[Cellular immunotherapy at the University Hospital of Liege : advances, challenges and prospects]. / Immunothérapie cellulaire au CHU de Liège : avancées, défis et perspectives.

Cellular immunotherapy consists in using the cells of the immune system as a therapeutic weapon. In this constantly evolving field, the therapeutic strategies developed at the University Hospital of Liege are hematopoietic stem cell transplantation, mesenchymal stromal cells and targeted therapy with CAR-T cells (Chimeric Antigen Receptor T cells). The first two modalities represent a form of non-targeted cell therapy that has been developed over the past decades. While hematopoietic stem cell transplantation is established as the reference treatment for many hematological diseases, mesenchymal stromal cells are still under investigation in various pathologies (notably Crohn's disease, organ transplantation, COVID-19 and pulmonary fibrosis). By contrast, CAR-T cells represent a recently developed and extremely promising targeted immunotherapy. This therapeutic approach has already revolutionized the treatment of B-cell lymphopathies, and has the potential to do the same for many other diseases in the near future.

L'immunothérapie cellulaire consiste en l'utilisation de cellules du système immunitaire comme arme thérapeutique. Dans ce domaine en évolution constante, les stratégies thérapeutiques développées au CHU de Liège sont la greffe de cellules souches hématopoïétiques, les cellules stromales mésenchymateuses et la thérapie ciblée par cellules CAR-T («Chimeric Antigen Receptor T cells¼). Les deux premières approches représentent une forme de thérapie cellulaire non ciblée, développées depuis de nombreuses années. Si la greffe de cellules souches hématopoïétiques est établie comme le traitement de référence de nombreuses hémopathies, les cellules stromales mésenchymateuses sont, quant à elles, toujours à l'étude dans diverses pathologies (notamment maladie de Crohn, transplantation d'organes, COVID-19 et fibrose pulmonaire). À l'opposé, les cellules CAR-T représentent une immunothérapie ciblée, développée récemment et extrêmement prometteuse. Cette modalité thérapeutique a déjà révolutionné le traitement des lymphopathies B, et elle possède le potentiel d'en faire de même pour de nombreuses autres pathologies dans un avenir proche.

[Influence of obstetric factors on characteristics of umbilical cord blood transplants]. / Influence de facteurs obstétricaux sur les caractéristiques des greffons de sang de cordon ombilical.

OBJECTIVES: There is a correlation between the success of the cord blood transplant and the numbers of HSC found in the unit of cord blood donation. The purpose of this analysis is to identify obstetric factors that may influence the quality of a cord blood unit taken during delivery. METHODS: A retrospective study was carried out at the Liège cord blood bank on a sample of 7.463 cord blood units collected between 2000 and 2016. Eight obstetric factors were analyzed in relation to two dependent variables; the total nucleated cells (TNC) and the volume of one unit of cord blood. The Welch test, the percentiles 25 and 75 and the non-parametric Mann-Whitney Wilcoxon test were used. RESULTS: Several obstetric parameters were found to influence (P<0.05) the quality of the cord blood unit are: cord clamping (>15 seconds), the use of oxytocin during labor, a more advanced gestational age (38-41 weeks), a higher birth weight (>3300 gr), and a higher weight of the placenta (>500 gr). A female newborn and the use of epidural, influence (P<0.05) the number of TNC but not the volume of the cord blood unit. CONCLUSION: We can conclude that the birth weight, the weight of the placenta, the gestational age and cord clamping are parameters that could be used by maternity hospitals to identify births that enable more voluminous grafts which are richer in total nucleated cells.

Review article: mesenchymal stromal cell therapy for inflammatory bowel diseases.

