High-dose immunoablation with autologous haematopoietic stem cell transplantation in aggressive multiple sclerosis: a single centre 10-year experience.

There are multiple sclerosis patients who suffer from an aggressive course of the disease with severe relapses and rapid accumulation of disability despite adequate treatment. In such cases high-dose immunoablation with autologous haematopoietic stem cell transplantation (ASCT) may be considered. Our objective was to report our experience with 26 multiple sclerosis patients treated with ASCT within the years 1998-2008. Twenty-six patients (Expanded Disability Status Scale 2.5-7.5 (median 6.0), multiple sclerosis duration 2-19 years (median 7)) with aggressive multiple sclerosis underwent autologous haematopoietic stem cell transplantation. Stem cells were mobilized by high-dose cyclophosphamide and granulocyte colony-stimulating factor, BEAM (carmustine, etoposide, cytarabine, melphalan) was used for immunoablation. Patients were evaluated at baseline and every six months post ASCT for adverse events and clinical outcome. Follow-up period was 11-132 months (median 66). Progression-free survival was calculated using the Kaplan- Meier method. At 3 and 6 years of follow-up 70.8% and 29.2% of patients respectively were free of progression. Patients with relapsing multiple sclerosis course, disease duration <5 years and age <35 years had a more favourable outcome. There was no death within 100 days after ASCT. We conclude that ASCT represents a viable and effective treatment option for aggressive multiple sclerosis.

Nature of frequent deletions in CEBPA.

C/EBPalpha (CCAAT/enhancer binding protein alpha) belongs to the family of leucine zipper transcription factors and is necessary for transcriptional control of granulocyte, adipocyte and hepatocyte differentiation, glucose metabolism and lung development. C/EBPalpha is encoded by an intronless gene. CEBPA mutations cause a myeloid differentiation block and were detected in acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), multiple myeloma and non-Hodgkin's lymphoma (NHL) patients. In this study we identified in 41 individuals from 824 screened individuals (290 AML patients, 382 MDS patients, 56 NHL patients and 96 healthy individuals) a single class of 23 deletions in CEBPA gene which involved a direct repeat of at least 2 bp. These mutations are characterised by the loss of one of two same repeats at the ends of deleted sequence. Three most frequent repeats included in these deletions in CEBPA gene are CGCGAG (493-498_865-870), GCCAAGCAGC (508-517_907-916) and GG (486-487_885-886), all according to GenBank accession no. NM_004364.2. A mechanism for deletion formation between two repetitive sequences can be recombination events in the repair process. Double-stranded cut in DNA can initiate these recombination events of adjacent DNA sequences.

CEBPA polymorphisms and mutations in patients with acute myeloid leukemia, myelodysplastic syndrome, multiple myeloma and non-Hodgkin's lymphoma.

The transcription factor CCAAT/enhancer binding protein (C/EBP)alpha is a myeloid-specific transcription factor which is required for normal myeloid differentiation. C/EBPalpha is encoded by an intronless gene that is 2783 bp long and maps to human chromosome 19q13.1. C/EBPalpha is a member of the basic region leucine zipper (bZIP) class of DNA-binding proteins. The loss of function of C/EBPalpha has leukemogenic potential. Four types of polymorphisms and 25 mutations (3 already known mutations and 22 novel mutations) were detected in CEBPA (gene for the transcription factor CCAAT/enhancer binding protein (C/EBP) alpha) in analysed samples from 390 patients with myelodysplastic syndrome (MDS) and hematologic malignancies. CEBPA mutations were found in 14/152 (9.2%) of acute myeloid leukemia (AML) patients' samples, 6/143 (4.2%) of MDS patients' samples, 2/56 (3.6%) of non-Hodgkin's lymphoma (NHL) patients' samples and 2/39 (5.1%) of multiple myeloma (MM) patients' samples. No C/EBPalpha mutations were detected in healthy donors (41 individuals). We discuss how these mutations can affect the cellular function of C/EBPalpha and block the myeloid differentiation.

Autologous bone marrow transplantation in patients with subacute and chronic spinal cord injury.

Stem cell transplants into spinal cord lesions may help to improve regeneration and spinal cord function. Clinical studies are necessary for transferring preclinical findings from animal experiments to humans. We investigated the transplantation of unmanipulated autologous bone marrow in patients with transversal spinal cord injury (SCI) with respect to safety, therapeutic time window, implantation strategy, method of administration, and functional improvement. We report data from 20 patients with complete SCI who received transplants 10 to 467 days postinjury. The follow-up examinations were done at 3, 6, and 12 months after implantation by two independent neurologists using standard neurological classification of SCI, including the ASIA protocol, the Frankel score, the recording of motor and somatosensory evoked potentials, and MRI evaluation of lesion size. We compared intra-arterial (via catheterization of a. vertebralis) versus intravenous administration of all mononuclear cells in groups of acute (10-30 days post-SCI, n=7) and chronic patients (2-17 months postinjury, n=13). Improvement in motor and/or sensory functions was observed within 3 months in 5 of 6 patients with intra-arterial application, in 5 of 7 acute, and in 1 of 13 chronic patients. Our case study shows that the implantation of autologous bone marrow cells appears to be safe, as there have been no complications following implantation to date (11 patients followed up for more than 2 years), but longer follow-ups are required to determine that implantation is definitively safe. Also, we cannot yet confirm that the observed beneficial effects were due to the cell therapy. However, the outcomes following transplantation in acute patients, and in one chronic patient who was in stable condition for several months prior to cell implantation, are promising. It is evident that transplantation within a therapeutic window of 3-4 weeks following injury will play an important role in any type of stem cell SCI treatment. Trials involving a larger population of patients and different cell types are needed before further conclusions can be drawn.

Magnetic resonance tracking of human CD34+ progenitor cells separated by means of immunomagnetic selection and transplanted into injured rat brain.

Magnetic resonance imaging (MRI) provides a noninvasive method for studying the fate of transplanted cells in vivo. We studied whether superparamagnetic nanoparticles (CD34 microbeads), used clinically for specific magnetic sorting, can be used as a magnetic cell label for in vivo cell visualization. Human cells from peripheral blood were selected by CliniMACS CD34 Selection Technology (Miltenyi). Purified CD34+ cells were implanted into rats with a cortical photochemical lesion, contralaterally to the lesion. Twenty-four hours after grafting, the implanted cells were detected in the contralateral hemisphere as a hypointense spot on T2 weighted images; the hypointensity of the implant decreased during the first week. At the lesion site we observed a hypointensive signal 10 days after grafting that persisted for the next 3 weeks, until the end of the experiment. Prussian blue and anti-human nuclei staining confirmed the presence of magnetically labeled human cells in the corpus callosum and in the lesion 4 weeks after grafting. CD34+ cells were also found in the subventricular zone (SVZ). Human DNA (a human-specific 850 base pair fragment of alpha-satellite DNA from human chromosome 17) was detected in brain tissue sections from the lesion using PCR, confirming the presence of human cells. Our results show that CD34 microbeads superparamagnetic nanoparticles can be used as a magnetic cell label for in vivo cell visualization. The fact that microbeads coated with different commercially available antibodies can bind to specific cell types opens extensive possibilities for cell tracking in vivo.