A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067

Planets with radii between that of the Earth and Neptune (hereafter referred to as 'sub-Neptunes') are found in close-in orbits around more than half of all Sun-like stars1,2. However, their composition, formation and evolution remain poorly understood3. The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD 110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R⊕ to 2.85R⊕. Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres.

Homing and Immunogenicity of Murine Stromal Cells Transfected with Xenogeneic Mhc Class II Genes

Syngeneic (murine) and xenogeneic (canine) marrow-derived stromal cells were injected intravenously into SCID and normal mice to examine the homing pattern and persistence of these cells in vivo. By in situ hybridization, these stromal cells were detectable in the bone marrow cavity and the spleen 21 days after injection. Xenogeneic cells did not persist in normal mice but persisted in SCID mice. Conditioning of the recipients with irradiation or S-fluorouracil (5-FU) treatment did not alter these results. In addition, syngeneic murine stromal cells were transfected with the genes for canine MHC class II (DRA + DRB) and transplanted into murine recipients to investigate their homing pattern and immunogenicity. These transfected syngeneic stromal cells did also home to marrow and spleen even in normal recipients. However, these cells led to sensitization of the host towards canine antigens as shown by accelerated skin graft rejection and delayed type hypersensitivity (DTH). Thus, immunodeficient (SCID) mice allow for the homing of xenogeneic stromal cells to hemopoietic organs and for prolonged persistence. In immunocompetent (normal) mice, no xenogeneic stromal cells were identified in spleen and marrow, either because of their inability to home or more likely because of immunological rejection. In contrast, syngeneic stromal cells expressing xenogeneic MHC class II genes did home to spleen and marrow and persisted even though the recipient had become sensitized. Their survival may be due to a loss of expression of the transfected gene. Alternatively, the presentation of these xenogeneic gene products in the hemopoietic organs was such that a cytotoxic response was not induced. These results also show that stromal cells can serve as a vehicle for gene delivery, conceivably with the possibility of organ targeting.

Treatment of refractory ITP and Evans syndrome by haematopoietic cell transplantation: is it indicated, and for whom?

Several lines of therapy have been established for patients with immune thrombocytopenia (ITP) and Evans syndrome. However, these therapies generally require prolonged administration, lead to profound immunosuppression and increased infectious risk, and are often poorly tolerated. While most patients with these disorders will respond to first-line steroid therapy, others will prove refractory or intolerant to multiple treatments. In these patients (and possibly even selected patients who are not considered refractory), autologous or allogeneic haematopoietic stem cell transplantation (HCT) may provide definitive therapy. We review the literature on the treatment of ITP and Evans syndrome with HCT and discuss its use in the management of these disorders. We also pose, for the purpose of discussion, research questions that will be important to address if HCT is to be considered a viable option for more patients with these diseases.

Dissecting graft-versus-leukemia from graft-versus-host-disease using novel strategies

The intrinsic anti-leukemic effect of allogeneic hematopoietic cell transplantation (HCT) is dependent on genetic disparity between donor and recipient, intimately associated with graft-versus-host disease (GVHD), and mediated by lymphocytes contained in or derived from the donor hematopoietic cell graft. Three decades of intense effort have not identified clinical strategies that can reliably separate the graft-versus-leukemia (GVL) effect from the alloimmune reaction that drives clinical GVHD. For patients who require HCT and for whom two or more human leukocyte antigen (HLA)-A, -B, -C, and -DRB1-matched donor candidates can be identified, consideration of donor and recipient genotype at additional genetic loci both within and outside the major histocompatibility complex may offer the possibility of selecting the donor [candidate(s)] that poses the lowest probability of GVHD and the highest probability of a potent GVL effect. Strategies for engineering conventional donor lymphocyte infusion also hold promise for prevention or improved treatment of post-transplant relapse. The brightest prospects for selectively enhancing the anti-leukemic efficacy of allogeneic HCT, however, are likely to be interventions that are designed to enhance specific antitumor immunity via vaccination or adoptive cell transfer, rather than those that attempt to exploit donor alloreactivity against the host. Adoptive transfer of donor-derived T cells genetically modified for tumor-specific reactivity, in particular, has the potential to transform the practice of allogeneic HCT by selectively enhancing antitumor immunity without causing GVHD.

Effect of intravenous coadministration of human stroma cell lines on engraftment of long-term repopulating clonal myelodysplastic syndrome cells in immunodeficient mice

Engraftment of clonal hematopoietic precursor cells from patients with myelodysplastic syndrome (MDS) in immunodeficient mice has been difficult to achieve by intravenous (i.v.) injection. We used i.v. coadministration of the human marrow stroma cell line HS27a with CD34+ MDS cells in Nod.cg-Prkdc^scid Il2rg^tm1wjll (NSG) mice to provide signals that would facilitate engraftment. Hematopoietic cells from 24 MDS patients were transplanted. Cells from all patients were engrafted, and engraftment was documented in 44 of 46 evaluable mice (95%). Immunohistochemistry revealed human HS27a stroma colocalizing with human hematopoietic cells in mouse spleens. Human CD34+ precursors harvested from marrow and spleen of primary murine recipients, when combined with HS27a cells, were also engrafted successfully in secondary NSG recipients, showing persistence of the original clonal characteristics. This observation supports the concept that clonal markers were present in long-term repopulating cells. We suggest that HS27a stroma cells ‘traveled' in direct contact with hematopoietic precursors and enabled their propagation. An essential signal for engraftment appears to be CD146, which is prominently expressed on HS27a cells. This xenotransplantation model will allow to further dissect signals that control engraftment of MDS cells and should be amenable to in vivo treatment studies.

Phenotyping of canine lymphoma with monoclonal antibodies directed at cell surface antigens: Classification, morphology, clinical presentation and response to chemotherapy

Forty cases of naturally occurring canine lymphoma were studied using a panel of murine monoclonal antibodies which identify defined subsets of normal canine lymphocytes. The distribution of phenotypes was similar to that which is seen in man in that the majority (78 per cent) of canine lymphomas were of B-cell origin but a definite minority were phenotypically of T-cell (10 per cent) or non-B, non-T-cell (12 per cent) origin. The expression of Ia-like antigens was restricted to B-cell neoplasms. Within each histologic subgroup of canine lymphomas there was considerable heterogeneity of cell surface marker expression. Immunophenotype appeared to correlate with clinical presentation. Finally, the reactivity of lymphoma cells with murine monoclonal antibody DLy-6, an antibody which appears to react with a differentiation antigen on canine B and T cells, strongly predicted the outcome of initial induction chemotherapy in that all ten evaluable dogs with DLy-6-tumors achieved complete responses to initial chemotherapy while only four of 11 dogs with DLy-6+ tumors responded completely.

Cyclophosphamide-based in vivo T-cell depletion for HLA-haploidentical transplantation in Fanconi anemia

Allogeneic hematopoietic cell transplantation (HCT) is the only known cure for patients with Fanconi anemia (FA) who develop aplasia or leukemia. However, transplant regimens typically contain high-dose alkylators, which are poorly tolerated in FA patients. Furthermore, as many patients lack human leukocyte antigen (HLA)-matched family donors, alternative donors are used, which can increase the risk of both graft rejection and graft-versus-host disease (GVHD). To improve on these three concerns, we developed a multi-institutional clinical trial using a fludarabine (FLU)-based conditioning regimen with limited alkylators/low-dose radiation, HLA-haploidentical marrow, followed by reduced-dose cyclophosphamide (CY) to treat three FA patients with aplasia. All three patients engrafted with 100% donor CD3 chimerism at 1 month. One patient died early from disseminated toxoplasmosis infection. Of the two survivors, one had significant pretransplant co-morbidities and inadequate immunosuppression, and developed severe acute GVHD. The other patient had only mild acute and no chronic GVHD. With a follow-up of 2 and 3 years, respectively, both patients are doing well, are transfusion-independent, and maintain full donor chimerism. The patient with severe GVHD has resolving oral GVHD and good quality of life. We conclude that using low-intensity conditioning, HLA-haploidentical marrow, and reduced-dose CY for in vivo T-cell depletion can correct life-threatening aplasia in FA patients.

