Frequent induction of chromosomal aberrations in in vivo skin fibroblasts after allogeneic stem cell transplantation: hints to chromosomal instability after irradiation

Abstract Abstract 1936 Background and aims: Graft-failure (GF) is an infrequent and poor complication of allogeneic stem cell transplantation (SCT). Strategies for reversing GF will depend on the options available in each situation. Patients and Methods: A questionnaire about GF was sent to all centers of the Grupo Español de Trasplante Hematopoyético (GETH). Fourteen Spanish institutions reported their GF from January 2006 to October 2010. Primary GF was defined as ANC >0.5×109/L not reached for three consecutive days by day +28 after SCT from peripheral blood (PB) or bone marrow (BM) progenitors and by day +60 after SCT from unrelated cord blood (UCB) progenitors. Secondary GF was defined as a recurrent ANC <0.5×109/L for at least 7days. Results: Eighty patients with GF were reported (median age 34 yr. [range: 1–68]; 54M/26F). Basal diseases were AML 30 (38%), ALL 14 (17%), lymphoproliferative disorder 12 (15%), myelodysplastic syndromes 9 (11%), myeloproliferative syndromes 7 (9%), aplastic anemia 5 (6%), and congenital disorders 3 (4%). Status of the neoplastic disease was: 1st/2nd CR or 1st chronic phase in 50 (62%) patients and >2nd CR or active disease in 30 (38%) patients. Conditioning therapy for 1st SCT was myeloablative in 45 (56%) and non-myeloablative in 35 (44%) patients. Donors were related in 35 (44%) and unrelated in 45 (56%). Progenitors were from mobilized PB in 45 (56%), UCB in 26 (33%) and BM in 9 (11%). At the time of GF, chimerism status (n=75) was donor complete in 6 (8%), mixed in 28 (35%) and from the patient in 41 (55%) individuals. Forty-five (56%) and 35 (44%) patients presented primary and secondary GF. Seventy-one patients received a second SCT from the same donor (31 patients [44%]), from a different donor (35 patients [49%]) or an autologous back-up (5 patients [7%]). The most frequent conditioning regimens (n=65) in second allogeneic stem cell infusion were fludarabine+ thymoglobulin (ATG) (19 [29%]), anti-lymphocyte immunoglobulin alone (9 [14%]) and cyclophosphamide+ATG (6 [9%]). ATG or alemtuzumab were used in 52 patients (80%) as part of the preparative regimen. Progenitors were from mobilized PB in 52 (79%), UCB in 8 (12%) and BM in 6 (9%) patients. Eleven (20%) and 2 (4%) out of 55 evaluable patients presented again primary or secondary GF. The median survival time from GF was 12 months [range: 1–23].The 5-yr. probability of survival was 28% (95%CI: 14%–42%) with a median follow-up for alive patients of 27 months [range: 1–103]. The 5-yr. non-relapse mortality was 47% [35%–59%]. There was a trend for a better survival in patients under 18 years-old. No other factors such as graft source, in vivo T-cell depletion or the conditioning regimen influenced on patient's survival. By competing risk estimation, the transplant-related mortality and the relapse probability at 5 years in the 66 patients that received a second transplant were 51% [95%CI: 38% – 63%] and 24% [95%CI: 10% – 41%]. Conclusions: The prognosis of GF after allogeneic SCT was poor, although some patients presented long survival if successful recovery of GF was obtained. The strategy adopted to treat GF has been heterogeneous. Younger age showed a trend for better survival in this series. Supported by grants P-EF/10 from FIJC and RD06/0020/1056 from RETICC. Disclosures: Sanz: Novartis: Speakers Bureau.

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Improved Vaccine Design For Adoptive Immunotherapy In Hematological Malignancies Through Chemically Modified Minor Histocompatibility Antigen Epitopes

Blood ◽

10.1182/blood.v122.21.5435.5435 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5435-5435

Author(s):

Rimke Oostvogels ◽

Rieuwert Hoppes ◽

Henk Lokhorst ◽

Robbert M Spaapen ◽

Huib Ovaa ◽

...

Keyword(s):

Amino Acids ◽

T Cells ◽

Stem Cell ◽

T Cell ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Allogeneic Stem Cell Transplantation ◽

Hematological Malignancies ◽

Ex Vivo

Abstract Allogeneic stem cell transplantation (allo-SCT), alone or followed by donor lymphocyte infusion (DLI), is a potentially curative treatment for various hematological malignancies. In an HLA-matched transplantation setting, the therapeutic graft-versus-tumor (GvT) effect is mediated by donor T-cells directed at minor histocompatibility antigens (mHags), which are HLA-bound polymorphic peptides. Unfortunately, most patients don’t achieve complete response or relapse after allogeneic stem cell transplantation and thus still require additional therapies. Immunotherapy aimed at hematopoietically restricted mHags could theoretically provide an ideal method to augment the GvT effect, without causing GvHD. The most relevant mHags for immunotherapy are those antigens that are only expressed on hematopoietic tissue, are presented by frequent HLA molecules and display an equally balanced population frequency. UTA2-1 and HA-1 are two of these most broadly applicable mHags identified up until now and are therefore included in on-going clinical trials of mHag-peptide loaded dendritic cell vaccination in patients with various hematological malignancies. Another method for mHag-based immunotherapy could be adoptive transfer of ex vivo cultured mHag-specific cytotoxic T lymphocytes (CTL). However, initial results of both methods, also from preclinical models and trials in patients with solid tumors, postulate the necessity for improved strategies for efficient ex vivo and in vivo induction of tumour specific CTLs. We here show for the HLA-A*02 restricted epitopes UTA2-1 and HA-1 that their MHC binding and consequent T cell reactivity can be improved through the incorporation of certain newly designed non-proteogenic amino acids at crucial MHC anchoring positions. With this novel approach we designed superior altered peptide ligands (APLs) for both epitopes, of which the best modifications not only increased MHC binding and stability, but also improved recognition by antigen specific T cells. Most importantly, these optimised peptides gave rise to superior antitumor T cell responses in vitro and in vivo in comparison to the native epitope, as they induced significantly enhanced proliferation of peptide-specific T cells with retained cytotoxic potential against malignant targets expressing the natural UTA2-1 antigen. Hence, these APLs designed with non-proteogenic amino acids with enhanced MHC-affinity and immunogenicity may improve the therapeutic outcome of mHag-based vaccination strategies, or can be utilized for ex vivo antigen-specific T cell enrichment and expansion for transfer into patients with haematological malignancies. Disclosures: Lokhorst: Genmab A/S: Consultancy, Research Funding; Celgene: Honoraria; Johnson-Cilag: Honoraria; Mudipharma: Honoraria.

