High-dose Cytotoxic Therapy Research Articles

Bone remodeling in survivors of pediatric hematopoietic stem cell transplantation: Impact of heavy resistance training.

Early-onset osteoporosis is a frequent late effect after pediatric hematopoietic stem cell transplantation (HSCT). It remains unknown if physical training can improve bone formation in these patients, as the transplantation procedure may cause sustained dysregulation of the bone-forming osteoblast progenitor cells. We aimed to explore the effect of resistance training on bone remodeling in long-term survivors of pediatric HSCT. In this prospective, controlled intervention study, we included seven HSCT survivors and 15 age- and sex-matched healthy controls. The participants completed a 12-week heavy load, lower extremity resistance training intervention with three weekly sessions. We measured fasting serum levels of the bone formation marker "N-terminal propeptide of type I procollagen" (P1NP), and the bone resorption marker "C-terminal telopeptide of type I collagen" (CTX). The hypothesis was planned before data collection began. The trial was registered at Clinicaltrials.gov before including the first participant, with trial registration no. NCT04922970. Resistance training led to significantly increased levels of fasting P1NP in both patients (from 57.62 to 114.99ng/mL, p=.03) and controls (from 66.02 to 104.62ng/mL, p<.001). No significant changes in fasting CTX levels were observed. Despite previous high-dose cytotoxic therapy, long-term survivors of pediatric HSCT respond to resistance training with improvement of bone formation, comparable to that of healthy controls. This suggests that resistance training might be a promising non-pharmacological approach to prevent the early decline in bone mass, and should be considered as part of a follow-up program to counteract long-term sequela after pediatric HSCT.

Therapy-Related Myeloid Neoplasm Has a Distinct Pro-Inflammatory Bone Marrow Microenvironment and Delayed DNA Damage Repair

Introduction: Therapy-related myeloid neoplasms (t-MN) are associated with extremely poor clinical outcomes in otherwise long-term cancer survivors. t-MN accounts for ~20% of cases of myeloid neoplasms and is expected to rise due to the increased use of chemotherapy/radiotherapy (CT/RT) and improved cancer survivorship. Historically, t-MN was considered a direct consequence of DNA damage induced in normal hematopoietic stem cells (HSC) by DNA damaging cytotoxics. However, these studies have largely ignored the bone marrow (BM) microenvironment and the effects of age and concurrent/previous cancers. Aim: We performed an exhaustive functional study of mesenchymal stromal cells (MSC) obtained from a comparatively large cohort of t-MN patients and carefully selected control populations to evaluate the long-term damage induced by cytotoxic therapy to BM microenvironment and its impact on malignant and normal haematopoiesis. Methods: Four different cohorts were used: (1) t-MN, in which myeloid malignancy occurred after CT/RT for a previous cancer (n=18); (2) patients with multiple cancer and in which a myeloid neoplasm developed following an independent cancer which was not treated with CT/RT (MC-MN; n=10); (3) primary MN (p-MN; n=7) untreated and without any prior cancer or CT/RT; (4) age-matched controls (HC; n=17). Morphology, proliferation, cellular senescence, differentiation potential and γH2AX DNA damage response was performed. Stem/progenitor supportive capacity was assessed by co-culturing haematopoietic stem cells on MSC feeder-layer in long-term culture initiating assay (LTC-IC). Cytokine measurements were performed using 38-plex magnetic bead panel (Millipore) and RNA sequencing libraries were prepared with Illumina TruSeq Total RNA protocol for 150bp paired-end sequencing on a NextSeq500 instrument. Functional enrichment analysis was performed using EnrichR software. Results: MSC cultured from t-MN patients were significantly different from HC, p-MN and MC-MN MSC according to multiple parameters. They exhibited aberrant morphology consisting of large, rounded and less adhesive cells compared to typical spindle-shaped morphology observed with controls. MSC from myeloid neoplasm also showed impaired proliferation, senescence, osteo- and adipogenic differentiation with t-MN MSC showing the greatest differences. DNA repair was dramatically impaired compared to p-MN and HC (Fig.1A). Importantly, these aberrant t-MN MSC were not able to support normal or autologous in vitro long-term haematopoiesis (Fig.1B). The biological characteristic and poor haematopoietic supportive capacity of MSC could be "cell-intrinsic" or driven by an altered paracrine inflammatory microenvironment. Interestingly, several inflammatory cytokines were higher in t-MN compared with marrow interstitial fluid obtained from p-MN patients (Fig.1Ci) and many of these including Fractalkine, IFNα2, IL-7 and G-CSF were also significantly higher in t-MN MSC conditional media (Fig.1Cii). Together, this data suggest that t-MN microenvironment is distinct from p-MN with paracrine production of pro-inflammatory milieu that may contribute to poor HSC supportive capacity. Preliminary whole transcriptome analysis revealed differential gene expression between t-MN and HC (Fig.1Di) and p-MN MSC. Importantly, the deregulated genes play critical role in cell cycle, DNA damage repair, and cellular senescence pathways explaining phenotypical characteristic of t-MN MSC (Fig.1Dii). Moreover CXCL12 expression, a key regulator of haematopoiesis, was significantly lower in t-MN compared to HC (p=0.002) and p-MN MSC (p=0.009), thus explaining poor HSC supportive capacity. The key difference between the p-MN, MC-MN and t-MN is prior exposure to CT/RT. To study this we obtained MSC from two t-MN patients for whom we had samples at the time of their primary cancer, post high-dose chemotherapy and at the time of t-MN. MSC displayed aberrant proliferation and differentiation capacity after high-dose cytotoxic therapy (2 to 4 years prior to developing t-MN) and remained aberrant at t-MN diagnosis (Fig.1E). Conclusions: BM-MSC from t-MN patients are significantly abnormal compared with age-matched controls and typical myeloid neoplasm. Importantly, prior CT/RT leads to long-term irreversible damage to the BM microenvironment which potentially contributes to t-MN pathogenesis. Disclosures Hughes: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hiwase:Novartis Australia: Research Funding.

