Tarek Ben Othman

Phenotypical and functional characteristics of mesenchymal stem cells from bone marrow: comparison of culture using different media supplemented with human platelet lysate or fetal bovine serum.

IntroductionMesenchymal stem cells (MSCs) are multipotent cells able to differentiate into several mesenchymal lineages, classically derived from bone marrow (BM) but potentially from umbilical cord blood (UCB). Although they are becoming a good tool for regenerative medicine, they usually need to be expanded in fetal bovine serum (FBS)-supplemented media. Human platelet lysate (HPL) has recently been proposed as substitute for safety reasons, but it is not yet clear how this supplement influences the properties of expanded MSCs.MethodsIn the present study, we compared the effect of various media combining autologous HPL with or without FBS on phenotypic, proliferative and functional (differentiation, cytokine secretion profile) characteristics of human BM-derived MSCs.ResultsDespite less expression of adipogenic and osteogenic markers, MSCs cultured in HPL-supplemented media fully differentiated along osteoblastic, adipogenic, chondrogenic and vascular smooth muscle lineages. The analyses of particular specific proteins expressed during osteogenic differentiation (calcium-sensing receptor (CaSR) and parathormone receptor (PTHR)) showed their decrease at D0 before any induction for MSC cultured with HPL mostly at high percentage (10%HPL). The cytokine dosage showed a clear increase of proliferation capacity and interleukin (IL)-6 and IL-8 secretion.ConclusionsThis study shows that MSCs can be expanded in media supplemented with HPL that can totally replace FBS. HPL-supplemented media not only preserves their phenotype as well as their differentiation capacity, but also shortens culture time by increasing their growth rate.

Allogeneic Hematopoietic Stem-Cell Transplantation for Acute Myeloid Leukemia in Remission: Comparison of Intravenous Busulfan Plus Cyclophosphamide (Cy) Versus Total-Body Irradiation Plus Cy As Conditioning Regimen—A Report From the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

PURPOSE Cyclophosphamide (Cy) combined with total-body irradiation (TBI) or with busulfan (Bu) are currently the most common myeloablative regimens used in allogeneic stem-cell transplantation (alloSCT) in adults with acute myelogenous leukemia (AML). Intravenous (IV) Bu has more predictable bioavailability and a safer toxicity profile than the oral formulation. Comparative studies of outcomes have been performed between oral Bu/Cy and Cy/TBI, but there have been no comparative trials in the era of IV Bu. PATIENTS AND METHODS We performed a retrospective registry-based study comparing outcomes of patients with AML in first or second remission after alloSCT from sibling donors who underwent IV Bu/Cy (n = 795) or Cy/TBI (n = 864) conditioning. RESULTS Engraftment rate was 98% and 99% after IV Bu/Cy and Cy/TBI, respectively. Grade 2 to 4 acute graft-versus-host disease (GVHD) was significantly lower in the IV Bu/Cy compared with Cy/TBI group (P < .001). Similarly, chronic GVHD was significantly lower in the IV Bu/Cy compared with Cy/TBI group (P = .003). Cumulative incidence of 2-year nonrelapse mortality (NRM; ± standard deviation [SD]) was 12% ± 1% in the IV Bu/Cy group and 15% ± 2% in the Cy/TBI group (P = .14), and 2-year relapse incidence (RI; ± SD) was 26% ± 3% and 21% ± 1%, respectively (P = .012). Leukemia-free survival (LFS) rate (± SD) was 61% ± 2% after IV Bu/Cy and 64% ± 2% after Cy/TBI (P = .27). In multivariable analysis, adjusting for differences between both groups, patients who received IV Bu/Cy had lower acute and chronic GVHD, higher RI, and a trend toward lower NRM. LFS was not statistically different between the two conditioning regimens. CONCLUSION This retrospective study shows that final outcomes after myeloablative conditioning using IV Bu/Cy were not statistically different from those after Cy/TBI.

