Quantitatively different red cell/nucleated cell chimerism in patients with long-term, persistent hematopoietic mixed chimerism after bone marrow transplantation for thalassemia major or sickle cell disease

BACKGROUND

Persistent mixed chimerism represents a state in which recipient and donor cells stably co-exist after hematopoietic stem cell transplantation. However, since in most of the studies reported in literature the engraftment state was observed in the nucleated cells, in this study we determined the donor origin of the mature erythrocytes of patients with persistent mixed chimerism after transplantation for hemoglobinopathies. Results were compared with the engraftment state observed in singly picked out burst-forming unit - erythroid colonies and in the nucleated cells collected from the peripheral blood and from the bone marrow.

DESIGN AND METHODS

The donor origin of the erythrocytes was determined analyzing differences on the surface antigens of the erythrocyte suspension after incubation with anti-ABO and/or anti-C, -c, -D, -E and -e monoclonal antibodies by a flow cytometer. Analysis of short tandem repeats was used to determine the donor origin of nucleated cells and burst-forming unit - erythroid colonies singly picked out after 14 days of incubation.

RESULTS

The proportions of donor-derived nucleated cells in four transplanted patients affected by hemoglobinopathies were 71%, 46%, 15% and 25% at day 1364, 1385, 1314 and 932, respectively. Similar results were obtained for the erythroid precursors, analyzing the donor/recipient origin of the burst-forming unit - erythroid colonies. In contrast, on the same days of observation, the proportions of donor-derived erythrocytes in the four patients with persistent mixed chimerism were 100%, 100%, 73% and 90%. Conclusions Our results showed that most of the erythrocytes present in four long-term transplanted patients affected by hemoglobinopathies and characterized by the presence of few donor engrafted nucleated cells were of donor origin. The indication that small proportions of donor engrafted cells might be sufficient for clinical control of the disease in patients affected by hemoglobinopathies is relevant, although the biological mechanisms underlying these observations need further investigation.

Unrelated cord blood transplant in children with high-risk acute lymphoblastic leukemia: a long-term follow-up

BACKGROUND AND OBJECTIVES

The aim of this single center study was to assess the impact of pre-transplant factors on long-term follow-up in young patients affected by high-risk acute lymphoblastic leukemia (ALL) who underwent an unrelated cord blood transplant (CBT). The conditioning regimens, graft-versus-host disease (GVHD) prophylaxis and supportive policies were uniform for all patients.

DESIGN AND METHODS

We analyzed the results of CBT performed in 30 patients, aged <18 years, affected by high risk ALL. As conditioning regimen, all patients received 12 Gy fractionated total body irradiation, etoposide, cyclophosphamide and horse anti-lymphocyte globulin. GVHD prophylaxis consisted of 6-methylprednisolone and cyclosporine A. RESULTS The cumulative incidence of engraftment was 93% (95% CI:0.85-0.93). The cumulative incidence of grade III-IV acute and chronic GVHD was 7% (95% CI:0.01-0.19) and 33% (95% CI: 0.17-0.64), respectively. The 9-year cumulative incidence of transplant-related mortality and relapse was 34% (95% CI:0.13-0.45) and 31% (95% CI:0.16-0.61), respectively. The 9-year overall survival, leukemia-free survival and event-free survival were 42% (95% CI:0.52-0.93), 47% (95% CI:0.25-0.61) and 46% (95% CI:0.33-0.61), respectively. A number of CFU-GM <1 x 10(4)/Kg of recipient body weight was the only factor that negatively affected all outcome parameters both in univariate and multivariate analyses.

INTERPRETATION AND CONCLUSIONS

The infused cell dose expressed as in vitro progenitor cell growth represents the most important pre-transplant factor affecting the long-term outcome after an unrelated CBT in young patients with high risk ALL. The number of CFU-GM should thus be considered in the selection process of cord blood units for transplant.

