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10 result(s) for "Elmaagacli, Ahmet H."
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Cytomegalovirus induces HLA-class-II-restricted alloreactivity in an acute myeloid leukemia cell line
Cytomegalovirus (HCMV) reactivation is found frequently after allogeneic hematopoietic stem cell transplantation (alloSCT) and is associated with an increased treatment-related mortality. Recent reports suggest a link between HCMV and a reduced risk of cancer progression in patients with acute leukemia or lymphoma after alloSCT. Here we show that HCMV can inhibit the proliferation of the acute myeloid leukemia cell line Kasumi-1 and the promyeloid leukemia cell line NB4. HCMV induced a significant up-regulation of HLA-class-II-molecules, especially HLA-DR expression and an increase of apoptosis, granzyme B, perforin and IFN-γ secretion in Kasumi-1 cells cocultured with peripheral blood mononuclear cells (PBMCs). Indolamin-2,3-dioxygenase on the other hand led only to a significant dose-dependent effect on IFN-γ secretion without effects on proliferation. The addition of CpG-rich oligonucleotides and ganciclovir reversed those antiproliferative effects. We conclude that HCMV can enhance alloreactivity of PBMCs against Kasumi-1 and NB4 cells in vitro. To determine if this phenomenon may be clinically relevant further investigations will be required.
Gene profiling of growth factor independence 1B gene (Gfi-1B) in leukemic cells
To investigate the molecular effects of growth factor independence 1B (Gfi-1B), a transcription factor essential for the development of hematopoietic cells and differentiation of erythroid and megakaryocytic lineages, the naturally Gfi-1B overexpressing cell line K562 was cultured in the presence of Gfi-1B target-specific small interfering RNA (siRNA). SiRNA treatment significantly knocked down Gfi-1B expression with an efficiency of nearly 90%. Analysis of the siRNA silencing protocol by colony-forming units ensured that it was not cytotoxic. Samples from Gfi-1B overexpressing cells and cells with knocked-down Gfi-1B were analyzed by oligonucleotide microarray technology and based upon rigorous statistical analysis of the data; relevant genes were chosen for confirmation by reserve transcriptase-polymerase chain reaction, including MYC/MYCBP and CDKN1A. Interestingly, transcripts within components of the signalling cascade of immune cells (PLD1, LAMP1, HSP90, IL6ST), of the tyrosine kinase pathway (TPR, RAC3) and of the transcription factors (RAC3, CEP290, JEM-1, ATR, MYC, SMC3, RARA, RBBP6) were found to be differentially expressed in Gfi-1B overexpressing cells compared to controls. Individual genes such as ZDHHC17, DMXL1, ZNF292 were found to be upregulated in Gfi-1B overexpressing cells. In addition, down-regulated transcripts showed cell signaling transcripts for several chemokine gene members including GNAL, CXCL5, GNL3L, GPR65, TMEM30, BCL11B and transcription factors (GTF2H3, ATXN3). In conclusion, several essential cell signalling factors, as well as transcriptional and post-translational regulation genes were differentially expressed in cells that overexpressed Gfi-1B compared to control cells with knocked-down Gfi-1B. Our data indicate that Gfi-1B signalling is important for commitment and maturation of hematopoietic cell populations.
Real-time PCR for monitoring minimal residual disease and chimerism in patients after allogeneic transplantation
Real-time PCR is a new fluorometric method for cycle-to-cycle quantification of PCR product growth rates. The real-time PCR method is fast and associated with a high reproducibility rate. It is used more often for monitoring MRD and chimerism in patients after allogeneic stem cell transplantation (SCT). There are real-time PCR methods for patients with CML, AML and ALL patients with inv(16), t(8;21), t(15;17); t(1;19) and other chromosomal aberrations. For patients with AML monitoring MRD is useful to identify patients who were at high risk for relapse after receiving chemotherapy. In patients with CML monitoring MRD might be helpful to assess success of after allogeneic SCT, or response to therapies with interferon alfa or STI 571. We found, that it is possible to estimate the relapse stage in CML after SCT by the amount of bcr-abl fusion transcript detected using a real-time PCR method. The median measured bcr-abl amount differ significantly (P<0.001) between the various stages, which has relevant clinical implications because it enables early therapeutic decisions in relapsing patients after transplant as e.g. the application of DLI to induce graft-versus-leukemia effects. Using real-time PCR it is possible to detect differences at alleles between recipient and donor at a single nucleotide basis (SNP) for chimerism analysis. The real-time PCR method enables to achieve a high a sensitivity of up to 1x10(-4), which is much more sensitive than all other chimerism methods including VNTR-PCR, STR-PCR. Furthermore, chimerism in male recipients with a female donor can be monitored also by detecting y-chromosome specific sequences by real-time PCR after transplant, which might be the most sensitive method to detect host type gene sequences. All in all, new real-time PCR methods offer a fast, reliable and very sensitive method to evaluate MRD and chimerism in patients after allogeneic SCT and therefore, to help to identify patients who are at high risk for leukemic relapse.
