55 resultados para stem cell transplantation, leukemia, alloreactivity, HLA molecules, mismatch

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Telomere attrition induces cell senescence and apoptosis. We hypothesized that age-adjusted pretransplantation telomere length might predict treatment-related mortality (TRM) after hematopoietic stem cell transplantation (HSCT). Between 2000 and 2005, 178 consecutive patients underwent HSCT from HLA-identical sibling donors after myeloablative conditioning regimens, mainly for hematologic malignancies (n = 153). Blood lymphocytes' telomere length was measured by real-time quantitative PCR before HSCT. Age-adjusted pretransplantation telomere lengths were analyzed for correlation with clinical outcomes. After age adjustment, patients' telomere-length distribution was similar among all 4 quartiles except for disease stage. There was no correlation between telomere length and engraftment, GVHD, or relapse. The overall survival was 62% at 5 years (95% confidence interval [CI], 54-70). After a median follow-up of 51 months (range, 1-121 months), 43 patients died because of TRM. The TRM rate inversely correlated with telomere length. TRM in patients in the first (lowest telomere length) quartile was significantly higher than in patients with longer telomeres (P = .017). In multivariate analysis, recipients' age (hazard ratio, 1.1; 95% CI, .0-1.1; P = .0001) and age-adjusted telomere length (hazard ratio, 0.4; 95% CI; 0.2-0.8; P = .01) were independently associated with TRM. In conclusion, age-adjusted recipients' telomere length is an independent biologic marker of TRM after HSCT. (Blood. 2012;120(16):3353-3359)

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Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by T cell-mediated destruction of pancreatic beta cells, resulting in insulin deficiency and hyperglycaemia. Recent studies have described that apoptosis impairment during central and peripheral tolerance is involved in T1D pathogenesis. In this study, the apoptosis-related gene expression in T1D patients was evaluated before and after treatment with high-dose immunosuppression followed by autologous haematopoietic stem cell transplantation (HDI-AHSCT). We also correlated gene expression results with clinical response to HDI-AHSCT. We observed a decreased expression of bad, bax and fasL pro-apoptotic genes and an increased expression of a1, bcl-xL and cIAP-2 anti-apoptotic genes in patients' peripheral blood mononuclear cells (PBMCs) compared to controls. After HDI-AHSCT, we found an up-regulation of fas and fasL and a down-regulation of anti-apoptotic bcl-xL genes expression in post-HDI-AHSCT periods compared to pre-transplantation. Additionally, the levels of bad, bax, bok, fasL, bcl-xL and cIAP-1 genes expression were found similar to controls 2 years after HDI-AHSCT. Furthermore, over-expression of pro-apoptotic noxa at 540 days post-HDI-AHSCT correlated positively with insulin-free patients and conversely with glutamic acid decarboxylase autoantibodies (GAD65) autoantibody levels. Taken together, the results suggest that apoptosis-related genes deregulation in patients' PBMCs might be involved in breakdown of immune tolerance and consequently contribute to T1D pathogenesis. Furthermore, HDI-AHSCT modulated the expression of some apoptotic genes towards the levels similar to controls. Possibly, the expression of these apoptotic molecules could be applied as biomarkers of clinical remission of T1D patients treated with HDI-AHSCT therapy.

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Objective: The objective of this study was to analyze the incidence of and risk factors for healthcare-associated infections (HAI) among hematopoietic stem cell transplantation (HSCT) patients, and the impact of such infections on mortality during hospitalization. Methods: We conducted a 9-year (2001-2009) retrospective cohort study including patients submitted to HSCT at a reference center in Sao Paulo, Brazil. The incidence of HAI was calculated using days of neutropenia as the denominator. Data were analyzed using EpiInfo 3.5.1. Results: Over the 9-year period there were 429 neutropenic HSCT patients, with a total of 6816 days of neutropenia. Bloodstream infections (BSI) were the most frequent infection, presenting in 80 (18.6%) patients, with an incidence of 11.7 per 1000 days of neutropenia. Most bacteremia was due to Gram-negative bacteria: 43 (53.8%) cases were caused by Gram-negative species, while 33 (41.2%) were caused by Gram-positive species, and four (5%) by fungal species. Independent risk factors associated with HAI were prolonged neutropenia (odds ratio (OR) 1.07, 95% confidence interval (CI) 1.04-1.10) and duration of fever (OR 1.20, 95% CI 1.12-1.30). Risk factors associated with death in multivariate analyses were age (OR 1.02, 95% CI 1.01-1.43), being submitted to an allogeneic transplant (OR 3.08, 95% CI 1.68-5.56), a microbiologically documented infection (OR 2.96, 95% CI 1.87-4.6), invasive aspergillosis disease (OR 2.21, 95% CI 1.1-4.3), and acute leukemias (OR 2.24, 95% CI 1.3-3.6). Conclusions: BSI was the most frequent HAI, and there was a predominance of Gram-negative microorganisms. Independent risk factors associated with HAI were duration of neutropenia and fever, and the risk factors for a poor outcome were older age, type of transplant (allogeneic), the presence of a microbiologically documented infection, invasive aspergillosis, and acute leukemia. Further prospective studies with larger numbers of patients may confirm the role of these risk factors for a poor clinical outcome and death in this transplant population. (C) 2012 Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