Differential effects of bexarotene on intrinsic and extrinsic pathways in TRAIL-induced apoptosis in two myeloid leukemia cell lines

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces programmed cell death (apoptosis) preferentially in tumor cells. However, not all cancer cells are sensitive to TRAIL. We determined whether ligation of the retinoid receptor, RXR, would sensitize cells to TRAIL-mediated apoptosis. The leukemic cell lines KG1a (apoptosis-resistant) and ML-1 (apoptosis-sensitive) were treated with the RXR-specific retinoid bexarotene, TRAIL, or both, and apoptosis was determined. In KG1a cells, bexarotene downregulated FLIP(Long) and activated caspase-8, thereby allowing for TRAIL-triggered apoptosis. Overexpression of FLIP(Long) in ML-1 cells abrogated apoptosis. In unmodified ML-1 cells bexarotene enhanced programmed cell death via truncation of Bid and release of cytochrome C. Blockade of caspase-8 prevented enhancement in both cell lines; blockade of caspase-9 had a significant effect only in ML-1 cells. Thus, the effect of bexarotene on TRAIL-mediated programmed cell death involved proximal events of the extrinsic pathway; however, downstream signals involved the intrinsic pathway in ML-1 but not in KG1a cells. These studies add further information to the regulation of programmed cell death in leukemic cells that have to be considered when designing therapeutic strategies.

Results of donor lymphocyte infusions for relapsed myelodysplastic syndrome after hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) represents a potentially curative approach for patients with myelodysplastic syndromes (MDSs). While a large proportion of HCT recipients become long-term disease-free survivors, recurrence of MDS remains the leading cause of mortality after HCT. The role of donor lymphocyte infusion (DLI) in patients with relapsed MDS after HCT is unclear. We report results among 16 patients treated with DLI for relapsed MDS after HCT at a single institution between March 1993 and February 2004. The cohort contained 10 men and 6 women with a median age of 49 (range, 22-67) years. CR with resolution of cytopenias and prior disease markers occurred in 3 of 14 patients who could be evaluated. Two patients survived without MDS for 68 and 65 months after DLI, respectively, but died with pneumonia. Grades II-IV acute GVHD and chronic GVHD occurred after DLI in 6 (43%) and 5 (36%) patients, respectively. All three responders developed grades III-IV acute GVHD and extensive chronic GVHD after DLI. Our results confirm prior reports that DLI can result in CR in some patients with recurrent MDS after transplant, but long-term survival is infrequent.

Unrelated donor hematopoietic cell transplantation (HCT) as treatment for acute myeloid leukemia (AML) in first remission

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Background: Unrelated donor HCT has been used with increasing frequency for the treatment of AML patients in first remission. Methods: Between 1990 and 2005, 105 adult patients with AML [66 (62%) primary and 39 (38%) secondary] received T- cell-replete HCT from unrelated donors in Seattle. Results: Median age was 44 (range, 18–74) years. Seventy-nine patients received ablative conditioning for HCT (57% conditioned with cyclophosphamide plus total body irradiation (TBI), 43% with chemotherapy alone). Non- myeloablative doses of fludarabine (FLU; 25 mg/m2 daily for 3 days) and TBI (200 cGy) were delivered to 26 patients. Ninety-six percent of patients who underwent reduced-intensity conditioning received unrelated peripheral blood stem cells (PBSC) while 59% of myeloablative HCT patients received PBSC as their source of stem cells. For all patients, the leukemia-free survival (LFS) and non-relapse mortality estimated at 2 years were 53%, and 26%, respectively, as 27 patients died of transplant-related causes (pulmonary-6, cardiac-1, graft versus host disease (GVHD)-6, infection-5, and unknown-9). Twenty-two patients (21%) relapsed 2 to 83 months (median 5) post-transplant, and 56 patients are surviving disease-free 1 to 168 months (median 27) post-transplant. For 90 patients (86%) with intermediate-risk cytogenetics, 51 (57%) are surviving disease-free, with 16 (18%) relapsing. Fourteen patients (13%) were considered high risk based on unfavorable cytogenetics; 4 of these 14 (29%) are surviving disease-free and 6 (43%) have relapsed. The probability of grade 3/4 acute GVHD was 19% while the probability of clinical extensive chronic GVHD was 54% one year after transplant. Unfavorable cytogenetics (HR=2.16, p=.08), secondary leukemia (HR=1.71, p=.10), higher co-morbidity score (p<.0001), and HLA mismatching (HR=2.35, p=.02) were associated with an increased hazard of mortality. After controlling for these factors, non-ablative conditioning was not statistically worse than ablative conditioning (HR=1.21, p=.61). Conclusions: These data suggest that HCT using unrelated allografts has the potential to provide significant LFS for patients undergoing HCT for AML in first remission when an HLA family match is not available.

No significant financial relationships to disclose.

Protection of human and murine hepatocytes against Fas-induced death by transferrin and iron

Recent studies in a murine model show that transferrin (Tf) interferes with Fas-mediated hepatocyte death and liver failure by decreasing pro-apoptotic and increasing anti-apoptotic signals. We show here in vitro in murine and human hepatocyte cell lines and in vivo in mice that Fas-induced apoptosis is modulated by exogenous Tf and iron. The results obtained with iron-free Tf (ApoTf), iron-saturated Tf (FeTf), and the iron chelator salicylaldehyde isonicotinoyl hydrazone (SIH) in its iron-free and iron-saturated (FeSIH) forms indicate that apoptosis-modulating effects of Tf are not mediated by iron alone. Both the Tf molecule and iron affect multiple aspects of cell death, and the route of iron delivery to the cell may be critical for the final outcome of cellular Fas signaling. Survival of hepatocytes 'stressed' by Fas signals can be manipulated by Tf and iron and may be a target for prophylactic and therapeutic interventions.

Myeloablative vs nonmyeloablative allogeneic transplantation for patients with myelodysplastic syndrome or acute myelogenous leukemia with multilineage dysplasia: a retrospective analysis

Transplant outcome was analyzed in 150 patients with myelodysplastic syndrome (MDS) or acute myelogenous leukemia transformed from MDS (tAML) conditioned with nonmyeloablative or myeloablative regimens. A total of 38 patients received nonmyeloablative regimens of 2 Gy total body irradiation alone (n=2) or with fludarabine (n=36), 90mg/m2. A total of 112 patients received a myeloablative regimen of busulfan, 16mg/ kg (targeted to 800-900 ng/ml), and cyclophosphamide 120 mg/ kg. Nonmyeloablative patients were older (median age 62 vs 52 years, P<0.001), more frequently had progressed to tAML (53 vs 31%, P=0.06), had higher risk disease by the International Prognostic Scoring System (53 vs 30%, P=0.004), had higher transplant specific comorbidity indices (68 vs 42%, P=0.01) and more frequently had durable complete responses to induction chemotherapy (58 vs 14%). Three-year overall survival (27%/48% (P=0.56)), progression-free survival (28%/4 44%, (P=0.60)), and nonrelapse mortality (41%/34%, (P=0.94)) did not differ significantly between nonmyeloblative/myeloablative conditioning. Overall (HR=0.9, P=0.84) and progression-free survivals (HR=1, P=0.93) were similar for patients with chemotherapy-induced remissions irrespective of conditioning intensity. Graft vs leukemia effects may be more important than conditioning intensity in preventing progression in patients in chemotherapy-induced remissions at the time of transplantation. Randomized prospective studies are needed to further address the optimal choice of transplant conditioning intensity in myeloid neoplasms.