Histone Deacetylase Inhibitor Valproic Acid Enhances the Cytokine-Induced Expansion of Human Hematopoietic Stem Cells

Ex vivo amplification of human hematopoietic stem cells (HSC) without loss of their self-renewing potential represents an important target for transplantation, gene and cellular therapies. Valproic acid is a safe and widely used neurologic agent that acts as a potent inhibitor of histone deacetylase activities. Here, we show that valproic acid addition to liquid cultures of human CD34+ cells isolated from cord blood, mobilized peripheral blood, and bone marrow strongly enhances the ex vivo expansion potential of different cytokine cocktails as shown by morphologic, cytochemical, immunophenotypical, clonogenic, and gene expression analyses. Notably, valproic acid highly preserves the CD34 positivity after 1 week (range, 40-89%) or 3 weeks (range, 21-52%) amplification cultures with two (Flt3L + thrombopoietin) or four cytokines (Flt3L + thrombopoietin + stem cell factor + interleukin 3). Moreover, valproic acid treatment increases histone H4 acetylation levels at specific regulatory sites on HOXB4, a transcription factor gene with a key role in the regulation of HSC self-renewal and AC133, a recognized marker gene for stem cell populations. Overall, our results relate the changes induced by valproic acid on chromatin accessibility with the enhancement of the cytokine effect on the maintenance and expansion of a primitive hematopoietic stem cell population. These findings underscore the potentiality of novel epigenetic approaches to modify HSC fate in vitro.

Intermediate-dose cyclophosphamide and granulocyte colony-stimulating factor is a valid alternative to high-dose cyclophosphamide for mobilizing peripheral blood CD34+ cells in patients with multiple myeloma

Peripheral blood stem cells (PBSC) are widely used in the setting of dose-intensive chemotherapies in patients with multiple myeloma (MM). Although the granulocyte colony-stimulating factor (G-CSF), following chemotherapy or not, is considered the standard growth factor for mobilizing PBSC, the optimal chemotherapeutic regimen still remains to be defined. Cyclophosphamide (CTX) is an effective drug in the treatment of MM which is capable of mobilizing PBSC if followed by growth factors, even though administration of high-dose CTX (7 g/m(2)) results in severe toxicity requiring hospitalization and increasing costs. We have retrospectively analyzed the results obtained in 38 newly diagnosed MM patients treated with 1.2 g/m(2) CTX on days 1 and 3 combined with 40 mg dexamethasone daily for 4 days. The results were compared with those obtained in 25 newly diagnosed MM patients treated with 7 g/m(2) CTX. A higher number of CD34+ cells/kg was collected during the first leukapheresis and a statistically significant lower consumption of G-CSF was observed following two doses of 1.2 g/m(2) CTX compared to the 7 g/m(2) CTX dose. The possibility of treating patients with day-hospital regimens, with a satisfactory yield of hematopoietic cells harvested, may have relevant economic implications for treatment strategies in MM patients.

One-year cyclosporine prophylaxis reduces the risk of developing extensive chronic graft-versus-host disease after allogeneic peripheral blood stem cell transplantation

BACKGROUND AND OBJECTIVES

Chronic graft-versus-host disease (GVHD) remains the most common late complication of allogeneic stem cell transplantation, producing significant long-term morbidity and contributing to a substantial risk of late mortality. Chronic GVHD may be more common, more protracted and less responsive to current treatments after peripheral-blood stem cell (PBSC) transplantation than after bone marrow transplantation. The purpose of this retrospective cohort study was to determine whether the hazard of extensive chronic GVHD after allogeneic PBSC transplantation could be decreased by prolonging cyclosporine A (CsA) prophylaxis over 12 months.

DESIGN AND METHODS

Fifty-seven consecutive patients with hematologic malignancies who had received a PBSC transplant from an HLA-identical sibling were evaluable for chronic GVHD. All patients began CsA tapering at day 50 but 2 different durations of immunosuppression were used: the first 36 patients were allocated to receive a 6-month course with tapering by 5% at weekly intervals (group A), while the following 21 received a 12-month course with tapering by 5% every 2 weeks (group B).

RESULTS

The cumulative incidence of extensive chronic GVHD at 2 years was 69% (95% CI, 53-85%) for group A and 25% (95% CI, 3-47%) for group B with a significantly lower hazard in group B than in group A (HR=0.2; 95% CI, 0.07-0.57; p=0.0009). In multivariate analysis, the 12-month CsA tapering schedule was associated with a significantly decreased risk of extensive chronic GVHD (HR=0.2; 95% CI, 0.06-0.66; p=0.008). The hazard of transplant-related mortality, relapse and failure to survive in remission was not significantly different among the 2 groups.

