Evaluations of bioantioxidants in cryopreservation of umbilical cord blood using natural cryoprotectants and low concentrations of dimethylsulfoxide.

Transplantation using hematopoietic stem cells from umbilical cord blood (UCB) is a life-saving treatment option for patients with select oncologic diseases, immunologic diseases, bone marrow failure, and others. Often this transplant modality requires cryopreservation and storage of hematopoietic stem cells (HSC), which need to remain cryopreserved in UCB banks for possible future use. The most widely used cryoprotectant is dimethylsulfoxide (Me(2)SO), but at 37 degrees C, it is toxic to cells and for patients, infusion of cryopreserved HSC with Me(2)SO has been associated with side effects. Freezing of cells leads to chemical change of cellular components, which results in physical disruption. Reactive oxygen species (ROS) generation also has been implicated as cause of damage to cells during freezing. We assessed the ability of two bioantioxidants and two disaccharides, to enhance the cryopreservation of UCB. UCB was processed and subjected to cryopreservation in solutions containing different concentrations of Me(2)SO, bioantioxidants and disaccharides. Samples were thawed, and then analysed by: flow cytometry analysis, CFU assay and MTT viability assay. In this study, our analyses showed that antioxidants, principally catalase, performed greater preservation of: CD34+ cells, CD123+ cells, colony-forming units and cell viability, all post-thawed, compared with the standard solution of cryopreservation. Our present studies show that the addition of catalase improved the cryopreservation outcome. Catalase may act on reducing levels of ROS, further indicating that accumulation of free radicals indeed leads to death in cryopreserved hematopoietic cells.

Evaluation of trehalose and sucrose as cryoprotectants for hematopoietic stem cells of umbilical cord blood.

Bone marrow transplantation (BMT) is a therapeutic procedure that involves transplantation of hematopoietic stem cells (HSC). To date, there are three sources of HSC for clinical use: bone marrow; mobilized peripheral blood; and umbilical cord blood (UCB). Depending on the stem cell source or type of transplantation, these cells are cryopreserved. The most widely used cryoprotectant is dimethylsulfoxide (Me(2)SO) 10% (v/v), but infusion of Me(2)SO-cryopreserved cells is frequently associated with serious side effects in patients. In this study, we assessed the use of trehalose and sucrose for cryopreservation of UCB cells in combination with reduced amounts of Me(2)SO. The post-thawed cells were counted and tested for viability with Trypan blue, the proportion of HSC was determined by flow cytometry, and the proportion of hematopoeitic progenitor cells was measured by a colony-forming unit (CFU) assay. A solution of 30mmol/L trehalose with 2.5% Me(2)SO (v/v) or 60mmol/L sucrose with 5% Me(2)SO (v/v) produced results similar to those for 10% (v/v) Me(2)SO in terms of the clonogenic potential of progenitor cells, cell viability, and numbers of CD45(+)/34(+) cells in post-thawed cord blood cryopreserved for a minimum of 2 weeks. Thus, cord blood, as other HSC, can be cryopreserved with 1/4 the standard Me(2)SO concentration with the addition of disaccharides. The use of Me(2)SO at low concentrations in the cryopreservation solution may improve the safety of hematopoietic cell transplantation by reducing the side effects on the patient.

Hematopoietic stem cell transplantation activity worldwide in 2012 and a SWOT analysis of the Worldwide Network for Blood and Marrow Transplantation Group including the global survey.

Data on 68 146 hematopoietic stem cell transplants (HSCTs) (53% autologous and 47% allogeneic) gathered by 1566 teams from 77 countries and reported through their regional transplant organizations were analyzed by main indication, donor type and stem cell source for the year 2012. With transplant rates ranging from 0.1 to 1001 per 10 million inhabitants, more HSCTs were registered from unrelated 16 433 donors than related 15 493 donors. Grafts were collected from peripheral blood (66%), bone marrow (24%; mainly non-malignant disorders) and cord blood (10%). Compared with 2006, an increase of 46% total (57% allogeneic and 38% autologous) was observed. Growth was due to an increase in reporting teams (18%) and median transplant activity/team (from 38 to 48 HSCTs/team). An increase of 167% was noted in mismatched/haploidentical family HSCT. A Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis revealed the global perspective of WBMT to be its major strength and identified potential to be the key professional body for patients and authorities. The limited data collection remains its major weakness and threat. In conclusion, global HSCT grows over the years without plateauing (allogeneic>autologous) and at different rates in the four World Health Organization regions. Major increases were observed in allogeneic, haploidentical HSCT and, to a lesser extent, in cord blood transplantation.

Bone marrow stroma inhibits proliferation and apoptosis in leukemic cells through gap junction-mediated cell communication.

