High-dose immunosuppressive therapy and autologous progenitor cell transplantation for systemic sclerosis

High-dose immunosuppressive therapy aimed at immunoablation, given together with autologous stem cell transplantation, has resulted in prolonged (>3 years) improvements of skin thickening and functional ability, together with a stabilization of pulmonary function in two-thirds of treated patients with severe systemic sclerosis. Transplant-related mortality occurred in 17% of the first cohort of 41 patients reported to the European Group for Blood and Marrow Transplantation, which included cases from the United States, but this figure has dropped to 8.7% in a recent retrospective analysis of 57 transplants performed in Europe. Similar outcomes were reported in multicentre studies from the United States of 19 patients, and from France of 12 patients, with improvements in skin scores and functional assessments, together with a stabilization of internal organ dysfunction. Based on the results of these phase I/II studies, multicentre prospective randomized trials are being planned or are in progress in Europe and the United States employing uniform patient entry criteria and outcome parameters. The aim of these studies is to compare the clinical benefits and safety of transplant regimens versus conventional chemotherapy in patients with severe systemic sclerosis who are at risk of life-threatening organ failure and premature mortality. Eligibility criteria include a diagnosis of diffuse systemic sclerosis of recent onset and major organ (heart, kidney, lungs) involvement according to predefined criteria. The prospective randomized trials address two issues related to the treatment of severe systemic sclerosis: is intensive immunosuppressive therapy superior to conventional therapy, and can self-tolerance be re-established?

Impact of unrelated donor status on the incidence and outcome of cytomegalovirus infections after non-myeloablative allogeneic stem cell transplantation

Little is known about the impact of cytomegalovirus (CMV) infections that occur after human leucocyte antigen (HLA)-matched unrelated donor (MUD) non-myleoablative haematopoietic stem cell transplantation (HCT). We analysed the incidence, onset and outcomes of CMV infections in 59 recipients of MUD and in 109 recipients of HLA-matched related donor (MRD) allogeneic HCT following non-myeloablative conditioning containing 2 Gy total body irradiation and fludarabine. In CMV seropositive recipients, antigenaemia occurred in 68% (MUD) and in 49% (MRD, P = 0.08); there were no differences in the maximum levels of CMV antigenaemia and the time to cessation with antiviral therapy. CMV viraemia by culture was more common in MUD compared with MRD HCT recipients in univariate analysis (26% vs. 6%, P = 0.01), however, this difference was not detectable after controlling for other factors. The rates of CMV disease in the first 100 d were similar in MUD (9%) and MRD (5%) HCT recipients. CMV disease tended to occur earlier in the MUD compared with the MRD recipients (median day 41 vs. day 80). Beyond day 100, rates of CMV disease remained similar in both cohorts (cumulative incidence: MUD 21% and MRD 14%). The 30-d and 1-year survivals after CMV disease diagnosis were not significantly different in both groups. Thus, there appeared to be a trend toward increased CMV reactivation in MUD compared with MRD non-myeloablative allogeneic HCT recipients; however, these differences did not reach statistical significance in this cohort and preemptive therapy was similarly effective in preventing CMV diseases.

Treatment options for newly diagnosed patients with chronic myeloid leukemia

Chronic myeloid leukemia (CML) is characterized by a 9:22 translocation resulting in production of a chimeric BCR-ABL fusion protein that has constitutive tyrosine kinase activity and drives leukemic transformation. Imatinib mesylate, a selective inhibitor of BCR-ABL, has been introduced into clinical trials with favorable toxicity and impressive activity at all disease stages. In a phase III study of diagnosed chronic phase CML, imatinib mesylate was superior to interferon plus cytarabine in cytogenetic response, freedom from disease progression, and tolerability. Hematopoietic stem cell transplantation remains the only established cure for CML. Recent reports show continued improvements with survivals after matched sibling grafts greater than 80% at 3 to 5 years. Therefore, recent advances in conventional and transplant therapy have improved treatment options for newly diagnosed patients. Sensitive and specific monitoring techniques developed for CML may help further refine treatment with regard to using these and other emerging therapies.

High-dose immunosuppressive therapy and autologous peripheral blood stem cell transplantation for severe multiple sclerosis

