Pietro Sodani

Bone Marrow Transplantation in Adults with Thalassemia: Treatment and Long‐Term Follow‐Up

Abstract: Current regular blood transfusion programs and chelation treatment have considerably improved survival of patients with thalassemia, which resulted in a larger proportion of adult patients. However, disease‐ and treatment‐related complications in these patients progress over time, causing severe morbidity and shortened life expectancy. Stem cell transplantation still remains the only cure currently available for patients with thalassemia. This study updates transplant outcomes in 107 adult patients with median age of 22 years (range, 17‐35 years) who received bone marrow transplantation (BMT) from human leukocyte antigen (HLA)‐identical related donors between 1988 and 1996 (group A) and describes the results of BMT in 15 adult patients with median age of 21 years (range, 17‐31 years) who were treated with a new treatment protocol (Protocol 26) between 1997 and 2003 (group B). The probability of survival, event‐free survival, nonrejection mortality, and rejection for group A patients were 66%, 62%, 37%, and 4%, respectively, with a median follow‐up of 12 years (range, 8.3‐16.2 years). Group B patients treated with the new protocol had some improvement in thalassemia‐free survival (67%) and lower transplant‐related mortality (27%) than that of previous protocols. However, transplant‐related mortality in these high‐risk patients remains elevated. Current myeloablative BMT in adult patients is characterized by higher transplant‐related toxicity due to an advanced phase of disease. Although this new approach to transplant adult patients with a reduced‐dose intensity‐conditioning regimen has improved thalassemia‐free survival, transplant‐related mortality in these high‐risk patients remains elevated.

Purified T-depleted, CD34+ peripheral blood and bone marrow cell transplantation from haploidentical mother to child with thalassemia.

Fetomaternal microchimerism suggests immunological tolerance between mother and fetus. Thus, we performed primary hematopoietic stem cell transplantation from a mismatched mother to thalassemic patient without an human leukocyte antigen-identical donor. Twenty-two patients with thalassemia major were conditioned with 60 mg/kg hydroxyurea and 3 mg/kg azathioprine from day -59 to -11; 30 mg/m(2) fludarabine from day -17 to -11; 14 mg/kg busulfan starting on day -10; and 200 mg/kg cyclophosphamide, 10 mg/kg thiotepa, and 12.5 mg/kg antithymocyte globulin daily from day -5 to -2. Fourteen patients received CD34(+)-mobilized peripheral blood and bone marrow progenitor cells; 8 patients received marrow graft-selected peripheral blood stem cells CD34(+) and bone marrow CD3/CD19-depleted cells. T-cell dose was adjusted to 2 x 10(5)/kg by fresh marrow cell addback at the time of transplantation. Both groups received cyclosporine for graft-versus-host disease prophylaxis for 2 months after transplantation. Two patients died (cerebral Epstein-Barr virus lymphoma or cytomegalovirus pneumonia), 6 patients reject their grafts, and 14 showed full chimerism with functioning grafts at a median follow-up of 40 months. None of the 14 patients who showed full chimerism developed acute or chronic graft-versus-host disease. These results suggest that maternal haploidentical hematopoietic stem cell transplantation is feasible in patients with thalassemia who lack a matched related donor.

Novel pharmacokinetic behavior of intravenous busulfan in children with thalassemia undergoing hematopoietic stem cell transplantation: a prospective evaluation of pharmacokinetic and pharmacodynamic profile with therapeutic drug monitoring

We prospectively studied the pharmacokinetics (PK) and clinical outcomes of intravenous busulfan (Bu) in 71 children with preexisting liver damage who underwent hematopoietic stem cell transplantation for thalassemia. Intravenous Bu was administered every 6 hours as part of a conditioning regimen with PK-based dose adjustment to target a conservative area under the concentration-versus-time curve (AUC) range (900-1350 microMol*min). The first-dose Bu clearance (CL) was significantly higher than the subsequent daily CL that remained unchanged in the ensuing days. One-third of patients required dose escalation based on dose 1 AUC, whereas dose reduction was needed in the subsequent days. At doses 5, 9, and 13, 78%, 81%, and 87% of patients, respectively, achieved the target range of AUC. A population PK analysis confirmed that the first-dose CL was 20% higher and that body weight was the most important covariate to explain PK variability. Patients with variant GSTA1*B had a 10% lower Bu CL than wild-type. These results suggest that the disease-specific behavior of intravenous Bu PK should be considered for PK-guided dose adjustment in patients with thalassemia, and the use of a conservative AUC range resulted in low toxicity, good engraftment, and good survival rate.

