (HR=2.657, 95 % CI: 1.82-3.87, p < 0.0001) during GVHD. In our cohort of ruxolitinib-treated patients, the ORR (48 % and 58 % for acute and chronic GVHD, respectively) and the toxicity profile (haematological adverse events in 29.8 % of the patients) were similar to the literature values. CONCLUSION: Given ruxolitinib's efficacy in SR-GVHD, use of this drug should not be limited by the fear of viral reactivation; however, our present results emphasize the importance of monitoring the viral load.

[How to deal with an unexpected event that could alter the normal activity of cellular therapy? Recommendations of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Comment faire face à un événement inattendu pouvant modifier l'activité normale de thérapie cellulaire ? Recommandations de la Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC).

The SARS-CoV-2 (COVID-19) pandemic has rapidly impacted cell therapy activities across the globe. Not only was this, unexpected event, a threat to patients who had previously received hematopoietic cell transplantation or other cell therapy such as CAR-T cells, but also, it was responsible for a disruption of cell therapy activities due to the danger of the virus and to the lack of solid scientific data on the management of patients and donors. The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) devoted a workshop to issue useful recommendations in such an unexpected event in order to harmonize the actions of all the actors involved in cellular therapy programs so that we can collectively face, in the future, the challenges that could threaten our patients. This work is not specifically dedicated to the SARS-CoV-2 outbreak, but the latter has been used as a concrete example of an unexpected event to build up our recommendations.

[Quality assessment of CAR T-cell activity: Recommendations of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Mutualisation des outils de qualité pour les cellules CAR-T : recommandations de la Société francophone de greffe de moelle et thérapie cellulaire (SFGM-TC).

CAR T-cells are anti-cancer immunocellular therapy drugs that involve reprogramming the patient's T-cells using a transgene encoding a chimeric antigen receptor (CAR). Although CAR T-cells are cellular therapies, the organization for manufacturing and delivering these medicinal products is in many ways different from the one for hematopoietic cell grafts or donor lymphocyte infusions. The implementation of this innovative therapy is recent and requires close coordination between clinical teams, the therapeutic apheresis unit, the cell therapy unit, the pharmaceutical laboratory, and pharmacy. Apart from the regulatory texts, which are regularly modified, and the specific requirements of each pharmaceutical laboratory, there is currently no guide to help the centers initiating their activity and there is no specific indicator to assess the quality of the CAR T-cell activity in each center. The purpose of the current harmonization workshop is to clarify the regulatory prerequisites warranted for a center to have a CAR T-cell activity and to propose recommendations for implementing quality tools, in particular indicators, and allowing their sharing.

Cryopreservation and thawing of hematopoietic stem cell CD34-induced apoptosis through caspase pathway activation: Key role of granulocytes.

INTRODUCTION: Cell damage inescapably occurs during both the freezing and the thawing graft processes for autologous hematopoietic stem cell (HSC) transplantation. To estimate HSC injury, a quality control is performed including: (i) CD34+ quantification; (ii) percentage of CD34+ viability and (iii) evaluation of HSC functional ability to form colony forming unit-granulocyte macrophage (CFU-GM). Apoptosis involves complex pathways such as caspase enzymes. Here, we assess the extent of apoptosis that is caspase-dependent before and after cryoconservation of CD34+, using a Fluorescent Labeled Inhibitor of CAspases (FLICA). METHODS: Caspase pathway activation status was evaluated in 46 patients (multiple myeloma [n = 24], lymphoma [n = 22]), by flow cytometry, using a 7-aminoactinomycin-D (7AAD)/FLICA staining test, in CD34+, CD3+, CD14+ and CD56+ cells. Viable 7AAD-/FLICA+ cells were then correlated with various parameters. RESULTS: We showed a significant caspase pathway activation, with 23% CD34+/7AAD-/FLICA+ cells after thawing, compared with the 2% described in fresh CD34+ cells (P < 0.0001). Moreover, caspase pathway was significantly activated in thawing CD3+, CD56+ and CD14+ cells. We also report a significant correlation between the rate of CD34+/7AAD-/FLICA+ cells and post-thawing granulocytes count (P = 0.042) and their potential to be differentiated into CFU-GM (P = 0.004). DISCUSSION: Our results show substantial cell death, induced by the increase of caspase pathway activation, secondary to the thawing process, and across all study cell types. This observation may affect the immune response quality during recipient aplasia, without detecting a clinical impact. Moreover, caspase pathway activation through CD3+ and CD56+ subpopulations could modify the therapeutic result of donor lymphocytes infusion (DLI).