Optimization of allogeneic transplant conditioning: not the time for dogma

Numerous reduced-intensity conditioning regimens for allogeneic hematopoietic cell transplantation are currently being explored, primarily in older patients and in individuals with comorbid conditions who are not eligible for conventional myeloablative conditioning regimens. There is agreement that these approaches have reduced early transplant-related (non-relapse) toxicity and mortality. It is unclear, however, whether these strategies improve long-term survival. Furthermore, as most trials with reduced-intensity regimens have enrolled older patients and patients with comorbid conditions, it is not appropriate to compare the results of these trials to those obtained with more conventional approaches. It remains to be determined whether younger patients, and patients without comorbid conditions, will derive significant long-term benefits from reduced-intensity regimens when compared to conventional strategies. It may be that the different approaches are complementary and in the end will preferentially serve specific patient populations based on age, comorbid conditions and malignancy type. To determine the role of reduced-intensity approaches, controlled prospective trials are needed, with enrolled patients being stratified according to comorbid conditions, disease characteristics, pre-transplant therapy and source of stem cells, at a minimum.

Low-dose cyclophosphamide conditioning for haematopoietic cell transplantation from HLA-matched related donors in patients with Fanconi anaemia

Allogeneic haematopoietic cell transplantation (HCT) is effective therapy for Fanconi anaemia (FA). FA patients do not tolerate conditioning with 200 mg/kg of cyclophosphamide (Cy), typically used in aplastic anaemia. We previously published results of studies in which Cy doses were gradually reduced from 200 to 100 mg/kg. Here we update results of the initial studies and report data on 30 new patients conditioned with Cy either at 80 mg/kg (n = 7) or at 60 mg/kg (n = 23), given over 4 days before HCT from human leucocyte antigen-matched related donors. Methotrexate and cyclosporine were given for graft-versus-host disease (GVHD) prophylaxis. All seven patients given Cy at 80 mg/kg and 21 of 23 given Cy at 60 mg/kg had sustained engraftment, while two patients, both with clonal cytogenetics abnormalities, experienced graft failure. Grades 2-3 acute GVHD rates were 57% and 14% for patients given the higher and lower Cy doses, respectively (P = 0.001). Four patients given Cy at 80 mg/kg and 22 given Cy at 60 mg/kg were alive at a median of 47 (44-58) months and 16 (3-52) months, respectively. Cy at 60 mg/kg has acceptable toxicities, low rates of GVHD, and is sufficient for engraftment of related grafts in most FA patients.

High IGFBP-3 levels in marrow plasma in early-stage MDS: effects on apoptosis and hemopoiesis

The pathophysiology of the myelodysplastic syndromes (MDS) is incompletely understood. Tumor necrosis factor (TNF)alpha levels are elevated, particularly in early-stage MDS, and apoptosis in marrow cells is upregulated. Observations in other models have shown a role for insulin-like growth factor binding protein 3 (IGFBP-3) in TNFalpha-mediated apoptosis. We observed increased levels of IGFBP-3 in the marrow plasma of patients with MDS (P = 0.005) and hypothesized that altered IGFBP-3 levels contribute to the dysregulation of hemopoiesis in MDS by affecting proliferation and apoptosis. Western analysis of marrow plasma from MDS patients revealed an increase in the ratio of intact vs fragmented IGFBP-3 in early-stage MDS (relative to controls) that decreased with MDS disease progression, suggesting increased proteolysis with more advanced disease. Thus, these results provide evidence for dysregulation of IGFBP-3 in patients with MDS. While the data are complex, they are consistent with a modulatory effect of IGFBP-3 on hemopoiesis in MDS. Conceivably, understanding these mechanisms may allow for the development of novel therapeutic strategies.

Allogeneic bone marrow transplantation in children with myelodysplastic syndrome or juvenile myelomonocytic leukemia: the Seattle experience

The purpose of this study was to evaluate the role of allogeneic bone marrow transplantation (BMT) in children with myelodysplastic syndrome (MDS). In total, 94 consecutive pediatric patients with MDS received an allogeneic BMT from 1976 to 2001 for refractory anemia (RA) (n=25), RA with ringed sideroblasts (RARS) (n=2), RA with excess blasts (RAEB) (n=20), RAEB in transformation (RAEB-T) (n=14), juvenile myelomonocytic leukemia (JMML) (n=32) or chronic myelomonocytic leukemia (CMML) (n=1). The estimated 3-year probabilities of survival, event-free survival (EFS), nonrelapse mortality and relapse were 50, 41, 28 and 29%, respectively. Patients with RA/RARS had an estimated 3-year survival of 74% compared to 68% in those with RAEB and 33% in patients with JMML/CMML. In multivariable analysis, patients with RAEB-T or JMML were 3.9 and 3.7 times more likely to die compared to those with RA/RARS and RAEB (P=0.005 and 0.004, respectively). Patients with RAEB-T were 5.5 times more likely to relapse (P=0.01). The median follow-up among the 43 surviving patients is 10 years (range 1-25). We conclude that allogeneic BMT for children with MDS is well tolerated and can be curative.

[Biologic changes in MDS-L cell line induced by As2O3 and/or TRAIL]

OBJECTIVE

To investigate the biological changes in myelodysplastic syndromes (MDS) myeloid blast cell line MDS-L after different duration and concentration of As2O3/TRAIL (TNF related apoptosis inducing ligand) treatment.

METHODS

MDS-L cells were treated with As2O3 and TRAIL at 9 different concentrations and the treated cells were detected at 24 h, 48 h and 72 h for biologic indexes. The same detections were conducted in untreated MDS-L cells and normal and MDS marrow cells as controls. Apoptosis was assayed by flow cytometry after Annexin V-FITC labelling. Differentiation-induction effect of these drugs on the cells were detected by morphologic examination and CD34(+) proportion analysis after 24 hours treatment and further agar culture for 18 days; P15(ink4b) mRNA expression were detected by RT-PCR and its protein expression by DAB immunocytochemistry, P15(ink4b) DNA methylation by methylation specific PCR (Msp).

RESULTS

As2O3/TRAIL treatment promoted MDS-L cells to undergo apoptosis and As2O3 plus TRAIL showed obvious differentiation-induction effect on MDS-L. P15(ink4b) mRNA expression was upregulated in MDS-L cell line after different drug treatment but almost no protein expression increased. Increased P15 expression seemed to be related with DNA demethylation effect of these drugs.

CONCLUSIONS

As2O3 or/and TRAIL treatment could promote apoptosis of the clonal cells and induce incomplete cell differentiation. The drugs treatment could also increase P15(ink4b) expression in MDS-L cell line through their demethylation effects.