Prevention of central venous line-related thrombosis by continuous infusion of low-dose unfractionated heparin, in patients with haemato-oncological disease A randomized controlled trial

We have conducted a prospective randomized controlled trial to evaluate the role of low-dose unfractionated heparin prophylaxis in preventing central venous line-related thrombosis in patients with haemato-oncological disease. Patients were randomly assigned to receive either prophylactic intravenous unfractionated heparin (continuous infusion of 100 IU/kg/daily) or 50 ml/daily of normal saline solution as a continuous infusion. CVLs were externalized, non tunneled, double lumen catheters. All CVLs were placed percutaneously by the same physician in the subclavian vein. Upper limb veins were systematically examined by ultrasonography just before, or <24 hours after, catheter removal, and in case of clinical signs of thrombosis. One hundred and twenty-eight CVLs were inserted. Catheter-related thrombosis occurred in 1.5% of the catheters inserted in patients of the heparin group, and in 12.6% in the control group (p = 0.03). No other risk factors were found for the development of catheter-related thrombosis. Two and three patients experienced severe bleeding in the heparin group, and in the control group, respectively (p = 0.18). There were no other side-effects clearly ascribable to the use of unfractionated heparin. This is the first prospective, randomized study, which shows that low-dose of unfractionated heparin is safe and effective to prevent catheter-related thrombosis in patients with haemato-oncological disease.

Randomized Trial of Prevention of Catheter-Related Bloodstream Infection by Continuous Infusion of Low-Dose Unfractionated Heparin in Patients With Hematologic and Oncologic Disease

PURPOSE Infection is a serious complication of central venous catheters in immunocompromised patients. Catheter-related infection may be caused by fibrin deposition associated with catheters. Interventions designed to decrease fibrin deposition have the potential to reduce catheter-related infections. The purpose of this study was to evaluate the role of low-dose unfractionated heparin in preventing catheter-related bloodstream infection in patients with hemato-oncological disease. PATIENTS AND METHODS This study was a randomized, controlled trial in which patients with nontunneled catheters were randomly assigned to receive either intravenous unfractionated heparin (continuous infusion of 100 U/kg per day) or 50 mL/day of normal saline solution as a continuous infusion (control group). Heparin was continued until the day of discharge. Catheter-related bloodstream infection was defined according to Infectious Disease Society of America guidelines. RESULTS Two hundred and eight patients were randomly assigned. Four patients were excluded after assignment. Ultimately, 204 patients were analyzed. Catheter-related bloodstream infection occurred in 6.8% (7 of 102 catheters) of those in the heparin group (2.5 events per 1,000 days) and in 16.6% (17 of 102 catheters) of those in the control group (6.4 events per 1,000 days) (P = .03). No other risk factors were found for the development of catheter-related bloodstream infection. Four and five patients experienced severe bleeding in the heparin and control groups, respectively (P = .2). We did not observe heparin-induced thrombocytopenia. CONCLUSION The use of continuous infusion of low-dose unfractionated heparin (100 U/kg per day) can be a practical and economical approach to the prevention of catheter-related bloodstream infection in patients with hemato-oncological disease.

Hemophagocytic syndrome after hematopoietic stem cell transplantation: a prospective observational study

The aim of this prospective observational study was to evaluate the incidence of hemophagocytic syndrome (HPS) after hematopoietic stem cell transplantation (HSCT). Between July 2006 and December 2007, all patients who received a HSCT in our institution were included in this study. All the following criteria were needed for the diagnosis of HPS: sustained fever over 7 days; cytopenia (neutropenia and/or thrombocytopenia); presence of more than 3% mature macrophages in bone marrow; hyperferritinaemia (>1,000 ng/mL). During this study, 171 patients received a HSCT (68 allogeneic and 103 autologous). The median age was 32 years (3–62). We observed six cases of HPS (6/68; 8.8%) after allogeneic stem cell transplantation (ASCT): one case of EBV-related HPS, two cases of CMV-related HPS, and three cases with no evidence of bacterial, fungal or viral infections. We observed only one case of CMV-related HPS (1/103; 0.9%) after autologous stem cell transplantation. Four patients died despite aggressive supportive care. To our knowledge, this is the first prospective observational study conducted with the aim to evaluate the incidence of HPS after HSCT. This study provides a relatively high incidence of HPS after ASCT. When sustained fever with progressive cytopenia and hyperferritinaemia are observed, HPS should be suspected, and bone marrow aspirate considered. The rapid diagnosis of HPS and the early initiation of an appropriate treatment are essential for patient management.

Effectiveness of fixed 50% nitrous oxide oxygen mixture and EMLA cream for insertion of central venous catheters in children.

Although the equimolecular mixture of oxygen and nitrous oxide (EMONO) seems a good choice to relieve procedure‐related pain in children, it has not been evaluated for insertion of central venous catheters in children. To assess the safety and the effectiveness of this gas mixture for insertion of central venous catheters, we conducted a prospective observational study.