[Donor Lymphocyte Infusions (DLI): Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Injections de lymphocytes du donneur (DLI) : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

Donor lymphocyte infusion (DLI) can be proposed to treat or prevent the relapse of malignant hemopathies following allogeneic stem cell transplantation. The efficiency has been mainly reported in the treatment of CML and low-grade lymphomas while the anti-tumoral activity is less in forms of acute leukemia and myelodysplastic syndromes. The GVL benefit should always be compared to the possible toxic effects of GVHD. This article updates the initial SFGM-TC recommendations, proposed in 2013, that were focused on the use of DLI. Doses of DLI in the context of haplo-identical stem cell transplantation are now indicated. We confirm that remaining mobilized stem cells may be used as classical DLI. The definition and the place of preemptive and prophylactic DLI are precisely given. Recommendations regarding the quality of thawed DLI as well as necessary clinical and biological follow-up are also described in detail.

[Modalities for preparation, cryopreservation, thawing of hematopoietic stem cells and precautions for infusion to patient: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / 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).

To date, despite an existing regulatory framework and standards, there are no true technical recommendations. A survey of 23 cell processing facilities (France, Belgium and Switzerland) has allowed to overview current practices according to cellular products specifications upon arrival at the facility, with modalities for their preparation prior to cryopreservation, storage, thawing and finally for infusion to patient. Data analysis shows great variability of collected volumes and cell concentrations in cellular products. Despite homogeneous practices for handling cells at the facility, methods vary between centers, especially for the choice of cryoprotective solutions and thawing methods. During the workshop, practices have been discussed and summarized to write of recommendations about the following topics: processing and cryopreservation, thawing, bedside precautions (for infusion). This work identifies some improvements in terms of collection, choice of wash solution of thawed cells and validation of the conditions of carriage.

Characterization of distinct mesenchymal-like cell populations from human skeletal muscle in situ and in vitro.

Human skeletal muscle is an essential source of various cellular progenitors with potential therapeutic perspectives. We first used extracellular markers to identify in situ the main cell types located in a satellite position or in the endomysium of the skeletal muscle. Immunohistology revealed labeling of cells by markers of mesenchymal (CD13, CD29, CD44, CD47, CD49, CD62, CD73, CD90, CD105, CD146, and CD15 in this study), myogenic (CD56), angiogenic (CD31, CD34, CD106, CD146), hematopoietic (CD10, CD15, CD34) lineages. We then analysed cell phenotypes and fates in short- and long-term cultures of dissociated muscle biopsies in a proliferation medium favouring the expansion of myogenic cells. While CD56(+) cells grew rapidly, a population of CD15(+) cells emerged, partly from CD56(+) cells, and became individualized. Both populations expressed mesenchymal markers similar to that harboured by human bone marrow-derived mesenchymal stem cells. In differentiation media, both CD56(+) and CD15(+) cells shared osteogenic and chondrogenic abilities, while CD56(+) cells presented a myogenic capacity and CD15(+) cells presented an adipogenic capacity. An important proportion of cells expressed the CD34 antigen in situ and immediately after muscle dissociation. However, CD34 antigen did not persist in culture and this initial population gave rise to adipogenic cells. These results underline the diversity of human muscle cells, and the shared or restricted commitment abilities of the main lineages under defined conditions.

Association of bone marrow natural killer cell dose with neutrophil recovery and chronic graft-versus-host disease after HLA identical sibling bone marrow transplants.

