G. Lambertenghi Deliliers

Neuro-glial differentiation of human bone marrow stem cells in vitro

Bone marrow (BM) is a rich source of stem cells and may represent a valid alternative to neural or embryonic cells in replacing autologous damaged tissues for neurodegenerative diseases. The purpose of the present study is to identify human adult BM progenitor cells capable of neuro-glial differentiation and to develop effective protocols of trans-differentiation to surmount the hematopoietic commitment in vitro. Heterogeneous cell populations such as whole BM, low-density mononuclear and mesenchymal stem (MSCs), and several immunomagnetically separated cell populations were investigated. Among them, MSCs and CD90+ cells were demonstrated to express neuro-glial transcripts before any treatment. Several culture conditions with the addition of stem cell or astroblast conditioned media, different concentrations of serum, growth factors, and supplements, used alone or in combinations, were demonstrated to alter the cellular morphology in some cell subpopulations. In particular, MSCs and CD90+ cells acquired astrocytic and neuron-like morphologies in specific culture conditions. They expressed several neuro-glial specific markers by RT-PCR and glial fibrillary acid protein by immunocytochemistry after co-culture with astroblasts, both in the absence or presence of cell contact. In addition, floating neurosphere-like clones have been observed when CD90+ cells were grown in neural specific media. In conclusion, among the large variety of human adult BM cell populations analyzed, we demonstrated the in vitro neuro-glial potential of both the MSC and CD90+ subset of cells. Moreover, unidentified soluble factors provided by the conditioned media and cellular contacts in co-culture systems were effective in inducing the neuro-glial phenotype, further supporting the adult BM neural differentiative capability.

Reduced-intensity conditioning lowers treatment-related mortality of allogeneic stem cell transplantation for chronic lymphocytic leukemia: a population-matched analysis

To elucidate whether reduced-intensity conditioning (RIC) decreases treatment-related mortality (TRM) after allogeneic stem cell transplantation (allo-SCT) for chronic lymphocytic leukemia (CLL), we retrospectively compared 73 RIC cases from a recent EBMT survey with 82 patients from the EBMT database who had undergone standard myeloablative conditioning (MC) for CLL during the same time period. The two populations were matched by adjusting the primary risk factor, the conditioning regimen, in a series of Cox models for age, sex, donor type, remission status at transplant and analyzed for its effect on TRM, relapse incidence, event-free (EFS) and overall survival (OS). After adjustment, a significant reduction of TRM became evident for the RIC population (hazard ratio (HR) 0.4 (95% confidence interval 0.18–0.9); P=0.03). On the other hand, RIC was associated with an increased relapse incidence (HR 2.65 (0.98–7.12); P=0.054). There was no significant difference between RIC and MC in terms of EFS (HR 0.69 (0.38–1.25); P=0.22) and OS (HR 0.65 (0.33–1.28); P=0.21). We conclude that RIC appears to favorably influence TRM after allo-SCT for CLL. This observation, as well as possible detrimental effects of RIC on relapse risk, should be confirmed by prospective studies.

Autologous haematopoietic stem cell transplantation without CD34 + cell selection in refractory Crohn’s disease

Objectives: Autologous haematopoietic stem cell transplantation (HSCT) with CD34+ cell selection has recently been used in the treatment of refractory Crohn’s disease, showing good safety and promising efficacy. We investigated the safety and efficacy of HSCT with unselected peripheral blood stem cells (PBSCs) in moderate–severe refractory Crohn’s disease. Patients: Four patients (three male, one female; age range 26–45 years) with active moderate–severe Crohn’s disease (median Crohn’s Disease Activity Index (CDAI) 319, range 272–345), refractory or intolerant to multiple drugs including infliximab, were enrolled. Interventions: Unselected PBSCs were collected after mobilisation with cyclophosphamide (CTX) 1.5 g/m2 and granulocyte-colony stimulating factor (G-CSF) 10 μg/kg. The conditioning regimen included CTX 50 mg/kg on days −5 to −2 and rabbit anti-thymocyte globulin (ATG) 2.5 mg/kg on days −4 to −2. Main outcome measures: Primary endpoints were toxicity and clinical remission (CDAI<150) at 3 months. Secondary endpoints were clinical and endoscopic response at 3 months and toxicity, clinical and endoscopic remission at 12 months. Results: No improvement or slight deterioration was observed following mobilisation (median CDAI 339, range 258–404). At the third month, the primary endpoint of clinical remission was achieved in all patients, with a median CDAI of 91 (range 56–102), and complete endoscopic remission was achieved in 2/3 patients. After a median follow-up of 16.5 months, 3/4 patients maintained both clinical and endoscopic remission, despite withdrawal of all drugs, and complete fistula closure was observed in all affected patients. No deaths or life-threatening infection occurred. Unexpected adverse events included a perianal abscess after mobilisation in one patient, pleural and pericardial effusions in another and BK virus-related macrohaematuria in another, all rapidly resolved with conservative treatment. Conclusion: Autologous HSCT with unselected PBSC appears to be safe and can induce and maintain remission in previously refractory Crohn’s disease patients.