BACKGROUND: Inflammatory bowel diseases (IBD) are chronic relapsing diseases in which pro-inflammatory immune cells and cytokines induce intestinal tissue damage and disability. Mesenchymal stromal cells (MSCs) exert powerful immunomodulatory effects and stimulate tissue repair. AIM: To review the current data on mesenchymal stromal cell therapy in IBD. METHOD: We searched PubMed and 'ClinicalTrials.gov' databases using the terms 'mesenchymal stromal cells', 'mesenchymal stem cell transplantation', 'inflammatory bowel diseases', 'Crohn disease' and 'colitis, ulcerative'. Additional publications were identified from individual article reference lists. RESULTS: MSCs include inhibition of Th1/Th17 lymphocytes and recruitment of regulatory T lymphocytes, induction of antigen-presenting cells into a regulatory-like profile, and stimulation of epithelial cell differentiation and proliferation. More than 200 patients with refractory fistulas have been treated with local injections of MSCs, resulting in complete response in more than half, and in overall response in approximately two thirds of patients. In refractory luminal Crohn's disease, 49 cases of systemic MSC infusions have been reported, while trials with autologous MSCs resulted in mitigated responses, studies using allogeneic MSCs were promising, with around 60% of patients experiencing a response and around 40% achieving clinical remission. CONCLUSIONS: Mesenchymal stromal cells might represent a promising therapy for IBD, especially for Crohn's disease. There remain many unsolved questions concerning the optimal origin and source of mesenchymal stromal cells, dosage and modalities of administration. Moreover, mesenchymal stromal cells still need to prove their effectiveness compared with conventional treatments in randomised controlled trials.

[Conservation and destruction of autologous and allogeneic cryopreserved cellular products: recommendations from the SFGM-TC]. / Modalités de conservation et de destruction des produits cellulaires cryopréservés : recommandations de la SFGM-TC.

Thousands of autologous and at less extent allogeneic hematopoietic stem cells (HSC) bags are cryopreserved in France. The majority of autologous HSC grafts are used within a year after collection. However, many bags are still unused and cryopreserved for many years. In France and on a European scale, the ever-growing number of cryopreserved bags represents a real economic health concern. Indeed, the cost of storage is about 100€ per bag and per year. In addition, quality and therapeutic value of these long-term cryopreserved grafts needs to be evaluated. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from its member centers across France. These workshops took place in September 2013 in Lille. In this article, we addressed the issue of the destruction of long-term cryopreserved grafts be them autologous or allogeneic and provide recommendations regarding their destruction.

Quality controls on cord blood unit contiguous segments: recommendation of the SFGM-TC.

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. Literature and intra-laboratories studies suggest that attached segment is representative of cord blood unit (CBU). Nevertheless, some discrepancies have been observed when analyzing large data registries. To address these issues, we have listed recommendations to increase the standardization of segment processing and quality control (QC), information on units of measurement and specifications and action to be taken in case of out of specifications QC results on segment.

[Mesenchymal stromal cells and organ transplantation]. / Cellules stromales mésenchymateuses et transplantation d'organes.

Mesenchymal stromal cells (MSC) are multipotent and self-renewing cells. MSC are studied for their in vivo and in vitro immunomodulatory effects, in the prevention or the treatment of isehemic injury, and for their potential properties of tissue or organ reconstruction. Over the last few years, the potential role of MSC in organ transplantation has been studied both in vitro and in vivo, and their properties make them an ideal potential cell therapy after solid organ transplantation. A prospective, controlled, phase 1-2 study has been initiated at the CHU of Liege, Belgium. This study assesses the potential risks and benefits of MSC infusion after liver or kidney transplantation. Even if the preliminary results of this study look promising, solely a prospective, randomized, large scale, phase 3 study will allow the clinical confirmation of the theoretical benefits of MSC in solid organ transplantation.

Cleanrooms and tissue banking how happy I could be with either GMP or GTP?

The regulatory framework of tissue banking introduces a number of requirements for monitoring cleanrooms for processing tissue or cell grafts. Although a number of requirements were clearly defined, some requirements are open for interpretation. This study aims to contribute to the interpretation of GMP or GTP guidelines for tissue banking. Based on the experience of the participating centers, the results of the monitoring program were evaluated to determine the feasibility of a cleanroom in tissue banking and the monitoring program. Also the microbial efficacy of a laminar airflow cabinet and an incubator in a cleanroom environment was evaluated. This study indicated that a monitoring program of a cleanroom at rest in combination with (final) product testing is a feasible approach. Although no statistical significance (0.90 < p < 0.95) was found there is a strong indication that a Grade D environment is not the ideal background environment for a Grade A obtained through a laminar airflow cabinet. The microbial contamination of an incubator in a cleanroom is limited but requires closed containers for tissue and cell products.