There were 26 patients enrolled in a pilot study of high-dose immunosuppressive therapy (HDIT) for severe multiple sclerosis (MS). Median baseline expanded disability status scale (EDSS) was 7.0 (range, 5.0-8.0). HDIT consisted of total body irradiation, cyclophosphamide, and antithymocyte globulin (ATG) and was followed by transplantation of autologous, granulocyte colony-stimulating factor (G-CSF)-mobilized CD34-selected stem cells. Regimen-related toxicities were mild. Because of bladder dysfunction, there were 8 infectious events of the lower urinary tract. One patient died from Epstein-Barr virus (EBV)-related posttransplantation lymphoproliferative disorder (PTLD) associated with a change from horse-derived to rabbit-derived ATG in the HDIT regimen. An engraftment syndrome characterized by noninfectious fever with or without rash developed in 13 of the first 18 patients and was associated in some cases with transient worsening of neurologic symptoms. There were 2 significant adverse neurologic events that occurred, including a flare of MS during mobilization and an episode of irreversible neurologic deterioration after HDIT associated with fever. With a median follow-up of 24 (range, 3-36) months, the Kaplan-Meier estimate of progression (>/= 1.0 point EDSS) at 3 years was 27%. Of 12 patients who had oligoclonal bands in the cerebrospinal fluid at baseline, 9 had persistence after HDIT. After HDIT, 4 patients developed new enhancing lesions on magnetic resonance imaging of the brain. The estimate of survival at 3 years was 91%. Important clinical issues in the use of HDIT and stem cell transplantation for MS were identified; however, modifications of the initial approaches appear to reduce treatment risks. This was a heterogeneous high-risk group, and a phase 3 study is planned to fully assess efficacy.

Epstein-Barr virus-associated posttransplantation lymphoproliferative disorder after high-dose immunosuppressive therapy and autologous CD34-selected hematopoietic stem cell transplantation for severe autoimmune diseases

High-dose immunosuppressive therapy followed by autologous hematopoietic stem cell transplantation (HSCT) is currently being evaluated for the control of severe autoimmune diseases. The addition of antithymocyte globulin (ATG) to high-dose chemoradiotherapy in the high-dose immunosuppressive therapy regimen and CD34 selection of the autologous graft may induce a higher degree of immunosuppression compared with conventional autologous HSCT for malignant diseases. Patients may be at higher risk of transplant-related complications secondary to the immunosuppressed state, including Epstein-Barr virus (EBV)-associated posttransplantation lymphoproliferative disorder (PTLD), but this is an unusual complication after autologous HSCT. Fifty-six patients (median age, 42 years; range, 23-61 years) with either multiple sclerosis (n = 26) or systemic sclerosis (n = 30) have been treated. The median follow-up has been 24 months (range, 2-60 months). Two patients (multiple sclerosis, n = 1; systemic sclerosis, n = 1) had significant reactivations of herpesvirus infections early after HSCT and then developed aggressive EBV-PTLD and died on days +53 and +64. Multiorgan clonal B-cell infiltrates that were EBV positive by molecular studies or immunohistology were identified at both autopsies. Both patients had positive screening skin tests for equine ATG (Atgam) and had been converted to rabbit ATG (Thymoglobulin) from the first dose. Of the other 54 patients, 2 of whom had partial courses of rabbit ATG because of a reaction to the intravenous infusion of equine ATG, only 1 patient had a significant clinical reactivation of a herpesvirus infection (herpes simplex virus 2) early after HSCT, and none developed EBV-PTLD. The T-cell count in the peripheral blood on day 28 was 0/microL in all 4 patients who received rabbit ATG; this was significantly less than in patients who received equine ATG (median, 174/microL; P =.001; Mann-Whitney ranked sum test). Although the numbers are limited, the time course and similarity of the 2 cases of EBV-PTLD and the effect on day 28 T-cell counts support a relationship between the development of EBV-PTLD and the administration of rabbit ATG. The differences between equine and rabbit ATG are not yet clearly defined, and they should not be considered interchangeable in this regimen without further study.

Effect of c-mpl ligands after total body irradiation (TBI) with and without allogeneic hematopoietic stem cell transplantation: low-dose TBI does not prevent sensitization

This study investigates the potential role of the recombinant c-mpl ligands (recombinant human thrombopoietin [rhTPO] and pegylated recombinant human megakaryocyte growth and development factor [PEG-rhMGDF]) on the recovery of platelet counts after TBI with and without allogeneic hematopoietic stem cell transplantation (HSCT) in an established canine model. Initially, 3 cohorts, each with 2 nonirradiated dogs, received increasing doses of rhTPO (5 microg/kg per day; 10 microg/kg per day; 20 microg/kg per day) for 7 days to determine the optimal dose. The dose of 10 microg/kg per day of rhTPO was selected for subsequent studies. Ten dogs then received either rhTPO or placebo for 28 days after 200 cGy TBI without HSCT. The rhTPO group had fewer days with platelet counts <20,000/microL (9.8 days versus 17.8 days, P < .05) and significantly increased granulocyte counts (n = 5) compared to the controls (n = 5). RhTPO-specific antibodies developed in 2 dogs, which caused a significant but transient decrease of the platelet counts. Retreatment of these sensitized dogs with rhTPO resulted in profound transient decreases in platelet counts. In the next study, 20 dogs received either PEG-rhMGDF or placebo for 21 days after 920 cGy TBI and allogeneic HSCT. The median time to platelet recovery (>20,000/microL) for the PEG-rhMGDF group (n = 10) was 14.0 days compared to 15.5 days for the control group (n = 10; log rank, P = .35). There were no significant differences in the total time to platelet counts <20,000/microL or in the time to recover neutrophil counts >500/microL. The effects of rhTPO on recovery of platelet and granulocyte counts after sublethal TBI were modest, and no effects of PEG-rhMGDF were observed on hematopoietic recovery after high-dose TBI and allogeneic HSCT. The significant effect that rhTPO-specific antibodies had on the platelet counts may limit the clinical role of recombinant c-mpl ligands unless sensitization can be prevented.