Therapy-Related Myeloid Neoplasms Following Autologous Stem Cell Transplantation: The Prevalence of Chip Mutations at Time of Transplantation — a Single Center Experience

Introduction: Therapy-related myeloid neoplasms (tMN) are high-risk conditions evolved after exposure to a number of agents, including cytotoxic therapy, and include myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and myeloproliferative neoplasms (MPN). As such cytoreduction as part of autologous stem cell transplantation (ASCT) increases the risk of developing tMN. Importantly, both the use of ASCT and the incidence of tMN are rising. The recent characterization of clonal hematopoiesis of indeterminate potential (CHIP) has, in preliminary reports, been shown to increase the risk of developing de novo hematological disease as well as tMN. We hypothesized that patients with non-myeloid primary disease who develop tMN after ASCT, had detectable myeloid mutations at time of transplantation, and that these may represent a risk factor in the development of tMN. This study characterizes tMN patients previously subjected to ASCT and investigates whether CHIP mutations are present in hematopoietic stem cells at time of ASCT.Methods: The cohort of this observational study consists of patients treated with ASCT at the Department of Hematology, Aarhus University Hospital (Denmark) from 1989 to 2016. Cases were identified via the Danish Pathology Registry and all tMN diagnoses were verified by the same experienced hemopathologist (GBK). Only cases from patients with non-myeloid primary disease, who were diagnosed with tMN after being treated with ASCT (minimum latency being 90 days) were included. 36 cases with available leukapheresis products were identified out of a cohort of 1130 patients.Samples collected from leukapheresis prior to ASCT were subjected to targeted next-generation sequencing (NGS), using the commercially available panel “Myeloid Solution” (Sophia Genetics, Saint Sulpice, Switzerland), covering 30 genes relevant for myeloid neoplasms, joined with a bioinformatics pipeline from Sophia Genetics. Samples from 31 patients have been subjected to NGS. Variants residing in or within ± 25 nucleotides of coding exons and with coverage >5000 at the variant site were reported. Indels present in polynucleotide stretches were excluded.Data for continuous variables age, latency to tMN and survival were analyzed as one sample from a normal distribution based on the Students t-test. Normality was assessed via Q-Q plot. Estimates are reported with a 95% confidence intervals (Stata, version 15.1, StataCorp LLC, TX, USA).Results: The cohort consisted of 25 males (80.7%) and 6 females (19.3%), with an estimated median age at ASCT of 58 years (CI 95% 54;63). Estimated median time to tMN was 3.7 years (CI 95% 2.5;5.4) and estimated median survival after tMN diagnosis was 132 days (CI 95% 71;246). At time of tMN diagnosis, 14 patients had a poor risk karyotype and 9 patients had intermediate risk karyotype (hereof 4 normal karyotype). Karyotype was not evaluated in 8 patients.CHIP mutations were detected in stem cell enriched leukapheresis products from 21 patients (67.7%). Of these, we found multiple mutations in 14 patients (66%) and in one patient as many as 6 CHIP mutations. Point mutations were frequently found in the DNMT3A gene and was present in 16 out of 21 patients (76%). Six patients had more than one DNMT3A mutation, one of which had 5 separate DNMT3A mutations. Other mutations detected were TP53 (6/21), TET2 (5/21), ASXL1 (4/21), EZH2 (1/21), WT1 (1/21), JAK2 (1/21), NRAS (1/21), HRAS (1/21), BRAF (1/21), CSF3R (1/21), SF3B1 (1/21), ZRSR2 (1/21), CALR (1/21), SRSF2 (1/21).Conclusion: We found that CHIP mutations can be detected at time of ASCT in patients being treated for non-myeloid diseases. We hypothesize that presence of CHIP mutations at ASCT may predict the development of tMN and as such serve as a biomarker in this setting. We speculate that high-dose cytotoxic therapy may provide an evolutionary advantage for hematopoietic clones containing CHIP mutations. On the other hand, we cannot rule out that the cytoreduction administered prior at ASCT may be a main contributor to the tMN development. To address this as well as the development of tMN in the post-ASCT phase, a nested case-control study will be necessary. DisclosuresNo relevant conflicts of interest to declare.

