Myeloablation Followed by Hematopoietic Stem Cell Transplantation and Long-Term Normalization of Systemic Sclerosis Molecular Signatures

OBJECTIVE

In the randomized Scleroderma: Cyclophosphamide or Transplantation (SCOT) trial, myeloablation, followed by hematopoietic stem cell transplantation (HSCT), led to the normalization of systemic sclerosis (SSc) peripheral blood cell (PBC) gene expression signature at the 26-month visit. Herein, we examined long-term molecular changes ensuing 54 months after randomization for individuals receiving an HSCT or 12 months of intravenous cyclophosphamide (CYC).

METHODS

Global PBC transcript studies were performed in study participants at pretreatment baseline and at 38 months and 54 months after randomization, as well as in healthy controls using Illumina HT-12 arrays.

RESULTS

Thirty (HSCT = 19 and CYC = 11) participants had 38-month samples available, and 26 (HSCT = 16 and CYC = 11) had 54-month samples available. In the paired comparison to baseline, a significant down-regulation of interferon modules and an up-regulation of cytotoxic/natural killer module were observed at the 38-month and 54-month visits in the HSCT arm, indicating a long-term normalization of baseline SSc gene expression signature. No differentially expressed modules were detected in the CYC arm. In comparison to samples from healthy controls, 38-month visit samples in the HSCT arm showed an up-regulation of B cell and plasmablast modules and a down-regulation of myeloid and inflammation modules. Importantly, 54-month HSCT samples did not show any differentially expressed modules compared to healthy control samples, suggesting completion of immune reconstitution. Participants in the CYC arm continued to show an SSc transcript signature in comparison to controls at both time points.

CONCLUSION

Paralleling the observed clinical benefit, HSCT leads to durable long-term normalization of the molecular signature in SSc, with completion of immune resetting to 54 months after HSCT.

Remission of severe myasthenia gravis after autologous stem cell transplantation

OBJECTIVE

Myasthenia gravis (MG) is an autoantibody-mediated neuromuscular junction disorder involving the acetylcholine receptors on the motor endplate. The safety and response to high-dose chemotherapy (HDIT) and autologous hematopoietic cell transplantation (HCT) were assessed in a patient with severe refractory MG.

METHODS

As part of a pilot study of HDIT/HCT for patients with treatment-resistant autoimmune neurological disorders, a patient with severe refractory MG underwent treatment. After mobilization of hematopoietic stem cells with rituximab, prednisone, and G-CSF, the patient had HDIT consisting of carmustine, etoposide, cytarabine, melphalan, and rabbit antithymocyte globulin, followed by autologous HCT. The effect of treatment on the autoantibody to the acetylcholine receptor (AChR) was assessed.

RESULTS

The patient had been diagnosed with AChR antibody-positive MG 14 years before HDIT/HCT and had failed thymectomy, therapeutic plasma exchange, and multiple immunomodulatory agents. The Myasthenia Gravis Foundation of America (MGFA) clinical classification was IVb before HDIT/HCT. She tolerated HDIT/HCT well and started to improve clinically within days of treatment. At both 1 and 2 years after HDIT/HCT, patients remained symptom-free. After HDIT/HCT, AChR-binding autoantibodies persisted, and the relative frequency of immune cell subtypes shifted.

INTERPRETATION

HDIT/HCT induced a complete response of disease activity in a patient with severe refractory MG. This response may suggest that a cell-mediated etiology may be a significant contributing factor in refractory MG cases. A phase 2 clinical trial is warranted to establish if HDIT/HCT can be an effective therapy for severe refractory MG and to gain a further understanding of disease pathogenesis.

Myeloablative autologous haematopoietic stem cell transplantation resets the B cell repertoire to a more naïve state in patients with systemic sclerosis

OBJECTIVES

Myeloablative autologous haematopoietic stem cell transplant (HSCT) was recently demonstrated to provide significant benefit over cyclophosphamide (CYC) in the treatment of diffuse cutaneous systemic sclerosis (dcSSc) in the Scleroderma: Cyclophosphamide or Transplantation (SCOT) trial. As dysregulation of the B cell compartment has previously been described in dcSSc, we sought to gain insight into the effects of myeloablative autologous HSCT as compared with CYC.

METHODS

We sequenced the peripheral blood immunoglobulin heavy chain (IGH) repertoires in patients with dcSSc enrolled in the SCOT trial.

RESULTS

Myeloablative autologous HSCT was associated with a sustained increase in IgM isotype antibodies bearing a low mutation rate. Clonal expression was reduced in IGH repertoires following myeloablative autologous HSCT. Additionally, we identified a underusage of immunoglobulin heavy chain V gene 5-51 in patients with dcSSc, and usage normalised following myeloablative autologous HSCT but not CYC treatment.

CONCLUSIONS

Together, these findings suggest that myeloablative autologous HSCT resets the IGH repertoire to a more naïve state characterised by IgM-expressing B cells, providing a possible mechanism for the elimination of pathogenic B cells that may contribute to the benefit of HSCT over CYC in the treatment of dcSSc.

Characterising the autoantibody repertoire in systemic sclerosis following myeloablative haematopoietic stem cell transplantation

OBJECTIVES

Results from the SCOT (Scleroderma: Cyclophosphamide Or Transplantation) clinical trial demonstrated significant benefits of haematopoietic stem cell transplant (HSCT) versus cyclophosphamide (CTX) in patients with systemic sclerosis. The objective of this study was to test the hypothesis that transplantation stabilises the autoantibody repertoire in patients with favourable clinical outcomes.

METHODS

We used a bead-based array containing 221 protein antigens to profile serum IgG autoantibodies in participants of the SCOT trial.

RESULTS

Comparison of autoantibody profiles at month 26 (n=23 HSCT; n=22 CTX) revealed antibodies against two viral antigens and six self-proteins (SSB/La, CX3CL1, glycyl-tRNA synthetase (EJ), parietal cell antigen, bactericidal permeability-increasing protein and epidermal growth factor receptor (EGFR)) that were significantly different between treatment groups. Linear mixed model analysis identified temporal increases in antibody levels for hepatitis B surface antigen, CCL3 and EGFR in HSCT-treated patients. Eight of 32 HSCT-treated participants and one of 31 CTX-treated participants had temporally varying serum antibody profiles for one or more of 14 antigens. Baseline autoantibody levels against 20 unique antigens, including 9 secreted proteins (interleukins, IL-18, IL-22, IL-23 and IL-27), interferon-α2A, stem cell factor, transforming growth factor-β, macrophage colony-stimulating factor and macrophage migration inhibitory factor were significantly higher in patients who survived event-free to month 54.

CONCLUSIONS

Our results suggest that HSCT favourably alters the autoantibody repertoire, which remains virtually unchanged in CTX-treated patients. Although antibodies recognising secreted proteins are generally thought to be pathogenic, our results suggest a subset could potentially modulate HSCT in scleroderma.

Initiation of an eligibility screening protocol prior to tissue typing of potential stem cell donors resulted in substantial cost savings

e19047

Background: Human Leukocyte Antigen (HLA) typing is a necessary but expensive process to identify suitable donors for allogeneic hematopoietic cell transplantation (HCT) for the treatment of bone marrow disorders and hematologic malignancies. The likelihood of a patient and sibling being fully HLA matched is 25%. An HLA-identical related donor remains the preferred source among HCT recipients due to superior outcomes when compared to unrelated, mismatched, haploidentical, or cord blood. Because of the high probability of finding an HLA matched donor among siblings, and the benefit of quick access to these donors, it had been standard procedure at our institute to test all siblings to identify potential matches. The estimated costs of HLA typing alone is approximately $300-$1000 and is contingent upon the lab utilized and resolution of typing. The costs of HLA typing, additional testing, and screening are significant to patients and health care systems. Methods: Our institution initiated a protocol to assess potential sibling donors prior to HLA typing as per the donor eligibility guidelines of the National Marrow Donor Program (NMDP). From 2018-2020 each sibling was given a questionnaire prior to HLA typing and screened for suitability. If a sibling was determined to be ineligible for donation based on the NMDP guidelines, HLA typing and work up for that sibling was not pursued. Results: Between 2018 and 2020 we identified 789 potential donors for HCT. All potential donors were sent eligibility questionnaires. Based on this screening, 568 potential donors were found to be eligible for donation whereas 221 were ineligible. HLA typing was pursued in all eligible donors. This resulted in and estimated cost savings of $66,000-$221,000 in HLA typing alone. This translated into a substantial health care cost savings for our institution as compared to our prior policy of typing all siblings. Conclusions: Identification and work up for potential HLA matched siblings is critical for identifying optimal donors for HCT. Our previous policy of universal sibling screening was found to be costly due to typing individuals who later were found to be ineligible to donate. We found that the initiation of a simple donor screening protocol that excluded ineligible sibling donors resulted in significant cost savings compared to our prior policy of HLA typing all potential sibling donors. Cost savings are a relevant consideration in all aspects of healthcare and this screening tool could be a practical component of the best practice guidelines for HLA matching and HCT.