Allogeneic bone marrow (BM) transplant (BMT) outcomes have been correlated with the infused nucleated, CD34(+), and T- cell dose. The potential impact of natural killer (NK) BM infused cell dose has however not been established. We analysed the outcomes of 78 patients receiving an HLA identical BMT. A higher NK cell dose was associated with the speed of neutrophil (P = 0.05) and platelet recovery (P = 0.04). Higher nucleated cells, CD34(+), CD3(+), CD3(+)/4(+), CD3(+)/8(+) and NK cell dose were associated with a lower incidence of chronic GvHD (cGvHD) in univariate analysis. In multivariate analysis, the risk of cGvHD was increased by a lower NK cell dose [hazard ratio (HR) = 2.3 (1.2-4.4) for cell dose <0.9 x 10(6)/kg; P = 0.01] and an older age [HR = 1.4 /10 years (1.1-1.8); P = 0.002]. In addition, a higher CD3(+)/4(+) and NK cell dose were associated with a decreased incidence of viral infections (P = 0.03 and P = 0.06 respectively). No specific cell subpopulation infused dose was associated with survival. In conclusion, a higher BM NK cell dose is associated with an increased speed of neutrophil recovery and a decreased incidence of cGvHD.

Ex vivo generation of mature and functional human smooth muscle cells differentiated from skeletal myoblasts.

We described the ex vivo production of mature and functional human smooth muscle cells (SMCs) derived from skeletal myoblasts. Initially, myoblasts expressed all myogenic cell-related markers such as Myf5, MyoD and Myogenin and differentiate into myotubes. After culture in a medium containing vascular endothelial growth factor (VEGF), these cells were shown to have adopted a differentiated SMC identity as demonstrated by alphaSMA, SM22alpha, calponin and smooth muscle-myosin heavy chain expression. Moreover, the cells cultured in the presence of VEGF did not express MyoD anymore and were unable to fuse in multinucleated myotubes. We demonstrated that myoblasts-derived SMCs (MDSMCs) interacted with endothelial cells to form, in vitro, a capillary-like network in three-dimensional collagen culture and, in vivo, a functional vascular structure in a Matrigel implant in nonobese diabetic-severe combined immunodeficient mice. Based on the easily available tissue source and their differentiation into functional SMCs, these data argue that skeletal myoblasts might represent an important tool for SMCs-based cell therapy.

ABO-mismatched marrow processing for transplantation: results of 114 procedures and analysis of immediate adverse events and hematopoietic recovery.

BACKGROUND: Red cell (RBC) depletion is needed to bypass ABO mismatch in allogeneic bone marrow transplantation (BMT). Technical and clinical data obtained after bone marrow (BM) processing with a continuous-flow cell separator (Cobe Spectra, Gambro BCT) are reported. STUDY DESIGN AND METHODS: RBC depletion and recovery of nucleated cells, CD3+ cells, CD34+ cells, and colony-forming unit-granulocyte-macrophage were calculated. Bacteriologic contaminations, side effects of graft infusion, and hematopoietic recovery were analyzed. RESULTS: A total of 114 BM samples were processed. The mean volume collected was 1099 mL (range, 390-2450 mL). Initial and residual mean RBCs volumes were 309.9 and 4.0 mL corresponding to a depletion of 98.6 +/- 0.78 percent. Before processing, the mean numbers of nucleated cells, granulocytes, CD3+ cells, CD34+ cells, and CFU-GM were 20.28 x 10(9), 12.79 x 10(9), 1.96 x 10(9), 356.7 x 10(6), and 195.6 x 10(5), respectively. The mean corresponding recoveries after processing were 33.66, 48.98, 82.02, 82.2, and 93.9 percent. Limited side effects were observed in 14 patients without correlation with residual RBCs volume. All but two patients engrafted. CONCLUSION: BM processing with the Cobe Spectra cell separator provides high rates of RBC depletion without significant side effects after BMT.