Targeted therapy and allogeneic hematopoietic stem cell transplantation may cure patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous disorder with a diverse prognosis. About 70% of AML patients may achieve complete remission after conventional chemotherapy, but long-term outcome remains unsatisfactory. The development of molecular biology resulted in a better understanding of AML pathogenesis as well as it allowed us the introduction of targeted therapy. However, most AML patients still require the allogeneic hematopoietic stem cell transplantation (alloHSCT) to be cured. The long-term results of alloHSCT for AML depend on a variety of factors including the age at transplant, the presence of well-defined risk factors and disease status at transplant. It seems that the combination of targeted therapy with conventional chemotherapy and subsequent alloHSCT may be a chance for curing a significant proportion of AML patients

Treosulfan-based conditioning vs. low-dose busulfan-based conditioning for allogeneic hematopoietic stem cell transplantation: a cost-utility analysis in Poland

Introduction: In Poland, busulfan conditioning is used for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Cost-utility analyses comparing alternative conditioning regimens in patients undergoing allo-HSCT have not been conducted so far. Material and methods: A United Kingdom-based partitioned survival model was adapted to the Polish setting to compare treosulfan to low-dose busulfan conditioning regimen from the public payer’s perspective in Poland. Patient characteristics, overall survival (OS), event-free survival (EFS), and the rate of adverse events were obtained from the randomized MC-FludT.14/L trial. Parametric survival models of up to 5 years (the cure threshold), with subsequent mortality defined using survival of the general population of Poland adjusted for cancer survivors, were used to extrapolate OS and EFS beyond the trial duration. Published utilities were adjusted for age using age-dependent general population utilities. The costs of treatment, adverse events, and inpatient/outpatient care were assessed via official remuneration schemes. Results: Treosulfan-based conditioning outperformed low-dose busulfan, i.e. it was more effective with incremental quality-adjusted life years (QALY) of 0.78 and less expensive by 1,139 PLN per patient over the lifetime horizon. Deterministic sensitivity analyses revealed treosulfan was highly cost-effective (i.e. incremental cost-utility ratio was lower than the gross domestic product per capita in Poland) compared to low-dose busulfan, if most uncertain parameters are changed or alternative scenarios are implemented. The probability of treosulfan being cost-effective with a threshold of 155,514 PLN was 99.6%. Conclusions: Compared to low-dose busulfan, treosulfan is a highly cost-effective conditioning regimen for allo-HSCT patients ineligible for standard conditioning regimens

Mapping of the Sequences Directing Localization of the Drosophila Germ Cell-Expressed Protein (GCE)

Drosophila melanogaster germ cell-expressed protein (GCE) belongs to the family of bHLH-PAS transcription factors that are the regulators of gene expression networks that determine many physiological and developmental processes. GCE is a homolog of D. melanogaster methoprene tolerant protein (MET), a key mediator of anti-metamorphic signaling in insects and the putative juvenile hormone receptor. Recently, it has been shown that the functions of MET and GCE are only partially redundant and tissue specific. The ability of bHLH-PAS proteins to fulfill their function depends on proper intracellular trafficking, determined by specific sequences, i.e. the nuclear localization signal (NLS) and the nuclear export signal (NES). Nevertheless, until now no data has been published on the GCE intracellular shuttling and localization signals. We performed confocal microscopy analysis of the subcellular distribution of GCE fused with yellow fluorescent protein (YFP) and YFP-GCE derivatives which allowed us to characterize the details of the subcellular traffic of this protein. We demonstrate that GCE possess specific pattern of localization signals, only partially consistent with presented previously for MET. The presence of a strong NLS in the C-terminal part of GCE, seems to be unique and important feature of this protein. The intracellular localization of GCE appears to be determined by the NLSs localized in PAS-B domain and C-terminal fragment of GCE, and NESs localized in PAS-A, PAS-B domains and C-terminal fragment of GCE. NLSs activity can be modified by juvenile hormone (JH) and other partners, likely 14-3-3 proteins