Normal and leukemic blood cell progenitors depend upon the bone marrow (BM) stroma with which they communicate through soluble and membrane-anchored mediators, adhesive interactions and gap junctions (GJ). Regarding hematopoiesis, it is believed that it can be influenced by connexin expression, but the exact role of GJ in cell death and proliferation is not clear. Using flow cytometry, we monitored the division rate of leukemic cell lines, communicating and not communicating with stromal cell line through GJ. We found that GJ-coupled cells (i) did not proliferate; (ii) were kept in G0; and (iii) were protected from drug-induced apoptosis when compared to either total or uncoupled cell population. We conclude that GJ coupling between stroma and leukemic lymphoblasts prevents proliferation, keeping cells in a quiescent state, thus increasing their resistance to antimitotic drugs. Since GJ are particularly abundant in the sub-endosteal environment, which harbors blood stem cells, we also asked which cells within the normal human BM communicate with the stroma. Using a primary BM stroma cell culture, our results show that 80% of CD34+ progenitors communicate through GJ. We propose that blood cell progenitors might be retained in the low-cycling state by GJ-mediated communication with the hematopoietic stroma.

Late marrow allograft rejection following alpha-interferon therapy for hepatitis in a patient with paroxysmal nocturnal hemoglobinuria.

We describe a case of allograft rejection that occurred 23 months after successful bone marrow transplantation for severe aplastic anemia in a patient with paroxysmal nocturnal hemoglobinuria. The allograft rejection appears to have been induced by recombinant alpha-interferon (rINF-alpha) treatment for non-A, non-B hepatitis that developed 11 months after transplantation. During the 9 months of active hepatitis, the donor graft functioned normally; however, 3 months after rINF-alpha therapy was started, pancytopenia and a chimeric hematopoietic state developed. rINF-alpha was discontinued, cyclosporin A was reintroduced, and autologous bone marrow recovery followed. rINF-alpha treatment may be detrimental to some recipients of allogeneic bone marrow transplants.

CD7+, CD4-/CD8- acute leukemia with t(11;14)(p15;q11) in a child.

A t(11;14)(p15;q11) was the sole chromosome abnormality observed in the malignant cells of a 10-year-old boy with acute leukemia. Morphologically, these cells were classified as L1 by the criteria of the French-American-British Working Group. Cytochemical analysis revealed that the leukemic cells were negative for Sudan Black B, periodic acid Schiff, and esterases, and positive for acid phosphatase. Immunophenotyping disclosed that the cells expressed a very immature antigenic profile [CD34+, CD7+, cytoplasmic CD3+, membrane CD3-, CD4-, and CD8-]. In spite of very intensive chemotherapy, complete remission was never induced, and the child died of progressive disease. The relationship of this case to other reported cases of acute leukemia arising from immature pluripotent hematopoietic cells is discussed.

Deficit of T-cell recovery after allogeneic bone marrow transplantation in chronic myeloid leukemia patients.

The immunological reconstitution that follows bone marrow transplantation (BMT) was studied in 40 leukaemia patients: 19 with chronic myeloid leukaemia (CML), 12 with acute myeloid leukaemia (AML) and the remaining 9 with acute lymphoblastic leukaemia (ALL). The recovery of the CML group was slower than that of the ALL and AML groups. This difference was produced by the T cell compartment, as NK cell activity and B cell numbers did not differ significantly. Factors such as conditioning treatment and graft versus host disease (GVHD) prophylaxis were analysed. Our experience suggests that all leukaemia patients should not be considered as one group when analysing their immunological reconstitution, as factors related to the original disease may affect their outcome.

Stability of human mesenchymal stem cells during in vitro culture: considerations for cell therapy.

Ex vivo expansion and manipulation of human mesenchymal stem cells are important approaches to immunoregulatory and regenerative cell therapies. Although these cells show great potential for use, issues relating to their overall nature emerge as problems in the field. The need for extensive cell quantity amplification in vitro to obtain sufficient cell numbers for use, poses a risk of accumulating genetic and epigenetic abnormalities that could lead to sporadic malignant cell transformation. In this study, we have examined human mesenchymal stem cells derived from bone marrow, over extended culture time, using cytogenetic analyses, mixed lymphocyte reactions, proteomics and gene expression assays to determine whether the cultures would retain their potential for use in subsequent passages. Results indicate that in vitro cultures of these cells demonstrated chromosome variability after passage 4, but their immunomodulatory functions and differentiation capacity were maintained. At the molecular level, changes were observed from passage 5 on, indicating initiation of differentiation. Together, these results lead to the hypothesis that human mesenchymal stem cells cultures can be used successfully in cell therapy up to passage 4. However, use of cells from higher passages would have to be analysed case by case.