Expression of FLIP(Long) and FLIP(Short) in bone marrow mononuclear and CD34+ cells in patients with myelodysplastic syndrome: correlation with apoptosis

Several apoptosis-inducing systems, including Fas/Fas ligand and TNF-related apoptosis-inducing ligand (TRAIL) and its receptors, are upregulated in myelodysplastic syndrome (MDS). FLIP (FLICE (FAS-associated death-domain-like IL-1beta-converting enzyme)-inhibitory protein)) was identified as an inhibitor of FAS and TRAIL signals. Here, we characterized FLIP(Long) (FLIP(L)) and FLIP(Short) (FLIP(S)) expression in bone marrow mononuclear cells (BMMNCs) and in CD34+ cells of 29 MDS patients, and in 17 normal volunteers. The expression was correlated with apoptotic indices. In CD34+ cells, FLIP(L) levels were higher among normal individuals than in MDS patients (P=0.04). Among total BMMNC, FLIP(L) levels also tended to be higher in normal subjects than in MDS patients, although this difference was not significant (P=0.71). FLIP(L) levels in CD34+ cells were negatively correlated with apoptosis in both normal and MDS marrows (P=0.03). FLIP(Short) RNA expression was higher in MDS patients than in normal controls in both BMMNC (P=0.03) and CD34+ cells (P=0.08). In contrast to FLIP(L), FLIP(St) levels were positively correlated with apoptosis. At the protein level FLIP was most readily detectable in patients with high blast counts. The data suggest that FLIP(L) and FLIP(S) are differentially regulated, and that the relative levels of both isoforms play a role in the regulation of apoptosis in MDS.

Outcome following haematopoietic cell transplantation in patients with myelodysplasia and del (5q) karyotypes

The deletion (5q) karyotype [del (5q)] in patients with myelodysplastic syndrome (MDS) is considered a good risk feature, while the impact of del (5q) combined with other karyotypic abnormalities [del (5q)+] is less well defined. We analysed the outcome of haematopoietic cell transplants (HCT) in patients with MDS with del (5q) or del (5q)+. Fifty-seven patients, aged 6-72 years, with MDS and del (5q) abnormalities received HCT from related (n = 32) or unrelated (n = 25) donors. By French-American-British (FAB) criteria, 27 patients had refractory anaemia (RA), 10 RA with excess blasts (RAEB), eight RAEB in transformation (RAEB-T) and 12 acute myeloid leukaemia evolving from MDS (tAML). Non-relapse mortality at 1-year post-transplantation was 30% for del (5q) and 38% for del (5q)+ patients. Relapse occurred in one of 20 del (5q) patients and 15 of 37 del (5q)+ patients (P = 0.001). After adjusting for del (5q) status, blast count (<5%) was the only factor significantly associated with relapse-free survival. Patients with del (5q), either as a '5q- syndrome' or with MDS in general, had better outcomes than did patients with del (5q)+. The indication for transplantation in patients with del (5q) was generally severe cytopenias, compared with disease progression to a more advanced FAB stage in patients with del (5q)+. Conceivably, outcome for patients with del (5q)+ would be improved with transplantation earlier in the disease course.

Lack of cytoprotective effect of amifostine following HLA-identical sibling transplantation for advanced myelodysplastic syndrome (MDS): a pilot study

The objective of this prospective study was to determine whether amifostine (Ethyol) reduced conditioning-related toxicity following a regimen of busulfan (7 mg/kg) and fractionated total body irradiation (6 x 200 cGy). In all, 12 patients with advanced myelodysplastic syndrome transplanted from HLA-identical siblings were enrolled. Patients received 340 mg/m(2) amifostine i.v. twice daily during conditioning (days -7 through -1). All patients developed oropharyngeal mucositis. Six patients had evidence of sinusoidal obstruction syndrome of the liver. Six patients experienced pulmonary toxicity of grades II-III. A total of 11 patients died, one with relapse and 10 with infectious complications or regimen-related toxicity. Nonrelapse causes of death included invasive aspergillosis in three, multiorgan failure in three, and idiopathic interstitial pneumonitis in two patients. One patient each died of organizing pneumonia and CMV pneumonia. One patient is alive in complete remission 31 months after transplantation. These results were not superior to those in patients conditioned with busulfan plus fractionated total body irradiation and not given amifostine, and suggest that amifostine, as administered here, has no protective effect against toxicity from this myeloablative regimen.

Incidence, risk factors, and mortality from pneumonia developing late after hematopoietic stem cell transplantation

The incidence, etiology, outcome, and risk factors for developing pneumonia late after hematopoietic stem cell transplantation (SCT) were investigated in 1359 patients transplanted in Seattle. A total of 341 patients (25% of the cohort) developed at least one pneumonic episode. No microbial or tissue diagnosis (ie clinical pneumonia) was established in 197 patients (58% of first pneumonia cases). Among the remaining 144 patients, established etiologies included 33 viral (10%), 31 bacterial (9%), 25 idiopathic pneumonia syndrome (IPS, 7%), 20 multiple organisms (6%), 19 fungal (6%), and 16 Pneumocystis carinii pneumonia (PCP) (5%). The overall cumulative incidence of first pneumonia at 4 years after discharge home was 31%. The cumulative incidences of pneumonia according to donor type at 1 and 4 years after discharge home were 13 and 18% (autologous/syngeneic), 22 and 34% (HLA-matched related), and 26 and 39% (mismatched related/unrelated), respectively. Multivariate analysis of factors associated with development of late pneumonia after allografting were increasing patient age (RR 0.5 for <20 years, 1.2 for >40 years, P=0.009), donor HLA-mismatch (RR 1.6 for unrelated/mismatched related, P=0.01), and chronic graft-versus-host disease (GVHD; RR 1.5, P=0.007). Our data suggest that extension of PCP prophylaxis may be beneficial in high-risk autograft recipients. Further study of long-term anti-infective prophylaxis based on patient risk factors after SCT appear warranted.

B-cell lymphoma developing in the donor 9 years after donor-origin acute myeloid leukemia post bone marrow transplantation

Donor-cell leukemia post bone marrow transplantation is a rare event. Most of the cases reported to date have developed in cells from an HLA-matched sibling, who had no evidence of malignant disease before or following the occurrence of donor-origin leukemia. We describe a 17-year-old female who developed B-cell lymphoma 9 years following the occurrence of donor-origin acute myeloid leukemia in her brother for whom she had donated marrow. Cytogenetic analysis of the tumor revealed multiple chromosomal aberrations. The donor was heterozygous for the Ashkenazi mutation of Bloom's syndrome, suggesting that donor-type leukemia could have resulted from genomic instability in the donor cells.

Soluble TNF receptor fusion protein (etanercept) for the treatment of myelodysplastic syndrome: a pilot study

Blockade of tumor necrosis factor (TNF)alpha by a soluble TNF receptor fusion protein (etanercept; Enbrel) improved in vitro hemopoiesis from the marrow of patients with myelodysplastic syndrome (MDS). Therefore, we enrolled 14 MDS patients (4 RA, 2 RARS, 6 RAEB, 2 CMML), 44-80 (median 60) years old, in a pilot trial. Etanercept, 25 mg, was given twice a week s.c. for 16 weeks (increased to three times a week if no response at 8 weeks). Among 12 evaluable patients, four had rises in hemoglobin by 1-1.5 gm/dl (three) or decreased transfusion requirements (one). Two patients had increased platelet counts (54% and 73%), and two increased neutrophils (63% and 120%). Baseline TNFalpha levels, determined in all patients, did not correlate with responses. Among eight marrows available for sequential in vitro assays, four showed increases in CFU-GM of 1.5- to 5-fold at 8 weeks, whereas three showed 3- to 10-fold decrements relative to baseline. Thus, etanercept treatment resulted in moderate improvements of cytopenias in some patients, while cell counts declined in others. Additional trials are needed to evaluate its clinical efficacy in MDS.