A Risk Stratification Model Using Quantification of Circulating Plasma Cells in Multiple Myeloma Prior to Autologous Stem Cell Transplantation in the Era of Novel Agents

Background: The presence of circulating plasma cells (CPCs) is associated with an adverse prognosis in multiple myeloma along the entire spectrum of disease. However, the impact of CPCs prior to autologous stem cell transplantation (ASCT) has not been defined in the era of novel agents. The objective of this study is to assess the impact of the presence and number of CPCs before transplant using 6-color multiparameter flow cytometry (MFC). We also explored the additional prognostic implications of CPCs over the current paradigm for risk stratification at transplant, including high-risk (HR) cytogenetics and disease status at transplant by the IMWG criteria. Methods: A total of 1113 consecutive patients transplanted between 2007 and 2015 in Mayo Clinic were included in the study. Flow-cytometry of peripheral blood to identify clonal CPCs is routinely performed in all patients before ASCT in Mayo Clinic, Rochester. The mononuclear cells from peripheral blood samples are isolated by Ficoll gradient and subsequently stained with antibodies to CD19, CD38, CD45, CD138 and cytoplasmic kappa (κ) and lambda (λ) immunoglobulin light chains. Clonality is assessed by light chain restriction (κ:λ expression ratio of 4:1 [κ restricted] or 150,000 cellular events. For samples where less than 150,000 clonal events are examined, the number of final clonal events is adjusted to 150,000 events. HR cytogenetics by fluorescence in situ hybridization (FISH) on bone marrow (BM) plasma cells was defined by one of the following abnormalities: t(4;14), del(17p), t(14;16), t(14;20) or +1q, detected at any time point from diagnosis to transplant. Patients who had insufficient plasma cells for FISH analysis in BM specimens were not included in the denominator to calculate the percentage of patients with HR cytogenetics. The primary end-points of this study were post-transplant response, PFS and OS. Result: CPCs were detected in 238 out of 1113 (21.4%) patients, with the median number of CPCs being 82 (range, 1-102381) per 150,000 events. The median age of patients at transplant was 62 years. A total of 1097 (99%) patients had received novel agent based induction therapy with PIs and IMiDs, including 458 (41%) patients who had received both PIs and IMiDs. 401 (36%) patients had received post-transplant maintenance or consolidation therapy. The frequency of t(4;14) in BMPCs was significantly higher in patients with CPCs compared to those without [15.2 vs 7.0% for t(4;14); P P 400 (n=51; 4.6%). The number of patients achieving stringent complete response post-transplant in groups with no CPCs, 0 400 was 310 (36%), 31 (16%) and 3 (6%) respectively ( P P P 400 had an increased risk of death, independent of the presence of HR cytogenetics and disease status at transplant. Conclusion: Our study shows the strong negative prognostic impact of CPCs prior to transplant on post-transplant response and survival in MM in the era of novel agents. The proposed risk stratification model can be easily employed with simple equipment and should be routinely incorporated in the pre-transplant workup. Detailed epigenomic, genomic and transcriptomic analysis of CPCs is urgently needed to uncover the biological basis of resistance to both high-dose cytotoxic therapy and novel agents and identify potential avenues of targeted therapy against CPCs. Disclosures Kumar: Onyx: Consultancy, Research Funding; Kesios: Consultancy; Celgene: Consultancy, Research Funding; Glycomimetics: Consultancy; AbbVie: Research Funding; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity9s Board of Directors or advisory committees; Millennium: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding. Dispenzieri: Takeda: Membership on an entity9s Board of Directors or advisory committees, Research Funding; Alnylam: Research Funding; GSK: Membership on an entity9s Board of Directors or advisory committees; pfizer: Research Funding; Prothena: Membership on an entity9s Board of Directors or advisory committees; Celgene: Research Funding; Jannsen: Research Funding. Kapoor: Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Gertz: Sandoz Inc: Honoraria; NCI Frederick: Honoraria; Celgene: Honoraria; Alnylam Pharmaceuticals: Research Funding; GSK: Honoraria; Novartis: Research Funding; Research to Practice: Honoraria, Speakers Bureau; Med Learning Group: Honoraria, Speakers Bureau; Ionis: Research Funding; Prothena Therapeutics: Research Funding; Annexon Biosciences: Research Funding.