Brain volume change after high-dose immunosuppression and autologous hematopoietic cell transplantation for relapsing-remitting multiple sclerosis

BACKGROUND

Brain volume loss (BVL) is commonly observed after high-dose immunosuppression and autologous hematopoietic cell transplantation (HDIT/HCT) for treatment of multiple sclerosis (MS). To better understand the mechanisms of underlying BVL associated with this treatment, we characterized the time courses of whole-brain (WB), grey-matter (GM) and white-matter (WM) volume loss in relapsing-remitting MS (RRMS) patients who received BEAM-based HDIT/HCT.

METHODS

We used Jacobian integration to measure MRI-based WB, GM and WM volume changes up to 5 years after transplant in twenty-four RRMS participants who underwent BEAM-based HDIT/HCT. Using a two-piecewise mixed-effects model, we estimated the short-term (baseline to 1 year) and long-term (beyond 1 year) rates of BVL after HDIT/HCT. We also compared the rates based on the presence of gadolinium-enhancing lesions at baseline, and the maintenance of event-free survival during follow-up.

RESULTS

On average, accelerated short-term BVL of -1.37% (SE: 0.21), -0.86% (SE: 0.28) and -2.18% (SE: 0.26) occurred in WB, GM and WM, respectively. Baseline T1-weighted MRI WM lesion volume was a significant predictor in the WB (short-term) and the WM (short-term and long-term). The average rates of BVL after the initial acceleration were -0.22%/y (SE: 0.10), -0.13%/y (SE: 0.11) and -0.36%/y (SE: 0.11) in the WB, GM and WM, respectively. Participants with gadolinium-enhancing lesions at baseline had significantly higher short-term rates of GM (-1.56% vs. -0.27%, p = 0.01) and WB volume loss (-1.94% vs. -0.81%, p = 0.006) at 1 year follow-up as compared to those without gadolinium-enhancing lesions. WM volume loss was not significantly different (-2.59% vs. -1.66%, p = 0.16). Participants who maintained event-free survival had similar rates of BVL compared to those who did not.

CONCLUSIONS

BVL may accelerate for months after HDIT/HCT. However, over the long-term, adequate HDIT/HCT may reduce BVL rates to those similar to normal aging at the WB level.

Machine learning predicts stem cell transplant response in severe scleroderma

OBJECTIVE

The Scleroderma: Cyclophosphamide or Transplantation (SCOT) trial demonstrated clinical benefit of haematopoietic stem cell transplant (HSCT) compared with cyclophosphamide (CYC). We mapped PBC (peripheral blood cell) samples from the SCOT clinical trial to scleroderma intrinsic subsets and tested the hypothesis that they predict long-term response to HSCT.

METHODS

We analysed gene expression from PBCs of SCOT participants to identify differential treatment response. PBC gene expression data were generated from 63 SCOT participants at baseline and follow-up timepoints. Participants who completed treatment protocol were stratified by intrinsic gene expression subsets at baseline, evaluated for event-free survival (EFS) and analysed for differentially expressed genes (DEGs).

RESULTS

Participants from the fibroproliferative subset on HSCT experienced significant improvement in EFS compared with fibroproliferative participants on CYC (p=0.0091). In contrast, EFS did not significantly differ between CYC and HSCT arms for the participants from the normal-like subset (p=0.77) or the inflammatory subset (p=0.1). At each timepoint, we observed considerably more DEGs in HSCT arm compared with CYC arm with HSCT arm showing significant changes in immune response pathways.

CONCLUSIONS

Participants from the fibroproliferative subset showed the most significant long-term benefit from HSCT compared with CYC. This study suggests that intrinsic subset stratification of patients may be used to identify patients with SSc who receive significant benefit from HSCT.

Extensive intrathecal T cell renewal following hematopoietic transplantation for multiple sclerosis

A recent study of autologous hematopoietic stem cell transplantation (AHSCT) for active relapsing-remitting multiple sclerosis (RRMS) showed efficacy in preventing disease worsening. However, the immunologic basis for efficacy remains poorly defined. Multiple sclerosis pathology is known to be driven by inflammatory T cells that infiltrate the CNS. Therefore, we hypothesized that the preexisting T cell repertoire in the intrathecal compartment of active RRMS participants was ablated and replaced with new clones following AHSCT. T cell repertoires were assessed using high-throughput TCRβ chain sequencing in paired cerebrospinal fluid (CSF) and peripheral blood CD4+ and CD8+ T cells from participants that underwent AHSCT, before and up to 4 years following transplantation. More than 90% of the preexisting CSF repertoire in participants with active RRMS was removed following AHSCT and replaced with clonotypes predominantly generated from engrafted autologous stem cells. Of the preexisting clones in CSF, approximately 60% were also detected in blood before therapy, and concordant treatment effects were observed for clonotypes in both compartments following AHSCT. These results indicate that replacement of the preexisting TCR repertoire in active RRMS is a mechanism for AHSCT efficacy and suggest that peripheral blood could serve as a surrogate for CSF to define mechanisms associated with efficacy in future studies of AHSCT.

Myeloablation followed by autologous stem cell transplantation normalises systemic sclerosis molecular signatures

OBJECTIVE

In the randomised scleroderma: Cyclophosphamide Or Transplantation (SCOT trial) (NCT00114530), myeloablation, followed by haematopoietic stem cell transplantation (HSCT), led to improved clinical outcomes compared with monthly cyclophosphamide (CYC) treatment in systemic sclerosis (SSc). Herein, the study aimed to determine global molecular changes at the whole blood transcript and serum protein levels ensuing from HSCT in comparison to intravenous monthly CYC in 62 participants enrolled in the SCOT study.

METHODS

Global transcript studies were performed at pretreatment baseline, 8 months and 26 months postrandomisation using Illumina HT-12 arrays. Levels of 102 proteins were measured in the concomitantly collected serum samples.

RESULTS

At the baseline visit, interferon (IFN) and neutrophil transcript modules were upregulated and the cytotoxic/NK module was downregulated in SSc compared with unaffected controls. A paired comparison of the 26 months to the baseline samples revealed a significant decrease of the IFN and neutrophil modules and an increase in the cytotoxic/NK module in the HSCT arm while there was no significant change in the CYC control arm. Also, a composite score of correlating serum proteins with IFN and neutrophil transcript modules, as well as a multilevel analysis showed significant changes in SSc molecular signatures after HSCT while similar changes were not observed in the CYC arm. Lastly, a decline in the IFN and neutrophil modules was associated with an improvement in pulmonary forced vital capacity and an increase in the cytotoxic/NK module correlated with improvement in skin score.

CONCLUSION

HSCT contrary to conventional treatment leads to a significant 'correction' in disease-related molecular signatures.

Systemic Sclerosis as an Indication for Autologous Hematopoietic Cell Transplantation: Position Statement from the American Society for Blood and Marrow Transplantation

Systemic sclerosis is a progressive inflammatory disease that is frequently fatal and has limited treatment options. High-dose chemotherapy with autologous hematopoietic cell transplantation (AHCT) has been evaluated as treatment for this disease in observational studies, multicenter randomized controlled clinical trials, and meta-analyses. On behalf of the American Society for Blood and Marrow Transplantation (ASBMT), a panel of experts in transplantation and rheumatology was convened to review available evidence and make a recommendation on AHCT as an indication for systemic sclerosis. Three randomized trials have compared the efficacy of AHCT with cyclophosphamide only, and all demonstrated benefit for the AHCT arm for their primary endpoint (improvement in the American Scleroderma Stem Cell versus Immune Suppression Trial, event-free survival in Autologous Stem Cell Transplantation International Scleroderma trial, and change in global rank composite score in Scleroderma: Cyclophosphamide or Transplantation trial). AHCT recipients also had better overall survival and a lower rate of disease progression. These findings have been confirmed in subsequent meta-analyses. Based on this high-quality evidence, the ASBMT recommends systemic sclerosis should be considered as a "standard of care" indication for AHCT. Close collaboration between rheumatologists and transplant clinicians is critical for optimizing patient selection and patient outcomes. Transplant centers in the United States are strongly encouraged to report patient and outcomes data to the Center for International Blood and Marrow Transplant Research on their patients receiving AHCT for this indication.