Analysis and influence of anti-HLA antibodies after allogeneic hematopoietic stem cell transplantation from HLA-mismatched unrelated donors

Przeciwciała skierowane przeciw głównemu układowi zgodności tkankowej są istotnym czynnikiem odpowiedzialnym za odrzucenie przeszczepu w przypadku transplantacji narządów litych. Ich wpływ na wyniki allogenicznego przeszczepienia komórek krwiotwórczych, szczególnie od dawcy niezgodnego w układzie HLA, nie został dotychczas poznany. Wobec wzrastającej liczby allotransplantacji komórek krwiotwórczych od dawców niespokrewnionych nie w pełni zgodnych w układzie HLA, zaistniała potrzeba zbadania występowania oraz wpływu przeciwciał anty-HLA na wyniki procedury przeszczepowej. Celem naszej pracy było zbadanie występowania, swoistości oraz wpływu przeciwciał anty-HLA na wyniki przeszczepienia macierzystych komórek krwiotwórczych od dawców niespokrewnionych nie w pełni zgodnych w układzie HLA z biorcą przeszczepu. Do badania włączono 30 pacjentów poddanych transplantacji komórek krwiotwórczych w Klinice Hematologii i Transplantacji Szpiku SUM w Katowicach w latach 2001–2007. Przeciwciała anty-HLA były wykrywane przy użyciu techniki DynaChip w surowicach pobranych od chorych w różnym czasie od przeprowadzonej procedury przeszczepowej. Technika DynaChip łączy w sobie zmodyfikowaną metodę ELISA z techniką microchipów wykorzystującą rozpuszczalne, oczyszczone glikoproteiny HLA zarówno klasy I, jak i II, opłaszczone na powierzchni studzienek. Wstępne obserwacje wskazują, że po allotransplantacji są wytwarzane przeciwciała skierowane przeciw głównemu układowi zgodności tkankowej i mogą one mieć potencjalny wpływ na wyniki procedury transplantacyjnej.Antibodies against human leukocyte antigen (anti-HLA Abs) are important factors responsible for graft rejection in solid organ transplantation, but their role in allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unknown. As the number of patients who are treated with HLA-mismatched HSCT (including cord blood, haploidentical and unrelated HSCTs) constantly increases, the presence and influence of anti-HLA antibodies on the HSCT outcome is unknown. Thus we have examined incidence and influence of anti-HLA antibodies on outcomes of allo-HSCT from HLAmismatched unrelated donors. Abs were identified in sera collected from 30 recipients. We have used automated DynaChip assay which uses microchips bearing purified class I and II HLA antigens for detection of anti-HLA Abs. The preliminary results indicate that anti-HLA Abs appear post transplant in mismatched allo-HSCT recipients and may be potentially responsible for the occurrence of post-transplant complications

Badanie chimeryzmu specyficznego liniowo po allogenicznym przeszczepieniu komórek macierzystych

IntroductionDonor lineage-specific chimerism of hematopoietic cells enables very precise monitoring of engraftment in selected cell lines after allogeneic stem cell transplantation (allo-SCT).Materials and methodsThe study group consisted of 12 acute leukemia patients who underwent allo-SCT in the Department of Hematology and Bone Marrow Transplantation in Katowice, Poland. Lineage-specific chimerism was assessed in B cells (CD19+ CD38−/+), plasma cells (CD19+ CD38++), T cells (CD3+ or CD7+ CD56−), monocytes (CD14+), and immature progenitor cells deriving from myeloid line (CD34+CD19). We also assessed erythrocyte chimerism by flow cytometry.ResultsAll patients engrafted. 8 out of 10 patients presented normal donor hematopoiesis. Lineage specific chimerism in these patients corresponded with chimerism analysis in unsorted material and with undetectable minimal residual disease (MRD). Relapse of the underlying disease was diagnosed in 2 patients. In both cases loss of donor chimerism occurred in leukemia specific cell line and corresponded with detectable MRD. One patient with secondary graft failure presented decreasing lineage specific chimerism in all subpopulations, with negative MRD status. In 10 patients normal hematopoiesis of donor-origin was assessed by flow cytometry. In one case no donor-derived erythrocytes were detected and the diagnosis of pure red cell aplasia was set.ConclusionsLineage specific chimerism as a method of high sensitivity and specificity allows for precise assessment of donor chimerism especially in clinically ambiguous situations. Assessment of erythrocyte chimerism by flow cytometry is a reliable method of monitoring erythroblastic line engraftment. Presented results are preliminary and the study is being continued