Hematopoietic Stem Cell Transplantation in Thalassemia and Sickle Cell Anemia

The globally widespread single-gene disorders β-thalassemia and sickle cell anemia (SCA) can only be cured by allogeneic hematopoietic stem cell transplantation (HSCT). HSCT treatment of thalassemia has substantially improved over the last two decades, with advancements in preventive strategies, control of transplant-related complications, and preparative regimens. A risk class-based transplantation approach results in disease-free survival probabilities of 90%, 84%, and 78% for class 1, 2, and 3 thalassemia patients, respectively. Because of disease advancement, adult thalassemia patients have a higher risk for transplant-related toxicity and a 65% cure rate. Patients without matched donors could benefit from haploidentical mother-to-child transplantation. There is a high cure rate for children with SCA who receive HSCT following myeloablative conditioning protocols. Novel non-myeloablative transplantation protocols could make HSCT available to adult SCA patients who were previously excluded from allogeneic stem cell transplantation.

Late-Onset Hemorrhagic Cystitis in Children after Hematopoietic Stem Cell Transplantation for Thalassemia and Sickle Cell Anemia: A Prospective Evaluation of Polyoma (BK) Virus Infection and Treatment with Cidofovir

Little is known about late-onset hemorrhagic cystitis (HC) in children, its relationship to BK virus, and treatment with cidofovir (CDV) following hematopoietic stem cell transplantation (HSCT). We prospectively investigated BK virus reactivation in children who underwent HSCT from a matched related donor for thalassemia or sickle cell anemia following busulfan-cyclophosphamide-based conditioning regimens and analyzed risk factors for development of HC and its treatment with CDV. Grade 2-4 HC occurred in 30 patients with a cumulative incidence of 26% (95% confidence interval [CI] = 18%-34%). The cumulative incidences of BK viruria and viremia were 81% (95% CI = 69%-89%) and 28% (95% CI = 18%-40%), respectively. Multivariate analysis revealed that use of antithymocyte globulin (ATG) (hazard ratio [HR] = 10.5; P = .001), peak BK viruria >100,000 copies/mL (HR = 6.2; P = .004), and grade II-IV acute graft-versus-host disease (HR = 5.3; P = .007) were predictive factors for HC. Nineteen patients with HC were given CDV at 1.5 mg/kg/day 3 times a week, or 5 mg/kg/week. The median duration of therapy was 27 days (range, 21-180 days), and a median of 9 doses were given (range, 6-22). All patients had a complete clinical response (CCR), and 69% had a microbiological response at 4 weeks. Eleven patients with BK virus-related HC receiving supportive care also had CCR. The median duration of HC in these patients was similar to that in patients treated with CDV. None of the patients with HC cleared BK viruria when CCR was achieved. We conclude that late-onset HC is more prevalent in children with sustained high BK viruria who are treated with ATG or who develop graft-versus-host disease. Randomized clinical trials are urgently needed to better define the role of CDV in treating BK virus-related HC.

T cell-depleted hla-haploidentical stem cell transplantation in thalassemia young patients

The cure for thalassemia involves correcting the genetic defect in a hematopoietic stem cell that results in reduced or absent β-globin synthesis and an excess of α-globin dimers. Intracellular precipitation and accumulation of α- dimers results in ineffective erythropoiesis and hemolytic anemia. Replacing the abnormal thalassemic marrow with allogeneic normal or heterozygous stem cells carrying the functional gene restores appropriate β-globin chain synthesis.

Bone marrow transplantation for thalassemia from alternative related donors: improved outcomes with a new approach

Bone marrow transplantation (BMT) performance can be limited by a lack of ideal donors, and the role of alternative donor hematopoietic cell transplantation in thalassemia is not well established. Here we used a new treatment protocol (Pc 26.1) in 16 thalassemia patients to perform BMT using phenotypically HLA-identical or 1-antigen-mismatched relatives (related donors [RDs]). We compared these results with HLA-matched sibling (matched sibling donors [MSDs]) BMT in 66 patients. The entire RD group and 88% of MSD group had sustained engraftment. Rejection incidence was 0% in the RD and 12% (95% confidence interval [95% CI], 6%-21%) in MSD groups (P = .15), with respective thalassemia-free survival probabilities of 94% (95% CI, 63%-99%) and 82% (95% CI, 70%-89%) (P = .24). Transplant-related mortality was 6% (95% CI, 1%-26%) in the RD group and 8% (95% CI, 3%-16%) in the MSD group (P = .83). The intensified new protocol was not associated with increased nonhematologic toxicity. The present data show that the Pc 26.1 preparative regimen allows thalassemia patients to safely undergo BMT from RDs who are not HLA-matched siblings, with transplant outcomes similar to patients with MSD grafts.