Myeloablative Autologous Stem-Cell Transplantation for Severe Scleroderma

BACKGROUND

Despite current therapies, diffuse cutaneous systemic sclerosis (scleroderma) often has a devastating outcome. We compared myeloablative CD34+ selected autologous hematopoietic stem-cell transplantation with immunosuppression by means of 12 monthly infusions of cyclophosphamide in patients with scleroderma.

METHODS

We randomly assigned adults (18 to 69 years of age) with severe scleroderma to undergo myeloablative autologous stem-cell transplantation (36 participants) or to receive cyclophosphamide (39 participants). The primary end point was a global rank composite score comparing participants with each other on the basis of a hierarchy of disease features assessed at 54 months: death, event-free survival (survival without respiratory, renal, or cardiac failure), forced vital capacity, the score on the Disability Index of the Health Assessment Questionnaire, and the modified Rodnan skin score.

RESULTS

In the intention-to-treat population, global rank composite scores at 54 months showed the superiority of transplantation (67% of 1404 pairwise comparisons favored transplantation and 33% favored cyclophosphamide, P=0.01). In the per-protocol population (participants who received a transplant or completed ≥9 doses of cyclophosphamide), the rate of event-free survival at 54 months was 79% in the transplantation group and 50% in the cyclophosphamide group (P=0.02). At 72 months, Kaplan-Meier estimates of event-free survival (74% vs. 47%) and overall survival (86% vs. 51%) also favored transplantation (P=0.03 and 0.02, respectively). A total of 9% of the participants in the transplantation group had initiated disease-modifying antirheumatic drugs (DMARDs) by 54 months, as compared with 44% of those in the cyclophosphamide group (P=0.001). Treatment-related mortality in the transplantation group was 3% at 54 months and 6% at 72 months, as compared with 0% in the cyclophosphamide group.

CONCLUSIONS

Myeloablative autologous hematopoietic stem-cell transplantation achieved long-term benefits in patients with scleroderma, including improved event-free and overall survival, at a cost of increased expected toxicity. Rates of treatment-related death and post-transplantation use of DMARDs were lower than those in previous reports of nonmyeloablative transplantation. (Funded by the National Institute of Allergy and Infectious Diseases and the National Institutes of Health; ClinicalTrials.gov number, NCT00114530 .).

Manufacture of Autologous CD34+ Selected Grafts in the NIAID-Sponsored HALT-MS and SCOT Multicenter Clinical Trials for Autoimmune Diseases

To ensure comparable grafts for autologous hematopoietic cell transplantation (HCT) in the National Institute of Allergy and Infectious Diseases-sponsored Investigational New Drug protocols for multiple sclerosis (HALT-MS) and systemic sclerosis (SCOT), a Drug Master File approach to control manufacture was implemented, including a common Master Production Batch Record and site-specific standard operating procedures with "Critical Elements." We assessed comparability of flow cytometry and controlled rate cryopreservation among sites and stability of cryopreserved grafts using hematopoietic progenitor cells (HPCs) from healthy donors. Hematopoietic Progenitor Cells, Apheresis-CD34+ Enriched, for Autologous Use (Auto-CD34⁺HPC) graft specifications included ≥70% viable CD34⁺ cells before cryopreservation. For the 2 protocols, 110 apheresis collections were performed; 121 lots of Auto-CD34⁺HPC were cryopreserved, and 107 of these (88.4%) met release criteria. Grafts were infused at a median of 25 days (range, 17 to 68) post-apheresis for HALT-MS (n = 24), and 25 days (range, 14 to 78) for SCOT (n = 33). Subjects received precryopreservation doses of a median 5.1 × 10⁶ viable CD34⁺ cells/kg (range, 3.9 to 12.8)  for HALT-MS and 5.6 × 10⁶ viable CD34⁺ cells/kg (range, 2.6 to 10.2) for SCOT. Recovery of granulocytes occurred at a median of 11 days (range, 9 to 15) post-HCT for HALT-MS and 10 days (range, 8 to 12) for SCOT, independent of CD34⁺ cell dose. Subjects received their last platelet transfusion at a median of 9 days (range, 6 to 16) for HALT-MS and 8 days (range, 6 to 23) for SCOT; higher CD34⁺/kg doses were associated with faster platelet recovery. Stability testing of cryopreserved healthy donor CD34⁺ HPCs over 6 months of vapor phase liquid nitrogen storage demonstrated consistent 69% to 73% recovery of viable CD34⁺ cells. Manufacturing of Auto-CD34⁺HPC for the HALT-MS and SCOT protocols was comparable across all sites and supportive for timely recovery of granulocytes and platelets.

Long-term Outcomes After Autologous Hematopoietic Stem Cell Transplantation for Multiple Sclerosis

Importance

Autologous hematopoietic stem cell transplantation (AHSCT) may be effective in aggressive forms of multiple sclerosis (MS) that fail to respond to standard therapies.

Objective

To evaluate the long-term outcomes in patients who underwent AHSCT for the treatment of MS in a large multicenter cohort.

Design, Setting, and Participants

Data were obtained in a multicenter, observational, retrospective cohort study. Eligibility criteria were receipt of AHSCT for the treatment of MS between January 1995 and December 2006 and the availability of a prespecified minimum data set comprising the disease subtype at baseline; the Expanded Disability Status Scale (EDSS) score at baseline; information on the administered conditioning regimen and graft manipulation; and at least 1 follow-up visit or report after transplant. The last patient visit was on July 1, 2012. To avoid bias, all eligible patients were included in the analysis regardless of their duration of follow-up. Data analysis was conducted from September 1, 2014 to April 27, 2015.

Exposures

Demographic, disease-related, and treatment-related exposures were considered variables of interest, including age, disease subtype, baseline EDSS score, number of previous disease-modifying treatments, and intensity of the conditioning regimen.

Main Outcomes and Measures

The primary outcomes were MS progression-free survival and overall survival. The probabilities of progression-free survival and overall survival were calculated using Kaplan-Meier survival curves and multivariable Cox proportional hazards regression analysis models.

Results

Valid data were obtained from 25 centers in 13 countries for 281 evaluable patients, with median follow-up of 6.6 years (range, 0.2-16 years). Seventy-eight percent (218 of 281) of patients had progressive forms of MS. The median EDSS score before mobilization of peripheral blood stem cells was 6.5 (range, 1.5-9). Eight deaths (2.8%; 95% CI, 1.0%-4.9%) were reported within 100 days of transplant and were considered transplant-related mortality. The 5-year probability of progression-free survival as assessed by the EDSS score was 46% (95% CI, 42%-54%), and overall survival was 93% (95% CI, 89%-96%) at 5 years. Factors associated with neurological progression after transplant were older age (hazard ratio [HR], 1.03; 95% CI, 1.00-1.05), progressive vs relapsing form of MS (HR, 2.33; 95% CI, 1.27-4.28), and more than 2 previous disease-modifying therapies (HR, 1.65; 95% CI, 1.10-2.47). Higher baseline EDSS score was associated with worse overall survival (HR, 2.03; 95% CI, 1.40-2.95).

Conclusions and Relevance

In this observational study of patients with MS treated with AHSCT, almost half of them remained free from neurological progression for 5 years after transplant. Younger age, relapsing form of MS, fewer prior immunotherapies, and lower baseline EDSS score were factors associated with better outcomes. The results support the rationale for further randomized clinical trials of AHSCT for the treatment of MS.

High-dose immunosuppressive therapy and autologous HCT for relapsing-remitting MS

OBJECTIVE

To evaluate the safety, efficacy, and durability of multiple sclerosis (MS) disease stabilization after high-dose immunosuppressive therapy (HDIT) and autologous hematopoietic cell transplantation (HCT).