High-dose immunosuppression and hematopoietic stem cell transplantation in autoimmune disease: clinical review

Since 1996, a number of investigators have carried out phase I-II studies of high-dose immunosuppression with autologous hematopoietic stem cell transplantation (HSCT) in autoimmune diseases. Most of this activity has been in studies of multiple sclerosis (MS), systemic sclerosis (SSc), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and juvenile idiopathic arthritis (JIA). Supported by animal models of antigen-induced autoimmunity, the rationale of HSCT is to time-shift the clinical autoimmunity to an earlier period, restoring self-tolerance. Even with the considerable experience of more than 200 transplantations since 1996, it is difficult to judge the optimal approach. This difficulty is in part because of the multiplicity of centers and protocols and the variability in patient eligibility and assessment, the extent of T-cell depletion, and the intensity of the preparatory regimens used. Other than that found in RA, treatment-related mortality has been higher than expected: 17% in SSc (with an additional 10% mortality from progressive disease), 13% in SLE, 13% in JIA, and 8% in MS. Protocol changes to improve safety have been instituted. These changes include the avoidance of high-dose rabbit antithymocyte serum in patients who received T-cell-depleted grafts, use of corticosteroids with granulocyte colony-stimulating factor during stem cell mobilization and as prophylaxis for the engraftment syndrome in MS, lung radiation shielding in SSc, and multiple precautions against the macrophage activation syndrome in JIA. Responses to primary and secondary endpoints have been seen, and there is a consensus among investigators and regulatory bodies that the time has come for randomized phase II-III studies. Each disease presents distinct difficulties: in MS, restriction of eligibility to patients with active inflammatory disease; in SSc, formulation of cardiopulmonary eligibility criteria to decrease risk; in SLE, judgment of whether HSCT adds any advantage to high-dose nonmyeloablative immunosuppressive treatment alone; and in RA, enhancement of response durability. All prospective randomized studies in these diseases must address problems in selection of the comparison nontransplantation treatment and appropriate stopping rules, particularly with treatment arms of unequal risk. Parallel trials in Europe and in the United States are in the late stages of design.

Incidence and outcome of bacterial and fungal infections following nonmyeloablative compared with myeloablative allogeneic hematopoietic stem cell transplantation: a matched control study

Infections contribute significantly to morbidity and mortality after myeloablative allogeneic hematopoietic stem cell transplantation (HSCT). Whether recipients of nonmyeloablative HSCT have different posttransplantation infection risk was unknown. We therefore analyzed the incidence and risk of bacteremia during the first 100 days and of fungal infection during the first 365 days posttransplantation for 56 consecutive patients with hematological malignant disease who received nonmyeloablative HSCT (case patients). We compared the results with those among 112 control patients who received conventional myeloablative HSCT during the same years (January 1997-April 2000). Control patients were matched (2:1) for cytomegalovirus (CMV) risk group, HSC source, donor type, age, and underlying disease. Most donors (93%) were HLA-matched and related. Case patients had shorter periods of neutropenia (absolute neutrophil count, <100/mm3) than did control patients (median, 0 days; range, 0-11 versus 9 days; range, 4-25; P < .0001). This finding was associated with fewer episodes of bacteremia during the first 30 days (9% versus 27%; P = .01) and a trend to fewer episodes of bacteremia during the first 100 days posttransplantation (27% versus 41%, P = .07). Overall survival was significantly improved in case patients compared with control patients (day 100, 93% versus 81%; P = .04). During the first year posttransplantation, invasive aspergillosis occurred at a similar rate (case patients, 15%; control patients, 9%; P value not significant). Multivariate risk factor analyses identified neutropenia and CMV disease as the major factors associated with bacteremia and aspergillosis, respectively. We conclude that shorter periods of severe neutropenia in nonmyeloablative HSCT are associated with decreased risk of early bacteremia, although risk of fungal infection late after HSCT persists. This risk is an important consideration for the future development of preventive strategies.

Nonmyeloablative allogeneic hematopoietic stem cell transplantation for congenital sideroblastic anemia

Congenital sideroblastic anemia (CSA) is a dyserythropoietic disorder that leads to transfusion dependency and subsequent iron overload. Nonmyeloablative allogeneic hematopoietic stem cell transplantation (NST) was performed for a patient with CSA, who had contraindications to conventional allografting. Conditioning was fludarabine, low-dose total body irradiation and antithymocyte globulin, followed by peripheral blood stem cell transplant. Cyclosporine and mycophenolate mofetil were used for graft-versus-host disease prophylaxis. Complete donor chimerism was observed day +131. Early after transplant, the patient became transfusion independent, allowing a regular phlebotomy program. On day +190, refractory lactic acidosis followed by fatal cardiovascular collapse developed, without evidence of infection. Data from this case demonstrates that NST may correct the erythropoietic defect of CSA.