Outcome of hematopoietic stem cell transplantation in patients with atypical chronic myeloid leukemia
Atypical chronic myeloid leukemia (aCML) occurs rarely and is associated with a poor prognosis when treated with conventional chemotherapy. We evaluated the outcome of aCML after allogeneic hematopoietic stem cell transplantation (HSCT). Nine patients were transplanted from HLA-identical siblings (n = 4), HLA-compatible unrelated donors (n = 4) or twin brother (n = 1). Median follow-up was 55 months after transplant (range, 9.1-118.1 months). One patient who was transplanted in advanced disease with bone marrow from his twin brother relapsed 19 months post transplant. This patient was successfully retransplanted from the original donor. All patients remained in complete remission. Analysis of the leukocyte chimerism of peripheral white blood cells and bone marrow buffy coat cells by VNTR-polymerase chain reaction (PCR) and single-nucleotide polymorphism real-time PCR revealed complete chimerism in all patients who had received an allogeneic transplant. One patient suffering from cerebral toxoplasmosis died 9 months post transplant. All other patients were alive at the time of analysis. Our findings suggest that the outcome of allogeneic or syngeneic transplantation in patients with aCML may not be worse than the outcome of transplantation for BCR-ABL-positive CML.
Response-adapted lenalidomide maintenance in newly diagnosed myeloma: results from the phase III GMMG-MM5 trial
The MM5 trial aimed at demonstrating a progression-free survival (PFS) difference in continued vs. response-adapted (in case of complete response, CR) lenalidomide (LEN) maintenance therapy (MT) in newly diagnosed, transplant-eligible multiple myeloma (MM). Patients were equally randomized to receive induction therapy with PAd (bortezomib/doxorubicin/dexamethasone) or VCD (bortezomib/cyclophosphamide/dexamethasone), high-dose melphalan and autologous blood stem cell transplantation, and LEN consolidation, followed by either LEN MT for a fixed duration of 2 years (LEN-2Y) or until achievement of CR (LEN-CR, intention-to-treat population n = 502): arms A1:PAd + LEN-2Y (n = 125), B1:PAd + LEN-CR (n = 126), A2:VCD + LEN-2Y (n = 126), B2:VCD + LEN-CR (n = 125). In the LEN-CR group (B1 + B2), n = 88/17.5% patients did not start or discontinued LEN MT due to CR. There was no PFS (p = 0.60, primary endpoint) nor overall survival (OS) (p = 0.15) difference between the four study arms. On pooled LEN MT strategies, OS (hazard ratio, hazard ratio [HR] = 1.42, p = 0.03) but not PFS (HR = 1.15, p = 0.20) was shorter in LEN-CR (B1 + B2) vs. LEN-2Y (A1 + A2) groups. PFS was shortened on landmark analyses from the start of LEN MT in patients being in CR in the LEN-CR group (LEN-CR vs. LEN-2Y, HR = 1.84, p = 0.02). OS from first progression was shortened in the LEN-CR vs. LEN-2Y group (HR = 1.60, p = 0.01). LEN MT should be applied beyond CR for at least 2 years.
Bortezomib-based induction, high-dose melphalan and lenalidomide maintenance in myeloma up to 70 years of age
Intensive upfront therapy in newly-diagnosed multiple myeloma (MM) including induction therapy (IT), high-dose melphalan (MEL200), and autologous blood stem cell transplantation (ASCT) followed by consolidation and/or maintenance is mostly restricted to patients up to 65 years of age. Prospective phase III trial data in the era of novel agents for patients up to 70 years of age are not available. The GMMG-MM5 trial included 601 patients between 18 and 70 years of age, divided in three groups for the present analysis: ≤60 years (S1, n  = 353), 61–65 years (S2, n  = 107) and 66–70 years (S3, n  = 141). Treatment consisted of a bortezomib-containing IT, MEL200/ASCT, consolidation, and maintenance with lenalidomide. Adherence to treatment was similar among patients of the three age groups. Overall toxicity during all treatment phases was increased in S2 and S3 compared to S1 (any adverse event/any serious adverse event: S1:81.7/41.8% vs. S2:90.7/56.5% vs. S3:87.2/68.1%, p  = 0.05/<0.001). With respect to progression-free survival (log-rank p  = 0.73), overall survival (log-rank p  = 0.54) as well as time-to-progression (Gray’s p  = 0.83) and non-relapse mortality (Gray’s p  = 0.25), no differences were found between the three age groups. Our results imply that an intensive upfront therapy with a bortezomib-containing IT, MEL200/ASCT, lenalidomide consolidation, and maintenance should be applied to transplant-eligible MM patients up to 70 years of age.