METHODS

High-Dose Immunosuppression and Autologous Transplantation for Multiple Sclerosis (HALT-MS) is a phase II clinical trial of HDIT/HCT for patients with relapsing-remitting (RR) MS who experienced relapses with disability progression (Expanded Disability Status Scale [EDSS] 3.0-5.5) while on MS disease-modifying therapy. The primary endpoint was event-free survival (EFS), defined as survival without death or disease activity from any one of: disability progression, relapse, or new lesions on MRI. Participants were evaluated through 5 years posttransplant. Toxicities were reported using the National Cancer Institute Common Terminology Criteria for Adverse Events (AE).

RESULTS

Twenty-five participants were evaluated for transplant and 24 participants underwent HDIT/HCT. Median follow-up was 62 months (range 12-72). EFS was 69.2% (90% confidence interval [CI] 50.2-82.1). Progression-free survival, clinical relapse-free survival, and MRI activity-free survival were 91.3% (90% CI 74.7%-97.2%), 86.9% (90% CI 69.5%-94.7%), and 86.3% (90% CI 68.1%-94.5%), respectively. AE due to HDIT/HCT were consistent with expected toxicities and there were no significant late neurologic adverse effects noted. Improvements were noted in neurologic disability with a median change in EDSS of -0.5 (interquartile range -1.5 to 0.0; p = 0.001) among participants who survived and completed the study.

CONCLUSION

HDIT/HCT without maintenance therapy was effective for inducing long-term sustained remissions of active RRMS at 5 years.

CLINICALTRIALSGOV IDENTIFIER

NCT00288626.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that participants with RRMS experienced sustained remissions with toxicities as expected from HDIT/HCT.

Survival, and time to an advanced disease state or progression, of untreated patients with moderately severe multiple sclerosis in a multicenter observational database: relevance for design of a clinical trial for high dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation

Despite prolonged survival, patients with multiple sclerosis (MS) experience considerable morbidity, which adversely impacts quality of life. To assess the risk-benefit of a clinical trial of high dose immunosuppressive therapy with autologous hematopoietic stem cell transplantation for MS, we sought to determine the natural history of the disease in a comparison group of untreated patients. We identified 285 individuals with 2132 combined observation years (median: 5.6 years; 5th to 95th percentile: 1-21 years), with Expanded Disability Status Scale (EDSS) scores of 3.0-5.5 at baseline observation. Disease-related mortality was zero at five years, 5.4% at 10 years, and 22% at 15 years (40 patients contributing to the data point; 95% confidence interval: 4-32%). Risk for progression to advanced disability, defined as an EDSS score of 8, was very low for the subgroup with a baseline EDSS score of 3-3.5; however, for those with a baseline EDSS score of 4-5.5, 3% had advanced disability after two years, 5% after three years, 6% after four years, 12% after five years, and 40% after 10 years. The estimated probability of disease progression, defined as an increase in EDSS score by ≥ 1.0 sustained for at least 180 days, was 5% after one year, 14% after two years, 22% after three years, 38% after five years, 57% after 10 years, and-80% after 20 years of observation. The relevance of these features to the design of the clinical trial is discussed.

Discordant functional and inflammatory parameters in multiple sclerosis patients after autologous haematopoietic stem cell transplantation

This article describes outcomes in four patients with advanced multiple sclerosis up to two years after autologous haematopoietic stem cell transplantation using a total-body irradiation-based preparative regimen. MRI and C SF analyses demonstrated clear suppression of the inflammatory processes. The results demonstrate however, a dissociation of inflammation parameters and functional disability findings raising questions about optimal future stem cell transplantatio n strategies for this disease.

High-dose immunosuppressive therapy and autologous hematopoietic cell transplantation for relapsing-remitting multiple sclerosis (HALT-MS): a 3-year interim report

IMPORTANCE

Most patients with relapsing-remitting (RR) multiple sclerosis (MS) who receive approved disease-modifying therapies experience breakthrough disease and accumulate neurologic disability. High-dose immunosuppressive therapy (HDIT) with autologous hematopoietic cell transplant (HCT) may, in contrast, induce sustained remissions in early MS.

OBJECTIVE

To evaluate the safety, efficacy, and durability of MS disease stabilization through 3 years after HDIT/HCT.

DESIGN, SETTING, AND PARTICIPANTS

Hematopoietic Cell Transplantation for Relapsing-Remitting Multiple Sclerosis (HALT-MS) is an ongoing, multicenter, single-arm, phase 2 clinical trial of HDIT/HCT for patients with RRMS who experienced relapses with loss of neurologic function while receiving disease-modifying therapies during the 18 months before enrolling. Participants are evaluated through 5 years after HCT. This report is a prespecified, 3-year interim analysis of the trial. Thirty-six patients with RRMS from referral centers were screened; 25 were enrolled.

INTERVENTIONS

Autologous peripheral blood stem cell grafts were CD34+ selected; the participants then received high-dose treatment with carmustine, etoposide, cytarabine, and melphalan as well as rabbit antithymocyte globulin before autologous HCT.

MAIN OUTCOMES AND MEASURES

The primary end point of HALT-MS is event-free survival defined as survival without death or disease activity from any one of the following outcomes: (1) confirmed loss of neurologic function, (2) clinical relapse, or (3) new lesions observed on magnetic resonance imaging. Toxic effects are reported using National Cancer Institute Common Terminology Criteria for Adverse Events.

RESULTS

Grafts were collected from 25 patients, and 24 of these individuals received HDIT/HCT. The median follow-up period was 186 weeks (interquartile range, 176-250) weeks). Overall event-free survival was 78.4% (90% CI, 60.1%-89.0%) at 3 years. Progression-free survival and clinical relapse-free survival were 90.9% (90% CI, 73.7%-97.1%) and 86.3% (90% CI, 68.1%-94.5%), respectively, at 3 years. Adverse events were consistent with expected toxic effects associated with HDIT/HCT, and no acute treatment-related neurologic adverse events were observed. Improvements were noted in neurologic disability, quality-of-life, and functional scores.

CONCLUSIONS AND RELEVANCE

At 3 years, HDIT/HCT without maintenance therapy was effective for inducing sustained remission of active RRMS and was associated with improvements in neurologic function. Treatment was associated with few serious early complications or unexpected adverse events.

T cell repertoire following autologous stem cell transplantation for multiple sclerosis

Autologous hematopoietic stem cell transplantation (HSCT) is commonly employed for hematologic and non-hematologic malignancies. In clinical trials, HSCT has been evaluated for severe autoimmunity as a method to "reset" the immune system and produce a new, non-autoimmune repertoire. While the feasibility of eliminating the vast majority of mature T cells is well established, accurate and quantitative determination of the relationship of regenerated T cells to the baseline repertoire has been difficult to assess. Here, in a phase II study of HSCT for poor-prognosis multiple sclerosis, we used high-throughput deep TCRβ chain sequencing to assess millions of individual TCRs per patient sample. We found that HSCT has distinctive effects on CD4+ and CD8+ T cell repertoires. In CD4+ T cells, dominant TCR clones present before treatment were undetectable following reconstitution, and patients largely developed a new repertoire. In contrast, dominant CD8+ clones were not effectively removed, and the reconstituted CD8+ T cell repertoire was created by clonal expansion of cells present before treatment. Importantly, patients who failed to respond to treatment had less diversity in their T cell repertoire early during the reconstitution process. These results demonstrate that TCR characterization during immunomodulatory treatment is both feasible and informative, and may enable monitoring of pathogenic or protective T cell clones following HSCT and cellular therapies.