Commentary on Thomas and Epstein: "Bone Marrow Transplantation in Acute Leukemia".

See related article by Thomas and Epstein, [Cancer Res 1965;25:1521–4][1] . Visit the Cancer Research 75th Anniversary [timeline][2]. Fifty years ago, Dr. E.D. Thomas and Dr. R.B. Epstein published the intellectual and scientific basis for the use of high-dose cytotoxic therapy, specifically

Isolated Clonal Cytogenetic Abnormalities after High-Dose Therapy

Therapy-related myeloid neoplasms (t-MN) are well-recognized complications of high-dose cytotoxic therapy (HDT), such as autologous stem cell transplantation (ASCT). Clonal marrow cytogenetic abnormalities (CMCA) in the setting of normal bone marrow pathology have also been reported after HDT, but their significance remains unclear. We retrospectively evaluated occurrences of CMCA and t-MN in 785 patients treated with HDT at Johns Hopkins University between 1997 and 2007. Most patients received ASCT, but 106 patients who received high-dose cyclophosphamide without ASCT were also included in this study, as this is our institutional standard for malignant and nonmalignant lymphoproliferative disorders in need of HDT. Twenty-two patients developed t-MN, with an estimated cumulative incidence of 3.5% at 4 years. Eleven patients developed isolated CMCA, either transient or persistent without pathologic evidence of t-MN. Altogether, only 20 of the patients with reported CMCA subsequently developed t-MN during the follow-up period. Therefore, in the absence of pathologic evidence of t-MN, CMCA should not be considered diagnostic of t-MN.

Outcome Of Pregnancy After Autologous Hematopoietic Stem Cell Transplantation (AHSCT) For Autoimmune Diseases (AD): A Retrospective Study Of The EBMT Autoimmune Diseases Working Party (ADWP)

Introduction AHSCT is increasing used to control severe and refractory autoimmune diseases (AD). Many patients (pts) are women of reproductive age with a potential desire for pregnancy, especially with control of AD. However, high dose cytotoxic therapy is associated with an age dependent risk of temporary or permanent ovarian and/or endometrial damage. Although childbirth has been sporadically reported after AHSCT for AD, the incidence, complications and outcomes of pregnancy in this group have never been characterised. We present the first multicenter retrospective analysis of pregnancy in patients who underwent AHSCT for AD. Patients and Methods The study was designed as a multicenter retrospective study of data registered in the EBMT database with supplementary information requested with a specific questionnaire sent to each centre. Inclusion criteria were: female pts aged &gt;18 and 50 years receiving AHSCT for AD between 1994-2011. Over this time period 588 adult female patients fulfilling inclusion criteria were identified in the EBMT database and collaborating centres. Results Twenty-two pregnancies were reported in 15 pts between 1997-2010 2013, with 4 pts having 2 pregnancies, and one pt having 4 pregnancies, amounting to approximately 2% of total eligible registrations. Indications for AHSCT included multiple sclerosis (7 pts), systemic sclerosis (5 pts), rheumatoid Arthritis (1 pt), juvenile idiopathic arthritis (1 pt) and Takayasu disease (1 pt). All pts had received standard immunosuppressive +/- cytotoxic treatment for AD prior to mobilisation and AHSCT. The most common mobilization regimen was cyclophosphamide (2-4g/m2) and G-CSF. Conditioning for AHSCT was high dose cyclophosphamide (200mg/kg) in 7 pts, BEAM in 7 pts and one pt received BCNU (300mg/m2) with cyclophosphamide (150g/kg). Serotherapy was used in 10 patients (ATG in 9, ALG in 1). None received TBI. Of the 22 reported pregnancies, 20 were due to natural conception and 2 required assisted conception (two with in vitro fertilization). Fifteen pregnancies (68%) were successful, while seven (38%) were unsuccessful due to ectopic pregnancy (n=1), spontaneous abortion (n=4), and spontaneous fetal death (n=1). and induced abortion (n=1). Other serious adverse events included gestational diabetes mellitus (n=1), congestive heart failure and atrial fibrillation (n=1) and pre-term labor (n=1). Five serious adverse events occurred during first pregnancies, and 2 during second pregnancies. Exacerbations of AD occurred in 2 pts during second pregnancies. In all other patients the AD remained stable throughout pregnancy and post-partum. No maternal mortality was associated with pregnancy or post-partum. The status of the AD at most recent follow up was reported as remission (5 pts), improvement (4 pts), stabilization (3 pts), progression (2 pts) and 1 death due to AD progression. There were no reports of congenital, developmental or any other disease in the children of these pregnancies. Discussion This retrospective analysis confirms that pregnancy is feasible in some pts following AHSCT for severe AD. The outcome of pregnancy is generally good and most lead to the birth of healthy children. It is unclear whether the reported rates of adverse obstetric events exceed that of the general population, but exacerbation of underlying autoimmune disorder is possible. In pts who have undergone AHSCT for AD who wish to plan a pregnancy, we recommend close interdisciplinary collaboration involving obstetricians and relevant AD specialists. However, the reported frequency of pregnancy was relatively rare, and we continue to recommend consideration of embryo or ovum cryopreservation prior to AHSCT as per current ADWP guidelines (Snowden et al BMT 2012;47:770-90) Disclosures: No relevant conflicts of interest to declare.