Syngeneic transplantation in multiple myeloma: a case-matched comparison with autologous and allogeneic transplantation

Twenty-five patients with multiple myeloma received bone marrow grafts (n = 24) or peripheral blood stem cells (n = 1) from twin donors. The outcome was compared in a case-matched analysis to 125 patients who underwent autologous transplantation, and 125 who underwent allogeneic transplantation. Seventeen patients (68%) receiving twin transplants entered complete remission, which was not significantly different from that of autologous (48%) or allogeneic (58%) transplants. The median overall and progression-free survival for the twins was 73 and 72 months, respectively. The overall survival tended to be better (73 vs 44 months) and the progression-free survival was significantly better (72 vs 25 months) than with autologous transplantation and both were significantly better than with allogeneic transplantation. Three of 17 patients who entered complete remission following transplantation had relapsed at follow-up. This relapse rate was significantly lower than following autologous transplantation and similar to the relapse rate with allogeneic transplantation. Only two twins died of transplant-related toxicity. Six further patients died of progressive or relapsing disease. Syngeneic transplantation in multiple myeloma appears to be the treatment of choice if a twin donor is available. A lower relapse risk than in autotransplantation may be due to reinfusion of malignant cells in some patients treated with this modality or to the presence of a graft-versus-myeloma effect in some syngeneic transplants.

Prevalence of metabolic syndrome in long-term survivors of hematopoietic stem cell transplantation

Our purpose was to determine the prevalence and features of metabolic syndrome (MS) in a series of long-term hematopoietic stem cell transplantation (HSCT) survivors. We assessed the clinical, metabolic and endocrinological data, and plasma TNF, leptin, resistin and adiponectin levels relating to 85 HSCT recipients. MS was diagnosed on the basis of the National Cholesterol Education Program-Adult Treatment Panel III criteria. Its prevalence was compared with that observed in an Italian population, and its relationship with the clinical and laboratory parameters was assessed univariately and multivariately. Twenty-nine HSCT recipients had MS instead of the 12.8 expected (P<0.0001), with hypertriglyceridemia being the most common feature. Univariate analysis indicated that high insulin and leptin levels, low-adiponectin levels and hypogonadism were significantly related to a diagnosis of MS; multivariate analysis indicated plasma leptin, insulin resistance, age and hypogonadism. We conclude that HSCT recipients are at increased risk of a form of MS that has particular clinical features. Plasma leptin levels are independently related to MS, thus suggesting that leptin resistance may play a role as a pathogenetic clue, as in other conditions in which MS occurs as a secondary phenomenon. MS deserves consideration as a life-threatening complication in patients who are probably cured of their underlying disease.

Risk of hepatitis B surface antigen seroreversion after allogeneic hematopoietic SCT.

Allogeneic hematopoietic SCT (HSCT) increases the risk of hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg) carriers but the incidence, risk factors and course of HBV reactivation after HSCT in HBsAg-negative/anti-hepatitis B core antigen (anti-HBc)-positive recipients are not well known. A total of 50 HBsAg-negative/anti-HBc-positive HSCT recipients with onco-hematological diseases, underwent sequential clinical and laboratory examinations, including serum HBsAg, during follow-up. Serum HBV DNA collected at HSCT was retrospectively amplified by a sensitive PCR assay. During 17 months of follow-up, six (12%) patients had seroreverted to HBsAg, 7–32 months after HSCT, with 1- and 5-year cumulative rates of 13 and 22%. HBsAg seroreversion was associated with serum HBeAg higher than 8 log10 copies per ml HBV DNA and a 1.5 to 36 fold increase of serum alanine aminotransferase leading to HBeAg-positive chronic hepatitis B in all patients. Patients with chronic onco-hematological disease and long-lasting immunosuppression following HSCT had a higher risk of HBsAg seroreversion independently of serum HBV DNA levels at HSCT. HBsAg-negative/anti-HBc-positive HSCT recipients with chronic onco-hematological disease carry a significant risk of HBsAg seroreversion and HBeAg-positive chronic hepatitis B, independently of serum levels of HBV DNA at transplantation.

Treatment of advanced mycosis fungoides by allogeneic stem-cell transplantation with a nonmyeloablative regimen.