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Despite the good response of stem cell transplant (SCT) in the treatment of multiple myeloma (MM), most patients relapse or do not achieve complete remission, suggesting that additional treatment is needed. We assessed the impact of thalidomide in maintenance after SCT in untreated patients with MM. A hundred and eight patients (<70 years old) were randomized to receive maintenance with dexamethasone (arm A; n = 52) or dexamethasone with thalidomide (arm B; n = 56; 200 mg daily) for 12 months or until disease progression. After a median follow-up of 27 months, an intention to treat analysis showed a 2-year progression-free survival (PFS) of 30% in arm A (95% CI 2238) and 64% in arm B (95% CI 5771; P = 0.002), with median PFS of 19 months and 36 months, respectively. In patients who did not achieve at least a very good partial response, the PFS at 2 years was significantly higher when in use of thalidomide (19 vs. 59%; P = 0.002). Overall survival at 2 years was not significantly improved (70 vs. 85% in arm A and arm B, respectively; P = 0.27). The addition of thalidomide to dexamethasone as maintenance improved the PFS mainly in patients who did not respond to treatment after SCT. Am. J. Hematol. (c) 2012 Wiley Periodicals, Inc.

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Type 1 diabetes mellitus is a chronic disease that results from the autoimmune response against pancreatic insulin producing beta cells. Apart of several insulin regimens, since the decade of 80s various immunomodulatory regimens were tested aiming at blocking some steps of the autoimmune process against beta cell mass and at promoting beta cell preservation. In the last years, some independent research groups tried to cure type 1 diabetes with an "immunologic reset" provided by autologous hematopoietic stem cell transplantation in newly diagnosed patients, and the majority of patients became free form insulin with increasing levels of C-peptide along the time. In this review, we discuss the biology of hematopoietic stem cells and the possible advantages and disadvantages related to the high dose immunosuppression followed by autologous hematopoietic stem cell transplantation.

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Abstract Background The use of stem cells to treat type 1 diabetes mellitus has been proposed for many years, both to downregulate the immune system and to provide β cell regeneration. Conclusion High dose immunosuppression followed by autologous hematopoietic stem cell transplantation is able to induce complete remission (insulin independence) in most patients with early onset type 1 diabetes mellitus.

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This is an integrative literature review with the aim of summarizing the prevention measures and treatment of thrombotic obstruction of long-term semi-implanted central venous catheters, in patients undergoing hematopoietic stem cell transplantation. The sample consisted of seven studies, being two randomized controlled clinical trials, three cohort studies and two case series. Regarding the prevention measures, one single study demonstrated effectiveness, which was a cohort study on the oral use of warfarin. In relation to the treatment measures, three studies evidenced effectiveness, one highlighted the efficacy of streptokinase or urokinase, one demonstrated the benefit of using low-molecular-weight heparin and the other treated the obstruction with heparin or urokinase. Catheter patency research shows a restricted evolution that does not follow the evolution of transplantations, mainly regarding nursing care.

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Purpose Patients with acute myeloid leukemia (AML) and FLT3/internal tandem duplication (FLT3/ITD) have poor prognosis if treated with chemotherapy only. Whether this alteration also affects outcome after allogeneic hematopoietic stem-cell transplantation (HSCT) remains uncertain. Patients and Methods We analyzed 206 patients who underwent HLA-identical sibling and matched unrelated HSCTs reported to the European Group for Blood and Marrow Transplantation with a diagnosis of AML with normal cytogenetics and data on FLT3/ITD (present: n = 120, 58%; absent: n = 86, 42%). Transplantations were performed in first complete remission (CR) after myeloablative conditioning. Results Compared with FLT3/ITD-negative patients, FLT3/ITD-positive patients had higher median leukocyte count at diagnosis (59 v 21 x 10(9)/L; P < .001) and shorter interval from CR to transplantation (87 v 99 days; P = .04). Other characteristics were similar in the two groups. At 2 years, relapse incidence (RI; +/- standard deviation) was higher (30% +/- 5% v 16% +/- 5%; P = .006) and leukemia-free survival (LFS) lower (58% +/- 5% v 71% +/- 6%; P = .04) in FLT3/ITD-positive compared with FLT3/ITD-negative patients. In multivariate analyses, FLT3/ITD led to increased RI (hazard ratio [HR], 3.4; 95% CI, 1.46 to 7.94; P = .005), as did older age, female sex, shorter interval between CR and transplantation, and higher number of chemotherapy courses before achieving CR. FLT3/ITD positivity was associated with decreased LFS (HR, 0.37; 95% CI, 0.19 to 0.73; P = .002), along with older age and higher number of chemotherapy courses before achieving CR. Conclusion FLT3/ITD adversely affected the outcome of HSCT in the same direction it does after chemotherapy; despite this, more than half of the patients harboring this mutation who received transplants were alive and leukemia free at 2 years. To further improve the results, use of FLT3 inhibitors before or after HSCT deserves investigation.