Low-Dose Total Body Irradiation and Fludarabine Conditioning for HLA Class I-Mismatched Donor Stem Cell Transplantation and Immunologic Recovery in Patients with Hematologic Malignancies: A Multicenter Trial

HLA-mismatched grafts are a viable alternative source for patients without HLA-matched donors receiving ablative hematopoietic cell transplantation (HCT), although their use in reduced intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning HCT has been not well established. Here, we extended HCT to recipients of HLA class I-mismatched grafts to investigate whether NMA conditioning can establish stable donor engraftment. Fifty-nine patients were conditioned with fludarabine (Flu) 90 mg/m(2) and 2 Gy total body irradiation (TBI), followed by immunosuppression with cyclosporine (CsA) 5.0 mg/kg twice a day and mycophenolate mofetil (MMF) 15 mg/kg 3 times a day for transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSCs) from related (n = 5) or unrelated donors (n = 54) with 1 antigen +/- 1 allele HLA class I mismatch or 2 HLA class I allele mismatches. Sustained donor engraftment was observed in 95% of the evaluable patients. The incidence of grade II-IV acute and extensive chronic graft-versus-host disease (aGVHD, cGVHD) was 69% and 41%, respectively. The cumulative probability of nonrelapse mortality (NRM) was 47% at 2 years. Two-year overall and progression-free survival (OS, PFS) was 29% and 28%, respectively. NMA conditioning with Flu and low-dose TBI, followed by HCT using HLA class I-mismatched donors leads to successful engraftment and long-term survival; however, the high incidence of aGVHD and NRM needs to be addressed by alternate GVHD prophylaxis regimens.

Reduced-intensity conditioning transplantation in myeloid malignancies

The development of non-myeloablative and reduced-intensity conditioning regimens has enabled older or medically infirm patients with myeloid malignancies to be treated with allogeneic hematopoietic cell transplantation (HCT). The regimens are sufficiently immunosuppressive to allow engraftment of allogeneic cells and they rely largely on graft-versus-leukemia effects rather than high-dose cytotoxic therapy to eliminate malignant cells. Overall 2-5-year survivals after allogeneic HCT in older patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) have ranged from 25% to 64%. Outcomes were comparable for human leukocyte antigen-matched related and unrelated grafts. The best results were seen in patients transplanted in the first or second remission. Relapse and progressive disease continue to be problems, particularly in patients with large tumor burdens at the time of HCT. Reduction of the tumor burden before HCT with targeted therapy such as radiolabelled anti-CD45 antibody may improve the outcome. Despite still existing problems, early results in elderly patients with AML/MDS have been encouraging.

Treatment of intractable pulmonary hemorrhage in two patients with childhood systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown etiology with multisystem involvement. A number of pulmonary complications including pleuritis, pneumonitis, infectious pneumonia, and pulmonary hemorrhage, have been reported in patients with SLE. Pulmonary hemorrhage is a major life-threatening manifestation in children and adolescents with SLE. Mycophenolate mofetil is an immunosuppressive agent used in solid organ transplantation, and it may play an increasing role in autoimmune disease. In this report, we present two cases of childhood SLE with recurrent pulmonary hemorrhage, which were unresponsive to treatment with high-dose corticosteroids, cytotoxic therapy, IVIG, plasmaphoresis, and supportive therapy, but responded to IV mycophenolate mofetil. A multimodal therapy including mycophenolate mofetil was effective in treatment of these two children.