Late infusion of cloned marrow fibroblasts stimulates endogenous recovery from radiation-induced lung injury

In the current study, we used a canine model of radiation-induced lung injury to test the effect of a single i.v. infusion of 10×10⁶/kg of marrow fibroblasts on the progression of damage following 15 Gy exposure to the right lung. The fibroblasts, designated DS1 cells, are a cloned population of immortalized cells isolated from a primary culture of marrow stromal cells. DS1 cells were infused at week 5 post-irradiation when lung damage was evident by imaging with high-resolution computed tomography (CT). At 13 weeks post-irradiation we found that 4 out of 5 dogs receiving DS1 cells had significantly improved pulmonary function compared to 0 out of 5 control dogs (p = 0.047, Fisher’s Exact). Pulmonary function was measured as the single breath diffusion capacity-hematocrit (DLCO-Hct), the total inspiratory capacity (IC), and the total lung capacity (TLC), which differed significantly between control and DS1-treated dogs; p = 0.002, p = 0.005, and p = 0.004, respectively. The DS1-treated dogs also had less pneumonitis detected by CT imaging and an increased number of TTF-1 (thyroid transcription factor 1, NKX2-1) positive cells in the bronchioli and alveoli compared to control dogs. Endothelial-like progenitor cells (ELC) of host origin, detected by colony assays, were found in peripheral blood after DS1 cell infusion. ELC numbers peaked one day after infusion, and were not detectable by 7 days. These data suggest that infusion of marrow fibroblasts stimulates mobilization of ELC, which is associated with a reduction in otherwise progressive radiation-induced lung injury. We hypothesize that these two observations are related, specifically that circulating ELC contribute to increased angiogenesis, which facilitates endogenous lung repair.

Gastric antral vascular ectasia and its clinical correlates in patients with early diffuse systemic sclerosis in the SCOT trial

OBJECTIVE

To describe the prevalence and clinical correlates of endoscopic gastric antral vascular ectasia (GAVE; "watermelon stomach") in early diffuse systemic sclerosis (SSc).

METHODS

Subjects with early, diffuse SSc and evidence of specific internal organ involvement were considered for the Scleroderma: Cyclophosphamide Or Transplant (SCOT) trial. In the screening procedures, all patients underwent upper gastrointestinal endoscopy. Patients were then categorized into those with or without endoscopic evidence of GAVE. Demographic data, clinical disease characteristics, and autoantibody data were compared using Pearson chi-square or Student t tests.

RESULTS

Twenty-three of 103 (22.3%) individuals were found to have GAVE on endoscopy. Although not statistically significant, anti-topoisomerase I (anti-Scl70) was detected less frequently among those with GAVE (18.8% vs 44.7%; p = 0.071). Similarly, anti-RNP antibodies (anti-U1 RNP) showed a trend to a negative association with GAVE (0 vs 18.4%; p = 0.066). There was no association between anti-RNA polymerase III and GAVE. Patients with GAVE had significantly more erythema or vascular ectasias in other parts of the stomach (26.1% vs 5.0%; p = 0.003).

CONCLUSION

Endoscopic GAVE was present on screening in almost one-fourth of these highly selected patients with early and severe diffuse SSc. While anti-Scl70 and anti-U1 RNP trended toward a negative association with GAVE, there was no correlation between anti-RNA Pol III and GAVE. Patients with GAVE had a higher frequency of other gastric vascular ectasias outside the antrum, suggesting that GAVE may represent part of the spectrum of the vasculopathy in SSc.

Transplantation for autoimmune diseases in north and South America: a report of the Center for International Blood and Marrow Transplant Research

Hematopoietic cell transplantation (HCT) is an emerging therapy for patients with severe autoimmune diseases (AID). We report data on 368 patients with AID who underwent HCT in 64 North and South American transplantation centers reported to the Center for International Blood and Marrow Transplant Research between 1996 and 2009. Most of the HCTs involved autologous grafts (n = 339); allogeneic HCT (n = 29) was done mostly in children. The most common indications for HCT were multiple sclerosis, systemic sclerosis, and systemic lupus erythematosus. The median age at transplantation was 38 years for autologous HCT and 25 years for allogeneic HCT. The corresponding times from diagnosis to HCT were 35 months and 24 months. Three-year overall survival after autologous HCT was 86% (95% confidence interval [CI], 81%-91%). Median follow-up of survivors was 31 months (range, 1-144 months). The most common causes of death were AID progression, infections, and organ failure. On multivariate analysis, the risk of death was higher in patients at centers that performed fewer than 5 autologous HCTs (relative risk, 3.5; 95% CI, 1.1-11.1; P = .03) and those that performed 5 to 15 autologous HCTs for AID during the study period (relative risk, 4.2; 95% CI, 1.5-11.7; P = .006) compared with patients at centers that performed more than 15 autologous HCTs for AID during the study period. AID is an emerging indication for HCT in the region. Collaboration of hematologists and other disease specialists with an outcomes database is important to promote optimal patient selection, analysis of the impact of prognostic variables and long-term outcomes, and development of clinical trials.

Autologous hematopoietic cell transplantation following high-dose immunosuppressive therapy for advanced multiple sclerosis: long-term results

The purpose of the study was to determine the long-term safety and effectiveness of high-dose immunosuppressive therapy (HDIT) followed by autologous hematopoietic cell transplantation (AHCT) in advanced multiple sclerosis (MS). Total body irradiation, cyclophosphamide, and antithymocyte globulin were followed by transplantation of autologous, CD34-selected peripheral blood stem cells (PBSC). Neurological examinations, brain MRIs and cerebrospinal fluid (CSF) for oligoclonal bands (OCB) were serially evaluated. Patients (n=26, mean EDSS=7.0, 17 secondary progressive, 8 primary progressive, 1 relapsing/remitting) were followed for a median of 48 months after HDIT followed by AHCT. The 72-month probability of worsening ≥ 1.0 EDSS point was 0.52 (95% CI, 0.30 to 0.75). Five patients had an EDSS at baseline of ≤ 6.0; four of these had not failed treatment at last study visit. OCB in CSF persisted with minor changes in the banding pattern. Four new or enhancing lesions were seen on MRI, all within 13 months of treatment. In this population with high baseline EDSS, a significant proportion of patients with advanced MS remained stable as long as 7 years after transplant. Non-inflammatory events may have contributed to neurological worsening after treatment. HDIT/AHCT may be more effective in patients with less advanced relapsing/remitting MS.

A retrospective comparison of tacrolimus versus cyclosporine with methotrexate for immunosuppression after allogeneic hematopoietic cell transplantation with mobilized blood cells

This retrospective study was performed to compare results with tacrolimus versus cyclosporine in combination with methotrexate for immunosuppression after allogeneic hematopoietic cell transplantation (HCT) with granulocyte colony-stimulating factor-mobilized blood cells. The cohort included 456 consecutive patients who received first allogeneic T cell-replete HCT with mobilized blood cells from related or unrelated donors after high-intensity conditioning for treatment of hematologic malignancies. Study endpoints included grades II-IV acute graft-versus-host disease (aGVHD), grades III-IV aGVHD, chronic GVHD (cGVHD), end of treatment for cGVHD, overall mortality, disease-free survival (DFS), recurrent malignancy, and nonrelapse mortality (NRM). Adjusted multivariate Cox regression analysis showed no statistically significant differences between tacrolimus and cyclosporine for any of the endpoints tested. Although the size of the cohort is not sufficient to exclude clinically meaningful differences in outcomes, these results support the continued use of cyclosporine at centers that have not adopted tacrolimus as the standard of care after HCT with mobilized blood cells after high-intensity conditioning regimens. A larger registry study should be performed to provide more definitive information comparing outcomes with the 2 calcineurin inhibitors.

Autologous hematopoietic cell transplantation for multiple sclerosis: a systematic review

BACKGROUND AND OBJECTIVES

The purpose of this systematic review was to evaluate the safety and efficacy of autologous hematopoietic cell transplantation in patients with progressive multiple sclerosis (MS) refractory to conventional medical treatment.

METHODS

Eight case series met our a priori inclusion criteria for the primary outcome of progression-free survival. Individual study quality was rated using an 11-item scale for case series. The strength of the overall body of evidence for each outcome was rated using a system developed by the ECRI Institute. Data from different studies were statistically combined using meta-analysis. An additional six studies were included for a summary of mortality and morbidity.

RESULTS

For secondary progressive MS, immunoablative therapy with autologous bone marrow/peripheral blood stem cell transplantation was associated with higher progression-free survival (up to 3 years following treatment) when using intermediate-intensity conditioning regimens compared with high-intensity conditioning regimens. The evidence was insufficient to determine whether the treatment was effective in patients with other types of MS. Treatment-related mortality was about 2.7%.

CONCLUSIONS

Patients with secondary progressive MS refractory to conventional medical treatment have longer progression-free survival following autologous stem cell transplantation with intermediate-intensity conditioning regimens than with high-intensity conditioning regimens.