Sirolimus (rapamycin) for the treatment of steroid-refractory acute graft-versus-host disease

BACKGROUND

In a pilot trial we evaluated the toxicity and efficacy of sirolimus (rapamycin) as second-line therapy for the treatment of acute graft-versus-host disease (GVHD) in 21 patients (1-46 years of age) after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

All patients were treated with methylprednisolone at 2 mg/kg/day, but failed to respond satisfactorily. Sirolimus was started 19-78 (median 37) days after HSCT when 10 patients had grade III and 11 had grade IV GVHD. The first four patients received a loading dose (15 mg/m2) of oral sirolimus on day 1 followed by 5 mg/m2/day for 13 days. The next 17 patients received either 5 (n=7) or 4 (n=10) mg/m2/day for 14 days without a loading dose. Eleven patients completed the 14-day sirolimus course. Five patients were treated for 9-13 days, two for 6 days, and three for 1-3 days.

RESULTS

Sirolimus was discontinued early in 10 patients because of lack of improvement in GVHD (n=5), myelosuppression (n=2), seizure (n=2), and attending physician preference (n=1). The most common and significant adverse events were thrombocytopenia (n=7) and neutropenia (n=4). Other side effects included increased blood triglycerides (n=8) and cholesterol (n=3). Five patients had evidence of a hemolytic uremic syndrome concurrently with or after sirolimus treatment. Eighteen of the 21 patients received 6 or more doses of sirolimus and 12 responded, 5 with complete and 7 with partial responses. Six of the 12 responders (28% of all patients enrolled) and 1 nonresponder are currently alive at 400-907 days after HSCT, 3 with chronic GVHD. Fourteen of the 21 patients (66%) died 40-263 days after transplant.

CONCLUSION

These data suggest that sirolimus has activity in the treatment of steroid-refractory acute GVHD. However, there was considerable toxicity and further dose optimization studies seem warranted.

Busulfan plus cyclophosphamide compared with total-body irradiation plus cyclophosphamide before marrow transplantation for myeloid leukemia: long-term follow-up of 4 randomized studies

In the early 1990s, 4 randomized studies compared conditioning regimens before transplantation for leukemia with either cyclophosphamide (CY) and total-body irradiation (TBI), or busulfan (Bu) and CY. This study analyzed the long-term outcomes for 316 patients with chronic myeloid leukemia (CML) and 172 patients with acute myeloid leukemia (AML) who participated in these 4 trials, now with a mean follow-up of more than 7 years. Among patients with CML, no statistically significant difference in survival or disease-free survival emerged from testing the 2 regimens. The projected 10-year survival estimates were 65% and 63% with Bu-CY versus CY-TBI, respectively. Among patients with AML, the projected 10-year survival estimates were 51% and 63% (95% CI, 52%-74%) with Bu-CY versus CY-TBI, respectively. At last follow-up, most surviving patients had unimpaired health and had returned to work, regardless of the conditioning regimen. Late complications were analyzed after adjustment for patient age and for acute and chronic graft-versus-host disease (GVHD). CML patients who received CY-TBI had an increased risk of cataract formation, and patients treated with Bu-CY had an increased risk of irreversible alopecia. Chronic GVHD was the primary risk factor for late pulmonary disease and avascular osteonecrosis. Thus, Bu-CY and CY-TBI provided similar probabilities of cure for patients with CML. In patients with AML, a nonsignificant 10% lower survival rate was observed after Bu-CY. Late complications occurred equally after both conditioning regimens (except for increased risk of cataract after CY-TBI and of alopecia with Bu-CY).

Administration of cyclosporine for 24 months compared with 6 months for prevention of chronic graft-versus-host disease: a prospective randomized clinical trial

This study compared the incidence of clinical extensive chronic graft-versus-host disease (GVHD), transplantation-related mortality, survival, and relapse-free survival among recipients randomly assigned to receive a 24-month or a 6-month course of cyclosporine prophylaxis after transplantation of allogeneic marrow from an HLA-identical sibling or alternative donor. Patients who did not have clinical manifestations of chronic GVHD on day 80 after transplantation were eligible for the study if they previously had acute GVHD or if a skin biopsy showed histologic evidence of chronic GVHD. Clinical extensive chronic GVHD developed in 35 of the 89 patients (39%) in the 24-month group and 37 of the 73 patients (51%) in the 6-month group. The hazard of developing chronic GVHD was not significantly different in the 2 groups (hazard ratio = 0.76; 95% confidence interval, 0.48-1.21; P =.25). In addition, there were no significant differences between the 2 groups in transplantation-related mortality, survival, or disease-free survival.

Expression of tumor necrosis factor-related apoptosis-inducing ligand, Apo2L, and its receptors in myelodysplastic syndrome: effects on in vitro hemopoiesis

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor (TNF) family, binds to several cell-surface receptors with distinct functions (agonistic receptors 1 and 2 [TRAIL-R1, TRAIL-R2]; decoy receptors 3 and 4 [TRAIL-R3, TRAIL-R4]). Expression and function was characterized in patients with myelodysplastic syndromes (MDSs). While normal marrow showed negligible expression of TRAIL and receptors (except TRAIL-R3), TRAIL and all receptors were constitutively expressed in MDS marrow. Following TRAIL exposure, MDS marrow showed significant increases in apoptosis, whereas normal marrow, except for a subset of CD34+ precursors, did not (P =.012). Marrow from 21 patients with MDS was then propagated in long-term cultures in the presence or absence of TRAIL. While in advanced MDS (refractory anemia with excess blasts in transformation [RAEB-T] and tAML [MDS transformed into AML]), colony numbers decreased in the presence of TRAIL (63.0% +/- 10.4% of untreated group [100%]), numbers increased in patients with RA or RAEB (160.2% +/- 90.5% of untreated group). TRAIL eliminated preferentially clonally abnormal cells as identified by chromosomal markers. Thus, TRAIL and receptor expression differed significantly between normal and MDS marrow, and TRAIL modulated in vitro hemopoiesis in MDS dependent upon disease stage but not, to a detectable extent, in normal marrow.

Treatment of steroid-refractory acute graft-versus-host disease with anti-CD147 monoclonal antibody ABX-CBL

ABX-CBL, an immunoglobulin M murine monoclonal antibody, recognizes CD147 and initiates cell killing through complement-mediated lysis. In a dose-finding trial, 27 patients with steroid-refractory acute graft-versus-host disease (GVHD) received ABX-CBL at 0.01 (presumed no effect dose), 0.1, 0.2, or 0.3 mg/kg per day, and an additional 32 patients were given ABX-CBL at 0.2 or 0.15 mg/kg per day. All patients had undergone allogeneic transplantation for malignant or nonmalignant disorders and received GVHD prophylaxis, generally with methotrexate- and cyclosporine-containing regimens. None responded to methylprednisolone, given for a minimum of 3 days. ABX-CBL was started 20 to 236 (median, 47) days after transplantation; it was given for 7 consecutive days and was followed by 2 infusions per week for 2 more weeks. Among 51 patients evaluable for efficacy, 26 (51%) responded, including 13 with complete responses (CR) and 13 with partial responses (PR). CR lasting 14 days or longer or PR lasting 7 days or longer occurred in 21 (41%; 8 CR, 13 PR) patients, including 19 of 43 (44%) patients who received 0.1 to 0.3 mg/kg ABX-CBL and 2 of 8 (25%) patients given 0.01 mg/kg per day. Myalgias at doses 0.2 mg/kg or greater were dose limiting and resolved without sequelae. Causes of death included organ failure, progressive GVHD, and infection. No death was attributed to ABX-CBL. At 6 months after the initiation of ABX-CBL therapy, 26 (44%) patients were surviving. These results are encouraging. Further studies on the use of ABX-CBL in the management of GVHD are warranted.