INTERPRETATION AND CONCLUSIONS

One-year CsA prophylaxis seems to be more effective than the standard six-month CsA regimen at preventing extensive chronic GVHD after PBSC transplant from an HLA-identical sibling. Conclusive assessment of the benefits of such prolonged immunosuppression, in terms of better quality of life and minor morbidity, requires both long-term follow-up to evaluate the rates of relapse and secondary tumors and a randomized setting.

Standard versus alternative myeloablative conditioning regimens in allogeneic hematopoietic stem cell transplantation for high-risk acute leukemia

BACKGROUND AND OBJECTIVES

To analyze the results of standard versus alternative myeloablative conditioning regimens in allogeneic hematopoietic stem cell transplantation for high-risk acute leukemia.

DESIGN AND METHODS

From October 1986 to February 2000, 104 consecutive patients (male: n = 63; median age: 21, range 1.3-44.2 years) with high-risk acute leukemia underwent a non-T-cell depleted graft from an HLA-identical sibling following a standard or alternative myeloablative conditioning regimen. Sixty patients were affected by acute lymphoblastic leukemia (ALL) and 44 by acute myeloid leukemia (AML); the phase at transplant was >= 2nd complete remission (CR) in 76, untreated 1st relapse with < 20% blasts in 11, refractory leukemia or overt resistant relapse in 17. Pre-transplant regimens consisting of either 12 Gy fractionated total body irradiation (TBI) or 16 mg/kg busulphan (BU) combined with cyclophosphamide (CY) were defined standard (n = 38), whereas all other myeloablative regimens (TBI plus 60 mg/kg etoposide and three-drug combinations) were considered alternative (n = 66).

RESULTS

No significant differences in terms of baseline characteristics, incidence and severity of either acute or chronic graft-versus-host disease (GVHD) were observed between the two groups, but a significantly higher proportion of patients prepared with an alternative regimen were not evaluable for chronic GVHD (36% vs 16%) (p = 0.026). Sixty-six patients died, 38 of relapse, 26 of transplant-related mortality (TRM) and 2 of other causes. Thirty-eight patients are still alive with a follow-up ranging from 0.7 to 13.8 years (median, 7.1 years); only 1 of 39 patients who relapsed after transplant is alive in CR at 5.7 years from relapse. At the median follow-up, the actuarial probabilities of overall survival, relapse and TRM for patients conditioned with standard and alternative regimens are respectively 52% vs 25% (95% CI, 36-68% vs 13-37%; p = 0.0163), 34% vs 58% (95% CI, 18-51% vs 43-73%; p = 0.0377) and 25% vs 32% (95% CI, 9-40% vs 19-44%; p = ns). After adjustment for diagnosis, age, period, leukemia phase, duration of 1st CR, GVHD prophylaxis and donor-recipient sex combination, the multivariate analysis showed that alternative regimens are associated with a significantly worse survival (hazard ratio 2.31; p = 0.0071) and relapse rate (hazard ratio 2.75; p = 0.0187).

INTERPRETATION AND CONCLUSIONS

From this retrospective analysis we can conclude that the alternative myeloablative conditioning regimens we used did not improve the outcome of patients transplanted for high-risk acute leukemia.

Self-scheduling and staff incentives: meeting patient care needs in a neonatal intensive care unit

Nursing staff and leadership in a resource-intensive NICU identified an innovative process for covering the unit's scheduling needs. Early concerns about the feasibility of achieving self-scheduling with a large staff were unwarranted. The use of a unit-based committee and the support of the nurse manager allowed us to develop a process that met the needs of the staff members and maintained the staffing standards of the unit. Contributing to the success of the self-scheduling is a mechanism for recognizing and rewarding staff members who adjust their work schedules to meet the needs of the unit. Satisfaction among staff members with self-scheduling is high, and new employees cite the opportunity for self-scheduling as a contributing factor in their decisions to work in the NICU.

Self-scheduling and staff incentives: meeting patient care needs in a neonatal intensive care unit

Nursing staff and leadership in a resource-intensive NICU identified an innovative process for covering the unit's scheduling needs. Early concerns about the feasibility of achieving self-scheduling with a large staff were unwarranted. The use of a unit-based committee and the support of the nurse manager allowed us to develop a process that met the needs of the staff members and maintained the staffing standards of the unit. Contributing to the success of the self-scheduling is a mechanism for recognizing and rewarding staff members who adjust their work schedules to meet the needs of the unit. Satisfaction among staff members with self-scheduling is high, and new employees cite the opportunity for self-scheduling as a contributing factor in their decisions to work in the NICU.