Positive immunomagnetic CD34+ cell selection in haplo-identical transplants in β-thalassemia patients: removal of platelets using an automated system

BACKGROUND AIMS Immunomagnetic CD34(+) cell selection (ICS) is utilized in autologous and allogeneic transplants. In the first case it is used to reduce the neoplastic contamination of concentrates, while in the second case it is needed to carry out a T-depletion of cell concentrates in order to reduce the incidence of graft-versus-host disease (GvHD) in patients who have undergone haplo-identical transplants. METHODS The efficacy of CliniMACS technology, after reduction of platelet contamination, incubation of monoclonal antibodies (MAb) and successive washings of concentrates, performed in 16 ICS using the standard method without reducing platelet content, was compared with the use of the automated system CytoMate, which was carried out in 46 ICS. RESULTS In the group of ICS carried out after automatic manipulation, a significant statistical difference in purity was noted (91.39% versus 83.57, P = 0.017) compared with the group of ICS carried out with the standard procedure. The same significant difference was noted in relation to the remaining percentages of CD3(+) and CD19(+) cells (2.31% versus 5.68%, P = 0.012, and 1.58% versus 2.71%, P = 0.014, respectively). Recovery of CD34+ cells overlapped in the two groups (70.49% versus 68.39%, P = 0.774). CONCLUSIONS Immunomagnetic selection carried out using the automated procedure was more efficient, producing a purer sample, more efficient T-depletion and optimal reduction of B cells, without influencing cell recovery. Furthermore, conforming to good manufacturing practice (GMP) guidelines, the entire procedure with CytoMate took place in a contamination-controlled environment.

New insights into the pharmacokinetics of intravenous busulfan in children with sickle cell anemia undergoing bone marrow transplantation

Busulfan (Bu) is an integral part of conditioning regimens for patients with sickle cell anemia (SCA) undergoing transplantation. Patients with SCA might predispose to transplant‐related neurological and pulmonary toxicities due to pre‐existing disease‐related cerebrovascular and lung injury. Bu therapy appears to be an important contributing factor in this context.

Cell processing for haplo-identical hematopoietic stem cell transplantation: automated washing and immunomagnetic-positive selection.

BACKGROUND AIMS Immunomagnetic cell selection (ICS) of CD34(+) cells is being used increasingly in allogeneic transplantation in order to reduce T-cell quantity. The aim of this study was to evaluate an automated washing protocol before immunomagnetic selection. METHODS The automated method was compared with a conventional washing procedure. In the study group the cell processing using the automated procedure, both before and after antibody incubation, was performed with a Sepax S-100 device. The efficacy of the automated procedure was compared with the control group, where washing were performed using a standard method. RESULTS The results obtained after pre-incubation washing performed using the automated system showed a total nucleated cell (NC) and CD34(+) cell recovery of 84.87% (71.80-105, SD 8.62; range, standard deviation) and 83.45% (47-109, SD 16.12), respectively. The NC and CD34(+) cell recovery after the pre-incubation washing cycle was performed using the standard method was 75.54% (38.36-97.76, SD 22.5) and 61.51% (30.87-81.79, SD 19.3), respectively. The CD34(+) cell recovery after ICS was 51.27% (13.77-98.82, SD 24.97) and 48.89% (15.57-88.24, SD 25.91) for group 1 and group 2, respectively. The average purity in group 1 was 86.46% (67.4-96.10, SD 13.07) and in group 2 84.97% (58.1-97.8, SD 15.58). CONCLUSIONS The efficacy of the ICS led to an optimal purity without affecting cell recovery, which was higher in group 1. Overall, our data suggest that the automated method is suitable for washing hematopoietic progenitor cell apheresis (HPC-A) concentrates before immunomagnetic cell selection in daily clinical routines.