Intravenous busulphan for conditioning before autologous or allogeneic human blood stem cell transplantation

This study was undertaken to evaluate the toxicity and pharmacokinetics of a dimethyl sulphoxide (DMSO)-based intravenous formulation of busulphan in the conditioning of 45 patients undergoing allogeneic or autologous stem cell transplantation (SCT). Busulphan was given as a single daily dose. In 15 patients a single dose of intravenous busulphan, given over 3 h in 1 d, was combined with additional oral (single daily) doses. Thirty patients received all four daily doses intravenously. Busulphan plasma levels were analysed using high performance liquid chromatography. There was no major acute toxicity with daily intravenous doses of 2.8-3.1 mg/kg infused over 3 h. No veno-occlusive disease (VOD) was seen in 30 patients receiving busulphan as an intravenous formulation over 4 d. In the group of 15 patients receiving three oral doses and one intravenous single daily dose, one patient experienced mild VOD. Pharmacokinetic samples were taken over at least 2 d of treatment in 44 patients. The area under the concentration time curve (AUC) values normalized for a dose of 1 mg/kg were 7000 ng/ml x h on d 1 and 5890 ng/ml x h on d 4, thus showing a moderate decrease over time. This was accompanied by a moderate increase of the clearance from 2.6 to 3.0 ml/min/kg. Administration of busulphan as a DMSO-based intravenous formulation was well tolerated. The total dose of busulphan can be given in four (rather than the typical 16) doses. With such a regimen, the intravenous administration becomes feasible on an outpatient basis.

Absence of major histocompatibility class II expression does not impair hematopoiesis in mice

OBJECTIVE

Major histocompatibility class II (MHC II) molecules are among the earliest antigens to be expressed in hematopoietic progenitor cells; however, the functional role of these molecules in hematopoiesis remains controversial. We examined the role of MHC II antigens during hematopoiesis using a mouse model of MHC II deficiency related to the absence of the critical transcriptional activator, CIITA.

METHODS

Sca-1(-), Sca-1(+)lin(+), and Sca-1(+)lin(-) populations of marrow cells from CIITA(-)(/-) and wild-type mice were analyzed by immunofluorescence for MHC II expression. Hematopoietic capacity was assessed in CIITA(-/-) and wild-type mice by CFU-S, CFU-GM, and radiation sensitivity assays.

RESULTS

Flow cytometric characteristics of hematopoietic progenitors from CIITA(-/-) and wild-type mice were identical except for the absence of MHC II expression in CIITA null mice. There were no significant differences in capacity for hematopoietic reconstitution and clonogenicity as measured by radiation sensitivity, CFU-S, and CFU-GM assays among CIITA(-/-) and wild-type mice.

CONCLUSIONS

These experiments show that downregulation of MHC II gene transcription does not effectively alter normal hematopoiesis, and provide strong evidence that MHC II expression on hematopoietic progenitors is not required for normal hematopoietic development.

Myeloablation and autologous peripheral blood stem cell rescue results in hematologic and clinical responses in patients with myeloid metaplasia with myelofibrosis

Current therapeutic options for myeloid metaplasia with myelofibrosis (MMM) are limited. A pilot study was conducted of autologous peripheral blood stem cell (PBSC) collection in 27, followed by transplantation in 21 patients with MMM. The median age was 59 (range 45-75) years. PBSCs were mobilized at steady state (n = 2), after granulocyte colony-stimulating factor (G-CSF) alone (n = 17), or after anthracycline-cytarabine induction plus G-CSF (n = 8). A median of 11.6 x 10(6) (range 0 to 410 x 10(6)) CD34(+) cells per kilogram were collected. Twenty-one patients then underwent myeloablation with oral busulfan (16 mg/kg) and PBSC transplantation. The median times to neutrophil and platelet recovery after transplantation were 21 (range 10-96) and 21 (range, 13 to > or = 246) days, respectively. Five patients received back-up PBSC infusion because of delayed neutrophil or platelet recovery. The median follow-up is 390 (range 70-1623) days after transplantation, and the 2-year actuarial survival is 61%. After transplantion, 6 patients died: 3 of nonrelapse causes (1 within 100 days of PBSC infusion) and 3 of disease progression. Erythroid response (hemoglobin > or = 100 g/L [10 gm/dL] without transfusion for > or = 8 weeks) occurred in 10 of 17 anemic patients. Four of 8 patients with a platelet count less than 100 x 10(9)/L (100 000/microL) responded with a durable platelet count more than 100 x 10(9)/L (100 000/microL). Symptomatic splenomegaly improved in 7 of 10 patients. It is concluded that (1) PBSC collection was feasible and stable engraftment occurred after transplantation in most patients with MMM, (2) myeloablation with busulfan was associated with acceptable toxicity, (3) a significant proportion of patients derived clinical benefit after treatment, and (4) further investigation of this novel approach is warranted. (Blood. 2001;98:586-593)

Cytokines in graft-versus-host disease and the graft-versus-leukemia reaction

Graft-versus-host disease (GVHD) is the major complication after allogeneic hemopoietic stem cell transplantation. GVHD is destructive by itself and sets the stage for other sequelae, in particular, overwhelming infections. Recent investigations have improved our understanding of the underlying pathophysiology of GVHD. There are now compelling data on the role of host tissue destruction as the initial insult, extensive interactions of cellular donor and host components, a complex network of cytokines, adhesion molecules, and other components in the development of GVHD. The improved understanding of interactions among various signals is likely to allow for the development of new prophylactic strategies. A review of the data shows, however, that results are very dependent upon the models used. It is difficult or impossible to separate completely the discussion of cytokines that affect hemopoietic cells from discussion of cytokines that exert effects on immune cells. Furthermore, secondary effects on immune cells via hemopoietic cells complicate the picture. Application of the principles of cytokine signaling to the clinical setting may necessitate new trial design structures that take into consideration donor and host characteristics as well as the kinetics of GVHD development.

Cyclophosphamide and antithymocyte globulin to condition patients with aplastic anemia for allogeneic marrow transplantations: the experience in four centers

This report summarizes the experience with a conditioning regimen of cyclophosphamide and antithymocyte globulin in patients with severe aplastic anemia given HLA-matched related marrow grafts at 4 transplantation centers. Enrolled were 94 consecutive patients, of whom 87 had received multiple transfusions and 38 had failed immunosuppressive therapy. Their ages ranged from 2 to 59 years. After transplantation, 89 patients received a methotrexate/cyclosporine regimen for graft-versus-host disease (GVHD) prevention. Cyclosporine with or without prednisone was given in 4 patients, and no immunosuppression was given in 1 patient. Ninety-six percent of patients had sustained grafts, whereas 4% rejected grafts between 2 and 7 months after transplantation. Of the 4 rejecting patients, 3 are alive with successful second engraftments. Acute grade II GVHD was seen in 21% of patients, grade III in 7%, and grade IV in 1% of patients. Chronic GVHD was seen in 32% of patients, most of whom responded completely to immunosuppressive therapy. With a median follow-up of 6.0 years (range, 0.5-11.6 years), the survival rate was 88%. No unusual long-term side effects have been seen with the regimen. We conclude that the cyclophosphamide/antithymocyte globulin regimen combined with methotrexate/cyclosporine after transplantation is well tolerated and effective in heavily pretreated patients with aplastic anemia.