A preclinical model of double- versus single-unit unrelated cord blood transplantation

Cord blood transplantation (CBT) with units containing total nucleated cell (TNC) dose >2.5 x 10(7)/kg is associated with improved engraftment and decreased transplant-related mortality. For many adults no single cord blood units are available that meet the cell dose requirements. We developed a dog model of CBT to evaluate approaches to overcome the problem of low cell dose cord blood units. This study primarily compared double- versus single-unit CBT. Unrelated dogs were bred and cord blood units were harvested. We identified unrelated recipients that were dog leukocyte antigen (DLA)-88 (class I) and DLA-DRB1 (class II) allele-matched with cryopreserved units. Each unit contained Collapse

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MESH Headings

• Animals
• Cord Blood Stem Cell Transplantation/adverse effects
• Cord Blood Stem Cell Transplantation/methods
• Disease Models, Animal
• Dogs
• Female
• Graft Rejection/immunology
• Male
• Survival Rate

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Grants

• U19 AI067770-02 NIAID NIH HHS
• U19 AI067770-030005 NIAID NIH HHS
• U19 AI067770-05 NIAID NIH HHS
• U19 AI 067770 NIAID NIH HHS
• U19 AI067770-01 NIAID NIH HHS
• R01 DK042716 NIDDK NIH HHS
• DK42716 NIDDK NIH HHS
• R01 DK042716-15 NIDDK NIH HHS
• P30 CA015704 NCI NIH HHS
• CA78902 NCI NIH HHS
• U19 AI067770 NIAID NIH HHS
• U19 AI067770-050005 NIAID NIH HHS
• P30 CA015704-35 NCI NIH HHS
• CA15704 NCI NIH HHS
• U19 AI067770-010005 NIAID NIH HHS
• R01 DK042716-16 NIDDK NIH HHS
• P30 CA015704-34 NCI NIH HHS
• U19 AI067770-04 NIAID NIH HHS
• P01 CA078902 NCI NIH HHS
• P01 CA078902-11 NCI NIH HHS
• P01 CA078902-10 NCI NIH HHS
• U19 AI067770-040005 NIAID NIH HHS
• U19 AI067770-020005 NIAID NIH HHS

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Outcome of allogeneic hematopoietic cell transplantation from HLA-identical siblings for severe aplastic anemia in patients over 40 years of age

Patients with severe aplastic anemia (SAA) over 40 years of age are often not offered treatment with hematopoietic cell transplantation (HCT) because of concerns about treatment-related morbidity or mortality. To evaluate this risk, we analyzed outcomes after allogeneic HCT from HLA-identical sibling donors for all older patients with SAA at our center since 1988. The 23 consecutive patients ranged in age from 40 to 68 years. The conditioning regimen was cyclophosphamide (200 mg/kg) and horse antithymocyte globulin. Methotrexate and cyclosporine were given for postgrafting immunosuppression. The cumulative incidences of grades II, III, and IV acute graft-versus-host-disease were 30%, 4%, and 0%, respectively; that for chronic GVHD was 26%. With a median follow-up of 9.1 years, overall survival was 65%. Documented infections within 1 month before HCT were significantly associated with risk of early treatment-related mortality (P < .001). The median time to discontinuation of posttransplant immunosuppression was 6.2 (range: 5.9-92.0) months. Three patients developed superficial basal cell carcinoma between 5.5 and 15 years after HCT. Our data favor a practice of extending HLA-identical sibling HCT for treatment of SAA in patients older than 40 years of age who are without significant medical comorbidities.

Hematopoietic stem cell transplantation for multiple sclerosis: collaboration of the CIBMTR and EBMT to facilitate international clinical studies

Clinical investigation of autologous hematopoietic stem cell transplantation (HSCT) as therapy for multiple sclerosis (MS) has been ongoing for over a decade. While several phase II studies have been finalized or are in progress, no definitive prospective randomized studies comparing HSCT versus alternative therapies for MS have been completed. In this conference report of North American and European experts who are involved in the care of MS patients, including neurologists and HSCT physicians, and representatives of the Center for International Blood and Marrow Transplant Research (CIBMTR) and European Group for Blood and Marrow Transplantation (EBMT), we (1) critically review progress to date in HSCT for MS; (2) describe current registry based projects including long-term follow-up studies in HSCT for MS and harmonization of the MS disease-specific research forms that will be used in future by both databases; (3) discuss challenges in study design for a prospective randomized clinical trial of HSCT versus alternative therapy for MS such as feasibility, and the importance of multidisciplinary clinical teams, need for a large sample size and duration of observation required for outcomes assessment; and (4) address future directions in HSCT therapy for MS. To undertake a definitive multicenter clinical trial in autologous HSCT for MS, it will be important to begin well in advance to assemble the team, evaluate proposals for study design, and consider options for the infrastructure and logistical support that will be needed. International collaboration, including partnership with the CIBMTR and EBMT, may be desirable and may in fact be critical for successful completion of a definitive comparative study.

Longitudinal assessment of morbidity and acute graft-versus-host disease after allogeneic hematopoietic cell transplantation: retrospective analysis of a multicenter phase III study

Because morbidity early after hematopoietic cell transplantation (HCT) results in large part from the development of acute graft-versus-host disease (GVHD), we previously proposed that a longitudinal assessment of morbidity involving the skin, liver, and gastrointestinal (GI) tract might provide a more complete, objective approach for comparing 2 arms of open-label randomized clinical trials for acute GVHD prevention. In this study, we determined both morbidity across time and GVHD across time in a retrospective analysis of a database from an open-label randomized clinical trial comparing tacrolimus/methotrexate and cyclosporine/methotrexate after myeloablative conditioning and marrow transplantation from HLA-matched unrelated donors. The results confirm differences in overall morbidity across time in patients with peak grade II-IV GVHD compared with those with grade 0-I GVHD, but no significant differences in morbidity associated with grade II GVHD compared with grade 0-I GVHD. We observed less skin morbidity and a trend toward less liver morbidity across time in the tacrolimus group (P = .04 and .09, respectively), but not for GI morbidity or overall morbidity, despite significantly decreased skin and liver stages and overall grades of GVHD across time in this group. Thus, our objective assessment of differences in morbidity (regardless of cause) as a measure of acute GVHD in a randomized clinical trial of acute GVHD prevention has only limited utility. The difficulty of demonstrating clinical benefits from objective parameters, such as survival and morbidity, and the subjectivity of grading acute GVHD emphasize the need for blinded assessments in clinical trials of GVHD prevention.

Cutaneous chronic graft-versus-host disease does not have the abnormal endothelial phenotype or vascular rarefaction characteristic of systemic sclerosis

BACKGROUND

The clinical and histologic appearance of fibrosis in cutaneous lesions in chronic graft-versus -host disease (c-GVHD) resembles the appearance of fibrosis in scleroderma (SSc). Recent studies identified distinctive structural changes in the superficial dermal microvasculature and matrix of SSc skin. We compared the dermal microvasculature in human c-GVHD to SSc to determine if c-GVHD is a suitable model for SSc.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed skin biopsies of normal controls (n = 24), patients with SSc (n = 30) and c-GVHD with dermal fibrosis (n = 133)). Immunostaining was employed to identify vessels, vascular smooth muscle, dermal matrix, and cell proliferation. C-GVHD and SSc had similar dermal matrix composition and vascular smooth muscle pathology, including intimal hyperplasia. SSc, however, differed significantly from c-GVHD in three ways. First, there were significantly fewer (p = 0.00001) average vessels in SSc biopsies (9.8) when compared with c-GVHD (16.5). Second, in SSc, endothelial markers were decreased significantly (19/19 and 12/14 for VE cadherin and vWF (p = <0.0001 and <0.05), respectively). In contrast, 0/13 c-GVHD biopsies showed loss of staining with canonical endothelial markers. Third, c-GVHD contained areas of microvascular endothelial proliferation not present in the SSc biopsies.

CONCLUSIONS/SIGNIFICANCE

The sclerosis associated with c-GVHD appears to resemble wound healing. Focal capillary proliferation occurs in early c-GVHD. In contrast, loss of canonical endothelial markers and dermal capillaries is seen in SSc, but not in c-GVHD. The loss of VE cadherin in SSc, in particular, may be related to microvascular rarefaction because VE cadherin is necessary for angiogenesis. C-GVHD is a suitable model for studying dermal fibrosis but may not be applicable for studying the microvascular alterations characteristic of SSc.