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We evaluated the effect of acute and chronic GVHD on relapse and survival after allogeneic hematopoietic SCT (HSCT) for multiple myeloma using non-myeloablative conditioning (NMA) and reduced-intensity conditioning (RIC). The outcomes of 177 HLA-identical sibling HSCT recipients between 1997 and 2005, following NMA (n = 98) or RIC (n = 79) were analyzed. In 105 patients, autografting was followed by planned NMA/RIC allogeneic transplantation. The impact of GVHD was assessed as a time-dependent covariate using Cox models. The incidence of acute GVHD (aGVHD; grades I-IV) was 42% (95% confidence interval (CI), 35-49%) and of chronic GVHD (cGVHD) at 5 years was 59% (95% CI, 49-69%), with 70% developing extensive cGVHD. In multivariate analysis, aGVHD (>= grade I) was associated with an increased risk of TRM (relative risk (RR) = 2.42, P = 0.016), whereas limited cGVHD significantly decreased the risk of myeloma relapse (RR = 0.35, P = 0.035) and was associated with superior EFS (RR = 0.40, P = 0.027). aGVHD had a detrimental effect on survival, especially in those receiving autologous followed by allogeneic HSCT (RR = 3.52, P = 0.001). The reduction in relapse risk associated with cGVHD is consistent with a beneficial graft-vs-myeloma effect, but this did not translate into a survival advantage. Bone Marrow Transplantation (2012) 47, 831-837; doi:10.1038/bmt.2011.192; published online 26 September 2011

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To address the prognostic value of minimal residual disease (MRD) before unrelated cord blood transplantation (UCBT) in children with acute lymphoblastic leukemia (ALL), we analyzed 170 ALL children transplanted in complete remission (CR) after myeloablative conditioning regimen. In all, 72 (43%) were in first CR (CR1), 77 (45%) in second CR (CR2) and 21 (12%) in third CR (CR3). The median interval from MRD quantification to UCBT was 18 days. All patients received single-unit UCBT. Median follow-up was 4 years. Cumulative incidence (CI) of day-60 neutrophil engraftment was 85%. CI of 4 years relapse was 30%, incidence being lower in patients with negative MRD before UCBT (hazard ratio (HR) = 0.4, P = 0.01) and for those transplanted in CR1 and CR2 (HR = 0.3, P = 0.002). Probability of 4 years leukemia-free survival (LFS) was 44%, (56, 44 and 14% for patients transplanted in CR1, CR2 and CR3, respectively (P = 0.0001)). Patients with negative MRD before UCBT had better LFS after UCBT compared with those with positive MRD (54% vs 29%; HR = 2, P = 0.003). MRD assessment before UCBT for children with ALL in remission allows identifying patients at higher risk of relapse after transplantation. Approaches that may decrease relapse incidence in children given UCBT with positive MRD should be investigated to improve final outcomes. Leukemia (2012) 26, 2455-2461; doi:10.1038/leu.2012.123

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Human adult stem cells (hASCs) offer a potentially renewable source of cell types that are easily isolated and rapidly expanded for use in regenerative medicine and cell therapies without the complicating ethical problems that are associated with embryonic stem cells. However, the eventual therapeutic use of hASCs requires that these cells and their derivatives maintain their genomic stability. There is currently a lack of systematic studies that are aimed at characterising aberrant chromosomal changes in cultured ASCs over time. However, the presence of mosaicism and accumulation of karyotypic abnormalities within cultured cell subpopulations have been reported. To investigate cytogenetic integrity of cultured human dental stem cell (hDSC) lines, we analysed four expanded hDSC cultures using classical G banding and fluorescent in situ hybridisation (FISH) with X chromosome specific probe. Our preliminary results revealed that about 70% of the cells exhibited karyotypic abnormalities including polyploidy, aneuploidy and ring chromosomes. The heterogeneous spectrum of abnormalities indicates a high frequency of chromosomal mutations that continuously arise upon extended culture. These findings emphasise the need for the careful analysis of the cytogenetic stability of cultured hDSCs before they can be used in clinical therapies.