Allografting after nonmyeloablative conditioning as a treatment after a failed conventional hematopoietic cell transplant

Outcomes with conventional allogeneic hematopoietic cell transplantation (HCT) after failed HCT are typically poor. To reduce transplantation-related mortality (TRM), 55 patients (median age, 43 years; range, 18-69 years) who had failed conventional autologous (n = 49), allogeneic (n = 4), or syngeneic (n = 2) HCT received human leukocyte antigen-matched related (n = 31) or unrelated (n = 24) donor allografts after nonmyeloablative conditioning with 2 Gy of total body irradiation or 2 Gy of total body irradiation and 90 mg/m(2) of fludarabine. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. One rejection occurred. Thirty-three patients died a median of 127 days (range, 7-834 days) after HCT: 21 of relapse, 11 of TRM, and 1 of suicide. The TRM rate on day 100 was 11% with an estimated 1-year TRM rate of 20% (95% confidence interval [CI], 9% to 31%). The median follow-up among the 22 survivors is 368 days (range, 173-796 days). Seventeen of 22 survivors are progression-free. One-year estimates of overall and progression-free survival rates are 49% (95% CI, 35% to 62%) and 28% (95% CI, 16% to 41%), respectively. Untreated disease at the time of allografting after nonmyeloablative conditioning increased the risk of death (hazard ratio = 2.4; P =.04). Although the length of follow-up is still short, it appears that encouraging outcomes can be achieved with nonmyeloablative conditioning in patients expected to have poor outcomes with conventional allografting.

Purified canine CD34+Lin- marrow cells transduced with retroviral vectors give rise to long-term multi-lineage hematopoiesis

Human CD34+ cells have been shown to retain long-term hematopoietic engrafting potential in preclinical and clinical studies. However, recent studies of human and murine CD34- stem cells suggest that these are functionally important early progenitors. Using autologous transplantation, we investigated whether canine CD34 and CD34- marrow cells could be transduced and give rise to long-term hematopoiesis. CD34+Lin- and CD34-Lin- cell populations purified by fluorescence-activated cell sorting were separately cocultivated with retroviral vectors LN (CD34+Lin-) and LNY (CD34-Lin-), which carry the neomycin (neo) gene. After myeloablative total body irradiation (920 cGy), 3 dogs received transplants of both CD34+Lin- cells and CD34-Lin- cells and 2 dogs received only CD34-Lin- cells. Untransduced autologous marrow cells were given to ensure hematopoietic recovery. Using CFU-C assays, transduction efficiencies of CD34+Lin- cells ranged from 6% to 18% with no CFU-C formation from CD34-Lin- cells. PCR-based detection of the neo gene from WBCs was used to detect transduced cells weekly after transplantation. Additional PCR studies in 3 dogs given both CD34+Lin- and CD34-Lin- cells were performed on monocytes, granulocytes, and T cells (2 dogs, one at 7.5 months and the other at 9 months) and granulocytes (1 dog at 12 months). LN was detected up to 12 months posttransplantation in WBCs and mono-myeloid and lymphoid populations from 3 dogs receiving transplants of transduced CD34+Lin- cells. LNY was not detected at any time after transplantation in 5 dogs that received transduced CD34-Lin- cells. Whereas canine CD34+Lin- marrow cells contributed to long-term multilineage hematopoiesis, progeny of CD34-Lin- progenitor cells were not detected after transplantation in these experiments.

Low-dose total body irradiation (TBI) and fludarabine followed by hematopoietic cell transplantation (HCT) from HLA-matched or mismatched unrelated donors and postgrafting immunosuppression with cyclosporine and mycophenolate mofetil (MMF) can induce durable complete chimerism and sustained remissions in patients with hematological diseases

Toxicities of high-dose conditioning regimens have limited the use of conventional unrelated donor hematopoietic cell transplantation (HCT) to younger, medically fit patients. Based on preclinical studies, an HCT approach has been developed for elderly or medically infirm patients with HLA-matched or mismatched unrelated donors. In this study, 52 patients with hematological diseases were included. Most (88%) had preceding unsuccessful conventional HCT or refractory/advanced disease. Patients were treated with fludarabine 30 mg/m(2)/d from days -4 to -2, 2 Gy total body irradiation on day 0, cyclosporine at 6.25 mg/kg twice daily from day -3, and mycophenolate mofetil at 15 mg/kg twice daily from day 0. Durable donor chimerism was attained in 88% of the patients. By day 28, a median of 100% of CD56(+) cells were of donor origin. Granulocyte and T-cell donor chimerism increased to medians of 100% on day 56 and day 180 (range, 55%-100%), respectively. Acute GVHD, grade II, was seen in 42% (CI, 29%-56%); grade III in 8% (CI, 0%-15%); and grade IV in 13% (CI, 4%-23%) of patients; it was fatal in 9%. The 100-day transplantation-related mortality was 11%. Complete remissions, including molecular remissions, were seen in 45% of patients with measurable disease before transplantation. Mortality from disease progression was 27% at one year. With a median follow-up of 19 months, 18 of the 52 patients (35%) were alive and 25% were in remission. HCT from HLA-matched or mismatched unrelated donors can be performed with a reduced intensity conditioning regimen in patients ineligible for conventional HCT.