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Immune reconstitution and cytomegalovirus infection after allogeneic stem cell transplantation: the important impact of in vivo T cell depletion

International Journal of Hematology ◽

10.1007/s12185-010-0597-6 ◽

2010 ◽

Vol 91 (5) ◽

pp. 877-885 ◽

Cited By ~ 43

Author(s):

Martin Schmidt-Hieber ◽

S. Schwarck ◽

A. Stroux ◽

S. Ganepola ◽

P. Reinke ◽

...

Keyword(s):

Stem Cell ◽

T Cell ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Allogeneic Stem Cell Transplantation ◽

Cytomegalovirus Infection ◽

Immune Reconstitution ◽

Cell Depletion ◽

T Cell Depletion

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Structural and Complex Chromosomal Aberrations Frequently Develop in Skin Fibroblasts after Allogeneic Stem Cell Transplantation.

Blood ◽

10.1182/blood.v106.11.1118.1118 ◽

2005 ◽

Vol 106 (11) ◽

pp. 1118-1118

Author(s):

Gero Massenkeil ◽

Petra Zschieschang ◽

Julia Pross ◽

Ingo Tamm ◽

Stephan Neuburger ◽

...

Keyword(s):

Stem Cell ◽

Stem Cell Transplantation ◽

Prospective Study ◽

Retrospective Analysis ◽

Cell Transplantation ◽

Chromosomal Aberrations ◽

Allogeneic Stem Cell Transplantation ◽

Secondary Neoplasms ◽

Cytogenetic Aberrations ◽

Skin Samples

Abstract Radiotherapy and chemotherapy are known to be mutagenic and may cause cytogenetic aberrations. Secondary neoplasms, which also arise after hematopoietic stem cell transplantation, are frequently associated with cytogenetic aberrations, which might be caused by DNA-alterations due to radio- and chemotherapy. Skin samples were examined for cytogenetic aberrations in patients after allogeneic stem cell transplantation (SCT). In a retrospective study skin samples were taken and examined from 18 patients 23–216 months (range 38 months) after allogeneic SCT. Underlying diagnoses were ALL (3 pts), AML (4 pts), CML (10 pts), MDS (2 pts), NHL (1 pt). In a prospective trial 20 pts were included. Skin biopsies were taken before conditioning, then at 3–6 months as well as 12 months after SCT. Median age before SCT was 32 years (range 16–49). Underlying diagnoses were ALL (4 pts), AML (3 pts), CML (7 pts), other CMPS (2 pts), MDS (3 pts), NHL (1 pt). Samples from all patients were cut into small pieces, placed at the bottom of three culture flasks and fibroblasts cultured according to standard techniques. Cytogenetic analysis was performed with trypsin-Giemsa banding technique. The number of cells with aberrant karyotypes, the number of clonal chromosome abnormalities, the number of breakpoints per aberrant metaphase, the preferential location of breakpoints in chromosome bands and the type of chromosomal lesions (e.g. translocations, deletions, duplications) were determined. In retrospective analysis, all 17 evaluable patients had cytogenetic aberrations, comprising 33–100% cells per patient. Aberrant cells had a median of 4 breakpoints per aberrant metaphase. In the prospective study, evaluable samples from 18 patients before SCT could be analysed and only 2/18 revealed cytogenetic aberrations. 3–6 months after allogeneic SCT, abnormal karyotypes were detected in 12/13 patients. 47–100% of analysed skin cells per patient had aberrant karyotypes (median 77%). Aberrant metaphases had 1–10 chromosomal breakpoints (median 3). 12 months after allogeneic SCT, all 11 evaluable skin samples demonstrated aberrant karyotypes, the number of abnormal cells being between 33–100% (median 63%). 2–5 clones were detected per patient. 1–9 breakpoints were found per aberrant metaphase. All chromosomal aberrations were structural (translocations, deletions, additions, inversion), most of them were balanced translocations; some aberrations were complex. The number of aberrant cells differed significantly before SCT on one hand and both time points after SCT (p<0.01) on the other hand, but not between the two timepoints after SCT (p=0.237). In univariate analysis, only acute leukemias (p=0.028) had a significant impact on chromosomal aberrations detected. 40–65 months after allogeneic SCT, none of the patients in the prospective study had developed secondary neoplasms and no carcinomas of the skin were detected. 1 patient in retrospective analysis had developed breast cancer 216 months after allogeneic SCT. In conclusion: Cytogenetic aberrations are very frequently induced in skin fibroblasts after TBI and high-dose chemotherapy in pts receiving allogeneic SCT. Aberrations persist and remain stable for prolonged periods after allogeneic SCT. The clinical implication of this finding needs longer follow-up.

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