Hematopoietic stem-cell transplantation for treatment-related leukemia or myelodysplasia

PURPOSE

This report describes results of related or unrelated hematopoietic stem-cell transplants in 111 patients with treatment-related leukemia or myelodysplasia performed consecutively at the Fred Hutchinson Cancer Research Center between December 1971 and June 1998, and identifies patient and treatment characteristics associated with survival and relapse.

PATIENTS AND METHODS

At transplantation, 56 patients had treatment-related secondary acute myeloid leukemia (AML), 15 had refractory anemia with excess blasts in transition (RAEB-T), 23 had refractory anemia with excess blasts (RAEB), 15 had refractory anemia (RA), and two had refractory anemia with ringed sideroblasts (RARS). Conditioning regimens were total-body irradiation (TBI) and chemotherapy for 60 patients, busulfan (BU) 14 to 16 mg/kg and cyclophosphamide (CY) 120 mg/kg (BUCY) for 27 patients, BU targeted to 600 to 900 ng/mL plasma steady-state concentration with 120 mg/kg CY (BUCY-t) for 22 patients, and miscellaneous chemotherapy for two patients. The donors were HLA-identical or partially identical family members for 69 patients and unrelated donors for 42 patients.

RESULTS

The 5-year disease-free survival was 8% for TBI, 19% for BUCY, and 30% for BUCY-t (P =.006). The 5-year cumulative incidence of relapse was 40% for secondary AML, 40% for RAEB-T, 26% for RAEB, and 0% for RA or RARS (P =.0009). The 5-year cumulative incidence of nonrelapse mortality after TBI was 58%; after BUCY, 52%; and after BUCY-t, 42% (P =.02).

CONCLUSION

Patients at risk for treatment-related leukemia or myelodysplasia should be followed closely and be considered for stem-cell transplantation early in the course of myelodysplasia using conditioning regimens such as BUCY-t designed to reduce nonrelapse mortality.

Pro-apoptotic and anti-apoptotic effects of transferrin and transferrin-derived glycans on hematopoietic cells and lymphocytes

The aim of this study was to test the hypothesis that transferrin (Tf) has anti-apoptotic properties and thereby exerts a cytoprotective effect against tissue damage induced by irradiation and other cytotoxic modalities. This hypothesis was tested in several models, including in vitro human short-term marrow cultures, subpopulations of marrow cells, particularly, CD56(+) natural killer cells (and natural killer cell lines), and in vivo radioprotection of murine marrow cells. Reverse transcriptase polymerase chain reaction analysis was used for determination of cytokine mRNA. Preincubation of human marrow with Tf protected cells (except for a CD56(+) subpopulation) against cell death induced by gamma-irradiation, tumor necrosis factor-alpha (TNF-alpha), and agonistic anti-Fas monoclonal antibody. Deglycosylation of Tf abrogated this action of Tf; conversely, Tf-derived glycans (Tf-Gly) (but not glycans isolated from other proteins) mimicked the effects of the intact Tf molecule on apoptosis. Antibodies specific for the Tf receptor (CD71) did not block the effects of Tf or Tf-Gly on apoptosis. Determination of cytokine mRNA in the course of Fas-mediated apoptosis in the presence of Tf or Tf-Gly showed upregulation of mRNA for Fas ligand and TNF-alpha in CD56(+) and downregulation of these transcripts along with upregulation of mRNA for interleukin-10 in CD3(+) marrow cells. Under these conditions, a distinct increase in Fas-associated phosphatase-1 message was observed in CD3(+) cells that were protected by Tf or Tf-Gly against apoptosis. The in vitro data were confirmed in a murine in vivo model in which pretreatment of mice with Tf protected marrow cells against gamma-irradiation-induced cell death. These data suggest a role for Tf and particularly Tf-Gly in the regulation of programmed cell death, apparently via alterations in cytokine expression, and provide a basis for additional studies on the use of Tf in cytoprotective protocols.

Marrow transplants from unrelated donors for patients with aplastic anemia: Minimum effective dose of total body irradiation

Patients with aplastic anemia who do not have suitably HLA-matched, related donors generally receive immunosuppressive treatment as first-line therapy and are considered for transplantation from an unrelated donor only if they fail to respond to immunosuppressive treatment. In this setting, rates of transplantation-related morbidity and mortality have been high. We conducted a prospective study to determine the minimal dose of total body irradiation (TBI) sufficient to achieve sustained engraftment when it is used in combination with 3 cycles of 30 mg/kg of antithymocyte globulin (ATG) and 4 cycles of 50 mg/kg of cyclophosphamide (CY). We also wanted to determine the tolerability and toxicity of the regimen. The starting dosage of TBI was 3 x 200 cGy given over 2 days following CY/ATG. The TBI dose was to be escalated in increments of 200 cGy if graft failure occurred in the absence of prohibitive toxicity, and de-escalated for toxicity in the absence of graft failure. Twenty-one female and 29 male patients aged 1.3 to 46.5 years (median age, 14.4 years) underwent transplantation at 14 medical centers. The time interval from diagnosis to transplantation was 2.8 to 264 months (median, 14.5 months). All patients had been transfused multiple times and all had received 1 to 11 courses (median, 4 courses) of immunosuppressive treatment and other modalities of treatment. In 38 cases, the donors were HLA-A, -B and -DR phenotypically matched with the patients, and, in 12 cases, the donor phenotype differed from that of the recipient by 1 HLA antigen. Recipients of mismatched transplants were considered separately for TBI dose modification, and this study is still ongoing. Seven patients did not tolerate ATG and were prepared with 6 x 200 cGy of TBI plus 120 mg/kg of CY. Of the HLA-matched recipients prepared with CY/ATG/TBI, all 20 who received 3 x 200 or 2 x 200 cGy of TBI achieved engraftment, and 10 are alive. Of the 13 patients who received 1 x 200 cGy of TBI, 1 failed to engraft, and 8 are alive. Each of 10 patients who received an HLA-nonidentical transplant achieved engraftment, and 3 of 6 who were given 3 x 200 cGy of TBI, and 4 of 4 who were given 2 x 200 cGy are alive. Pulmonary toxicity occurred in 8 of 30 patients who were given 3 x 200 or 2 x 200 cGy of TBI concurrently with ATG and CY at 200 mg/kg, and in 2 of 13 patients who received 1 x 200 cGy of TBI, a pattern that suggests a decrease in toxicity with TBI dose de-escalation. Overall, the highest probability of survival (73%) was observed among patients who underwent transplantation within 1 year of diagnosis, compared with patients who underwent transplantation after a longer period of disease. In addition, younger patients (aged < or = 20 years) were more likely to survive than older patients (aged > 20 years). Thus, for patients with an HLA-matched, unrelated donor, a TBI dose of 200 cGy (in combination with CY/ATG) was sufficient to allow for engraftment without inducing prohibitive toxicity. As in previous studies, patient age and pretransplantation disease duration remain important prognostic factors.

Pros and cons of splenectomy in patients with myelofibrosis undergoing stem cell transplantation

During fetal development, the spleen is a major hemopoietic organ. In the adult human, this task is relinquished to the bone marrow. However, under the stress of certain pathologic conditions, extramedullary hemopoiesis may again occur in the spleen. This is especially true for diseases of the marrow, in particular, myeloproliferative disorders such as agnogenic myeloid metaplasia, which is associated with severe fibrosis of the marrow space. At the same time, the spleen sequesters blood cells and contributes to peripheral blood cytopenias, which may improve following splenectomy. However, success is unpredictable, and the operative mortality of splenectomy is on the order of 10%. As a growing number of patients undergo hemopoietic stem cell transplantation as definitive therapy for myelofibrosis, the decision on splenectomy has additional ramifications since the spleen plays an important role in the kinetics of engraftment of donor cells and in immune reconstitution. We conclude from our analysis of available information that the benefit of splenectomy is difficult to predict, although after transplantation splenectomized patients have faster hemopoietic recovery. It appears that the most important indication for splenectomy in these patients is the relief of symptoms from massive spleen enlargement.