Hematopoietic stem cell transplantation practice variation among centers in the Eastern Mediterranean Region (EMRO): Eastern Mediterranean Bone Marrow Transplantation (EMBMT) group survey

INTRODUCTION This practice survey is conducted to analyze clinical hematopoietic stem cell transplantation (HSCT) practice variability among centers in the WHO Eastern Mediterranean Region (EMRO), as represented by the Eastern Mediterranean Blood and Marrow Transplantation (EMBMT) group. METHOD This internet based survey was completed by the medical program directors of the EMBMT centers; 17 centers participated. The survey collected data on various clinical aspects of HSCT practice. RESULTS Consistency in pre HSCT cardiac (100%), pulmonary (82%) and viral screen (100%) was observed. Obtaining informed consent was universal. Pre-HSCT psychological assessment is practiced in 50% of the centers. All centers used single-bedded rooms with HEPA filters. Visitor policy during neutropenic phase and the use of gowns, masks or gloves when examining patients varied among centers. MRSA/VRE screen and use of low bacterial diet were applied in 65% and 82%, respectively. Anti-bacterial prophylaxis is employed in 58% (Auto-SCT) and 60% (Allo-SCT) of the centers. Drug choice varied (cotrimoxazole, ciprofloxacin, levofloxacin, piperacillin-tazobactam); 60% of the centers used penicillin prophylaxis in GVHD patients. PCP prophylaxis is applied in 58% (Auto-SCT) and 87% (Allo-SCT) of the centers; cotrimoxazole is usually used. Anti-viral prophylaxis with acyclovir or, less commonly, valacyclovir is used in 70% (Auto-SCT) and 93% (Allo-SCT) of centers. Anti-fungal prophylaxis is applied in 70% (Auto-SCT), 93% (myeloablative Allo-SCT) and 87% (reduced intensity [RIC] Allo-SCT). Fluconazole is used in all Auto-SCT and majority of Allo-SCT recipients; few centers used other agents (itraconazole, voriconazole, amphotericin B) in Allo-SCT. Prophylactic GCSF use varied among centers: Auto-SCT 77%, myeloablative Allo-SCT 33%, RIC Allo-SCT 27%. Use of ursodeoxycholic acid for venoocclusive disease (VOD) prophylaxis is variable: 60% (Allo-SCT) and 12% (Auto-SCT). Cyclosporine/methotrexate is the most commonly used GVHD prophylaxis in myeloablative Allo-SCT (93%); heterogeneity was seen in RIC SCT. Treatment of steroid refractory acute GVHD varied (ATG 53%, higher steroid dose 40%). CMV monitoring varied between antigenemia (53%) and PCR (40%) techniques. Pre-emptive anti CMV therapy is used in 86% of the centers, while 7% used routine CMV prophylaxis; 7% had no specific CMV management policy. CONCLUSION Consistency was observed in areas of pre-SCT work up, use of single rooms, HEPA filters and GVHD prophylaxis. Heterogeneity is observed in other practice aspects including other isolation measures, anti-microbial prophylaxis, VOD prophylaxis, growth factor use and treatment of steroid refractory GVHD. Further studies are needed to probe the impact of such practice variations on post-transplant outcome and to ascertain the best clinical practice approach.

Hematopoietic Stem Cell Transplantation in the Eastern Mediterranean Region (EMRO) 2008-2009: Report on behalf of the Eastern Mediterranean Bone Marrow Transplantation (EMBMT) Group