Summary:Given the poor prognosis of patients with advanced cutaneous T-cell lymphoma and the high transplant-related mortality associated with conventional allogeneic bone marrow transplantation, we performed nonmyeloablative transplantation of allogeneic stem cells (ASCT) from HLA-identical siblings in three patients with this disease. All patients achieved full donor engraftment, clearance of clonal T cells leading to durable complete remissions but experienced high incidence of infections, which proved fatal in one case. These results suggest that nonmyeloablative ASCT is a novel and potentially curative therapy for patients with advanced T-cell lymphomas who have a histocompatible sibling.

Sensitivity of human multiple myelomas and myeloid leukemias to the proteasome inhibitor I

The proteasome inhibitor PSI is potently cytotoxic in vitro against human chronic myeloid leukemia (CML) and acute myeloid leukemias (AML). Here, we have tested proteasome inhibitor I (PSI) in a panel of 11 human multiple myeloma (MM) cell lines and found that it has antiproliferative activity, with an IC50 between 4.5 and 557 nM at 48 h. PSI potentiated the toxicity of a number of chemotherapeutic agents in myeloid leukemia but not in MM cell lines, while in combination with therapeutic proteasome inhibitor PS-341 (Bortezomib) it had a synergistic effect. PSI suppressed the growth of AML cell lines more effectively than PS-341. CFU-GM colony assays revealed that CD34+ bone marrow progenitors from CML and AML patients were more sensitive to PSI than those from normal subjects (IC50: 5, 15 and 50 nM for AML, CML and normal, respectively). Moreover, the growth of normal primitive progenitors (LTC-IC) was unaffected by 15 nM PSI (P=0.576). PSI-induced cell death required RNA transcription and protein synthesis, but not DNA replication, was accompanied by the upregulation of Bcl-2 and modest reduction of Bax and Bcl-XL proteins, and involved the activation of caspases 2, 3, 7 and 8. These findings lend additional support to preclinical investigations with PSI.

Bone marrow histology and CD34 immunostaining in the prognostic evaluation of primary myelodysplastic syndromes

The prognostic impact of bone marrow biopsy (BMB) histology and CD34 immunoreactivity was compared with that of the more conventional parameters (the FAB diagnosis, peripheral blood values, percentage of BM blasts and some common prognostic scores) in 100 MDS patients. Statistical correlations among the cytological, haematological, histological and immunohistochemical parameters and their relationship with clinical outcome were searched for. At univariate analysis, FAB classification (P < 0.001), pattern of blastic infiltration at BMB (P < 0.005), presence of CD34+ aggregates (P < 0.0005), percentage of blasts in BM aspirate (P < 0.0001) and percentage of CD34 positivity (P < 0.0001) proved to be linked to leukaemic transformation and, except for FAB classification, retained a high degree of prognostic significance in terms of survival. Leukaemic transformation occurred in 16/18 patients simultaneously presenting ‘large’ blastic infiltrates at BMB and CD34+ aggregates (P < 0.00001); 9/17 evaluable patients died within 12 months of diagnosis (P < 0.001). Discriminant functions for leukaemic transformation and survival did not offer any advantage over univariate analysis in the prognostic work‐up. The results indicate that the size of blastic aggregates and CD34 positivity allowed patients with a worse prognosis to be identified irrespective of their FAB subtype, but the prognostic impact is considerably greater when both parameters are simultaneously taken into account, as testified by the restricted and homogenous subgroup of patients with both ‘large’ and CD34‐positive aggregates.

Endothelial precursors and mature endothelial cells are increased in the peripheral blood of myelodysplastic syndromes

Increased angiogenesis has been demonstrated to be a significant prognostic factor in many solid tumors. In the oncohematological setting, it has been associated with myelodysplastic syndromes (MDS), chronic myeloid leukemia, acute lymphoid, and myeloid leukemias. Recently, increased circulating endothelial cells (CECs) have been associated with breast cancer and non-Hodgkin lymphoma (NHL). Based on these premises we analysed total and activated CECs, and endothelial precursors (CEPs) in 50 MDS patients and 20 healthy donors. CECs and CEPs were quantified by flow cytometry. CEC levels were compared with bone marrow (BM) microvessel density (MVD). In addition, some angiogenic factors, namely vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and soluble VEGF-Receptor2 (VEGFR2), were tested in the sera from 25 MDS patients. Total, activated CECs and CEPs were significantly increased in MDS when compared to control group (p<0.0001); whereas in the MDS cases no association was found with French--American--British (FAB), International Prognostic Scoring System (IPSS) subtypes or survival. Patients with higher CECs also showed higher MVD. Among the cytokines analysed, sVEGFR2 was significantly higher in the lower IPSS risk classes, while the levels of bFGF directly correlated with total and activated CECs. Taken together these data strengthen the hypothesis of a possible role of angiogenesis in MDS pathogenesis.