Sirolimus in combination with cyclosporine or tacrolimus plus methotrexate for prevention of graft-versus-host disease following hematopoietic cell transplantation from unrelated donors

In 2 consecutive prospective clinical trials, we evaluated the efficacy of sirolimus together with a calcineurin inhibitor (cyclosporine or tacrolimus) and low-dose methotrexate for prevention of graft-versus-host disease (GVHD) after unrelated hematopoietic cell transplantation (HCT). Nine patients received sirolimus with cyclosporine, and 17 received sirolimus with tacrolimus. The incidence of grade II-IV GVHD was 77%, with the median onset at day 7 after HCT. Because of toxicity, administration of sirolimus was discontinued earlier than planned in 11 patients, but after the onset of GVHD. Three patients developed renal failure requiring hemodialysis. Accrual in both studies was terminated because of lack of efficacy. In these studies, the addition of sirolimus to regimens containing a calcineurin inhibitor and methotrexate appeared to cause toxicity and provided no detectable improvement in preventing GVHD.

Micro magnetic resonance angiography of the finger in systemic sclerosis

OBJECTIVE

To characterize vascular lesions in SSc disease with high-resolution magnetic resonance angiography (Micro-MRA) of the finger.

METHODS

Eight SSc subjects and eight age- and sex-matched healthy controls were recruited for this study. Among the SSc subjects, the mean +/- s.d. age was 54.5 +/- 4.9 yrs, and the mean +/- s.d. duration of disease was 8.3 +/- 8.4 yrs. The numbers of SSc subjects that had telangiectasia, calcinosis and impaired finger flexion were 3, 2 and 3, respectively. The 2D time-of-flight micro-MRA was performed on a 3T clinical MRI scanner using a custom-designed finger coil with an in-plane resolution of 0.16 x 0.21 mm(2) and slice thickness of 1.2 mm. The data for the proper palmar digital artery lumen area, the number of visible dorsal digital veins and a semi-quantitative vascular score, which evaluates the overall integrity of digital vessels, were independently evaluated by two experienced reviewers who were blinded to the status of the subject.

RESULTS

Micro-MRA detected significant differences in the digital vasculature between SSc subjects and healthy volunteers. The SSc subjects had a significantly decreased digital artery lumen area (0.13 +/- 0.06 vs 0.53 +/- 0.26 mm(2), P < 0.001), a reduced number of digital veins (0.63 +/- 1.06 vs 3.13 +/- 0.99, P = 0.001) and a lowered overall vascular score (1.75 +/- 1.04 vs 3.5 +/- 0.53, P = 0.001). The study also found that both the digital artery lumen area (Pearson's; r = -0.72, P = 0.044) and vascular scores (Spearman's; rho = -0.75, P = 0.047) of the SSc subjects were inversely correlated with the duration of the disease.

CONCLUSIONS

Micro-MRA can be used to identify and quantitatively characterize the vascular disease in SSc fingers. The parameters derived from micro-MRA could potentially be used as prospective biomarkers for clinical evaluation.

Alloreactivity and anti-tumor activity segregate within two distinct subsets of cytokine-induced killer (CIK) cells: implications for their infusion across major HLA barriers

Donor-derived cytokine-induced killer (CIK) can be infused as adoptive immunotherapy after hematopoietic cell transplant (HCT). Promising results were recently reported in HLA-identical HCT, where mild grafts versus host (GVH) events were observed. To extend this strategy across major HLA barriers (e.g. HLA-haploidentical HCT), further studies on CIK cells' alloreactivity are needed. We hypothesized that alloreactivity and anti-tumor activity of CIK cells segregate within two different cell subsets and could consequently be separated according to CD56 and CD3 expression. We tested CIK cells expanded from seven patients who underwent HCT as treatment of metastatic colorectal cancer. We found that CIK cells maintained their alloreactivity across major HLA barriers when tested as bulk population; after CD56-positive selection, anti-tumor activity was restricted to the CD3+/CD56+ cell fraction and alloreactivity versus HLA-mismatched PBMC was restricted to the CD3+/CD56- cell fraction. Bulk CIK cells from engrafted patients did not exhibit alloreactivity in response to host- or donor-derived PBMC, confirming their low potential for GVH across minor HLA barriers. Moreover, we tested if CIK cells expanded from engrafted patients after HCT were as effective as donor-derived ones and could be considered as an alternative option. The expansion rate and tumor cell killing was comparable to that observed in sibling donors. In conclusion, depletion of CD3+/CD56- cells might reduce the risk of GVH without affecting the tumor-killing capacity and could help extending CIK infusions across major HLA barriers. Engrafted patients after HCT could also be considered as an effective alternative option to donor-derived CIK cells.

Lentiviral vector conferring resistance to mycophenolate mofetil and sensitivity to ganciclovir for in vivo T-cell selection

Several clinical studies of gene-modified T cells have shown limited in vivo function of the cells, immunogenicity of the transgene, and lack of a selective advantage for gene-modified T cells. To address these problems, we developed a lentiviral vector (LV) that provides a selectable, proliferative advantage and potentially decreases immunogenicity for transduced T cells. The bicistronic vector expressed two genes linked with an internal ribosomal entry site. One gene is a variant of the inosine monophosphate dehydrogenase 2, inosine monophosphate dehydrogenase (IMPDH(IY)), conferring resistance to the immunosuppressive drug mycophenolate mofetil (MMF). The other is a suicide gene, herpes simplex virus thymidine kinase (HSV-TK), rendering proliferating cells sensitive to ablation with ganciclovir, fused to the selectable transmembrane marker DeltaCD34 (DeltaCD34/TK). Cells transduced with LV-DeltaCD34/TK.IMPDH(IY) were efficiently enriched by immunomagnetic selection for CD34, proliferated in 0.5-5 microM MMF, and were killed by 0.5-25 microg ml(-1) ganciclovir. We demonstrate efficient selection and killing of gene-modified cells and suggest LV-DeltaCD34/TK.IMPDH(IY)-transduced T cells could be used to facilitate allogeneic hematopoietic cell engraftment. The expression of IMPDH(IY) would allow in vivo selection with MMF, and DeltaCD34/TK expression would allow rapid and safe elimination of transduced T cells if graft-versus-host disease developed.

Intussusception in canine recipients of hematopoietic cell grafts and surgical correction

Intussusception is a common complication after canine hematopoietic cell transplantation (HCT). The present study was undertaken to evaluate predisposing factors of intussusception and to test whether intussusception can be managed surgically during the period immediately after HCT. We determined the incidence of intussusception after HCT was performed in 325 canine recipients (autologous, n = 43; allogeneic, n = 282) during the interval from January 2002 to May 2005. Intussusception was diagnosed in 16 of 325 dogs (4.9%). Intussusception was not significantly associated with the dose of irradiation, source of hematopoietic graft, use of immunosuppressive agents, gender, or age at transplant. A group of 9 of the affected dogs underwent small-bowel resection after diagnosis, and 7 were managed without surgical intervention. Despite complicating factors such as gastrointestinal toxicity and low neutrophil and platelet counts induced by the marrow conditioning regimen and the use of immunosuppressive agents, successful surgical management of intussusception was achieved in 6 of 9 dogs, as compared with successful management of 0 of 7 without surgery. Intussusception did not recur after surgical intervention in any dog. Recent HCT and post-transplant immunosuppressive therapy are not absolute contraindications to surgical intervention for intussusception in canine recipients of HCT.

Hematopoietic cell transplantation in patients with myelodysplastic syndrome or acute myeloid leukemia arising from myelodysplastic syndrome: similar outcomes in patients with de novo disease and disease following prior therapy or antecedent hematologic disorders

We analyzed outcomes after hematopoietic cell transplantation (HCT) in 257 patients, 3 to 72.7 years old (median, 43 y), with secondary myelodysplastic syndrome (MDS) including those with transformation to acute myeloid leukemia (tAML). Conditioning regimens included high-dose total-body irradiation (TBI)/chemotherapy (n = 83); busulfan (BU)/cyclophosphamide (CY) (BUCY, n = 122; with BU targeting [tBUCY], n = 93); fludarabine (Flu) with tBU (FLUtBU; n = 12); Flu plus 200 cGy TBI (n = 26); and miscellaneous regimens (n = 14). Donors were HLA-identical or partially mismatched family members in 135 and unrelated individuals in 122 patients. Five-year relapse-free survival was highest (43%) and nonrelapse mortality lowest (28%) among tBUCY-conditioned patients. Outcomes were compared with results in 339 patients who received transplants for de novo MDS/tAML, and a multivariate analysis failed to show significant differences in outcome between the 2 cohorts. Relapse probability and relapse-free survival correlated significantly with disease stage (P < .001) and karyotype (P < .001). Relapse incidence was lower (P = .003) and relapse-free survival superior (P = .02) with unrelated donor transplants. The data suggest that overall inferior outcome in patients with secondary MDS/tAML was related to the frequency of high-risk cytogenetics. For both cohorts, transplantation outcomes improved over the time interval studied.