Low T-cell chimerism is not followed by graft rejection after nonmyeloablative stem cell transplantation (NMSCT) with CD34-selected PBSC.

We investigate the feasibility of CD34-selected peripheral blood stem cell (PBSC) transplantation followed by pre-emptive CD8-depleted donor lymphocyte infusions (DLI) after a minimal conditioning regimen. Six patients with advanced hematological malignancies ineligible for a conventional myeloablative transplant (n=5) or metastatic renal cell carcinoma (n=1), and with an HLA-identical (n=4) or alternative (n=2) donor were included. The nonmyeloablative conditioning regimen consisted in 2 Gy TBI alone (n=4), 2 Gy TBI and fludarabine (RCC patient, n=1) or cyclophosphamide and fludarabine (patient who had previously received 12 Gy TBI, n=1). Post transplant immunosuppression was carried out with cyclosporin (CyA) and mycophenolate mofetil (MMF). Initial engraftment was achieved in all patients. One out of six patients (17%) experienced grade > or =2 acute GVHD only after abrupt cyclosporin discontinuation and alpha interferon therapy for life-threatening tumor progression. T-cell chimerism was 23% (19-30) on day 28, 32% (10-35) on day 100, 78% (49-95) on day 180 and 99.5% (99-100) on day 365. Three out of four patients who had measurable disease before the transplant experienced a complete response. We conclude that CD34-selected NMSCT followed by CD8-depleted DLI is feasible and preserves engraftment and apparently also the graft-versus-leukemia (GVL) effect. Further studies are needed to confirm this encouraging preliminary report.

Administration of erythopoietin and granulocyte colony-stimulating factor in donor/recipient pairs to collect peripheral blood progenitor cells (PBPC) and red blood cell units for use in the recipient after allogeneic PBPC transplantation.

BACKGROUND AND OBJECTIVES: It may be useful to reduce the exposure of transplant recipients to homologous blood. This may be achieved by procuring donor-derived red blood cell (RBC) units, collecting more peripheral blood progenitor cells (PBPC) with a combination of granulocyte colony-stimulating factor (G-CSF) + recombinant human erythropoietin (rHuEpo) and by administering rHuEpo post-transplantation. DESIGN AND METHODS: Eight ABO-compatible donors were treated with rHuEpo and intravenous iron to collect 12 RBC units for use in their recipients. PBPC were collected after mobilization with rHuEpo and G-CSF in the same donors. The recipients received G-CSF and rHuEpo post-transplantation. A control group of 10 donor/recipient pairs received G-CSF alone for PBPC mobilization and after the transplantation. RESULTS: Eighty-six out of 91 planned RBC units were collected in the donors without significant decrease in hematocrit because of a 4-fold increase in RBC production despite functional iron deficiency. After 2 leukaphereses, the cumulative yields of NC and CFU-GM were lower in the study group while those of BFU-E, CFU-Mix and CD34+ cells were similar. However, erythroid recovery was significantly accelerated in the study group. INTERPRETATION AND CONCLUSIONS: Collection of 12 RBC units within 6 weeks is feasible with rHuEpo and intravenous iron; this strategy allows a dramatic reduction in recipient exposure to homologous blood; rHuEpo has no synergistic effect with G-CSF for mobilization of PBPC in normal donors and may even be deleterious; and rHuEpo in the recipient may enhance erythroid engraftment.

[The Hemovigilance Commission of the University Hospital Center]. / La commission d'hémovigilance du CHU.

As suggested by the National Blood Council, a Hemovigilance Committee was set up in the University Hospital of Liège in 1995. A multidisciplinary discussion takes place on any action aiming at the improvement of transfusion safety, and the follow-up of its implementation. The first issue to be discussed was the set up of a detailed documentation of all blood transfusions. The data are now recorded on a single document allowing proper identification of people and products involved, and of the eventual incidents. This document has lead to a better transfusion safety and to an improved administrative management of blood transfusion. The Commission has been coordinating two multi-centric studies analyzing the consumption of fresh blood products and the incidence of transfusion reactions. Among blood-saving policies, autologous transfusion and volume reduction of samples drawn for laboratory purposes have been discussed. Other measures were taken to improve the labeling of samples for cross-mach and to actively follow-up transfusion reactions. By its actions and advises, the Commission aims to direct strategies towards a safe and rational use of blood products.