Hematopoietic Cell Transplantation for Benign Hematological Disorders and Solid Tumors

Allogeneic hematopoietic cell transplantation (HCT) has been successfully used as replacement therapy for patients with aplastic anemia and hemoglobinopathies. Both autologous and allogeneic HCT following high-dose chemotherapy can correct manifestations of autoimmune diseases. The impressive allogeneic graft-versus-tumor effects seen in patients given HCT for hematological malignancies have stimulated trials of allogeneic immunotherapy in patients with otherwise refractory metastatic solid tumors. This session will update the status of HCT in the treatment of benign hematological diseases and solid tumors.

In Section I, Dr. Rainer Storb reviews the development of nonmyeloablative conditioning for patients with severe aplastic anemia who have HLA-matched family members. He also describes the results in patients with aplastic anemia given HCT from unrelated donors after failure of responding to immunosuppressive therapy. The importance of leuko-poor and in vitro irradiated blood product transfusions for avoiding graft rejection will be discussed.

In Section II, Dr. Guido Lucarelli reviews the status of marrow transplantation for thalassemia major and updates results obtained in children with class I and class II severity of thalassemia. He also describes results of new protocols for class III patients and efforts to extend HCT to thalassemic patients without HLA-matched family members.

In Section III, Dr. Peter McSweeney reviews the current status of HCT for severe autoimmune diseases. He summarizes the results of autologous HCT for systemic sclerosis, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus, and reviews the status of planned Phase III studies for autologous HCT for these diseases in North America and Europe. He also discusses a possible role of allogeneic HCT in the treatment of these diseases.

In Section IV, Dr. Richard Childs discusses the development and application of nonmyeloablative HCT as allogeneic immunotherapy for treatment-refractory solid tumors. He reviews the results of pilot clinical trials demonstrating graft-versus-solid tumor effects in a variety of metastatic cancers and describes efforts to characterize the immune cell populations mediating these effects, as well as newer methods to target the donor immune system to the tumor.

Non-myeloablative allografting from human leucocyte antigen-identical sibling donors for treatment of acute myeloid leukaemia in first complete remission

Many patients with acute myeloid leukaemia (AML) in first complete remission (CR1) are ineligible for allogeneic transplantation as a result of age or medical problems other than leukaemia. Eighteen patients (median age 59 years, range 36-73 years) with de novo (n = 13) and secondary (n = 5) AML in morphological CR1, who were not candidates for conventional allografting, received non-myeloablative peripheral blood stem cell transplants from human leucocyte antigen identical sibling donors after conditioning with 2 Gy total body irradiation (TBI; n = 10) or 2 Gy TBI and 90 mg/m2 of fludarabine (n = 8). Postgrafting immunosuppression was with cyclosporine and mycophenolate mofetil. Two rejections were observed in patients not given fludarabine and one died with relapse. Overall, 10 patients died between 77 and 841 d, seven from relapse and three from non-relapse mortality (NRM). Day +100 NRM was 0% with a 1-year estimated NRM of 17%[95% confidence interval (CI) 0-35%]. The median follow-up among the eight survivors was 766 d (range, 188-1141 d). Seven of these eight survivors remain in complete remission (CR). One-year estimates of overall and progression-free survivals were 54% (95% CI 31-78%) and 42% (95% CI 19-66%) respectively. While follow-up is short, this analysis demonstrates that the procedure is sufficiently safe to be studied in a wider group of patients.

Transplantation of X-linked severe combined immunodeficient dogs with CD34+ bone marrow cells