High-dose immunosuppressive therapy and autologous hematopoietic cell transplantation for severe systemic sclerosis: long-term follow-up of the US multicenter pilot study

More effective therapeutic strategies are required for patients with poor-prognosis systemic sclerosis (SSc). A phase 2 single-arm study of high-dose immunosuppressive therapy (HDIT) and autologous CD34-selected hematopoietic cell transplantation (HCT) was conducted in 34 patients with diffuse cutaneous SSc. HDIT included total body irradiation (800 cGy) with lung shielding, cyclophosphamide (120 mg/kg), and equine antithymocyte globulin (90 mg/kg). Neutrophil and platelet counts were recovered by 9 (range, 7 to 13) and 11 (range, 7 to 25) days after HCT, respectively. Seventeen of 27 (63%) evaluable patients who survived at least 1 year after HDIT had sustained responses at a median follow-up of 4 (range, 1 to 8) years. There was a major improvement in skin (modified Rodnan skin score, -22.08; P < .001) and overall function (modified Health Assessment Questionnaire Disability Index, -1.03; P < .001) at final evaluation. Importantly, for the first time, biopsies confirmed a statistically significant decrease of dermal fibrosis compared with baseline (P < .001). Lung, heart, and kidney function, in general, remained clinically stable. There were 12 deaths during the study (transplantation-related, 8; SSc-related, 4). The estimated progression-free survival was 64% at 5 years. Sustained responses including a decrease in dermal fibrosis were observed exceeding those previously reported with other therapies. HDIT and autologous HCT for SSc should be evaluated in a randomized clinical trial.

Multiple sclerosis conference synopsis and discussion: cellular therapy for treatment of autoimmune diseases (October 2005)

At a conference held in October 2005, participants presented studies on high dose immunosuppression with hematopoietic cell transplant (HCT) for multiple sclerosis (MS), including neuroimmunological and magnetic resonance imaging (MRI) mechanistic approaches, clinical registry reports, and ongoing or newly-designed protocols. A discussion panel considered questions on how to define success, timing of controlled clinical trials, difficulty in patient recruitment, and future direction of high dose therapy.

Potential Risk of Progressive Multifocal Leukoencephalopathy With Natalizumab Therapy

Natalizumab (Tysabri) is an effective therapy for multiple sclerosis. Recently, 3 patients who were treated with natalizumab developed progressive multifocal leukoencephalopathy (PML), an opportunistic infection of the brain with the polyomavirus JC. The pathogenesis of natalizumab-associated PML may be different from that of PML not associated with the drug. We reviewed biologically feasible interventions for patients diagnosed as having PML or other infections while receiving natalizumab therapy. Existing interventions include antiviral treatment, immunomodulatory therapies, hematopoietic growth factors, plasma exchange, intravenous immunoglobulins, and leukapheresis and autotransfusion of leukocytes. In addition, we examined the feasibility of experimental therapies, including small interfering RNA, the in vivo use of antiserum, and recombinant natalizumab-blocking molecules. There is only circumstantial evidence that any of the proposed treatments will benefit patients with multiple sclerosis treated with natalizumab who may develop PML. In addition, the expected incidence of PML in this patient population will likely be too low to test any of the proposed interventions in a controlled manner. Because it is currently impossible to identify patients at risk, and thus to prevent PML as a consequence of natalizumab therapy, it is important that neurologists be aware of possible therapeutic interventions.

Optimized Transduction of Canine Paediatric CD34+ Cells Using an MSCV-based Bicistronic Vector

We have used a murine MSCV-based bicistronic retroviral vector, containing the common gamma chain (gammac) and enhanced green fluorescent protein (EGFP) cDNAs, to optimize retroviral transduction of canine cells, including an adherent canine thymus fibroblast cell line, Cf2Th, as well as normal canine CD34(+) bone marrow (BM) cells. Both canine cell types were shown to express Ram-1 (the amphotropic retroviral receptor) mRNA. Supernatants containing infectious viruses were produced using both stable (PA317) and transient (Phoenix cells) amphotropic virus producer cell lines. Centrifugation (spinfection) combined with the addition of polybrene produced the highest transduction efficiencies, infecting approximately 75% of Cf2Th cells. An average of 11% of highly enriched canine CD34(+) cells could be transduced in a protocol that utilized spinfection and plates coated with the fibronectin fragment CH-296 (Retronectin). Indirect assays showed the vector-encoded canine gammac cDNA produced a gammac protein that was expressed on the cell surface of transduced cells. This strategy may result in the transduction of sufficient numbers of CD34(+) BM cells to make the treatment of canine X-linked severe combined immunodeficiency and other canine genetic diseases feasible.

Partial donor-specific tolerance to delayed skin grafts after rejection of hematopoietic cell graft

BACKGROUND

Donor-specific tolerance (DST) is induced after allogeneic hematopoietic cell transplantation (HCT) and is a potential strategy for prolonging survival of solid organ grafts. DST may persist in recipients with transient mixed hematopoietic chimerism (MC) when solid organ transplantation and HCT are done concomitantly.

METHODS

In a canine model of allogeneic HCT after nonmyeloablative conditioning, DST to skin grafts was evaluated in dog leukocyte antigen (DLA)-identical recipients with stable MC (n=11), or after rejection of the hematopoietic cell (HC) graft (n=19).

RESULTS

There was significant improvement in the survival of DLA-identical HC donor-derived skin grafts in recipients with MC compared to normal recipients (n=7; P<0.0001). However, HC donor-derived skin grafts in four recipients with MC developed an inflammatory reaction without skin graft loss. This may represent partial DST. Survival of DLA-identical HC donor-derived skin grafts was also significantly prolonged compared to normal recipients even when skin grafting was delayed until after rejection of the HC graft (P=0.002). An inflammatory reaction developed in all nine of the surviving HC donor-derived skin grafts in this group, but there was no graft loss at last follow-up (median, 30 [range, 9-84] weeks). An increased time to rejection of the hematopoietic graft was associated with prolonged survival of the subsequent skin graft (P=0.02).

CONCLUSION

In a model of stable MC, DST to skin grafts may be complete or partial. Partial DST can persist after HC graft rejection even if solid organ transplantation is delayed. Further investigations are required to understand the mechanisms responsible for DST after allogeneic HCT.

Optimizing a canine survival model of orthotopic lung transplantation

INTRODUCTION

While acute models of orthotopic lung transplantation have been described in dogs, the technical considerations of developing a survival model in this species have not been elaborated. Herein, we describe optimization of a canine survival model of orthotopic lung transplantation.

METHODS

Protocols of orthotopic left lung transplantation and single lung ventilation were established in acute experiments (n=9). Four dogs, serving as controls, received autologous, orthotopic lung transplants. Allogeneic transplants were performed in 16 DLA-identical and 16 DLA-mismatched unrelated recipient dogs. Selective right lung ventilation was utilized in all animals. A Malecot tube was left in the pleural space connected to a Heimlich valve for up to 24 hours. To date, animals have been followed up to 24 months by chest radiography, pulmonary function tests, bronchoscopy with lavage, and open biopsies.

RESULTS

Long-term survival was achieved in 34/36 animals. Two recipients died intraoperatively secondary to cardiac arrest. All animals were extubated on the operating table, and in all cases the chest tube was removed within 24 hours. Major complications included thrombosis of the pulmonary artery and subcritical stenosis of bronchial anastamosis. One recipient underwent successful treatment of a small bowel intussusception.

CONCLUSIONS

We report our experience in developing a survival canine model of orthotopic single lung transplantation. While short-term survival following canine lung transplantation is achievable, we report particular considerations that facilitate animal comfort, early extubation, and lung reexpansion in the immediate postoperative period, further optimizing use of this species for experimental modeling of long-term complications after lung transplantation.