Comparison of Outcomes of HLA-Matched Related, Unrelated, or HLA-Haploidentical Related Hematopoietic Cell Transplantation following Nonmyeloablative Conditioning for Relapsed or Refractory Hodgkin Lymphoma

We compared the outcome of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) for patients with relapsed or refractory Hodgkin lymphoma (HL) based on donor cell source. Ninety patients with HL were treated with nonmyeloablative conditioning followed by HCT from HLA-matched related, n=38, unrelated, n=24, or HLA-haploidentical related, n=28 donors. Patients were heavily pretreated with a median of 5 regimens and most patients had failed autologous HCT (92%) and local radiation therapy (83%). With a median follow-up of 25 months, 2-year overall survivals, progression-free survivals (OS)/(PFS), and incidences of relapsed/progressive disease were 53%, 23%, and 56% (HLA-matched related), 58%, 29%, and 63% (unrelated), and 58%, 51%, and 40% (HLA-haploidentical related), respectively. Nonrelapse mortality (NRM) was significantly lower for HLA-haploidentical related (P=.02) recipients compared to HLA-matched related recipients. There were also significantly decreased risks of relapse for HLA-haploidentical related recipients compared to HLA-matched related (P=.01) and unrelated (P=.03) recipients. The incidences of acute grades III-IV and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were 16%/50% (HLA-matched related), 8%/63% (unrelated), and 11%/35% (HLA-haploidentical related). These data suggested that salvage allogeneic HCT using nonmyeloablative conditioning provided antitumor activity in patients with advanced HL; however, disease relapse/progression continued to be major problems. Importantly, alternative donor stem cell sources are a viable option.

Predictive factors for outcomes after reduced intensity conditioning hematopoietic stem cell transplantation for hematological malignancies: a 10-year retrospective analysis from the Société Française de Greffe de Moelle et de Thérapie Cellulaire

This retrospective study analyzed the impact of demographic and transplantation variables on outcomes of 1108 patients who have undergone allogeneic hematopoietic stem cell transplantation after reduced intensity conditioning (RIC HSCT) for hematological malignancies and were reported to the Société Française de Greffe de Moelle et de Thérapie Cellulaire registry between November 1994 and December 2004. Only 442 patients (40%) were in complete remission (CR) at time of transplantation. Peripheral blood stem cells were used in the majority of patients (n = 878; 79%), 255 patients received fludarabine and low-dose total body irradiation, while 465 patients (42%) fludarabine and busulfan with rabbit anti-thymocyte globulins (ATG). The impact of demographic and transplant variables was studied on overall (OS) and event-free survival (EFS) in univariate and multivariate analysis. With a median follow-up of 21 months, 3-year probability of OS and EFS was 42% and 30%, respectively, and treatment-related mortality was 15% at 2 years. The multivariate analysis showed a significant negative impact on OS and EFS of the absence of CR status before transplantation; conditioning regimen, including >10 mg/kg ATG; and minor ABO incompatibility. In conclusion, this study highlights the major impact on RIC HSCT outcome of disease status before transplantation, ATG dose and ABO incompatibility.

Stem cell transplantation in rheumatoid arthritis

The therapeutic potential of high dose cytotoxic therapy and stem cell transplantation (SCT) in severe rheumatoid arthritis (RA) was originally supported by animal studies and serendipitous clinical cases where allogeneic and autologous procedures were shown to ameliorate and potentially cure the disease. Phase I and Phase II clinical studies established the feasibility, safety and efficacy of autologous stem cell mobilisation and transplantation. Although it was clear that the effects of high dose chemotherapy and autologous SCT could safely achieve profound responses, sustained control of disease usually required the reintroduction of disease modifying agents. Responses were improved with dose escalation of the conditioning regimen, and also with post-SCT therapy, such as rituximab, but were not observed with graft manipulation. Phase III studies were attempted, but recruitment was compromised by the increasingly widespread use of biological anti-rheumatic agents. Autologous SCT is now only reasonably considered in relatively rare patients whose disease has resisted conventional and biological treatments, and small numbers of cases continue to be registered with the EBMT. Occasional patients treated with allogeneic and syngeneic SCT continue to stimulate academic interest, particularly as some appear to be cured, but significant logistical and toxicity issues mean that routine and widespread application is unrealistic. In summary, SCT continues to have a limited therapeutic potential in rare patients with RA refractory to modern therapy and sufficient fitness for the procedure. From a scientific perspective, ablation of the dysfunctional rheumatoid immune system and its reconstruction with SCT has provided useful insights into the pathophysiology of RA.

Drug Metabolism Gene Polymorphisms and the Risk of Hepatic Sinusoidal Obstruction Syndrome in Children with Inherited Diseases Receiving Haematopoietic Stem Cell Transplantation.