X-linked severe combined immunodeficiency (X-SCID) is the most common form of human SCID and is caused by mutations in the common gamma chain (gammac), a shared component of the interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15, and IL-21 receptors. BMT for human X-SCID results in engraftment of donor T-cells and reconstitution of normal T-cell function but engraftment of few, if any, donor B-cells and poor reconstitution of humoral immune function. Canine X-SCID is also caused by mutations in the yc and has an immunological phenotype identical to that of human X-SCID. We have previously reported that transplantation of nonconditioned X-SCID dogs with unfractionated histocompatible bone marrow results in engraftment of both donor B- and T-cells and reconstitution of normal T-cell and humoral immune function. In this study, we assessed the ability of purified canine CD34+ bone marrow cells to reconstitute lymphoid populations after histocompatible BMT in 6 nonablated X-SCID dogs. All dogs showed engraftment of donor T-cells, with T-cell regeneration occurring through a thymic-dependent pathway, and had reconstituted normal T-cell function. In contrast to our previous studies, only 3 dogs had engraftment of donor B-cells and reconstituted normal antigen-specific B-cell function post-BMT. The variable donor B-cell engraftment and reconstitution of normal humoral immune function observed in this study are similar to the outcomes observed in the majority of human X-SCID patients following BMT. This study demonstrates that canine CD34+ cells contain progenitors capable of immune reconstitution and is the first study to document the ability of CD34+ bone marrow cells to reconstitute normal B- and T-cell function in a nonablated large-animal model of BMT. This study also demonstrates that the quality of immune reconstitution following CD34+ BMT may be dosage dependent Thus canine X-SCID provides a large-animal preclinical model that can be used not only to determine the optimal conditions for both donor B- and T-cell engraftment following CD34 BMT, but also to develop and evaluate strategies for gene therapy protocols that target CD34 cells.

High-dose immunosuppressive therapy for severe systemic sclerosis: initial outcomes

Systemic sclerosis (SSc) is a multisystem disease of presumed autoimmune pathogenesis for which no proven effective treatment exists. High-dose immunosuppressive therapy (HDIT) has been proposed as an investigational treatment for severe autoimmune diseases. Nineteen patients with poor-prognosis SSc underwent HDIT. The median age was 40 years (range, 23-61 years), the median modified Rodnan skin score (a measure of dermal sclerosis) was 31, and the median DLCO was 57%. Conditioning therapy involved 800 cGy total body irradiation (TBI) (+/- lung shielding to approximately 200 cGy), 120 mg/kg cyclophosphamide, and 90 mg/kg equine antithymocyte globulin. CD34-selected granulocyte-colony-stimulating factor-mobilized autologous blood stem cells provided hematopoietic rescue. With median follow-up at 14.7 months, the Kaplan-Meier estimated 2-year survival rate was 79%. Three patients died of treatment complications and one of disease progression. Two of the first 8 patients had fatal regimen-related pulmonary injury, a complication not found among 11 subsequent patients who received lung shielding for TBI. Overall, internal organ functions were stable to slightly worse after HDIT, and 4 patients had progressive or nonresponsive disease. As measured by modified Rodnan skin scores and modified health assessment questionnaire disability index (mHAQ-DI) scores, significant disease responses occurred in 12 of 12 patients evaluated at 1 year after HDIT. In conclusion, though important treatment-related toxicities occurred after HDIT for SSc, modifications of initial approaches appear to reduce treatment risks. Responses in skin and mHAQ-DI scores exceed those reported with other therapies, suggesting that HDIT is a promising new therapy for SSc that should be evaluated in prospective randomized studies.

Reduced-intensity allogeneic transplantation for lymphoma

Reduced-intensity allogeneic transplants are promising, increasingly used treatments for hematologic malignancies, exploiting graft-versus-tumor effects for eradicating malignancies. This article reviews approximately 40 published reports of reduced-intensity allogeneic transplants in lymphomas. Overall, reduced-intensity allogeneic transplants have been well tolerated and have produced encouraging results despite a diversity of transplant approaches used largely in heavily pretreated and older patients. Of 368 lymphoma patients who underwent reduced-intensity allogeneic transplants, 66.3% had responses, most of which were complete. Many had chemotherapy-refractory lymphomas, including some that relapsed after autologous transplants. Although the short follow-up periods of many studies do not permit assessments of response duration, protracted remissions were reported in some studies. Additionally, some patients entered molecular remissions, suggesting that graft-versus-tumor effects could, by themselves, cure some lymphomas. Graft-versus-host disease is the major risk of reduced-intensity allogeneic transplants, and treatment methods need refinement to reduce transplant risks while preserving graft-versus-tumor effects. Controlled trials involving patients with earlier-stage disease appear warranted to define better the role of reduced-intensity allogeneic transplants in treating lymphomas.

Related and unrelated nonmyeloablative hematopoietic stem cell transplantation for malignant diseases