Successful mobilization of peripheral blood HPCs with G-CSF alone in patients failing to achieve sufficient numbers of CD34+ cells and/or CFU-GM with chemotherapy and G-CSF.

BACKGROUND: Mobilization with chemotherapy and G-CSF may result in poor peripheral blood HPC collection, yielding <2 x 10(6) CD34+ cells per kg or <10 x 10(4) CFU-GM per kg in leukapheresis procedures. The best mobilization strategy for oncology patients remains unclear. STUDY DESIGN AND METHODS: In 27 patients who met either the CD34 (n = 3) or CFU-GM (n = 2) criteria or both (n = 22), the results obtained with two successive strategies-that is, chemotherapy and G-CSF at 10 microg per kg (Group 1, n = 7) and G-CSF at 10 microg per kg alone (Group 2, n = 20) used for a second mobilization course-were retrospectively analyzed. The patients had non-Hodgkin's lymphoma (5), Hodgkin's disease (3), multiple myeloma (5), chronic myeloid leukemia (1), acute myeloid leukemia (1), breast cancer (6), or other solid tumors (6). Previous therapy consisted of 10 (1-31) cycles of chemotherapy with additional chlorambucil (n = 3), interferon (n = 3), and radiotherapy (n = 7). RESULTS: The second collection was undertaken a median of 35 days after the first one. In Group 1, the results of the two mobilizations were identical. In Group 2, the number of CD34+ cells per kg per apheresis (0.17 [0.02-0.45] vs. 0.44 [0.11-0.45], p = 0. 00002), as well as the number of CFU-GM (0.88 [0.00-13.37] vs. 4.19 [0.96-21.61], p = 0.00003), BFU-E (0.83 [0.00-12.72] vs. 8.81 [1. 38-32.51], p = 0.00001), and CFU-MIX (0.10 [0.00-1.70] vs. 0.56 [0. 00-2.64], p = 0.001134) were significantly higher in the second peripheral blood HPC collection. However, yields per apheresis during the second collection did not significantly differ in the two groups. Six patients in Group 1 and 18 in Group 2 underwent transplantation, and all but one achieved engraftment, with a median of 15 versus 12 days to 1,000 neutrophils (NS), 22 versus 16 days to 1 percent reticulocytes (NS), and 26 versus 26 days to 20,000 platelets (NS), respectively. However, platelet engraftment was particularly delayed in many patients. CONCLUSION: G-CSF at 10 microg per kg alone may constitute a valid alternative to chemotherapy and G-CSF to obtain adequate numbers of peripheral blood HPCs in patients who previously failed to achieve mobilization with chemotherapy and G-CSF. This strategy should be tested in prospective randomized trials.

Delayed massive immune hemolysis mediated by minor ABO incompatibility after allogeneic peripheral blood progenitor cell transplantation.

BACKGROUND: Bone marrow transplantation with minor ABO incompatibility may be followed by moderate delayed hemolysis of the recipient's red cells by donor-derived ABO antibodies. This reaction may be more severe after transplantation of peripheral blood progenitor cells (PBPCs). CASE REPORT: A 16-year-old boy underwent an allogeneic PBPC transplant from his HLA-mismatched mother as treatment for acute myeloblastic leukemia that had proved resistant to induction chemotherapy. Transfusion of the unmanipulated PBPCs proceeded without any complication, despite the difference in ABO blood group (donor, O Rh-positive; recipient, A Rh-positive). On Day 7, a rapid drop in hemoglobin to 4 g per dL was observed, which was attributed to a massive hemolysis. All the recipient's group A red cells were destroyed within 36 hours. This delayed and rapidly progressive hemolytic anemia was not associated with the transfusion of the donor's plasma. Rather, the anti-A titer increased in parallel with marrow recovery, which suggested an active synthesis of these antibodies by immunocompetent cells from the donor against the recipient's red cells. The mother's anti-A titer was retrospectively found to be 2048. Her unusually high titer is probably due to prior sensitization during pregnancies. On Day 12, the patient developed grade IV graft-versus-host disease, which proved resistant to all treatments instituted and led to his death on Day 35. CONCLUSION: PBPC transplantation with minor ABO incompatibility may be associated with significant risk of massive delayed hemolysis.