BACKGROUND The Eastern Mediterranean Bone Marrow Transplantation (EMBMT) Group has accumulated over 25 years of data and experience in hematopoietic stem cell transplantation (HSCT), most particularly in hemoglobinopathies, severe aplastic anemia (SAA), and inherited metabolic and immune disorders, in addition to hematologic malignancies peculiar to the region and where recent updates in trends in activities are warranted. OBJECTIVES To study trends in HSCT activities in the World Health Organization-Eastern Mediterranean (EM) region surveyed by EMBMT between 2008 and 2009. STUDY DESIGN Retrospective analysis of the survey data, mainly of the cumulative number of transplants, types of transplants (autologous vs. allogeneic), types of conditioning as myeloablative (MAC) vs. reduced intensity conditioning (RIC) and trends in leukemias, hemoglobinopathies, SAA, inherited bone marrow failure syndromes amongst others. RESULTS AND DISCUSSION Fourteen teams from ten Eastern Mediterranean Region Organization (EMRO) countries reported their data (100% return rate) to the EMBMT for the years 2008-2009 with a total of 2608 first HSCT (1286 in 2008; 1322 in 2009). Allogeneic HSCT represented the majority (63%) in both years. The main indications for allogeneic HSCT were acute leukemias (732; 44%), bone marrow failure syndromes (331, 20%), hemoglobinopathies (255; 15%) and immune deficiencies (90; 5%). There was a progressive increase in the proportions of chronic myeloid leukemia (CML) cases transplanted beyond the first chronic phase (3; 7% of all CML cases in 2008 vs 13; 29% in 2009). The main indications for autologous transplants were plasma cell disorders (345; 36%) Hodgkin disease (256; 27%), non-Hodgkin lymphoma (207; 22%) and solid tumors (83; 9%). RIC continued to show a progressive increase over the years (7% in 2007, 11% in 2008 and 13% in 2009), yet remained relatively low compared to contemporary practices in Europe published by EBMT. The vast majority (95%) of allo-HSCT sources were from sibling donors with a continued dominance of peripheral blood (PB) (1076; 63%), while cord blood transplant (CBT) increased to 83 (5% of allo-HSCT), matched unrelated donor (MUD) remained underutilized (1; 0%) and there were no haploidentical transplants reported. Large centers with >50 HSCT/year showed a plateau of the total number of allo-HSCT over the last 5 years that may be related to capacity issues and needs further study. CONCLUSIONS AND RECOMMENDATIONS There is an overall increased rate of HSCT in the EMRO region with a significant increase in utilization of CBT and allogeneic PB-HSCT as a valuable source. However, further research on outcome data and development of regional donor banks (CB and MUD) may help facilitate future planning to satisfy the regional needs and increase collaboration within the group and globally.

Trends of Hematopoietic stem cell transplantation in the Eastern Mediterranean region, 1984–2007

Hematopoietic stem cell transplantation (HSCT) activity was surveyed in the 9 countries in the World Health Organization Eastern Mediterranean region that reported transplantation activity. Between the years of 1984 and 2007, 7933 transplantations were performed. The number of HSCTs per year has continued to increase, with a plateau in allogeneic HSCT (allo-HSCT) between 2005 and 2007. Overall, a greater proportion of transplantations were allo-HSCT (n = 5761, 77%) compared with autologous HSCT (ASCT) (n = 2172, 23%). Of 5761 allo-HSCT, acute leukemia constituted the main indication (n = 2124, 37%). There was a significant proportion of allo-HSCT for bone marrow failures (n = 1001, 17%) and hemoglobinopathies (n = 885, 15%). The rate of unrelated donor transplantations remained low, with only 2 matched unrelated donor allo-HSCTs reported. One hundred umbilical cord blood transplantations were reported (0.017% of allo-HSCT). Peripheral blood stem cells were the main source of graft in allo-HSCT, and peripheral blood stem cells increasingly constitute the main source of hematopoietic stem cells overall. Reduced-intensity conditioning was utilized in 5.7% of allografts over the surveyed period. ASCT numbers continue to increase. There has been a shift in the indication for ASCT from acute leukemia to lymphoproliferative disorders (45%), followed by myeloma (26%). The survey reflects transplantation activity according to the unique health settings of this region. Notable differences in transplantation practices as reported to the European Group for Blood and Marrow Transplantation over recent years are highlighted.

Status of hematopoietic stem cell transplantation in the WHO Eastern Mediterranean Region (EMRO).

Several centers are now performing allogeneic hematopoietic stem cell transplantation (HSCT) in the World Health Organization Eastern Mediterranean Region (EMRO) but the availability is still limited due to high cost and the need for multi-disciplinary team and an advanced laboratory support. Special issues including compatible donor availability, potential for alternate donor programs, differences in pattern of disease, pre-HSCT general status particularly for patients with BM failure, high sero-positivity for CMV, Hepatitis B and C infection and specific observations about GVHD with its relation to genetically homogeneous community are discussed. A total of 17 HSCT programs (performing five or more HSCTs annually) exist in nine countries of the EM region. Only six programs are currently reporting to EBMT or IBMTR. A total of 7617 HSCTs including 5701 allogeneic HSCTs have been performed. Due to low HSCT team density (1.5583 teams/10 million inhabitants versus 14.4333 in Europe) and very low HSCT team distribution (0.2729 teams/10,000 sq km area versus <1 to 6 teams in Europe) only 70.8% of total population has access to such a program in EM region. GNI/capita had no clear association with low HSCT activity; however improvement in infrastructure and establishment of EM regional HSCT registry need prioritization.