Role of Donor Activating KIR–HLA Ligand–Mediated NK Cell Education Status in Control of Malignancy in Hematopoietic Cell Transplant Recipients

AbstractSome cancers treated with allogeneic hematopoietic stem cell transplantation (HSCT) are sensitive to natural killer cell (NK) reactivity. NK function depends on activating and inhibitory receptors and is modified by NK education/licensing effect and mediated by coexpression of inhibitory killer-cell immunoglobulin-like receptor (KIR) and its corresponding HLA I ligand. We assessed activating KIR (aKIR)-based HLA I–dependent education capacity in donor NKs in 285 patients with hematological malignancies after HSCT from unrelated donors. We found significantly adverse progression-free survival (PFS) and time to progression (TTP) in patients who received transplant from donors with NKs educated by C1:KIR2DS2/3, C2:KIR2DS1, or Bw4:KIR3DS1 pairs (for PFS: hazard ratio [HR], 1.70; P = .0020, Pcorr = .0039; HR, 1.54; P = .020, Pcorr = .039; HR, 1.51; P = .020, Pcorr = .040; and for TTP: HR, 1.82; P = .049, Pcorr = .096; HR, 1.72; P = .096, Pcorr = .18; and HR, 1.65; P = .11, Pcorr = .20, respectively). Reduced PFS and TTP were significantly dependent on the number of aKIR-based education systems in donors (HR, 1.36; P = .00031, Pcorr = .00062; and HR, 1.43; P = .019, Pcorr = .038). Furthermore, the PFS and TTP were strongly adverse in patients with missing HLA ligand cognate with educating aKIR-HLA pair in donor (HR, 3.25; P = .00022, Pcorr = .00045; and HR, 3.82; P = .027, Pcorr = .054). Together, these data suggest important qualitative and quantitative role of donor NK education via aKIR-cognate HLA ligand pairs in the outcome of HSCT. Avoiding the selection of transplant donors with high numbers of aKIR-HLA-based education systems, especially for recipients with missing cognate ligand, is advisable

Embryonic and adult isoforms of XLAP2 form microdomains associated with chromatin and the nuclear envelope

Laminin-associated polypeptide 2 (LAP2) proteins are alternatively spliced products of a single gene; they belong to the LEM domain family and, in mammals, locate to the nuclear envelope (NE) and nuclear lamina. Isoforms lacking the transmembrane domain also locate to the nucleoplasm. We used new specific antibodies against the N-terminal domain of Xenopus LAP2 to perform immunoprecipitation, identification and localization studies during Xenopus development. By immunoprecipitation and mass spectrometry (LC/MS/MS), we identified the embryonic isoform XLAP2γ, which was downregulated during development similarly to XLAP2ω. Embryonic isoforms XLAP2ω and XLAP2γ were located in close association with chromatin up to the blastula stage. Later in development, both embryonic isoforms and the adult isoform XLAP2β were localized in a similar way at the NE. All isoforms colocalized with lamin B2/B3 during development, whereas XLAP2β was colocalized with lamin B2 and apparently with the F/G repeat nucleoporins throughout the cell cycle in adult tissues and culture cells. XLAP2β was localized in clusters on chromatin, both at the NE and inside the nucleus. Embryonic isoforms were also localized in clusters at the NE of oocytes. Our results suggest that XLAP2 isoforms participate in the maintenance and anchoring of chromatin domains to the NE and in the formation of lamin B microdomains