Anti-tumor necrosis factor-a for the treatment of steroid-refractory acute graft-versus-host disease.

Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD) occurs in 9 to 50% of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximab)for the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6) for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5). Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600) after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.

Comparison of the toxicity of amphotericin B in 5% dextrose with that of amphotericin B in fat emulsion in a randomized trial with cancer patients.

A multicentric randomized trial was undertaken to compare the toxicity of amphotericin B in 5% dextrose with that of amphotericin B in a fat emulsion (Intralipid) in cancer patients. Group 1 (n = 33) received amphotericin B diluted in 5% dextrose with premedication consisting of promethazine plus an antipyretic. Group 2 (n = 28) received amphotericin B diluted in 20% Intralipid without premedication. Amphotericin B was infused daily at a dose of 1 mg/kg of body weight over a 1-h period to members of both groups for empirical antifungal therapy (in neutropenic patients) or for the treatment of documented fungal infections. The majority of patients (80%) received empirical amphotericin B treatment. The two groups were comparable with regard to age, gender, underlying disease, and the following baseline characteristics: use of other nephrotoxic drugs and serum levels of potassium and creatinine. The median cumulative doses of amphotericin B were 240 mg in group 1 and 245 mg in group 2 (P = 0.73). Acute adverse events occurred in 88% of patients in group 1 and in 71% of those in group 2 (P = 0.11). Forty percent of the infusions in group 1 were associated with fever, compared to 23% in group 2 (P < 0.0001). In addition, patients in group 2 required less meperidine for the control of acute adverse events (P = 0.008), and fewer members of this group presented with hypokalemia (P = 0.004) or rigors (P < 0.0001). There was no difference in the proportions of patients with nephrotoxicity (P = 0.44). The success rates of empirical antifungal treatment were similar in the two groups (P = 0.9). Amphotericin B diluted in a lipid emulsion seems to be associated with a smaller number of acute adverse events and fewer cases of hypokalemia than amphotericin B diluted in 5% dextrose.

Immunological recovery after bone marrow transplantation for severe aplastic anaemia: a Brazilian experience.

Twenty-nine patients with severe aplastic anaemia (SAA) were submitted to bone marrow transplantation (BMT) and their immunological recovery analysed. Total lymphocyte counts, estimation of B lymphocytes, T lymphocytes and their subsets, natural-killer (NK) activity were performed. Cells with the CD8+ phenotype and NK activity were the first signs of immunological recovery, whereas the CD4+ subset recovered later in patients who suffered from acute graft versus host disease (GvHD) and infections. Acute and chronic GvHD, cirrhosis, rejection and HIV viral infection contributed to the persistence of the profound immunodeficiency status observed after BMT. Our results did not differ greatly from the others and confirmed that BMT may be performed in underdeveloped countries despite the difficulties it might pose.

T-lymphocyte function from peripheral blood stem-cell donors is inhibited by activated granulocytes.

BACKGROUND: PBSC transplant provides 10 times more T cells than BMT However, the incidence and severity of acute GvHD is similar among recipients of both types of transplants. Studies in mouse models suggest that the similar clinical outcome in BMT and PBSCT is due to differences in the lymphokine profiles. METHODS: PBMC, PBMC from G-CSF mobilized donors (G-PBMC)and BM mononuclear cells (BM-MC) were analyzed by flow cytometry and ELISA to detect gamma-IFN and IL-4 production. Hematoxylin and eosin staining was used to identify morphology and annexin/propidium-iodide was used for apoptosis assays. RESULTS: We show decreased production of gamma-interferon (85%) and IL-4 (60%) in G-PBMC when compared with either PBMC or BM-MCT cells on ex vivo assays. Surprisingly, 85% of fresh G-PBMC is composed of low-density granulocytes (LDG), which undergo apoptosis after 48 h in culture. At this same time, gamma-IFN production from G-PBMC T cell was reverted. In vitro, G-CSF converts granulocytes into LDGs, able to inhibit T-cell function by H2O2 production, and not through immune-deviation towards a Th2-type phenotype. DISCUSSION: We show that the estimated numbers of Th1 and Th2 cells infused in BMT and PBSCT do not differ significantly. These findings are discussed with reference to the relatively low incidence of acute GvHD in PBSCT shown in the literature. We suggest that these results might depend on the high number of granulocytes and progenitors infused. The potential use of granulocytes as immunosupressive short-term therapy is now being investigated by our group using a mouse experimental model.

Anti-tumor necrosis factor-a for the treatment of steroid-refractory acute graft-versus-host disease

Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD) occurs in 9 to 50 percent of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximab)for the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6) for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5). Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600) after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.