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Adipose tissue-derived stem cells (ASCs) are an attractive source of stem cells with regenerative properties that are similar to those of bone marrow stem cells. Here, we analyze the role of ASCs in reducing the progression of kidney fibrosis. Progressive renal fibrosis was achieved by unilateral clamping of the renal pedicle in mice for 1 h; after that, the kidney was reperfused immediately. Four hours after the surgery, 2 x 10(5) ASCs were intraperitoneally administered, and mice were followed for 24 h posttreatment and then at some other time interval for the next 6 weeks. Also, animals were treated with 2 x 10(5) ASCs at 6 weeks after reperfusion and sacrificed 4 weeks later to study their effect when interstitial fibrosis is already present. At 24 h after reperfusion, ASC-treated animals showed reduced renal dysfunction and enhanced regenerative tubular processes. Renal mRNA expression of IL-6 and TNF was decreased in ASC-treated animals, whereas IL-4. IL-10, and HO-1 expression increased despite a lack of ASCs in the kidneys as determined by SRY analysis. As expected, untreated kidneys shrank at 6 weeks, whereas the kidneys of ASC-treated animals remained normal in size, showed less collagen deposition, and decreased staining for FSP-1, type I collagen, and Hypoxyprobe. The renal protection seen in ASC-treated animals was followed by reduced serum levels of TNF-alpha, KC, RANTES, and IL-1 alpha. Surprisingly, treatment with ASCs at 6 weeks, when animals already showed installed fibrosis, demonstrated amelioration of functional parameters, with less tissue fibrosis observed and reduced mRNA expression of type I collagen and vimentin. ASC therapy can improve functional parameters and reduce progression of renal fibrosis at early and later times after injury, mostly due to early modulation of the inflammatory response and to less hypoxia, thereby reducing the epithelial-mesenchymal transition.

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BACKGROUND & AIMS: Homozygous loss of function mutations in interleukin-10 (IL10) and interleukin-10 receptors (IL10R) cause severe infantile (very early onset) inflammatory bowel disease (IBD). Allogeneic hematopoietic stem cell transplantation (HSCT) was reported to induce sustained remission in 1 patient with IL-10R deficiency. We investigated heterogeneity among patients with very early onset IBD, its mechanisms, and the use of allogeneic HSCT to treat this disorder. METHODS: We analyzed 66 patients with early onset IBD (younger than 5 years of age) for mutations in the genes encoding IL-10, IL-10R1, and IL-10R2. IL-10R deficiency was confirmed by functional assays on patients' peripheral blood mononuclear cells (immunoblot and enzyme-linked immunosorbent assay analyses). We assessed the therapeutic effects of standardized allogeneic HSCT. RESULTS: Using a candidate gene sequencing approach, we identified 16 patients with IL-10 or IL-10R deficiency: 3 patients had mutations in IL-10, 5 had mutations in IL-10R1, and 8 had mutations in IL-10R2. Refractory colitis became manifest in all patients within the first 3 months of life and was associated with perianal disease (16 of 16 patients). Extraintestinal symptoms included folliculitis (11 of 16) and arthritis (4 of 16). Allogeneic HSCT was performed in 5 patients and induced sustained clinical remission with a median follow-up time of 2 years. In vitro experiments confirmed reconstitution of IL-10R-mediated signaling in all patients who received the transplant. CONCLUSIONS: We identified loss of function mutations in IL-10 and IL-10R in patients with very early onset IBD. These findings indicate that infantile IBD patients with perianal disease should be screened for IL-10 and IL-10R deficiency and that allogeneic HSCT can induce remission in those with IL-10R deficiency.

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The recently emerged concept of cancer stem cell (CSC) has led to a new hypothesis on the basis for tumor progression. Basically, the CSC theory hypothesizes the presence of a hierarchically organized and relatively rare cell population, which is responsible for tumor initiation, self-renewal, and maintenance, in addition to accumulation of mutation and resistance to chemotherapy. CSCs have recently been described in breast cancer. Different genetic markers have been used to isolate breast CSCs, none of which have been correlated with the tumorigenicity or metastatic potential of the cells, limiting their precise characterization and clinical application in the development of therapeutic protocols. Here, we sought for subpopulations of CSCs by analyzing 10 judiciously chosen stem cell markers in a normal breast cell line (MCF10-A) and in four human breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-435, and Hs578-T) displaying different degrees of metastatic and invasiveness potential. We were able to identify two markers, which are differentially expressed in nontumorigenic versus tumor cells. The CD90 marker was highly expressed in the malignant cell lines. Interestingly, the CD14 molecule displayed higher expression levels in the nontumorigenic cell line. Therefore, we demonstrated that these two markers, which are more commonly used to isolate and characterize stem cells, are differentially expressed in breast tumor cells, when compared with nontumorigenic breast cells. (C) 2012 International Society for Advancement of Cytometry