Peripheral blood progenitor cell collections in cancer patients: analysis of factors affecting the yields.

BACKGROUND AND OBJECTIVE: Peripheral blood progenitor cells (PBPC) are now widely used to restore hematopoiesis following high dose chemotherapy in patients with malignancies. We sought to identify parameters that could predict the yield of PBPC after mobilization with chemotherapy (CT) with or without granulocyte colony-stimulating factor (G-CSF) in cancer patients. DESIGN AND METHODS: One hundred and fifty patients underwent 627 PBPC collections during the recovery phase following CT with (n = 469) or without (n = 142) G-CSF. Hemogram, CFC-assays and CD34+ cell count were performed on peripheral blood and leukaphereses products. After log transformation of the data, differences between groups were assessed with the unpaired t-test or one-way analysis of variance. RESULTS: Seventeen and two patients required 2 and 3 mobilization cycles respectively to reach our target of 15x10(4) CFU-GM/kg. In patients with lymphoma but not in those with leukemia, the yields of both CFU-GM and CD34+ cells/kg were dramatically increased when G-CSF was added to CT for mobilization. In collections primed with CT and G-CSF, better yields were obtained in patients with breast cancer or small-cell lung carcinoma (SCLC) as opposed to other solid tumors and leukemia. Among potential predictive factors of CT- and G-CSF-primed harvests, we found that the CD34+ cell count in peripheral blood (PB) was strongly correlated with both the CFU-GM and CD34+ cell yields. Except in leukemia patients, more than 1x10(6) CD34+ cells/kg were harvested when the CD34+ cell count in blood was above 20x10(6)/L. Similarly, better results were obtained in collections performed when the percentage of myeloid progenitors in blood on the day of apheresis was above 5 % or when the leukocyte count in blood was above 5x10(9)/L. INTERPRETATION AND CONCLUSIONS: A diagnosis of breast cancer or SCLC, a leukocyte count in PB of more than 5x10(9)/L, more than 5% myeloid progenitors or more than 20x10(6) CD34+ cells/L in PB were associated with higher yields of PBPC in collections mobilized with CT+G-CSF.

Hemovigilance: clinical tolerance of solvent-detergent treated plasma.

OBJECTIVE: This study was conducted to assess retrospectively the clinical tolerance of SD treated plasma and to compare it to other labile blood products (red blood cell and platelet concentrates). METHODS: Adverse events (AEs) related to the use of blood products at the Blood Transfusion Center (BTC) are routinely collected through a formalised system of hemovigilance. All AEs reported are entered into a safety data base which was used for the study. All AEs reported during a one-year period to the BTC were retrospectively re-assessed and descriptive statistics calculated. RESULTS: 5064 units of SD treated plasma were transfused to 894 recipients during the study period at the occasion of 1553 transfusions. No AE associated to SD treatment plasma was reported during that period. In contrast, during the same period, 485 AEs associated with the use of red blood cell concentrates (RBCC) were reported in 251 patients at the occasion of 262 transfusions. 2.1% (251/11,748) of the patients transfused with RBCC experienced one or more AEs. The incidence of AEs per unit transfused was 1.3% (485/37,332), and 2.4% (485/20,460) of RBCC transfusions were associated with one or more AEs. 142 AEs associated with the use of platelet concentrate (PC) were observed in 69 patients at the occasion of 73 transfusions. 4.2% (69/1645) of patients transfused with PC experienced one or more AEs. The incidence of AEs per unit transfused was 1.1% (142/12,772), and 2.8% (142/5034) of PC transfusions were associated with one or more AEs. All reported AEs were classified and non serious. The most frequently observed AEs were fever, chills and rashes which accounted for roughly 64% of all reported AEs. CONCLUSION: As for the overall clinical tolerance of red cell and platelet concentrates, the results of this study are in complete agreement with the published literature. The study also confirms the extremely good tolerability of SD treated plasma in comparison with other labile blood products.