Thalidomide for treatment of patients with chronic graft-versus-host disease

In a randomized, placebo-controlled, double-blind trial, thalidomide or placebo together with glucocorticoids and either cyclosporine or tacrolimus was administered as initial therapy for clinical extensive chronic graft-versus-host disease (cGVHD). All patients had thrombocytopenia or cGVHD that evolved directly from acute GVHD as an indicator of a poor prognosis. The study drug (thalidomide or placebo) was administered initially at a dose of 200 mg orally per day, followed by a gradual increase to 800 mg/d if side effects were tolerable. Treatment with the study drug was discontinued before resolution of cGVHD in 23 (92%) of the 25 patients who received thalidomide and in 17 (65%) of the 26 patients who received placebo (P =.02). Neutropenia and neurologic symptoms were the most frequent reasons for early discontinuation of treatment with thalidomide. The duration of treatment with thalidomide was too short to assess its efficacy in controlling cGVHD. (Blood. 2000;96:3995-3996)

Clinical outcome after conversion to FK 506 (tacrolimus) therapy for acute graft-versus-host disease resistant to cyclosporine or for cyclosporine-associated toxicities

This retrospective study describes the outcome in 53 patients who had immunosuppressive treatment changed from cyclosporine (CSP) to tacrolimus for resistant acute GVHD (n = 23), hemolytic uremic syndrome (HUS) (n = 13) or CSP-associated neurotoxicity (n = 17). Tacrolimus was administered at doses of 0.03 mg/kg/day intravenously or 0.12 mg/kg/day orally in divided doses, as tolerated. Median time of conversion to tacrolimus after transplant was day 47. Nineteen patients had treatment changed to tacrolimus for resistant acute GVHD grades III or IV, with the median day of conversion being day 49 after transplant. Two of 20 evaluable patients had a complete resolution of GVHD after changing treatment to tacrolimus, with 18 showing no improvement. Eleven evaluable patients had therapy changed to tacrolimus for CSP-associated neurotoxicity at a median of 36 days after transplant. Eight patients had resolution of neurotoxicity and three had partial improvement. Eleven evaluable patients had therapy changed to tacrolimus for HUS at a median of 46 days after transplant. One patient had complete resolution of HUS and 10 showed no response. Side-effects related to tacrolimus included renal toxicity (34%), neurotoxicity (15%) and HUS (9%). Nine (17%) patients remain alive, including six patients who had therapy changed to tacrolimus for CSP-associated neurotoxicity. While often successful for dealing with neurotoxicity, only a rare patient improved after therapy was changed from CSP to tacrolimus for HUS or resistant acute GVHD.

Hematopoietic stem cell transplantation in patients with myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a stem cell disorder, and hematopoietic stem cell transplantation is currently the only therapeutic modality that is potentially curative. Among patients with less advanced MDS (<5% marrow blasts), 3-year survivals of 65-70% are achievable with HLA-identical related and HLA-matched unrelated donors. The overall probability of disease recurrence in these patients is <5%. Among patients with advanced disease (>/=5% marrow blasts), about 35-45% and 25-30%, respectively, are surviving in remission after transplantation from a related or from an unrelated donor; the incidence of post-transplant relapse is 10-35%. The criteria proposed by the International Prognostic Scoring System (IPSS) derived from non-transplanted patients, also predict survival following transplantation. The development of new conditioning regimens has permitted successful hematopoietic stem cell transplants even in patients more than 60 years of age. Improved survival with transplants from unrelated volunteer donors may, in part, reflect selection of donors on the basis of high resolution (allele-level) HLA typing. Autologous stem cell transplantation may be beneficial for selected patients who have obtained a complete remission with conventional chemotherapy. Treatment-related morbidity and mortality, in particular after allogeneic transplantation, remain challenges that need to be addressed with innovative approaches.

Treatment of chronic myelomonocytic leukaemia by allogeneic marrow transplantation

We evaluated the outcome of allogeneic bone marrow transplantation (BMT) in 21 patients with chronic myelomonocytic leukaemia (CMML) who were treated at the Fred Hutchinson Cancer Research Center between 1990 and 1998. There were 11 male and 10 female patients with a median age of 47.4 years (range 1.0-62.9). Patients were conditioned either with total body irradiation (TBI) and chemotherapy, with or without antithymocyte globulin (n = 19), or with chemotherapy alone (n = 2). The marrow donor was an HLA-identical sibling in 12 patients, an HLA-non-identical related donor in three patients and an unrelated volunteer donor in six patients. All evaluable patients achieved sustained engraftment. Fifteen patients developed grades II-IV acute graft-versus-host disease (GVHD). Nine patients (43.0%) are surviving disease free at 0.7-8.1 years (median 6.9) after transplantation. Five patients relapsed 75-660 d after transplant and all died. Five patients died with organ failure and two died with GVHD and associated infections. The Kaplan-Meier estimates of disease-free survival and relapse at 3 years were 39% and 25% respectively. The probability of survival was improved in patients with shorter disease duration compared with those with a long interval from diagnosis to BMT. Thus, as with other myeloproliferative diseases or myelodysplastic syndromes, BMT offers curative therapy for a proportion of patients with CMML. We suggest that patients with CMML who have a suitable donor should be considered for transplantation, probably early in their disease course. However, it will be important to develop new regimens with enhanced antileukaemic efficacy without further increasing regimen-related toxicity and mortality.

Upregulation of interleukin-10 and inhibition of alloantigen responses by transferrin and transferrin-derived glycans

Previous studies have shown that critically timed administration of transferrin (Tf) facilitates induction of immunologic unresponsiveness. Here, we determined in mixed leukocyte culture (MLC) and in concanavalin A (ConA)-driven cultures the effect of exogenous Tf and Tf-derived glycans (Tf-Gly) on lymphocyte proliferation. In cultures of human blood lymphocytes, Tf inhibited selectively alloantigen-driven proliferation in MLC, but not ConA-stimulated lymphocyte proliferation. Deglycosylation of Tf abrogated the inhibitory effect of Tf on alloantigen-induced lymphocyte proliferation, and, consistent with a role for glycans, an effect qualitatively and quantitatively similar to Tf was exerted by purified Tf-Gly. Glycans isolated from other proteins, for example, immunoglobulin G (IgG) or fibrinogen, failed to inhibit alloantigen-induced proliferation selectively. Rather, they suppressed lymphocyte proliferation in a non-specific manner. Determination of cytokines in MLC supernatant showed a downregulation of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-2, and IL-12 (p40), along with an upregulation of IL-10, a pattern entirely consistent with the observed effects of Tf and Tf-Gly on alloantigen-induced lymphocyte proliferation. The effect of Tf on MLC was directly IL-10-dependent. IL-10 levels were inversely correlated with lymphocyte proliferation and CD86 expression. Neutralization of IL-10 by anti-IL-10 monoclonal antibody (mAb) blocked the effect of Tf. The MLC-modulating effect of Tf (or Tf-Gly) was not dependent upon the Tf receptor CD71 but appeared to be mediated by a Gly-responsive receptor. These data suggest a role of Tf, and, in particular, Tf-Gly, in allo-interactions that is independent from the role of Tf in iron metabolism, and appears to involve co-stimulatory signals.