Patients with advanced hematological malignancies ineligible for conventional myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) due to advanced age or medical contraindications were enrolled in multi-center study to investigate the safety and efficacy of nonmyeloablative HSCT using a 2 Gy total body irradi ation (TBI)-based regimen. A total of 192 patients (median age 55) were treated with HLA-matched sibling peripheral blood stem cell (PBSC) grafts, and 63 patients (median age 53) received a 10 of 10 HLA-antigen matched unrelated donor (URD) HSCT (PBSC graft, n = 48; marrow graft, n = 15). Diagnoses included multiple myeloma (n = 61), myelodysplastic syndrome (n = 55), chronic myeloid leukemia (n = 31), non-Hodgkin lymphoma (n = 31), acute myeloid leukemia (n = 28), chronic lymphocytic leukemia (n = 24), Hodgkin Disease (n = 14). The conditioning regimen was fludarabine 30 mg/m2/d x 3 days and 2 Gy TBI. Ninety-five related HSCT patients received 2 Gy TBI without fludarabine. Postgrafting immunosuppression was combined mycophenolate mofetil an cyclosporine. Transplants were well tolerated with a median of 0 days of hospitalization in the first 60 days for eligible patients. For related HSCT recipients, median follow-up was 289 (100-1,188) days. Nonfatal graft rejection occurred in 6.8%. Of those with sustained engraftment, graft-versus-host disease (GVHD) occurred in 49% (33% grade II, 11% grade III, 5% grade IV). Day-100 non-relapse mortality was 6%. Overall, 59% (114/192) of patients were alive. The relapse/disease progression mortality was 18%, and non-relapse mortality was 22%. The projecte 2-year survival and progression-free survival were 50% and 40%. For the URD HSCT recipients, median follow-up was 190 (100-468) days. Graft rejection occurred in 27% (17/63) of patients, mostly in recipients of marrow grafts (9/15). Acute GVHD occurred in 63% (50% grade II, 13% grade III) of 46 engrafted patients. Chronic GVHD requiring therapy occurred in 50% of patients. Of the 63 URD HSCT patients, 54% were alive, 37% in CR, 3% PR, and 14% with disease progression or relapse. Related and unrelated nonmyeloablative HSCT is feasible and potentially curative in patients with advanced hematological malignancies who have no other treatment options.

Renal dysfunction in allogeneic hematopoietic cell transplantation

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT), formerly called bone marrow transplantation, can potentially cure various malignant and non-malignant diseases, but it is associated with a high risk of toxicity. We have previously shown an overall 21% incidence of severe acute renal failure in patients undergoing autologous HCT. The present study evaluated renal dysfunction in patients undergoing allogeneic HCT.

METHODS

The clinical course of 88 adult patients who received allogeneic HCT at the University of Colorado Health Science Center was analyzed. Renal dysfunction was classified as follows: Grade 0 = normal renal function; Grade 1 =>25% decrement in GFR but <twofold rise in serum creatinine; Grade 2 =>twofold increase in serum creatinine; Grade 3 =>twofold increase in serum creatinine and need for dialysis.

RESULTS

Of the 88 patients, 81 (92%) patients had some degree of renal dysfunction (Grade 1, 20 patients; Grade 2, 32 patients; Grade 3, 29 patients). Severe nephrotoxicity (Grade 2 and Grade 3 renal dysfunction) was associated with significantly higher frequencies of sepsis, hepatic toxicity and hepatic veno-occlusive disease (VOD), and lung toxicity. The overall mortality rate at the end of 6 months was 58%. Grade 3 renal dysfunction was associated with a significantly increased risk of mortality (82.6%).

CONCLUSION

A 92% incidence of renal dysfunction in allogeneic HCT patients was found. Lung and liver toxicities were significantly correlated with developing renal dysfunction, and the mortality rates for patients with Grade 3 renal failure exceeded 80%.

Incidence and outcome of cytomegalovirus infections following nonmyeloablative compared with myeloablative allogeneic stem cell transplantation, a matched control study

Nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT) is increasingly being explored as therapy in patients who are not eligible for conventional myeloablative HSCT. Whether these transplants are associated with reduced risk of transplantation-related infections is unknown. We analyzed the incidence of posttransplantation cytomegalovirus (CMV) infections in 56 consecutive mycophenolate mofetil (MMF) patients with hematologic malignancies who underwent nonmyeloablative HSCT (TBI, 2Gy, day 0; MMF/cyclosporine after transplantation). In addition, 18 of 56 patients received 30 mg/m(2)/d fludarabine on days -4 to -2. Most donors were HLA matched and related (93%). Each case patient was matched to 2 controls who were treated by conventional HSCT during the same time period (January 1997 through April 2000). Matching criteria included CMV risk group, HSC source, donor type, age, and underlying diseases. No CMV disease occurred in the low (donor and recipient serologically negative) and intermediate (donor serologically positive and recipient negative) CMV risk groups during the first 100 days. Among cases at high risk for CMV (seropositive recipients), trends to less CMV antigenemia (P =.11), viremia (P =.16), and disease (P =.08) compared with controls were observed; all severe manifestations combined (CMV viremia and disease) were significantly reduced among cases (P =.01). However, by day 365, the overall incidence of CMV disease became similar in both groups. The onset of CMV disease was significantly delayed among case patients compared with controls (median, 130 days versus 52 days; P =.02). It was concluded that CMV disease was significantly delayed in nonmyeloablative cases, but that the overall 1-year incidence was similar to myeloablative HSCT patients. Therefore, nonmyeloablative HSCT patients should receive CMV surveillance beyond day 100 and pre-emptive ganciclovir treatment similar to that of myeloablative HSCT patients.