Circadian and seasonal variations of hematopoiesis in cord blood.

Cord blood hematopoietic progenitors undergo circadian and seasonal variations. The lowest values are obtained between 4:00 and 12:00, as well as between May and August. This represents the first observation of such rhythms before birth.

Hematopoietic recovery in cancer patients after transplantation of autologous peripheral blood CD34+ cells or unmanipulated peripheral blood stem and progenitor cells.

BACKGROUND: A study of CD34+ cell selection and transplantation was carried out with particular emphasis on characteristics of short- and long-term hematopoietic recovery. STUDY DESIGN AND METHODS: Peripheral blood stem and progenitor cells (PBPCs) were collected from 32 patients, and 17 CD34+ cell-selection procedures were carried out in 15 of the 32. One patient in whom two procedures failed to provide 1 x 10(6) CD34+ cells per kg was excluded from further analysis. After conditioning, patients received CD34+ cells (n = 10, CD34 group) or unmanipulated (n = 17, PBPC group) PBPCs containing equivalent amounts of CD34+ cells or progenitors. RESULTS: The yield of CD34+ cells was 53 percent (18-100) with a purity of 63 percent (49-82). The CD34+ fraction contained 66 percent of colony-forming units--granulocyte-macrophage (CFU-GM) and 58 percent of CFU of mixed lineages, but only 33 percent of burst-forming units-erythroid (BFU-E) (p < 0.05). Early recovery of neutrophils and reticulocytes was identical in the two groups, although a slight delay in platelet recovery may be seen with CD34+ cell selection. Late hematopoietic reconstitution, up to 1.5 years after transplant, was also similar. The two groups were thus combined for analyses of dose effects. A dose of 40 x 10(4) CFU-GM per kg ensured recovery of neutrophils to a level of 1 x 10(9) per L within 11 days, 15 x 10(4) CFU of mixed lineages per kg was associated with platelet independence within 11 days, and 100 x 10(4) BFU-E per kg predicted red cell independence within 13 days. However, a continuous effect of cell dose well beyond these thresholds was apparent, at least for neutrophil recovery. CONCLUSION: CD34+ cell selection, despite lower efficiency in collecting BFU-E, provides a suitable graft with hematopoietic capacity comparable to that of unmanipulated PBPCs. In both groups, all patients will eventually show hematopoietic recovery of all three lineages with 1 x 10(6) CD34+ cells per kg or 5 x 10(4) CFU-GM per kg, but a dose of 5 x 10(6) CD34+ cells or 40 x 10(4) CFU-GM per kg is critical to ensure rapid recovery.

Epoetin alfa facilitates presurgical autologous blood donation in non-anaemic patients scheduled for orthopaedic or cardiovascular surgery.

Patients expected to need at least three units of blood for their elective cardiovascular or orthopaedic surgery, were allocated randomly to receive intravenous (i.v.) Epoetin alfa 600 IU kg-1 (n = 27), 300 IU kg-1 (n = 30) or placebo (n = 23), on days 1, 4 and 7. Provided haemoglobin > or = 11 g dL-1, one unit of blood was collected on days 1, 4, 7, 11 and 14. Iron supplementation was given throughout the study. Surgery was scheduled between days 18 and 21. Significantly more patients treated with Epoetin alfa (100% for 600 IU kg-1; 97% for 300 IU kg-1) were able to donate > or = 4 units of blood compared with placebo (78%) (P = 0.011 and P = 0.032). No significant differences were seen in total patient exposure to homologous blood (7.4%, 3.3% and 17.4%, respectively). Mean red cell volume donated (P = 0.005 for 600 IU kg-1; P = 0.158 for 300 IU kg-1 both vs. placebo) and production (P < 0.001 and P = 0.012, respectively) were dose related. Twenty-four patients became iron deficient. No differences in the incidence of adverse events were seen between the groups.