What is the best path towards allogeneic transplantation in MDS and AML? A survey among German-spreaking centers for allogeneic hematopoietic stem cell transplantation
Allogeneic hematopoetic stem cell transplantation (allo SCT) is a treatment option with a unique chance of cure for patients with high-risk AML or MDS. However, the optimal path for an individual patient on its way to allo SCT is far from clear and subject of ongoing debates. Upfront transplantation “as soon as possible” competes with strategies to achieve deep remission or at least stabilization of the disease. In this context, we performed a survey among German transplant centers to assess their preferred strategies for patients before SCT in five typical scenarios of AML and MDS. We obtained replies from 22 centers, revealing a heterogenous use of possible strategies. Upfront transplantation was a preferred option (68%) in intermediate risk MDS, chemotherapy was preferred (64%) as bridging for AML in remission, whereas hypomethylating agents (HMA) and induction chemotherapy for relapsed AML were highly controversial. Further prospective evaluation of different options is desirable.
Prognostic Impact of Serum Free Light Chain Ratio Normalization in Patients with Multiple Myeloma Treated within the GMMG-MM5 Trial
We investigated the prognostic impact of time-dependent serum free light chain ratio (FLCr) normalization in 590 patients with secretory multiple myeloma (MM) during first-line treatment within the German-Speaking Myeloma Multicenter Group MM5 trial. Serum free light chains (sFLC) were assessed by the Freelite test at baseline, after induction, mobilization, autologous blood stem cell transplantation, consolidation and every three months during maintenance or follow up within two years after the start of maintenance. The proportion of patients with a normal or normalized FLCr increased from 3.6% at baseline to 23.2% after induction and 64.7% after consolidation. The achievement of FLCr normalization at any one time before the start of maintenance was associated with significantly prolonged progression-free survival (PFS) (p < 0.01, hazard ratio (HR) = 0.61, 95% confidence interval (95% CI) = 0.47–0.79) and overall survival (OS) (p = 0.02, HR = 0.67, 95% CI = 0.48–0.93) in multivariable time-dependent Cox regression analyses. Furthermore, reaching immune reconstitution, defined as the normalization of uninvolved immunoglobulins, before maintenance was associated with superior PFS (p = 0.04, HR = 0.77, 95% CI = 0.60–0.99) and OS (p = 0.01, HR = 0.59, 95% CI = 0.41–0.86). We conclude that FLCr normalization during therapy is an important favorable prognostic factor in MM. Therefore, we recommend serial measurements of sFLC during therapy until achieving FLCr normalization, even in patients with secretory MM.
A non-interventional study of the genetic polymorphisms of NOD2 associated with increased mortality in non-alcoholic liver transplant patients
Background Infections after liver transplantation are the main cause of death in the first year. Recent reports indicate that NOD2 gene mutations increase the risk for inflammatory bowl disease and the severity of graft-versus-host disease in bone marrow transplant patients. Data on polymorphisms in liver transplant patients are sparse. We analyzed 13 single-nucleotide polymorphisms (SNPs) of 13 different gene variants including the SNPs of NOD2 genes from liver recipients. The aim of the study was to evaluate the impact of the SNPs on dialysis-dependent kidney failure, the incidence of infections and patient survival. Methods During a period of 20-months, 231 patients were recruited in this non-interventional, prospective study. Thirteen different SNPs and their impact on the patients’ survival, infection rate, and use of dialysis were assessed. Results NOD 2 wildtype genes were protective with respect to the survival of non-alcoholic, cirrhotic transplant patients (3 year survival: 66.8% wildtype vs. 42.6% gene mutation, p = 0.026). This effect was not observed in alcoholic transplant recipients. The incidence of dialysis-dependent kidney failure and infection in the liver transplant patients was not influenced by NOD 2 gene polymorphisms. No effect was noted in the remaining 12 SNPs. Patients with early allograft dysfunction experienced significantly more infections, required dialysis and had significantly worse survival. In contrast, the donor-risk-index had no impact on the infection rate, use of dialysis or survival. Conclusion NOD2 gene variants seem to play a key role in non-alcoholic, liver transplant recipients. However these data should be validated in a larger cohort.