Nonmyeloablative hematopoietic cell transplantation: status quo and future perspectives

In nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT), high-dose cytotoxic therapy as the conceptual basis for treating hematopoietic malignancies has been replaced by graft-versus-tumor effects. The use of potent pre- and postgrafting immunosuppression derived from preclinical studies has allowed omission of myeloablative cytotoxic therapy without compromising hematopoietic donor cell engraftment. This results in a marked reduction in transplant-related toxicities that makes older or medically infirm patients candidates for this treatment option. This patient group is more representative of the population with cancer and would have been ineligible for conventional HSCT. Initial results in patients with a variety of hematologic malignancies have been encouraging with documented sustained cytogenetic and molecular remissions in a substantial number of sometimes heavily pretreated and previously refractory patients. Even though patients with hematologic malignancies will likely require conversion to full donor hematopoiesis for long-term disease control, a state of mixed hematopoietic chimerism might suffice to "cure" the disease phenotypes in various nonmalignant diseases. Strategies aimed at optimizing peritransplant immunosuppression may eventually eliminate the need for pretransplant total body irradiation, which is relevant for minimizing late toxicities. Enhancing graft-versus-tumor effects by virtue of postgrafting vaccination of recipients against tumor-specific antigens may help to use this transplant approach more effectively in the treatment of solid tumors.

Prognostic model for relapse after high-dose chemotherapy with autologous stem-cell transplantation for stage IV oligometastatic breast cancer

PURPOSE

To study prognostic factors after high-dose chemotherapy (HDC) for patients with stage IV oligometastatic breast cancer.

PATIENTS AND METHODS

Sixty patients with minimal metastatic disease amenable to local therapy enrolled onto a prospective HDC trial were analyzed for potential prognostic factors. Tumor blocks were retrospectively collected from referring institutions.

RESULTS

Median follow-up was 62 months (range, 4 to 120 months). Median relapse-free survival (RFS) and overall survival (OS) times were 52 and 80 months, respectively. Five-year RFS and OS rates were 52% (95% confidence interval [CI], 39% to 64%) and 62% (95% CI, 49% to 74%), respectively. HER-2 expression, number of tumor sites, primary axillary nodal ratio (number of positive nodes divided by number of sampled nodes), number of positive axillary nodes, and delivery or omission of radiotherapy to metastases correlated with RFS. HER-2 overexpression and more than one site were independent adverse risk factors for RFS. HER-2 and the axillary nodal ratio were independent predictors of OS. The following prognostic categories for RFS were established (RFS rate, median RFS): good risk, no factors (77%, 80 months); intermediate risk, one factor (41%, 28 months); and poor risk, both factors (10%, 10 months).

CONCLUSION

Long-term results in patients with oligometastatic breast cancer are encouraging but need validation in prospective randomized studies. HER-2 expression, number of sites, and primary nodal ratio are independent outcome predictors. Confirmation of these observations in this selected population would imply the need for reevaluation of the current tenet that early detection of metastatic breast cancer recurrence is of no benefit.

Intensive chemotherapy for progressive chronic lymphocytic leukemia administered early after a nonmyeloablative allograft

A 51-year-old patient with refractory CLL elected to participate in a trial of nonmyeloablative trans- plantation from an HLA-matched unrelated donor. He received low-dose fludarabine/TBI, with infusion of donor PBPC and cyclosporin (CsA)/MMF. Early post transplant he experienced explosive tumor growth with respiratory insufficiency. After immunosuppression discontinuation and rituximab administration, no response was observed. This prompted treatment with cyclophosphamide (2 g/m(2)/day x 2), paclitaxel (250 mg/m(2) over 24 h), doxorubicin (50 mg/m(2)), solumedrol (500 mg/day), and a second dose of rituximab, from days +11 to +14. A rapid response was achieved. Chemotherapy did not cause an obvious compromise of donor stem cell engraftment or establishment of stable donor chimerism.

Nonmyeloablative hematopoietic stem cell transplantation: transplantation for the 21st century

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy to achieve allogeneic engraftment and control of underlying disease. For engraftment purposes, preclinical studies and clinical observations have shown that conditioning regimens can be markedly reduced in intensity, resulting in reduced treatment toxicities. Preclinical canine studies demonstrated that the use of potent pre- and postgrafting immunosuppression allows for reduction in conditioning regimens while facilitating development of stable mixed chimerism. If attenuated conditioning regimens can be successfully translated to human stem cell transplantation, an improved safety profile will allow potentially curative treatment to a more representative patient profile not currently offered such therapy. Mixed chimerism could prove curative of disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. For patients with hematopoietic malignancy, spontaneous conversion to full donor hematopoeisis after stem cell transplant may prove curative by virtue of graft versus host reactions directed against the malignancy, however infusion of additional donor lymphocytes may be needed to treat persistent disease.