Hepatic Sinusoidal Obstruction Syndrome (SOS) following high dose cytotoxic therapy remains a serious complication after heamatopoietic stem cell transplantation (HSCT). Genetic polymorphisms that interfere with metabolism of drugs used in conditioning regimens have been associated with SOS after HSCT. In order to study this association in children given a HSCT for inherited diseases of the heamatopoietic system we have analyzed candidate genes in 99 children: 35 who developed SOS and in 64 children who did not develop SOS; both groups were transplanted in the same center and matched for year of transplant (from 1998 to 2004). Four families of candidate genes were analyzed: P450 cytochrome [CYP2B6*2(C64T), *3(C777A), *4(A785G), *5(C1459T), *6(G516T)], Glutathione-S-Transferases [GSTM1 (null), GSTT1 (null), GSTP1 (A313G)], Methylenetetrahydrofolate reductase [MTHFR (C677T)] and Vitamin D receptor [VDR (ApaI, TaqI and BsmI)]. The most frequent diagnosis was severe combined immunodeficiency. The two groups had no statistical differences for gender, diagnosis, type of transplant and source of stem cells. Conditioning regimen consisted in busulfan and cyclophosphamide in 91% of SOS patients and 87% of non-SOS patients (p=ns). There was no statistical difference on the frequency of all gene polymorphisms studied in both groups of patients, except for the gene CYP2B6*2 (C64T). In fact, the mutant allele T (genotypes CT or TT) was present in 31% of SOS patients and 9% of remainders (p=0.01). CYP2B6 is known to play an important role in the metabolism of chemotherapeutic agents such as cyclophosphamide (CY). In conclusion, we found that the polymorphism in CYP2B6*2 allele of the P450 cytochrome family is more frequent in children with inherited diseases who have developed SOS after HSCT than in those who did not develop SOS. This finding may define better surveillance and prophylaxis of SOS for children with the mutant allele of CYP2B6*2 given a HSCT.

Overcoming T cell–mediated rejection of bone marrow allografts by T-regulatory cells: Synergism with veto cells and rapamycin

Recently, we have shown that anti-third-party cytotoxic T lymphocytes (CTLs) depleted of alloreactivity against the host are endowed with marked veto activity and can facilitate bone marrow (BM) allografting without graft-versus-host disease. We also demonstrated synergism between rapamycin (RAPA) and the veto cells. CD4(+)CD25(+) T-regulatory (Treg) cells are suppressor cells that can enhance alloengraftment. We investigated whether donor Tregs would be synergistic with veto CTLs and RAPA in augmenting alloengraftment or, conversely, would suppress veto CTL effects. Lethally irradiated C3H mice were transplanted at day 2 after irradiation with Balb-nude BM. Graft rejection was induced by purified host-type T cells infused 1 day prior to BMT. The addition of Tregs led to moderate enhancement of engraftment. RAPA at different doses was synergistic with Tregs. The addition of veto CTLs to Tregs enabled reducing the effective RAPA dose fourfold. Combining all three agents was necessary to overcome rejection at low-dose RAPA. Chimerism analysis at 5 to 9 months revealed a significant presence of host-type cells coexisting with the predominant donor T cells, suggesting that tolerance had been attained. The synergistic effects between Tregs, veto CTLs, and RAPA offer an attractive approach for facilitating alloengraftment.

Autologous stem cell transplantation in the treatment of adults with acute myeloid leukaemia

Most adult patients under 60 years with acute myeloid leukaemia (AML) who achieve a complete remission after induction chemotherapy will relapse if they do not receive further therapy. Consolidation treatment with autologous stem cell transplantation (SCT) is one option that has been studied extensively. High-dose cytotoxic therapy followed by autologous SCT or intensive cycles of chemotherapy furnish overall approximately similar probabilities of survival when applied in first remission. Here, we present a concise update regarding the place of autologous SCT in the treatment of AML. Particular issues discussed are the value of autologous SCT in different prognostic subsets of AML and the value of autologous mobilised peripheral blood stem cell transplants, which offer a much faster haematopoietic recovery.

Mesenchymal Stem Cells in Autoimmune Disease

Autoimmune diseases afflict more than 3% of the U.S. population. Current therapy for mild to moderate cases is symptomatic, however advanced cases suffer high morbidity and mortality. Advanced patients have benefited from stem cell therapy in the form of bone marrow transplantation in conjunction with high-dose cytotoxic therapy. Broader application of stem cell therapy requires better understanding of how adult stem cells affect development and foster treatment of autoimmune pathologies, and of better ways to manipulate the host immune responses. While extensive research documents the role of hematopoietic stem cells (HSCs) in autoimmune disease, few studies have addressed if and how mesenchymal stem cells (MSCs) contribute to their etiopathology. Recent characterization of MSCs and their role in hematopoiesis and immune modulation suggest that their potential for cell therapy extends beyond their traditional accessory function in HSC engraftment. MSCs contribute significantly to tissue restructuring and immune functioning, in addition to facilitating durable, long-lasting stem cell engraftment. MSCs are relatively easy to obtain and expand in in vitro cultures, rendering them a prime candidate for genetic manipulations for stem cell therapy. They have the potential to differentiate into multiple lineages such as osteoblasts, adipose tissue, cartilage, tendon, and stromal cells. The role of MSCs for autoimmune disease therapy could thus be based both on immune function modulation and contribution to hematopoiesis. In this review, we examine the biology of MSCs, and their potential for cell therapy of autoimmune disease.

Mesenchymal Stem Cells in Autoimmune Disease

Autoimmune diseases afflict more than 3% of the U.S. population. Current therapy for mild to moderate cases is symptomatic, however advanced cases suffer high morbidity and mortality. Advanced patients have benefited from stem cell therapy in the form of bone marrow transplantation in conjunction with high-dose cytotoxic therapy. Broader application of stem cell therapy requires better understanding of how adult stem cells affect development and foster treatment of autoimmune pathologies, and of better ways to manipulate the host immune responses. While extensive research documents the role of hematopoietic stem cells (HSCs) in autoimmune disease, few studies have addressed if and how mesenchymal stem cells (MSCs) contribute to their etiopathology. Recent characterization of MSCs and their role in hematopoiesis and immune modulation suggest that their potential for cell therapy extends beyond their traditional accessory function in HSC engraftment. MSCs contribute significantly to tissue restructuring and immune functioning, in addition to facilitating durable, long-lasting stem cell engraftment. MSCs are relatively easy to obtain and expand in in vitro cultures, rendering them a prime candidate for genetic manipulations for stem cell therapy. They have the potential to differentiate into multiple lineages such as osteoblasts, adipose tissue, cartilage, tendon, and stromal cells. The role of MSCs for autoimmune disease therapy could thus be based both on immune function modulation and contribution to hematopoiesis. In this review, we examine the biology of MSCs, and their potential for cell therapy of autoimmune disease.

Multiple sclerosis

Autologous transplants for severe and refractory multiple sclerosis (MS) were proposed in 1997 and have been performed on about 200 selected patients worldwide. Phase I/II clinical studies have shown that high-dose immunosuppressive therapy suppresses inflammation in the CNS and may delay the progression of clinical disease. The procedure is associated with toxicity from the high-dose cytotoxic therapy and a risk of serious infections. There is a transplant-related mortality risk of 1–5%, requiring careful patient selection before transplantation. Treatment should be reserved for patients who have a significant chance of response, i.e. young patients with low disability scores but rapidly progressing disease who have inflammatory rather than neurodegenerative changes in the CNS. The long term effect of high-dose immunosuppression after transplantation on the frequency of relapse or progression of MS is unclear, but the initial concept of immune ablation by high-dose therapy and the reconstitution of normal immunity and tolerance from transplant-derived lymphocyte progenitors has given way to the concept of ‘resetting’ the immune system. The clinical effect of transplantation remains to be demonstrated in comparative studies.

Reovirus oncolysis as a novel purging strategy for autologous stem cell transplantation

AbstractHematologic stem cell rescue after high-dose cytotoxic therapy is extensively used for the treatment of many hematopoietic and solid cancers. Gene marking studies suggest that occult tumor cells within the autograft may contribute to clinical relapse. To date purging of autografts contaminated with cancer cells has been unsuccessful. The selective oncolytic property of reovirus against myriad malignant histologies in in vitro, in vivo, and ex vivo systems has been previously demonstrated. In the present study we have shown that reovirus can successfully purge cancer cells within autografts. Human monocytic and myeloma cell lines as well as enriched ex vivo lymphoma, myeloma, and Waldenström macroglobulinemia patient tumor specimens were used in an experimental purging model. Viability of the cell lines or purified ex vivo tumor cells of diffuse large B-cell lymphoma, chronic lymphocytic leukemia, Waldenström macroglobulinemia, and small lymphocytic lymphoma was significantly reduced after reovirus treatment. Further, [35S]-methionine labeling and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of cellular proteins demonstrated reovirus protein synthesis and disruption of host cell protein synthesis as early as 24 hours. Admixtures of apheresis product with the abovementioned tumor cells and cell lines treated with reovirus showed complete purging of disease. In contrast, reovirus purging of enriched ex vivo multiple myeloma, Burkitt lymphoma, and follicular lymphoma was incomplete. The oncolytic action of reovirus did not affect CD34+ stem cells or their long-term colony-forming assays even after granulocyte colony-stimulating factor (G-CSF) stimulation. Our results indicate the ex vivo use of an unattenuated oncolytic virus as an attractive purging strategy for autologous stem cell transplantations. (Blood. 2003;102:377-387)